Import Upstream version 4.92
[hcoop/debian/exim4.git] / src / routers / rf_lookup_hostlist.c
index 0eae31e..0527566 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 - 2015 */
 /* See the file NOTICE for conditions of use and distribution. */
 
 
@@ -35,7 +35,8 @@ Arguments:
   rblock               the router block
   addr                 the address being routed
   ignore_target_hosts  list of hosts to ignore
-  lookup_type          lk_default or lk_byname or lk_bydns
+  lookup_type          LK_DEFAULT or LK_BYNAME or LK_BYDNS,
+                      plus LK_IPV4_{ONLY,PREFER}
   hff_code             what to do for host find failed
   addr_new             passed to rf_self_action for self=reroute
 
@@ -61,14 +62,13 @@ host, omit it and any subsequent hosts - i.e. treat the list like an ordered
 list of MX hosts. If the first host is the local host, act according to the
 "self" option in the configuration. */
 
-prev = NULL;
-for (h = addr->host_list; h != NULL; h = next_h)
+for (prev = NULL, h = addr->host_list; h; h = next_h)
   {
-  uschar *canonical_name;
-  int rc, len, port;
+  const uschar *canonical_name;
+  int rc, len, port, mx, sort_key;
 
   next_h = h->next;
-  if (h->address != NULL) { prev = h; continue; }
+  if (h->address) { prev = h; continue; }
 
   DEBUG(D_route|D_host_lookup)
     debug_printf("finding IP address for %s\n", h->name);
@@ -78,32 +78,45 @@ for (h = addr->host_list; h != NULL; h = next_h)
 
   port = host_item_get_port(h);
 
+  /* Store the previous mx and sort_key values, which were assigned in
+  host_build_hostlist and will be overwritten by host_find_bydns. */
+
+  mx = h->mx;
+  sort_key = h->sort_key;
+
   /* If the name ends with "/MX", we interpret it to mean "the list of hosts
-  pointed to by MX records with this name". */
+  pointed to by MX records with this name", and the MX record values override
+  the ordering from host_build_hostlist. */
 
   len = Ustrlen(h->name);
   if (len > 3 && strcmpic(h->name + len - 3, US"/mx") == 0)
     {
+    int whichrrs = lookup_type & LK_IPV4_ONLY
+      ? HOST_FIND_BY_MX | HOST_FIND_IPV4_ONLY
+      : lookup_type & LK_IPV4_PREFER
+      ? HOST_FIND_BY_MX | HOST_FIND_IPV4_FIRST
+      : HOST_FIND_BY_MX;
+
     DEBUG(D_route|D_host_lookup)
       debug_printf("doing DNS MX lookup for %s\n", h->name);
 
+    mx = MX_NONE;
     h->name = string_copyn(h->name, len - 3);
     rc = host_find_bydns(h,
         ignore_target_hosts,
-        HOST_FIND_BY_MX,                /* look only for MX records */
-        NULL,                           /* SRV service not relevant */
-        NULL,                           /* failing srv domains not relevant */
-        NULL,                           /* no special mx failing domains */
-       NULL,                           /* no dnssec request XXX ? */
-       NULL,                           /* no dnssec require XXX ? */
-        NULL,                           /* fully_qualified_name */
-        NULL);                          /* indicate local host removed */
+        whichrrs,                      /* look only for MX records */
+        NULL,                          /* SRV service not relevant */
+        NULL,                          /* failing srv domains not relevant */
+        NULL,                          /* no special mx failing domains */
+        &rblock->dnssec,               /* dnssec request/require */
+        NULL,                          /* fully_qualified_name */
+        NULL);                         /* indicate local host removed */
     }
 
   /* If explicitly configured to look up by name, or if the "host name" is
   actually an IP address, do a byname lookup. */
 
-  else if (lookup_type == lk_byname || string_is_ip_address(h->name, NULL) != 0)
+  else if (lookup_type & LK_BYNAME || string_is_ip_address(h->name, NULL) != 0)
     {
     DEBUG(D_route|D_host_lookup) debug_printf("calling host_find_byname\n");
     rc = host_find_byname(h, ignore_target_hosts, HOST_FIND_QUALIFY_SINGLE,
@@ -117,29 +130,41 @@ for (h = addr->host_list; h != NULL; h = next_h)
   else
     {
     BOOL removed;
+    int whichrrs = lookup_type & LK_IPV4_ONLY
+      ? HOST_FIND_BY_A
+      : lookup_type & LK_IPV4_PREFER
+      ? HOST_FIND_BY_A | HOST_FIND_BY_AAAA | HOST_FIND_IPV4_FIRST
+      : HOST_FIND_BY_A | HOST_FIND_BY_AAAA;
+
     DEBUG(D_route|D_host_lookup) debug_printf("doing DNS lookup\n");
-    rc = host_find_bydns(h, ignore_target_hosts, HOST_FIND_BY_A, NULL, NULL,
-      NULL,
-      NULL, NULL,      /*XXX dnssec? */
-      &canonical_name, &removed);
-    if (rc == HOST_FOUND)
+    switch (rc = host_find_bydns(h, ignore_target_hosts, whichrrs, NULL,
+       NULL, NULL,
+       &rblock->dnssec,                        /* domains for request/require */
+       &canonical_name, &removed))
       {
-      if (removed) setflag(addr, af_local_host_removed);
-      }
-    else if (rc == HOST_FIND_FAILED)
-      {
-      if (lookup_type == lk_default)
-        {
-        DEBUG(D_route|D_host_lookup)
-          debug_printf("DNS lookup failed: trying getipnodebyname\n");
-        rc = host_find_byname(h, ignore_target_hosts, HOST_FIND_QUALIFY_SINGLE,
-          &canonical_name, TRUE);
-        }
+      case HOST_FOUND:
+        if (removed) setflag(addr, af_local_host_removed);
+       break;
+      case HOST_FIND_FAILED:
+       if (lookup_type & LK_DEFAULT)
+         {
+         DEBUG(D_route|D_host_lookup)
+           debug_printf("DNS lookup failed: trying getipnodebyname\n");
+         rc = host_find_byname(h, ignore_target_hosts, HOST_FIND_QUALIFY_SINGLE,
+           &canonical_name, TRUE);
+         }
+       break;
       }
     }
 
   /* Temporary failure defers, unless pass_on_timeout is set */
 
+  if (rc == HOST_FIND_SECURITY)
+    {
+    addr->message = string_sprintf("host lookup for %s done insecurely" , h->name);
+    addr->basic_errno = ERRNO_DNSDEFER;
+    return DEFER;
+    }
   if (rc == HOST_FIND_AGAIN)
     {
     if (rblock->pass_on_timeout)
@@ -168,10 +193,11 @@ for (h = addr->host_list; h != NULL; h = next_h)
     if (hff_code == hff_pass) return PASS;
     if (hff_code == hff_decline) return DECLINE;
 
+    addr->basic_errno = ERRNO_UNKNOWNHOST;
     addr->message =
       string_sprintf("lookup of host \"%s\" failed in %s router%s",
         h->name, rblock->name,
-        host_find_failed_syntax? ": syntax error in name" : "");
+        f.host_find_failed_syntax? ": syntax error in name" : "");
 
     if (hff_code == hff_defer) return DEFER;
     if (hff_code == hff_fail) return FAIL;
@@ -180,7 +206,8 @@ for (h = addr->host_list; h != NULL; h = next_h)
     return DEFER;
     }
 
-  /* Deal with a port setting */
+  /* Deal with the settings that were previously cleared:
+  port, mx and sort_key. */
 
   if (port != PORT_NONE)
     {
@@ -188,13 +215,23 @@ for (h = addr->host_list; h != NULL; h = next_h)
     for (hh = h; hh != next_h; hh = hh->next) hh->port = port;
     }
 
+  if (mx != MX_NONE)
+    {
+    host_item *hh;
+    for (hh = h; hh != next_h; hh = hh->next)
+      {
+      hh->mx = mx;
+      hh->sort_key = sort_key;
+      }
+    }
+
   /* A local host gets chopped, with its successors, if there are previous
   hosts. Otherwise the self option is used. If it is set to "send", any
   subsequent hosts that are also the local host do NOT get chopped. */
 
   if (rc == HOST_FOUND_LOCAL && !self_send)
     {
-    if (prev != NULL)
+    if (prev)
       {
       DEBUG(D_route)
         {