networkd: add basic dbus API

[elogind.git] / src / core / loopback-setup.c

diff --git a/src/core/loopback-setup.c b/src/core/loopback-setup.c
index 0d7d00cfc00eea8109e215c01e028b7aba3160ae..67ce160c1982f9cb7084cc3e9b7898cc6d4c7c64 100644 (file)
--- a/src/core/loopback-setup.c
+++ b/src/core/loopback-setup.c
@@ -27,15 +27,13 @@
 #include <stdlib.h>
 #include <unistd.h>
 
+#include "sd-rtnl.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 +61,15 @@ 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 +83,17 @@ 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;
 }