appimage support

4 files changed, 123 insertions, 3 deletions

diff --git a/src/firejail/appimage.c b/src/firejail/appimage.c
new file mode 100644
index 000000000..e25d50a2d
--- /dev/null
+++ b/src/firejail/appimage.c
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2014-2016 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.
+*/
+// http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=770fe30a46a12b6fb6b63fbe1737654d28e84844
+// sudo mount -o loop krita-3.0-x86_64.appimage mnt
+
+#include "firejail.h"
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mount.h>
+#include <fcntl.h>
+#include <linux/loop.h>
+
+
+
+char *appimage_set(const char *appimage_path) {
+        assert(appimage_path);
+        EUID_ASSERT();
+        
+        // check appimage_path
+        if (access(appimage_path, R_OK) == -1) {
+                fprintf(stderr, "Error: cannot access AppImage file\n");
+                exit(1);
+        }
+        
+        EUID_ROOT();
+        
+        // find or allocate a free loop device to use
+        int cfd = open("/dev/loop-control", O_RDWR);
+        int devnr = ioctl(cfd, LOOP_CTL_GET_FREE);
+        if (devnr == -1) {
+                fprintf(stderr, "Error: cannot allocate a new loopback device\n");
+                exit(1);
+        }
+        close(cfd);
+        char *devloop;
+        if (asprintf(&devloop, "/dev/loop%d", devnr) == -1)
+                errExit("asprintf");
+                
+        int ffd = open(appimage_path, O_RDONLY|O_CLOEXEC);
+        int lfd = open(devloop, O_RDONLY);
+        if (ioctl(lfd, LOOP_SET_FD, ffd) == -1) {
+                fprintf(stderr, "Error: cannot configure the loopback device\n");
+                exit(1);
+        }
+        close(lfd);
+        close(ffd);
+        
+        char dirname[] = "/tmp/firejail-mnt-XXXXXX";
+        char *mntdir =  strdup(mkdtemp(dirname));
+        if (mntdir == NULL) {
+                fprintf(stderr, "Error: cannot create temporary directory\n");
+                exit(1);
+        }
+        mkdir(mntdir, 755);
+        chown(mntdir, getuid(), getgid());
+        chmod(mntdir, 755);
+
+        char *mode;
+        if (asprintf(&mode, "mode=755,uid=%d,gid=%d", getuid(), getgid()) == -1)
+                errExit("asprintf");
+
+        if (mount(devloop, mntdir, "iso9660",MS_MGC_VAL|MS_RDONLY,  mode) < 0)
+                errExit("mounting appimage");
+
+        if (arg_debug)
+                printf("appimage mounted on %s\n", mntdir);
+        EUID_USER();
+        
+        // build new command line
+        if (asprintf(&cfg.command_line, "%s/AppRun", mntdir) == -1)
+                errExit("asprintf");
+        
+        free(devloop);
+        free(mode);
+        
+        return mntdir;
+}
diff --git a/src/firejail/firejail.h b/src/firejail/firejail.h
index b0a3ac90d..00674c047 100644
--- a/src/firejail/firejail.h
+++ b/src/firejail/firejail.h
@@ -575,6 +575,8 @@ int checkcfg(int val);
 void fs_rdwr_add(const char *path);
 void fs_rdwr(void);
 
+// appimage.c
+char *appimage_set(const char *appimage_path);
 
 #endif
 
diff --git a/src/firejail/main.c b/src/firejail/main.c
index 0c843de9c..c2ac4a3fa 100644
--- a/src/firejail/main.c
+++ b/src/firejail/main.c
@@ -107,6 +107,7 @@ char *fullargv[MAX_ARGS];			// expanded argv for restricted shell
 int fullargc = 0;
 static pid_t child = 0;
 pid_t sandbox_pid;
+static char *appimage_mntdir = NULL;
 
 static void set_name_file(pid_t pid);
 static void delete_name_file(pid_t pid);
@@ -129,7 +130,12 @@ static void myexit(int rv) {
         // delete sandbox files in shared memory
         EUID_ROOT();
         clear_run_files(sandbox_pid);
-        
+        if (appimage_mntdir) {
+                umount2(appimage_mntdir, MNT_FORCE);
+                rmdir(appimage_mntdir);
+                free(appimage_mntdir);
+        }
+                
         exit(rv); 
 }
 
@@ -701,6 +707,7 @@ int main(int argc, char **argv) {
 #ifdef HAVE_SECCOMP
         int highest_errno = errno_highest_nr();
 #endif
+        int arg_appimage = 0;
 
         // drop permissions by default and rise them when required
         EUID_INIT();
@@ -1400,7 +1407,7 @@ int main(int argc, char **argv) {
                 }
                 else if (strncmp(argv[i], "--env=", 6) == 0)
                         env_store(argv[i] + 6);
-                else if (strncmp(argv[i], "--nosound", 9) == 0) {
+                else if (strcmp(argv[i], "--nosound") == 0) {
                         arg_nosound = 1;
                         arg_private_dev = 1;
                 }
@@ -1766,6 +1773,8 @@ int main(int argc, char **argv) {
                 //*************************************
                 // command
                 //*************************************
+                else if (strcmp(argv[i], "--appimage") == 0)
+                        arg_appimage = 1;
                 else if (strcmp(argv[i], "--csh") == 0) {
                         if (arg_shell_none) {
                         
@@ -1847,7 +1856,13 @@ int main(int argc, char **argv) {
                         }
                         
                         // we have a program name coming
-                        extract_command_name(i, argv);
+                        if (arg_appimage) {
+                                cfg.command_name = strdup(argv[i]);
+                                if (!cfg.command_name)
+                                        errExit("strdup");
+                        }
+                        else
+                                extract_command_name(i, argv);
                         prog_index = i;
                         break;
                 }
@@ -1900,6 +1915,13 @@ int main(int argc, char **argv) {
                 cfg.window_title = "/bin/bash";
                 cfg.command_name = "bash";
         }
+        else if (arg_appimage) {
+                if (arg_debug)
+                        printf("Configuring appimage environment\n");
+                appimage_mntdir = appimage_set(cfg.command_name);
+                cfg.window_title = "appimage";
+                //todo: set window title
+        }
         else {
                 // calculate the length of the command
                 int i;
@@ -1939,6 +1961,7 @@ int main(int argc, char **argv) {
         assert(cfg.command_name);
         if (arg_debug)
                 printf("Command name #%s#\n", cfg.command_name);
+                
                                 
         // load the profile
         if (!arg_noprofile) {
diff --git a/src/firejail/usage.c b/src/firejail/usage.c
index 45bf2e3b1..d2f7d9460 100644
--- a/src/firejail/usage.c
+++ b/src/firejail/usage.c
@@ -34,6 +34,7 @@ void usage(void) {
         printf("\n");
         printf("Options:\n\n");
         printf("    -- - signal the end of options and disables further option processing.\n\n");
+        printf("    --appimage - sandbox an AppImage application\n\n");
 #ifdef HAVE_NETWORK     
         printf("    --bandwidth=name|pid - set  bandwidth  limits  for  the sandbox identified\n");
         printf("\tby name or PID, see Traffic Shaping section fo more details.\n\n");