Re: [Qemu-devel] [PATCH 2/6] qemu-char: Rework qemu_chr_open_socket() for reconnect

[Paolo Bonzini <pbonzini@redhat.com>]

Il 01/10/2014 23:09, minyard@acm.org ha scritto:
> From: Corey Minyard <cminyard@mvista.com>
> 
> Move all socket configuration to qmp_chardev_open_socket().
> qemu_chr_open_socket_fd() just opens the socket.  This is getting ready
> for the reconnect code, which will call open_sock_fd() on a reconnect
> attempt.
> 
> Signed-off-by: Corey Minyard <cminyard@mvista.com>
> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  qemu-char.c | 118 ++++++++++++++++++++++++++++++++++--------------------------
>  1 file changed, 68 insertions(+), 50 deletions(-)
> 
> diff --git a/qemu-char.c b/qemu-char.c
> index f9d2a02..7928a4b 100644
> --- a/qemu-char.c
> +++ b/qemu-char.c
> @@ -2891,13 +2891,11 @@ 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;
> @@ -2905,26 +2903,14 @@ 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(CHR_MAX_FILENAME_SIZE);
>      switch (ss.ss_family) {
>  #ifndef _WIN32
>      case AF_UNIX:
> -        s->is_unix = 1;
>          snprintf(chr->filename, CHR_MAX_FILENAME_SIZE, "unix:%s%s",
>                   ((struct sockaddr_un *)(&ss))->sun_path,
>                   is_listen ? ",server" : "");
> @@ -2935,7 +2921,6 @@ 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, CHR_MAX_FILENAME_SIZE, "%s:%s%s%s:%s%s",
> @@ -2945,25 +2930,11 @@ static CharDriverState *qemu_chr_open_socket_fd(int fd, bool do_nodelay,
>          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;
> @@ -2972,15 +2943,28 @@ 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 chr;

You should return true here rather than chr.

Paolo

>  }
>  
> +static bool qemu_chr_open_socket_fd(CharDriverState *chr, SocketAddress *addr,
> +                                    bool is_listen, bool is_telnet,
> +                                    Error **errp)
> +{
> +    int fd;
> +
> +    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);
> +}
> +
>  /*********************************************************/
>  /* Ring buffer chardev */
>  
> @@ -3969,23 +3953,57 @@ static CharDriverState *qmp_chardev_open_parallel(ChardevHostdev *parallel,
>  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;
> +
> +    chr = qemu_chr_alloc();
> +    s = g_malloc0(sizeof(TCPCharDriver));
> +
> +    s->fd = -1;
> +    s->listen_fd = -1;
> +    s->is_unix = addr->kind == SOCKET_ADDRESS_KIND_UNIX;
> +    s->do_nodelay = do_nodelay;
> +
> +    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(CHR_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;
> +        }
>      }
> -    if (fd < 0) {
> +
> +    if (!qemu_chr_open_socket_fd(chr, addr, is_listen, is_telnet, errp)) {
> +        g_free(s);
> +        g_free(chr->filename);
> +        g_free(chr);
>          return NULL;
>      }
> -    return qemu_chr_open_socket_fd(fd, do_nodelay, is_listen,
> -                                   is_telnet, is_waitconnect, errp);
> +
> +    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 chr;
>  }
>  
>  static CharDriverState *qmp_chardev_open_udp(ChardevUdp *udp,
>