From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58919) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XV6Dl-0007lJ-QF for qemu-devel@nongnu.org; Fri, 19 Sep 2014 18:00:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XV6Df-00026O-Dm for qemu-devel@nongnu.org; Fri, 19 Sep 2014 18:00:05 -0400 Received: from mail-oi0-x235.google.com ([2607:f8b0:4003:c06::235]:47912) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XV6Df-00024X-6w for qemu-devel@nongnu.org; Fri, 19 Sep 2014 17:59:59 -0400 Received: by mail-oi0-f53.google.com with SMTP id i138so2055530oig.26 for ; Fri, 19 Sep 2014 14:59:53 -0700 (PDT) Sender: Corey Minyard From: minyard@acm.org Date: Fri, 19 Sep 2014 16:58:57 -0500 Message-Id: <1411163937-19891-1-git-send-email-minyard@acm.org> Subject: [Qemu-devel] [PATCH] chardev: Add reconnecting to client sockets List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: mjg59@srcf.ucam.org, Corey Minyard , hwd@huawei.com, bcketchum@gmail.com, mst@redhat.com, afaerber@suse.de From: Corey Minyard Adds a "recon" option to socket backends that gives a reconnect timeout. This only applies to client sockets. If the other end of a socket closes the connection, qemu will attempt to reconnect after the given number of seconds. This rearranges things a bit, all socket configuration is moved to qmp_chardev_open_socket() and that only gets called once at startup. qemu_chr_open_socket_fd() is called to open or re-open the connection. Signed-off-by: Corey Minyard --- qapi-schema.json | 6 +- qemu-char.c | 209 +++++++++++++++++++++++++++++++++++++++++-------------- qemu-options.hx | 20 ++++-- 3 files changed, 174 insertions(+), 61 deletions(-) diff --git a/qapi-schema.json b/qapi-schema.json index 689b548..f42562f 100644 --- a/qapi-schema.json +++ b/qapi-schema.json @@ -2648,6 +2648,9 @@ # @nodelay: #optional set TCP_NODELAY socket option (default: false) # @telnet: #optional enable telnet protocol on server # sockets (default: false) +# @recon: #optional If not a server socket, if the socket disconnect +# then reconnect after the given number of seconds. Setting +# to zero disables this function. (default: 0) # # Since: 1.4 ## @@ -2655,7 +2658,8 @@ '*server' : 'bool', '*wait' : 'bool', '*nodelay' : 'bool', - '*telnet' : 'bool' } } + '*telnet' : 'bool', + '*recon' : 'int' } } ## # @ChardevUdp: diff --git a/qemu-char.c b/qemu-char.c index 2a3cb9f..4c6b5e2 100644 --- a/qemu-char.c +++ b/qemu-char.c @@ -2402,8 +2402,22 @@ typedef struct { int read_msgfds_num; int *write_msgfds; int write_msgfds_num; + + QEMUTimer *recon_timer; + int64_t recon_time; + + /* Only set if reconnect is enabled */ + SocketAddress *addr; } TCPCharDriver; +#define SOCKET_MAX_FILENAME_SIZE 256 + +static void qemu_chr_socket_restart_timer(TCPCharDriver *s) +{ + timer_mod(s->recon_timer, + (get_clock() + (s->recon_time * get_ticks_per_sec()))); +} + static gboolean tcp_chr_accept(GIOChannel *chan, GIOCondition cond, void *opaque); #ifndef _WIN32 @@ -2683,6 +2697,9 @@ static void tcp_chr_disconnect(CharDriverState *chr) closesocket(s->fd); s->fd = -1; qemu_chr_be_event(chr, CHR_EVENT_CLOSED); + if (s->recon_timer) { + qemu_chr_socket_restart_timer(s); + } } static gboolean tcp_chr_read(GIOChannel *chan, GIOCondition cond, void *opaque) @@ -2881,13 +2898,11 @@ static void tcp_chr_close(CharDriverState *chr) qemu_chr_be_event(chr, CHR_EVENT_CLOSED); } -static CharDriverState *qemu_chr_open_socket_fd(int fd, bool do_nodelay, - bool is_listen, bool is_telnet, - bool is_waitconnect, - Error **errp) +static bool qemu_chr_finish_socket_connection(CharDriverState *chr, int fd, + bool is_listen, bool is_telnet, + Error **errp) { - CharDriverState *chr = NULL; - TCPCharDriver *s = NULL; + TCPCharDriver *s = chr->opaque; char host[NI_MAXHOST], serv[NI_MAXSERV]; const char *left = "", *right = ""; struct sockaddr_storage ss; @@ -2895,27 +2910,15 @@ static CharDriverState *qemu_chr_open_socket_fd(int fd, bool do_nodelay, memset(&ss, 0, ss_len); if (getsockname(fd, (struct sockaddr *) &ss, &ss_len) != 0) { + closesocket(fd); error_setg_errno(errp, errno, "getsockname"); - return NULL; + return false; } - chr = qemu_chr_alloc(); - s = g_malloc0(sizeof(TCPCharDriver)); - - s->connected = 0; - s->fd = -1; - s->listen_fd = -1; - s->read_msgfds = 0; - s->read_msgfds_num = 0; - s->write_msgfds = 0; - s->write_msgfds_num = 0; - - 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", + snprintf(chr->filename, SOCKET_MAX_FILENAME_SIZE, "unix:%s%s", ((struct sockaddr_un *)(&ss))->sun_path, is_listen ? ",server" : ""); break; @@ -2925,35 +2928,20 @@ static CharDriverState *qemu_chr_open_socket_fd(int fd, bool do_nodelay, 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", + snprintf(chr->filename, SOCKET_MAX_FILENAME_SIZE, "%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_sync_read = tcp_chr_sync_read; - chr->chr_close = tcp_chr_close; - chr->get_msgfds = tcp_get_msgfds; - chr->set_msgfds = tcp_set_msgfds; - chr->chr_add_client = tcp_chr_add_client; - chr->chr_add_watch = tcp_chr_add_watch; - chr->chr_update_read_handler = tcp_chr_update_read_handler; - /* be isn't opened until we get a connection */ - chr->explicit_be_open = true; - if (is_listen) { s->listen_fd = fd; s->listen_chan = io_channel_from_socket(s->listen_fd); - s->listen_tag = g_io_add_watch(s->listen_chan, G_IO_IN, tcp_chr_accept, chr); - if (is_telnet) { - s->do_telnetopt = 1; - } + s->listen_tag = g_io_add_watch(s->listen_chan, G_IO_IN, tcp_chr_accept, + chr); } else { s->connected = 1; s->fd = fd; @@ -2962,13 +2950,54 @@ static CharDriverState *qemu_chr_open_socket_fd(int fd, bool do_nodelay, tcp_chr_connect(chr); } - if (is_listen && is_waitconnect) { - fprintf(stderr, "QEMU waiting for connection on: %s\n", - chr->filename); - tcp_chr_accept(s->listen_chan, G_IO_IN, chr); - qemu_set_nonblock(s->listen_fd); + return true; +} + +static void qemu_chr_socket_connected(int fd, void *opaque) +{ + CharDriverState *chr = opaque; + TCPCharDriver *s = chr->opaque; + Error *err = NULL; + + if (fd >= 0) { + if (qemu_chr_finish_socket_connection(chr, fd, false, false, &err)) { + return; + } + if (err) { + error_report("%s", error_get_pretty(err)); + error_free(err); + } + closesocket(fd); } - return chr; + + s->connected = 0; + qemu_chr_socket_restart_timer(s); +} + +static bool qemu_chr_open_socket_fd(CharDriverState *chr, SocketAddress *addr, + bool do_nodelay, + bool is_listen, bool is_telnet, + Error **errp) +{ + TCPCharDriver *s = chr->opaque; + int fd; + + if (s->recon_timer) { + fd = socket_connect(addr, errp, qemu_chr_socket_connected, chr); + return (fd >= 0); + } + + if (is_listen) { + fd = socket_listen(addr, errp); + } else { + fd = socket_connect(addr, errp, NULL, NULL); + } + if (fd < 0) { + return false; + } + + return qemu_chr_finish_socket_connection(chr, fd, is_listen, is_telnet, + errp); } /*********************************************************/ @@ -3388,6 +3417,7 @@ static void qemu_chr_parse_socket(QemuOpts *opts, ChardevBackend *backend, bool is_waitconnect = is_listen && qemu_opt_get_bool(opts, "wait", true); bool is_telnet = qemu_opt_get_bool(opts, "telnet", false); bool do_nodelay = !qemu_opt_get_bool(opts, "delay", true); + int64_t recon = qemu_opt_get_number(opts, "recon", 0); const char *path = qemu_opt_get(opts, "path"); const char *host = qemu_opt_get(opts, "host"); const char *port = qemu_opt_get(opts, "port"); @@ -3414,6 +3444,8 @@ static void qemu_chr_parse_socket(QemuOpts *opts, ChardevBackend *backend, backend->socket->telnet = is_telnet; backend->socket->has_wait = true; backend->socket->wait = is_waitconnect; + backend->socket->has_recon = true; + backend->socket->recon = recon; addr = g_new0(SocketAddress, 1); if (path) { @@ -3813,6 +3845,9 @@ QemuOptsList qemu_chardev_opts = { .name = "delay", .type = QEMU_OPT_BOOL, },{ + .name = "recon", + .type = QEMU_OPT_NUMBER, + },{ .name = "telnet", .type = QEMU_OPT_BOOL, },{ @@ -3956,26 +3991,94 @@ static CharDriverState *qmp_chardev_open_parallel(ChardevHostdev *parallel, #endif /* WIN32 */ +static void socket_recon_timeout(void *opaque) +{ + CharDriverState *chr = opaque; + TCPCharDriver *s = chr->opaque; + Error *err; + + if (chr->be_open) { + return; + } + + if (!qemu_chr_open_socket_fd(chr, s->addr, s->do_nodelay, false, false, + &err)) { + error_report("Unable to connect to char device %s\n", chr->label); + qemu_chr_socket_restart_timer(s); + } +} + static CharDriverState *qmp_chardev_open_socket(ChardevSocket *sock, Error **errp) { + CharDriverState *chr; + TCPCharDriver *s; 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; + int64_t recon = sock->has_recon ? sock->recon : 0; + + chr = qemu_chr_alloc(); + s = g_malloc0(sizeof(TCPCharDriver)); + + s->connected = 0; + s->fd = -1; + s->listen_fd = -1; + s->read_msgfds = 0; + s->read_msgfds_num = 0; + s->write_msgfds = 0; + s->write_msgfds_num = 0; + s->is_unix = addr->kind == SOCKET_ADDRESS_KIND_UNIX; + + chr->opaque = s; + chr->chr_write = tcp_chr_write; + chr->chr_sync_read = tcp_chr_sync_read; + chr->chr_close = tcp_chr_close; + chr->get_msgfds = tcp_get_msgfds; + chr->set_msgfds = tcp_set_msgfds; + chr->chr_add_client = tcp_chr_add_client; + chr->chr_add_watch = tcp_chr_add_watch; + chr->chr_update_read_handler = tcp_chr_update_read_handler; + /* be isn't opened until we get a connection */ + chr->explicit_be_open = true; + + chr->filename = g_malloc(SOCKET_MAX_FILENAME_SIZE); if (is_listen) { - fd = socket_listen(addr, errp); - } else { - fd = socket_connect(addr, errp, NULL, NULL); + if (is_telnet) { + s->do_telnetopt = 1; + } + } else if (recon > 0) { + s->recon_timer = timer_new(QEMU_CLOCK_REALTIME, SCALE_NS, + socket_recon_timeout, chr); + s->recon_time = recon; + s->do_nodelay = do_nodelay; + s->addr = addr; /* Steal the address from the socket */ + sock->addr = NULL; + } + + if (!qemu_chr_open_socket_fd(chr, addr, do_nodelay, is_listen, + is_telnet, errp)) { + if (s->recon_timer) { + qemu_chr_socket_restart_timer(s); + } else { + g_free(s); + g_free(chr->filename); + g_free(chr); + return NULL; + } } - if (fd < 0) { - return NULL; + + if (is_listen && is_waitconnect) { + fprintf(stderr, "QEMU waiting for connection on: %s\n", + chr->filename); + tcp_chr_accept(s->listen_chan, G_IO_IN, chr); + qemu_set_nonblock(s->listen_fd); } - return qemu_chr_open_socket_fd(fd, do_nodelay, is_listen, - is_telnet, is_waitconnect, errp); + + return chr; } static CharDriverState *qmp_chardev_open_udp(ChardevUdp *udp, diff --git a/qemu-options.hx b/qemu-options.hx index 365b56c..619eacd 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -1930,9 +1930,9 @@ ETEXI DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, "-chardev null,id=id[,mux=on|off]\n" - "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay]\n" - " [,server][,nowait][,telnet][,mux=on|off] (tcp)\n" - "-chardev socket,id=id,path=path[,server][,nowait][,telnet],[mux=on|off] (unix)\n" + "-chardev socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,recon=recon_time]\n" + " [,server][,nowait][,telnet][,recon=recon_time][,mux=on|off] (tcp)\n" + "-chardev socket,id=id,path=path[,server][,nowait][,telnet][,recon=recon_time][,mux=on|off] (unix)\n" "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n" " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n" "-chardev msmouse,id=id[,mux=on|off]\n" @@ -2004,7 +2004,7 @@ Options to each backend are described below. A void device. This device will not emit any data, and will drop any data it receives. The null backend does not take any options. -@item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet] +@item -chardev socket ,id=@var{id} [@var{TCP options} or @var{unix options}] [,server] [,nowait] [,telnet] [,recon=recon_time] Create a two-way stream socket, which can be either a TCP or a unix socket. A unix socket will be created if @option{path} is specified. Behaviour is @@ -2018,6 +2018,10 @@ connect to a listening socket. @option{telnet} specifies that traffic on the socket should interpret telnet escape sequences. +@option{recon} sets the timeout for reconnecting on non-server sockets when +the remote end goes away. qemu will delay this many seconds and then attempt +to reconnect. Zero disables reconnecting, and is the default. + TCP and unix socket options are given below: @table @option @@ -2687,14 +2691,16 @@ telnet on port 5555 to access the QEMU port. localhost 5555 @end table -@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay] +@item tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,recon=recon_time] The TCP Net Console has two modes of operation. It can send the serial I/O to a location or wait for a connection from a location. By default the TCP Net Console is sent to @var{host} at the @var{port}. If you use the @var{server} option QEMU will wait for a client socket application to connect to the port before continuing, unless the @code{nowait} option was specified. The @code{nodelay} option disables the Nagle buffering -algorithm. If @var{host} is omitted, 0.0.0.0 is assumed. Only +algorithm. The @code{recon} option only applies if @var{noserver} is +set, if the connection goes down it will attempt to reconnect at the +given interval. If @var{host} is omitted, 0.0.0.0 is assumed. Only one TCP connection at a time is accepted. You can use @code{telnet} to connect to the corresponding character device. @table @code @@ -2715,7 +2721,7 @@ MAGIC_SYSRQ sequence if you use a telnet that supports sending the break sequence. Typically in unix telnet you do it with Control-] and then type "send break" followed by pressing the enter key. -@item unix:@var{path}[,server][,nowait] +@item unix:@var{path}[,server][,nowait][,recon=recon_time] A unix domain socket is used instead of a tcp socket. The option works the same as if you had specified @code{-serial tcp} except the unix domain socket @var{path} is used for connections. -- 1.8.3.1