From 7cef4817d6d6d61a1166ed7dfc13537b95c65970 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Thu, 15 Sep 2016 13:20:51 +0200 Subject: [PATCH] libbb:/send_to_from: do not require that "to" should have the same AF. Closes 9146 Signed-off-by: Denys Vlasenko --- libbb/udp_io.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/libbb/udp_io.c b/libbb/udp_io.c index a32af9bd2..6e3ef484e 100644 --- a/libbb/udp_io.c +++ b/libbb/udp_io.c @@ -70,7 +70,13 @@ send_to_from(int fd, void *buf, size_t len, int flags, msg.msg_flags = flags; cmsgptr = CMSG_FIRSTHDR(&msg); - if (to->sa_family == AF_INET && from->sa_family == AF_INET) { + /* + * Users report that to->sa_family can be AF_INET6 too, + * if "to" was acquired by recv_from_to(). IOW: recv_from_to() + * was seen showing IPv6 "from" even when the destination + * of received packet (our local address) was IPv4. + */ + if (/* to->sa_family == AF_INET && */ from->sa_family == AF_INET) { struct in_pktinfo *pktptr; cmsgptr->cmsg_level = IPPROTO_IP; cmsgptr->cmsg_type = IP_PKTINFO; @@ -86,7 +92,7 @@ send_to_from(int fd, void *buf, size_t len, int flags, pktptr->ipi_spec_dst = ((struct sockaddr_in*)from)->sin_addr; } # if ENABLE_FEATURE_IPV6 && defined(IPV6_PKTINFO) - else if (to->sa_family == AF_INET6 && from->sa_family == AF_INET6) { + else if (/* to->sa_family == AF_INET6 && */ from->sa_family == AF_INET6) { struct in6_pktinfo *pktptr; cmsgptr->cmsg_level = IPPROTO_IPV6; cmsgptr->cmsg_type = IPV6_PKTINFO; -- 2.25.1