From 690738503fbdb3cbf1fb24edd9d25972e2d14206 Mon Sep 17 00:00:00 2001 From: Jason Glasgow Date: Wed, 30 Nov 2011 15:23:44 -0500 Subject: [PATCH] multi: handle timeouts on DNS servers by checking for new sockets If the first name server is not available, the multi interface does not invoke the socket_cb when the DNS request to the first name server timesout. Ensure that the list of sockets are always updated after calling Curl_resolver_is_resolved. This bug can be reproduced if Curl is complied with --enable_ares and your code uses the multi socket interfaces and the CURLMOPT_SOCKETFUNCTION option. To test try: iptables -I INPUT \ -s $(sed -n -e '/name/{s/.* //p;q}' /etc/resolv.conf)/32 \ -j REJECT and then run a program which uses the multi-interface. --- lib/multi.c | 13 ++++++++----- 1 files changed, 8 insertions(+), 5 deletions(-) diff --git a/lib/multi.c b/lib/multi.c index ae70851..3059e49 100644 --- a/lib/multi.c +++ b/lib/multi.c @@ -1085,12 +1085,15 @@ static CURLMcode multi_runsingle(struct Curl_multi *multi, /* check if we have the name resolved by now */ easy->result = Curl_resolver_is_resolved(easy->easy_conn, &dns); - if(dns) { - /* Update sockets here. Mainly because the socket(s) may have been - closed and the application thus needs to be told, even if it is - likely that the same socket(s) will again be used further down. */ - singlesocket(multi, easy); + /* Update sockets here, because the socket(s) may have been + closed and the application thus needs to be told, even if it + is likely that the same socket(s) will again be used further + down. If the name has not yet been resolved, it is likely + that new sockets have been opened in an attempt to contact + another resolver. */ + singlesocket(multi, easy); + if(dns) { /* Perform the next step in the connection phase, and then move on to the WAITCONNECT state */ easy->result = Curl_async_resolved(easy->easy_conn, -- 1.7.3.1