1 files changed, 28 insertions, 29 deletions

diff --git a/src/firejail/fs.c b/src/firejail/fs.c
index 5b8093885..c38317371 100644
--- a/src/firejail/fs.c
+++ b/src/firejail/fs.c
@@ -82,30 +82,6 @@ void fs_build_mnt_dir(void) {
         }
 }
 
-// build /tmp/firejail/overlay directory
-void fs_build_overlay_dir(void) {
-        struct stat s;
-        fs_build_firejail_dir();
-        
-        // create /tmp/firejail directory
-        if (stat(OVERLAY_DIR, &s)) {
-                if (arg_debug)
-                        printf("Creating %s directory\n", MNT_DIR);
-                /* coverity[toctou] */
-                int rv = mkdir(OVERLAY_DIR, S_IRWXU | S_IRWXG | S_IRWXO);
-                if (rv == -1)
-                        errExit("mkdir");       
-                if (chown(OVERLAY_DIR, 0, 0) < 0)
-                        errExit("chown");
-                if (chmod(OVERLAY_DIR, S_IRWXU  | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH) < 0)
-                        errExit("chmod");
-        }
-}
-
-
-
-
-
 //***********************************************
 // process profile file
 //***********************************************
@@ -629,8 +605,25 @@ void fs_overlayfs(void) {
         if (chmod(oroot, S_IRWXU  | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH) < 0)
                 errExit("chmod");
 
+        char *basedir = MNT_DIR;
+        if (arg_overlay_keep) {
+                // check the directory exists
+                struct stat s;
+                if (stat("/myoverlay", &s) == -1) {
+                        fprintf(stderr, "Error: overlay directory should already exist\n");
+                        exit(1);
+                }
+
+                // set base for working and diff directories
+                basedir = cfg.overlay_dir;
+                if (mkdir(basedir, S_IRWXU | S_IRWXG | S_IRWXO) != 0) {
+                        fprintf(stderr, "Error: cannot create overlay directory\n");
+                        exit(1);
+                }
+        }
+
         char *odiff;
-        if(asprintf(&odiff, "%s/odiff", MNT_DIR) == -1)
+        if(asprintf(&odiff, "%s/odiff", basedir) == -1)
                 errExit("asprintf");
         if (mkdir(odiff, S_IRWXU | S_IRWXG | S_IRWXO))
                 errExit("mkdir");
@@ -638,9 +631,9 @@ void fs_overlayfs(void) {
                 errExit("chown");
         if (chmod(odiff, S_IRWXU  | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH) < 0)
                 errExit("chmod");
-
+        
         char *owork;
-        if(asprintf(&owork, "%s/owork", MNT_DIR) == -1)
+        if(asprintf(&owork, "%s/owork", basedir) == -1)
                 errExit("asprintf");
         if (mkdir(owork, S_IRWXU | S_IRWXG | S_IRWXO))
                 errExit("mkdir");
@@ -648,12 +641,16 @@ void fs_overlayfs(void) {
                 errExit("chown");
         if (chmod(owork, S_IRWXU  | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH) < 0)
                 errExit("chmod");
-
+        
         // mount overlayfs
         if (arg_debug)
                 printf("Mounting OverlayFS\n");
         char *option;
         if (oldkernel) { // old Ubuntu/OpenSUSE kernels
+                if (arg_overlay_keep) {
+                        fprintf(stderr, "Error: option --overlay= not available for kernels older than 3.18\n");
+                        exit(1);
+                }
                 if (asprintf(&option, "lowerdir=/,upperdir=%s", odiff) == -1)
                         errExit("asprintf");
                 if (mount("overlayfs", oroot, "overlayfs", MS_MGC_VAL, option) < 0)
@@ -662,10 +659,12 @@ void fs_overlayfs(void) {
         else { // kernel 3.18 or newer
                 if (asprintf(&option, "lowerdir=/,upperdir=%s,workdir=%s", odiff, owork) == -1)
                         errExit("asprintf");
+//printf("option #%s#\n", option);                      
                 if (mount("overlay", oroot, "overlay", MS_MGC_VAL, option) < 0)
                         errExit("mounting overlayfs");
         }
-
+        printf("OverlayFS configured in %s directory\n", basedir);
+        
         // mount-bind dev directory
         if (arg_debug)
                 printf("Mounting /dev\n");