Fixed permission on access problem.

/proc/pid/exe already seems to be a link to the absolute path to the
executable. This fixes bugs related to containerised applications.

.gitignore

@@ -1 +1,14 @@
 build/*
+.clang-tidy
+.cache
+test/protected/*
+test/perf*
+test/callgraph*
+test/openers
+test/opener/opener
+test/opener/opener.o
+test/.*
+*compile_commands.json
+src/gui/ui/*
+src/gui/*.o
+src/gui/icfs_dialogue

CONTENTS.md

@@ -0,0 +1,25 @@
+The source code is available in `src` directory:
+
+* `main.c` - main function.
+* `cc.h` - Convenient Containers library.
+* `fuse_operations.c`, `fuse_operations.h` - Implementation of FUSE operations.
+* `perm_permissions_table.c`, `perm_permissions_table.h` - implementation of permanent permissions table.
+* `proc_operations.c`, `proc_operations.c` - different utility functions that interface with procfs.
+* `temp_permissions_table.c` `temp_permissions_table.h` - implementation of temporary permission table.
+* `sourcefs.c`, `sourcefs.h`, `real_filename.h` - operations used to access the underlying filesystem.
+* `ui-socket.c` `ui-socket.h` - permission logic and interaction with access dialogues.
+* `gui/` directory - source code of the access dialogue.
+* Other files are dedicated to special data type definitions.
+
+`LICENSE` is the text of GPLv2 source code license.
+
+`Makefile` is code for the `make` build system.
+
+Tests are located in the `test` directory:
+
+* `test.bash` - script that tests ICFS correctness (see `README` for usage instructions)
+* `stress.bash` - helper script that loads ICFS with `open` operations.
+* `opener/` directory - source code for a scpecial program that tests whether file can be opened.
+* `mock/` directory - bash script that mocks behaviour of access dialogue.
+
+After building the program, make is going to create `build` directory where icfs and access dialogue executables will be located.

LICENSE

@@ -1,232 +1,339 @@
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+If distribution of executable or object code is made by offering
-Each contributor grants you a non-exclusive, worldwide, royalty-free patent license under the contributor's essential patent claims, to make, use, sell, offer for sale, import and otherwise run, modify and propagate the contents of its contributor version.
+access to copy from a designated place, then offering equivalent
-
+access to copy the source code from the same place counts as
-In the following three paragraphs, a “patent license” is any express agreement or commitment, however denominated, not to enforce a patent (such as an express permission to practice a patent or covenant not to sue for patent infringement). To “grant” such a patent license to a party means to make such an agreement or commitment not to enforce a patent against the party.
+distribution of the source code, even though third parties are not
-
+compelled to copy the source along with the object code.
-If you convey a covered work, knowingly relying on a patent license, and the Corresponding Source of the work is not available for anyone to copy, free of charge and under the terms of this License, through a publicly available network server or other readily accessible means, then you must either (1) cause the Corresponding Source to be so available, or (2) arrange to deprive yourself of the benefit of the patent license for this particular work, or (3) arrange, in a manner consistent with the requirements of this License, to extend the patent license to downstream recipients. “Knowingly relying” means you have actual knowledge that, but for the patent license, your conveying the covered work in a country, or your recipient's use of the covered work in a country, would infringe one or more identifiable patents in that country that you have reason to believe are valid.
+
-
+  4. You may not copy, modify, sublicense, or distribute the Program
-If, pursuant to or in connection with a single transaction or arrangement, you convey, or propagate by procuring conveyance of, a covered work, and grant a patent license to some of the parties receiving the covered work authorizing them to use, propagate, modify or convey a specific copy of the covered work, then the patent license you grant is automatically extended to all recipients of the covered work and works based on it.
+except as expressly provided under this License.  Any attempt
-
+otherwise to copy, modify, sublicense or distribute the Program is
-A patent license is “discriminatory” if it does not include within the scope of its coverage, prohibits the exercise of, or is conditioned on the non-exercise of one or more of the rights that are specifically granted under this License. You may not convey a covered work if you are a party to an arrangement with a third party that is in the business of distributing software, under which you make payment to the third party based on the extent of your activity of conveying the work, and under which the third party grants, to any of the parties who would receive the covered work from you, a discriminatory patent license (a) in connection with copies of the covered work conveyed by you (or copies made from those copies), or (b) primarily for and in connection with specific products or compilations that contain the covered work, unless you entered into that arrangement, or that patent license was granted, prior to 28 March 2007.
+void, and will automatically terminate your rights under this License.
-
+However, parties who have received copies, or rights, from you under
-Nothing in this License shall be construed as excluding or limiting any implied license or other defenses to infringement that may otherwise be available to you under applicable patent law.
+this License will not have their licenses terminated so long as such
-
+parties remain in full compliance.
-12. No Surrender of Others' Freedom.
+
-If conditions are imposed on you (whether by court order, agreement or otherwise) that contradict the conditions of this License, they do not excuse you from the conditions of this License. If you cannot convey a covered work so as to satisfy simultaneously your obligations under this License and any other pertinent obligations, then as a consequence you may not convey it at all. For example, if you agree to terms that obligate you to collect a royalty for further conveying from those to whom you convey the Program, the only way you could satisfy both those terms and this License would be to refrain entirely from conveying the Program.
+  5. You are not required to accept this License, since you have not
-
+signed it.  However, nothing else grants you permission to modify or
-13. Use with the GNU Affero General Public License.
+distribute the Program or its derivative works.  These actions are
-Notwithstanding any other provision of this License, you have permission to link or combine any covered work with a work licensed under version 3 of the GNU Affero General Public License into a single combined work, and to convey the resulting work. The terms of this License will continue to apply to the part which is the covered work, but the special requirements of the GNU Affero General Public License, section 13, concerning interaction through a network will apply to the combination as such.
+prohibited by law if you do not accept this License.  Therefore, by
-
+modifying or distributing the Program (or any work based on the
-14. Revised Versions of this License.
+Program), you indicate your acceptance of this License to do so, and
-The Free Software Foundation may publish revised and/or new versions of the GNU General Public License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns.
+all its terms and conditions for copying, distributing or modifying
-
+the Program or works based on it.
-Each version is given a distinguishing version number. If the Program specifies that a certain numbered version of the GNU General Public License “or any later version” applies to it, you have the option of following the terms and conditions either of that numbered version or of any later version published by the Free Software Foundation. If the Program does not specify a version number of the GNU General Public License, you may choose any version ever published by the Free Software Foundation.
+
-
+  6. Each time you redistribute the Program (or any work based on the
-If the Program specifies that a proxy can decide which future versions of the GNU General Public License can be used, that proxy's public statement of acceptance of a version permanently authorizes you to choose that version for the Program.
+Program), the recipient automatically receives a license from the
-
+original licensor to copy, distribute or modify the Program subject to
-Later license versions may give you additional or different permissions. However, no additional obligations are imposed on any author or copyright holder as a result of your choosing to follow a later version.
+these terms and conditions.  You may not impose any further
-
+restrictions on the recipients' exercise of the rights granted herein.
-15. Disclaimer of Warranty.
+You are not responsible for enforcing compliance by third parties to
-THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+this License.
-
+
-16. Limitation of Liability.
+  7. If, as a consequence of a court judgment or allegation of patent
-IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
+infringement or for any other reason (not limited to patent issues),
-
+conditions are imposed on you (whether by court order, agreement or
-17. Interpretation of Sections 15 and 16.
+otherwise) that contradict the conditions of this License, they do not
-If the disclaimer of warranty and limitation of liability provided above cannot be given local legal effect according to their terms, reviewing courts shall apply local law that most closely approximates an absolute waiver of all civil liability in connection with the Program, unless a warranty or assumption of liability accompanies a copy of the Program in return for a fee.
+excuse you from the conditions of this License.  If you cannot
-
+distribute so as to satisfy simultaneously your obligations under this
-END OF TERMS AND CONDITIONS
+License and any other pertinent obligations, then as a consequence you
-
+may not distribute the Program at all.  For example, if a patent
-How to Apply These Terms to Your New Programs
+license would not permit royalty-free redistribution of the Program by
-
+all those who receive copies directly or indirectly through you, then
-If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms.
+the only way you could satisfy both it and this License would be to
-
+refrain entirely from distribution of the Program.
-To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively state the exclusion of warranty; and each file should have at least the “copyright” line and a pointer to where the full notice is found.
+
-
+If any portion of this section is held invalid or unenforceable under
-     ICFS
+any particular circumstance, the balance of the section is intended to
-     Copyright (C) 2024  fedir
+apply and the section as a whole is intended to apply in other
-
+circumstances.
-     This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
+
-
+It is not the purpose of this section to induce you to infringe any
-     This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+patents or other property right claims or to contest validity of any
-
+such claims; this section has the sole purpose of protecting the
-     You should have received a copy of the GNU General Public License along with this program.  If not, see <https://www.gnu.org/licenses/>.
+integrity of the free software distribution system, which is
+implemented by public license practices.  Many people have made
+generous contributions to the wide range of software distributed
+through that system in reliance on consistent application of that
+system; it is up to the author/donor to decide if he or she is willing
+to distribute software through any other system and a licensee cannot
+impose that choice.
+
+This section is intended to make thoroughly clear what is believed to
+be a consequence of the rest of this License.
+
+  8. If the distribution and/or use of the Program is restricted in
+certain countries either by patents or by copyrighted interfaces, the
+original copyright holder who places the Program under this License
+may add an explicit geographical distribution limitation excluding
+those countries, so that distribution is permitted only in or among
+countries not thus excluded.  In such case, this License incorporates
+the limitation as if written in the body of this License.
+
+  9. The Free Software Foundation may publish revised and/or new versions
+of the General Public License from time to time.  Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+Each version is given a distinguishing version number.  If the Program
+specifies a version number of this License which applies to it and "any
+later version", you have the option of following the terms and conditions
+either of that version or of any later version published by the Free
+Software Foundation.  If the Program does not specify a version number of
+this License, you may choose any version ever published by the Free Software
+Foundation.
+
+  10. If you wish to incorporate parts of the Program into other free
+programs whose distribution conditions are different, write to the author
+to ask for permission.  For software which is copyrighted by the Free
+Software Foundation, write to the Free Software Foundation; we sometimes
+make exceptions for this.  Our decision will be guided by the two goals
+of preserving the free status of all derivatives of our free software and
+of promoting the sharing and reuse of software generally.
+
+                            NO WARRANTY
+
+  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
+FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
+OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
+PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
+OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
+TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
+PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
+REPAIR OR CORRECTION.
+
+  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
+REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
+INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
+OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
+TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
+YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
+PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGES.
+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
 Also add information on how to contact you by electronic and paper mail.
 
-If the program does terminal interaction, make it output a short notice like this when it starts in an interactive mode:
+If the program is interactive, make it output a short notice like this
+when it starts in an interactive mode:
 
-     ICFS  Copyright (C) 2024  fedir
+    Gnomovision version 69, Copyright (C) year name of author
-     This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
-     This is free software, and you are welcome to redistribute it under certain conditions; type `show c' for details.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
 
-The hypothetical commands `show w' and `show c' should show the appropriate parts of the General Public License. Of course, your program's commands might be different; for a GUI interface, you would use an “about box”.
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, the commands you use may
+be called something other than `show w' and `show c'; they could even be
+mouse-clicks or menu items--whatever suits your program.
 
-You should also get your employer (if you work as a programmer) or school, if any, to sign a “copyright disclaimer” for the program, if necessary. For more information on this, and how to apply and follow the GNU GPL, see <https://www.gnu.org/licenses/>.
+You should also get your employer (if you work as a programmer) or your
+school, if any, to sign a "copyright disclaimer" for the program, if
+necessary.  Here is a sample; alter the names:
 
-The GNU General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Lesser General Public License instead of this License. But first, please read <https://www.gnu.org/philosophy/why-not-lgpl.html>.
+  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
+  `Gnomovision' (which makes passes at compilers) written by James Hacker.
+
+  <signature of Ty Coon>, 1 April 1989
+  Ty Coon, President of Vice
+
+This General Public License does not permit incorporating your program into
+proprietary programs.  If your program is a subroutine library, you may
+consider it more useful to permit linking proprietary applications with the
+library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.

Makefile

@@ -1,13 +1,44 @@
 SHELL=/bin/bash
 
+# configurable options
+
+ifndef ($(SOURCES_DIR))
+	SOURCES_DIR := ./src
+endif
+
+ifndef ($(TESTS_DIR))
+	TESTS_DIR := ./tests
+endif
+
+ifndef ($(BUILD_DIR))
+	BUILD_DIR := ./build
+endif
+
+
+
 CC := gcc
 CXX := g++
 
-CFLAGS := -I/usr/include/fuse -D_FILE_OFFSET_BITS=64
-LDFLAGS := -lfuse3 -pthread
 
-ifdef DEBUG
+# dependencies
-	CFLAGS += -O0 -pedantic -Wall -Wextra -Wcast-align \
+
+PACKAGE_NAMES := fuse3 sqlite3
+
+ifeq ($(TEST), 1)
+	#	PACKAGE_NAMES += check # TODO: use check?
+endif
+
+
+# set up cflags and libs
+
+CFLAGS := -D_FILE_OFFSET_BITS=64
+LDFLAGS :=
+
+CFLAGS += $(shell pkg-config --cflags $(PACKAGE_NAMES))
+LDFLAGS += $(shell pkg-config --libs $(PACKAGE_NAMES))
+
+ifeq ($(DEBUG),1)
+	CFLAGS += -Og -pedantic -g -Wall -Wextra -Wcast-align \
 						-Wcast-qual -Wdisabled-optimization -Wformat=2 \
 						-Winit-self -Wlogical-op -Wmissing-declarations \
 						-Wmissing-include-dirs -Wredundant-decls -Wshadow \
@@ -19,20 +50,87 @@ else
 	LDFLAGS +=
 endif
 
-SOURCES_DIR := ./src
-BUILD_DIR := ./build
 
-build: $(BUILD_DIR)/main.o $(BUILD_DIR)/sourcefs.o $(BUILD_DIR)/ui-socket.o
+# set up targets 
+
+TARGETS := $(BUILD_DIR)/icfs
+
+ifeq ($(TEST), 1)
+	TARGETS += icfs_test
+endif
+
+ifneq ($(DIALOGUE), 0)
+	TARGETS += $(BUILD_DIR)/icfs_dialogue
+endif
+
+# build!
+
+default: $(TARGETS)
+
+.PHONY: clean icfs_test clean-icfs clean-icfs_dialogue install uninstall
+
+$(BUILD_DIR):
+	if [[ ! -d "$(BUILD_DIR)" ]]; then mkdir $(BUILD_DIR); fi
+
+$(BUILD_DIR)/icfs_dialogue:
+	make -C $(SOURCES_DIR)/gui TEST=$(TEST) DEBUG=$(DEBUG) SOURCES_DIR=$(shell realpath $(SOURCES_DIR)/gui) BUILD_DIR=$(shell realpath $(BUILD_DIR)) TESTS_DIR=$(shell realpath $(TESTS_DIR))
+
+$(BUILD_DIR)/icfs: $(BUILD_DIR)/main.o $(BUILD_DIR)/fuse_operations.o $(BUILD_DIR)/sourcefs.o $(BUILD_DIR)/ui-socket.o $(BUILD_DIR)/temp_permissions_table.o $(BUILD_DIR)/perm_permissions_table.o $(BUILD_DIR)/proc_operations.o
 	$(CC) $(CFLAGS) $^ $(LDFLAGS) -o $(BUILD_DIR)/icfs
 
-$(BUILD_DIR)/main.o: $(SOURCES_DIR)/main.c
+icfs_test: $(BUILD_DIR)/icfs
+	cd ./test && ./test.bash
+
+$(BUILD_DIR)/test_access_control.o: $(TESTS_DIR)/test_access_control.c $(BUILD_DIR)
+	$(CC) $(CFLAGS) -c $< $(LDFLAGS) -o $@
+
+$(BUILD_DIR)/main.o: $(SOURCES_DIR)/main.c $(BUILD_DIR)
 	$(CC) $(CFLAGS) -c $< $(LDFLAGS) -o $(BUILD_DIR)/main.o
 
-$(BUILD_DIR)/sourcefs.o: $(SOURCES_DIR)/sourcefs.c $(SOURCES_DIR)/sourcefs.h
+$(BUILD_DIR)/fuse_operations.o: $(SOURCES_DIR)/fuse_operations.c $(SOURCES_DIR)/fuse_operations.h $(BUILD_DIR)
 	$(CC) $(CFLAGS) -c $< $(LDFLAGS) -o $@
 
-$(BUILD_DIR)/ui-socket.o: $(SOURCES_DIR)/ui-socket.c $(SOURCES_DIR)/ui-socket.h
+$(BUILD_DIR)/sourcefs.o: $(SOURCES_DIR)/sourcefs.c $(SOURCES_DIR)/sourcefs.h $(SOURCES_DIR)/real_filename.h $(BUILD_DIR)
 	$(CC) $(CFLAGS) -c $< $(LDFLAGS) -o $@
 
-clean:
+$(BUILD_DIR)/ui-socket.o: $(SOURCES_DIR)/ui-socket.c $(SOURCES_DIR)/ui-socket.h $(BUILD_DIR)
-	rm $(BUILD_DIR)/*
+	$(CC) $(CFLAGS) -c $< $(LDFLAGS) -o $@
+
+$(BUILD_DIR)/temp_permissions_table.o: $(SOURCES_DIR)/temp_permissions_table.c $(SOURCES_DIR)/temp_permissions_table.h $(BUILD_DIR)
+	$(CC) $(CFLAGS) -c $< $(LDFLAGS) -o $@
+
+$(BUILD_DIR)/perm_permissions_table.o: $(SOURCES_DIR)/perm_permissions_table.c $(SOURCES_DIR)/perm_permissions_table.h $(BUILD_DIR)
+	$(CC) $(CFLAGS) -c $< $(LDFLAGS) -o $@
+
+$(BUILD_DIR)/proc_operations.o: $(SOURCES_DIR)/proc_operations.c $(SOURCES_DIR)/proc_operations.h $(BUILD_DIR)
+	$(CC) $(CFLAGS) -c $< $(LDFLAGS) -o $@
+
+CLEAN_TARGETS=clean-icfs
+
+ifneq ($(DIALOGUE), 0)
+	CLEAN_TARGETS += clean-icfs_dialogue
+endif
+
+clean: $(CLEAN_TARGETS)
+
+clean-icfs:
+	rm $(BUILD_DIR)/*.o $(BUILD_DIR)/icfs
+
+clean-icfs_dialogue:
+		make -C $(SOURCES_DIR)/gui clean SOURCES_DIR=$(shell realpath $(SOURCES_DIR)/gui) BUILD_DIR=$(shell realpath $(BUILD_DIR)) TESTS_DIR=$(shell realpath $(TESTS_DIR))
+
+install: $(BUILD_DIR)/icfs $(BUILD_DIR)/icfs_dialogue
+	@echo "Install script needs superuser permission to:"
+	@printf "\t1. Move executables to /usr/bin.\n"
+	@printf "\t2. Create \"icfs\" user.\n"
+	@printf "\t3. Set the setuid bit of icfs executable.\n"
+	sudo cp $(BUILD_DIR)/icfs /usr/bin/icfs && sudo cp $(BUILD_DIR)/icfs_dialogue /usr/bin/icfs_dialogue
+	id -u icfs &>/dev/null || sudo useradd --system --user-group icfs
+	sudo chown icfs: /usr/bin/icfs && sudo chmod 4755 /usr/bin/icfs && sudo chmod 755 /usr/bin/icfs_dialogue
+	@read -p "Create /etc/icfs directory for permission databases [y/N]: " permd; if [[ $$permd == "y" ]]; then echo "sudo mkdir /etc/icfs && sudo chown :icfs /etc/icfs && sudo chmod g+rw,o= /etc/icfs;"; sudo mkdir /etc/icfs && sudo chown icfs:icfs /etc/icfs && sudo chmod g+rw,o= /etc/icfs; fi
+
+uninstall:
+	@echo "Install script needs superuser permission to remove executables in /usr/bin"
+	sudo rm -f /usr/bin/icfs /usr/bin/icfs_dialogue
+	@read -p "Remove /etc/icfs directory [y/N]: " permd; if [[ $$permd == "y" ]]; then echo "sudo rm -rf /etc/icfs"; sudo rm -rf /etc/icfs; fi
+

README.md

@@ -1,15 +1,12 @@
+
 # ICFS -- Interactively Controlled File System
 
+> [!IMPORTANT]  
+> If you need the version that correponds to the thesis attachment, go [here](https://git.umbrasolis.de/fedir/ICFS/src/commit/2f4f1a0a569704b770f50b3e7cf39c09b9b8381a). This version contains corrections of errors that the opponent brought to my attention.
+
 ## Motivation
 
-Traditional access control mechanisms in operating systems allow the same level
+Traditional access control mechanisms in operating systems allow the same level of access to all processes running on behalf of the same user. This typically enables malicious processes to read and/or modify all data accessible to the user running a vulnerable application. It can be dealt using various mandatory access control mechanisms, but these are often complicated to configure and are rarely used in common user oriented scenarios. This thesis focuses on design and implementation of a file system layer which delegates the decision to allow or deny access to a file system object by a specific process to the user.
-of access to all processes running on behalf of the same user. This typically
-enables malicious processes to read and/or modify all data accessible to the
-user running a vulnerable application. It can be dealt using various mandatory
-access control mechanisms, but these are often complicated to configure and are
-rarely used in common user oriented scenarios. This thesis focuses on design
-and implementation of a file system layer which delegates the decision to allow
-or deny access to a file system object by a specific process to the user.
 
 ## Goals
 
@@ -17,6 +14,73 @@ or deny access to a file system object by a specific process to the user.
 - Implement the solution using the FUSE framework
 - Test the solution and demonstrate its benefits
 
+## Building
+
+- Install dependencies
+  - libfuse3
+    - Debian: `sudo apt install fuse3 libfuse3-dev`
+  - SQLite3
+    - Debian: `sudo apt install libsqlite3-dev`
+  - GTK4, libadwaita
+    - Debian: `sudo apt install libgtk-4-dev libadwaita-1-dev`
+  - Build tools
+    - Debian: `sudo apt install gcc make pkg-config`
+- Build using `make`:
+  - In the project directory: `make`
+  - Add `DEBUG=1` to show more compiler warnings.
+  - Add `TEST=1` to also test the program.
+  - Add `DIALOGUE=0` to not compile the dialogue program.
+- Resulting binaries should appear in the `build` directory.
+
+## Installation
+
+- `make install`
+- Uninstall with `make uninstall`
+
+## Usage
+
+```
+Usage: icfs <FUSE arguments> [target directory] [path to the permanent permissions database] <ICFS arguments>
+ --no-grant-on-create - do not give any access permissions on file creation(incompatible with --perm-on-create)
+ --perm-on-create - automatically give permanent access permission to files a process creates (incompatible with --no-grant-on-create)
+```
+
+The filesystem will be mounted over the target directory, and ask user permission every time a file in that directory is opened. We highly recommend adding `-o default_permissions` to increase performance and add an additional security layer. If you have installed icfs along with `/etc/icfs` folder, you can create your permanent permission databases in this folder (you might want to do this, if your home folder does not have the "execute" permission for other users).
+
+### Development build
+
+Execute this command in the root directory of this project:
+
+```
+env PATH="$(realpath ./build):$PATH" build/icfs <FUSE arguments> [target directory] [path to permanent permission database]
+```
+
+The `env PATH="$(realpath ./build):$PATH"` adds the access dialogue program to PATH, allowing ICFS to call it seamlessly.
+
+#### Running tests
+
+ICFS includes a testing script in the `test` directory.
+
+You can run it **from `test` directory** by running:
+
+```
+./test.bash
+```
+
+All testing artifacts will be available in the appropriate folders after run. To test setuid capabilities too (**from `test` directory!!!**):
+
+```
+./test.bash --setuid
+```
+
+You can also test performance by adding `--performance` (**from `test` directory!!!**):
+
+```
+./test.bash --performance
+```
+
+***Important:*** **flags cannot be combined together (e.g. you can't add `--performance` and `--setuid`)**
+
 ## Docs
 
 - [Initial idea and motivation](./docs/bc-thesis-idea.md)
@@ -25,6 +89,6 @@ or deny access to a file system object by a specific process to the user.
 
 ## Credit
 
-_Student:_ Fedir Kovalov
+*Student:* Fedir Kovalov
 
-_Supervisor:_ RNDr. Jaroslav Janáček, PhD.
+*Supervisor:* RNDr. Jaroslav Janáček, PhD.

docs/bc-thesis-idea.md

@@ -1,66 +0,0 @@
-# File subsystem with process-specific file access control for Linux.
-## The problem
-When you run a program on Linux, it can access the same files as the user account that started it, which is usually overly permissive.
-
-For example, one may write a trojan, that would download all of your photos, documents, personal info, data of other programs, etc. and you wouldn't even have a way of knowing it happened.
-
-At the same time, you *sometimes* would like *some* programs to have access to *some* of your files, for example if you are applying for the university, you would like your text editor to have access to  application form, but you only need it when you are applying for a university, and you only need the editor to access this specific file.
-
-So you have to somehow control *when* and *which* programs can access *what* file.
-
-## Existing file access control solutions
-
-### Linux security modules
-Kernel modules such as SELinux and AppArmor can certainly enforce rules on *which* programs can access *what* files, which certainly helps. Unfortunately:
-* They are overcomplicated (especially SELinux).
-* They have to be compiled into the kernel.
-* They give permissions forever: you have to reset them manually.
-
-### Flatpaks, Snaps and similar namespace-based solutions
-When the programs themselves are isolated from the rest of the OS, it definitely helps to prevent unwanted access to the filesystem. However:
-
-* To even be able to override the default filesystem access permissions the user needs to use another app (flatseal for example) or to master the CLI tools.
-* They give permissions forever: you have to revoke them manually.
-* The program has to be packaged and distributed is a specific way, which is a developer's decision. 
-* **LOTS of apps need access to some files. Because the default permissions are regulated by the developer himself, it is usually easier to give entire filesystem access permissions, rather than select a specific folder that it needs.**
-
-## My idea to solve the problem
-Make a program using FUSE that would control processes' access to selected files by freezing the process and letting the user to choose whether to allow the access or not.
-
-From the point of view of the process files would appear completely normal, so no involvement of the developer is required.
-
-When a process calls `open()` on a file that our system controls, that process would be frozen. User then uses the system's interface to either allow (and then the file is opened normally), or deny access (and then the `open()` returns `EACCES`).
-
-Under the hood, the system's daemon would open some other file stored in a hidden directory with restricted "classic" POSIX permissions (I talk more about how those files are protected in the problems section). From now on, these files would be called "source files".
-
-The program would keep track processes' permissions, and allow repeated access to the same file, to avoid bothering the user excessively.
-
-Also, because the program is running fully within userspace, it will make it far easier to develop, interface with, install and distribute.
-
-## Problems
-
-See `bc-thesis-problems.md` .
-
-## (Proposed) time plan
-* before 31.10 - A sort of "security risk assessment" and therefore a review of requirements, since this kind of is a security project.
-* before 30.11 - Architecture and design.
-* before 28.01 - Implementation.
-* before 31.02 - Testing.
-* before 30.03 - The thesis itself.
-
-Rest of the time is reserved for unexpected problems.
-
-Since the "buisness analysis" and requirements are already more than half-ready, I am not including them.
-
-## Formal specification
-Name:
-
-`File subsystem with temporary, process-specific file access control policies for Linux.`
-
-Goal:
-
-`Develop and implement a virtual file subsystem that would manage and enforce temporary, process and file specific rules and policies regulated by the user's choice, therefore ensuring greater security by restricting arbitrary file access by processes.`
-
-[^1]: I haven't found any better information on that topic. The solutions mentioned seem overcomplicated.
-[^2]: Which is obtained through 22-nd field in /proc/\[pid\]/stat (see `man proc_pid_stat(5)`).
-[^3]: To the best of my knowledge.

docs/bc-thesis-problems.md

@@ -1,78 +0,0 @@
-
-# Problems
-## Keeping track of running processes
-Since [we can't simply be notified about random process's termination](https://stackoverflow.com/questions/15275366/how-to-get-notified-on-termination-of-some-another-process-in-linux)[^1], the question arises: how to keep track of the processes in the permission table? 
-If we don't delete a permission table entry exactly before the process finishes, another process, [intentionally](https://stackoverflow.com/questions/18122592/how-to-set-process-id-in-linux-for-a-specific-program) or not, gets the same PID, it would gain unauthorized access to files. 
-
-The solution I offer involves writing down process's start time:
-
-* Permission table will consist of entries $(pid, starttime, permission)$, where $pid$ is the process's PID, $starttime$ is the process's start time and $permission$ is the type of access the process is allowed (e.g. to which files).
-* When the process opens a file, search through the table.
-    + If an entry with the correct PID was found:
-        - If $starttime_{table} < starttime_{actual}$[^2], delete all the entries with that PID and file a permission request to the user -- the process that requested access is not the same because it has started after the original process who had this permission(and because their PIDs match, the original process had to end before this could start).
-        - Otherwise:
-        	* If the permission matches the request, open the file.
-        	* Otherwise file a new permission request.
-    + Otherwise file a new permission request.
-
-This approach should make "permission hijacking" practically impossible, as it would take a considerable amount of time just to approve the permission. Even if our permissions could be approved instantly it would still take a few scheduler cycles to execute the original program, so the new ones must have a later start time.
-
-This approach still has an issue: the table would be hoarded with old permissions, and therefore waste memory. This might be mitigated by regular cleanups (e.g. every time you create a new permission, check if the oldest one's process is still running)
-
-Another issue might be speed, because all of the table lookups take linear time. But considering that file opening isn't exactly a time-critical operation and that the table could be sorted by PID, it does not seem to be that big of an issue.
-
-## FUSE issues
-As mentioned in the initial idea, the source files have to be protected from external access in some way.
-
-Here I can see three solutions:
-
-1. Encrypting source files.
-2. Running our virtual filesystem daemon as a special user, and making all our source files only accessible to this special user, therefore processes would have no permissions to access the source files.
-3. Use some LSM's MAC policy to deny access to source files to any process except our daemon.
-
-The first solution would definitely be preferable from the standpoint of compatibility, as it requires no special configuration, and because it mitigates the issue the best, as the attacker has to get encryption keys from the memory. Moreover, it could allow us to deny access for processes running as `root`[^3]. However, implementing encryption seems to be way out of scope of this project.
-
-The second solution seems to work well in theory. There are some specific details to be clarified about it's implementation, but generally it seems to work out.
-
-Although the third solution looks like exactly what we are looking for, but it requires a kernel module that enforces MAC policies. Even though those modules are common on most distros, they are pretty different from each other, and I think their usage should be limited to being an additional layer on top of the second solution.
-
-## User interface
-From the description of the software, it remains unclear what type of user interaction design is appropriate. Do we make a CLI? GUI?
-
-I propose to deal with it like the [Transmission](https://github.com/transmission/transmission) did[^3] -- create the backend with an integrated CLI first, and then make GUI wrapper in GTK after (if there would be time, of course `:)` ).
-
-## Programs with CLI
-Programs that are run via shell can have an execution time of a fraction of a second, which means you would have to re-allow the access for them every time you run them.
-My solution is to give an option to set permissions for specific *sessions*, so that every command run from a specific terminal window would have the same permissions.
-Then the permission table would be populated with the session process's data (e.g. the shell), or maybe this would necessitate a separate table just for the sessions.
-That might also imply a creation of two CLI tools:
-
-* `sprequest [PERM]` -- request a certain permission for the session
-* `spdrop` -- drop all permissions given to the session
-
-## Too many files...
-It would be annoying to go and allow access for each program every time one of them opens a new file.
-For example, if the file subsystem looks like this:
-```
-Documents/
-| Work/
-| | horalky_secret_recipe.pdf
-| | colleagues.csv
-| Notes/
-| | set_theory.md
-| | Peano_axioms.md
-| | ...
-| | Cantor_theorem.md
-```
-If I want to view my notes, I would want allow my markdown editor the access to all the files in the `Documents/Notes` folder to make links work, but when I want to find a name of my colleague, I would like to only give the permission to the `Documents/Work/colleagues.csv` file.
-The solution is obvious: to give an option for the user to give permissions for the entire folder, not just a specific file. 
-
-## Other
-* Threads (not that big of a problem, but a complication nevertheless).
-* All of the permissions get reset after the process is ended, which is annoying. Perhaps it would be possible to implement permanent permissions through identifying programs by their executables' hashes/paths, but updates almost certainly make that impossible (unless we are modifying a package manager, which is clearly out of scope of this project).
-
-Another issue, severity of which I can't assess properly, is whether this idea fits the Informatics degree, as it does not seem to be as much of an experimental or "theoretical" idea. In my opinion it sill holds enough water to entertain the possibility though.
-
-[^1]: I haven't found any better information on that topic. The solutions mentioned seem overcomplicated.
-[^2]: Which is obtained through 22-nd field in /proc/\[pid\]/stat (see `man proc_pid_stat(5)`).
-[^3]: To the best of my knowledge.

docs/bc-thesis-specs.md

@@ -1,33 +0,0 @@
-# Formal specification
-
-## Name
-```
-Filesystem with Interactive Access Control for Linux
-```
-
-```
-Súborový systém s interaktívnym riadením prístupu pre Linux
-```
-
-## Note
-```
-Traditional access control mechanisms in operating systems allow the same level of access to all processes running on behalf of the same user. This typically enables malicious processes to read and/or modify all data accessible to the user running a vulnerable application. It can be dealt using various mandatory access control mechanisms, but these are often complicated to configure and are rarely used in common user oriented scenarios. This thesis focuses on design and implementation of a filesystem layer which delegates the decision to allow or deny access to a filesystem object by a specific process to the user.
-```
-
-```
-Tradičné mechanizmy riadenia prístupu v operačných systémoch povoľujú rovnakú úroveň prístupu všetkým procesom bežiacim v mene toho istého používateľa. Toto typicky umožňuje škodlivým procesom čítať a/alebo modifikovať všetky údaje prístupné používateľovi, ktorý spustil zraniteľnú aplikáciu. Dá sa to riešiť použitím rôznych mechanizmov povinného riadenia prístupu, no tieto sú často náročné na konfiguráciu a zriedkavo sa používajú v bežných scenároch orientovaných na používateľa. Táto práca sa zameriava na návrh a implementáciu vrstvy súborového systému, ktorá rozhodnutie povoliť alebo zakázať prístup k objektu súborového systému konkrétnym procesom deleguje na používateľa.
-```
-
-## Goal
-
-```
-- analyse the problem and design a solution
-- implement the solution using the FUSE framework
-- test the solution and demonstrate its benefits
-```
-
-```
-- analyzovať problém a navrhnúť riešenie
-- implementovať riešenie využitím FUSE
-- otestovať riešenie a demonštrovať jeho prínos
-```

src/access_t.h

@@ -0,0 +1,14 @@
+/*
+  ICFS: Interactively Controlled File System
+  Copyright (C) 2024-2025  Fedir Kovalov
+
+  This program can be distributed under the terms of the GNU GPLv2.
+  See the file LICENSE.
+*/
+
+#ifndef ACCESS_T_H
+#define ACCESS_T_H
+
+typedef enum { DENY, ALLOW, ALLOW_TEMP, DENY_TEMP, NDEF } access_t;
+
+#endif // !ACCESS_T_H

src/fuse_operations.c

@@ -0,0 +1,806 @@
+
+/*
+  FUSE: Filesystem in Userspace
+  Copyright (C) 2001-2007  Miklos Szeredi <miklos@szeredi.hu>
+  Copyright (C) 2011       Sebastian Pipping <sebastian@pipping.org>
+
+  ICFS: Interactively Controlled File System
+  Copyright (C) 2024-2025  Fedir Kovalov
+
+  This program can be distributed under the terms of the GNU GPLv2.
+  See the file LICENSE.
+*/
+
+#include "process_info.h"
+#include "real_filename.h"
+#include "set_mode_t.h"
+#include <assert.h>
+#include <stddef.h>
+#define FUSE_USE_VERSION 31
+
+#define _GNU_SOURCE
+
+#include <fuse3/fuse.h>
+
+#ifdef HAVE_LIBULOCKMGR
+#include <ulockmgr.h>
+#endif
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <unistd.h>
+#ifdef HAVE_SETXATTR
+#include <sys/xattr.h>
+#endif
+#include <sys/file.h> /* flock(2) */
+
+#include "fuse_operations.h"
+#include "proc_operations.h"
+#include "sourcefs.h"
+#include "temp_permissions_table.h"
+#include "ui-socket.h"
+
+int auto_create_perm = GRANT_TEMP;
+
+#define HAVE_UTIMENSAT
+
+/*
+ * Sets the default permission granted by file creation.
+ *
+ * @param val: the default permission to grant. Should be one of GRANT_TEMP,
+ * GRANT_TEM and 0. When set to 0, grants no permissions.
+ */
+void set_auto_create_perm(int val) { auto_create_perm = val; }
+
+static void *xmp_init(struct fuse_conn_info *conn, struct fuse_config *cfg) {
+  (void)conn;
+  cfg->use_ino = 1;
+  cfg->nullpath_ok = 1;
+
+  /* parallel_direct_writes feature depends on direct_io features.
+     To make parallel_direct_writes valid, need either set cfg->direct_io
+     in current function (recommended in high level API) or set fi->direct_io
+     in xmp_create() or xmp_open(). */
+  cfg->direct_io = 1;
+#if FUSE_VERSION > FUSE_MAKE_VERSION(3, 14)
+  cfg->parallel_direct_writes = 1;
+#endif
+
+  /* Pick up changes from lower filesystem right away. This is
+     also necessary for better hardlink support. When the kernel
+     calls the unlink() handler, it does not know the inode of
+     the to-be-removed entry and can therefore not invalidate
+     the cache of the associated inode - resulting in an
+     incorrect st_nlink value being reported for any remaining
+     hardlinks to this inode. */
+  cfg->entry_timeout = 0;
+  cfg->attr_timeout = 0;
+  cfg->negative_timeout = 0;
+  fprintf(stderr, "%d\n", getpid());
+  assert(get_mountpoint() != NULL);
+  init_garbage_collector();
+
+  return NULL;
+}
+
+static int xmp_getattr(const char *path, struct stat *stbuf,
+                       struct fuse_file_info *file_info) {
+  int res;
+
+  (void)path;
+
+  if (file_info)
+    res = fstat(file_info->fh, stbuf);
+  else
+    res = source_stat(path, stbuf);
+  if (res == -1) {
+    perror("[ICFS] Stat failed");
+    return -errno;
+  }
+
+  return 0;
+}
+
+static int xmp_access(const char *path, int mask) {
+  int res = -1;
+
+  // if mask is F_OK, then we don't need to check the permissions
+  // (is that possible?)
+  //
+  // EDIT: now lie to the program by not telling it whether it can actually
+  // access the file.
+
+  /*
+  if (mask != F_OK) {
+    struct process_info proc_info;
+    struct fuse_context *context = fuse_get_context();
+
+    proc_info.PID = context->pid;
+    proc_info.name = get_process_name_by_pid(proc_info.PID);
+
+    // fprintf(stderr, "%s, %d\n", path, ask_access(path, pi));
+
+    if (!interactive_access(path, proc_info, 0)) {
+      free((void *)proc_info.name);
+      return -EACCES;
+    }
+
+    free((void *)proc_info.name);
+  }
+  */
+
+  res = source_access(path, mask);
+
+  if (res == -1) {
+    return -errno;
+  }
+
+  return 0;
+}
+
+static int xmp_readlink(const char *path, char *buf, size_t size) {
+  int res = -1;
+
+  res = readlink(path, buf, size - 1);
+  if (res == -1)
+    return -errno;
+
+  buf[res] = '\0';
+  return 0;
+}
+
+struct xmp_dirp {
+  DIR *dp;
+  struct dirent *entry;
+  off_t offset;
+};
+
+static int xmp_opendir(const char *path, struct fuse_file_info *fi) {
+  int res;
+  struct xmp_dirp *d = malloc(sizeof(struct xmp_dirp));
+  if (d == NULL)
+    return -ENOMEM;
+
+  d->dp = source_opendir(path);
+  if (d->dp == NULL) {
+    perror("[ICFS] Opendir failed");
+    res = -errno;
+    free(d);
+    return res;
+  }
+  d->offset = 0;
+  d->entry = NULL;
+
+  fi->fh = (unsigned long)d;
+  return 0;
+}
+
+static inline struct xmp_dirp *get_dirp(struct fuse_file_info *fi) {
+  return (struct xmp_dirp *)(uintptr_t)fi->fh;
+}
+
+/* Complete copy of the example method(no need to modify anything so far) */
+static int xmp_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
+                       off_t offset, struct fuse_file_info *fi,
+                       enum fuse_readdir_flags flags) {
+  struct xmp_dirp *d = get_dirp(fi);
+
+  (void)path;
+  if (offset != d->offset) {
+#ifndef __FreeBSD__
+    seekdir(d->dp, offset);
+#else
+    /* Subtract the one that we add when calling
+       telldir() below */
+    seekdir(d->dp, offset - 1);
+#endif
+    d->entry = NULL;
+    d->offset = offset;
+  }
+  while (1) {
+    struct stat st;
+    off_t nextoff;
+    // enum fuse_fill_dir_flags fill_flags = FUSE_FILL_DIR_DEFAULTS;
+    enum fuse_fill_dir_flags fill_flags = 0;
+
+    if (!d->entry) {
+      d->entry = readdir(d->dp);
+      if (!d->entry)
+        break;
+    }
+#ifdef HAVE_FSTATAT
+    if (flags & FUSE_READDIR_PLUS) {
+      int res;
+
+      res = fstatat(dirfd(d->dp), d->entry->d_name, &st, AT_SYMLINK_NOFOLLOW);
+      if (res != -1)
+        fill_flags |= FUSE_FILL_DIR_PLUS;
+    }
+#endif
+    if (!(fill_flags & FUSE_FILL_DIR_PLUS)) {
+      memset(&st, 0, sizeof(st));
+      st.st_ino = d->entry->d_ino;
+      st.st_mode = d->entry->d_type << 12;
+    }
+    nextoff = telldir(d->dp);
+#ifdef __FreeBSD__
+    /* Under FreeBSD, telldir() may return 0 the first time
+       it is called. But for libfuse, an offset of zero
+       means that offsets are not supported, so we shift
+       everything by one. */
+    nextoff++;
+#endif
+    if (filler(buf, d->entry->d_name, &st, nextoff, fill_flags))
+      break;
+
+    d->entry = NULL;
+    d->offset = nextoff;
+  }
+
+  return 0;
+}
+
+/* Complete copy of the example method(no need to modify anything so far) */
+static int xmp_releasedir(const char *path, struct fuse_file_info *fi) {
+  struct xmp_dirp *d = get_dirp(fi);
+  (void)path;
+  closedir(d->dp);
+  free(d);
+  return 0;
+}
+
+/*
+// TODO: make this work
+static int xmp_mknod(const char *path, mode_t mode, dev_t rdev) {
+  int res;
+
+  if (S_ISFIFO(mode))
+    res = mkfifo(path, mode);
+  else
+    res = mknod(path, mode, rdev);
+  if (res == -1)
+    return -errno;
+
+  return 0;
+}
+*/
+
+static int xmp_mkdir(const char *path, mode_t mode) {
+  int res = -1;
+
+  res = source_mkdir(path, mode);
+  if (res == -1) {
+    return -errno;
+  }
+
+  return 0;
+}
+
+static int xmp_unlink(const char *path) {
+  int res = -1;
+  struct process_info pi;
+  struct fuse_context *fc = fuse_get_context();
+
+  // ask the user for the permission for deleting the file
+  pi = get_process_info(fc->pid);
+
+  // fprintf(stderr, "%s, %d\n", path, ask_access(path, pi));
+
+  if (!interactive_access(path, pi, 0)) {
+    free(pi.name);
+    return -EACCES;
+  }
+  free(pi.name);
+
+  res = source_unlink(path);
+  if (res == -1)
+    return -errno;
+
+  return 0;
+}
+
+static int xmp_rmdir(const char *path) {
+  int res;
+
+  res = source_rmdir(path);
+  if (res == -1)
+    return -errno;
+
+  return 0;
+}
+
+static int xmp_symlink(const char *from, const char *to) {
+  int res;
+
+  res = source_symlink(from, to);
+  if (res == -1)
+    return -errno;
+
+  return 0;
+}
+
+static int xmp_rename(const char *from, const char *to, unsigned int flags) {
+  int res;
+
+  /* When we have renameat2() in libc, then we can implement flags */
+  if (flags)
+    return -EINVAL;
+
+  struct process_info pi;
+  struct fuse_context *fc = fuse_get_context();
+
+  pi = get_process_info(fc->pid);
+
+  // fprintf(stderr, "%s, %d\n", path, ask_access(path, pi));
+
+  if (!interactive_access(from, pi, 0)) {
+    free(pi.name);
+    return -EACCES;
+  }
+
+  // the "to" file may exist and the process needs to get persmission to modify
+  // it
+  if (source_access(to, F_OK) == 0 && !interactive_access(to, pi, 0)) {
+    free(pi.name);
+    return -EACCES;
+  }
+
+  free(pi.name);
+
+  res = source_rename(from, to);
+  if (res == -1)
+    return -errno;
+
+  return 0;
+}
+
+static int xmp_link(const char *from, const char *to) {
+  int res;
+  struct process_info pi;
+  struct fuse_context *fc = fuse_get_context();
+
+  pi = get_process_info(fc->pid);
+
+  // fprintf(stderr, "%s, %d\n", path, ask_access(path, pi));
+  if (!interactive_access(from, pi, 0)) {
+    free(pi.name);
+    return -EACCES;
+  }
+
+  // no need to check the access to the "to" file, see link(2)
+
+  free(pi.name);
+
+  res = source_link(from, to);
+  if (res == -1)
+    return -errno;
+
+  return 0;
+}
+
+static int xmp_chmod(const char *path, mode_t mode, struct fuse_file_info *fi) {
+  int res;
+  struct process_info pi;
+  struct fuse_context *fc = fuse_get_context();
+
+  pi = get_process_info(fc->pid);
+
+  // fprintf(stderr, "%s, %d\n", path, ask_access(path, pi));
+  if (!interactive_access(path, pi, 0)) {
+    free(pi.name);
+    return -EACCES;
+  }
+
+  free(pi.name);
+
+  if (fi)
+    res = fchmod(fi->fh, mode);
+  else
+    res = source_chmod(path, mode);
+  if (res == -1)
+    return -errno;
+
+  return 0;
+}
+
+/**
+ * This filesystem is not designed for multiuser operation (with
+ * allow_other option) so there is little point in having chown implemnted
+ */
+static int xmp_chown(const char *path, uid_t uid, gid_t gid,
+                     struct fuse_file_info *fi) {
+  int res;
+  struct process_info pi;
+  struct fuse_context *fc = fuse_get_context();
+
+  pi = get_process_info(fc->pid);
+
+  // fprintf(stderr, "%s, %d\n", path, ask_access(path, pi));
+  if (!interactive_access(path, pi, 0)) {
+    free(pi.name);
+    return -EACCES;
+  }
+
+  free(pi.name);
+
+  if (fi)
+    res = fchown(fi->fh, uid, gid);
+  else
+    res = source_chown(path, uid, gid);
+  if (res == -1)
+    return -errno;
+
+  return 0;
+}
+
+static int xmp_truncate(const char *path, off_t size,
+                        struct fuse_file_info *fi) {
+  int res;
+
+  if (fi)
+    res = ftruncate(fi->fh, size);
+  else
+    res = source_truncate(path, size);
+
+  if (res == -1)
+    return -errno;
+
+  return 0;
+}
+
+#ifdef HAVE_UTIMENSAT
+static int xmp_utimens(const char *path, const struct timespec ts[2],
+                       struct fuse_file_info *fi) {
+  int res;
+  struct process_info pi;
+  struct fuse_context *fc = fuse_get_context();
+
+  pi = get_process_info(fc->pid);
+
+  if (!interactive_access(path, pi, 0)) {
+    free(pi.name);
+    return -EACCES;
+  }
+
+  /* don't use utime/utimes since they follow symlinks */
+  if (fi)
+    res = futimens(fi->fh, ts);
+  else
+    res = source_utimens(path, ts, AT_SYMLINK_NOFOLLOW);
+  if (res == -1)
+    return -errno;
+
+  return 0;
+}
+#endif
+
+static int xmp_create(const char *path, mode_t mode,
+                      struct fuse_file_info *fi) {
+  int fd = -1;
+  struct process_info pi;
+  struct fuse_context *fc = fuse_get_context();
+
+  pi = get_process_info(fc->pid);
+
+  if (auto_create_perm != 0) {
+    if (!interactive_access(path, pi, auto_create_perm)) {
+      free(pi.name);
+      return -EACCES;
+    }
+  }
+
+  free(pi.name);
+
+  fd = source_create(path, fi->flags, mode);
+  if (fd == -1)
+    return -errno;
+
+  fi->fh = fd;
+  return 0;
+}
+
+static int xmp_open(const char *path, struct fuse_file_info *fi) {
+  int fd;
+  struct process_info pi;
+  struct fuse_context *fc = fuse_get_context();
+
+  pi = get_process_info(fc->pid);
+
+  // fprintf(stderr, "%s, %d\n", path, ask_access(path, pi));
+  if (!interactive_access(path, pi, 0)) {
+    free(pi.name);
+    return -EACCES;
+  }
+
+  free(pi.name);
+
+  fd = source_open(path, fi->flags);
+  if (fd == -1)
+    return -errno;
+
+  /* Enable direct_io when open has flags O_DIRECT to enjoy the feature
+     parallel_direct_writes (i.e., to get a shared lock, not exclusive lock,
+     for writes to the same file).
+  if (fi->flags & O_DIRECT) {
+    fi->direct_io = 1;
+    fi->parallel_direct_writes = 1;
+  }
+  */
+
+  fi->fh = fd;
+  return 0;
+}
+
+/* Complete copy of the example method(no need to modify anything so far) */
+static int xmp_read(const char *path, char *buf, size_t size, off_t offset,
+                    struct fuse_file_info *fi) {
+  int res;
+
+  (void)path;
+  res = pread(fi->fh, buf, size, offset);
+  if (res == -1)
+    res = -errno;
+
+  return res;
+}
+
+/* Complete copy of the example method(no need to modify anything so far) */
+static int xmp_read_buf(const char *path, struct fuse_bufvec **bufp,
+                        size_t size, off_t offset, struct fuse_file_info *fi) {
+  struct fuse_bufvec *src;
+
+  (void)path;
+
+  src = malloc(sizeof(struct fuse_bufvec));
+  if (src == NULL)
+    return -ENOMEM;
+
+  *src = FUSE_BUFVEC_INIT(size);
+
+  src->buf[0].flags = FUSE_BUF_IS_FD | FUSE_BUF_FD_SEEK;
+  src->buf[0].fd = fi->fh;
+  src->buf[0].pos = offset;
+
+  *bufp = src;
+
+  return 0;
+}
+
+/* Complete copy of the example method(no need to modify anything so far) */
+static int xmp_write(const char *path, const char *buf, size_t size,
+                     off_t offset, struct fuse_file_info *fi) {
+  int res;
+
+  (void)path;
+  res = pwrite(fi->fh, buf, size, offset);
+  if (res == -1)
+    res = -errno;
+
+  return res;
+}
+
+/* Complete copy of the example method(no need to modify anything so far) */
+static int xmp_write_buf(const char *path, struct fuse_bufvec *buf,
+                         off_t offset, struct fuse_file_info *fi) {
+  struct fuse_bufvec dst = FUSE_BUFVEC_INIT(fuse_buf_size(buf));
+
+  (void)path;
+
+  dst.buf[0].flags = FUSE_BUF_IS_FD | FUSE_BUF_FD_SEEK;
+  dst.buf[0].fd = fi->fh;
+  dst.buf[0].pos = offset;
+
+  return fuse_buf_copy(&dst, buf, FUSE_BUF_SPLICE_NONBLOCK);
+}
+
+static int xmp_statfs(const char *path, struct statvfs *stbuf) {
+  int res;
+
+  res = statvfs(path, stbuf);
+  if (res == -1)
+    return -errno;
+
+  return 0;
+}
+
+/* Complete copy of the example method(no need to modify anything so far) */
+static int xmp_flush(const char *path, struct fuse_file_info *fi) {
+  int res;
+
+  (void)path;
+  /* This is called from every close on an open file, so call the
+     close on the underlying filesystem.	But since flush may be
+     called multiple times for an open file, this must not really
+     close the file.  This is important if used on a network
+     filesystem like NFS which flush the data/metadata on close() */
+  res = close(dup(fi->fh));
+  if (res == -1)
+    return -errno;
+
+  return 0;
+}
+
+/* Complete copy of the example method(no need to modify anything so far) */
+static int xmp_release(const char *path, struct fuse_file_info *fi) {
+  (void)path;
+  close(fi->fh);
+
+  return 0;
+}
+
+/* Complete copy of the example method(no need to modify anything so far) */
+static int xmp_fsync(const char *path, int isdatasync,
+                     struct fuse_file_info *fi) {
+  int res;
+  (void)path;
+
+#ifndef HAVE_FDATASYNC
+  (void)isdatasync;
+#else
+  if (isdatasync)
+    res = fdatasync(fi->fh);
+  else
+#endif
+  res = fsync(fi->fh);
+  if (res == -1)
+    return -errno;
+
+  return 0;
+}
+
+#ifdef HAVE_POSIX_FALLOCATE
+static int xmp_fallocate(const char *path, int mode, off_t offset, off_t length,
+                         struct fuse_file_info *fi) {
+  (void)path;
+
+  if (mode)
+    return -EOPNOTSUPP;
+
+  return -posix_fallocate(fi->fh, offset, length);
+}
+#endif
+
+#ifdef HAVE_SETXATTR
+/* xattr operations are optional and can safely be left unimplemented */
+static int xmp_setxattr(const char *path, const char *name, const char *value,
+                        size_t size, int flags) {
+  int res = lsetxattr(path, name, value, size, flags);
+  if (res == -1)
+    return -errno;
+  return 0;
+}
+
+static int xmp_getxattr(const char *path, const char *name, char *value,
+                        size_t size) {
+  int res = lgetxattr(path, name, value, size);
+  if (res == -1)
+    return -errno;
+  return res;
+}
+
+static int xmp_listxattr(const char *path, char *list, size_t size) {
+  int res = llistxattr(path, list, size);
+  if (res == -1)
+    return -errno;
+  return res;
+}
+
+static int xmp_removexattr(const char *path, const char *name) {
+  int res = lremovexattr(path, name);
+  if (res == -1)
+    return -errno;
+  return 0;
+}
+#endif /* HAVE_SETXATTR */
+
+#ifdef HAVE_LIBULOCKMGR
+static int xmp_lock(const char *path, struct fuse_file_info *fi, int cmd,
+                    struct flock *lock) {
+  (void)path;
+
+  return ulockmgr_op(fi->fh, cmd, lock, &fi->lock_owner,
+                     sizeof(fi->lock_owner));
+}
+#endif
+
+/* Complete copy of the example method(no need to modify anything so far) */
+static int xmp_flock(const char *path, struct fuse_file_info *fi, int op) {
+  int res;
+  (void)path;
+
+  res = flock(fi->fh, op);
+  if (res == -1)
+    return -errno;
+
+  return 0;
+}
+
+#ifdef HAVE_COPY_FILE_RANGE
+static ssize_t xmp_copy_file_range(const char *path_in,
+                                   struct fuse_file_info *fi_in, off_t off_in,
+                                   const char *path_out,
+                                   struct fuse_file_info *fi_out, off_t off_out,
+                                   size_t len, int flags) {
+  ssize_t res;
+  (void)path_in;
+  (void)path_out;
+
+  res = copy_file_range(fi_in->fh, &off_in, fi_out->fh, &off_out, len, flags);
+  if (res == -1)
+    return -errno;
+
+  return res;
+}
+#endif
+
+/* Complete copy of the example method(no need to modify anything so far) */
+static off_t xmp_lseek(const char *path, off_t off, int whence,
+                       struct fuse_file_info *fi) {
+  off_t res;
+  (void)path;
+
+  res = lseek(fi->fh, off, whence);
+  if (res == -1)
+    return -errno;
+
+  return res;
+}
+
+// TODO: look trough "optional"(commented out) operations.
+static const struct fuse_operations xmp_oper = {
+    .init = xmp_init,
+    .getattr = xmp_getattr,
+    .access = xmp_access,
+    .readlink = xmp_readlink,
+    .opendir = xmp_opendir,
+    .readdir = xmp_readdir,
+    .releasedir = xmp_releasedir,
+    //    .mknod = xmp_mknod,
+    .mkdir = xmp_mkdir,
+    .symlink = xmp_symlink,
+    .unlink = xmp_unlink,
+    .rmdir = xmp_rmdir,
+    .rename = xmp_rename,
+    .link = xmp_link,
+    .chmod = xmp_chmod,
+    .chown = xmp_chown,
+    .truncate = xmp_truncate,
+#ifdef HAVE_UTIMENSAT
+    .utimens = xmp_utimens,
+#endif
+    .create = xmp_create,
+    .open = xmp_open,
+    .read = xmp_read,
+    .read_buf = xmp_read_buf,
+    .write = xmp_write,
+    .write_buf = xmp_write_buf,
+    .statfs = xmp_statfs,
+    .flush = xmp_flush,
+    .release = xmp_release,
+    .fsync = xmp_fsync,
+#ifdef HAVE_POSIX_FALLOCATE
+// .fallocate = xmp_fallocate,
+#endif
+#ifdef HAVE_SETXATTR
+// .setxattr = xmp_setxattr,
+// .getxattr = xmp_getxattr,
+// .listxattr = xmp_listxattr,
+// .removexattr = xmp_removexattr,
+#endif
+#ifdef HAVE_LIBULOCKMGR
+// .lock = xmp_lock,
+#endif
+    .flock = xmp_flock,
+#ifdef HAVE_COPY_FILE_RANGE
+// .copy_file_range = xmp_copy_file_range,
+#endif
+    .lseek = xmp_lseek,
+};
+
+const struct fuse_operations *get_fuse_operations() { return &xmp_oper; }

src/fuse_operations.h

@@ -0,0 +1,26 @@
+/*
+  ICFS: Interactively Controlled File System
+  Copyright (C) 2024-2025  Fedir Kovalov
+
+  This program can be distributed under the terms of the GNU GPLv2.
+  See the file LICENSE.
+*/
+
+#ifndef FUSE_OPERATIONS
+#define FUSE_OPERATIONS
+
+#define FUSE_USE_VERSION 31
+
+#include <fuse3/fuse.h>
+
+const struct fuse_operations *get_fuse_operations();
+
+/*
+ * Sets the default permission granted by file creation.
+ *
+ * @param val: the default permission to grant. Should be one of GRANT_TEMP,
+ * GRANT_TEM and 0. When set to 0, grants no permissions.
+ */
+void set_auto_create_perm(int val);
+
+#endif

src/gui/Makefile

@@ -0,0 +1,77 @@
+SHELL=/bin/bash
+
+# configurable options
+
+ifndef ($(SOURCES_DIR))
+	SOURCES_DIR := .
+endif
+
+ifndef ($(TESTS_DIR))
+	TESTS_DIR := .
+endif
+
+ifndef ($(BUILD_DIR))
+	BUILD_DIR := .
+endif
+
+CC := gcc
+CXX := g++
+
+
+# dependencies
+
+PACKAGE_NAMES := gtk4 libadwaita-1
+
+ifeq ($(TEST), 1)
+	#	PACKAGE_NAMES += check # TODO: use check?
+endif
+
+
+# set up cflags and libs
+
+CFLAGS := -D_FILE_OFFSET_BITS=64
+LDFLAGS :=
+
+CFLAGS += $(shell pkg-config --cflags $(PACKAGE_NAMES))
+LDFLAGS += $(shell pkg-config --libs $(PACKAGE_NAMES))
+
+ifeq ($(DEBUG),1)
+	CFLAGS += -O0 -pedantic -g -Wall -Wextra -Wcast-align \
+						-Wcast-qual -Wdisabled-optimization -Wformat=2 \
+						-Winit-self -Wlogical-op -Wmissing-declarations \
+						-Wmissing-include-dirs -Wredundant-decls -Wshadow \
+						-Wsign-conversion -Wstrict-overflow=5 \
+						-Wswitch-default -Wundef -Wno-unused
+	LDFLAGS += 
+else
+	CFLAGS += -O3
+	LDFLAGS +=
+endif
+
+
+# set up targets 
+
+TARGETS := $(BUILD_DIR)/icfs_dialogue
+
+ifeq ($(TEST), 1)
+	TARGETS += icfs_dialogue_test
+endif
+
+
+# build!
+
+default: $(TARGETS)
+
+.PHONY: clean icfs_dialogue_test
+
+icfs_dialogue_test: $(BUILD_DIR)/icfs_dialogue
+	$(BUILD_DIR)/icfs_dialogue 666 cat /home/fedir /Downloads
+
+$(BUILD_DIR)/icfs_dialogue: $(BUILD_DIR)/icfs_dialogue.o
+	$(CC) $(CFLAGS) $^ $(LDFLAGS) -o $(BUILD_DIR)/icfs_dialogue
+
+$(BUILD_DIR)/icfs_dialogue.o: $(SOURCES_DIR)/icfs_dialogue.c
+	$(CC) $(CFLAGS) -c $< $(LDFLAGS) -o $(BUILD_DIR)/icfs_dialogue.o
+
+clean:
+	rm $(BUILD_DIR)/*.o $(BUILD_DIR)/icfs_dialogue

src/gui/icfs_dialogue.c

@@ -0,0 +1,169 @@
+#include "gio/gio.h"
+#include "glib-object.h"
+#include "glib.h"
+#include <adwaita.h>
+#include <gtk/gtk.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define YES 1
+#define NO 0
+#define PERM 2
+#define TEMP 0
+
+int exit_code = 0;
+gboolean is_permanent = false;
+GtkEntryBuffer *entry_buffer = NULL;
+GtkWidget *checkbox = NULL;
+
+static void positive_response(GtkWindow *window) {
+  fprintf(stdout, "%s", gtk_entry_buffer_get_text(entry_buffer));
+  exit_code = (gtk_check_button_get_active(GTK_CHECK_BUTTON(checkbox)))
+                  ? YES | PERM
+                  : YES | TEMP;
+  gtk_window_close(window);
+}
+
+static void negative_response(GtkWindow *window) {
+  fprintf(stdout, "%s", gtk_entry_buffer_get_text(entry_buffer));
+  exit_code = (gtk_check_button_get_active(GTK_CHECK_BUTTON(checkbox)))
+                  ? NO | PERM
+                  : NO | TEMP;
+  gtk_window_close(window);
+}
+
+static void on_check_button_toggled(GtkToggleButton *button,
+                                    gpointer user_data) {
+  gboolean active = gtk_toggle_button_get_active(button);
+}
+
+static void on_activate(GtkApplication *app, gpointer user_data) {
+  // Create the main window
+  AdwWindow *window = ADW_WINDOW(adw_window_new());
+  gtk_window_set_application(GTK_WINDOW(window), app);
+  gtk_window_set_title(GTK_WINDOW(window), "icfs");
+  // gtk_window_set_default_size(GTK_WINDOW(window), 300, 150);
+
+  AdwStatusPage *content = ADW_STATUS_PAGE(adw_status_page_new());
+  adw_status_page_set_title(content, "Allow access?");
+
+  char *description = NULL;
+  asprintf(
+      &description,
+      "Allow process <tt>%s</tt> with PID <tt>%s</tt> to access <tt>%s</tt>",
+      g_object_get_data(G_OBJECT(app), "accessing_name"),
+      g_object_get_data(G_OBJECT(app), "accessing_pid"),
+      g_object_get_data(G_OBJECT(app), "access_dir"));
+  adw_status_page_set_description(content, description);
+  free(description);
+
+  entry_buffer = gtk_entry_buffer_new(
+      g_object_get_data(G_OBJECT(app), "access_dir"),
+      strlen(g_object_get_data(G_OBJECT(app), "access_dir")));
+
+  GtkWidget *entry = gtk_entry_new();
+  gtk_entry_set_buffer(GTK_ENTRY(entry), entry_buffer);
+  gtk_entry_set_placeholder_text(GTK_ENTRY(entry), "Enter filename");
+  gtk_widget_set_hexpand(entry, TRUE);
+
+  // Create a prefix label and box
+  GtkWidget *entry_box = gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 0);
+  GtkWidget *prefix_label =
+      gtk_label_new(g_object_get_data(G_OBJECT(app), "root_folder"));
+  gtk_box_append(GTK_BOX(entry_box), prefix_label);
+  gtk_box_append(GTK_BOX(entry_box), entry);
+
+  checkbox = gtk_check_button_new_with_label("Permanent");
+  gtk_check_button_set_active(GTK_CHECK_BUTTON(checkbox), false);
+  // gtk_widget_set_halign(checkbox, GTK_ALIGN_CENTER);
+
+  GtkWidget *yes_button = gtk_button_new_with_label("Yes");
+  gtk_widget_set_hexpand(yes_button, TRUE);
+  g_signal_connect_swapped(yes_button, "clicked", G_CALLBACK(positive_response),
+                           window);
+
+  GtkWidget *no_button = gtk_button_new_with_label("No");
+  gtk_widget_set_hexpand(no_button, TRUE);
+  g_signal_connect_swapped(no_button, "clicked", G_CALLBACK(negative_response),
+                           window);
+
+  GtkWidget *button_box = gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 6);
+  gtk_box_append(GTK_BOX(button_box), yes_button);
+  gtk_box_append(GTK_BOX(button_box), no_button);
+  gtk_widget_set_halign(button_box, GTK_ALIGN_FILL);
+
+  // Combine everything in a box
+  GtkWidget *box = gtk_box_new(GTK_ORIENTATION_VERTICAL, 12);
+  gtk_box_append(GTK_BOX(box), GTK_WIDGET(content));
+  gtk_box_append(GTK_BOX(box), entry_box);
+  gtk_box_append(GTK_BOX(box), checkbox);
+  gtk_box_append(GTK_BOX(box), button_box);
+  gtk_widget_set_margin_top(GTK_WIDGET(box), 12);
+  gtk_widget_set_margin_bottom(GTK_WIDGET(box), 12);
+  gtk_widget_set_margin_start(GTK_WIDGET(box), 12);
+  gtk_widget_set_margin_end(GTK_WIDGET(box), 12);
+
+  // g_signal_connect(window, "response", G_CALLBACK(gtk_window_close), window);
+
+  // Show the dialog
+  adw_window_set_content(window, box);
+  gtk_window_present(GTK_WINDOW(window));
+}
+
+static int on_command_line(GApplication *app, GApplicationCommandLine *cmdline,
+                           gpointer user_data) {
+  gchar **argv;
+  gint argc;
+
+  argv = g_application_command_line_get_arguments(cmdline, &argc);
+
+  // Handle your arguments here
+  if (argc >= 5) {
+    fprintf(stderr, "%s\n", argv[1]);
+    g_object_set_data_full(G_OBJECT(app), "accessing_pid", g_strdup(argv[1]),
+                           g_free);
+    g_object_set_data_full(G_OBJECT(app), "accessing_name", g_strdup(argv[2]),
+                           g_free);
+    g_object_set_data_full(G_OBJECT(app), "root_folder", g_strdup(argv[3]),
+                           g_free);
+    g_object_set_data_full(G_OBJECT(app), "access_dir", g_strdup(argv[4]),
+                           g_free);
+  }
+
+  g_strfreev(argv);
+
+  // Activate the application
+  g_application_activate(app);
+  return 0;
+}
+
+int main(int argc, char **argv) {
+
+  if (argc == 2 && strcmp(argv[1], "--version") == 0) {
+    fprintf(stdout, "icfs_dialogue 1.0.0");
+    return 0;
+  }
+
+  if (argc != 5) {
+    fprintf(stdout, "Usage: icfs_dialogue [accessing pid] [accessing name] "
+                    "[root folder] [access dir]");
+    return 255;
+  }
+
+  // disable accessibility features to prevent attacks
+  g_setenv("NO_AT_BRIDGE", "1", TRUE);
+
+  // Create a new application
+  AdwApplication *app = adw_application_new("de.umbrasolis.icfs_dialogue",
+                                            G_APPLICATION_HANDLES_COMMAND_LINE);
+
+  g_signal_connect(app, "command-line", G_CALLBACK(on_command_line), NULL);
+  g_signal_connect(app, "activate", G_CALLBACK(on_activate), NULL);
+
+  // Run the application
+  int status = g_application_run(G_APPLICATION(app), argc, argv);
+  g_object_unref(app);
+
+  return (status == 0) ? exit_code : status;
+}

src/main.c

@@ -3,733 +3,91 @@
   Copyright (C) 2001-2007  Miklos Szeredi <miklos@szeredi.hu>
   Copyright (C) 2011       Sebastian Pipping <sebastian@pipping.org>
 
+  ICFS: Interactively Controlled File System
+  Copyright (C) 2024-2025  Fedir Kovalov
+
   This program can be distributed under the terms of the GNU GPLv2.
-  See the file COPYING.
+  See the file LICENSE.
 */
 
-/** @file
+#include <string.h>
- *
- * This file system mirrors the existing file system hierarchy of the
- * system, starting at the root file system. This is implemented by
- * just "passing through" all requests to the corresponding user-space
- * libc functions. This implementation is a little more sophisticated
- * than the one in passthrough.c, so performance is not quite as bad.
- *
- * Compile with:
- *
- *     gcc -Wall passthrough_fh.c `pkg-config fuse3 --cflags --libs` -lulockmgr
- * -o passthrough_fh
- *
- * ## Source code ##
- * \include passthrough_fh.c
- */
-
 #define FUSE_USE_VERSION 31
 
 #define _GNU_SOURCE
 
 #include <fuse3/fuse.h>
-
-#ifdef HAVE_LIBULOCKMGR
-#include <ulockmgr.h>
-#endif
-
-#include <dirent.h>
-#include <errno.h>
-#include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <string.h>
+#include <sys/types.h>
-#include <sys/stat.h>
-#include <sys/time.h>
 #include <unistd.h>
-#ifdef HAVE_SETXATTR
-#include <sys/xattr.h>
-#endif
-#include <sys/file.h> /* flock(2) */
 
+#include "fuse_operations.h"
 #include "sourcefs.h"
 #include "ui-socket.h"
 
 const char *mountpoint = NULL;
 
-static void *xmp_init(struct fuse_conn_info *conn, struct fuse_config *cfg) {
-  (void)conn;
-  cfg->use_ino = 1;
-  cfg->nullpath_ok = 1;
-
-  /* parallel_direct_writes feature depends on direct_io features.
-     To make parallel_direct_writes valid, need either set cfg->direct_io
-     in current function (recommended in high level API) or set fi->direct_io
-     in xmp_create() or xmp_open(). */
-  // cfg->direct_io = 1;
-  // cfg->parallel_direct_writes = 1;
-
-  /* Pick up changes from lower filesystem right away. This is
-     also necessary for better hardlink support. When the kernel
-     calls the unlink() handler, it does not know the inode of
-     the to-be-removed entry and can therefore not invalidate
-     the cache of the associated inode - resulting in an
-     incorrect st_nlink value being reported for any remaining
-     hardlinks to this inode. */
-  cfg->entry_timeout = 0;
-  cfg->attr_timeout = 0;
-  cfg->negative_timeout = 0;
-
-  return NULL;
-}
-
-static int xmp_getattr(const char *path, struct stat *stbuf,
-                       struct fuse_file_info *fi) {
-  int res;
-
-  (void)path;
-
-  if (fi)
-    res = fstat(fi->fh, stbuf);
-  else
-    res = source_stat(path, stbuf);
-  if (res == -1) {
-    perror("Stat failed");
-    return -errno;
-  }
-
-  return 0;
-}
-
-static int xmp_access(const char *path, int mask) {
-  int res;
-
-  res = access(path, mask);
-  if (res == -1)
-    return -errno;
-
-  return 0;
-}
-
-static int xmp_readlink(const char *path, char *buf, size_t size) {
-  int res;
-
-  res = readlink(path, buf, size - 1);
-  if (res == -1)
-    return -errno;
-
-  buf[res] = '\0';
-  return 0;
-}
-
-struct xmp_dirp {
-  DIR *dp;
-  struct dirent *entry;
-  off_t offset;
-};
-
-static int xmp_opendir(const char *path, struct fuse_file_info *fi) {
-  int res;
-  struct xmp_dirp *d = malloc(sizeof(struct xmp_dirp));
-  if (d == NULL)
-    return -ENOMEM;
-
-  d->dp = source_opendir(path);
-  if (d->dp == NULL) {
-    perror("Opendir failed");
-    res = -errno;
-    free(d);
-    return res;
-  }
-  d->offset = 0;
-  d->entry = NULL;
-
-  fi->fh = (unsigned long)d;
-  return 0;
-}
-
-static inline struct xmp_dirp *get_dirp(struct fuse_file_info *fi) {
-  return (struct xmp_dirp *)(uintptr_t)fi->fh;
-}
-
-/* Complete copy of the example method(no need to modify anything so far) */
-static int xmp_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
-                       off_t offset, struct fuse_file_info *fi,
-                       enum fuse_readdir_flags flags) {
-  struct xmp_dirp *d = get_dirp(fi);
-
-  (void)path;
-  if (offset != d->offset) {
-#ifndef __FreeBSD__
-    seekdir(d->dp, offset);
-#else
-    /* Subtract the one that we add when calling
-       telldir() below */
-    seekdir(d->dp, offset - 1);
-#endif
-    d->entry = NULL;
-    d->offset = offset;
-  }
-  while (1) {
-    struct stat st;
-    off_t nextoff;
-    // enum fuse_fill_dir_flags fill_flags = FUSE_FILL_DIR_DEFAULTS;
-    enum fuse_fill_dir_flags fill_flags = 0;
-
-    if (!d->entry) {
-      d->entry = readdir(d->dp);
-      if (!d->entry)
-        break;
-    }
-#ifdef HAVE_FSTATAT
-    if (flags & FUSE_READDIR_PLUS) {
-      int res;
-
-      res = fstatat(dirfd(d->dp), d->entry->d_name, &st, AT_SYMLINK_NOFOLLOW);
-      if (res != -1)
-        fill_flags |= FUSE_FILL_DIR_PLUS;
-    }
-#endif
-    if (!(fill_flags & FUSE_FILL_DIR_PLUS)) {
-      memset(&st, 0, sizeof(st));
-      st.st_ino = d->entry->d_ino;
-      st.st_mode = d->entry->d_type << 12;
-    }
-    nextoff = telldir(d->dp);
-#ifdef __FreeBSD__
-    /* Under FreeBSD, telldir() may return 0 the first time
-       it is called. But for libfuse, an offset of zero
-       means that offsets are not supported, so we shift
-       everything by one. */
-    nextoff++;
-#endif
-    if (filler(buf, d->entry->d_name, &st, nextoff, fill_flags))
-      break;
-
-    d->entry = NULL;
-    d->offset = nextoff;
-  }
-
-  return 0;
-}
-
-/* Complete copy of the example method(no need to modify anything so far) */
-static int xmp_releasedir(const char *path, struct fuse_file_info *fi) {
-  struct xmp_dirp *d = get_dirp(fi);
-  (void)path;
-  closedir(d->dp);
-  free(d);
-  return 0;
-}
-
-/*
-// TODO: make this work
-static int xmp_mknod(const char *path, mode_t mode, dev_t rdev) {
-  int res;
-
-  if (S_ISFIFO(mode))
-    res = mkfifo(path, mode);
-  else
-    res = mknod(path, mode, rdev);
-  if (res == -1)
-    return -errno;
-
-  return 0;
-}
-*/
-
-static int xmp_mkdir(const char *path, mode_t mode) {
-  int res;
-
-  res = source_mkdir(path, mode);
-  if (res == -1)
-    return -errno;
-
-  return 0;
-}
-
-static int xmp_unlink(const char *path) {
-  int res;
-
-  res = source_unlink(path);
-  if (res == -1)
-    return -errno;
-
-  return 0;
-}
-
-static int xmp_rmdir(const char *path) {
-  int res;
-
-  res = source_rmdir(path);
-  if (res == -1)
-    return -errno;
-
-  return 0;
-}
-
-static int xmp_symlink(const char *from, const char *to) {
-  int res;
-
-  res = source_symlink(from, to);
-  if (res == -1)
-    return -errno;
-
-  return 0;
-}
-
-static int xmp_rename(const char *from, const char *to, unsigned int flags) {
-  int res;
-
-  /* When we have renameat2() in libc, then we can implement flags */
-  if (flags)
-    return -EINVAL;
-
-  res = source_rename(from, to);
-  if (res == -1)
-    return -errno;
-
-  return 0;
-}
-
-static int xmp_link(const char *from, const char *to) {
-  int res;
-
-  res = source_link(from, to);
-  if (res == -1)
-    return -errno;
-
-  return 0;
-}
-
-static int xmp_chmod(const char *path, mode_t mode, struct fuse_file_info *fi) {
-  int res;
-
-  if (fi)
-    res = fchmod(fi->fh, mode);
-  else
-    res = source_chmod(path, mode);
-  if (res == -1)
-    return -errno;
-
-  return 0;
-}
-
-static int xmp_chown(const char *path, uid_t uid, gid_t gid,
-                     struct fuse_file_info *fi) {
-  int res;
-
-  if (fi)
-    res = fchown(fi->fh, uid, gid);
-  else
-    res = source_chown(path, uid, gid);
-  if (res == -1)
-    return -errno;
-
-  return 0;
-}
-
-static int xmp_truncate(const char *path, off_t size,
-                        struct fuse_file_info *fi) {
-  int res;
-
-  if (fi)
-    res = ftruncate(fi->fh, size);
-  else
-    res = source_truncate(path, size);
-
-  if (res == -1)
-    return -errno;
-
-  return 0;
-}
-
-#ifdef HAVE_UTIMENSAT
-static int xmp_utimens(const char *path, const struct timespec ts[2],
-                       struct fuse_file_info *fi) {
-  int res;
-
-  /* don't use utime/utimes since they follow symlinks */
-  if (fi)
-    res = futimens(fi->fh, ts);
-  else
-    res = utimensat(0, path, ts, AT_SYMLINK_NOFOLLOW);
-  if (res == -1)
-    return -errno;
-
-  return 0;
-}
-#endif
-
-// TODO: move this to other file
-const char *get_process_name_by_pid(const int pid) {
-  char *name = (char *)calloc(1024, sizeof(char));
-  if (name) {
-    sprintf(name, "/proc/%d/cmdline", pid);
-    FILE *f = fopen(name, "r");
-    if (f) {
-      size_t size;
-      size = fread(name, sizeof(char), 1024, f);
-      if (size > 0) {
-        if ('\n' == name[size - 1])
-          name[size - 1] = '\0';
-      }
-      fclose(f);
-    }
-  }
-  return name;
-}
-
-// TODO: move this somewhere else
-const char *real_filename(const char *filename) { return filename; }
-
-static int xmp_create(const char *path, mode_t mode,
-                      struct fuse_file_info *fi) {
-  int fd;
-
-  struct process_info pi;
-
-  struct fuse_context *fc = fuse_get_context();
-
-  pi.PID = fc->pid;
-  pi.UID = fc->uid;
-  pi.name = get_process_name_by_pid(pi.PID);
-
-  // fprintf(stderr, "%s, %d\n", path, ask_access(path, pi));
-
-  if (ask_access(real_filename(path), pi)) {
-    free(pi.name);
-    return -EACCES;
-  }
-
-  free(pi.name);
-
-  fd = source_create(path, fi->flags, mode);
-  if (fd == -1)
-    return -errno;
-
-  fi->fh = fd;
-  return 0;
-}
-
-static int xmp_open(const char *path, struct fuse_file_info *fi) {
-  int fd;
-
-  struct process_info pi;
-
-  struct fuse_context *fc = fuse_get_context();
-
-  pi.PID = fc->pid;
-  pi.UID = fc->uid;
-  pi.name = get_process_name_by_pid(pi.PID);
-
-  // fprintf(stderr, "%s, %d\n", path, ask_access(path, pi));
-  if (ask_access(real_filename(path), pi)) {
-    free(pi.name);
-    return -EACCES;
-  }
-
-  free(pi.name);
-
-  fd = source_open(path, fi->flags);
-  if (fd == -1)
-    return -errno;
-
-  /* Enable direct_io when open has flags O_DIRECT to enjoy the feature
-     parallel_direct_writes (i.e., to get a shared lock, not exclusive lock,
-     for writes to the same file).
-  if (fi->flags & O_DIRECT) {
-    fi->direct_io = 1;
-    fi->parallel_direct_writes = 1;
-  }
-  */
-
-  fi->fh = fd;
-  return 0;
-}
-
-/* Complete copy of the example method(no need to modify anything so far) */
-static int xmp_read(const char *path, char *buf, size_t size, off_t offset,
-                    struct fuse_file_info *fi) {
-  int res;
-
-  (void)path;
-  res = pread(fi->fh, buf, size, offset);
-  if (res == -1)
-    res = -errno;
-
-  return res;
-}
-
-/* Complete copy of the example method(no need to modify anything so far) */
-static int xmp_read_buf(const char *path, struct fuse_bufvec **bufp,
-                        size_t size, off_t offset, struct fuse_file_info *fi) {
-  struct fuse_bufvec *src;
-
-  (void)path;
-
-  src = malloc(sizeof(struct fuse_bufvec));
-  if (src == NULL)
-    return -ENOMEM;
-
-  *src = FUSE_BUFVEC_INIT(size);
-
-  src->buf[0].flags = FUSE_BUF_IS_FD | FUSE_BUF_FD_SEEK;
-  src->buf[0].fd = fi->fh;
-  src->buf[0].pos = offset;
-
-  *bufp = src;
-
-  return 0;
-}
-
-/* Complete copy of the example method(no need to modify anything so far) */
-static int xmp_write(const char *path, const char *buf, size_t size,
-                     off_t offset, struct fuse_file_info *fi) {
-  int res;
-
-  (void)path;
-  res = pwrite(fi->fh, buf, size, offset);
-  if (res == -1)
-    res = -errno;
-
-  return res;
-}
-
-/* Complete copy of the example method(no need to modify anything so far) */
-static int xmp_write_buf(const char *path, struct fuse_bufvec *buf,
-                         off_t offset, struct fuse_file_info *fi) {
-  struct fuse_bufvec dst = FUSE_BUFVEC_INIT(fuse_buf_size(buf));
-
-  (void)path;
-
-  dst.buf[0].flags = FUSE_BUF_IS_FD | FUSE_BUF_FD_SEEK;
-  dst.buf[0].fd = fi->fh;
-  dst.buf[0].pos = offset;
-
-  return fuse_buf_copy(&dst, buf, FUSE_BUF_SPLICE_NONBLOCK);
-}
-
-static int xmp_statfs(const char *path, struct statvfs *stbuf) {
-  int res;
-
-  res = statvfs(path, stbuf);
-  if (res == -1)
-    return -errno;
-
-  return 0;
-}
-
-/* Complete copy of the example method(no need to modify anything so far) */
-static int xmp_flush(const char *path, struct fuse_file_info *fi) {
-  int res;
-
-  (void)path;
-  /* This is called from every close on an open file, so call the
-     close on the underlying filesystem.	But since flush may be
-     called multiple times for an open file, this must not really
-     close the file.  This is important if used on a network
-     filesystem like NFS which flush the data/metadata on close() */
-  res = close(dup(fi->fh));
-  if (res == -1)
-    return -errno;
-
-  return 0;
-}
-
-/* Complete copy of the example method(no need to modify anything so far) */
-static int xmp_release(const char *path, struct fuse_file_info *fi) {
-  (void)path;
-  close(fi->fh);
-
-  return 0;
-}
-
-/* Complete copy of the example method(no need to modify anything so far) */
-static int xmp_fsync(const char *path, int isdatasync,
-                     struct fuse_file_info *fi) {
-  int res;
-  (void)path;
-
-#ifndef HAVE_FDATASYNC
-  (void)isdatasync;
-#else
-  if (isdatasync)
-    res = fdatasync(fi->fh);
-  else
-#endif
-  res = fsync(fi->fh);
-  if (res == -1)
-    return -errno;
-
-  return 0;
-}
-
-#ifdef HAVE_POSIX_FALLOCATE
-static int xmp_fallocate(const char *path, int mode, off_t offset, off_t length,
-                         struct fuse_file_info *fi) {
-  (void)path;
-
-  if (mode)
-    return -EOPNOTSUPP;
-
-  return -posix_fallocate(fi->fh, offset, length);
-}
-#endif
-
-#ifdef HAVE_SETXATTR
-/* xattr operations are optional and can safely be left unimplemented */
-static int xmp_setxattr(const char *path, const char *name, const char *value,
-                        size_t size, int flags) {
-  int res = lsetxattr(path, name, value, size, flags);
-  if (res == -1)
-    return -errno;
-  return 0;
-}
-
-static int xmp_getxattr(const char *path, const char *name, char *value,
-                        size_t size) {
-  int res = lgetxattr(path, name, value, size);
-  if (res == -1)
-    return -errno;
-  return res;
-}
-
-static int xmp_listxattr(const char *path, char *list, size_t size) {
-  int res = llistxattr(path, list, size);
-  if (res == -1)
-    return -errno;
-  return res;
-}
-
-static int xmp_removexattr(const char *path, const char *name) {
-  int res = lremovexattr(path, name);
-  if (res == -1)
-    return -errno;
-  return 0;
-}
-#endif /* HAVE_SETXATTR */
-
-#ifdef HAVE_LIBULOCKMGR
-static int xmp_lock(const char *path, struct fuse_file_info *fi, int cmd,
-                    struct flock *lock) {
-  (void)path;
-
-  return ulockmgr_op(fi->fh, cmd, lock, &fi->lock_owner,
-                     sizeof(fi->lock_owner));
-}
-#endif
-
-/* Complete copy of the example method(no need to modify anything so far) */
-static int xmp_flock(const char *path, struct fuse_file_info *fi, int op) {
-  int res;
-  (void)path;
-
-  res = flock(fi->fh, op);
-  if (res == -1)
-    return -errno;
-
-  return 0;
-}
-
-#ifdef HAVE_COPY_FILE_RANGE
-static ssize_t xmp_copy_file_range(const char *path_in,
-                                   struct fuse_file_info *fi_in, off_t off_in,
-                                   const char *path_out,
-                                   struct fuse_file_info *fi_out, off_t off_out,
-                                   size_t len, int flags) {
-  ssize_t res;
-  (void)path_in;
-  (void)path_out;
-
-  res = copy_file_range(fi_in->fh, &off_in, fi_out->fh, &off_out, len, flags);
-  if (res == -1)
-    return -errno;
-
-  return res;
-}
-#endif
-
-/* Complete copy of the example method(no need to modify anything so far) */
-static off_t xmp_lseek(const char *path, off_t off, int whence,
-                       struct fuse_file_info *fi) {
-  off_t res;
-  (void)path;
-
-  res = lseek(fi->fh, off, whence);
-  if (res == -1)
-    return -errno;
-
-  return res;
-}
-
-// TODO: look trough "optional"(commented out) operations.
-static const struct fuse_operations xmp_oper = {
-    .init = xmp_init,
-    .getattr = xmp_getattr,
-    // .access = xmp_access,
-    .readlink = xmp_readlink,
-    .opendir = xmp_opendir,
-    .readdir = xmp_readdir,
-    .releasedir = xmp_releasedir,
-    //    .mknod = xmp_mknod,
-    .mkdir = xmp_mkdir,
-    .symlink = xmp_symlink,
-    .unlink = xmp_unlink,
-    .rmdir = xmp_rmdir,
-    .rename = xmp_rename,
-    .link = xmp_link,
-    .chmod = xmp_chmod,
-    .chown = xmp_chown,
-    .truncate = xmp_truncate,
-#ifdef HAVE_UTIMENSAT
-// .utimens = xmp_utimens,
-#endif
-    .create = xmp_create,
-    .open = xmp_open,
-    .read = xmp_read,
-    .read_buf = xmp_read_buf,
-    .write = xmp_write,
-    .write_buf = xmp_write_buf,
-    .statfs = xmp_statfs,
-    .flush = xmp_flush,
-    .release = xmp_release,
-    .fsync = xmp_fsync,
-#ifdef HAVE_POSIX_FALLOCATE
-// .fallocate = xmp_fallocate,
-#endif
-#ifdef HAVE_SETXATTR
-// .setxattr = xmp_setxattr,
-// .getxattr = xmp_getxattr,
-// .listxattr = xmp_listxattr,
-// .removexattr = xmp_removexattr,
-#endif
-#ifdef HAVE_LIBULOCKMGR
-// .lock = xmp_lock,
-#endif
-    .flock = xmp_flock,
-#ifdef HAVE_COPY_FILE_RANGE
-// .copy_file_range = xmp_copy_file_range,
-#endif
-    .lseek = xmp_lseek,
-};
-
 int main(int argc, char *argv[]) {
+  if (argc < 3) {
+    fprintf(stderr, "Usage: icfs <FUSE arguments> [target directory] [path to "
+                    "the permanent permissions database] <ICFS "
+                    "arguments>\n\t--no-grant-on-create - do not give any "
+                    "access permissions on file creation"
+                    "(incompatible with --perm-on-create)\n\t--perm-on-create "
+                    "- automatically give permanent access permission to files "
+                    "a process creates "
+                    "(incompatible with --no-grant-on-create)\n");
+    return EXIT_FAILURE;
+  }
+
+  if ((0 == strcmp(argv[argc - 1], "--no-grant-on-create") &&
+       0 == strcmp(argv[argc - 2], "--temp-on-create")) ||
+      (0 == strcmp(argv[argc - 2], "--no-grant-on-create") &&
+       0 == strcmp(argv[argc - 1], "--temp-on-create"))) {
+    fprintf(stderr, "Usage: icfs <FUSE arguments> [target directory] [path to "
+                    "the permanent permissions database] <ICFS "
+                    "arguments>\n\t--no-grant-on-create - do not give any "
+                    "access permissions on file creation"
+                    "(incompatible with --perm-on-create)\n\t--perm-on-create "
+                    "- automatically give permanent access permission to files "
+                    "a process creates "
+                    "(incompatible with --no-grant-on-create)\n");
+    return EXIT_FAILURE;
+  }
+
+  // if umask != 0, the filesystem will create files with more restrictive
+  // permissions than it's caller reqested
   umask(0);
 
-  // FUSE won't tell us the mountpoint on it's own, so we need to extract it
+  if (0 == strcmp(argv[argc - 1], "--no-grant-on-create")) {
-  // ourselves.
+    set_auto_create_perm(0);
-  mountpoint = realpath(argv[argc - 1], NULL);
+    argc--;
+  }
+  if (0 == strcmp(argv[argc - 1], "--perm-on-create")) {
+    set_auto_create_perm(GRANT_PERM);
+    argc--;
+  }
 
-  int ret = source_init(mountpoint);
+  // ui socket should always be initialized before anything else, since it
+  // handles the setuid bits!
+  int ret = init_ui_socket(argv[argc - 1]);
   if (ret != 0) {
-    perror("source_init");
+    fprintf(stderr, "[ICFS] Could not initalize ui-socket.\n");
     exit(EXIT_FAILURE);
   }
 
-  ret = init_ui_socket("/home/fedir/.icfs-sock");
+  mountpoint = realpath(argv[argc - 2], NULL);
+
+  ret = source_init(mountpoint);
   if (ret != 0) {
-    perror("init_ui_socket");
+    perror("[ICFS] source_init");
     exit(EXIT_FAILURE);
   }
 
-  ret = fuse_main(argc, argv, &xmp_oper, NULL);
+  ret = fuse_main(argc - 1, argv, get_fuse_operations(), NULL);
-  free(mountpoint);
+
+  free((void *)mountpoint);
+  source_destroy();
+  destroy_ui_socket();
   return ret;
 }

src/perm_permissions_table.c

@@ -0,0 +1,301 @@
+/*
+  ICFS: Interactively Controlled File System
+  Copyright (C) 2024-2025  Fedir Kovalov
+
+  This program can be distributed under the terms of the GNU GPLv2.
+  See the file LICENSE.
+*/
+
+#include "perm_permissions_table.h"
+#include "access_t.h"
+#include "proc_operations.h"
+#include "process_info.h"
+#include "set_mode_t.h"
+#include <fcntl.h>
+#include <pthread.h>
+#include <sqlite3.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/fsuid.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+// Global pointer to the SQLite database storing permanent permissions
+sqlite3 *perm_database = NULL;
+const char *const table_name = "permissions";
+// Each row represents a permission to access a specific file for an executable
+const int column_count = 3;
+// Column names in the permissions table
+const char *const schema[] = {"executable", "filename", "mode"};
+// Expected SQL data types for each column
+const char *const types[] = {"TEXT", "TEXT", "INTEGER"};
+uid_t ruid, euid, current_uid;
+
+/**
+ * Callback to validate the database schema matches expectations.
+ * Verifies column order, names, and types during schema checks.
+ *
+ * @param unused: Ignored context pointer
+ * @param argc: Number of columns returned (should be 3)
+ * @param argv: Column data: index 0=name, 1=type, 2=notnull flag
+ * @param colname: Column names (unused)
+ * @return 0 on success, 1 if schema mismatch
+ */
+static int check_table_col_schema(void *notused, int argc, char **argv,
+                                  char **colname) {
+  (void)notused;
+  (void)colname;
+  if (argc < 3) {
+    fprintf(stderr,
+            "[ICFS] Unexpected amount of arguments given to the callback.\n");
+    return 1;
+  }
+  int column_num = atoi(argv[0]);
+  if (column_num >= column_count) {
+    fprintf(stderr, "[ICFS] Table contains unexpected amount of columns.\n");
+    return 1;
+  }
+
+  if (strcmp(schema[column_num], argv[1]) == 0 &&
+      strcmp(types[column_num], argv[2]) == 0) {
+    return 0;
+  }
+  fprintf(stderr, "[ICFS] Column %d does not conform to the schema.\n",
+          column_num);
+  return 1;
+}
+
+/**
+ * Creates the permissions table schema in the database.
+ * Called when the table doesn't exist yet.
+ *
+ * @return 0 on success, 1 on failure
+ */
+int create_database_schema(void) {
+  fprintf(stderr, "[ICFS] Creating table 'permissions'.\n");
+  const char *create_query =
+      "CREATE TABLE permissions(executable TEXT NOT "
+      "NULL, filename TEXT NOT NULL, mode INTEGER NOT NULL);";
+  char *err = NULL;
+  int ret = sqlite3_exec(perm_database, create_query, NULL, NULL, &err);
+
+  if (ret != SQLITE_OK) {
+    fprintf(stderr, "[ICFS] sqlite3 error: %s\n", err);
+    sqlite3_free(err);
+    return 1;
+  }
+
+  fprintf(stderr, "[ICFS] Database created successfully\n");
+  return 0;
+}
+
+/**
+ * Ensures the database schema matches expected structure.
+ * Validates table existence and column definitions.
+ *
+ * @return 0 if schema is valid, 1 if validation failed or repair failed
+ */
+int ensure_database_schema(void) {
+  // Check for the table.
+  int result = sqlite3_table_column_metadata(
+      perm_database, NULL, table_name, NULL, NULL, NULL, NULL, NULL, NULL);
+  if (result == SQLITE_ERROR) {
+    fprintf(stderr, "[ICFS] Table '%s' does not exist.\n", table_name);
+    if (create_database_schema()) {
+      fprintf(stderr, "[ICFS] Table could not be created.\n");
+      return 1;
+    }
+    return 0;
+  } else if (result != SQLITE_OK) {
+    fprintf(stderr, "[ICFS] Database metadata could not be retrieved.\n");
+    return 1;
+  }
+
+  // Verify column definitions
+  const char *pragma = "PRAGMA table_info(permissions);";
+  char *err = NULL;
+  int ret =
+      sqlite3_exec(perm_database, pragma, check_table_col_schema, NULL, &err);
+
+  if (ret != SQLITE_OK) {
+    fprintf(stderr, "[ICFS] sqlite3 error: %s\n", err);
+    sqlite3_free(err);
+    return 1;
+  }
+
+  fprintf(stderr, "[ICFS] Schema is correct.\n");
+  return 0;
+}
+
+/**
+ * Initializes the permanent permissions database.
+ * Creates/opens the database file and sets up schema.
+ *
+ * @param db_filename Path to the SQLite database file
+ * @return 0 on success, -1 on failure
+ */
+int init_perm_permissions_table(const char *db_filename) {
+  // Prevent group/others access during file creation
+  umask(0077);
+  ruid = getuid();
+  euid = geteuid();
+  fprintf(stderr, "[ICFS] Running with uid: %d, gid: %d\n", euid, getegid());
+
+  // Open database with read/write access and full mutex protection
+  if (sqlite3_open_v2(db_filename, &perm_database,
+                      SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE |
+                          SQLITE_OPEN_FULLMUTEX,
+                      NULL)) {
+    perror("[ICFS] Can't open permanent permissions database");
+    return -1;
+  }
+  umask(0); // Restore default umask
+
+  // Verify and initialize schema
+  if (ensure_database_schema()) {
+    fprintf(stderr, "[ICFS] Database schema is not correct.\n");
+    return -1;
+  }
+
+  // Switch to real UID, since we started with the icfs user to open the
+  // database
+  int status = seteuid(ruid);
+  if (status < 0) {
+    fprintf(stderr,
+            "[ICFS] Couldn't set euid to ruid during database setup.\n");
+    exit(status);
+  }
+
+  return 0;
+}
+
+/**
+ * Closes the database connection and releases resources.
+ * Should be called when the module is shutting down.
+ */
+void destroy_perm_permissions_table(void) { sqlite3_close(perm_database); }
+
+/**
+ * Checks if a specific process has permanent access to a file.
+ * Does not check parent processes.
+ *
+ * @param filename Path to the file being accessed
+ * @param pi Process information structure
+ * @return ALLOW (explicit allow), DENY (explicit deny), or NDEF (no info)
+ */
+access_t check_perm_access_noparent(const char *filename,
+                                    struct process_info pi) {
+  if (pi.name == NULL)
+    return NDEF;
+
+  access_t ret = NDEF;
+  sqlite3_stmt *stmt = NULL;
+
+  // Query checks:
+  // 1. Exact match for filename
+  // 2. Directory prefix match (filename starts with stored path + '/')
+  // Ordered by longest path for most specific match first
+  const char *sql =
+      "SELECT mode FROM permissions WHERE executable = ?1 "
+      "AND (( ?2 LIKE (filename || \'%\') AND filename "
+      "GLOB \'*/\') OR filename = ?2 ) ORDER BY LENGTH( filename ) DESC;";
+
+  sqlite3_prepare_v2(perm_database, sql, -1, &stmt, NULL);
+  sqlite3_bind_text(stmt, 1, pi.name, -1, SQLITE_STATIC);
+  sqlite3_bind_text(stmt, 2, filename, -1, SQLITE_STATIC);
+
+  int step_ret = sqlite3_step(stmt);
+  if (step_ret != SQLITE_ROW && step_ret != SQLITE_DONE) {
+    fprintf(stderr, "[ICFS] SQLite error: %s\n", sqlite3_errstr(step_ret));
+    sqlite3_finalize(stmt);
+    return ret;
+  }
+
+  if (step_ret == SQLITE_ROW) {
+    int mode_col = sqlite3_column_int(stmt, 0);
+    ret = mode_col ? ALLOW : DENY;
+  }
+
+  sqlite3_finalize(stmt);
+  return ret;
+}
+
+/**
+ * Checks if a process or any of its ancestors have permanent access.
+ * Handles hierarchical permission inheritance.
+ *
+ * @param filename Path to the file being accessed
+ * @param pi Process information structure
+ * @return ALLOW/DENY/NDEF with NDEF meaning no explicit rule found
+ * @note May return false negatives if parent processes terminate during check
+ */
+access_t check_perm_access(const char *filename, struct process_info pi) {
+  if (pi.PID == 0 || pi.name == NULL) {
+    return NDEF;
+  }
+
+  struct process_info current_pi = pi;
+  current_pi.name = strdup(current_pi.name);
+
+  while (current_pi.PID != 0) {
+    access_t access = check_perm_access_noparent(filename, current_pi);
+    free(current_pi.name);
+
+    if (access != NDEF) {
+      return access;
+    }
+
+    current_pi.name = NULL;
+    // Traverse to parent process
+    while (current_pi.name == NULL) {
+      current_pi.PID = get_main_thread_pid(get_parent_pid(current_pi.PID));
+      if (current_pi.PID != 0) {
+        current_pi.name = get_process_name_by_pid(current_pi.PID);
+      } else {
+        break;
+      }
+    }
+  }
+
+  return NDEF;
+}
+
+/**
+ * Sets a permanent access rule for a process-file combination.
+ *
+ * @param filename Path to the file needing access
+ * @param pi Process information
+ * @param mode Kind of access rule to be set - SET_DENY to deny access, and
+ * SET_ALLOW to allow access.
+ * @return 0 on success, 1 on failure
+ */
+int set_perm_access(const char *filename, struct process_info pi,
+                    set_mode_t mode) {
+  sqlite3_stmt *stmt = NULL;
+  char *sql = NULL;
+
+  if (mode == SET_ALLOW) {
+    sql = "INSERT INTO permissions VALUES (?1, ?2, TRUE);";
+  } else if (mode == SET_DENY) {
+    sql = "INSERT INTO permissions VALUES (?1, ?2, FALSE);";
+  } else {
+    return 1; // Invalid mode
+  }
+
+  sqlite3_prepare_v2(perm_database, sql, -1, &stmt, NULL);
+  sqlite3_bind_text(stmt, 1, pi.name, -1, SQLITE_STATIC);
+  sqlite3_bind_text(stmt, 2, filename, -1, SQLITE_STATIC);
+
+  int step_ret = sqlite3_step(stmt);
+  if (step_ret != SQLITE_DONE) {
+    fprintf(stderr, "[ICFS] SQLite error: %s\n", sqlite3_errstr(step_ret));
+    sqlite3_finalize(stmt);
+    return 1;
+  }
+
+  sqlite3_finalize(stmt);
+  return 0;
+}

src/perm_permissions_table.h

@@ -0,0 +1,53 @@
+/*
+  ICFS: Interactively Controlled File System
+  Copyright (C) 2024-2025  Fedir Kovalov
+
+  This program can be distributed under the terms of the GNU GPLv2.
+  See the file LICENSE.
+*/
+
+#ifndef PERM_PERMISSION_TABLE_H
+#define PERM_PERMISSION_TABLE_H
+
+#include "access_t.h"
+#include "process_info.h"
+#include "set_mode_t.h"
+
+/**
+ * Initializes the permanent permissions database.
+ * Creates/opens the database file and sets up schema.
+ *
+ * @param db_filename Path to the SQLite database file
+ * @return 0 on success, -1 on failure
+ */
+int init_perm_permissions_table(const char *db_filename);
+
+/**
+ * Closes the database connection and releases resources.
+ * Should be called when the module is shutting down.
+ */
+void destroy_perm_permissions_table();
+
+/**
+ * Checks if a process or any of its ancestors have permanent access.
+ * Handles hierarchical permission inheritance.
+ *
+ * @param filename Path to the file being accessed
+ * @param pi Process information structure
+ * @return ALLOW/DENY/NDEF with NDEF meaning no explicit rule found
+ * @note May return false negatives if parent processes terminate during check
+ */
+access_t check_perm_access(const char *filename, struct process_info pi);
+
+/**
+ * Sets a permanent access rule for a process-file combination.
+ *
+ * @param filename Path to the file needing access
+ * @param pi Process information
+ * @param mode SET_ALLOW (whitelist) or SET_DENY (blacklist)
+ * @return 0 on success, 1 on failure
+ */
+int set_perm_access(const char *filename, struct process_info pi,
+                    set_mode_t mode);
+
+#endif // #ifdef PERM_PERMISSION_TABLE_H

src/proc_operations.c

@@ -0,0 +1,153 @@
+/*
+  ICFS: Interactively Controlled File System
+  Copyright (C) 2024-2025  Fedir Kovalov
+
+  This program can be distributed under the terms of the GNU GPLv2.
+  See the file LICENSE.
+*/
+#include "proc_operations.h"
+#include <linux/limits.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+/**
+ * @brief Returns the PID of the main thread (i.e., the process ID) of the
+ * process that the given thread ID (tid) belongs to.
+ *
+ * In Linux, threads within the same process share the same thread group ID
+ * (TGID), which is equal to the PID of the main thread. This function retrieves
+ * the TGID by parsing `/proc/<tid>/status`, effectively returning the main
+ * thread's PID.
+ *
+ * @param tid The thread ID (TID) of any thread in the process.
+ * @return pid_t The process ID (main thread's PID), or 0 on error (invalid tid
+ * or file read failure).
+ */
+pid_t get_main_thread_pid(pid_t tid) {
+  // Validate input
+  if (tid <= 0) {
+    // Invalid TID: TIDs are always positive in Linux
+    return 0;
+  }
+
+  char path[PATH_MAX];
+  snprintf(path, sizeof(path), "/proc/%d/status", tid);
+
+  FILE *fp = fopen(path, "r");
+  if (!fp) {
+    return 0; // Could not open the file
+  }
+
+  pid_t tgid = 0;
+  char line[256];
+
+  while (fgets(line, sizeof(line), fp)) {
+    if (sscanf(line, "Tgid: %d", &tgid) == 1) {
+      break;
+    }
+  }
+
+  fclose(fp);
+
+  // Debugging check: If the provided tid is not the main thread's tid,
+  // this logs a message but does not affect the return value.
+  // This is useful for detecting cases where non-main threads are being
+  // inspected.
+  if (tgid != tid) {
+    fprintf(stderr,
+            "[ICFS] The tid and and pid wasn't equal. tid:%d, pid:%d.\n", tid,
+            tgid);
+  }
+
+  return tgid;
+}
+
+/**
+ * @brief Retrieves the full path of the executable for a given process ID.
+ *
+ * This function reads the `/proc/<pid>/exe` symbolic link, which points to the
+ * executable file of the process. The returned string is dynamically allocated
+ * and must be freed by the caller.
+ *
+ * @param pid The process ID to query.
+ * @return char* Dynamically allocated string containing the executable path, or
+ * NULL on failure.
+ */
+char *get_process_name_by_pid(const int pid) {
+  char path[1024];
+  sprintf(path, "/proc/%d/exe", pid);
+
+  size_t size = 128;
+  char *name = malloc(size);
+  if (name == NULL) {
+    fprintf(stderr, "[ICFS] Could not get process name by pid %d", pid);
+    perror("");
+    return NULL;
+  }
+
+  while (1) {
+    ssize_t len = readlink(path, name, size);
+
+    if (len == -1) {
+      fprintf(stderr, "[ICFS] Could not get process name by pid %d", pid);
+      perror("");
+      free(name);
+      return NULL;
+    }
+
+    // If the buffer was too small, double its size and try again
+    if ((size_t)len >= size) {
+      size *= 2;
+      char *new_name = realloc(name, size);
+      if (!new_name) {
+        free(name);
+        return NULL;
+      }
+      name = new_name;
+    } else {
+      // readlink does not null-terminate, so we must do it manually
+      name[len] = '\0';
+      break;
+    }
+  }
+
+  return name;
+}
+
+/**
+ * @brief Finds the parent process ID of a given process.
+ *
+ * This function parses the `/proc/<pid>/status` file to extract the `PPid`
+ * field, which represents the parent process ID. This is useful for tracing
+ * process lineage.
+ *
+ * @param pid The process ID of the process to find the parent of.
+ * @return pid_t The parent process ID, or 0 if the parent could not be
+ * determined.
+ */
+pid_t get_parent_pid(pid_t pid) {
+  pid_t ppid = 0;
+  char path[256];
+  snprintf(path, sizeof(path), "/proc/%d/status",
+           pid); // Use %d for signed pid_t
+
+  FILE *file = fopen(path, "r");
+  if (file == NULL) {
+    perror("[ICFS] Failed to open /proc/<pid>/status");
+    return 0;
+  }
+
+  char line[256];
+  while (fgets(line, sizeof(line), file)) {
+    // The "PPid:" field in `/proc/<pid>/status` is followed by a tab character
+    if (sscanf(line, "PPid:\t%d", &ppid) == 1) {
+      fclose(file);
+      return ppid;
+    }
+  }
+
+  fclose(file);
+  return 0; // Parent PID not found
+}

src/proc_operations.h

@@ -0,0 +1,55 @@
+/*
+  ICFS: Interactively Controlled File System
+  Copyright (C) 2024-2025  Fedir Kovalov
+
+  This program can be distributed under the terms of the GNU GPLv2.
+  See the file LICENSE.
+*/
+
+#ifndef PROC_OPERATIONS
+#define PROC_OPERATIONS
+
+#include <time.h>
+
+/**
+ * @brief Retrieves the full path of the executable for a given process ID.
+ *
+ * This function reads the `/proc/<pid>/exe` symbolic link, which points to the
+ * executable file of the process. The returned string is dynamically allocated
+ * and must be freed by the caller.
+ *
+ * @param pid The process ID to query.
+ * @return char* Dynamically allocated string containing the executable path, or
+ * NULL on failure.
+ */
+char *get_process_name_by_pid(const int pid);
+
+/**
+ * @brief Finds the parent process ID of a given process.
+ *
+ * This function parses the `/proc/<pid>/status` file to extract the `PPid`
+ * field, which represents the parent process ID. This is useful for tracing
+ * process lineage.
+ *
+ * @param pid The process ID of the process to find the parent of.
+ * @return pid_t The parent process ID, or 0 if the parent could not be
+ * determined.
+ */
+pid_t get_parent_pid(pid_t pid);
+
+/**
+ * @brief Returns the PID of the main thread (i.e., the process ID) of the
+ * process that the given thread ID (tid) belongs to.
+ *
+ * In Linux, threads within the same process share the same thread group ID
+ * (TGID), which is equal to the PID of the main thread. This function retrieves
+ * the TGID by parsing `/proc/<tid>/status`, effectively returning the main
+ * thread's PID.
+ *
+ * @param tid The thread ID (TID) of any thread in the process.
+ * @return pid_t The process ID (main thread's PID), or 0 on error (invalid tid
+ * or file read failure).
+ */
+pid_t get_main_thread_pid(pid_t tid);
+
+#endif // !PROC_OPERATIONS

src/process_info.h

@@ -0,0 +1,33 @@
+/*
+  ICFS: Interactively Controlled File System
+  Copyright (C) 2024-2025  Fedir Kovalov
+
+  This program can be distributed under the terms of the GNU GPLv2.
+  See the file LICENSE.
+*/
+
+#ifndef PROCESS_INFO_H
+#define PROCESS_INFO_H
+
+#include "proc_operations.h"
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <unistd.h>
+struct process_info {
+  pid_t PID;
+  char *name;
+};
+
+static inline struct process_info get_process_info(pid_t pid) {
+  struct process_info pi;
+  pi.PID = get_main_thread_pid(pid);
+  pi.name = get_process_name_by_pid(pi.PID);
+  if (pi.name == NULL) {
+    pi.PID = 0;
+  }
+  return pi;
+}
+
+#endif // PROCESS_INFO_H

src/real_filename.h

@@ -0,0 +1,26 @@
+/*
+  ICFS: Interactively Controlled File System
+  Copyright (C) 2024-2025  Fedir Kovalov
+
+  This program can be distributed under the terms of the GNU GPLv2.
+  See the file LICENSE.
+*/
+
+#ifndef REAL_FILENAME_H
+#define REAL_FILENAME_H
+
+/**
+ * @brief Build a real path to the file.
+ *
+ * @param filename Relative path within the filesystem
+ * @return Newly allocated absolute path (caller must free)
+ */
+const char *real_filename(const char *filename);
+
+/**
+ * @brief Get the current mount point path
+ * @return Absolute path to the filesystem root
+ */
+const char *get_mountpoint(void);
+
+#endif // !REAL_FILENAME_H

src/set_mode_t.h

@@ -0,0 +1,12 @@
+/*
+  ICFS: Interactively Controlled File System
+  Copyright (C) 2024-2025  Fedir Kovalov
+
+  This program can be distributed under the terms of the GNU GPLv2.
+  See the file LICENSE.
+*/
+
+#ifndef SET_MODE_T_H
+#define SET_MODE_T_H
+typedef enum { SET_DENY, SET_ALLOW } set_mode_t;
+#endif // !SET_MODE_T_H

src/sourcefs.c

@@ -1,74 +1,203 @@
+/*
+  ICFS: Interactively Controlled File System
+  Copyright (C) 2024-2025  Fedir Kovalov
+
+  This program can be distributed under the terms of the GNU GPLv2.
+  See the file LICENSE.
+*/
+
 #define _GNU_SOURCE
 
 #include "sourcefs.h"
 #include <dirent.h>
-#include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
-#include <sys/stat.h>
 #include <unistd.h>
 
+/**
+ * @brief Global handle for the source filesystem implementation
+ *
+ * Stores the root directory information to enable relative path operations.
+ */
 static struct source_files_handle {
-  int root_fd;
+  char *mountpoint; // Absolute path to the mounted filesystem root
+  int root_fd;      // File descriptor for the root directory (O_PATH)
 } handle;
 
+/**
+ * @brief Translate FUSE paths to real paths in the underlying filesystem
+ *
+ * FUSE passes paths starting with '/' (e.g., "/dir/file"), but we need to
+ * operate relative to our root_fd. This function converts:
+ * - "/" -> "." (current directory)
+ * - "/dir/file" -> "dir/file"
+ *
+ * @param filename Path from FUSE (always starts with '/')
+ * @return Relative path suitable for use with root_fd
+ */
 const char *source_filename_translate(const char *filename) {
   if (strcmp("/", filename) == 0) {
     return ".";
-  } else {
-    return filename + 1;
   }
+  return filename + 1; // Skip leading slash
 }
 
+/**
+ * @brief Initialize the source filesystem with a root directory
+ *
+ * Sets up the mount point and opens a protected file descriptor to the
+ * root directory for safe relative operations.
+ *
+ * @param root_path Absolute path to the physical root directory
+ * @return 0 on success, -1 on failure
+ */
 int source_init(const char *root_path) {
-  int root_fd = open(root_path, O_PATH);
+  // Allocate memory for mount point path
+  handle.mountpoint = malloc(strlen(root_path) + 1);
+  if (handle.mountpoint == NULL) {
+    perror("[ICFS] Malloc failed");
+    return -1;
+  }
 
+  strcpy(handle.mountpoint, root_path);
+
+  // Open root directory with O_PATH to prevent accidental reads/writes
+  // while maintaining a valid descriptor for relative operations
+  int root_fd = open(root_path, O_PATH);
   if (root_fd == -1) {
+    fprintf(stderr, "[ICFS] Could not initialize source file system at %s",
+            root_path);
+    perror("");
     return -1;
   }
 
   handle.root_fd = root_fd;
-
   return 0;
 }
 
+/**
+ * @brief Clean up resources used by the source filesystem
+ */
+void source_destroy(void) {
+  free(handle.mountpoint); // Free allocated mount point path
+}
+
+/**
+ * @brief Get the current mount point path
+ * @return Absolute path to the filesystem root
+ */
+const char *get_mountpoint(void) { return handle.mountpoint; }
+
+/**
+ * @brief Build a real path to the file.
+ *
+ * @param filename Relative path within the filesystem
+ * @return Newly allocated absolute path (caller must free)
+ */
+const char *real_filename(const char *filename) {
+  const char *mountpoint = get_mountpoint();
+  size_t len1 = strlen(mountpoint);
+  size_t len2 = strlen(filename);
+
+  // Allocate space for combined path + null terminator
+  char *result = malloc(len1 + len2 + 1);
+  if (result == NULL) {
+    fprintf(stderr, "[ICFS] Memory allocation failed");
+    perror("");
+    return NULL;
+  }
+
+  strcpy(result, mountpoint);
+  strcat(result, filename);
+  return result;
+}
+
+/**
+ * @brief Create a directory in the filesystem
+ *
+ * Uses mkdirat() to safely create directories relative to root_fd,
+ * preventing race conditions from concurrent path modifications.
+ */
 int source_mkdir(const char *filename, mode_t mode) {
   const char *relative_filename = source_filename_translate(filename);
   return mkdirat(handle.root_fd, relative_filename, mode);
 }
 
+/**
+ * @brief Remove a file from the filesystem
+ *
+ * Uses unlinkat() to safely remove files relative to the root directory.
+ */
 int source_unlink(const char *filename) {
   const char *relative_filename = source_filename_translate(filename);
   return unlinkat(handle.root_fd, relative_filename, 0);
 }
 
+/**
+ * @brief Get file status information
+ *
+ * Uses fstatat() to retrieve metadata relative to root_fd. Follows symlinks
+ * by default (flags=0).
+ */
 int source_stat(const char *restrict filename, struct stat *restrict statbuf) {
   const char *relative_filename = source_filename_translate(filename);
   return fstatat(handle.root_fd, relative_filename, statbuf, 0);
 }
 
+/**
+ * @brief Remove an empty directory
+ *
+ * Uses unlinkat() with AT_REMOVEDIR flag to safely remove directories.
+ */
 int source_rmdir(const char *filename) {
   const char *relative_filename = source_filename_translate(filename);
   return unlinkat(handle.root_fd, relative_filename, AT_REMOVEDIR);
 }
 
+/**
+ * @brief Create a symbolic link
+ *
+ * Creates symlinks relative to the root_fd directory for safety.
+ */
 int source_symlink(const char *target, const char *linkpath) {
   const char *relative_linkpath = source_filename_translate(linkpath);
   return symlinkat(target, handle.root_fd, relative_linkpath);
 }
 
+/**
+ * @brief Check file access permissions
+ *
+ * Uses faccessat() to check access rights relative to root_fd.
+ */
+int source_access(const char *filename, int mode) {
+  const char *relative_filename = source_filename_translate(filename);
+  return faccessat(handle.root_fd, relative_filename, mode, 0);
+}
+
+/**
+ * @brief Open a directory for reading
+ *
+ * Combines openat() and fdopendir() to safely access directories relative
+ * to the root_fd.
+ */
 DIR *source_opendir(const char *filename) {
   const char *relative_filename = source_filename_translate(filename);
-  int fd = openat(handle.root_fd, relative_filename, NULL);
+  int fd = openat(handle.root_fd, relative_filename, 0);
   if (fd < 0) {
-    perror("Openat failed");
+    perror("[ICFS] Openat failed");
     return NULL;
   }
   DIR *dir_pointer = fdopendir(fd);
   return dir_pointer;
 }
 
+/**
+ * @brief Rename a file or directory
+ *
+ * Uses renameat() to safely rename within the same root_fd namespace.
+ */
 int source_rename(const char *oldpath, const char *newpath) {
   const char *relative_oldpath = source_filename_translate(oldpath);
   const char *relative_newpath = source_filename_translate(newpath);
@@ -76,41 +205,80 @@ int source_rename(const char *oldpath, const char *newpath) {
                   relative_newpath);
 }
 
+/**
+ * @brief Create a hard link
+ *
+ * Uses linkat() with flags=0 (default behavior). May need AT_SYMLINK_NOFOLLOW
+ * if symlink handling should be modified.
+ */
 int source_link(const char *oldpath, const char *newpath) {
   const char *relative_oldpath = source_filename_translate(oldpath);
   const char *relative_newpath = source_filename_translate(newpath);
   return linkat(handle.root_fd, relative_oldpath, handle.root_fd,
                 relative_newpath, 0);
-  // NOTE: perhaps the flags here need to be reevaluated.
 }
 
+/**
+ * @brief Change file access mode
+ *
+ * Uses fchmodat() with flags=0 (follow symlinks). Consider using
+ * AT_SYMLINK_NOFOLLOW if symlink metadata should be modified directly.
+ */
 int source_chmod(const char *filename, mode_t mode) {
   const char *relative_filename = source_filename_translate(filename);
   return fchmodat(handle.root_fd, relative_filename, mode, 0);
-  // NOTE: perhaps the flags here need to be reevaluated.
 }
 
+/**
+ * @brief Change file owner and group
+ *
+ * Uses fchownat() with AT_SYMLINK_NOFOLLOW to modify symlink metadata
+ * rather than its target.
+ */
 int source_chown(const char *filename, uid_t owner, gid_t group) {
   const char *relative_filename = source_filename_translate(filename);
   return fchownat(handle.root_fd, filename, owner, group, AT_SYMLINK_NOFOLLOW);
 }
 
+/**
+ * @brief Truncate a file to a specified length
+ *
+ * Opens the file with read-only access then truncates it. This may fail
+ * if the file wasn't opened with write permissions. Consider changing
+ * openat() flags to O_WRONLY for reliability.
+ */
 int source_truncate(const char *filename, off_t length) {
   const char *relative_filename = source_filename_translate(filename);
-  int fd = openat(handle.root_fd, relative_filename, NULL);
+  int fd = openat(handle.root_fd, relative_filename, 0);
   if (fd < 0) {
-    perror("Openat failed");
+    perror("[ICFS] Openat failed");
     return -1;
   }
   return ftruncate(fd, length);
 }
 
+/**
+ * @brief Open a file with specified flags
+ *
+ * Uses openat() to safely access files relative to root_fd.
+ */
 int source_open(const char *filename, int flags) {
   const char *relative_filename = source_filename_translate(filename);
   return openat(handle.root_fd, relative_filename, flags);
 }
 
+/**
+ * @brief Create and open a new file
+ *
+ * Uses openat() with O_CREAT to create files relative to root_fd.
+ */
 int source_create(const char *filename, int flags, mode_t mode) {
   const char *relative_filename = source_filename_translate(filename);
-  return openat(handle.root_fd, relative_filename, flags, mode);
+  return openat(handle.root_fd, relative_filename, flags | O_CREAT, mode);
+}
+
+int source_utimens(const char *filename, const struct timespec ts[2],
+                   int flags) {
+  const char *relative_filename = source_filename_translate(filename);
+  return utimensat(handle.root_fd, relative_filename, ts, AT_SYMLINK_NOFOLLOW);
 }

src/sourcefs.h

@@ -1,4 +1,10 @@
+/*
+  ICFS: Interactively Controlled File System
+  Copyright (C) 2024-2025  Fedir Kovalov
 
+  This program can be distributed under the terms of the GNU GPLv2.
+  See the file LICENSE.
+*/
 
 #ifndef SOURCEFS_H
 #define SOURCEFS_H
@@ -7,45 +13,132 @@
 #include <sys/stat.h>
 
 /**
- * Initializes the source file handling.
+ * @brief Initialize the source filesystem with a root directory
  *
- * @param root_path The root of the source files folder.
+ * Sets up the mount point and opens a protected file descriptor to the
- * @return 0 on success, -1 on failure.
+ * root directory for safe relative operations.
+ *
+ * @param root_path Absolute path to the physical root directory
+ * @return 0 on success, -1 on failure
  */
 int source_init(const char *root_path);
 
-/* All of the functions below are designed to behave exactly as their non-source
+/**
- * counterparts. */
+ * @brief Clean up resources used by the source filesystem
+ */
+void source_destroy(void);
 
+/**
+ * @brief Get file status information
+ *
+ * Uses fstatat() to retrieve metadata relative to root_fd. Follows symlinks
+ * by default (flags=0).
+ */
 int source_stat(const char *restrict filename, struct stat *restrict statbuf);
 
-struct dirent *source_readdir(DIR *dirp);
+/**
-
+ * @brief Open a directory for reading
+ *
+ * Combines openat() and fdopendir() to safely access directories relative
+ * to the root_fd.
+ */
 DIR *source_opendir(const char *filename);
 
+/**
+ * @brief Remove a file from the filesystem
+ *
+ * Uses unlinkat() with AT_REMOVEDIR flag to safely remove files relative
+ * to the root directory.
+ */
 int source_unlink(const char *filename);
 
+/**
+ * @brief Create a directory in the filesystem
+ *
+ * Uses mkdirat() to safely create directories relative to root_fd,
+ * preventing race conditions from concurrent path modifications.
+ */
 int source_mkdir(const char *filename, mode_t mode);
 
+/**
+ * @brief Remove an empty directory
+ *
+ * Uses unlinkat() with AT_REMOVEDIR flag to safely remove directories.
+ */
 int source_rmdir(const char *filename);
 
+/**
+ * @brief Create a symbolic link
+ *
+ * Creates symlinks relative to the root_fd directory for safety.
+ */
 int source_symlink(const char *target, const char *linkpath);
 
+/**
+ * @brief Rename a file or directory
+ *
+ * Uses renameat() to safely rename within the same root_fd namespace.
+ */
 int source_rename(const char *oldpath, const char *newpath);
 
+/**
+ * @brief Create a hard link
+ *
+ * Uses linkat() with flags=0 (default behavior). May need AT_SYMLINK_NOFOLLOW
+ * if symlink handling should be modified.
+ */
 int source_link(const char *oldpath, const char *newpath);
 
+/**
+ * @brief Change file access mode
+ *
+ * Uses fchmodat() with flags=0 (follow symlinks). Consider using
+ * AT_SYMLINK_NOFOLLOW if symlink metadata should be modified directly.
+ */
 int source_chmod(const char *filename, mode_t mode);
 
+/**
+ * @brief Change file owner and group
+ *
+ * Uses fchownat() with AT_SYMLINK_NOFOLLOW to modify symlink metadata
+ * rather than its target.
+ */
 int source_chown(const char *filename, uid_t owner, gid_t group);
 
+/**
+ * @brief Truncate a file to a specified length
+ *
+ * Opens the file with read-only access then truncates it. This may fail
+ * if the file wasn't opened with write permissions. Consider changing
+ * openat() flags to O_WRONLY for reliability.
+ */
 int source_truncate(const char *filename, off_t length);
 
+/**
+ * @brief Check file access permissions
+ *
+ * Uses faccessat() to check access rights relative to root_fd.
+ */
+int source_access(const char *filename, int mode);
+
 /* `open` and `create` are designed to correspond to fuse operations, not the
  * libc's `open(2)`. Both of them actually call `openat`. */
 
+/**
+ * @brief Open a file with specified flags
+ *
+ * Uses openat() to safely access files relative to root_fd.
+ */
 int source_open(const char *filename, int flags);
 
+/**
+ * @brief Create and open a new file
+ *
+ * Uses openat() with O_CREAT to create files relative to root_fd.
+ */
 int source_create(const char *filename, int flags, mode_t mode);
 
+int source_utimens(const char *filename, const struct timespec ts[2],
+                   int flags);
+
 #endif // !SOURCEFS_H

src/temp_permissions_table.c

@@ -0,0 +1,382 @@
+/*
+  ICFS: Interactively Controlled File System
+  Copyright (C) 2024-2025  Fedir Kovalov
+
+  This program can be distributed under the terms of the GNU GPLv2.
+  See the file LICENSE.
+*/
+
+#include "temp_permissions_table.h"
+#include "access_t.h"
+#include "cc.h"
+#include "proc_operations.h"
+#include "process_info.h"
+#include <pthread.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+
+#define GC_INTERVAL 1 // Garbage collection time interval.
+
+/**
+ * @struct temp_process_permissions
+ * @brief Stores temporary file access permissions for a process
+ *
+ * This structure tracks temporary file access permissions for a specific
+ * process. The permissions are tied to the process's lifetime using its
+ * creation time.
+ */
+struct temp_process_permissions {
+  unsigned long long creation_time; /**< Process creation time */
+  vec(char *) allowed_files; /**< List of allowed file paths (prefixes) */
+  vec(char *) denied_files;  /**< List of denied file paths (prefixes) */
+};
+
+/**
+ * @brief Global table mapping PIDs to temporary permissions
+ *
+ * This map stores the temporary file access permissions for processes.
+ * Entries are keyed by process ID (pid_t) and contain temp_process_permissions
+ * structures with the access rules.
+ */
+map(pid_t, struct temp_process_permissions) temp_permissions_table;
+
+/**
+ * @brief Read-write lock for thread-safe access to temp_permissions_table
+ *
+ * A read-write lock to ensure thread-safe operations on the
+ * temp_permissions_table. Allows concurrent reads but exclusive writes.
+ */
+pthread_rwlock_t temp_permissions_table_lock = PTHREAD_RWLOCK_INITIALIZER;
+
+/**
+ * @brief Thread handle for the garbage collector
+ *
+ * This thread handles cleanup of stale entries in the temp_permissions_table.
+ */
+pthread_t gc_thread;
+
+/**
+ * @brief Flag indicating whether garbage collector is active
+ *
+ * When non-zero, indicates that the garbage collector thread should continue
+ * running.
+ */
+int is_gc_active = 0;
+
+/**
+ * Function to get the process creation time from the proc
+ * filesystem
+ *
+ * @param pid The process ID of the process to get the creation time of
+ * @return The process creation time, or 0 on error
+ * @note although nothing in the documentation says that the creation time is
+ * never really equal to 0, it exceptionally unlikely.
+ */
+unsigned long long get_process_creation_time(pid_t pid) {
+  char path[256];
+  FILE *fp = NULL;
+  unsigned long long creation_time = 0;
+
+  // Construct the path to the process's status file
+  snprintf(path, sizeof(path), "/proc/%u/stat", pid);
+
+  // Open the status file
+  fp = fopen(path, "r");
+  if (fp == NULL) {
+    perror("[ICFS] fopen");
+    return 0;
+  }
+
+  // Read the creation time (the 22nd field in the stat file)
+  for (int i = 1; i < 22; i++) {
+    if (fscanf(fp, "%*s") == EOF) {
+      fprintf(stderr,
+              "[ICFS] Error reading process stat file on the number %d\n", i);
+      fclose(fp);
+      return 0;
+    }
+  }
+  if (fscanf(fp, "%llu", &creation_time) != 1) {
+    fprintf(stderr, "[ICFS] Error reading creation time\n");
+    fclose(fp);
+    return 0;
+  }
+
+  // Close the file
+  fclose(fp);
+
+  return creation_time;
+}
+
+/**
+ * @brief Validates if a process entry is still valid
+ *
+ * Checks if the given process entry matches the current process state
+ * by comparing creation times.
+ *
+ * @param pid Process ID to validate
+ * @param entry Pointer to the permission entry to validate
+ * @return 1 if valid, 0 if invalid or error
+ */
+int is_valid(pid_t pid, struct temp_process_permissions *entry) {
+  unsigned long long creation_time = get_process_creation_time(pid);
+  if (creation_time == 0) {
+    return 0;
+  }
+
+  // If the creation time doesn't match, this is a different process instance
+  if (creation_time != entry->creation_time) {
+    return 0;
+  }
+
+  return 1;
+}
+
+/**
+ * @brief Garbage collector thread for cleaning up stale entries
+ *
+ * Periodically scans the permissions table and removes entries for processes
+ * that no longer exist. Runs every second while is_gc_active is true.
+ *
+ * @param arg Unused thread argument parameter
+ * @return Always NULL
+ */
+void *garbage_collector(void *arg) {
+  (void)arg;
+
+  while (is_gc_active) {
+    sleep(GC_INTERVAL); // Check once per second for stale entries
+    pthread_rwlock_wrlock(&temp_permissions_table_lock);
+
+    vec(pid_t) blacklist;
+    init(&blacklist);
+
+    // Identify stale entries
+    for_each(&temp_permissions_table, pid, entry) {
+      if (!is_valid(*pid, entry)) {
+        push(&blacklist, *pid);
+        // Free memory for this entry's file lists
+        for_each(&entry->allowed_files, allowed_file) { free(*allowed_file); }
+        cleanup(&entry->allowed_files);
+        for_each(&entry->denied_files, denied_file) { free(*denied_file); }
+        cleanup(&entry->denied_files);
+      }
+    }
+
+    // Remove all stale entries from the table
+    for_each(&blacklist, pid) { erase(&temp_permissions_table, *pid); }
+
+    cleanup(&blacklist);
+
+    pthread_rwlock_unlock(&temp_permissions_table_lock);
+  }
+
+  return NULL;
+}
+
+/**
+ * Initializes the temporary permissions table.
+ *
+ * @return 0 on success, -1 on failure
+ */
+int init_temp_permissions_table(void) {
+  init(&temp_permissions_table);
+  return 0;
+}
+/**
+ * Starts the temporary permissions table garbage_collector.
+ *
+ * @return 0 on success, -1 on failure
+ */
+int init_garbage_collector(void) {
+  is_gc_active = 1;
+  if (pthread_create(&gc_thread, NULL, garbage_collector, NULL) != 0) {
+    return -1;
+  }
+  return 0;
+}
+
+/**
+ * Destroys the temporary permissions table.
+ *
+ * @note the table is guranteed to be destroyed if it is already initialized.
+ * It does not indicate any errors whatsoever. If something goes wrong - you are
+ * screwed.
+ */
+void destroy_temp_permissions_table(void) {
+  if (is_gc_active) {
+    is_gc_active = 0;
+    pthread_join(gc_thread, NULL);
+  }
+
+  // Free the memory allocated for the table
+  for_each(&temp_permissions_table, entry) {
+    for_each(&entry->allowed_files, allowed_file) { free(*allowed_file); }
+    cleanup(&entry->allowed_files);
+  }
+  for_each(&temp_permissions_table, entry) {
+    for_each(&entry->denied_files, denied_file) { free(*denied_file); }
+    cleanup(&entry->denied_files);
+  }
+
+  cleanup(&temp_permissions_table);
+}
+
+/**
+ * @brief Checks if a specific process has temporary access to a file
+ *
+ * Checks only the specified process (not its parents) for temporary access
+ * permissions to the given file. Uses a longest-match algorithm for path
+ * prefixes.
+ *
+ * @param filename Path to the file being accessed
+ * @param pid Process ID of the process to check
+ * @return Access status ALLOW, DENY, or NDEF (no information)
+ */
+access_t check_temp_access_noparent(const char *filename, pid_t pid) {
+  pthread_rwlock_rdlock(&temp_permissions_table_lock);
+  struct temp_process_permissions *permission_entry =
+      get(&temp_permissions_table, pid);
+  if (permission_entry != NULL) {
+    unsigned long long process_creation_time = get_process_creation_time(pid);
+    if (process_creation_time == 0) {
+      perror("[ICFS] Could not retrieve process creation time");
+      pthread_rwlock_unlock(&temp_permissions_table_lock);
+      return NDEF;
+    }
+
+    if (process_creation_time == permission_entry->creation_time) {
+      // The process is the same as the one that was granted temporary access
+      size_t filename_len = strlen(filename);
+      access_t ret = NDEF;
+      size_t maxlen = 0;
+
+      // Check denied files first (deny takes precedence over allow)
+      for_each(&permission_entry->denied_files, denied_file) {
+        size_t denied_file_len = strlen(*denied_file);
+        // Check if this denied path prefix matches the requested file
+        if ((strncmp(*denied_file, filename, denied_file_len) == 0 &&
+             ((denied_file_len < filename_len &&
+               (*denied_file)[denied_file_len - 1] == '/') ||
+              (denied_file_len == filename_len))) &&
+            denied_file_len > maxlen) {
+          maxlen = denied_file_len;
+          ret = DENY;
+        }
+      }
+
+      // Check allowed files
+      for_each(&permission_entry->allowed_files, allowed_file) {
+        size_t allowed_file_len = strlen(*allowed_file);
+        // Check if this allowed path prefix matches the requested file
+        if ((strncmp(*allowed_file, filename, allowed_file_len) == 0 &&
+             ((allowed_file_len < filename_len &&
+               (*allowed_file)[allowed_file_len - 1] == '/') ||
+              (allowed_file_len == filename_len))) &&
+            allowed_file_len > maxlen) {
+          maxlen = allowed_file_len;
+          ret = ALLOW;
+        }
+      }
+
+      pthread_rwlock_unlock(&temp_permissions_table_lock);
+      return ret;
+    }
+  }
+  pthread_rwlock_unlock(&temp_permissions_table_lock);
+  return NDEF;
+}
+
+/**
+ * Checks if the process or any of it's parents have temporary access to the
+ * file.
+ *
+ * @param filename The file that the process is trying to access
+ * @param pi The process information
+ * @return access status - ALLOW, DENY or NDEF in case if no information was
+ * found. Does not return ALLOW_TEMP.
+ * @note In case one of the parent processes is killed while this function
+ * execution the result is not guranteed to be correct. It should only
+ * false negatives, though.
+ */
+access_t check_temp_access(const char *filename, struct process_info pi) {
+  pid_t current_pid = pi.PID;
+  while (current_pid != 0) {
+    access_t access = check_temp_access_noparent(filename, current_pid);
+    if (access != NDEF) {
+      return access;
+    }
+    current_pid = get_main_thread_pid(get_parent_pid(current_pid));
+  }
+
+  return NDEF;
+}
+
+/**
+ * Sets temporary access mode of the process to the file.
+ *
+ * @param filename The file that the process is trying to access
+ * @param pi The process information
+ * @param mode Kind of access rule to be set - SET_DENY to deny access, and
+ * SET_ALLOW to allow access.
+ * @return 0 on success, -1 on failure.
+ */
+int set_temp_access(const char *filename, struct process_info pi,
+                    set_mode_t mode) {
+  if (pi.PID == 0)
+    return NDEF;
+  pthread_rwlock_wrlock(&temp_permissions_table_lock);
+  struct temp_process_permissions *permission_entry =
+      get(&temp_permissions_table, pi.PID);
+
+  if (permission_entry != NULL) {
+
+    unsigned long long process_creation_time =
+        get_process_creation_time(pi.PID);
+    if (process_creation_time == 0) {
+      perror("[ICFS] Could not retrieve process creation time");
+      pthread_rwlock_unlock(&temp_permissions_table_lock);
+      return -1;
+    }
+
+    if (process_creation_time == permission_entry->creation_time) {
+      // The process is the same as the one that was granted temporary access
+      if (mode == SET_ALLOW) {
+        push(&permission_entry->allowed_files, strdup(filename));
+      }
+      if (mode == SET_DENY) {
+        push(&permission_entry->denied_files, strdup(filename));
+      }
+
+      pthread_rwlock_unlock(&temp_permissions_table_lock);
+      return 0;
+    }
+    // We have an entry for the process, but the process is different
+    // Delete the entry and create a new one
+    erase(&temp_permissions_table, pi.PID);
+    permission_entry = NULL;
+  }
+
+  // No entry is present - construct a new one
+  struct temp_process_permissions new_permission_entry;
+
+  new_permission_entry.creation_time = get_process_creation_time(pi.PID);
+  init(&new_permission_entry.allowed_files);
+  init(&new_permission_entry.denied_files);
+
+  if (mode == SET_ALLOW) {
+    push(&new_permission_entry.allowed_files, strdup(filename));
+  }
+  if (mode == SET_DENY) {
+    push(&new_permission_entry.denied_files, strdup(filename));
+  }
+
+  insert(&temp_permissions_table, pi.PID, new_permission_entry);
+
+  pthread_rwlock_unlock(&temp_permissions_table_lock);
+  return 0;
+}

src/temp_permissions_table.h

@@ -0,0 +1,65 @@
+/*
+  ICFS: Interactively Controlled File System
+  Copyright (C) 2024-2025  Fedir Kovalov
+
+  This program can be distributed under the terms of the GNU GPLv2.
+  See the file LICENSE.
+*/
+
+#ifndef TEMP_PERMISSIONS_TABLE_H
+#define TEMP_PERMISSIONS_TABLE_H
+
+#include "access_t.h"
+#include "process_info.h"
+#include "set_mode_t.h"
+
+/**
+ * Initializes the temporary permissions table.
+ *
+ * @return: 0 on success, -1 on failure
+ */
+int init_temp_permissions_table(void);
+
+/**
+ * Starts the temporary permissions table garbage_collector.
+ *
+ * @return 0 on success, -1 on failure
+ */
+int init_garbage_collector(void);
+
+/**
+ * Destroys the temporary permissions table.
+ *
+ * @note the table is guranteed to be destroyed if it is already initialized.
+ * It does not indicate any errors whatsoever. If something goes wrong - you are
+ * screwed.
+ */
+void destroy_temp_permissions_table(void);
+
+/**
+ * Checks if the process or any of it's parents have temporary access to the
+ * file.
+ *
+ * @param filename The file that the process is trying to access
+ * @param pi The process information
+ * @return access status - ALLOW, DENY or NDEF in case if no information was
+ * found. Does not return ALLOW_TEMP.
+ * @note In case one of the parent processes is killed while this function
+ * execution the result is not guranteed to be correct. It should only
+ * false negatives, though.
+ */
+access_t check_temp_access(const char *filename, struct process_info pi);
+
+/**
+ * Sets temporary access mode of the process to the file.
+ *
+ * @param filename The file that the process is trying to access
+ * @param pi The process information
+ * @param mode Kind of access rule to be set - SET_DENY to deny access, and
+ * SET_ALLOW to allow access.
+ * @return 0 on success, -1 on failure.
+ */
+int set_temp_access(const char *filename, struct process_info pi,
+                    set_mode_t mode);
+
+#endif // !TEMP_PERMISSIONS_TABLE_H

src/ui-socket.c

@@ -1,8 +1,24 @@
+/*
+  ICFS: Interactively Controlled File System
+  Copyright (C) 2024-2025  Fedir Kovalov
+
+  This program can be distributed under the terms of the GNU GPLv2.
+  See the file LICENSE.
+*/
+
+#include "access_t.h"
+#include <signal.h>
 #include <stddef.h>
 #include <sys/types.h>
-#define _GNU_SOURCE
+#include <time.h>
+#define _GNU_SOURCE // Required for certain POSIX extensions
+#include "cc.h"
+#include "perm_permissions_table.h"
+#include "real_filename.h"
+#include "sourcefs.h"
+#include "temp_permissions_table.h"
 #include "ui-socket.h"
-#include <errno.h>
+#include <assert.h>
 #include <pthread.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -10,47 +26,330 @@
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <unistd.h>
+#include <wait.h>
 
-int init_ui_socket(const char *filename) {
+// Exit status codes for icfs_dialogue process interaction
-  char line[256];
+#define DIALOGUE_YES 1
-  FILE *fp;
+#define DIALOGUE_NO 0
+#define DIALOGUE_PERM 2
+#define DIALOGUE_TEMP 0 // Bitmask position, not value
 
-  // Test if Zenity is installed (get version)
+// Mutex to protect concurrent access to permission tables
-  fp = popen("zenity --version", "r");
+pthread_mutex_t access_check_mutex = PTHREAD_MUTEX_INITIALIZER;
-  if (fp == NULL) {
+
-    perror("Pipe returned a error");
+// Structure to hold user permission decision response
+struct dialogue_response {
+  access_t decision;
+  char *filename;
+};
+
+/**
+ * Initialize UI socket and required permission tables
+ *
+ * @param perm_permissions_db_filename Path to persistent permissions DB
+ * @return 0 on success, 1 on failure
+ */
+int init_ui_socket(const char *perm_permissions_db_filename) {
+  FILE *fp = NULL;
+
+  // Initialize in-memory temporary permissions table
+  if (init_temp_permissions_table()) {
+    fprintf(stderr,
+            "[ICFS] Could not initialize temporary permissions table.\n");
     return 1;
+  }
+
+  // Initialize permanent permissions database
+  if (init_perm_permissions_table(perm_permissions_db_filename)) {
+    fprintf(stderr,
+            "[ICFS] Could not initialize permanent permissions table.\n");
+    return 1;
+  }
+
+  // Verify dialogue utility is available
+  fp = popen("icfs_dialogue --version", "r");
+  if (fp == NULL) {
+    perror("[ICFS] Pipe returned an error");
+    return 1;
+  }
+
+  pclose(fp);
+  return 0;
+}
+
+/**
+ * Clean up UI socket resources
+ */
+void destroy_ui_socket(void) {
+  destroy_temp_permissions_table();
+  destroy_perm_permissions_table();
+}
+
+/**
+ * Query user for file access permission through GUI dialogue
+ *
+ * Constructs and executes the icfs_dialogue command to get user consent.
+ * Handles memory allocation errors gracefully and parses the response.
+ *
+ * @param filename File being accessed
+ * @param proc_info Process requesting access
+ * @return Struct containing access decision and resolved filename
+ */
+struct dialogue_response ask_access(const char *filename,
+                                    struct process_info proc_info) {
+  FILE *fp = NULL;
+
+  struct dialogue_response response;
+  response.decision = DENY;
+  response.filename = NULL;
+
+  // instead of popeen --------------
+
+  char pid_str[sizeof(pid_t) *
+               8]; // amount of bits should be enough for a decimal
+  snprintf(pid_str, sizeof(pid_str), "%d", proc_info.PID);
+
+  int pipefd[2];
+  if (pipe(pipefd) == -1) {
+    perror("[ICFS] pipe returned a error");
+    response.filename = malloc(2);
+    response.filename[0] = '/';
+    response.filename[1] = 0;
+    return response;
+  }
+
+  pid_t pid = fork();
+  if (pid == -1) {
+    perror("[ICFS] fork returned a error");
+    response.filename = malloc(2);
+    response.filename[0] = '/';
+    response.filename[1] = 0;
+    return response;
+  }
+
+  if (pid == 0) {
+    // Child process
+    close(pipefd[0]);               // Close read end
+    dup2(pipefd[1], STDOUT_FILENO); // Redirect stdout
+    close(pipefd[1]);               // Close original write end
+
+    // Prepare command and arguments
+    char *args[] = {"icfs_dialogue", // Command name (looked up in PATH)
+                    pid_str,
+                    (char *)proc_info.name,
+                    (char *)get_mountpoint(),
+                    (char *)filename,
+                    NULL};
+
+    // Execute the command using execvp (uses PATH)
+    execvp("icfs_dialogue", args);
+
+    // If execvp fails
+    perror("execvp failed");
+    exit(EXIT_FAILURE);
+  }
+
+  // instead of popen ---------------
+
+  close(pipefd[1]); // Close write end
+  fp = fdopen(pipefd[0], "r");
+
+  if (fp == NULL) {
+    perror("[ICFS] fdopen returned a error");
+    response.filename = malloc(2);
+    response.filename[0] = '/';
+    response.filename[1] = 0;
+    return response;
+  }
+
+  str(char) dialogue_output;
+  init(&dialogue_output);
+
+  char line[1024];
+
+  // Read entire command output
+  while (fgets(line, sizeof(line), fp)) {
+    if (push_fmt(&dialogue_output, line) == NULL) {
+      cleanup(&dialogue_output);
+      perror("[ICFS] not enough memory for dialogue output.");
+      // kill the dialogue if it's still there
+      kill(pid, SIGQUIT);
+      fclose(fp);
+      response.filename = malloc(2);
+      response.filename[0] = '/';
+      response.filename[1] = 0;
+      return response;
+    }
+  }
+
+  fclose(fp);
+
+  // Wait for the child to finish
+  int status;
+  if (waitpid(pid, &status, 0) == -1) {
+    cleanup(&dialogue_output);
+    perror("[ICFS] waitpid error");
+    // kill the dialogue if it is still there
+    kill(pid, SIGQUIT);
+    response.filename = malloc(2);
+    response.filename[0] = '/';
+    response.filename[1] = 0;
+    return response;
+  }
+
+  int dialogue_exit_code = WEXITSTATUS(status);
+
+  fprintf(stderr, "[ICFS] dialogue wrote out %s\n", first(&dialogue_output));
+  fprintf(stderr, "[ICFS] dialogue returned %d\n", dialogue_exit_code);
+
+  // Handle empty output case
+  if (size(&dialogue_output) == 0) {
+    perror("[ICFS] empty dialogue output.");
+    push(&dialogue_output, '/');
+  }
+
+  // Allocate and copy final filename
+  response.filename = malloc(size(&dialogue_output) + 1);
+  strcpy(response.filename, first(&dialogue_output));
+  cleanup(&dialogue_output);
+
+  // Parse exit code combination
+  if (dialogue_exit_code == (DIALOGUE_YES | DIALOGUE_PERM)) {
+    response.decision = ALLOW;
+  } else if (dialogue_exit_code == DIALOGUE_YES | DIALOGUE_TEMP) {
+    response.decision = ALLOW_TEMP;
+  } else if (dialogue_exit_code == (DIALOGUE_NO | DIALOGUE_PERM)) {
+    response.decision = DENY;
   } else {
-    while (fgets(line, sizeof(line), fp))
+    response.decision = DENY_TEMP;
-      printf("%s", line);
+  }
-    pclose(fp);
+
+  return response;
+}
+
+/**
+ * Determine file access based on permission tables and user input
+ *
+ * Checks permissions in order:
+ * 1. Temporary permission table
+ * 2. Permanent permission table
+ * 3. User decision via GUI
+ *
+ * @param filename File being accessed
+ * @param pi Process information
+ * @param opts Flags to force permission (GRANT_TEMP/GRANT_PERM)
+ * @return 1 if access allowed, 0 if denied
+ */
+int interactive_access(const char *filename, struct process_info proc_info,
+                       int opts) {
+  char *real_path = real_filename(filename);
+  pthread_mutex_lock(&access_check_mutex);
+
+  // First check temporary permissions
+  access_t access = check_temp_access(real_path, proc_info);
+  if (access == ALLOW) {
+    fprintf(stderr, "[ICFS] Permission allowed to %s based on temp table.\n",
+            proc_info.name);
+    free(real_path);
+    pthread_mutex_unlock(&access_check_mutex);
+    return 1;
+  }
+  if (access == DENY) {
+    fprintf(stderr, "[ICFS] Permission denied to %s based on temp table.\n",
+            proc_info.name);
+    free(real_path);
+    pthread_mutex_unlock(&access_check_mutex);
     return 0;
   }
-}
 
-/*
+  // Then check permanent permissions
- * This function is called from the FUSE operations functions. Those are called
+  access = check_perm_access(real_path, proc_info);
- * from separate threads. Therefore, there can be multiple threads that try to
+  if (access == ALLOW) {
- * ask for access at the same time, but we have to
+    fprintf(stderr, "[ICFS] Permission allowed to %s based on perm table.\n",
- */
+            proc_info.name);
-
+    free(real_path);
-int ask_access(const char *filename, struct process_info pi) {
+    pthread_mutex_unlock(&access_check_mutex);
-
+    return 1;
-  FILE *fp;
-  size_t command_len =
-      139 + sizeof(pid_t) * 8 + strlen(pi.name) + strlen(filename);
-  char *command = (char *)malloc(command_len);
-  snprintf(command, command_len,
-           "zenity --question --title \"Allow Access?\" --text \"Allow process "
-           "<tt>%s</tt> with PID <tt>%d</tt> to access <tt>%s</tt>\"",
-           pi.name, pi.PID, filename);
-  // Zenity Question Message Popup
-  fp = popen(command, "r");
-  free(command);
-  if (fp == NULL) {
-    perror("Pipe returned a error");
-    return -1;
-  } else {
-    return WEXITSTATUS(pclose(fp));
   }
+  if (access == DENY) {
+    fprintf(stderr, "[ICFS] Permission denied to %s based on perm table.\n",
+            proc_info.name);
+    free(real_path);
+    pthread_mutex_unlock(&access_check_mutex);
+    return 0;
+  }
+
+  // Handle forced permission grants
+  if (opts & GRANT_PERM) {
+    fprintf(stderr, "[ICFS] Permission granted permanently to %s.\n",
+            proc_info.name);
+    set_perm_access(real_path, proc_info, SET_ALLOW);
+    free(real_path);
+    pthread_mutex_unlock(&access_check_mutex);
+    return 1;
+  }
+  if (opts & GRANT_TEMP) {
+    fprintf(stderr, "[ICFS] Permission granted temporarily to %s.\n",
+            proc_info.name);
+    set_temp_access(real_path, proc_info, SET_ALLOW);
+    free(real_path);
+    pthread_mutex_unlock(&access_check_mutex);
+    return 1;
+  }
+
+  // Get user decision
+  struct dialogue_response response = ask_access(filename, proc_info);
+
+  // Validate returned filename meets requirements:
+  // 1. Must exist
+  // 2. Must be prefix of original filename with trailing slash
+  //    or exact match
+  while (
+      source_access(response.filename, F_OK) ||
+      !(strncmp(response.filename, filename, strlen(response.filename)) == 0 &&
+        ((strlen(response.filename) < strlen(filename) &&
+          response.filename[strlen(response.filename) - 1] == '/') ||
+         (strlen(response.filename) == strlen(filename))))) {
+    fprintf(stderr, "[ICFS] Invalid filename returned by dialogue: %s\n",
+            response.filename);
+    free(response.filename);
+    response = ask_access(filename, proc_info);
+  }
+
+  free(real_path);
+  real_path = real_filename(response.filename);
+  free(response.filename);
+
+  int ret = 0;
+
+  // Apply user decision to appropriate permission table
+  if (response.decision == ALLOW) {
+    fprintf(stderr,
+            "[ICFS] Permission granted permanently to %s based on response.\n",
+            proc_info.name);
+    set_perm_access(real_path, proc_info, SET_ALLOW);
+    ret = 1;
+  } else if (response.decision == ALLOW_TEMP) {
+    fprintf(stderr,
+            "[ICFS] Permission granted temporarily to %s based on response.\n",
+            proc_info.name);
+    set_temp_access(real_path, proc_info, SET_ALLOW);
+    ret = 1;
+  } else if (response.decision == DENY_TEMP) {
+    fprintf(stderr,
+            "[ICFS] Permission denied temporarily to %s based on response.\n",
+            proc_info.name);
+    set_temp_access(real_path, proc_info, SET_DENY);
+    ret = 0;
+  } else if (response.decision == DENY) {
+    fprintf(stderr,
+            "[ICFS] Permission denied permanently to %s based on response.\n",
+            proc_info.name);
+    set_perm_access(real_path, proc_info, SET_DENY);
+    ret = 0;
+  }
+
+  pthread_mutex_unlock(&access_check_mutex);
+  free(real_path);
+  return ret;
 }

src/ui-socket.h

@@ -1,22 +1,47 @@
-
 /*
- * Interface for controlling communication with the UI.
+  ICFS: Interactively Controlled File System
- */
+  Copyright (C) 2024-2025  Fedir Kovalov
+
+  This program can be distributed under the terms of the GNU GPLv2.
+  See the file LICENSE.
+*/
 
 #ifndef UI_SOCKET_H
 #define UI_SOCKET_H
 
+#include "process_info.h"
 #include <sys/types.h>
 
-struct process_info {
+/**
-  pid_t PID;
+ * Initialize UI socket and required permission tables
-  const char *name;
+ *
-  uid_t UID;
+ * @param perm_permissions_db_filename Path to persistent permissions DB
-};
+ * @return 0 on success, 1 on failure
+ */
+int init_ui_socket(const char *perm_permissions_db_filename);
 
-// For default socket location, set socket_path = NULL.
+/**
-int init_ui_socket(const char *socket_path);
+ * Clean up UI socket resources
+ */
+void destroy_ui_socket(void);
 
-int ask_access(const char *filename, struct process_info pi);
+/**
+ * Determine file access based on permission tables and user input
+ *
+ * Checks permissions in order:
+ * 1. Temporary permission table
+ * 2. Permanent permission table
+ * 3. User decision via GUI
+ *
+ * @param filename File being accessed
+ * @param pi Process information
+ * @param opts Flags to force permission (GRANT_TEMP/GRANT_PERM)
+ * @return 1 if access allowed, 0 if denied
+ */
+int interactive_access(const char *filename, struct process_info pi, int opts);
+
+#define GRANT_TEMP 1
+#define GRANT_PERM 2
+// #define TABLE_ONLY 4 // NOTE: Add this in the future?
 
 #endif // !UI_SOCKET_H

test/mock/icfs_dialogue

@@ -0,0 +1,42 @@
+#!/bin/bash
+
+# fake-icfs_dialogue: script that mocks the behavior of icfs_dialogue based on the ./.fake-icfs_dialogue-response file
+
+ICFS_DIALOGUE_YES=1
+ICFS_DIALOGUE_NO=0
+ICFS_DIALOGUE_PERM=2
+ICFS_DIALOGUE_TEMP=0
+
+if [[ $1 == "--set-fake-response" ]]; then
+  #someone knows we are fake :)
+  echo "$2" >~/.fake_icfs_dialogue_response
+elif [[ $1 == "--set-fake-response-filename" ]]; then
+  echo "$2" >~/.fake_icfs_dialogue_response_filename
+elif [[ $1 == "--reset-fake-response" ]]; then
+  rm ~/.fake_icfs_dialogue_response ~/.fake_icfs_dialogue_response_filename
+else
+  if [ -f ~/.fake_icfs_dialogue_response ]; then
+    FAKE_ICFS_DIALOGUE_RESPONSE=$(cat ~/.fake_icfs_dialogue_response)
+
+    if [[ -f ~/.fake_icfs_dialogue_response_filename ]]; then
+      FAKE_ICFS_DIALOGUE_RESPONSE_FILENAME=$(cat ~/.fake_icfs_dialogue_response_filename)
+      if [[ $FAKE_ICFS_DIALOGUE_RESPONSE_FILENAME == "" ]]; then
+        printf "%s" "$4"
+      else
+        printf "%s" "$(cat ~/.fake_icfs_dialogue_response_filename)"
+      fi
+    fi
+
+    if [[ $FAKE_ICFS_DIALOGUE_RESPONSE == "yes" ]]; then
+      exit "$((ICFS_DIALOGUE_YES | ICFS_DIALOGUE_TEMP))"
+    elif [[ $FAKE_ICFS_DIALOGUE_RESPONSE == "no" ]]; then
+      exit "$((ICFS_DIALOGUE_NO | ICFS_DIALOGUE_TEMP))"
+    elif [[ $FAKE_ICFS_DIALOGUE_RESPONSE == "yes_perm" ]]; then
+      exit "$((ICFS_DIALOGUE_YES | ICFS_DIALOGUE_PERM))"
+    elif [[ $FAKE_ICFS_DIALOGUE_RESPONSE == "no_perm" ]]; then
+      exit "$((ICFS_DIALOGUE_NO | ICFS_DIALOGUE_PERM))"
+    fi
+  fi
+fi
+
+exit 255 # TODO: call actual icfs_dialogue here

test/opener/Makefile

@@ -0,0 +1,81 @@
+SHELL=/bin/bash
+
+# configurable options
+
+ifndef ($(SOURCES_DIR))
+	SOURCES_DIR := .
+endif
+
+ifndef ($(TESTS_DIR))
+	TESTS_DIR := .
+endif
+
+ifndef ($(BUILD_DIR))
+	BUILD_DIR := .
+endif
+
+CC := gcc
+CXX := g++
+
+NAME := opener
+
+# dependencies
+
+PACKAGE_NAMES :=
+
+ifeq ($(TEST), 1)
+	#	PACKAGE_NAMES += check # TODO: use check?
+endif
+
+
+# set up cflags and libs
+
+CFLAGS :=
+LDFLAGS :=
+
+ifneq ($(PACKAGE_NAMES),)
+	CFLAGS += $(shell pkg-config --cflags $(PACKAGE_NAMES))
+	LDFLAGS += $(shell pkg-config --libs $(PACKAGE_NAMES))
+endif
+
+ifeq ($(DEBUG),1)
+	CFLAGS += -O0 -pedantic -g -Wall -Wextra -Wcast-align \
+						-Wcast-qual -Wdisabled-optimization -Wformat=2 \
+						-Winit-self -Wlogical-op -Wmissing-declarations \
+						-Wmissing-include-dirs -Wredundant-decls -Wshadow \
+						-Wsign-conversion -Wstrict-overflow=5 \
+						-Wswitch-default -Wundef -Wno-unused
+	LDFLAGS += 
+else
+	CFLAGS += -O3
+	LDFLAGS +=
+endif
+
+
+# set up targets 
+
+TARGETS := $(BUILD_DIR)/$(NAME)
+
+ifeq ($(TEST), 1)
+	TARGETS += $(NAME)_test
+endif
+
+
+# build!
+
+default: $(TARGETS)
+
+.PHONY: clean $(NAME)_test
+
+$(NAME)_test: $(BUILD_DIR)/$(NAME)
+	echo "No tests defined."
+	#$(BUILD_DIR)/$(NAME)
+
+$(BUILD_DIR)/$(NAME): $(BUILD_DIR)/$(NAME).o
+	$(CC) $(CFLAGS) $^ $(LDFLAGS) -o $(BUILD_DIR)/$(NAME)
+
+$(BUILD_DIR)/$(NAME).o: $(SOURCES_DIR)/$(NAME).c
+	$(CC) $(CFLAGS) -c $< $(LDFLAGS) -o $(BUILD_DIR)/$(NAME).o
+
+clean:
+	rm $(BUILD_DIR)/*.o $(BUILD_DIR)/$(NAME)

test/opener/opener.c

@@ -0,0 +1,94 @@
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#define PATH_MAX 4096
+
+int main(int argc, char *argv[]) {
+  // Check for correct usage
+  if (argc != 2) {
+    fprintf(stderr, "Usage: %s <pathname>\n", argv[0]);
+    return 1;
+  }
+
+  const char *path = argv[1];
+  struct stat statbuf;
+
+  // Stat the given path to determine if it's a directory
+  if (lstat(path, &statbuf) == -1) {
+    perror("lstat");
+    return 1;
+  }
+
+  // Case 1: The path is not a directory
+  if (!S_ISDIR(statbuf.st_mode)) {
+    int fd = open(path, O_RDONLY);
+    if (fd == -1) {
+      perror("open");
+      return 1;
+    }
+    close(fd);
+    return 0;
+  }
+
+  // Case 2: The path is a directory
+  DIR *dirp = opendir(path);
+  if (dirp == NULL) {
+    perror("opendir");
+    return 1;
+  }
+
+  struct dirent *entry;
+  int success = 1;
+
+  while ((entry = readdir(dirp)) != NULL) {
+    // Skip . and ..
+    if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0) {
+      continue;
+    }
+
+    // Construct the full path
+    char *fullpath = NULL;
+    if (asprintf(&fullpath, "%s/%s", path, entry->d_name) == -1 ||
+        fullpath == NULL) {
+      perror("asprintf");
+      success = 0;
+      break;
+    }
+
+    // Stat the entry to check if it's a regular file
+    struct stat entry_stat;
+    if (lstat(fullpath, &entry_stat) == -1) {
+      perror("lstat");
+      success = 0;
+      free(fullpath);
+      break;
+    }
+
+    // Only process regular files
+    if (!S_ISREG(entry_stat.st_mode)) {
+      free(fullpath);
+      continue;
+    }
+
+    // Try to open and immediately close the file
+    int fd = open(fullpath, O_RDONLY);
+    free(fullpath);
+    if (fd == -1) {
+      perror("open");
+      success = 0;
+      break;
+    }
+    close(fd);
+  }
+
+  closedir(dirp);
+
+  return (success ? 0 : 1);
+}

test/stress.bash

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+count=$1
+for i in $(seq $count); do
+  $2 ./protected/haystack/
+done

test/test.bash

@@ -0,0 +1,240 @@
+#!/bin/bash
+
+# clean what was left from previous tests
+
+rm -f ./.pt.db
+rm -rf ./protected
+mkdir protected
+touch ./protected/do-not-remove ./protected/should-be-removed ./protected/truth ./protected/perm000 ./protected/perm777 ./protected/should-be-renamed ./protected/do-not-rename
+chmod 777 ./protected/perm777 ./protected/perm000
+echo "Free code, free world." >./protected/motto
+
+mkdir protected/haystack
+for i in {1..100}; do
+  touch "./protected/haystack/hay$i"
+done
+touch ./protected/haystack/needle
+echo "Liberty in every line." >./protected/haystack/needle
+
+rm -rf ./openers
+mkdir openers
+make -C ./opener || (
+  echo "Could not make the opener program."
+  exit 1
+)
+for i in {1..12}; do
+  cp ./opener/opener "./openers/opener$i"
+  ln --symbolic "$(realpath "./openers/opener$i")" "./openers/symlinked_opener$i"
+done
+
+# set up the fake-zenity
+
+PATH="$(realpath ./mock/):$PATH"
+
+# mount the filesystem
+
+echo "Run $(date -u +%Y-%m-%dT%H:%M:%S) "
+if [[ $1 == "--setuid" ]]; then
+  echo "Setting the setuid bit..."
+  echo "root privilieges are required to create a special user and set correct ownership of the executable."
+  id -u icfs &>/dev/null || sudo useradd --system --user-group icfs
+  sudo chown icfs: ../build/icfs && sudo chmod 4777 ../build/icfs
+  chmod g+w . # needed for icfs to be able to create the database
+  echo "Valgrind will not be used due to setuid compatibility issues."
+  ../build/icfs -o default_permissions ./protected ./.pt.db &
+  sleep 1
+elif [[ $1 == "--performance" ]]; then
+  echo "Database protection will not be tested due to the lack of setuid capabilites."
+  echo "To test it, run this script with '--setuid'."
+  echo "valgrind won't be used to make performance measurements more accurate."
+  ../build/icfs -o default_permissions ./protected ./.pt.db &
+  sleep 5
+else
+  echo "Database protection will not be tested due to the lack of setuid capabilites."
+  echo "To test it, run this script with '--setuid'."
+  valgrind --leak-check=full -s ../build/icfs -o default_permissions ./protected ./.pt.db &
+  sleep 5
+fi
+
+#valgrind -s ../build/icfs -o default_permissions ./protected &
+
+echo "[ICFS-TEST]: You may see memory errors from valgrind at this stage. This is normal - memory isn't lost, the libfuse just forked the process."
+
+# WARN: please don't use `>` or `>>` operators. They force **this script** to open the file, **not the program you are trying to run**. This is probably not what you mean when you want to test a specific program's access.
+# WARN: avoid using touch, since it generates errors because setting times is not implemented in icfs **yet**.
+
+# create files
+
+icfs_dialogue --set-fake-response no
+truncate -s 0 ./protected/should-exist-anyway 2>/dev/null &&
+  echo "[ICFS-TEST]: OK" ||
+  echo "[ICFS-TEST]: truncate cannot create protected/should-exist despite access being permitted!" # OK
+
+icfs_dialogue --set-fake-response yes
+truncate -s 0 ./protected/should-exist 2>/dev/null &&
+  echo "[ICFS-TEST]: OK" ||
+  echo "[ICFS-TEST]: truncate cannot create protected/should-exist despite access being permitted!" # OK
+
+# write to files
+
+icfs_dialogue --set-fake-response no
+sed -e 'a\'"Linux is a cancer that attaches itself in an intellectual property sense to everything it touches." "./protected/truth" 2>/dev/null &&
+  echo "[ICFS-TEST]: echo can write to protected/lie despite access being denied!" ||
+  echo "[ICFS-TEST]: OK" # EACCESS
+
+icfs_dialogue --set-fake-response yes
+sed -e 'a\'"Sharing knowledge is the most fundamental act of friendship. Because it is a way you can give something without loosing something." "./protected/truth" 2>/dev/null &&
+  echo "[ICFS-TEST]: OK" ||
+  echo "[ICFS-TEST]: echo cannot write to protected/truth despite access being permitted!" # OK
+
+# Read files
+
+icfs_dialogue --set-fake-response no
+cat ./protected/motto >/dev/null 2>/dev/null &&
+  echo "[ICFS-TEST]: cat can read protected/this-only despite access being denied!" ||
+  echo "[ICFS-TEST]: OK" # EACCESS
+
+icfs_dialogue --set-fake-response yes
+cat ./protected/motto >/dev/null 2>/dev/null &&
+  echo "[ICFS-TEST]: OK" ||
+  echo "[ICFS-TEST]: echo cannot create protected/this-only despite access being permitted!" # "Free code, free world."
+
+# remove files
+
+icfs_dialogue --set-fake-response no
+rm ./protected/do-not-remove >/dev/null 2>/dev/null &&
+  echo "[ICFS-TEST]: rm can unlink protected/do-not-remove despite access being denied!" ||
+  echo "[ICFS-TEST]: OK" # EACCESS
+
+icfs_dialogue --set-fake-response yes
+rm ./protected/should-be-removed >/dev/null 2>/dev/null &&
+  echo "[ICFS-TEST]: OK" ||
+  echo "[ICFS-TEST]: rm cannot unlink protected/should-be-removed despite access being permitted!" # OK
+
+# rename files
+
+icfs_dialogue --set-fake-response no
+mv ./protected/do-not-rename ./protected/terrible-name 2>/dev/null &&
+  echo "[ICFS-TEST]: mv can rename protected/truth despite access being denied!" ||
+  echo "[ICFS-TEST]: OK" # EACCESS
+icfs_dialogue --set-fake-response yes
+mv ./protected/should-be-renamed ./protected/great-name 2>/dev/null &&
+  echo "[ICFS-TEST]: OK" ||
+  echo "[ICFS-TEST]: mv cannot rename should-be-removed to renamed-file despite access being permitted!" # OK
+
+# change permissions
+
+icfs_dialogue --set-fake-response no
+chmod 000 ./protected/perm777 2>/dev/null &&
+  echo "[ICFS-TEST]: chmod can change permissions of protected/perm777 despite access being denied!" ||
+  echo "[ICFS-TEST]: OK" # EACCESS
+icfs_dialogue --set-fake-response yes
+chmod 000 ./protected/perm000 2>/dev/null &&
+  echo "[ICFS-TEST]: OK" ||
+  echo "[ICFS-TEST]: chmod cannot change permissions of protected/perm000 despite access being permitted!" # OK
+
+# test permanent permissions
+
+icfs_dialogue --set-fake-response yes_perm
+openers/opener1 ./protected/motto >/dev/null 2>/dev/null &&
+  echo "[ICFS-TEST]: OK" ||
+  echo "[ICFS-TEST]: openers/opener1 cannot read protected/motto despite access being permitted!" # OK
+
+icfs_dialogue --set-fake-response no # this should be ignored
+openers/opener1 ./protected/motto >/dev/null 2>/dev/null &&
+  echo "[ICFS-TEST]: OK" ||
+  echo "[ICFS-TEST]: openers/opener1 cannot read protected/motto despite access being permitted!" # OK
+
+icfs_dialogue --set-fake-response no # this should be ignored
+openers/symlinked_opener1 ./protected/motto >/dev/null 2>/dev/null &&
+  echo "[ICFS-TEST]: OK" ||
+  echo "[ICFS-TEST]: openers/symlinked_opener1 cannot read protected/motto despite access being permitted!" # OK
+
+icfs_dialogue --set-fake-response no_perm
+openers/opener2 ./protected/motto >/dev/null 2>/dev/null &&
+  echo "[ICFS-TEST]: openers/opener2 can read protected/motto despite access being denied!" ||
+  echo "[ICFS-TEST]: OK" # EACCESS
+
+icfs_dialogue --set-fake-response yes # this should be ignored
+openers/opener2 ./protected/motto >/dev/null 2>/dev/null &&
+  echo "[ICFS-TEST]: openers/opener2 can read protected/motto despite access being denied!" ||
+  echo "[ICFS-TEST]: OK" # EACCESS
+
+icfs_dialogue --set-fake-response yes # this should be ignored
+openers/symlinked_opener2 ./protected/motto >/dev/null 2>/dev/null &&
+  echo "[ICFS-TEST]: openers/symlinked_opener2 can read protected/motto despite access being denied!" ||
+  echo "[ICFS-TEST]: OK" # EACCESS
+
+# test permission globbing
+
+icfs_dialogue --set-fake-response yes
+icfs_dialogue --set-fake-response-filename "/"
+openers/opener3 ./protected/haystack >/dev/null 2>/dev/null &&
+  echo "[ICFS-TEST]: OK" ||
+  echo "[ICFS-TEST]: openers/opener3 cannot read protected/haystack/needle despite access being permitted!" # OK
+
+icfs_dialogue --set-fake-response no
+icfs_dialogue --set-fake-response-filename "/"
+openers/opener4 ./protected/haystack >/dev/null 2>/dev/null &&
+  echo "[ICFS-TEST]: openers/opener4 can read files in protected/haystack despite access being denied!" ||
+  echo "[ICFS-TEST]: OK" # EACCESS
+
+icfs_dialogue --set-fake-response yes_perm
+icfs_dialogue --set-fake-response-filename "/"
+openers/opener5 ./protected/haystack/needle >/dev/null 2>/dev/null &&
+  echo "[ICFS-TEST]: OK" ||
+  echo "[ICFS-TEST]: openers/opener5 cannot read protected/haystack/needle despite access being permitted!" # OK
+
+icfs_dialogue --set-fake-response no # this should be ignored
+openers/opener5 ./protected/haystack >/dev/null 2>/dev/null &&
+  echo "[ICFS-TEST]: OK" ||
+  echo "[ICFS-TEST]: openers/opener5 cannot read files in protected/haystack despite access being permitted!" # OK
+
+icfs_dialogue --set-fake-response no_perm
+icfs_dialogue --set-fake-response-filename "/"
+openers/opener6 ./protected/haystack/needle >/dev/null 2>/dev/null &&
+  echo "[ICFS-TEST]: openers/opener6 can read protected/haystack/needle despite access being denied!" ||
+  echo "[ICFS-TEST]: OK" # EACCESS
+
+icfs_dialogue --set-fake-response yes # this should be ignored
+openers/opener6 ./protected/haystack >/dev/null 2>/dev/null &&
+  echo "[ICFS-TEST]: openers/opener6 can read files in protected/haystack despite access being denied!" ||
+  echo "[ICFS-TEST]: OK" # EACCESS
+
+# test database access
+if [[ $1 == '--setuid' ]]; then
+  if [[ -r "./.pt.db" || -w "./.pt.db" ]]; then
+    echo "[ICFS-TEST]: permanent permissions database is accessible!"
+  else
+    echo "[ICFS-TEST]: OK"
+  fi
+else
+  echo "[ICFS-TEST]: permanent permissions database access was not tested due to the lack of seuid bit setting capabilites. To test this, run the script with '--setuid' flag"
+fi
+
+# performance testing code
+
+RUNS_NUM=500
+if [[ $1 == '--performance' ]]; then
+  icfs_dialogue --set-fake-response yes
+  echo "[ICFS-TEST]: temp permissions"
+  time parallel -j8 ::: "./stress.bash $RUNS_NUM openers/opener7"
+
+  icfs_dialogue --set-fake-response yes_perm
+  echo "[ICFS-TEST]: perm permissions"
+  time parallel -j8 ::: "./stress.bash $RUNS_NUM openers/opener8"
+fi
+
+# unmount
+
+sleep 0.5
+#lsof +f -- $(realpath ./protected)
+umount "$(realpath ./protected)"
+sleep 3
+
+# test the same thing, but without ICFS mounted
+
+if [[ $1 == '--performance' ]]; then
+  echo "[ICFS-TEST]: bare filesystem"
+  time parallel -j8 ::: "./stress.bash $RUNS_NUM openers/opener9"
+fi