1 files changed, 27 insertions, 6 deletions

diff --git a/shared/systemd/src/basic/socket-util.c b/shared/systemd/src/basic/socket-util.c
index b98b0461..b822ed03 100644
--- a/shared/systemd/src/basic/socket-util.c
+++ b/shared/systemd/src/basic/socket-util.c
@@ -81,7 +81,7 @@ int socket_address_parse(SocketAddress *a, const char *s) {
 
                 errno = 0;
                 if (inet_pton(AF_INET6, n, &a->sockaddr.in6.sin6_addr) <= 0)
-                        return errno > 0 ? -errno : -EINVAL;
+                        return errno_or_else(EINVAL);
 
                 e++;
                 if (*e != ':')
@@ -1224,17 +1224,34 @@ fallback:
 }
 
 #if 0 /* NM_IGNORED */
+/* Put a limit on how many times will attempt to call accept4(). We loop
+ * only on "transient" errors, but let's make sure we don't loop forever. */
+#define MAX_FLUSH_ITERATIONS 1024
+
 int flush_accept(int fd) {
 
         struct pollfd pollfd = {
                 .fd = fd,
                 .events = POLLIN,
         };
-        int r;
+        int r, b;
+        socklen_t l = sizeof(b);
 
-        /* Similar to flush_fd() but flushes all incoming connection by accepting them and immediately closing them. */
+        /* Similar to flush_fd() but flushes all incoming connections by accepting and immediately closing
+         * them. */
 
-        for (;;) {
+        if (getsockopt(fd, SOL_SOCKET, SO_ACCEPTCONN, &b, &l) < 0)
+                return -errno;
+
+        assert(l == sizeof(b));
+        if (!b) /* Let's check if this socket accepts connections before calling accept(). accept4() can
+                 * return EOPNOTSUPP if the fd is not a listening socket, which we should treat as a fatal
+                 * error, or in case the incoming TCP connection triggered a network issue, which we want to
+                 * treat as a transient error. Thus, let's rule out the first reason for EOPNOTSUPP early, so
+                 * we can loop safely on transient errors below. */
+                return -ENOTTY;
+
+        for (unsigned iteration = 0;; iteration++) {
                 int cfd;
 
                 r = poll(&pollfd, 1, 0);
@@ -1247,6 +1264,10 @@ int flush_accept(int fd) {
                 if (r == 0)
                         return 0;
 
+                if (iteration >= MAX_FLUSH_ITERATIONS)
+                        return log_debug_errno(SYNTHETIC_ERRNO(EBUSY),
+                                               "Failed to flush connections within " STRINGIFY(MAX_FLUSH_ITERATIONS) " iterations.");
+
                 cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC);
                 if (cfd < 0) {
                         if (errno == EAGAIN)
@@ -1374,7 +1395,7 @@ int socket_bind_to_ifname(int fd, const char *ifname) {
 }
 
 int socket_bind_to_ifindex(int fd, int ifindex) {
-        char ifname[IFNAMSIZ] = "";
+        char ifname[IF_NAMESIZE + 1];
 
         assert(fd >= 0);
 
@@ -1392,7 +1413,7 @@ int socket_bind_to_ifindex(int fd, int ifindex) {
                 return -errno;
 
         /* Fall back to SO_BINDTODEVICE on kernels < 5.0 which didn't have SO_BINDTOIFINDEX */
-        if (!if_indextoname(ifindex, ifname))
+        if (!format_ifname(ifindex, ifname))
                 return -errno;
 
         return socket_bind_to_ifname(fd, ifname);