sockets: use error class to pass listen error

Add a new argument in inet_listen()/inet_listen_opts()
to pass back listen error.

Change nbd, qemu-char, vnc to use new interface.

Signed-off-by: Amos Kong <akong@redhat.com>
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/qemu-sockets.c b/qemu-sockets.c
index ce3f06c..46c7619 100644
--- a/qemu-sockets.c
+++ b/qemu-sockets.c
@@ -103,7 +103,7 @@
     return "unknown";
 }
 
-int inet_listen_opts(QemuOpts *opts, int port_offset)
+int inet_listen_opts(QemuOpts *opts, int port_offset, Error **errp)
 {
     struct addrinfo ai,*res,*e;
     const char *addr;
@@ -120,6 +120,7 @@
     if ((qemu_opt_get(opts, "host") == NULL) ||
         (qemu_opt_get(opts, "port") == NULL)) {
         fprintf(stderr, "%s: host and/or port not specified\n", __FUNCTION__);
+        error_set(errp, QERR_SOCKET_CREATE_FAILED);
         return -1;
     }
     pstrcpy(port, sizeof(port), qemu_opt_get(opts, "port"));
@@ -138,6 +139,7 @@
     if (rc != 0) {
         fprintf(stderr,"getaddrinfo(%s,%s): %s\n", addr, port,
                 gai_strerror(rc));
+        error_set(errp, QERR_SOCKET_CREATE_FAILED);
         return -1;
     }
 
@@ -150,6 +152,9 @@
         if (slisten < 0) {
             fprintf(stderr,"%s: socket(%s): %s\n", __FUNCTION__,
                     inet_strfamily(e->ai_family), strerror(errno));
+            if (!e->ai_next) {
+                error_set(errp, QERR_SOCKET_CREATE_FAILED);
+            }
             continue;
         }
 
@@ -173,6 +178,9 @@
                 fprintf(stderr,"%s: bind(%s,%s,%d): %s\n", __FUNCTION__,
                         inet_strfamily(e->ai_family), uaddr, inet_getport(e),
                         strerror(errno));
+                if (!e->ai_next) {
+                    error_set(errp, QERR_SOCKET_BIND_FAILED);
+                }
             }
         }
         closesocket(slisten);
@@ -183,6 +191,7 @@
 
 listen:
     if (listen(slisten,1) != 0) {
+        error_set(errp, QERR_SOCKET_LISTEN_FAILED);
         perror("listen");
         closesocket(slisten);
         freeaddrinfo(res);
@@ -446,7 +455,7 @@
 }
 
 int inet_listen(const char *str, char *ostr, int olen,
-                int socktype, int port_offset)
+                int socktype, int port_offset, Error **errp)
 {
     QemuOpts *opts;
     char *optstr;
@@ -454,7 +463,7 @@
 
     opts = qemu_opts_create(&dummy_opts, NULL, 0);
     if (inet_parse(opts, str) == 0) {
-        sock = inet_listen_opts(opts, port_offset);
+        sock = inet_listen_opts(opts, port_offset, errp);
         if (sock != -1 && ostr) {
             optstr = strchr(str, ',');
             if (qemu_opt_get_bool(opts, "ipv6", 0)) {
@@ -469,6 +478,8 @@
                          optstr ? optstr : "");
             }
         }
+    } else {
+        error_set(errp, QERR_SOCKET_CREATE_FAILED);
     }
     qemu_opts_del(opts);
     return sock;