From 268d00bb87c544c6a89edf3b3f986ed4f639ce7a Mon Sep 17 00:00:00 2001 From: Limin Wang Date: Mon, 7 Feb 2022 08:08:18 +0800 Subject: [PATCH] avformat/udp: Fix IP_MULTICAST_TTL for BSD compatibility Suggested by zhilizhao, vlc project has solved the compatibility by the same way, so I borrowed the comments from vlc project. Fixes ticket #9449 Reviewed-by: Marton Balint Signed-off-by: Limin Wang --- libavformat/udp.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/libavformat/udp.c b/libavformat/udp.c index a2c01b3ec9..143f4b92c0 100644 --- a/libavformat/udp.c +++ b/libavformat/udp.c @@ -164,6 +164,10 @@ static int udp_set_multicast_ttl(int sockfd, int mcastTTL, { int protocol, cmd; + /* There is some confusion in the world whether IP_MULTICAST_TTL + * takes a byte or an int as an argument. + * BSD seems to indicate byte so we are going with that and use + * int and fall back to byte to be safe */ switch (addr->sa_family) { #ifdef IP_MULTICAST_TTL case AF_INET: @@ -182,8 +186,14 @@ static int udp_set_multicast_ttl(int sockfd, int mcastTTL, } if (setsockopt(sockfd, protocol, cmd, &mcastTTL, sizeof(mcastTTL)) < 0) { - ff_log_net_error(logctx, AV_LOG_ERROR, "setsockopt(IPV4/IPV6 MULTICAST TTL)"); - return ff_neterrno(); + /* BSD compatibility */ + unsigned char ttl = (unsigned char) mcastTTL; + + ff_log_net_error(logctx, AV_LOG_DEBUG, "setsockopt(IPV4/IPV6 MULTICAST TTL)"); + if (setsockopt(sockfd, protocol, cmd, &ttl, sizeof(ttl)) < 0) { + ff_log_net_error(logctx, AV_LOG_ERROR, "setsockopt(IPV4/IPV6 MULTICAST TTL)"); + return ff_neterrno(); + } } return 0;