From 695fc3dbd70969bb27ce2816c90fd650fc94300b Mon Sep 17 00:00:00 2001
From: Sean Bright <sean.bright@gmail.com>
Date: Mon, 6 Sep 2021 12:37:08 -0400
Subject: [PATCH] dns.c: Load IPv6 DNS resolvers if configured.
IPv6 nameserver addresses are stored in different part of the
__res_state structure, so look there if we appear to have support for
it.
ASTERISK-28004 #close
Change-Id: I67067077d8a406ee996664518d9c8fbf11f6977d
---
configure | 11 +++++++++++
configure.ac | 3 ++-
include/asterisk/autoconfig.h.in | 3 +++
main/dns.c | 17 ++++++++++++++++-
4 files changed, 32 insertions(+), 2 deletions(-)
diff --git a/configure b/configure
index 7d45eb869a..d6ae5799a9 100755
--- a/configure
+++ b/configure
@@ -18657,6 +18657,17 @@ $as_echo "no" >&6; }
fi
rm -f core conftest.err conftest.$ac_objext \
conftest$ac_exeext conftest.$ac_ext
+ ac_fn_c_check_member "$LINENO" "struct __res_state" "_u._ext.nsaddrs" "ac_cv_member_struct___res_state__u__ext_nsaddrs" "#include <resolv.h>
+"
+if test "x$ac_cv_member_struct___res_state__u__ext_nsaddrs" = xyes; then :
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_STRUCT___RES_STATE__U__EXT_NSADDRS 1
+_ACEOF
+
+
+fi
+
else
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
$as_echo "no" >&6; }
diff --git a/configure.ac b/configure.ac
index ea6080dd3a..e61a96fc42 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1459,7 +1459,8 @@ AC_LINK_IFELSE(
AC_MSG_RESULT(yes)
AC_DEFINE([HAVE_RES_CLOSE], 1, [Define to 1 if your system has the close resolver function.]),
AC_MSG_RESULT(no)
- ),
+ )
+ AC_CHECK_MEMBERS([struct __res_state._u._ext.nsaddrs], [], [], [[#include <resolv.h>]]),
AC_MSG_RESULT(no)
)
diff --git a/include/asterisk/autoconfig.h.in b/include/asterisk/autoconfig.h.in
index fc3a9bdb00..776074d4ff 100644
--- a/include/asterisk/autoconfig.h.in
+++ b/include/asterisk/autoconfig.h.in
@@ -1052,6 +1052,9 @@
/* Define to 1 if `uid' is a member of `struct ucred'. */
#undef HAVE_STRUCT_UCRED_UID
+/* Define to 1 if `_u._ext.nsaddrs' is a member of `struct __res_state'. */
+#undef HAVE_STRUCT___RES_STATE__U__EXT_NSADDRS
+
/* Define to 1 if you have the `swapctl' function. */
#undef HAVE_SWAPCTL
diff --git a/main/dns.c b/main/dns.c
index 782d4a8f8d..9cf0cf41de 100644
--- a/main/dns.c
+++ b/main/dns.c
@@ -605,7 +605,22 @@ struct ao2_container *ast_dns_get_nameservers(void)
#endif
for (i = 0; i < state->nscount; i++) {
- ast_str_container_add(nameservers, ast_inet_ntoa(state->nsaddr_list[i].sin_addr));
+ char addr[INET6_ADDRSTRLEN];
+ const char *addrp = NULL;
+
+ /* glibc sets sin_family to 0 when the nameserver is an IPv6 address */
+ if (state->nsaddr_list[i].sin_family) {
+ addrp = inet_ntop(AF_INET, &state->nsaddr_list[i].sin_addr, addr, sizeof(addr));
+#if defined(HAVE_RES_NINIT) && defined(HAVE_STRUCT___RES_STATE__U__EXT_NSADDRS)
+ } else if (state->_u._ext.nsaddrs[i]) {
+ addrp = inet_ntop(AF_INET6, &state->_u._ext.nsaddrs[i]->sin6_addr, addr, sizeof(addr));
+#endif
+ }
+
+ if (addrp) {
+ ast_debug(1, "Discovered nameserver: %s\n", addrp);
+ ast_str_container_add(nameservers, addrp);
+ }
}
#ifdef HAVE_RES_NINIT
--
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