Added dns_use_edns0 main option.

[exim.git] / src / src / dns.c

diff --git a/src/src/dns.c b/src/src/dns.c
index a6c6d053bcbb8087e698a6ddf178611d35dfb458..bfef69927649313d01bf45c234f8a7918aa61205 100644 (file)
--- a/src/src/dns.c
+++ b/src/src/dns.c
@@ -1,10 +1,10 @@
-/* $Cambridge: exim/src/src/dns.c,v 1.16 2006/11/20 13:53:44 ph10 Exp $ */
+/* $Cambridge: exim/src/src/dns.c,v 1.21 2009/11/16 19:50:36 nm4 Exp $ */
 
 /*************************************************
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
-/* Copyright (c) University of Cambridge 1995 - 2006 */
+/* Copyright (c) University of Cambridge 1995 - 2009 */
 /* See the file NOTICE for conditions of use and distribution. */
 
 /* Functions for interfacing with the DNS. */
@@ -180,6 +180,24 @@ _res.options |= (qualify_single? RES_DEFNAMES : 0) |
                 (search_parents? RES_DNSRCH : 0);
 if (dns_retrans > 0) _res.retrans = dns_retrans;
 if (dns_retry > 0) _res.retry = dns_retry;
+
+#ifdef RES_USE_EDNS0
+if (dns_use_edns0 >= 0)
+  {
+  if (dns_use_edns0)
+    _res.options |= RES_USE_EDNS0;
+  else
+    _res.options &= ~RES_USE_EDNS0;
+  DEBUG(D_resolver)
+    debug_printf("Coerced resolver EDNS0 support %s.\n",
+        dns_use_edns0 ? "on" : "off");
+  }
+#else
+if (dns_use_edns0 >= 0)
+  DEBUG(D_resolver)
+    debug_printf("Unable to %sset EDNS0 without resolver support.\n",
+        dns_use_edns0 ? "" : "un");
+#endif
 }
 
 
@@ -462,8 +480,8 @@ Returns:    DNS_SUCCEED   successful lookup
 int
 dns_basic_lookup(dns_answer *dnsa, uschar *name, int type)
 {
-int rc = -1;
 #ifndef STAND_ALONE
+int rc = -1;
 uschar *save;
 #endif
 
@@ -505,7 +523,7 @@ For SRV records, we omit the initial _smtp._tcp. components at the start. */
 
 #ifndef STAND_ALONE   /* Omit this for stand-alone tests */
 
-if (check_dns_names_pattern[0] != 0 && type != T_PTR)
+if (check_dns_names_pattern[0] != 0 && type != T_PTR && type != T_TXT)
   {
   uschar *checkname = name;
   int ovector[3*(EXPAND_MAXN+1)];
@@ -562,7 +580,12 @@ if (running_in_test_harness)
 else
   dnsa->answerlen = res_search(CS name, C_IN, type, dnsa->answer, MAXPACKET);
 
-if (dnsa->answerlen > MAXPACKET) dnsa->answerlen = MAXPACKET;
+if (dnsa->answerlen > MAXPACKET)
+  {
+  DEBUG(D_dns) debug_printf("DNS lookup of %s (%s) resulted in overlong packet (size %d), truncating to %d.\n",
+    name, dns_text_type(type), dnsa->answerlen, MAXPACKET);
+  dnsa->answerlen = MAXPACKET;
+  }
 
 if (dnsa->answerlen < 0) switch (h_errno)
   {