active: rework make_socket_fd() to be based on socket_address_listen()

Among other things this makes sure we set SO_REUSEADDR which is
immensely useful.

src/shared/socket-label.c

@@ -41,6 +41,7 @@
 
 int socket_address_listen(
                 const SocketAddress *a,
+                int flags,
                 int backlog,
                 SocketAddressBindIPv6Only only,
                 const char *bind_to_device,
@@ -48,27 +49,31 @@ int socket_address_listen(
                 bool transparent,
                 mode_t directory_mode,
                 mode_t socket_mode,
-                const char *label,
-                int *ret) {
+                const char *label) {
+
+        _cleanup_close_ int fd = -1;
+        int r, one;
 
-        int r, fd, one;
         assert(a);
-        assert(ret);
 
-        if ((r = socket_address_verify(a)) < 0)
+        r = socket_address_verify(a);
+        if (r < 0)
                 return r;
 
         if (socket_address_family(a) == AF_INET6 && !socket_ipv6_is_supported())
                 return -EAFNOSUPPORT;
 
-        r = label_socket_set(label);
-        if (r < 0)
-                return r;
+        if (label) {
+                r = label_socket_set(label);
+                if (r < 0)
+                        return r;
+        }
 
-        fd = socket(socket_address_family(a), a->type | SOCK_NONBLOCK | SOCK_CLOEXEC, a->protocol);
+        fd = socket(socket_address_family(a), a->type | flags, a->protocol);
         r = fd < 0 ? -errno : 0;
 
-        label_socket_clear();
+        if (label)
+                label_socket_clear();
 
         if (r < 0)
                 return r;
@@ -77,13 +82,13 @@ int socket_address_listen(
                 int flag = only == SOCKET_ADDRESS_IPV6_ONLY;
 
                 if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &flag, sizeof(flag)) < 0)
-                        goto fail;
+                        return -errno;
         }
 
         if (socket_address_family(a) == AF_INET || socket_address_family(a) == AF_INET6) {
                 if (bind_to_device)
                         if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, bind_to_device, strlen(bind_to_device)+1) < 0)
-                                goto fail;
+                                return -errno;
 
                 if (free_bind) {
                         one = 1;
@@ -100,7 +105,7 @@ int socket_address_listen(
 
         one = 1;
         if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) < 0)
-                goto fail;
+                return -errno;
 
         if (socket_address_family(a) == AF_UNIX && a->sockaddr.un.sun_path[0] != 0) {
                 mode_t old_mask;
@@ -108,7 +113,7 @@ int socket_address_listen(
                 /* Create parents */
                 mkdir_parents_label(a->sockaddr.un.sun_path, directory_mode);
 
-                /* Enforce the right access mode for the socket*/
+                /* Enforce the right access mode for the socket */
                 old_mask = umask(~ socket_mode);
 
                 /* Include the original umask in our mask */
@@ -127,17 +132,14 @@ int socket_address_listen(
                 r = bind(fd, &a->sockaddr.sa, a->size);
 
         if (r < 0)
-                goto fail;
+                return -errno;
 
         if (socket_address_can_accept(a))
                 if (listen(fd, backlog) < 0)
-                        goto fail;
+                        return -errno;
 
-        *ret = fd;
-        return 0;
+        r = fd;
+        fd = -1;
 
-fail:
-        r = -errno;
-        close_nointr_nofail(fd);
         return r;
 }