Hi
On Tue, Dec 18, 2018 at 2:01 PM <elohi...@gmail.com> wrote:
>
> From: Xie Yongji <xieyon...@baidu.com>
>
> New option "disconnected" is added to init the chardev socket
> in disconnected state. Then we can use qemu_chr_fe_wait_connected()
> to connect when necessary. Now it would be used for unix domain
> socket of vhost-user-blk device to support reconnect.
What difference does that make if you wait for connection in
qemu_chr_fe_wait_connected(), or during chardev setup?
"disconnected" is misleading, would it be possible to reuse
"wait/nowait" instead?
Tests would be welcome.
>
> Suggested-by: Yury Kotov <yury-ko...@yandex-team.ru>
> Signed-off-by: Xie Yongji <xieyon...@baidu.com>
> Signed-off-by: Zhang Yu <zhangy...@baidu.com>
> ---
> chardev/char-socket.c | 10 ++++++++++
> chardev/char.c | 3 +++
> qapi/char.json | 3 +++
> qemu-options.hx | 28 ++++++++++++++++------------
> 4 files changed, 32 insertions(+), 12 deletions(-)
>
> diff --git a/chardev/char-socket.c b/chardev/char-socket.c
> index eaa8e8b68f..2464d7abad 100644
> --- a/chardev/char-socket.c
> +++ b/chardev/char-socket.c
> @@ -70,6 +70,7 @@ typedef struct {
> TCPChardevTelnetInit *telnet_init;
>
> bool is_websock;
> + bool is_disconnected;
>
> GSource *reconnect_timer;
> int64_t reconnect_time;
> @@ -1000,6 +1001,7 @@ static void qmp_chardev_open_socket(Chardev *chr,
> bool is_tn3270 = sock->has_tn3270 ? sock->tn3270 : false;
> bool is_waitconnect = sock->has_wait ? sock->wait : false;
> bool is_websock = sock->has_websocket ? sock->websocket : false;
> + bool is_disconnected = sock->has_disconnected ? sock->disconnected :
> false;
> int64_t reconnect = sock->has_reconnect ? sock->reconnect : 0;
> QIOChannelSocket *sioc = NULL;
> SocketAddress *addr;
> @@ -1072,6 +1074,10 @@ static void qmp_chardev_open_socket(Chardev *chr,
> s->reconnect_time = reconnect;
> }
>
> + if (!s->is_listen && is_disconnected) {
> + return;
> + }
> +
> if (s->reconnect_time) {
> tcp_chr_connect_async(chr);
> } else {
> @@ -1125,6 +1131,8 @@ static void qemu_chr_parse_socket(QemuOpts *opts,
> ChardevBackend *backend,
> bool is_tn3270 = qemu_opt_get_bool(opts, "tn3270", false);
> bool is_websock = qemu_opt_get_bool(opts, "websocket", false);
> bool do_nodelay = !qemu_opt_get_bool(opts, "delay", true);
> + bool is_disconnected = !is_listen &&
> + qemu_opt_get_bool(opts, "disconnected", false);
> int64_t reconnect = qemu_opt_get_number(opts, "reconnect", 0);
> const char *path = qemu_opt_get(opts, "path");
> const char *host = qemu_opt_get(opts, "host");
> @@ -1176,6 +1184,8 @@ static void qemu_chr_parse_socket(QemuOpts *opts,
> ChardevBackend *backend,
> sock->websocket = is_websock;
> sock->has_wait = true;
> sock->wait = is_waitconnect;
> + sock->has_disconnected = true;
> + sock->disconnected = is_disconnected;
> sock->has_reconnect = qemu_opt_find(opts, "reconnect");
> sock->reconnect = reconnect;
> sock->tls_creds = g_strdup(tls_creds);
> diff --git a/chardev/char.c b/chardev/char.c
> index ccba36bafb..fb916eb176 100644
> --- a/chardev/char.c
> +++ b/chardev/char.c
> @@ -862,6 +862,9 @@ QemuOptsList qemu_chardev_opts = {
> },{
> .name = "delay",
> .type = QEMU_OPT_BOOL,
> + },{
> + .name = "disconnected",
> + .type = QEMU_OPT_BOOL,
> },{
> .name = "reconnect",
> .type = QEMU_OPT_NUMBER,
> diff --git a/qapi/char.json b/qapi/char.json
> index 77ed847972..b634442229 100644
> --- a/qapi/char.json
> +++ b/qapi/char.json
> @@ -258,6 +258,8 @@
> # sockets (default: false) (Since: 2.10)
> # @websocket: enable websocket protocol on server
> # sockets (default: false) (Since: 3.1)
> +# @disconnected: init a client socket in disconnected
> +# state (default: false) (Since: 4.0)
> # @reconnect: For a client socket, if a socket is disconnected,
> # then attempt a reconnect after the given number of seconds.
> # Setting this to zero disables this function. (default: 0)
> @@ -274,6 +276,7 @@
> '*telnet': 'bool',
> '*tn3270': 'bool',
> '*websocket': 'bool',
> + '*disconnected': 'bool',
> '*reconnect': 'int' },
> 'base': 'ChardevCommon' }
>
> diff --git a/qemu-options.hx b/qemu-options.hx
> index df42116ecc..f9d3495dc8 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -2418,10 +2418,10 @@ DEF("chardev", HAS_ARG, QEMU_OPTION_chardev,
> "-chardev help\n"
> "-chardev null,id=id[,mux=on|off][,logfile=PATH][,logappend=on|off]\n"
> "-chardev
> socket,id=id[,host=host],port=port[,to=to][,ipv4][,ipv6][,nodelay][,reconnect=seconds]\n"
> - "
> [,server][,nowait][,telnet][,websocket][,reconnect=seconds][,mux=on|off]\n"
> - " [,logfile=PATH][,logappend=on|off][,tls-creds=ID] (tcp)\n"
> - "-chardev
> socket,id=id,path=path[,server][,nowait][,telnet][,websocket][,reconnect=seconds]\n"
> - " [,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n"
> + "
> [,server][,nowait][,telnet][,websocket][,disconnected][,reconnect=seconds]\n"
> + " [,mux=on|off][,logfile=PATH][,logappend=on|off][,tls-creds=ID]
> (tcp)\n"
> + "-chardev
> socket,id=id,path=path[,server][,nowait][,telnet][,websocket][,disconnected]\n"
> + "
> [,reconnect=seconds][,mux=on|off][,logfile=PATH][,logappend=on|off] (unix)\n"
> "-chardev udp,id=id[,host=host],port=port[,localaddr=localaddr]\n"
> " [,localport=localport][,ipv4][,ipv6][,mux=on|off]\n"
> " [,logfile=PATH][,logappend=on|off]\n"
> @@ -2548,7 +2548,7 @@ The available backends are:
> 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][,websocket][,reconnect=@var{seconds}][,tls-creds=@var{id}]
> +@item -chardev socket,id=@var{id}[,@var{TCP options} or @var{unix
> options}][,server][,nowait][,telnet][,websocket][,disconnected][,reconnect=@var{seconds}][,tls-creds=@var{id}]
>
> 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
> @@ -2565,6 +2565,9 @@ escape sequences.
> @option{websocket} specifies that the socket uses WebSocket protocol for
> communication.
>
> +@option{disconnected} specifies that the non-server socket should not try
> +to connect the remote during initialization.
> +
> @option{reconnect} 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.
> @@ -3087,18 +3090,19 @@ telnet on port 5555 to access the QEMU port.
> localhost 5555
> @end table
>
> -@item
> tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,reconnect=@var{seconds}]
> +@item
> tcp:[@var{host}]:@var{port}[,@var{server}][,nowait][,nodelay][,disconnected]
> +[,reconnect=@var{seconds}]
> 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. The @code{reconnect} 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.
> +algorithm. If @var{noserver} is specified, the @code{disconnected} will
> disallow
> +QEMU to connect during initialization, and the @code{reconnect} will ask QEMU
> +to reconnect at the given interval when the connection goes down. 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
> @item Example to send tcp console to 192.168.0.2 port 4444
> -serial tcp:192.168.0.2:4444
> @@ -3121,7 +3125,7 @@ type "send break" followed by pressing the enter key.
> The WebSocket protocol is used instead of raw tcp socket. The port acts as
> a WebSocket server. Client mode is not supported.
>
> -@item unix:@var{path}[,server][,nowait][,reconnect=@var{seconds}]
> +@item
> unix:@var{path}[,server][,nowait][,disconnected][,reconnect=@var{seconds}]
> 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.
> --
> 2.17.1
>
