net: inet_connect(), inet_connect_opts(): add in_progress argument

It's used to indicate the special case where a valid file-descriptor
is returned (ie. success) but the connection can't be completed
w/o blocking.

This is needed because QERR_SOCKET_CONNECT_IN_PROGRESS is not
treated like an error and a future commit will drop it.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>

migration-tcp.c

@@ -86,7 +86,7 @@ int tcp_start_outgoing_migration(MigrationState *s, const char *host_port,
     s->write = socket_write;
     s->close = tcp_close;
 
-    s->fd = inet_connect(host_port, false, errp);
+    s->fd = inet_connect(host_port, false, NULL, errp);
 
     if (!error_is_set(errp)) {
         migrate_fd_connect(s);

nbd.c

@@ -162,7 +162,7 @@ int tcp_socket_outgoing(const char *address, uint16_t port)
 
 int tcp_socket_outgoing_spec(const char *address_and_port)
 {
-    return inet_connect(address_and_port, true, NULL);
+    return inet_connect(address_and_port, true, NULL, NULL);
 }
 
 int tcp_socket_incoming(const char *address, uint16_t port)

qemu-char.c

@@ -2446,7 +2446,7 @@ static CharDriverState *qemu_chr_open_socket(QemuOpts *opts)
         if (is_listen) {
             fd = inet_listen_opts(opts, 0, NULL);
         } else {
-            fd = inet_connect_opts(opts, NULL);
+            fd = inet_connect_opts(opts, NULL, NULL);
         }
     }
     if (fd < 0) {

qemu-sockets.c

@@ -209,7 +209,7 @@ listen:
     return slisten;
 }
 
-int inet_connect_opts(QemuOpts *opts, Error **errp)
+int inet_connect_opts(QemuOpts *opts, bool *in_progress, Error **errp)
 {
     struct addrinfo ai,*res,*e;
     const char *addr;
@@ -224,6 +224,10 @@ int inet_connect_opts(QemuOpts *opts, Error **errp)
     ai.ai_family = PF_UNSPEC;
     ai.ai_socktype = SOCK_STREAM;
 
+    if (in_progress) {
+        *in_progress = false;
+    }
+
     addr = qemu_opt_get(opts, "host");
     port = qemu_opt_get(opts, "port");
     block = qemu_opt_get_bool(opts, "block", 0);
@@ -277,6 +281,10 @@ int inet_connect_opts(QemuOpts *opts, Error **errp)
   #else
         if (!block && (rc == -EINPROGRESS)) {
   #endif
+            if (in_progress) {
+                *in_progress = true;
+            }
+
             error_set(errp, QERR_SOCKET_CONNECT_IN_PROGRESS);
         } else if (rc < 0) {
             if (NULL == e->ai_next)
@@ -487,7 +495,7 @@ int inet_listen(const char *str, char *ostr, int olen,
     return sock;
 }
 
-int inet_connect(const char *str, bool block, Error **errp)
+int inet_connect(const char *str, bool block, bool *in_progress, Error **errp)
 {
     QemuOpts *opts;
     int sock = -1;
@@ -497,7 +505,7 @@ int inet_connect(const char *str, bool block, Error **errp)
         if (block) {
             qemu_opt_set(opts, "block", "on");
         }
-        sock = inet_connect_opts(opts, errp);
+        sock = inet_connect_opts(opts, in_progress, errp);
     } else {
         error_set(errp, QERR_SOCKET_CREATE_FAILED);
     }

qemu_socket.h

@@ -42,8 +42,8 @@ int send_all(int fd, const void *buf, int len1);
 int inet_listen_opts(QemuOpts *opts, int port_offset, Error **errp);
 int inet_listen(const char *str, char *ostr, int olen,
                 int socktype, int port_offset, Error **errp);
-int inet_connect_opts(QemuOpts *opts, Error **errp);
-int inet_connect(const char *str, bool block, Error **errp);
+int inet_connect_opts(QemuOpts *opts, bool *in_progress, Error **errp);
+int inet_connect(const char *str, bool block, bool *in_progress, Error **errp);
 int inet_dgram_opts(QemuOpts *opts);
 const char *inet_strfamily(int family);
 

ui/vnc.c

@@ -3061,7 +3061,7 @@ int vnc_display_open(DisplayState *ds, const char *display)
         if (strncmp(display, "unix:", 5) == 0)
             vs->lsock = unix_connect(display+5);
         else
-            vs->lsock = inet_connect(display, true, NULL);
+            vs->lsock = inet_connect(display, true, NULL, NULL);
         if (-1 == vs->lsock) {
             g_free(vs->display);
             vs->display = NULL;