Re: [Qemu-devel] [PATCH 01/12] chardev: fix validation of options for QMP created chardevs

["Marc-André Lureau" <marcandre.lureau@redhat.com>]

Hi

On Tue, Jan 15, 2019 at 6:53 PM Daniel P. Berrangé <berrange@redhat.com> wrote:
>
> The TLS creds option is not valid with certain address types. The user
> config was only checked for errors when parsing legacy QemuOpts, thus
> the user could pass unsupported values via QMP.
>
> Pull all code for validating options out into a new method
> qmp_chardev_validate_socket, that is called from the main
> qmp_chardev_open_socket method. This adds a missing check for rejecting
> TLS creds with the vsock address type.
>
> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

> ---
>  chardev/char-socket.c | 92 +++++++++++++++++++++++++++++++------------
>  1 file changed, 66 insertions(+), 26 deletions(-)
>
> diff --git a/chardev/char-socket.c b/chardev/char-socket.c
> index eaa8e8b68f..6669acb35f 100644
> --- a/chardev/char-socket.c
> +++ b/chardev/char-socket.c
> @@ -987,6 +987,65 @@ static gboolean socket_reconnect_timeout(gpointer opaque)
>      return false;
>  }
>
> +
> +static bool qmp_chardev_validate_socket(ChardevSocket *sock,
> +                                        SocketAddress *addr,
> +                                        Error **errp)
> +{
> +    /* Validate any options which have a dependancy on address type */
> +    switch (addr->type) {
> +    case SOCKET_ADDRESS_TYPE_FD:
> +        if (sock->has_reconnect) {
> +            error_setg(errp,
> +                       "'reconnect' option is incompatible with "
> +                       "'fd' address type");
> +            return false;
> +        }
> +        if (sock->has_tls_creds &&
> +            !(sock->has_server && sock->server)) {
> +            error_setg(errp,
> +                       "'tls_creds' option is incompatible with "
> +                       "'fd' address type as client");
> +            return false;
> +        }
> +        break;
> +
> +    case SOCKET_ADDRESS_TYPE_UNIX:
> +        if (sock->has_tls_creds) {
> +            error_setg(errp,
> +                       "'tls_creds' option is incompatible with "
> +                       "'unix' address type");
> +            return false;
> +        }
> +        break;
> +
> +    case SOCKET_ADDRESS_TYPE_INET:
> +        break;
> +
> +    case SOCKET_ADDRESS_TYPE_VSOCK:
> +        if (sock->has_tls_creds) {
> +            error_setg(errp,
> +                       "'tls_creds' option is incompatible with "
> +                       "'vsock' address type");
> +            return false;
> +        }
> +
> +    default:
> +        break;
> +    }
> +
> +    /* Validate any options which have a dependancy on client vs server */
> +    if (!(sock->has_server && sock->server)) {
> +        if (sock->has_websocket && sock->websocket) {
> +            error_setg(errp, "%s", "Websocket client is not implemented");
> +            return false;
> +        }
> +    }
> +
> +    return true;
> +}
> +
> +
>  static void qmp_chardev_open_socket(Chardev *chr,
>                                      ChardevBackend *backend,
>                                      bool *be_opened,
> @@ -1004,11 +1063,6 @@ static void qmp_chardev_open_socket(Chardev *chr,
>      QIOChannelSocket *sioc = NULL;
>      SocketAddress *addr;
>
> -    if (!is_listen && is_websock) {
> -        error_setg(errp, "%s", "Websocket client is not implemented");
> -        goto error;
> -    }
> -
>      s->is_listen = is_listen;
>      s->is_telnet = is_telnet;
>      s->is_tn3270 = is_tn3270;
> @@ -1049,10 +1103,10 @@ static void qmp_chardev_open_socket(Chardev *chr,
>
>      s->addr = addr = socket_address_flatten(sock->addr);
>
> -    if (sock->has_reconnect && addr->type == SOCKET_ADDRESS_TYPE_FD) {
> -        error_setg(errp, "'reconnect' option is incompatible with 'fd'");
> +    if (!qmp_chardev_validate_socket(sock, addr, errp)) {
>          goto error;
>      }
> +
>      qemu_chr_set_feature(chr, QEMU_CHAR_FEATURE_RECONNECTABLE);
>      /* TODO SOCKET_ADDRESS_FD where fd has AF_UNIX */
>      if (addr->type == SOCKET_ADDRESS_TYPE_UNIX) {
> @@ -1140,27 +1194,12 @@ static void qemu_chr_parse_socket(QemuOpts *opts, ChardevBackend *backend,
>          return;
>      }
>
> -    backend->type = CHARDEV_BACKEND_KIND_SOCKET;
> -    if (path) {
> -        if (tls_creds) {
> -            error_setg(errp, "TLS can only be used over TCP socket");
> -            return;
> -        }
> -    } else if (host) {
> -        if (!port) {
> -            error_setg(errp, "chardev: socket: no port given");
> -            return;
> -        }
> -    } else if (fd) {
> -        /* We don't know what host to validate against when in client mode */
> -        if (tls_creds && !is_listen) {
> -            error_setg(errp, "TLS can not be used with pre-opened client FD");
> -            return;
> -        }
> -    } else {
> -        g_assert_not_reached();
> +    if (host && !port) {
> +        error_setg(errp, "chardev: socket: no port given");
> +        return;
>      }
>
> +    backend->type = CHARDEV_BACKEND_KIND_SOCKET;
>      sock = backend->u.socket.data = g_new0(ChardevSocket, 1);
>      qemu_chr_parse_common(opts, qapi_ChardevSocket_base(sock));
>
> @@ -1178,6 +1217,7 @@ static void qemu_chr_parse_socket(QemuOpts *opts, ChardevBackend *backend,
>      sock->wait = is_waitconnect;
>      sock->has_reconnect = qemu_opt_find(opts, "reconnect");
>      sock->reconnect = reconnect;
> +    sock->has_tls_creds = tls_creds;
>      sock->tls_creds = g_strdup(tls_creds);
>
>      addr = g_new0(SocketAddressLegacy, 1);
> --
> 2.20.1
>