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

@@ -1296,7 +1296,6 @@ BUILD_OS
 BUILD_VENDOR
 BUILD_CPU
 BUILD_PLATFORM
-astcachedir
 astvarrundir
 astlogdir
 astspooldir
@@ -1309,6 +1308,7 @@ astmoddir
 astlibdir
 astheaderdir
 astetcdir
+astcachedir
 astsbindir
 EGREP
 GREP
@@ -1349,6 +1349,7 @@ infodir
 docdir
 oldincludedir
 includedir
+runstatedir
 localstatedir
 sharedstatedir
 sysconfdir
@@ -1538,6 +1539,7 @@ datadir='${datarootdir}'
 sysconfdir='${prefix}/etc'
 sharedstatedir='${prefix}/com'
 localstatedir='${prefix}/var'
+runstatedir='${localstatedir}/run'
 includedir='${prefix}/include'
 oldincludedir='/usr/include'
 docdir='${datarootdir}/doc/${PACKAGE_TARNAME}'
@@ -1790,6 +1792,15 @@ do
   | -silent | --silent | --silen | --sile | --sil)
     silent=yes ;;
+  -runstatedir | --runstatedir | --runstatedi | --runstated \
+  | --runstate | --runstat | --runsta | --runst | --runs \
+  | --run | --ru | --r)
+    ac_prev=runstatedir ;;
+  -runstatedir=* | --runstatedir=* | --runstatedi=* | --runstated=* \
+  | --runstate=* | --runstat=* | --runsta=* | --runst=* | --runs=* \
+  | --run=* | --ru=* | --r=*)
+    runstatedir=$ac_optarg ;;
+
   -sbindir | --sbindir | --sbindi | --sbind | --sbin | --sbi | --sb)
     ac_prev=sbindir ;;
   -sbindir=* | --sbindir=* | --sbindi=* | --sbind=* | --sbin=* \
@@ -1927,7 +1938,7 @@ fi
 for ac_var in	exec_prefix prefix bindir sbindir libexecdir datarootdir \
 		datadir sysconfdir sharedstatedir localstatedir includedir \
 		oldincludedir docdir infodir htmldir dvidir pdfdir psdir \
-		libdir localedir mandir
+		libdir localedir mandir runstatedir
 do
   eval ac_val=\$$ac_var
   # Remove trailing slashes.
@@ -2080,6 +2091,7 @@ Fine tuning of the installation directories:
   --sysconfdir=DIR        read-only single-machine data [PREFIX/etc]
   --sharedstatedir=DIR    modifiable architecture-independent data [PREFIX/com]
   --localstatedir=DIR     modifiable single-machine data [PREFIX/var]
+  --runstatedir=DIR       modifiable per-process data [LOCALSTATEDIR/run]
   --libdir=DIR            object code libraries [EPREFIX/lib]
   --includedir=DIR        C header files [PREFIX/include]
   --oldincludedir=DIR     C header files for non-gcc [/usr/include]
@@ -10848,6 +10860,7 @@ fi
+
     MISDN_DESCRIP="mISDN user"
     MISDN_OPTION="misdn"
     PBX_MISDN=0
@@ -14688,7 +14701,7 @@ else
     We can't simply define LARGE_OFF_T to be 9223372036854775807,
     since some C++ compilers masquerading as C compilers
     incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
+#define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + (((off_t) 1 << 31) << 31))
   int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
 		       && LARGE_OFF_T % 2147483647 == 1)
 		      ? 1 : -1];
@@ -14734,7 +14747,7 @@ else
     We can't simply define LARGE_OFF_T to be 9223372036854775807,
     since some C++ compilers masquerading as C compilers
     incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
+#define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + (((off_t) 1 << 31) << 31))
   int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
 		       && LARGE_OFF_T % 2147483647 == 1)
 		      ? 1 : -1];
@@ -14758,7 +14771,7 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
     We can't simply define LARGE_OFF_T to be 9223372036854775807,
     since some C++ compilers masquerading as C compilers
     incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
+#define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + (((off_t) 1 << 31) << 31))
   int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
 		       && LARGE_OFF_T % 2147483647 == 1)
 		      ? 1 : -1];
@@ -14803,7 +14816,7 @@ else
     We can't simply define LARGE_OFF_T to be 9223372036854775807,
     since some C++ compilers masquerading as C compilers
     incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
+#define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + (((off_t) 1 << 31) << 31))
   int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
 		       && LARGE_OFF_T % 2147483647 == 1)
 		      ? 1 : -1];
@@ -14827,7 +14840,7 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
     We can't simply define LARGE_OFF_T to be 9223372036854775807,
     since some C++ compilers masquerading as C compilers
     incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
+#define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + (((off_t) 1 << 31) << 31))
   int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
 		       && LARGE_OFF_T % 2147483647 == 1)
 		      ? 1 : -1];
@@ -16127,6 +16140,8 @@ main ()
     if (*(data + i) != *(data3 + i))
       return 14;
   close (fd);
+  free (data);
+  free (data3);
   return 0;
 }
 _ACEOF
@@ -18957,6 +18972,17 @@ $as_echo "no" >&6; }
 fi
 rm -f core conftest.err conftest.$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; }

configure.ac

@@ -1466,7 +1466,8 @@ 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)
 )
 

include/asterisk/autoconfig.h.in

@@ -1073,6 +1073,9 @@
 /* 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 mISDN Supplemental Services library. */
 #undef HAVE_SUPPSERV
 

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