chardev: add socket chardev support to chardev-add (qmp)

qemu_chr_open_socket is split into two functions.  All initialization
after creating the socket file handler is split away into the new
qemu_chr_open_socket_fd function.

chr->filename doesn't get filled from QemuOpts any more.  Qemu gathers
the information using getsockname and getnameinfo instead.  This way it
will also work correctly for file handles passed via file descriptor
passing.

Finally qmp_chardev_open_socket() is the actual qmp hotplug
implementation which basically just calls socket_listen or
socket_connect and the new qemu_chr_open_socket_fd function.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

2 files changed, 138 insertions, 56 deletions

diff --git a/qapi-schema.json b/qapi-schema.json
index 320fa6baf1..5c3e3eb469 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -3049,6 +3049,27 @@
                                    'type'   : 'ChardevPortKind'} }
 
 ##
+# @ChardevSocket:
+#
+# Configuration info for socket chardevs.
+#
+# @addr: socket address to listen on (server=true)
+#        or connect to (server=false)
+# @server: #optional create server socket (default: true)
+# @wait: #optional wait for connect (not used for server
+#        sockets, default: false)
+# @nodelay: #optional set TCP_NODELAY socket option (default: false)
+# @telnet: #optional enable telnet protocol (default: false)
+#
+# Since: 1.4
+##
+{ 'type': 'ChardevSocket', 'data': { 'addr'     : 'SocketAddress',
+                                     '*server'  : 'bool',
+                                     '*wait'    : 'bool',
+                                     '*nodelay' : 'bool',
+                                     '*telnet'  : 'bool' } }
+
+##
 # @ChardevBackend:
 #
 # Configuration info for the new chardev backend.
@@ -3057,9 +3078,10 @@
 ##
 { 'type': 'ChardevDummy', 'data': { } }
 
-{ 'union': 'ChardevBackend', 'data': { 'file' : 'ChardevFile',
-                                       'port' : 'ChardevPort',
-                                       'null' : 'ChardevDummy' } }
+{ 'union': 'ChardevBackend', 'data': { 'file'   : 'ChardevFile',
+                                       'port'   : 'ChardevPort',
+                                       'socket' : 'ChardevSocket',
+                                       'null'   : 'ChardevDummy' } }
 
 ##
 # @ChardevReturn:
diff --git a/qemu-char.c b/qemu-char.c
index 7091e05ee2..36d7e29953 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -2438,10 +2438,88 @@ static void tcp_chr_close(CharDriverState *chr)
     qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
 }
 
-static CharDriverState *qemu_chr_open_socket(QemuOpts *opts)
+static CharDriverState *qemu_chr_open_socket_fd(int fd, bool do_nodelay,
+                                                bool is_listen, bool is_telnet,
+                                                bool is_waitconnect,
+                                                Error **errp)
 {
     CharDriverState *chr = NULL;
     TCPCharDriver *s = NULL;
+    char host[NI_MAXHOST], serv[NI_MAXSERV];
+    const char *left = "", *right = "";
+    struct sockaddr_storage ss;
+    socklen_t ss_len = sizeof(ss);
+
+    memset(&ss, 0, ss_len);
+    if (getsockname(fd, (struct sockaddr *) &ss, &ss_len) != 0) {
+        error_setg(errp, "getsockname: %s", strerror(errno));
+        return NULL;
+    }
+
+    chr = g_malloc0(sizeof(CharDriverState));
+    s = g_malloc0(sizeof(TCPCharDriver));
+
+    s->connected = 0;
+    s->fd = -1;
+    s->listen_fd = -1;
+    s->msgfd = -1;
+
+    chr->filename = g_malloc(256);
+    switch (ss.ss_family) {
+#ifndef _WIN32
+    case AF_UNIX:
+        s->is_unix = 1;
+        snprintf(chr->filename, 256, "unix:%s%s",
+                 ((struct sockaddr_un *)(&ss))->sun_path,
+                 is_listen ? ",server" : "");
+        break;
+#endif
+    case AF_INET6:
+        left  = "[";
+        right = "]";
+        /* fall through */
+    case AF_INET:
+        s->do_nodelay = do_nodelay;
+        getnameinfo((struct sockaddr *) &ss, ss_len, host, sizeof(host),
+                    serv, sizeof(serv), NI_NUMERICHOST | NI_NUMERICSERV);
+        snprintf(chr->filename, 256, "%s:%s:%s%s%s%s",
+                 is_telnet ? "telnet" : "tcp",
+                 left, host, right, serv,
+                 is_listen ? ",server" : "");
+        break;
+    }
+
+    chr->opaque = s;
+    chr->chr_write = tcp_chr_write;
+    chr->chr_close = tcp_chr_close;
+    chr->get_msgfd = tcp_get_msgfd;
+    chr->chr_add_client = tcp_chr_add_client;
+
+    if (is_listen) {
+        s->listen_fd = fd;
+        qemu_set_fd_handler2(s->listen_fd, NULL, tcp_chr_accept, NULL, chr);
+        if (is_telnet) {
+            s->do_telnetopt = 1;
+        }
+    } else {
+        s->connected = 1;
+        s->fd = fd;
+        socket_set_nodelay(fd);
+        tcp_chr_connect(chr);
+    }
+
+    if (is_listen && is_waitconnect) {
+        printf("QEMU waiting for connection on: %s\n",
+               chr->filename);
+        tcp_chr_accept(chr);
+        socket_set_nonblock(s->listen_fd);
+    }
+    return chr;
+}
+
+static CharDriverState *qemu_chr_open_socket(QemuOpts *opts)
+{
+    CharDriverState *chr = NULL;
     Error *local_err = NULL;
     int fd = -1;
     int is_listen;
@@ -2458,9 +2536,6 @@ static CharDriverState *qemu_chr_open_socket(QemuOpts *opts)
     if (!is_listen)
         is_waitconnect = 0;
 
-    chr = g_malloc0(sizeof(CharDriverState));
-    s = g_malloc0(sizeof(TCPCharDriver));
-
     if (is_unix) {
         if (is_listen) {
             fd = unix_listen_opts(opts, &local_err);
@@ -2481,56 +2556,14 @@ static CharDriverState *qemu_chr_open_socket(QemuOpts *opts)
     if (!is_waitconnect)
         socket_set_nonblock(fd);
 
-    s->connected = 0;
-    s->fd = -1;
-    s->listen_fd = -1;
-    s->msgfd = -1;
-    s->is_unix = is_unix;
-    s->do_nodelay = do_nodelay && !is_unix;
-
-    chr->opaque = s;
-    chr->chr_write = tcp_chr_write;
-    chr->chr_close = tcp_chr_close;
-    chr->get_msgfd = tcp_get_msgfd;
-    chr->chr_add_client = tcp_chr_add_client;
-
-    if (is_listen) {
-        s->listen_fd = fd;
-        qemu_set_fd_handler2(s->listen_fd, NULL, tcp_chr_accept, NULL, chr);
-        if (is_telnet)
-            s->do_telnetopt = 1;
-
-    } else {
-        s->connected = 1;
-        s->fd = fd;
-        socket_set_nodelay(fd);
-        tcp_chr_connect(chr);
-    }
-
-    /* for "info chardev" monitor command */
-    chr->filename = g_malloc(256);
-    if (is_unix) {
-        snprintf(chr->filename, 256, "unix:%s%s",
-                 qemu_opt_get(opts, "path"),
-                 qemu_opt_get_bool(opts, "server", 0) ? ",server" : "");
-    } else if (is_telnet) {
-        snprintf(chr->filename, 256, "telnet:%s:%s%s",
-                 qemu_opt_get(opts, "host"), qemu_opt_get(opts, "port"),
-                 qemu_opt_get_bool(opts, "server", 0) ? ",server" : "");
-    } else {
-        snprintf(chr->filename, 256, "tcp:%s:%s%s",
-                 qemu_opt_get(opts, "host"), qemu_opt_get(opts, "port"),
-                 qemu_opt_get_bool(opts, "server", 0) ? ",server" : "");
-    }
-
-    if (is_listen && is_waitconnect) {
-        printf("QEMU waiting for connection on: %s\n",
-               chr->filename);
-        tcp_chr_accept(chr);
-        socket_set_nonblock(s->listen_fd);
+    chr = qemu_chr_open_socket_fd(fd, do_nodelay, is_listen, is_telnet,
+                                  is_waitconnect, &local_err);
+    if (error_is_set(&local_err)) {
+        goto fail;
     }
     return chr;
 
+
  fail:
     if (local_err) {
         qerror_report_err(local_err);
@@ -2539,8 +2572,10 @@ static CharDriverState *qemu_chr_open_socket(QemuOpts *opts)
     if (fd >= 0) {
         closesocket(fd);
     }
-    g_free(s);
-    g_free(chr);
+    if (chr) {
+        g_free(chr->opaque);
+        g_free(chr);
+    }
     return NULL;
 }
 
@@ -3124,6 +3159,28 @@ static CharDriverState *qmp_chardev_open_port(ChardevPort *port, Error **errp)
 
 #endif /* WIN32 */
 
+static CharDriverState *qmp_chardev_open_socket(ChardevSocket *sock,
+                                                Error **errp)
+{
+    SocketAddress *addr = sock->addr;
+    bool do_nodelay     = sock->has_nodelay ? sock->nodelay : false;
+    bool is_listen      = sock->has_server  ? sock->server  : true;
+    bool is_telnet      = sock->has_telnet  ? sock->telnet  : false;
+    bool is_waitconnect = sock->has_wait    ? sock->wait    : false;
+    int fd;
+
+    if (is_listen) {
+        fd = socket_listen(addr, errp);
+    } else {
+        fd = socket_connect(addr, errp, NULL, NULL);
+    }
+    if (error_is_set(errp)) {
+        return NULL;
+    }
+    return qemu_chr_open_socket_fd(fd, do_nodelay, is_listen,
+                                   is_telnet, is_waitconnect, errp);
+}
+
 ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend,
                                Error **errp)
 {
@@ -3144,6 +3201,9 @@ ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend,
     case CHARDEV_BACKEND_KIND_PORT:
         chr = qmp_chardev_open_port(backend->port, errp);
         break;
+    case CHARDEV_BACKEND_KIND_SOCKET:
+        chr = qmp_chardev_open_socket(backend->socket, errp);
+        break;
     case CHARDEV_BACKEND_KIND_NULL:
         chr = qemu_chr_open_null(NULL);
         break;