[FFmpeg-devel] [PATCH] Fix setsockopt IP_MULTICAST_TTL on OpenBSD

[lance.lmwang at gmail.com]

On Wed, Jan 12, 2022 at 12:13:13AM -0500, Brad Smith wrote:
> Fix setsockopt() usage on OpenBSD with IP_MULTICAST_TTL. The field
> type should be an unsigned char on anything but Linux.
> 
> 
> diff --git a/libavformat/udp.c b/libavformat/udp.c
> index 180d96a988..29aa865fff 100644
> --- a/libavformat/udp.c
> +++ b/libavformat/udp.c
> @@ -163,7 +163,13 @@ static int udp_set_multicast_ttl(int sockfd, int mcastTTL,
>  {
>  #ifdef IP_MULTICAST_TTL
>      if (addr->sa_family == AF_INET) {
> -        if (setsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_TTL, &mcastTTL, sizeof(mcastTTL)) < 0) {
> +#ifdef __linux__
> +        int ttl = mcastTTL;
> +#else
> +        unsigned char ttl = mcastTTL;
> +#endif


I don't have BSD system for test, but I prefer to use socklen_t, please try with my proposal patch:

---
 libavformat/udp.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/libavformat/udp.c b/libavformat/udp.c
index 83c042d079..b9baa0a803 100644
--- a/libavformat/udp.c
+++ b/libavformat/udp.c
@@ -164,7 +164,9 @@ static int udp_set_multicast_ttl(int sockfd, int mcastTTL,
 {
 #ifdef IP_MULTICAST_TTL
     if (addr->sa_family == AF_INET) {
-        if (setsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_TTL, &mcastTTL, sizeof(mcastTTL)) < 0) {
+        socklen_t ttl = mcastTTL;
+
+        if (setsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0) {
             ff_log_net_error(logctx, AV_LOG_ERROR, "setsockopt(IP_MULTICAST_TTL)");
             return ff_neterrno();


> +
> +        if (setsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0) {
>              ff_log_net_error(NULL, AV_LOG_ERROR, "setsockopt(IP_MULTICAST_TTL)");
>              return ff_neterrno();
>          }
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> 
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".

-- 
Thanks,
Limin Wang