[PATCH v6 1/1] server: Defer listens on addresses currently bound first by another socket.

[Ally Sommers]

From: Ally Sommers

---
 dlls/ws2_32/tests/sock.c |  2 +-
 server/sock.c            | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/dlls/ws2_32/tests/sock.c b/dlls/ws2_32/tests/sock.c
index 31dff1a11c7..1278dfb0fa3 100644
--- a/dlls/ws2_32/tests/sock.c
+++ b/dlls/ws2_32/tests/sock.c
@@ -2298,7 +2298,7 @@ static void test_reuseaddr(void)
         rc = listen(s1, 1);
         ok(!rc, "got error %d.\n", WSAGetLastError());
         rc = listen(s2, 1);
-        todo_wine ok(!rc, "got error %d.\n", WSAGetLastError());
+        ok(!rc, "got error %d.\n", WSAGetLastError());
         rc = connect(s3, tests[i].addr_loopback, tests[i].addrlen);
         ok(!rc, "got error %d.\n", WSAGetLastError());

diff --git a/server/sock.c b/server/sock.c
index ac55a5448f7..80d314946a7 100644
--- a/server/sock.c
+++ b/server/sock.c
@@ -193,6 +193,7 @@ struct bound_addr
     union unix_sockaddr addr;
     int match_any_addr;
     int reuse_count;
+    struct sock *sock;
 };

#define MAX_ICMP_HISTORY_LENGTH 8
@@ -264,6 +265,9 @@ struct sock
     unsigned int        reset : 1;   /* did we get a TCP reset? */
     unsigned int        reuseaddr : 1; /* winsock SO_REUSEADDR option value */
     unsigned int        exclusiveaddruse : 1; /* winsock SO_EXCLUSIVEADDRUSE option value */
+    unsigned int        listen_queued : 1; /* listen() while bound to an in-use address? */
+    int                 listen_backlog; /* stored argument for deferred listen() */
+    struct list         bind_list; /* ordered list of sockets bound to the same address */
 };

static int is_tcp_socket( struct sock *sock )
@@ -397,10 +401,12 @@ static struct bound_addr *register_bound_address( struct sock *sock, const union
             return NULL;
         }
         ++bound_addr->reuse_count;
+        list_add_tail(&bound_addr->sock->bind_list, &sock->bind_list);
     }
     else
     {
         bound_addr->reuse_count = sock->reuseaddr ? 1 : -1;
+        bound_addr->sock = sock;
     }
     return bound_addr;
 }
@@ -1663,7 +1669,28 @@ static int sock_close_handle( struct object *obj, struct process *process, obj_h

if (signaled) complete_async_poll( poll_req, STATUS_SUCCESS );
         }
+
+        list_remove(&sock->bind_list);
+
+        if (sock->bound_addr[0] && sock->bound_addr[0]->sock == sock)
+        {
+            struct sock *new_sock;
+            struct list *next_list_elem = list_next( &sock->bind_list, &sock->bind_list );
+            if (!next_list_elem)
+                goto no_next_socket_or_deferred_listen;
+
+            new_sock = LIST_ENTRY( next_list_elem, struct sock, bind_list );
+            sock->bound_addr[0]->sock = new_sock;
+            if (sock->bound_addr[1])
+                sock->bound_addr[1]->sock = new_sock;
+
+            close( get_unix_fd( sock->fd ) );
+            if (new_sock->listen_queued)
+                if (listen( get_unix_fd( new_sock->fd ), new_sock->listen_backlog ) == -1 && debug_level)
+                    fprintf( stderr, "FIXME: deferred listen threw errno %d (%s)\n", errno, strerror(errno) );
+        }
     }
+no_next_socket_or_deferred_listen:
     return async_close_obj_handle( obj, process, handle );
 }

@@ -1740,6 +1767,8 @@ static struct sock *create_socket(void)
     sock->rcvtimeo = 0;
     sock->sndtimeo = 0;
     sock->icmp_fixup_data_len = 0;
+    sock->listen_queued = 0;
+    sock->listen_backlog = 0;
     sock->bound_addr[0] = sock->bound_addr[1] = NULL;
     init_async_queue( &sock->read_q );
     init_async_queue( &sock->write_q );
@@ -1749,6 +1778,7 @@ static struct sock *create_socket(void)
     init_async_queue( &sock->poll_q );
     memset( sock->errors, 0, sizeof(sock->errors) );
     list_init( &sock->accept_list );
+    list_init( &sock->bind_list );
     return sock;
 }

@@ -2539,12 +2569,20 @@ static void sock_ioctl( struct fd *fd, ioctl_code_t code, struct async *async )
             return;
         }

+        if (sock->bound_addr[0] && sock->bound_addr[0]->sock != sock)
+        {
+            sock->listen_backlog = params->backlog;
+            sock->listen_queued = 1;
+            goto listen_skip_error;
+        }
+
         if (listen( unix_fd, params->backlog ) < 0)
         {
             set_error( sock_get_ntstatus( errno ) );
             return;
         }

+    listen_skip_error:
         sock->state = SOCK_LISTENING;

/* a listening socket can no longer be accepted into */