Re: [PATCH v5 07/12] net: stream: add unix socket

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Laurent Vivier (lvivier@redhat.com) wrote:
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
> Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
> ---
>  net/stream.c    | 106 +++++++++++++++++++++++++++++++++++++++++++++---
>  qemu-options.hx |   1 +
>  2 files changed, 102 insertions(+), 5 deletions(-)
> 
> diff --git a/net/stream.c b/net/stream.c
> index e8afbaca50b6..1a2bc237707e 100644
> --- a/net/stream.c
> +++ b/net/stream.c
> @@ -235,7 +235,7 @@ static NetStreamState *net_stream_fd_init_stream(NetClientState *peer,
>  static void net_stream_accept(void *opaque)
>  {
>      NetStreamState *s = opaque;
> -    struct sockaddr_in saddr;
> +    struct sockaddr_storage saddr;
>      socklen_t len;
>      int fd;
>  
> @@ -253,9 +253,27 @@ static void net_stream_accept(void *opaque)
>      s->fd = fd;
>      s->nc.link_down = false;
>      net_stream_connect(s);
> -    snprintf(s->nc.info_str, sizeof(s->nc.info_str),
> -             "connection from %s:%d",
> -             inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
> +    switch (saddr.ss_family) {
> +    case AF_INET: {
> +        struct sockaddr_in *saddr_in = (struct sockaddr_in *)&saddr;
> +
> +        snprintf(s->nc.info_str, sizeof(s->nc.info_str),
> +                 "connection from %s:%d",
> +                 inet_ntoa(saddr_in->sin_addr), ntohs(saddr_in->sin_port));
> +        break;
> +    }
> +    case AF_UNIX: {
> +        struct sockaddr_un saddr_un;
> +
> +        len = sizeof(saddr_un);
> +        getsockname(s->listen_fd, (struct sockaddr *)&saddr_un, &len);
> +        snprintf(s->nc.info_str, sizeof(s->nc.info_str),
> +                 "connect from %s", saddr_un.sun_path);
> +        break;
> +    }
> +    default:
> +        g_assert_not_reached();
> +    }
>  }
>  
>  static int net_stream_server_init(NetClientState *peer,
> @@ -295,6 +313,42 @@ static int net_stream_server_init(NetClientState *peer,
>          }
>          break;
>      }
> +    case SOCKET_ADDRESS_TYPE_UNIX: {
> +        struct sockaddr_un saddr_un;
> +
> +        ret = unlink(addr->u.q_unix.path);
> +        if (ret < 0 && errno != ENOENT) {
> +            error_setg_errno(errp, errno, "failed to unlink socket %s",
> +                             addr->u.q_unix.path);
> +            return -1;
> +        }
> +
> +        saddr_un.sun_family = PF_UNIX;
> +        ret = snprintf(saddr_un.sun_path, sizeof(saddr_un.sun_path), "%s",
> +                       addr->u.q_unix.path);
> +        if (ret < 0 || ret >= sizeof(saddr_un.sun_path)) {
> +            error_setg(errp, "UNIX socket path '%s' is too long",
> +                       addr->u.q_unix.path);
> +            error_append_hint(errp, "Path must be less than %zu bytes\n",
> +                              sizeof(saddr_un.sun_path));

return here?
> +
> +        fd = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
> +        if (fd < 0) {
> +            error_setg_errno(errp, errno, "can't create stream socket");
> +            return -1;
> +        }
> +        qemu_socket_set_nonblock(fd);
> +
> +        ret = bind(fd, (struct sockaddr *)&saddr_un, sizeof(saddr_un));
> +        if (ret < 0) {
> +            error_setg_errno(errp, errno, "can't create socket with path: %s",
> +                             saddr_un.sun_path);
> +            closesocket(fd);
> +            return -1;
> +        }
> +        break;
> +    }
>      case SOCKET_ADDRESS_TYPE_FD:
>          fd = monitor_fd_param(monitor_cur(), addr->u.fd.str, errp);
>          if (fd == -1) {
> @@ -380,6 +434,48 @@ static int net_stream_client_init(NetClientState *peer,
>                                     ntohs(saddr_in.sin_port));
>          break;
>      }
> +    case SOCKET_ADDRESS_TYPE_UNIX: {
> +        struct sockaddr_un saddr_un;
> +
> +        saddr_un.sun_family = PF_UNIX;
> +        ret = snprintf(saddr_un.sun_path, sizeof(saddr_un.sun_path), "%s",
> +                       addr->u.q_unix.path);
> +        if (ret < 0 || ret >= sizeof(saddr_un.sun_path)) {
> +            error_setg(errp, "UNIX socket path '%s' is too long",
> +                       addr->u.q_unix.path);
> +            error_append_hint(errp, "Path must be less than %zu bytes\n",
> +                              sizeof(saddr_un.sun_path));

and here

(Can you not do a lot of this just by calling util/qemu-sockets.c
unix_connect?)

> +        }
> +
> +        fd = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
> +        if (fd < 0) {
> +            error_setg_errno(errp, errno, "can't create stream socket");
> +            return -1;
> +        }
> +        qemu_socket_set_nonblock(fd);
> +
> +        connected = 0;
> +        for (;;) {
> +            ret = connect(fd, (struct sockaddr *)&saddr_un, sizeof(saddr_un));
> +            if (ret < 0) {
> +                if (errno == EINTR || errno == EWOULDBLOCK) {
> +                    /* continue */
> +                } else if (errno == EAGAIN ||
> +                           errno == EALREADY) {
> +                    break;
> +                } else {
> +                    error_setg_errno(errp, errno, "can't connect socket");
> +                    closesocket(fd);
> +                    return -1;
> +                }
> +            } else {
> +                connected = 1;
> +                break;
> +            }
> +        }
> +        info_str = g_strdup_printf(" connect to %s", saddr_un.sun_path);
> +        break;
> +    }
>      case SOCKET_ADDRESS_TYPE_FD:
>          fd = monitor_fd_param(monitor_cur(), addr->u.fd.str, errp);
>          if (fd == -1) {
> @@ -395,7 +491,7 @@ static int net_stream_client_init(NetClientState *peer,
>          info_str = g_strdup_printf("connect to fd %d", fd);
>          break;
>      default:
> -        error_setg(errp, "only support inet or fd type");
> +        error_setg(errp, "only support inet, unix or fd type");
>          return -1;
>      }
>  
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 2be0cbd2549b..23ff12c1b183 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -2723,6 +2723,7 @@ DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
>      "                configure a network backend to connect to another network\n"
>      "                using an UDP tunnel\n"
>      "-netdev stream,id=str[,server=on|off],addr.type=inet,addr.host=host,addr.port=port\n"
> +    "-netdev stream,id=str[,server=on|off],addr.type=unix,addr.path=path\n"
>      "-netdev stream,id=str[,server=on|off],addr.type=fd,addr.str=h\n"
>      "                configure a network backend to connect to another network\n"
>      "                using a socket connection in stream mode.\n"
> -- 
> 2.36.1
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK