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;
return 0;
}
-static int check_loopback(void) {
+static bool check_loopback(sd_rtnl *rtnl) {
+ _cleanup_rtnl_message_unref_ sd_rtnl_message *req = NULL, *reply = NULL;
+ unsigned flags;
int r;
- _cleanup_close_ int fd = -1;
- union {
- struct sockaddr sa;
- struct sockaddr_in in;
- } sa = {
- .in.sin_family = AF_INET,
- .in.sin_addr.s_addr = INADDR_LOOPBACK,
- };
-
- /* If we failed to set up the loop back device, check whether
- * it might already be set up */
-
- fd = socket(AF_INET, SOCK_DGRAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0);
- if (fd < 0)
- return -errno;
-
- if (bind(fd, &sa.sa, sizeof(sa.in)) >= 0)
- r = 1;
- else
- r = errno == EADDRNOTAVAIL ? 0 : -errno;
-
- return r;
+
+ r = sd_rtnl_message_new_link(rtnl, &req, RTM_GETLINK, LOOPBACK_IFINDEX);
+ if (r < 0)
+ return false;
+
+ r = sd_rtnl_call(rtnl, req, 0, &reply);
+ if (r < 0)
+ return false;
+
+ r = sd_rtnl_message_link_get_flags(reply, &flags);
+ if (r < 0)
+ return false;
+
+ return flags & IFF_UP;
}
int loopback_setup(void) {
return r;
r = start_loopback(rtnl);
- if (r == -EPERM) {
- if (check_loopback() < 0) {
- log_warning("Failed to configure loopback device: %s",
- strerror(EPERM));
- return -EPERM;
- }
- } else if (r < 0) {
- log_warning("Failed to configure loopback device: %s",
- strerror(-r));
- return r;
- }
+ 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;
}