chiark / gitweb /
unit: use weaker dependencies between mount and device units in --user mode
[elogind.git] / src / core / loopback-setup.c
index 0d7d00c..63b15c1 100644 (file)
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
-#include <sys/socket.h>
 #include <net/if.h>
-#include <asm/types.h>
-#include <netinet/in.h>
-#include <string.h>
 #include <stdlib.h>
-#include <unistd.h>
 
-#include "util.h"
-#include "macro.h"
-#include "loopback-setup.h"
-#include "socket-util.h"
 #include "sd-rtnl.h"
 #include "rtnl-util.h"
-
-/* this is hardcoded in the kernel, so don't look it up */
-#define LOOPBACK_IFINDEX 1
+#include "missing.h"
+#include "loopback-setup.h"
 
 static int start_loopback(sd_rtnl *rtnl) {
         _cleanup_rtnl_message_unref_ sd_rtnl_message *req = NULL;
@@ -63,15 +53,15 @@ static bool check_loopback(sd_rtnl *rtnl) {
 
         r = sd_rtnl_message_new_link(rtnl, &req, RTM_GETLINK, LOOPBACK_IFINDEX);
         if (r < 0)
-                return r;
+                return false;
 
         r = sd_rtnl_call(rtnl, req, 0, &reply);
         if (r < 0)
-                return r;
+                return false;
 
         r = sd_rtnl_message_link_get_flags(reply, &flags);
         if (r < 0)
-                return r;
+                return false;
 
         return flags & IFF_UP;
 }
@@ -85,12 +75,17 @@ int loopback_setup(void) {
                 return r;
 
         r = start_loopback(rtnl);
-        if (r == -EPERM) {
-                if (!check_loopback(rtnl))
-                        return log_warning_errno(EPERM, "Failed to configure loopback device: %m");
-        } else if (r < 0)
-                return log_warning_errno(r, "Failed to configure loopback device: %m");
+        if (r < 0) {
 
+                /* If we lack the permissions to configure the
+                 * loopback device, but we find it to be already
+                 * configured, let's exit cleanly, in order to
+                 * supported unprivileged containers. */
+                if (r == -EPERM && check_loopback(rtnl))
+                        return 0;
+
+                return log_warning_errno(r, "Failed to configure loopback device: %m");
+        }
 
         return 0;
 }