Merge pull request #29 from pmillerchip/symlink-fixes

Replace get_link with realpath

4 files changed, 15 insertions, 60 deletions

diff --git a/src/firejail/firejail.h b/src/firejail/firejail.h
index 7eb4786e6..3acaeb6fb 100644
--- a/src/firejail/firejail.h
+++ b/src/firejail/firejail.h
@@ -253,7 +253,6 @@ void logmsg(const char *msg);
 void logargs(int argc, char **argv) ;
 void logerr(const char *msg);
 int copy_file(const char *srcname, const char *destname);
-char *get_link(const char *fname);
 int is_dir(const char *fname);
 int is_link(const char *fname);
 char *line_remove_spaces(const char *buf);
diff --git a/src/firejail/fs_dev.c b/src/firejail/fs_dev.c
index 80bd11582..212b3211c 100644
--- a/src/firejail/fs_dev.c
+++ b/src/firejail/fs_dev.c
@@ -127,30 +127,20 @@ void fs_dev_shm(void) {
                         errExit("mounting /dev/shm");
         }
         else {
-                char *lnk = get_link("/dev/shm");
+                char *lnk = realpath("/dev/shm", NULL);
                 if (lnk) {
-                        // convert a link such as "../shm" into "/shm"
-                        char *lnk2 = lnk;
-                        int cnt = 0;
-                        while (strncmp(lnk2, "../", 3) == 0) {
-                                cnt++;
-                                lnk2 = lnk2 + 3;
-                        }
-                        if (cnt != 0)
-                                lnk2 = lnk + (cnt - 1) * 3 + 2;
-
-                        if (!is_dir(lnk2)) {
+                        if (!is_dir(lnk)) {
                                 // create directory
-                                if (mkdir(lnk2, S_IRWXU|S_IRWXG|S_IRWXO))
+                                if (mkdir(lnk, S_IRWXU|S_IRWXG|S_IRWXO))
                                         errExit("mkdir");
-                                if (chown(lnk2, 0, 0))
+                                if (chown(lnk, 0, 0))
                                         errExit("chown");
-                                if (chmod(lnk2, S_IRWXU|S_IRWXG|S_IRWXO))
+                                if (chmod(lnk, S_IRWXU|S_IRWXG|S_IRWXO))
                                         errExit("chmod");
                         }
                         if (arg_debug)
-                                printf("Mounting tmpfs on %s on behalf of /dev/shm\n", lnk2);
-                        if (mount("tmpfs", lnk2, "tmpfs", MS_NOSUID | MS_STRICTATIME | MS_REC,  "mode=777,gid=0") < 0)
+                                printf("Mounting tmpfs on %s on behalf of /dev/shm\n", lnk);
+                        if (mount("tmpfs", lnk, "tmpfs", MS_NOSUID | MS_STRICTATIME | MS_REC,  "mode=777,gid=0") < 0)
                                 errExit("mounting /var/tmp");
                         free(lnk);
                 }
diff --git a/src/firejail/fs_var.c b/src/firejail/fs_var.c
index 588090c00..9f554f662 100644
--- a/src/firejail/fs_var.c
+++ b/src/firejail/fs_var.c
@@ -240,7 +240,7 @@ void dbg_test_dir(const char *dir) {
                 if (is_dir(dir))
                         printf("%s is a directory\n", dir);
                 if (is_link(dir)) {
-                        char *lnk = get_link(dir);
+                        char *lnk = realpath(dir, NULL);
                         if (lnk) {
                                 printf("%s is a symbolic link to %s\n", dir, lnk);
                                 free(lnk);
@@ -259,30 +259,20 @@ void fs_var_lock(void) {
                         errExit("mounting /lock");
         }
         else {
-                char *lnk = get_link("/var/lock");
+                char *lnk = realpath("/var/lock", NULL);
                 if (lnk) {
-                        // convert a link such as "../shm" into "/shm"
-                        char *lnk2 = lnk;
-                        int cnt = 0;
-                        while (strncmp(lnk2, "../", 3) == 0) {
-                                cnt++;
-                                lnk2 = lnk2 + 3;
-                        }
-                        if (cnt != 0)
-                                lnk2 = lnk + (cnt - 1) * 3 + 2;
-
-                        if (!is_dir(lnk2)) {
+                        if (!is_dir(lnk)) {
                                 // create directory
-                                if (mkdir(lnk2, S_IRWXU|S_IRWXG|S_IRWXO))
+                                if (mkdir(lnk, S_IRWXU|S_IRWXG|S_IRWXO))
                                         errExit("mkdir");
-                                if (chown(lnk2, 0, 0))
+                                if (chown(lnk, 0, 0))
                                         errExit("chown");
-                                if (chmod(lnk2, S_IRWXU|S_IRWXG|S_IRWXO))
+                                if (chmod(lnk, S_IRWXU|S_IRWXG|S_IRWXO))
                                         errExit("chmod");
                         }
                         if (arg_debug)
-                                printf("Mounting tmpfs on %s on behalf of /var/lock\n", lnk2);
-                        if (mount("tmpfs", lnk2, "tmpfs", MS_NOSUID | MS_STRICTATIME | MS_REC,  "mode=777,gid=0") < 0)
+                                printf("Mounting tmpfs on %s on behalf of /var/lock\n", lnk);
+                        if (mount("tmpfs", lnk, "tmpfs", MS_NOSUID | MS_STRICTATIME | MS_REC,  "mode=777,gid=0") < 0)
                                 errExit("mounting /var/lock");
                         free(lnk);
                 }
diff --git a/src/firejail/util.c b/src/firejail/util.c
index 2c50caf17..95409129a 100644
--- a/src/firejail/util.c
+++ b/src/firejail/util.c
@@ -172,30 +172,6 @@ int copy_file(const char *srcname, const char *destname) {
         return 0;
 }
 
-
-char *get_link(const char *fname) {
-        assert(fname);
-        struct stat sb;
-        char *linkname;
-        ssize_t r;
-
-        if (lstat(fname, &sb) == -1)
-                return NULL;
-
-        linkname = malloc(sb.st_size + 1);
-        if (linkname == NULL)
-                return NULL;
-        memset(linkname, 0, sb.st_size + 1);
-
-        r = readlink(fname, linkname, sb.st_size + 1);
-        if (r < 0) {
-                free(linkname);
-                return NULL;
-        }
-        return linkname;
-}
-
-
 // return 1 if the file is a directory
 int is_dir(const char *fname) {
         assert(fname);