From 2a6148716c7e687c19b8f57f83f49c8492537514 Mon Sep 17 00:00:00 2001
From: Yang Tse <yangsita@gmail.com>
Date: Tue, 26 Aug 2008 03:08:27 +0000
Subject: [PATCH] Functionality only possible if recvfrom() is available.
---
ares/ares_process.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/ares/ares_process.c b/ares/ares_process.c
index 0a99a1bb4f..824640eaea 100644
--- a/ares/ares_process.c
+++ b/ares/ares_process.c
@@ -429,8 +429,10 @@ static void read_udp_packets(ares_channel channel, fd_set *read_fds,
int i;
ssize_t count;
unsigned char buf[PACKETSZ + 1];
+#ifdef HAVE_RECVFROM
struct sockaddr_in from;
socklen_t fromlen;
+#endif
if(!read_fds && (read_fd == ARES_SOCKET_BAD))
/* no possible action */
@@ -464,23 +466,24 @@ static void read_udp_packets(ares_channel channel, fd_set *read_fds,
/* To reduce event loop overhead, read and process as many
* packets as we can. */
do {
- /* Must memset 'from' to 0 as recvfrom() on some systems may
- * not use 'from' at all if it doesn't support receiving the
- * source address of the response */
- memset(&from, 0, sizeof(from));
+#ifdef HAVE_RECVFROM
fromlen = sizeof(from);
count = (ssize_t)recvfrom(server->udp_socket, (void *)buf, sizeof(buf),
0, (struct sockaddr *)&from, &fromlen);
+#else
+ count = sread(server->udp_socket, buf, sizeof(buf));
+#endif
if (count == -1 && try_again(SOCKERRNO))
continue;
else if (count <= 0)
handle_error(channel, i, now);
- else if (fromlen && from.sin_addr.s_addr != 0 &&
- from.sin_addr.s_addr != server->addr.s_addr)
+#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;
+#endif
else
process_answer(channel, buf, (int)count, i, 0, now);
} while (count > 0);
--
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