qemu-sockets: Add error to non-blocking connect handler

An error value here would be quite handy and more consistent
with the rest of the code.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
[Make sure SO_ERROR value is passed to error_setg_errno. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

include/qemu/sockets.h

@@ -47,7 +47,7 @@ int recv_all(int fd, void *buf, int len1, bool single_read);
 /* callback function for nonblocking connect
  * valid fd on success, negative error code on failure
  */
-typedef void NonBlockingConnectHandler(int fd, void *opaque);
+typedef void NonBlockingConnectHandler(int fd, Error *errp, void *opaque);
 
 InetSocketAddress *inet_parse(const char *str, Error **errp);
 int inet_listen_opts(QemuOpts *opts, int port_offset, Error **errp);

migration-tcp.c

@@ -33,12 +33,12 @@
     do { } while (0)
 #endif
 
-static void tcp_wait_for_connect(int fd, void *opaque)
+static void tcp_wait_for_connect(int fd, Error *err, void *opaque)
 {
     MigrationState *s = opaque;
 
     if (fd < 0) {
-        DPRINTF("migrate connect error\n");
+        DPRINTF("migrate connect error: %s\n", error_get_pretty(err));
         s->file = NULL;
         migrate_fd_error(s);
     } else {

migration-unix.c

@@ -33,12 +33,12 @@
     do { } while (0)
 #endif
 
-static void unix_wait_for_connect(int fd, void *opaque)
+static void unix_wait_for_connect(int fd, Error *err, void *opaque)
 {
     MigrationState *s = opaque;
 
     if (fd < 0) {
-        DPRINTF("migrate connect error\n");
+        DPRINTF("migrate connect error: %s\n", error_get_pretty(err));
         s->file = NULL;
         migrate_fd_error(s);
     } else {

qemu-char.c

@@ -3042,11 +3042,13 @@ static void qemu_chr_finish_socket_connection(CharDriverState *chr, int fd)
     }
 }
 
-static void qemu_chr_socket_connected(int fd, void *opaque)
+static void qemu_chr_socket_connected(int fd, Error *err, void *opaque)
 {
     CharDriverState *chr = opaque;
 
     if (fd < 0) {
+        error_report("Unable to connect to char device %s: %s",
+                     chr->label, error_get_pretty(err));
         qemu_chr_socket_restart_timer(chr);
         return;
     }
@@ -4079,7 +4081,8 @@ static gboolean socket_reconnect_timeout(gpointer opaque)
     }
 
     if (!qemu_chr_open_socket_fd(chr, &err)) {
-        error_report("Unable to connect to char device %s\n", chr->label);
+        error_report("Unable to connect to char device %s: %s\n",
+                     chr->label, error_get_pretty(err));
         qemu_chr_socket_restart_timer(chr);
     }
 

util/qemu-sockets.c

@@ -234,6 +234,7 @@ static void wait_for_connect(void *opaque)
     int val = 0, rc = 0;
     socklen_t valsize = sizeof(val);
     bool in_progress;
+    Error *err = NULL;
 
     qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
 
@@ -244,10 +245,12 @@ static void wait_for_connect(void *opaque)
     /* update rc to contain error */
     if (!rc && val) {
         rc = -1;
+        errno = val;
     }
 
     /* connect error */
     if (rc < 0) {
+        error_setg_errno(&err, errno, "Error connecting to socket");
         closesocket(s->fd);
         s->fd = rc;
     }
@@ -257,9 +260,14 @@ static void wait_for_connect(void *opaque)
         while (s->current_addr->ai_next != NULL && s->fd < 0) {
             s->current_addr = s->current_addr->ai_next;
             s->fd = inet_connect_addr(s->current_addr, &in_progress, s, NULL);
+            if (s->fd < 0) {
+                error_free(err);
+                err = NULL;
+                error_setg_errno(&err, errno, "Unable to start socket connect");
+            }
             /* connect in progress */
             if (in_progress) {
-                return;
+                goto out;
             }
         }
 
@@ -267,9 +275,11 @@ static void wait_for_connect(void *opaque)
     }
 
     if (s->callback) {
-        s->callback(s->fd, s->opaque);
+        s->callback(s->fd, err, s->opaque);
     }
     g_free(s);
+out:
+    error_free(err);
 }
 
 static int inet_connect_addr(struct addrinfo *addr, bool *in_progress,
@@ -401,7 +411,7 @@ int inet_connect_opts(QemuOpts *opts, Error **errp,
         return sock;
     } else {
         if (callback) {
-            callback(sock, opaque);
+            callback(sock, NULL, opaque);
         }
     }
     g_free(connect_state);
@@ -769,7 +779,7 @@ int unix_connect_opts(QemuOpts *opts, Error **errp,
     } else if (rc >= 0) {
         /* non blocking socket immediate success, call callback */
         if (callback != NULL) {
-            callback(sock, opaque);
+            callback(sock, NULL, opaque);
         }
     }
 
@@ -919,7 +929,7 @@ int socket_connect(SocketAddress *addr, Error **errp,
         fd = monitor_get_fd(cur_mon, addr->fd->str, errp);
         if (fd >= 0 && callback) {
             qemu_set_nonblock(fd);
-            callback(fd, opaque);
+            callback(fd, NULL, opaque);
         }
         break;