From 9adccb3e767d61623f0d80bae431a2424e54f0d2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20Grubbstr=C3=B6m=20=28Grubba=29?=
<grubba@grubba.org>
Date: Thu, 24 Sep 2015 13:56:22 +0200
Subject: [PATCH] Protocols.DNS: Reduce race-condition window in do_query().
When executing do_query() in another thread than the backend thread,
there was a risk that the answer would be received and handled by
the backend thread before the retry call_out was installed. This
could cause do_query() to fail with "Lookup in destructed object."
Potential fix for [bug 7460].
---
lib/modules/Protocols.pmod/DNS.pmod | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/lib/modules/Protocols.pmod/DNS.pmod b/lib/modules/Protocols.pmod/DNS.pmod
index b1e04dba50..d2d656bc88 100644
--- a/lib/modules/Protocols.pmod/DNS.pmod
+++ b/lib/modules/Protocols.pmod/DNS.pmod
@@ -1913,8 +1913,8 @@ class async_client
}
}
- send(nameservers[nsno],53,r->req);
r->retry_co = call_out(retry, RETRY_DELAY, r, nsno+1);
+ udp::send(nameservers[nsno], 53, r->req);
}
//! Enqueue a new raw DNS request.
@@ -1936,9 +1936,9 @@ class async_client
string req=low_mkquery(lid,domain,cl,type);
object r = Request(domain, req, callback, args);
- requests[lid]=r;
- udp::send(nameservers[0],53,r->req);
r->retry_co = call_out(retry, RETRY_DELAY, r, 1);
+ requests[lid] = r;
+ udp::send(nameservers[0], 53, req);
return r;
}
}
--
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