[PATCH v2] module-rtp-recv: Only try adding the group membership for multicast addresses

[tanu.kaskinen@xxxxxxxxxxxxxxx (Tanu Kaskinen)]

On Tue, 2014-01-07 at 20:26 +0200, Laurentiu Nicola wrote:
> ---
>  src/modules/rtp/module-rtp-recv.c | 25 +++++++++++++++++--------
>  1 file changed, 17 insertions(+), 8 deletions(-)
> 
> diff --git a/src/modules/rtp/module-rtp-recv.c b/src/modules/rtp/module-rtp-recv.c
> index 41b18ab..ee161fa 100644
> --- a/src/modules/rtp/module-rtp-recv.c
> +++ b/src/modules/rtp/module-rtp-recv.c
> @@ -450,17 +450,26 @@ static int mcast_socket(const struct sockaddr* sa, socklen_t salen) {
>          goto fail;
>      }
>  
> +    r = 0;
>      if (af == AF_INET) {
> -        struct ip_mreq mr4;
> -        memset(&mr4, 0, sizeof(mr4));
> -        mr4.imr_multiaddr = ((const struct sockaddr_in*) sa)->sin_addr;
> -        r = setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mr4, sizeof(mr4));
> +        // IPv4 multicast addresses are in the 224.0.0.0-239.255.255.255 range
> +        static const uint32_t ipv4_mcast_mask = 0xe0000000;
> +
> +        if ((ntohl(((const struct sockaddr_in*) sa)->sin_addr.s_addr) & ipv4_mcast_mask) == ipv4_mcast_mask) {
> +            struct ip_mreq mr4;
> +            memset(&mr4, 0, sizeof(mr4));
> +            mr4.imr_multiaddr = ((const struct sockaddr_in*) sa)->sin_addr;
> +            r = setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mr4, sizeof(mr4));
> +        }
>  #ifdef HAVE_IPV6
>      } else if (af == AF_INET6) {
> -        struct ipv6_mreq mr6;
> -        memset(&mr6, 0, sizeof(mr6));
> -        mr6.ipv6mr_multiaddr = ((const struct sockaddr_in6*) sa)->sin6_addr;
> -        r = setsockopt(fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mr6, sizeof(mr6));
> +        // IPv6 multicase addresses have 255 as the most significant byte
> +        if (((const struct sockaddr_in6*) sa)->sin6_addr.s6_addr[0] == 0xff) {
> +            struct ipv6_mreq mr6;
> +            memset(&mr6, 0, sizeof(mr6));
> +            mr6.ipv6mr_multiaddr = ((const struct sockaddr_in6*) sa)->sin6_addr;
> +            r = setsockopt(fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mr6, sizeof(mr6));
> +        }
>  #endif
>      } else
>          pa_assert_not_reached();

Thanks, applied.

-- 
Tanu