DNS: do not skip initial two components of SRV & TLSA lookups before checking name...

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

diff --git a/src/src/dns.c b/src/src/dns.c
index ece6524d60d877a017e1de8978ca7403fa54a225..4750f1b5210ef536dc8e9711b0c8960cfae5a3ec 100644 (file)
--- a/src/src/dns.c
+++ b/src/src/dns.c
@@ -616,8 +616,10 @@ Arguments:
 Returns:     the return code
 */
 
-/*XXX the derivation of this value needs explaining */
+/* we need:  255 +1 + (max(typetext) == 5) +1 + max(chars_for_long-max) +1 */
 #define DNS_FAILTAG_MAX 290
+#define DNS_FAILNODE_SIZE \
+  (sizeof(expiring_data) + sizeof(tree_node) + DNS_FAILTAG_MAX)
 
 static int
 dns_fail_return(const uschar * name, int type, time_t expiry, int rc)
@@ -631,11 +633,9 @@ if ((previous = tree_search(tree_dns_fails, node_name)))
   e = previous->data.ptr;
 else
   {
-  new = store_get_perm(
-    sizeof(tree_node) + DNS_FAILTAG_MAX + sizeof(expiring_data), is_tainted(name));
-
+  e = store_get_perm(DNS_FAILNODE_SIZE, is_tainted(name));
+  new = (void *)(e+1);
   dns_fail_tag(new->name, name, type);
-  e = (expiring_data *)((char *)new + sizeof(tree_node) + DNS_FAILTAG_MAX);
   new->data.ptr = e;
   (void)tree_insertnode(&tree_dns_fails, new);
   }
@@ -818,34 +818,17 @@ regex has substrings that are used - the default uses a conditional.
 
 This test is omitted for PTR records. These occur only in calls from the dnsdb
 lookup, which constructs the names itself, so they should be OK. Besides,
-bitstring labels don't conform to normal name syntax. (But the aren't used any
-more.)
-
-For SRV records, we omit the initial _smtp._tcp. components at the start.
-The check has been seen to bite on the destination of a SRV lookup that
-initiall hit a CNAME, for which the next name had only two components.
-RFC2782 makes no mention of the possibiility of CNAMES, but the Wikipedia
-article on SRV says they are not a valid configuration. */
+bitstring labels don't conform to normal name syntax. (But they aren't used any
+more.) */
 
 #ifndef STAND_ALONE   /* Omit this for stand-alone tests */
 
 if (check_dns_names_pattern[0] != 0 && type != T_PTR && type != T_TXT)
   {
-  const uschar *checkname = name;
   int ovector[3*(EXPAND_MAXN+1)];
 
   dns_pattern_init();
-
-  /* For an SRV lookup, skip over the first two components (the service and
-  protocol names, which both start with an underscore). */
-
-  if (type == T_SRV || type == T_TLSA)
-    {
-    while (*checkname && *checkname++ != '.') ;
-    while (*checkname && *checkname++ != '.') ;
-    }
-
-  if (pcre_exec(regex_check_dns_names, NULL, CCS checkname, Ustrlen(checkname),
+  if (pcre_exec(regex_check_dns_names, NULL, CCS name, Ustrlen(name),
       0, PCRE_EOPT, ovector, nelem(ovector)) < 0)
     {
     DEBUG(D_dns)