Re: [Qemu-devel] [PATCH v2 03/16] sockets: allow port to be NULL when listening on IP address

[Knut Omang <knuto@ifi.uio.no>]

On Mon, 2015-10-12 at 12:14 +0100, Daniel P. Berrange wrote:
> If the port in the SocketAddress struct is NULL, it can allow
> the kernel to automatically select a free port. This is useful
> in particular in unit tests to avoid a race trying to find a
> free port to run a test case on.

This patch seems to do a bit more than it claims ;-)

I just noticed that after a rebase a few minutes ago, all options I
have that uses this type of port syntax:

-serial telnet:ip:port
-serial tcp:ip:port
-qmp ip:port

started to ignore the port argument and instead provide a dynamic port.
Rebasing without this patch fixes the issue,

Thanks,
Knut

> 
> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
> ---
>  util/qemu-sockets.c | 18 +++++++++++++-----
>  1 file changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c
> index 9cc5bee..f9d2f6e 100644
> --- a/util/qemu-sockets.c
> +++ b/util/qemu-sockets.c
> @@ -128,12 +128,15 @@ int inet_listen_opts(QemuOpts *opts, int
> port_offset, Error **errp)
>      ai.ai_family = PF_UNSPEC;
>      ai.ai_socktype = SOCK_STREAM;
>  
> -    if ((qemu_opt_get(opts, "host") == NULL) ||
> -        (qemu_opt_get(opts, "port") == NULL)) {
> -        error_setg(errp, "host and/or port not specified");
> +    if ((qemu_opt_get(opts, "host") == NULL)) {
> +        error_setg(errp, "host not specified");
>          return -1;
>      }
> -    pstrcpy(port, sizeof(port), qemu_opt_get(opts, "port"));
> +    if (qemu_opt_get(opts, "port") != NULL) {
> +        pstrcpy(port, sizeof(port), qemu_opt_get(opts, "port"));
> +    } else {
> +        port[0] = '\0';
> +    }
>      addr = qemu_opt_get(opts, "host");
>  
>      to = qemu_opt_get_number(opts, "to", 0);
> @@ -145,6 +148,10 @@ int inet_listen_opts(QemuOpts *opts, int
> port_offset, Error **errp)
>      /* lookup */
>      if (port_offset) {
>          unsigned long long baseport;
> +        if (strlen(port) == 0) {
> +            error_setg(errp, "port not specified");
> +            return -1;
> +        }
>          if (parse_uint_full(port, &baseport, 10) < 0) {
>              error_setg(errp, "can't convert to a number: %s", port);
>              return -1;
> @@ -156,7 +163,8 @@ int inet_listen_opts(QemuOpts *opts, int
> port_offset, Error **errp)
>          }
>          snprintf(port, sizeof(port), "%d", (int)baseport +
> port_offset);
>      }
> -    rc = getaddrinfo(strlen(addr) ? addr : NULL, port, &ai, &res);
> +    rc = getaddrinfo(strlen(addr) ? addr : NULL,
> +                     strlen(port) ? port : NULL, &ai, &res);
>      if (rc != 0) {
>          error_setg(errp, "address resolution failed for %s:%s: %s",
> addr, port,
>                     gai_strerror(rc));