[uclibc-ng-devel] [PATCH] getaddrinfo: correct AI_V4MAPPED handling

As recently reported on the Buildroot list: http://lists.busybox.net/pipermail/buildroot/2016-March/155325.html DNS lookups with Node.js currently fails on uClibc-ng. The reason for this is the way AI_V4MAPPED is handled. According to POSIX, AI_V4MAPPED should be ignored unless ai_family is AF_INET6: http://pubs.opengroup.org/onlinepubs/9699919799/functions/freeaddrinfo.html If the AI_V4MAPPED flag is specified along with an ai_family of AF_INET6, then getaddrinfo() shall return IPv4-mapped IPv6 addresses on finding no matching IPv6 addresses (ai_addrlen shall be 16). The AI_V4MAPPED flag shall be ignored unless ai_family equals AF_INET6. uClibc-ng was also handling AI_V4MAPPED for AF_UNSPEC, fix that. Signed-off-by: Peter Korsgaard <peter(a)korsgaard.com> --- libc/inet/getaddrinfo.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/libc/inet/getaddrinfo.c b/libc/inet/getaddrinfo.c index 090d7e9..7ae32be 100644 --- a/libc/inet/getaddrinfo.c +++ b/libc/inet/getaddrinfo.c @@ -404,8 +404,7 @@ gaih_inet(const char *name, const struct gaih_service *service, struct gaih_servtuple *st; struct gaih_addrtuple *at; int rc; - int v4mapped = (req->ai_family == PF_UNSPEC || req->ai_family == PF_INET6) - && (req->ai_flags & AI_V4MAPPED); + int v4mapped = req->ai_family == PF_INET6 && (req->ai_flags & AI_V4MAPPED); unsigned seen = 0; if (req->ai_flags & AI_ADDRCONFIG) { /* "seen" is only used when AI_ADDRCONFIG is specified. -- 2.7.0