use inet_listen()/inet_connect() to support ipv6 migration

Use help functions in qemu-socket.c for tcp migration,
which already support ipv6 addresses.

Currently errp will be set to UNDEFINED_ERROR when migration fails,
qemu would output "migration failed: ...", and current user can
see a message("An undefined error has occurred") in monitor.

This patch changed tcp_start_outgoing_migration()/inet_connect()
/inet_connect_opts(), socket error would be passed back,
then current user can see a meaningful err message in monitor.

Qemu will exit if listening fails, so output socket error
to qemu stderr.

For IPv6 brackets must be mandatory if you require a port.
Referencing to RFC5952, the recommended format is:
  [2312::8274]:5200

test status: Successed
listen side: qemu-kvm .... -incoming tcp:[2312::8274]:5200
client side: qemu-kvm ...
             (qemu) migrate -d tcp:[2312::8274]:5200

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>

1 files changed, 4 insertions, 3 deletions

diff --git a/migration.h b/migration.h
index 691b367..2e9ca2e 100644
--- a/migration.h
+++ b/migration.h
@@ -37,7 +37,7 @@ struct MigrationState
 
 void process_incoming_migration(QEMUFile *f);
 
-int qemu_start_incoming_migration(const char *uri);
+int qemu_start_incoming_migration(const char *uri, Error **errp);
 
 uint64_t migrate_max_downtime(void);
 
@@ -49,9 +49,10 @@ int exec_start_incoming_migration(const char *host_port);
 
 int exec_start_outgoing_migration(MigrationState *s, const char *host_port);
 
-int tcp_start_incoming_migration(const char *host_port);
+int tcp_start_incoming_migration(const char *host_port, Error **errp);
 
-int tcp_start_outgoing_migration(MigrationState *s, const char *host_port);
+int tcp_start_outgoing_migration(MigrationState *s, const char *host_port,
+                                 Error **errp);
 
 int unix_start_incoming_migration(const char *path);