--- embedaddon/dnsmasq/src/rrfilter.c	2016/11/02 09:57:01	1.1
+++ embedaddon/dnsmasq/src/rrfilter.c	2023/09/27 11:02:07	1.1.1.3
@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2016 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2022 Simon Kelley
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -14,7 +14,7 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-/* Code to safely remove RRs from an DNS answer */ 
+/* Code to safely remove RRs from a DNS answer */ 
 
 #include "dnsmasq.h"
 
@@ -156,10 +156,10 @@ static int check_rrs(unsigned char *p, struct dns_head
 }
 	
 
-/* mode is 0 to remove EDNS0, 1 to filter DNSSEC RRs */
+/* mode may be remove EDNS0 or DNSSEC RRs or remove A or AAAA from answer section. */
 size_t rrfilter(struct dns_header *header, size_t plen, int mode)
 {
-  static unsigned char **rrs;
+  static unsigned char **rrs = NULL;
   static int rr_sz = 0;
 
   unsigned char *p = (unsigned char *)(header+1);
@@ -173,7 +173,7 @@ size_t rrfilter(struct dns_header *header, size_t plen
   GETSHORT(qclass, p);
 
   /* First pass, find pointers to start and end of all the records we wish to elide:
-     records added for DNSSEC, unless explicity queried for */
+     records added for DNSSEC, unless explicitly queried for */
   for (rr_found = 0, chop_ns = 0, chop_an = 0, chop_ar = 0, i = 0; 
        i < ntohs(header->ancount) + ntohs(header->nscount) + ntohs(header->arcount);
        i++)
@@ -192,21 +192,38 @@ size_t rrfilter(struct dns_header *header, size_t plen
       if (!ADD_RDLEN(header, p, plen, rdlen))
 	return plen;
 
-      /* Don't remove the answer. */
-      if (i < ntohs(header->ancount) && type == qtype && class == qclass)
-	continue;
-      
-      if (mode == 0) /* EDNS */
+      if (mode == RRFILTER_EDNS0) /* EDNS */
 	{
 	  /* EDNS mode, remove T_OPT from additional section only */
 	  if (i < (ntohs(header->nscount) + ntohs(header->ancount)) || type != T_OPT)
 	    continue;
 	}
-      else if (type != T_NSEC && type != T_NSEC3 && type != T_RRSIG)
-	/* DNSSEC mode, remove SIGs and NSECs from all three sections. */
-	continue;
+      else if (mode == RRFILTER_DNSSEC)
+	{
+	  if (type != T_NSEC && type != T_NSEC3 && type != T_RRSIG)
+	    /* DNSSEC mode, remove SIGs and NSECs from all three sections. */
+	    continue;
+
+	  /* Don't remove the answer. */
+	  if (i < ntohs(header->ancount) && type == qtype && class == qclass)
+	    continue;
+	}
+      else
+	{
+	  /* Only looking at answer section now. */
+	  if (i >= ntohs(header->ancount))
+	    break;
+
+	  if (class != C_IN)
+	    continue;
+	  
+	  if (mode == RRFILTER_A && type != T_A)
+	    continue;
+
+	  if (mode == RRFILTER_AAAA && type != T_AAAA)
+	    continue;
+	}
       
-      
       if (!expand_workspace(&rrs, &rr_sz, rr_found + 1))
 	return plen; 
       
@@ -239,7 +256,15 @@ size_t rrfilter(struct dns_header *header, size_t plen
   if (!check_rrs(p, header, plen, 0, rrs, rr_found))
     return plen;
   
-  /* Third pass, elide records */
+  /* Third pass, actually fix up pointers in the records */
+  p = (unsigned char *)(header+1);
+  
+  check_name(&p, header, plen, 1, rrs, rr_found);
+  p += 4; /* qclass, qtype */
+  
+  check_rrs(p, header, plen, 1, rrs, rr_found);
+
+  /* Fourth pass, elide records */
   for (p = rrs[0], i = 1; i < rr_found; i += 2)
     {
       unsigned char *start = rrs[i];
@@ -254,14 +279,6 @@ size_t rrfilter(struct dns_header *header, size_t plen
   header->nscount = htons(ntohs(header->nscount) - chop_ns);
   header->arcount = htons(ntohs(header->arcount) - chop_ar);
 
-  /* Fourth pass, fix up pointers in the remaining records */
-  p = (unsigned char *)(header+1);
-  
-  check_name(&p, header, plen, 1, rrs, rr_found);
-  p += 4; /* qclass, qtype */
-  
-  check_rrs(p, header, plen, 1, rrs, rr_found);
-  
   return plen;
 }
 
@@ -270,7 +287,7 @@ u16 *rrfilter_desc(int type)
 {
   /* List of RRtypes which include domains in the data.
      0 -> domain
-     integer -> no of plain bytes
+     integer -> no. of plain bytes
      -1 -> end
 
      zero is not a valid RRtype, so the final entry is returned for
@@ -322,15 +339,11 @@ int expand_workspace(unsigned char ***wkspc, int *szp,
     return 0;
 
   new += 5;
-  
-  if (!(p = whine_malloc(new * sizeof(unsigned char *))))
-    return 0;  
-  
-  if (old != 0 && *wkspc)
-    {
-      memcpy(p, *wkspc, old * sizeof(unsigned char *));
-      free(*wkspc);
-    }
+
+  if (!(p = whine_realloc(*wkspc, new * sizeof(unsigned char *))))
+    return 0;
+
+  memset(p+old, 0, new-old);
   
   *wkspc = p;
   *szp = new;