From: Amos Jeffries <squid3@treenet.co.nz>
Date: Sun, 3 Apr 2011 11:04:25 +0000 (-0600)
Subject: Make DNS report failure on all packet construction errors
X-Git-Tag: SQUID_3_1_12~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=788cc3d3e58af56ab690afd9c7d69f67779176b8;p=thirdparty%2Fsquid.git

Make DNS report failure on all packet construction errors

The attached patch alters the DNS lookup behaviour to abort with an error
in ALL cases where the rfc1035 library generates an error (negative result).

I'm not sure there is any noticable effect other than better code. The
error case *should* in old code be picked up on the initial packet
construction rather than the repeat packet. This may have been incorrect
given that the packet type is changing between A/AAAA.
---

diff --git a/src/dns_internal.cc b/src/dns_internal.cc
index aa7f187f5c..4bd88db07d 100644
--- a/src/dns_internal.cc
+++ b/src/dns_internal.cc
@@ -103,7 +103,7 @@ struct _idns_query {
     char buf[RESOLV_BUFSZ];
     char name[NS_MAXDNAME + 1];
     char orig[NS_MAXDNAME + 1];
-    size_t sz;
+    ssize_t sz;
     unsigned short id;
     int nsends;
     int need_vc;
@@ -1050,6 +1050,14 @@ idnsGrokReply(const char *buf, size_t sz)
                 debugs(78, 3, "idnsGrokReply: Trying A Query for " << q->name);
                 q->sz = rfc3596BuildAQuery(q->name, q->buf, sizeof(q->buf), q->id, &q->query);
             }
+
+            if (q->sz < 0) {
+                /* problem with query data -- query not sent */
+                idnsCallback(static_cast<idns_query *>(q->callback_data), NULL, 0, "Internal error");
+                cbdataFree(q);
+                return;
+            }
+
             idnsCacheQuery(q);
             idnsSendQuery(q);
             return;
@@ -1088,6 +1096,14 @@ idnsGrokReply(const char *buf, size_t sz)
         rfc1035SetQueryID(q->buf, q->id);
         q->sz = rfc3596BuildAQuery(q->name, q->buf, sizeof(q->buf), q->id, &q->query);
         q->need_A = false;
+
+        if (q->sz < 0) {
+            /* problem with query data -- query not sent */
+            idnsCallback(static_cast<idns_query *>(q->callback_data), NULL, 0, "Internal error");
+            cbdataFree(q);
+            return;
+        }
+
         idnsCacheQuery(q);
         idnsSendQuery(q);
         return;