scripts: set CRIU_IMAGE_DIR when running scripts

When doing a restore for LXC, we store some other metadata (which bridge a veth
was on) in the image directory so that the restore script can correctly unlock
a network device and attach it to the right interface. This patch is needed so
that the script can find this metadata.
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

util.c

@@ -460,6 +460,7 @@ int run_scripts(char *action)
 {
 	struct script *script;
 	int ret = 0;
+	char image_dir[PATH_MAX];
 
 	pr_debug("Running %s scripts\n", action);
 
@@ -468,6 +469,12 @@ int run_scripts(char *action)
 		return -1;
 	}
 
+	sprintf(image_dir, "/proc/%ld/fd/%d", (long) getpid(), get_service_fd(IMG_FD_OFF));
+	if (setenv("CRTOOLS_IMAGE_DIR", image_dir, 1)) {
+		pr_perror("Can't set CRTOOLS_IMAGE_DIR=%s", image_dir);
+		return -1;
+	}
+
 	list_for_each_entry(script, &opts.scripts, node) {
 		if (script->path == SCRIPT_RPC_NOTIFY) {
 			pr_debug("\tRPC\n");