From f432de2de7288c0589d1e50c2aa949a76c571794 Mon Sep 17 00:00:00 2001 From: Lorenzo Colitti Date: Wed, 28 Sep 2011 19:47:38 -0700 Subject: [PATCH] Send both A and AAAA queries if all probes fail. AI_ADDRCONFIG is currently implemented by trying to connect to well-known addresses in order to see if IPv4 and/or IPv6 connectivity is available. In some cases (e.g., walled gardens with no global connectivity) both probes can fail. If this happens, query for both IPv4 and IPv6 addresses instead of doing nothing and failing the query. Bug: 5284168 Change-Id: I4e3a69ea86fb6d839a6bd31236b98da81e5cbf45 --- libc/netbsd/net/getaddrinfo.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/libc/netbsd/net/getaddrinfo.c b/libc/netbsd/net/getaddrinfo.c index cf0503604..ace8c1a4a 100644 --- a/libc/netbsd/net/getaddrinfo.c +++ b/libc/netbsd/net/getaddrinfo.c @@ -1911,6 +1911,13 @@ _dns_getaddrinfo(void *rv, void *cb_data, va_list ap) if (pai->ai_flags & AI_ADDRCONFIG) { query_ipv6 = _have_ipv6(); query_ipv4 = _have_ipv4(); + if (query_ipv6 == 0 && query_ipv4 == 0) { + // Both our IPv4 and IPv6 connectivity probes failed, which indicates + // that we have neither an IPv4 or an IPv6 default route (and thus no + // global IPv4 or IPv6 connectivity). We might be in a walled garden. + // Throw up our arms and ask for both A and AAAA. + query_ipv6 = query_ipv4 = 1; + } } if (query_ipv6) { q.qtype = T_AAAA;