From 0f4664d27f67c7f0597b08acd59433d6cf1a40c2 Mon Sep 17 00:00:00 2001 From: Daniel Stenberg Date: Sat, 22 Sep 2007 21:23:10 +0000 Subject: Steinar H. Gunderson fixed: Correctly clear sockets from the fd_set on in several functions (write_tcp_data, read_tcp_data, read_udp_packets) so that if it fails and the socket is closed the following code doesn't try to use the file descriptor. --- ares/CHANGES | 5 +++++ ares/ares_process.c | 21 +++++++++++++++++++++ 2 files changed, 26 insertions(+) diff --git a/ares/CHANGES b/ares/CHANGES index 4f28e3b4c..a21f1cb3f 100644 --- a/ares/CHANGES +++ b/ares/CHANGES @@ -2,6 +2,11 @@ * September 22 2007 (Daniel Stenberg) +- Steinar H. Gunderson fixed: Correctly clear sockets from the fd_set on in + several functions (write_tcp_data, read_tcp_data, read_udp_packets) so that + if it fails and the socket is closed the following code doesn't try to use + the file descriptor. + - Steinar H. Gunderson modified c-ares to now also do to DNS retries even when TCP is used since there are several edge cases where it still makes sense. diff --git a/ares/ares_process.c b/ares/ares_process.c index 66007f0fb..082fb4d84 100644 --- a/ares/ares_process.c +++ b/ares/ares_process.c @@ -167,6 +167,13 @@ static void write_tcp_data(ares_channel channel, continue; } + /* If there's an error and we close this socket, then open + * another with the same fd to talk to another server, then we + * don't want to think that it was the new socket that was + * ready. This is not disastrous, but is likely to result in + * extra system calls and confusion. */ + FD_CLR(server->tcp_socket, write_fds); + /* Count the number of send queue items. */ n = 0; for (sendreq = server->qhead; sendreq; sendreq = sendreq->next) @@ -280,6 +287,13 @@ static void read_tcp_data(ares_channel channel, fd_set *read_fds, continue; } + /* If there's an error and we close this socket, then open + * another with the same fd to talk to another server, then we + * don't want to think that it was the new socket that was + * ready. This is not disastrous, but is likely to result in + * extra system calls and confusion. */ + FD_CLR(server->tcp_socket, read_fds); + if (server->tcp_lenbuf_pos != 2) { /* We haven't yet read a length word, so read that (or @@ -370,6 +384,13 @@ static void read_udp_packets(ares_channel channel, fd_set *read_fds, continue; } + /* If there's an error and we close this socket, then open + * another with the same fd to talk to another server, then we + * don't want to think that it was the new socket that was + * ready. This is not disastrous, but is likely to result in + * extra system calls and confusion. */ + FD_CLR(server->udp_socket, read_fds); + count = sread(server->udp_socket, buf, sizeof(buf)); if (count == -1 && try_again(SOCKERRNO)) continue; -- cgit v1.2.3