From be7c4f5806a29298988601f9bac5a4ebab6c000c Mon Sep 17 00:00:00 2001
From: Jakub Hrozek <jhrozek@redhat.com>
Date: Mon, 1 Feb 2010 21:23:59 +0100
Subject: Allow the use of IPv6 nameservers

This patch allows the use of IPv6 addresses for nameserves in both
/etc/resolv.conf and by using the ares_set_nameservers() API.
---
 ares_process.c | 95 ++++++++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 72 insertions(+), 23 deletions(-)

(limited to 'ares_process.c')

diff --git a/ares_process.c b/ares_process.c
index 71f9394..65b95f4 100644
--- a/ares_process.c
+++ b/ares_process.c
@@ -434,7 +434,7 @@ static void read_udp_packets(ares_channel channel, fd_set *read_fds,
   ssize_t count;
   unsigned char buf[PACKETSZ + 1];
 #ifdef HAVE_RECVFROM
-  struct sockaddr_in from;
+  struct sockaddr_storage from;
   ares_socklen_t fromlen;
 #endif
 
@@ -480,16 +480,29 @@ static void read_udp_packets(ares_channel channel, fd_set *read_fds,
         if (count == -1 && try_again(SOCKERRNO))
           continue;
         else if (count <= 0)
-          handle_error(channel, i, now);
+          {
+            handle_error(channel, i, now);
+            break;
+          }
 #ifdef HAVE_RECVFROM
-        else if (from.sin_addr.s_addr != server->addr.s_addr)
-          /* Address response came from did not match the address
-           * we sent the request to.  Someone may be attempting
-           * to perform a cache poisoning attack */
-          break;
+        /* Check if address response came from did match the address
+         * we sent the request to.  Someone may be attempting
+         * to perform a cache poisoning attack */
+        else if (from.ss_family == AF_INET)
+          {
+              if (((struct sockaddr_in *) &from)->sin_addr.s_addr !=
+                   server->addr.addrV4.s_addr)
+                break;
+          }
+        else if (from.ss_family == AF_INET6)
+          {
+              if (memcmp(((struct sockaddr_in6 *) &from)->sin6_addr.s6_addr,
+                         server->addr.addrV6.s6_addr,
+                         16))
+                break;
+          }
 #endif
-        else
-          process_answer(channel, buf, (int)count, i, 0, now);
+        process_answer(channel, buf, (int)count, i, 0, now);
        } while (count > 0);
     }
 }
@@ -889,14 +902,44 @@ static int configure_socket(ares_socket_t s, ares_channel channel)
   return 0;
  }
 
+static int prepare_addrinfo(struct server_state *server, int port,
+                            struct sockaddr_storage *addr)
+{
+  const unsigned short sh_port = (unsigned short)(port & 0xffff);
+  int rc = ARES_SUCCESS;
+
+  switch (server->addr.family)
+    {
+    case AF_INET:
+      ((struct sockaddr_in *) addr)->sin_family = AF_INET;
+      ((struct sockaddr_in *) addr)->sin_port = sh_port;
+      ((struct sockaddr_in *) addr)->sin_addr.s_addr = server->addr.addrV4.s_addr;
+      break;
+
+    case AF_INET6:
+      ((struct sockaddr_in6 *) addr)->sin6_family = AF_INET6;
+      ((struct sockaddr_in6 *) addr)->sin6_port = sh_port;
+      memcpy(((struct sockaddr_in6 *) addr)->sin6_addr.s6_addr,
+             server->addr.addrV6.s6_addr,
+             16);
+      break;
+
+    default:
+      rc = ARES_EBADFAMILY;
+      break;
+    }
+
+  return rc;
+}
+
 static int open_tcp_socket(ares_channel channel, struct server_state *server)
 {
   ares_socket_t s;
   int opt;
-  struct sockaddr_in sockin;
+  struct sockaddr_storage addr;
 
   /* Acquire a socket. */
-  s = socket(AF_INET, SOCK_STREAM, 0);
+  s = socket(server->addr.family, SOCK_STREAM, 0);
   if (s == ARES_SOCKET_BAD)
     return -1;
 
@@ -923,12 +966,15 @@ static int open_tcp_socket(ares_channel channel, struct server_state *server)
     }
 #endif
 
+  if (prepare_addrinfo(server, channel->tcp_port, &addr) != ARES_SUCCESS)
+    {
+       sclose(s);
+       return -1;
+    }
+
   /* Connect to the server. */
-  memset(&sockin, 0, sizeof(sockin));
-  sockin.sin_family = AF_INET;
-  sockin.sin_addr = server->addr;
-  sockin.sin_port = (unsigned short)(channel->tcp_port & 0xffff);
-  if (connect(s, (struct sockaddr *) &sockin, sizeof(sockin)) == -1)
+  if (connect(s, (struct sockaddr *) &addr,
+              sizeof(struct sockaddr_storage)) == -1)
     {
       int err = SOCKERRNO;
 
@@ -960,10 +1006,10 @@ static int open_tcp_socket(ares_channel channel, struct server_state *server)
 static int open_udp_socket(ares_channel channel, struct server_state *server)
 {
   ares_socket_t s;
-  struct sockaddr_in sockin;
+  struct sockaddr_storage addr;
 
   /* Acquire a socket. */
-  s = socket(AF_INET, SOCK_DGRAM, 0);
+  s = socket(server->addr.family, SOCK_DGRAM, 0);
   if (s == ARES_SOCKET_BAD)
     return -1;
 
@@ -974,12 +1020,15 @@ static int open_udp_socket(ares_channel channel, struct server_state *server)
        return -1;
     }
 
+  if (prepare_addrinfo(server, channel->udp_port, &addr) != ARES_SUCCESS)
+    {
+       sclose(s);
+       return -1;
+    }
+
   /* Connect to the server. */
-  memset(&sockin, 0, sizeof(sockin));
-  sockin.sin_family = AF_INET;
-  sockin.sin_addr = server->addr;
-  sockin.sin_port = (unsigned short)(channel->udp_port & 0xffff);
-  if (connect(s, (struct sockaddr *) &sockin, sizeof(sockin)) == -1)
+  if (connect(s, (struct sockaddr *) &addr,
+              sizeof(struct sockaddr_storage)) == -1)
     {
       int err = SOCKERRNO;
 
-- 
cgit