From d8fddb964108e57e670d20c36e6da84796617d78 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Wed, 24 Aug 2022 20:48:47 -0400 Subject: fix fallback when ipv6 is disabled but resolv.conf has v6 nameserves apparently this code path was never tested, as it's not usual to have v6 nameservers listed on a system without v6 networking support. but it was always intended to work. when reverting to binding a v4 address, also revert the family in the sockaddr structure and the socklen for it. otherwise bind will just fail due to mismatched family/sockaddr size. fix dns resolver fallback when v6 nameservers are listed by --- src/network/res_msend.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'src') diff --git a/src/network/res_msend.c b/src/network/res_msend.c index 3e018009..105bf598 100644 --- a/src/network/res_msend.c +++ b/src/network/res_msend.c @@ -68,14 +68,15 @@ int __res_msend_rc(int nqueries, const unsigned char *const *queries, } /* Get local address and open/bind a socket */ - sa.sin.sin_family = family; fd = socket(family, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); /* Handle case where system lacks IPv6 support */ if (fd < 0 && family == AF_INET6 && errno == EAFNOSUPPORT) { fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0); family = AF_INET; + sl = sizeof sa.sin; } + sa.sin.sin_family = family; if (fd < 0 || bind(fd, (void *)&sa, sl) < 0) { if (fd >= 0) close(fd); pthread_setcancelstate(cs, 0); -- cgit 1.4.1