From 92be34a4077672f592d47e2991b3530305517a28 Mon Sep 17 00:00:00 2001
From: Simon Kelley <simon@thekelleys.org.uk>
Date: Sat, 16 Jan 2016 18:39:54 +0000
Subject: [PATCH] Complete work to allow DNSSEC validation with private DNS
 servers.

---
 man/dnsmasq.8 |  5 ++++-
 src/forward.c | 34 +++++++++++++++++++++++++++++++---
 src/network.c | 33 +++++++++++++++++++--------------
 3 files changed, 54 insertions(+), 18 deletions(-)

diff --git a/man/dnsmasq.8 b/man/dnsmasq.8
index d51b10f..69acdae 100644
--- a/man/dnsmasq.8
+++ b/man/dnsmasq.8
@@ -405,7 +405,10 @@ xxx.internal.thekelleys.org.uk at 192.168.1.1 then giving  the flag
 .B -S /internal.thekelleys.org.uk/192.168.1.1 
 will send all queries for
 internal machines to that nameserver, everything else will go to the
-servers in /etc/resolv.conf. An empty domain specification,
+servers in /etc/resolv.conf. DNSSEC validation is turned off for such
+private nameservers, UNLESS a
+.B --trust-anchor
+is specified for the domain in question. An empty domain specification,
 .B // 
 has the special meaning of "unqualified names only" ie names without any
 dots in them. A non-standard port may be specified as 
diff --git a/src/forward.c b/src/forward.c
index 11c0d45..c48fd75 100644
--- a/src/forward.c
+++ b/src/forward.c
@@ -151,7 +151,7 @@ static unsigned int search_servers(time_t now, struct all_addr **addrpp, unsigne
 	    hostname_isequal(matchstart, serv->domain) &&
 	    (domainlen == 0 || namelen == domainlen || *(matchstart-1) == '.' ))
 	  {
-	    if (serv->flags & SERV_NO_REBIND)	
+	    if ((serv->flags & SERV_NO_REBIND) && norebind)	
 	      *norebind = 1;
 	    else
 	      {
@@ -644,7 +644,7 @@ static size_t process_reply(struct dns_header *header, time_t now, struct server
     return resize_packet(header, n, pheader, plen);
   
   /* Complain loudly if the upstream server is non-recursive. */
-  if (!(header->hb4 & HB4_RA) && RCODE(header) == NOERROR && ntohs(header->ancount) == 0 &&
+  if (!(header->hb4 & HB4_RA) && RCODE(header) == NOERROR &&
       server && !(server->flags & SERV_WARNED_RECURSIVE))
     {
       prettyprint_addr(&server->addr, daemon->namebuff);
@@ -923,12 +923,40 @@ void reply_query(int fd, int family, time_t now)
 		    status = STAT_ABANDONED;
 		  else
 		    {
-		      int fd;
+		      int fd, type;
 		      struct frec *next = new->next;
+		      char *domain;
+		      
 		      *new = *forward; /* copy everything, then overwrite */
 		      new->next = next;
 		      new->blocking_query = NULL;
+
+		      /* Find server to forward to. This will normally be the 
+			 same as for the original query, but may be another if
+			 servers for domains are involved. */		      
+		      if (search_servers(now, NULL, F_QUERY, daemon->keyname, &type, &domain, NULL) == 0)
+			{
+			   struct server *start = server;
+			   type &= ~SERV_DO_DNSSEC;
+			   
+			   while (1)
+			     {
+			       if (type == (start->flags & SERV_TYPE) &&
+				   (type != SERV_HAS_DOMAIN || hostname_isequal(domain, start->domain)) &&
+				   !(start->flags & (SERV_LITERAL_ADDRESS | SERV_LOOP)))
+				 {
+				   server = start;
+				   break;
+				 }
+			       
+			       if (!(start = start->next))
+				 start = daemon->servers;
+			       if (start == server)
+				 break;
+			     }
+			}
 		      new->sentto = server;
+
 		      new->rfd4 = NULL;
 #ifdef HAVE_IPV6
 		      new->rfd6 = NULL;
diff --git a/src/network.c b/src/network.c
index 303ae50..5451c6c 100644
--- a/src/network.c
+++ b/src/network.c
@@ -1442,20 +1442,25 @@ void check_servers(void)
       if (!(serv->flags & (SERV_LITERAL_ADDRESS | SERV_NO_ADDR | SERV_USE_RESOLV | SERV_NO_REBIND)))
 	{
 #ifdef HAVE_DNSSEC
-	  if (option_bool(OPT_DNSSEC_VALID) && (serv->flags & SERV_HAS_DOMAIN))
-	    {
-	      struct ds_config *ds;
-	      char *domain = serv->domain;
-
-	      /* .example.com is valid */
-	      while (*domain == '.')
-		domain++;
-	      
-	      for (ds = daemon->ds; ds; ds = ds->next)
-		if (ds->name[0] != 0 && hostname_isequal(domain, ds->name))
-		  break;
-
-	      if (!ds)
+	  if (option_bool(OPT_DNSSEC_VALID))
+	    { 
+	      if (serv->flags & SERV_HAS_DOMAIN)
+		{
+		  struct ds_config *ds;
+		  char *domain = serv->domain;
+		  
+		  /* .example.com is valid */
+		  while (*domain == '.')
+		    domain++;
+		  
+		  for (ds = daemon->ds; ds; ds = ds->next)
+		    if (ds->name[0] != 0 && hostname_isequal(domain, ds->name))
+		      break;
+		  
+		  if (!ds)
+		    serv->flags &= ~SERV_DO_DNSSEC;
+		}
+	      else if (serv->flags & SERV_FOR_NODOTS) 
 		serv->flags &= ~SERV_DO_DNSSEC;
 	    }
 #endif