Support REQUIRETLS
[exim.git] / src / src / routers / dnslookup.c
index b4ad5eafd426f95eaa4a98d44a9b4510a76c5442..a3b0d352c2d6b24a2025fd44a21a9060c56e786f 100644 (file)
@@ -2,7 +2,7 @@
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
-/* Copyright (c) University of Cambridge 1995 - 2009 */
+/* Copyright (c) University of Cambridge 1995 - 2018 */
 /* See the file NOTICE for conditions of use and distribution. */
 
 #include "../exim.h"
@@ -20,6 +20,10 @@ optionlist dnslookup_router_options[] = {
       (void *)(offsetof(dnslookup_router_options_block, check_srv)) },
   { "fail_defer_domains", opt_stringptr,
       (void *)(offsetof(dnslookup_router_options_block, fail_defer_domains)) },
+  { "ipv4_only",          opt_stringptr,
+      (void *)(offsetof(dnslookup_router_options_block, ipv4_only)) },
+  { "ipv4_prefer",        opt_stringptr,
+      (void *)(offsetof(dnslookup_router_options_block, ipv4_prefer)) },
   { "mx_domains",         opt_stringptr,
       (void *)(offsetof(dnslookup_router_options_block, mx_domains)) },
   { "mx_fail_domains",    opt_stringptr,
@@ -44,19 +48,37 @@ address can appear in the tables drtables.c. */
 int dnslookup_router_options_count =
   sizeof(dnslookup_router_options)/sizeof(optionlist);
 
+
+#ifdef MACRO_PREDEF
+
+/* Dummy entries */
+dnslookup_router_options_block dnslookup_router_option_defaults = {0};
+void dnslookup_router_init(router_instance *rblock) {}
+int dnslookup_router_entry(router_instance *rblock, address_item *addr,
+  struct passwd *pw, int verify, address_item **addr_local,
+  address_item **addr_remote, address_item **addr_new,
+  address_item **addr_succeed) {return 0;}
+
+#else   /*!MACRO_PREDEF*/
+
+
+
+
 /* Default private options block for the dnslookup router. */
 
 dnslookup_router_options_block dnslookup_router_option_defaults = {
-  FALSE,           /* check_secondary_mx */
-  TRUE,            /* qualify_single */
-  FALSE,           /* search_parents */
-  TRUE,            /* rewrite_headers */
-  NULL,            /* widen_domains */
-  NULL,            /* mx_domains */
-  NULL,            /* mx_fail_domains */
-  NULL,            /* srv_fail_domains */
-  NULL,            /* check_srv */
-  NULL             /* fail_defer_domains */
+  .check_secondary_mx =        FALSE,
+  .qualify_single =    TRUE,
+  .search_parents =    FALSE,
+  .rewrite_headers =   TRUE,
+  .widen_domains =     NULL,
+  .mx_domains =                NULL,
+  .mx_fail_domains =   NULL,
+  .srv_fail_domains =  NULL,
+  .check_srv =         NULL,
+  .fail_defer_domains =        NULL,
+  .ipv4_only =         NULL,
+  .ipv4_prefer =       NULL,
 };
 
 
@@ -138,7 +160,7 @@ dnslookup_router_entry(
 host_item h;
 int rc;
 int widen_sep = 0;
-int whichrrs = HOST_FIND_BY_MX | HOST_FIND_BY_A;
+int whichrrs = HOST_FIND_BY_MX | HOST_FIND_BY_A | HOST_FIND_BY_AAAA;
 dnslookup_router_options_block *ob =
   (dnslookup_router_options_block *)(rblock->options_block);
 uschar *srv_service = NULL;
@@ -239,6 +261,19 @@ for (;;)
     }
   else return DECLINE;
 
+  /* Check if we must request only. or prefer, ipv4 */
+
+  if (  ob->ipv4_only
+     && expand_check_condition(ob->ipv4_only, rblock->name, US"router"))
+    flags = flags & ~HOST_FIND_BY_AAAA | HOST_FIND_IPV4_ONLY;
+  else if (search_find_defer)
+    return DEFER;
+  if (  ob->ipv4_prefer
+     && expand_check_condition(ob->ipv4_prefer, rblock->name, US"router"))
+    flags |= HOST_FIND_IPV4_FIRST;
+  else if (search_find_defer)
+    return DEFER;
+
   /* Set up the rest of the initial host item. Others may get chained on if
   there is more than one IP address. We set it up here instead of outside the
   loop so as to re-initialize if a previous try succeeded but was rejected
@@ -254,7 +289,7 @@ for (;;)
 
   /* Unfortunately, we cannot set the mx_only option in advance, because the
   DNS lookup may extend an unqualified name. Therefore, we must do the test
-  subsequently. We use the same logic as that for widen_domains above to avoid
+  stoubsequently. We use the same logic as that for widen_domains above to avoid
   requesting a header rewrite that cannot work. */
 
   if (verify != v_sender || !ob->rewrite_headers || addr->parent)
@@ -263,9 +298,11 @@ for (;;)
     if (ob->search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
     }
 
-  rc = host_find_bydns(&h, CUS rblock->ignore_target_hosts, flags, srv_service,
-    ob->srv_fail_domains, ob->mx_fail_domains,
-    &rblock->dnssec, &fully_qualified_name, &removed);
+  rc = host_find_bydns(&h, CUS rblock->ignore_target_hosts, flags,
+    srv_service, ob->srv_fail_domains, ob->mx_fail_domains,
+    &rblock->dnssec,
+    &fully_qualified_name, &removed);
+
   if (removed) setflag(addr, af_local_host_removed);
 
   /* If host found with only address records, test for the domain's being in
@@ -291,6 +328,11 @@ for (;;)
   /* Deferral returns forthwith, and anything other than failure breaks the
   loop. */
 
+  if (rc == HOST_FIND_SECURITY)
+    {
+    addr->message = US"host lookup done insecurely";
+    return DEFER;
+    }
   if (rc == HOST_FIND_AGAIN)
     {
     if (rblock->pass_on_timeout)
@@ -305,6 +347,22 @@ for (;;)
 
   if (rc != HOST_FIND_FAILED) break;
 
+  if (ob->fail_defer_domains)
+    switch(match_isinlist(fully_qualified_name,
+         CUSS &ob->fail_defer_domains, 0,
+         &domainlist_anchor, addr->domain_cache, MCL_DOMAIN, TRUE, NULL))
+      {
+      case DEFER:
+       addr->message = US"lookup defer for fail_defer_domains option";
+       return DEFER;
+
+      case OK:
+       DEBUG(D_route) debug_printf("%s router: matched fail_defer_domains\n",
+         rblock->name);
+       addr->message = US"missing MX, or all MXs point to missing A records,"
+         " and defer requested";
+       return DEFER;
+      }
   /* Check to see if the failure is the result of MX records pointing to
   non-existent domains, and if so, set an appropriate error message; the case
   of an MX or SRV record pointing to "." is another special case that we can
@@ -335,22 +393,6 @@ for (;;)
           addr->message);
         }
       }
-    if (ob->fail_defer_domains)
-      {
-      switch(match_isinlist(fully_qualified_name,
-           CUSS &ob->fail_defer_domains, 0,
-           &domainlist_anchor, addr->domain_cache, MCL_DOMAIN, TRUE, NULL))
-       {
-       case DEFER:
-         addr->message = US"lookup defer for fail_defer_domains";
-         return DEFER;
-
-       case OK:
-         DEBUG(D_route) debug_printf("%s router: matched fail_defer_domains\n",
-           rblock->name);
-         return DEFER;
-       }
-      }
     return DECLINE;
     }
 
@@ -441,6 +483,7 @@ return rf_queue_add(addr, addr_local, addr_remote, rblock, pw)?
   OK : DEFER;
 }
 
+#endif   /*!MACRO_PREDEF*/
 /* End of routers/dnslookup.c */
 /* vi: aw ai sw=2
 */