diff --git a/src/firecfg/Makefile.in b/src/firecfg/Makefile.in index b6dbb039da7..e860643dfcd 100644 --- a/src/firecfg/Makefile.in +++ b/src/firecfg/Makefile.in @@ -2,11 +2,11 @@ all: firecfg include ../common.mk -%.o : %.c $(H_FILE_LIST) ../include/common.h ../include/euid_common.h ../include/libnetlink.h ../include/pid.h +%.o : %.c $(H_FILE_LIST) ../include/common.h ../include/euid_common.h ../include/libnetlink.h ../include/firejail_user.h ../include/pid.h $(CC) $(CFLAGS) $(EXTRA_CFLAGS) $(INCLUDE) -c $< -o $@ -firecfg: $(OBJS) ../lib/common.o - $(CC) $(LDFLAGS) -o $@ $(OBJS) ../lib/common.o $(LIBS) $(EXTRA_LDFLAGS) +firecfg: $(OBJS) ../lib/common.o ../lib/firejail_user.o + $(CC) $(LDFLAGS) -o $@ $(OBJS) ../lib/common.o ../lib/firejail_user.o $(LIBS) $(EXTRA_LDFLAGS) clean:; rm -f *.o firecfg *.gcov *.gcda *.gcno diff --git a/src/firecfg/main.c b/src/firecfg/main.c index e636dc385b2..a54607aece7 100644 --- a/src/firecfg/main.c +++ b/src/firecfg/main.c @@ -19,6 +19,7 @@ */ #include "firecfg.h" +#include "../include/firejail_user.h" int arg_debug = 0; static char *usage_str = @@ -29,6 +30,7 @@ static char *usage_str = "The symbolic links are placed in /usr/local/bin. For more information, see\n" "DESKTOP INTEGRATION section in man 1 firejail.\n\n" "Usage: firecfg [OPTIONS]\n\n" + " --add-users user [user] - add the users to Firejail access database\n" " --clean - remove all firejail symbolic links.\n\n" " --debug - print debug messages.\n\n" " --fix - fix .desktop files.\n\n" @@ -315,6 +317,19 @@ int main(int argc, char **argv) { sound(); return 0; } + else if (strcmp(argv[i], "--add-users") == 0) { + int j; + if (getuid() != 0) { + fprintf(stderr, "Error: you need to be root to use this option\n"); + exit(1); + } + + for (j = i + 1; j < argc; j++) { + printf("Adding user %s to Firejail access database in %s/firejail.users\n", argv[j], SYSCONFDIR); + firejail_user_add(argv[j]); + } + return 0; + } else { fprintf(stderr, "Error: invalid command line option\n"); usage(); @@ -353,7 +368,7 @@ int main(int argc, char **argv) { - // switch to the local user, and fix desktop files + // user setup char *user = getlogin(); if (!user) { user = getenv("SUDO_USER"); @@ -362,6 +377,13 @@ int main(int argc, char **argv) { } } + // add user to firejail access database + if (user) { + printf("\nAdding user %s to Firejail access database in %s/firejail.users\n", user, SYSCONFDIR); + firejail_user_add(user); + } + + // switch to the local user, and fix desktop files if (user) { // find home directory struct passwd *pw = getpwnam(user); diff --git a/src/firejail/Makefile.in b/src/firejail/Makefile.in index 9bd2f9c2268..48d985d73ec 100644 --- a/src/firejail/Makefile.in +++ b/src/firejail/Makefile.in @@ -2,11 +2,11 @@ all: firejail include ../common.mk -%.o : %.c $(H_FILE_LIST) ../include/common.h ../include/euid_common.h ../include/pid.h ../include/seccomp.h ../include/syscall.h +%.o : %.c $(H_FILE_LIST) ../include/common.h ../include/euid_common.h ../include/pid.h ../include/seccomp.h ../include/syscall.h ../include/firejail_user.h $(CC) $(CFLAGS) $(EXTRA_CFLAGS) $(INCLUDE) -c $< -o $@ -firejail: $(OBJS) ../lib/libnetlink.o ../lib/common.o ../lib/ldd_utils.o - $(CC) $(LDFLAGS) -o $@ $(OBJS) ../lib/common.o ../lib/ldd_utils.o $(LIBS) $(EXTRA_LDFLAGS) +firejail: $(OBJS) ../lib/libnetlink.o ../lib/common.o ../lib/ldd_utils.o ../lib/firejail_user.o + $(CC) $(LDFLAGS) -o $@ $(OBJS) ../lib/common.o ../lib/ldd_utils.o ../lib/firejail_user.o $(LIBS) $(EXTRA_LDFLAGS) clean:; rm -f *.o firejail *.gcov *.gcda *.gcno diff --git a/src/firejail/main.c b/src/firejail/main.c index f34d2eb797b..e676bbd7c95 100644 --- a/src/firejail/main.c +++ b/src/firejail/main.c @@ -19,6 +19,7 @@ */ #include "firejail.h" #include "../include/pid.h" +#include "../include/firejail_user.h" #define _GNU_SOURCE #include #include @@ -229,6 +230,15 @@ static void init_cfg(int argc, char **argv) { } cfg.cwd = getcwd(NULL, 0); + // chack user database + if (!firejail_user_check(cfg.username)) { + fprintf(stderr, "Error: the user is not allowed to use Firejail. " + "Please add the user in %s/firejail.users file, " + "either by running \"sudo firecfg\", or by editing the file directly." + "See \"man firejail-users\" for more details.\n", SYSCONFDIR); + exit(1); + } + // initialize random number generator sandbox_pid = getpid(); time_t t = time(NULL); @@ -830,7 +840,6 @@ int main(int argc, char **argv) { int lockfd_directory = -1; int option_cgroup = 0; int custom_profile = 0; // custom profile loaded - atexit(clear_atexit); // drop permissions by default and rise them when required EUID_INIT(); @@ -844,9 +853,11 @@ int main(int argc, char **argv) { if (check_arg(argc, argv, "--quiet", 1)) arg_quiet = 1; + // cleanup at exit + EUID_ROOT(); + atexit(clear_atexit); // build /run/firejail directory structure - EUID_ROOT(); preproc_build_firejail_dir(); char *container_name = getenv("container"); if (!container_name || strcmp(container_name, "firejail")) { diff --git a/src/include/firejail_user.h b/src/include/firejail_user.h new file mode 100644 index 00000000000..a7d30225ef9 --- /dev/null +++ b/src/include/firejail_user.h @@ -0,0 +1,30 @@ +/* + * Copyright (C) 2014-2018 Firejail Authors + * + * This file is part of firejail project + * + * 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. + */ +#ifndef FIREJAIL_USER_H +#define FIREJAIL_USER_H + + +// returns 1 if the user is found in the database or if the database was not created +int firejail_user_check(const char *name); + +// add a user to the database +void firejail_user_add(const char *name); + +#endif diff --git a/src/lib/firejail_user.c b/src/lib/firejail_user.c new file mode 100644 index 00000000000..5d92aa1332f --- /dev/null +++ b/src/lib/firejail_user.c @@ -0,0 +1,115 @@ +/* + * Copyright (C) 2014-2018 Firejail Authors + * + * This file is part of firejail project + * + * 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. + */ + +// +// Firejail access database inplementation +// +// The database is a simple list of users allowed to run firejail SUID executable +// It is usually stored in /etc/firejail/firejail.users +// One username per line in the file + +#include "../include/common.h" +#include +#include + +#define MAXBUF 4098 +static inline char *get_fname(void) { + char *fname; + if (asprintf(&fname, "%s/firejail.users", SYSCONFDIR) == -1) + errExit("asprintf"); + return fname; +} + +// returns 1 if the user is found in the database or if the database was not created +int firejail_user_check(const char *name) { + assert(name); + + // root allowed by default + if (strcmp(name, "root") == 0) + return 1; + + // check file existence + char *fname = get_fname(); + if (access(fname, F_OK)) { + free(fname); + return 1; // assume the user doesn't care about access checking + } + + FILE *fp = fopen(fname, "r"); + free(fname); + if (!fp) + return 0; + + char buf[MAXBUF]; + while (fgets(buf, MAXBUF, fp)) { + // lines starting with # are comments + if (*buf == '#') + continue; + + // remove \n + char *ptr = strchr(buf, '\n'); + if (ptr) + *ptr = '\0'; + + // compare + if (strcmp(buf, name) == 0) { + fclose(fp); + return 1; + } + } + + fclose(fp); + return 0; +} + +// add a user to the database +void firejail_user_add(const char *name) { + assert(name); + + // is this a real user? + struct passwd *pw = getpwnam(name); + if (!pw) { + fprintf(stderr, "Error: user %s not found on this system.\n", name); + return; + } + + // check the user is not already in the database + char *fname = get_fname(); + assert(fname); + if (access(fname, F_OK) == 0) { + if (firejail_user_check(name)) { + printf("User %s already in the database\n", name); + return; + } + } + + printf("%s created\n", fname); + FILE *fp = fopen(fname, "a+"); + if (!fp) { + fprintf(stderr, "Error: cannot open %s\n", fname); + perror("fopen"); + free(fname); + return; + } + free(fname); + + fprintf(fp, "%s\n", name); + fclose(fp); +}