net: ensure "socket" backend uses non-blocking fds

There are several code paths in net_init_socket() depending on how the
socket is created: file descriptor passing, UDP multicast, TCP, or UDP.
Some of these support both listen and connect.

Not all code paths set the socket to non-blocking.  This patch addresses
the file descriptor passing and UDP cases which were missing
socket_set_nonblock(fd) calls.

I considered moving socket_set_nonblock(fd) to a central location but it
turns out the code paths are different enough to require non-blocking at
different places.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/net/socket.c b/net/socket.c
index b5c8e659ec..87af1d3d39 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -674,6 +674,7 @@ static int net_socket_udp_init(NetClientState *peer,
         closesocket(fd);
         return -1;
     }
+    qemu_set_nonblock(fd);
 
     s = net_socket_fd_init(peer, model, name, fd, 0);
     if (!s) {
@@ -712,7 +713,11 @@ int net_init_socket(const NetClientOptions *opts, const char *name,
         int fd;
 
         fd = monitor_handle_fd_param(cur_mon, sock->fd);
-        if (fd == -1 || !net_socket_fd_init(peer, "socket", name, fd, 1)) {
+        if (fd == -1) {
+            return -1;
+        }
+        qemu_set_nonblock(fd);
+        if (!net_socket_fd_init(peer, "socket", name, fd, 1)) {
             return -1;
         }
         return 0;