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0b2dfd |
From 7af6c0ef6354288f8a8240e5ca44a55ab4c6cf91 Mon Sep 17 00:00:00 2001
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0b2dfd |
From: Alexey Tikhonov <atikhono@redhat.com>
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0b2dfd |
Date: Thu, 15 Jun 2023 18:04:50 +0200
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0b2dfd |
Subject: [PATCH]
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0b2dfd |
https://github.com/c-ares/c-ares/commit/b9b8413cfdb70a3f99e1573333b23052d57ec1ae
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0b2dfd |
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0b2dfd |
---
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0b2dfd |
ares_process.c | 41 ++++++++++++++++++++++++-----------------
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0b2dfd |
1 file changed, 24 insertions(+), 17 deletions(-)
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0b2dfd |
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0b2dfd |
diff --git a/ares_process.c b/ares_process.c
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0b2dfd |
index bbeca5e..ad7e862 100644
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0b2dfd |
--- a/ares_process.c
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0b2dfd |
+++ b/ares_process.c
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0b2dfd |
@@ -416,7 +416,7 @@ static void read_udp_packets(ares_channel channel, fd_set *read_fds,
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0b2dfd |
{
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0b2dfd |
struct server_state *server;
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0b2dfd |
int i;
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0b2dfd |
- ssize_t count;
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0b2dfd |
+ ssize_t read_len;
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0b2dfd |
unsigned char buf[MAXENDSSZ + 1];
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0b2dfd |
#ifdef HAVE_RECVFROM
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0b2dfd |
ares_socklen_t fromlen;
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0b2dfd |
@@ -459,36 +459,43 @@ static void read_udp_packets(ares_channel channel, fd_set *read_fds,
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0b2dfd |
/* To reduce event loop overhead, read and process as many
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0b2dfd |
* packets as we can. */
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0b2dfd |
do {
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0b2dfd |
- if (server->udp_socket == ARES_SOCKET_BAD)
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0b2dfd |
- count = 0;
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0b2dfd |
-
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0b2dfd |
- else {
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0b2dfd |
+ if (server->udp_socket == ARES_SOCKET_BAD) {
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0b2dfd |
+ read_len = -1;
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0b2dfd |
+ } else {
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0b2dfd |
#ifdef HAVE_RECVFROM
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0b2dfd |
- if (server->addr.family == AF_INET)
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0b2dfd |
+ if (server->addr.family == AF_INET) {
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0b2dfd |
fromlen = sizeof(from.sa4);
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0b2dfd |
- else
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0b2dfd |
+ } else {
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0b2dfd |
fromlen = sizeof(from.sa6);
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0b2dfd |
- count = (ssize_t)recvfrom(server->udp_socket, (void *)buf,
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0b2dfd |
- sizeof(buf), 0, &from.sa, &fromlen);
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0b2dfd |
+ }
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0b2dfd |
+ read_len = (ssize_t)recvfrom(server->udp_socket, (void *)buf,
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0b2dfd |
+ sizeof(buf), 0, &from.sa, &fromlen);
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0b2dfd |
#else
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0b2dfd |
- count = sread(server->udp_socket, buf, sizeof(buf));
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0b2dfd |
+ read_len = sread(server->udp_socket, buf, sizeof(buf));
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0b2dfd |
#endif
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0b2dfd |
}
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0b2dfd |
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0b2dfd |
- if (count == -1 && try_again(SOCKERRNO))
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0b2dfd |
+ if (read_len == 0) {
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0b2dfd |
+ /* UDP is connectionless, so result code of 0 is a 0-length UDP
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0b2dfd |
+ * packet, and not an indication the connection is closed like on
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0b2dfd |
+ * tcp */
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0b2dfd |
continue;
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0b2dfd |
- else if (count <= 0)
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0b2dfd |
+ } else if (read_len < 0) {
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0b2dfd |
+ if (try_again(SOCKERRNO))
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0b2dfd |
+ continue;
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0b2dfd |
+
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0b2dfd |
handle_error(channel, i, now);
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0b2dfd |
#ifdef HAVE_RECVFROM
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0b2dfd |
- else if (!same_address(&from.sa, &server->addr))
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0b2dfd |
+ } else if (!same_address(&from.sa, &server->addr)) {
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0b2dfd |
/* The address the response comes from does not match the address we
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0b2dfd |
* sent the request to. Someone may be attempting to perform a cache
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0b2dfd |
* poisoning attack. */
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0b2dfd |
- break;
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0b2dfd |
+ continue;
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0b2dfd |
#endif
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0b2dfd |
- else
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0b2dfd |
- process_answer(channel, buf, (int)count, i, 0, now);
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0b2dfd |
- } while (count > 0);
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0b2dfd |
+ } else {
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0b2dfd |
+ process_answer(channel, buf, (int)read_len, i, 0, now);
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0b2dfd |
+ }
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0b2dfd |
+ } while (read_len >= 0);
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0b2dfd |
}
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0b2dfd |
}
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0b2dfd |
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0b2dfd |
--
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0b2dfd |
2.38.1
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0b2dfd |
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