Handle domain names with '.' or /000 within labels.

Only in DNSSEC mode, where we might need to validate or store
such names. In none-DNSSEC mode, simply don't cache these, as before.

CHANGELOG

@@ -68,11 +68,43 @@ version 2.73
 	    Fix broken DNSSEC validation of ECDSA signatures.
 
 	    Add --dnssec-timestamp option, which provides an automatic
-	    way to detect when the system time becomes valid after boot
-	    on systems without an RTC, whilst allowing DNS queries before the
-	    clock is valid so that NTP can run. Thanks to
-	    Kevin Darbyshire-Bryant for developing this idea.
-	
+	    way to detect when the system time becomes valid after 
+	    boot on systems without an RTC, whilst allowing DNS 
+	    queries before the clock is valid so that NTP can run. 
+	    Thanks to Kevin Darbyshire-Bryant for developing this idea.
+
+	    Add --tftp-no-fail option. Thanks to Stefan Tomanek for
+	    the patch.
+
+	    Fix crash caused by looking up servers.bind, CHAOS text 
+	    record, when more than about five --servers= lines are 
+	    in the dnsmasq config. This causes memory corruption 
+	    which causes a crash later. Thanks to Matt Coddington for 
+	    sterling work chasing this down.
+
+	    Fix crash on receipt of certain malformed DNS requests.
+	    Thanks to Nick Sampanis for spotting the problem.
+	    Note that this is could allow the dnsmasq process's
+	    memory to be read by an attacker under certain
+	    circumstances, so it has a CVE, CVE-2015-3294 
+
+            Fix crash in authoritative DNS code, if a .arpa zone 
+	    is declared as authoritative, and then a PTR query which
+	    is not to be treated as authoritative arrived. Normally, 
+	    directly declaring .arpa zone as authoritative is not 
+	    done, so this crash wouldn't be seen. Instead the 
+	    relevant .arpa zone should be specified as a subnet
+	    in the auth-zone declaration. Thanks to Johnny S. Lee
+	    for the bugreport and initial patch.
+
+	    Fix authoritative DNS code to correctly reply to NS 
+	    and SOA queries for .arpa zones for which we are 
+	    declared authoritative by means of a subnet in auth-zone.
+	    Previously we provided correct answers to PTR queries
+	    in such zones (including NS and SOA) but not direct
+	    NS and SOA queries. Thanks to Johnny S. Lee for 
+	    pointing out the problem.
+
 	
 version 2.72
             Add ra-advrouter mode, for RFC-3775 mobile IPv6 support.
@@ -117,7 +149,7 @@ version 2.72
             Fix problem with --local-service option on big-endian platforms
 	    Thanks to Richard Genoud for the patch.
 
-
+	
 version 2.71
             Subtle change to error handling to help DNSSEC validation 
 	    when servers fail to provide NODATA answers for 

contrib/wrt/dhcp_release.c

@@ -277,6 +277,11 @@ int main(int argc, char **argv)
       exit(1);
     }
   
+  if (inet_addr(argv[2]) == INADDR_NONE)
+    {
+      perror("invalid ip address");
+      exit(1);
+    }
   
   lease.s_addr = inet_addr(argv[2]);
   server = find_interface(lease, nl, if_nametoindex(argv[1]));

dnsmasq.conf.example

@@ -486,6 +486,9 @@
 # Set the root directory for files available via FTP.
 #tftp-root=/var/ftpd
 
+# Do not abort if the tftp-root is unavailable
+#tftp-no-fail
+
 # Make the TFTP server more secure: with this set, only files owned by
 # the user dnsmasq is running as will be send over the net.
 #tftp-secure

man/dnsmasq.8

@@ -1711,6 +1711,9 @@ Absolute paths (starting with /) are allowed, but they must be within
 the tftp-root. If the optional interface argument is given, the
 directory is only used for TFTP requests via that interface.
 .TP
+.B --tftp-no-fail
+Do not abort startup if specified tftp root directories are inaccessible.
+.TP
 .B --tftp-unique-root
 Add the IP address of the TFTP client as a path component on the end
 of the TFTP-root (in standard dotted-quad format). Only valid if a

src/auth.c

@@ -131,24 +131,27 @@ size_t answer_auth(struct dns_header *header, char *limit, size_t qlen, time_t n
 	  continue;
 	}
 
-      if (qtype == T_PTR)
+      if ((qtype == T_PTR || qtype == T_SOA || qtype == T_NS) &&
+	  (flag = in_arpa_name_2_addr(name, &addr)) &&
+	  !local_query)
 	{
-	  if (!(flag = in_arpa_name_2_addr(name, &addr)))
-	    continue;
-
-	  if (!local_query)
+	  for (zone = daemon->auth_zones; zone; zone = zone->next)
+	    if ((subnet = find_subnet(zone, flag, &addr)))
+	      break;
+	  
+	  if (!zone)
 	    {
-	      for (zone = daemon->auth_zones; zone; zone = zone->next)
-		if ((subnet = find_subnet(zone, flag, &addr)))
-		  break;
-	      
-	      if (!zone)
-		{
-		  auth = 0;
-		  continue;
-		}
+	      auth = 0;
+	      continue;
 	    }
+	  else if (qtype == T_SOA)
+	    soa = 1, found = 1;
+	  else if (qtype == T_NS)
+	    ns = 1, found = 1;
+	}
 
+      if (qtype == T_PTR && flag)
+	{
 	  intr = NULL;
 
 	  if (flag == F_IPV4)
@@ -186,7 +189,7 @@ size_t answer_auth(struct dns_header *header, char *limit, size_t qlen, time_t n
 	  
 	  if (intr)
 	    {
-	      if (in_zone(zone, intr->name, NULL))
+	      if (local_query || in_zone(zone, intr->name, NULL))
 		{	
 		  found = 1;
 		  log_query(flag | F_REVERSE | F_CONFIG, intr->name, &addr, NULL);
@@ -208,8 +211,11 @@ size_t answer_auth(struct dns_header *header, char *limit, size_t qlen, time_t n
 		    *p = 0; /* must be bare name */
 		  
 		  /* add  external domain */
-		  strcat(name, ".");
-		  strcat(name, zone->domain);
+		  if (zone)
+		    {
+		      strcat(name, ".");
+		      strcat(name, zone->domain);
+		    }
 		  log_query(flag | F_DHCP | F_REVERSE, name, &addr, record_source(crecp->uid));
 		  found = 1;
 		  if (add_resource_record(header, limit, &trunc, nameoffset, &ansp, 
@@ -217,7 +223,7 @@ size_t answer_auth(struct dns_header *header, char *limit, size_t qlen, time_t n
 					  T_PTR, C_IN, "d", name))
 		    anscount++;
 		}
-	      else if (crecp->flags & (F_DHCP | F_HOSTS) && in_zone(zone, name, NULL))
+	      else if (crecp->flags & (F_DHCP | F_HOSTS) && (local_query || in_zone(zone, name, NULL)))
 		{
 		  log_query(crecp->flags & ~F_FORWARD, name, &addr, record_source(crecp->uid));
 		  found = 1;
@@ -240,14 +246,20 @@ size_t answer_auth(struct dns_header *header, char *limit, size_t qlen, time_t n
 	}
       
     cname_restart:
-      for (zone = daemon->auth_zones; zone; zone = zone->next)
-	if (in_zone(zone, name, &cut))
-	  break;
-      
-      if (!zone)
+      if (found)
+	/* NS and SOA .arpa requests have set found above. */
+	cut = NULL;
+      else
 	{
-	  auth = 0;
-	  continue;
+	  for (zone = daemon->auth_zones; zone; zone = zone->next)
+	    if (in_zone(zone, name, &cut))
+	      break;
+	  
+	  if (!zone)
+	    {
+	      auth = 0;
+	      continue;
+	    }
 	}
 
       for (rec = daemon->mxnames; rec; rec = rec->next)

src/cache.c

@@ -1367,7 +1367,7 @@ int cache_make_stat(struct txt_record *t)
 		}
 	    port = prettyprint_addr(&serv->addr, daemon->addrbuff);
 	    lenp = p++; /* length */
-	    bytes_avail = (p - buff) + bufflen;
+	    bytes_avail = bufflen - (p - buff );
 	    bytes_needed = snprintf(p, bytes_avail, "%s#%d %u %u", daemon->addrbuff, port, queries, failed_queries);
 	    if (bytes_needed >= bytes_avail)
 	      {
@@ -1381,7 +1381,7 @@ int cache_make_stat(struct txt_record *t)
 		lenp = p - 1;
 		buff = new;
 		bufflen = newlen;
-		bytes_avail = (p - buff) + bufflen;
+		bytes_avail =  bufflen - (p - buff );
 		bytes_needed = snprintf(p, bytes_avail, "%s#%d %u %u", daemon->addrbuff, port, queries, failed_queries);
 	      }
 	    *lenp = bytes_needed;
@@ -1399,6 +1399,20 @@ int cache_make_stat(struct txt_record *t)
   return 1;
 }
 
+/* There can be names in the cache containing control chars, don't 
+   mess up logging or open security holes. */
+static char *sanitise(char *name)
+{
+  unsigned char *r;
+  if (name)
+    for (r = (unsigned char *)name; *r; r++)
+      if (!isprint((int)*r))
+	return "<name unprintable>";
+
+  return name;
+}
+
+
 void dump_cache(time_t now)
 {
   struct server *serv, *serv1;
@@ -1452,9 +1466,9 @@ void dump_cache(time_t now)
 	    *a = 0;
 	    if (strlen(n) == 0 && !(cache->flags & F_REVERSE))
 	      n = "<Root>";
-	    p += sprintf(p, "%-30.30s ", n);
+	    p += sprintf(p, "%-30.30s ", sanitise(n));
 	    if ((cache->flags & F_CNAME) && !is_outdated_cname_pointer(cache))
-	      a = cache_get_cname_target(cache);
+	      a = sanitise(cache_get_cname_target(cache));
 #ifdef HAVE_DNSSEC
 	    else if (cache->flags & F_DS)
 	      {
@@ -1587,6 +1601,8 @@ void log_query(unsigned int flags, char *name, struct all_addr *addr, char *arg)
   if (!option_bool(OPT_LOG))
     return;
 
+  name = sanitise(name);
+
   if (addr)
     {
       if (flags & F_KEYTAG)

src/dns-protocol.h

@@ -142,3 +142,7 @@ struct dns_header {
 
 #define ADD_RDLEN(header, pp, plen, len) \
   (!CHECK_LEN(header, pp, plen, len) ? 0 : (((pp) += (len)), 1))
+
+/* Escape character in our presentation format for names.
+   Cannot be '.' or /000 and must be !isprint() */
+#define NAME_ESCAPE 1

src/dnsmasq.c

@@ -58,6 +58,9 @@ int main (int argc, char **argv)
   struct dhcp_context *context;
   struct dhcp_relay *relay;
 #endif
+#ifdef HAVE_TFTP
+  int tftp_prefix_missing = 0;
+#endif
 
 #ifdef LOCALEDIR
   setlocale(LC_ALL, "");
@@ -99,8 +102,19 @@ int main (int argc, char **argv)
 #ifdef HAVE_DNSSEC
   if (option_bool(OPT_DNSSEC_VALID))
     {
-      daemon->keyname = safe_malloc(MAXDNAME);
-      daemon->workspacename = safe_malloc(MAXDNAME);
+      /* Note that both /000 and '.' are allowed within labels. These get
+	 represented in presentation format using NAME_ESCAPE as an escape
+	 character when in DNSSEC mode. 
+	 In theory, if all the characters in a name were /000 or
+	 '.' or NAME_ESCAPE then all would have to be escaped, so the 
+	 presentation format would be twice as long as the spec.
+
+	 daemon->namebuff was previously allocated by the option-reading
+	 code before we knew if we're in DNSSEC mode, so reallocate here. */
+      free(daemon->namebuff);
+      daemon->namebuff = safe_malloc(MAXDNAME * 2);
+      daemon->keyname = safe_malloc(MAXDNAME * 2);
+      daemon->workspacename = safe_malloc(MAXDNAME * 2);
     }
 #endif
 
@@ -342,7 +356,7 @@ int main (int argc, char **argv)
 #else
   die(_("DBus not available: set HAVE_DBUS in src/config.h"), NULL, EC_BADCONF);
 #endif
-  
+
   if (daemon->port != 0)
     pre_allocate_sfds();
 
@@ -636,7 +650,7 @@ int main (int argc, char **argv)
 #endif
 
 #ifdef HAVE_TFTP
-      if (option_bool(OPT_TFTP))
+  if (option_bool(OPT_TFTP))
     {
       DIR *dir;
       struct tftp_prefix *p;
@@ -645,20 +659,31 @@ int main (int argc, char **argv)
 	{
 	  if (!((dir = opendir(daemon->tftp_prefix))))
 	    {
-	      send_event(err_pipe[1], EVENT_TFTP_ERR, errno, daemon->tftp_prefix);
-	      _exit(0);
+	      tftp_prefix_missing = 1;
+	      if (!option_bool(OPT_TFTP_NO_FAIL))
+	        {
+	          send_event(err_pipe[1], EVENT_TFTP_ERR, errno, daemon->tftp_prefix);
+	          _exit(0);
+	        }
 	    }
-	  closedir(dir);
+	  else
+	    closedir(dir);
 	}
 
       for (p = daemon->if_prefix; p; p = p->next)
 	{
+	  p->missing = 0;
 	  if (!((dir = opendir(p->prefix))))
-	   {
-	     send_event(err_pipe[1], EVENT_TFTP_ERR, errno, p->prefix);
-	     _exit(0);
-	   } 
-	  closedir(dir);
+	    {
+	      p->missing = 1;
+	      if (!option_bool(OPT_TFTP_NO_FAIL))
+		{
+		  send_event(err_pipe[1], EVENT_TFTP_ERR, errno, p->prefix);
+		  _exit(0);
+		}
+	    }
+	  else
+	    closedir(dir);
 	}
     }
 #endif
@@ -773,6 +798,7 @@ int main (int argc, char **argv)
 #ifdef HAVE_TFTP
   if (option_bool(OPT_TFTP))
     {
+      struct tftp_prefix *p;
 #ifdef FD_SETSIZE
       if (FD_SETSIZE < (unsigned)max_fd)
 	max_fd = FD_SETSIZE;
@@ -782,7 +808,14 @@ int main (int argc, char **argv)
 		daemon->tftp_prefix ? _("root is ") : _("enabled"),
 		daemon->tftp_prefix ? daemon->tftp_prefix: "",
 		option_bool(OPT_TFTP_SECURE) ? _("secure mode") : "");
-      
+
+      if (tftp_prefix_missing)
+	my_syslog(MS_TFTP | LOG_WARNING, _("warning: %s inaccessible"), daemon->tftp_prefix);
+
+      for (p = daemon->if_prefix; p; p = p->next)
+	if (p->missing)
+	   my_syslog(MS_TFTP | LOG_WARNING, _("warning: TFTP directory %s inaccessible"), p->prefix);
+
       /* This is a guess, it assumes that for small limits, 
 	 disjoint files might be served, but for large limits, 
 	 a single file will be sent to may clients (the file only needs

src/dnsmasq.h

@@ -240,7 +240,8 @@ struct event_desc {
 #define OPT_LOCAL_SERVICE  49
 #define OPT_LOOP_DETECT    50
 #define OPT_EXTRALOG       51
-#define OPT_LAST           52
+#define OPT_TFTP_NO_FAIL   52
+#define OPT_LAST           53
 
 /* extra flags for my_syslog, we use a couple of facilities since they are known 
    not to occupy the same bits as priorities, no matter how syslog.h is set up. */
@@ -582,6 +583,7 @@ struct hostsfile {
 #define STAT_NO_NS             10
 #define STAT_NEED_DS_NEG       11
 #define STAT_CHASE_CNAME       12
+#define STAT_INSECURE_DS       13
 
 #define FREC_NOREBIND           1
 #define FREC_CHECKING_DISABLED  2
@@ -901,6 +903,7 @@ struct addr_list {
 struct tftp_prefix {
   char *interface;
   char *prefix;
+  int missing;
   struct tftp_prefix *next;
 };
 

src/dnssec.c

@@ -321,10 +321,18 @@ static int verify(struct blockdata *key_data, unsigned int key_len, unsigned cha
    thus generating names in canonical form.
    Calling to_wire followed by from_wire is almost an identity,
    except that the UC remains mapped to LC. 
+
+   Note that both /000 and '.' are allowed within labels. These get
+   represented in presentation format using NAME_ESCAPE as an escape
+   character. In theory, if all the characters in a name were /000 or
+   '.' or NAME_ESCAPE then all would have to be escaped, so the 
+   presentation format would be twice as long as the spec (1024). 
+   The buffers are all delcared as 2049 (allowing for the trailing zero) 
+   for this reason.
 */
 static int to_wire(char *name)
 {
-  unsigned char *l, *p, term;
+  unsigned char *l, *p, *q, term;
   int len;
 
   for (l = (unsigned char*)name; *l != 0; l = p)
@@ -332,7 +340,10 @@ static int to_wire(char *name)
       for (p = l; *p != '.' && *p != 0; p++)
 	if (*p >= 'A' && *p <= 'Z')
 	  *p = *p - 'A' + 'a';
-      
+	else if (*p == NAME_ESCAPE)
+	  for (q = p; *q; q++)
+	      *q = *(q+1);
+	       
       term = *p;
       
       if ((len = p - l) != 0)
@@ -351,13 +362,23 @@ static int to_wire(char *name)
 /* Note: no compression  allowed in input. */
 static void from_wire(char *name)
 {
-  unsigned char *l;
+  unsigned char *l, *p, *last;
   int len;
-
+  
+  for (last = (unsigned char *)name; *last != 0; last += *last+1);
+  
   for (l = (unsigned char *)name; *l != 0; l += len+1)
     {
       len = *l;
       memmove(l, l+1, len);
+      for (p = l; p < l + len; p++)
+	if (*p == '.' || *p == 0 || *p == NAME_ESCAPE)
+	  {
+	    memmove(p+1, p, 1 + last - p);
+	    len++;
+	    *p++ = NAME_ESCAPE;
+	  }
+	
       l[len] = '.';
     }
 
@@ -645,7 +666,7 @@ static void sort_rrset(struct dns_header *header, size_t plen, u16 *rr_desc, int
 	      if (left1 != 0)
 		memmove(buff1, buff1 + len1 - left1, left1);
 	      
-	      if ((len1 = get_rdata(header, plen, end1, buff1 + left1, MAXDNAME - left1, &p1, &dp1)) == 0)
+	      if ((len1 = get_rdata(header, plen, end1, buff1 + left1, (MAXDNAME * 2) - left1, &p1, &dp1)) == 0)
 		{
 		  quit = 1;
 		  len1 = end1 - p1;
@@ -656,7 +677,7 @@ static void sort_rrset(struct dns_header *header, size_t plen, u16 *rr_desc, int
 	      if (left2 != 0)
 		memmove(buff2, buff2 + len2 - left2, left2);
 	      
-	      if ((len2 = get_rdata(header, plen, end2, buff2 + left2, MAXDNAME - left2, &p2, &dp2)) == 0)
+	      if ((len2 = get_rdata(header, plen, end2, buff2 + left2, (MAXDNAME *2) - left2, &p2, &dp2)) == 0)
 		{
 		  quit = 1;
 		  len2 = end2 - p2;
@@ -902,10 +923,11 @@ static int validate_rrset(time_t now, struct dns_header *header, size_t plen, in
 	  
 	  end = p + rdlen;
 	  
-	  /* canonicalise rdata and calculate length of same, use name buffer as workspace */
+	  /* canonicalise rdata and calculate length of same, use name buffer as workspace.
+	     Note that name buffer is twice MAXDNAME long in DNSSEC mode. */
 	  cp = p;
 	  dp = rr_desc;
-	  for (len = 0; (seg = get_rdata(header, plen, end, name, MAXDNAME, &cp, &dp)) != 0; len += seg);
+	  for (len = 0; (seg = get_rdata(header, plen, end, name, MAXDNAME * 2, &cp, &dp)) != 0; len += seg);
 	  len += end - cp;
 	  len = htons(len);
 	  hash->update(ctx, 2, (unsigned char *)&len); 
@@ -913,7 +935,7 @@ static int validate_rrset(time_t now, struct dns_header *header, size_t plen, in
 	  /* Now canonicalise again and digest. */
 	  cp = p;
 	  dp = rr_desc;
-	  while ((seg = get_rdata(header, plen, end, name, MAXDNAME, &cp, &dp)))
+	  while ((seg = get_rdata(header, plen, end, name, MAXDNAME * 2, &cp, &dp)))
 	    hash->update(ctx, seg, (unsigned char *)name);
 	  if (cp != end)
 	    hash->update(ctx, end - cp, cp);
@@ -981,7 +1003,7 @@ int dnssec_validate_by_ds(time_t now, struct dns_header *header, size_t plen, ch
   
   /* If we've cached that DS provably doesn't exist, result must be INSECURE */
   if (crecp->flags & F_NEG)
-    return STAT_INSECURE;
+    return STAT_INSECURE_DS;
   
   /* NOTE, we need to find ONE DNSKEY which matches the DS */
   for (valid = 0, j = ntohs(header->ancount); j != 0 && !valid; j--) 
@@ -1177,7 +1199,7 @@ int dnssec_validate_by_ds(time_t now, struct dns_header *header, size_t plen, ch
    STAT_NO_DS       It's proved there's no DS here.
    STAT_NO_NS       It's proved there's no DS _or_ NS here.
    STAT_BOGUS       no DS in reply or not signed, fails validation, bad packet.
-   STAT_NEED_DNSKEY DNSKEY records to validate a DS not found, name in keyname
+   STAT_NEED_KEY    DNSKEY records to validate a DS not found, name in keyname
 */
 
 int dnssec_validate_ds(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int class)
@@ -1208,7 +1230,10 @@ int dnssec_validate_ds(time_t now, struct dns_header *header, size_t plen, char
   if (!(p = skip_section(p, ntohs(header->ancount), header, plen)))
     val = STAT_BOGUS;
   
-  if (val == STAT_BOGUS)
+  /* If the key needed to validate the DS is on the same domain as the DS, we'll
+     loop getting nowhere. Stop that now. This can happen of the DS answer comes
+     from the DS's zone, and not the parent zone. */
+  if (val == STAT_BOGUS ||  (val == STAT_NEED_KEY && hostname_isequal(name, keyname)))
     {
       log_query(F_NOEXTRA | F_UPSTREAM, name, NULL, "BOGUS DS");
       return STAT_BOGUS;
@@ -2032,7 +2057,8 @@ int dnssec_validate_reply(time_t now, struct dns_header *header, size_t plen, ch
   /* NXDOMAIN or NODATA reply, prove that (name, class1, type1) can't exist */
   /* First marshall the NSEC records, if we've not done it previously */
   if (!nsec_type && !(nsec_type = find_nsec_records(header, plen, &nsecs, &nsec_count, qclass)))
-    return STAT_BOGUS; /* No NSECs */
+    return STAT_NO_SIG; /* No NSECs, this is probably a dangling CNAME pointing into
+			   an unsigned zone. Return STAT_NO_SIG to cause this to be proved. */
    
   /* Get name of missing answer */
   if (!extract_name(header, plen, &qname, name, 1, 0))

src/forward.c

@@ -521,7 +521,8 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
 }
 
 static size_t process_reply(struct dns_header *header, time_t now, struct server *server, size_t n, int check_rebind, 
-			    int no_cache, int cache_secure, int ad_reqd, int do_bit, int added_pheader, int check_subnet, union mysockaddr *query_source)
+			    int no_cache, int cache_secure, int bogusanswer, int ad_reqd, int do_bit, int added_pheader, 
+			    int check_subnet, union mysockaddr *query_source)
 {
   unsigned char *pheader, *sizep;
   char **sets = 0;
@@ -529,7 +530,8 @@ static size_t process_reply(struct dns_header *header, time_t now, struct server
   size_t plen; 
 
   (void)ad_reqd;
-  (void) do_bit;
+  (void)do_bit;
+  (void)bogusanswer;
 
 #ifdef HAVE_IPSET
   if (daemon->ipsets && extract_request(header, n, daemon->namebuff, NULL))
@@ -634,7 +636,7 @@ static size_t process_reply(struct dns_header *header, time_t now, struct server
     }
   
 #ifdef HAVE_DNSSEC
-  if (no_cache && !(header->hb4 & HB4_CD)) 
+  if (bogusanswer && !(header->hb4 & HB4_CD)) 
     {
       if (!option_bool(OPT_DNSSEC_DEBUG))
 	{
@@ -663,6 +665,7 @@ static size_t process_reply(struct dns_header *header, time_t now, struct server
       header->ancount = htons(0);
       header->nscount = htons(0);
       header->arcount = htons(0);
+      header->hb3 &= ~HB3_TC;
     }
   
   /* the bogus-nxdomain stuff, doctor and NXDOMAIN->NODATA munging can all elide
@@ -785,7 +788,7 @@ void reply_query(int fd, int family, time_t now)
      everything is broken */
   if (forward->forwardall == 0 || --forward->forwardall == 1 || RCODE(header) != SERVFAIL)
     {
-      int check_rebind = 0, no_cache_dnssec = 0, cache_secure = 0;
+      int check_rebind = 0, no_cache_dnssec = 0, cache_secure = 0, bogusanswer = 0;
 
       if (option_bool(OPT_NO_REBIND))
 	check_rebind = !(forward->flags & FREC_NOREBIND);
@@ -818,7 +821,13 @@ void reply_query(int fd, int family, time_t now)
 	  else if (forward->flags & FREC_DS_QUERY)
 	    {
 	      status = dnssec_validate_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class);
-	      if (status == STAT_NO_DS || status == STAT_NO_NS)
+	      /* Provably no DS, everything below is insecure, even if signatures are offered */
+	      if (status == STAT_NO_DS)
+		/* We only cache sigs when we've validated a reply.
+		   Avoid caching a reply with sigs if there's a vaildated break in the 
+		   DS chain, so we don't return replies from cache missing sigs. */
+		status = STAT_INSECURE_DS;
+	      else if (status == STAT_NO_NS)
 		status = STAT_BOGUS;
 	    }
 	  else if (forward->flags & FREC_CHECK_NOSIGN)
@@ -958,8 +967,14 @@ void reply_query(int fd, int family, time_t now)
 		  else if (forward->flags & FREC_DS_QUERY)
 		    {
 		      status = dnssec_validate_ds(now, header, n, daemon->namebuff, daemon->keyname, forward->class);
-		      if (status == STAT_NO_DS || status == STAT_NO_NS)
-			status = STAT_BOGUS;
+		       /* Provably no DS, everything below is insecure, even if signatures are offered */
+		      if (status == STAT_NO_DS)
+			/* We only cache sigs when we've validated a reply.
+			   Avoid caching a reply with sigs if there's a vaildated break in the 
+			   DS chain, so we don't return replies from cache missing sigs. */
+			status = STAT_INSECURE_DS;
+		      else if (status == STAT_NO_NS)
+			status = STAT_BOGUS; 
 		    }
 		  else if (forward->flags & FREC_CHECK_NOSIGN)
 		    {
@@ -984,26 +999,44 @@ void reply_query(int fd, int family, time_t now)
 		}
 	    }
 	  
+	  no_cache_dnssec = 0;
+
+	  if (status == STAT_INSECURE_DS)
+	    {
+	      /* We only cache sigs when we've validated a reply.
+		 Avoid caching a reply with sigs if there's a vaildated break in the 
+		 DS chain, so we don't return replies from cache missing sigs. */
+	      status = STAT_INSECURE;
+	      no_cache_dnssec = 1;
+	    }
+	  
 	  if (status == STAT_TRUNCATED)
 	    header->hb3 |= HB3_TC;
 	  else
 	    {
-	      char *result;
+	      char *result, *domain = "result";
 	      
 	      if (forward->work_counter == 0)
-		result = "ABANDONED";
+		{
+		  result = "ABANDONED";
+		  status = STAT_BOGUS;
+		}
 	      else
 		result = (status == STAT_SECURE ? "SECURE" : (status == STAT_INSECURE ? "INSECURE" : "BOGUS"));
 	      
-	      log_query(F_KEYTAG | F_SECSTAT, "result", NULL, result);
+	      if (status == STAT_BOGUS && extract_request(header, n, daemon->namebuff, NULL))
+		domain = daemon->namebuff;
+
+	      log_query(F_KEYTAG | F_SECSTAT, domain, NULL, result);
 	    }
 	  
-	  no_cache_dnssec = 0;
-	  
 	  if (status == STAT_SECURE)
 	    cache_secure = 1;
 	  else if (status == STAT_BOGUS)
-	    no_cache_dnssec = 1;
+	    {
+	      no_cache_dnssec = 1;
+	      bogusanswer = 1;
+	    }
 	}
 #endif     
       
@@ -1013,7 +1046,7 @@ void reply_query(int fd, int family, time_t now)
       else
 	header->hb4 &= ~HB4_CD;
       
-      if ((nn = process_reply(header, now, server, (size_t)n, check_rebind, no_cache_dnssec, cache_secure,
+      if ((nn = process_reply(header, now, server, (size_t)n, check_rebind, no_cache_dnssec, cache_secure, bogusanswer, 
 			      forward->flags & FREC_AD_QUESTION, forward->flags & FREC_DO_QUESTION, 
 			      forward->flags & FREC_ADDED_PHEADER, forward->flags & FREC_HAS_SUBNET, &forward->source)))
 	{
@@ -1416,7 +1449,7 @@ static int do_check_sign(struct frec *forward, int status, time_t now, char *nam
     }
 }
 
-/* Move toward the root, until we find a signed non-existance of a DS, in which case
+/* Move down from the root, until we find a signed non-existance of a DS, in which case
    an unsigned answer is OK, or we find a signed DS, in which case there should be 
    a signature, and the answer is BOGUS */
 static int  tcp_check_for_unsigned_zone(time_t now, struct dns_header *header, size_t plen, int class, char *name, 
@@ -1566,8 +1599,13 @@ static int tcp_key_recurse(time_t now, int status, struct dns_header *header, si
   else if (status == STAT_NEED_DS || status == STAT_NEED_DS_NEG)
     {
       new_status = dnssec_validate_ds(now, header, n, name, keyname, class);
-      if (status == STAT_NEED_DS && (new_status == STAT_NO_DS || new_status == STAT_NO_NS))
-	new_status = STAT_BOGUS;
+      if (status == STAT_NEED_DS)
+	{
+	  if (new_status == STAT_NO_DS)
+	    new_status = STAT_INSECURE_DS;
+	  else if (new_status == STAT_NO_NS)
+	    new_status = STAT_BOGUS;
+	}
     }
   else if (status == STAT_CHASE_CNAME)
     new_status = dnssec_chase_cname(now, header, n, name, keyname);
@@ -1626,8 +1664,13 @@ static int tcp_key_recurse(time_t now, int status, struct dns_header *header, si
 	      else if (status == STAT_NEED_DS || status == STAT_NEED_DS_NEG)
 		{
 		  new_status = dnssec_validate_ds(now, header, n, name, keyname, class);
-		  if (status == STAT_NEED_DS  && (new_status == STAT_NO_DS || new_status == STAT_NO_NS))
-		    new_status = STAT_BOGUS; /* Validated no DS */
+		  if (status == STAT_NEED_DS)
+		    {
+		      if (new_status == STAT_NO_DS)
+			new_status = STAT_INSECURE_DS;
+		      else if (new_status == STAT_NO_NS)
+			new_status = STAT_BOGUS; /* Validated no DS */
+		    }
 		}
 	      else if (status == STAT_CHASE_CNAME)
 		new_status = dnssec_chase_cname(now, header, n, name, keyname);
@@ -1648,7 +1691,7 @@ static int tcp_key_recurse(time_t now, int status, struct dns_header *header, si
 		goto another_tcp_key;
 	    }
 	}
-
+      
       free(packet);
     }
   return new_status;
@@ -1669,7 +1712,7 @@ unsigned char *tcp_request(int confd, time_t now,
   int local_auth = 0;
 #endif
   int checking_disabled, ad_question, do_bit, added_pheader = 0;
-  int check_subnet, no_cache_dnssec = 0, cache_secure = 0;
+  int check_subnet, no_cache_dnssec = 0, cache_secure = 0, bogusanswer = 0;
   size_t m;
   unsigned short qtype;
   unsigned int gotname;
@@ -1935,18 +1978,35 @@ unsigned char *tcp_request(int confd, time_t now,
 			{
 			  int keycount = DNSSEC_WORK; /* Limit to number of DNSSEC questions, to catch loops and avoid filling cache. */
 			  int status = tcp_key_recurse(now, STAT_TRUNCATED, header, m, 0, daemon->namebuff, daemon->keyname, last_server, &keycount);
-			  char *result;
+			  char *result, *domain = "result";
 
+			  if (status == STAT_INSECURE_DS)
+			    {
+			      /* We only cache sigs when we've validated a reply.
+				 Avoid caching a reply with sigs if there's a vaildated break in the 
+				 DS chain, so we don't return replies from cache missing sigs. */
+			      status = STAT_INSECURE;
+			      no_cache_dnssec = 1;
+			    }
+			  
 			  if (keycount == 0)
-			    result = "ABANDONED";
+			    {
+			      result = "ABANDONED";
+			      status = STAT_BOGUS;
+			    }
 			  else
 			    result = (status == STAT_SECURE ? "SECURE" : (status == STAT_INSECURE ? "INSECURE" : "BOGUS"));
-			  
-			  log_query(F_KEYTAG | F_SECSTAT, "result", NULL, result);
+			   if (status == STAT_BOGUS && extract_request(header, m, daemon->namebuff, NULL))
+			     domain = daemon->namebuff;
+
+			  log_query(F_KEYTAG | F_SECSTAT, domain, NULL, result);
 			  
 			  if (status == STAT_BOGUS)
-			    no_cache_dnssec = 1;
-			  
+			    {
+			      no_cache_dnssec = 1;
+			      bogusanswer = 1;
+			    }
+
 			  if (status == STAT_SECURE)
 			    cache_secure = 1;
 			}
@@ -1980,7 +2040,7 @@ unsigned char *tcp_request(int confd, time_t now,
 #endif
 
 		      m = process_reply(header, now, last_server, (unsigned int)m, 
-					option_bool(OPT_NO_REBIND) && !norebind, no_cache_dnssec,
+					option_bool(OPT_NO_REBIND) && !norebind, no_cache_dnssec, bogusanswer,
 					cache_secure, ad_question, do_bit, added_pheader, check_subnet, &peer_addr); 
 		      
 		      break;

src/option.c

@@ -153,6 +153,7 @@ struct myoption {
 #define LOPT_DHOPT_INOTIFY 341
 #define LOPT_HOST_INOTIFY  342
 #define LOPT_DNSSEC_STAMP  343
+#define LOPT_TFTP_NO_FAIL  344
 
 #ifdef HAVE_GETOPT_LONG
 static const struct option opts[] =  
@@ -235,6 +236,7 @@ static const struct myoption opts[] =
     { "dhcp-ignore-names", 2, 0, LOPT_NO_NAMES },
     { "enable-tftp", 2, 0, LOPT_TFTP },
     { "tftp-secure", 0, 0, LOPT_SECURE },
+    { "tftp-no-fail", 0, 0, LOPT_TFTP_NO_FAIL },
     { "tftp-unique-root", 0, 0, LOPT_APREF },
     { "tftp-root", 1, 0, LOPT_PREFIX },
     { "tftp-max", 1, 0, LOPT_TFTP_MAX },
@@ -419,6 +421,7 @@ static struct {
   { LOPT_PREFIX, ARG_DUP, "<dir>[,<iface>]", gettext_noop("Export files by TFTP only from the specified subtree."), NULL },
   { LOPT_APREF, OPT_TFTP_APREF, NULL, gettext_noop("Add client IP address to tftp-root."), NULL },
   { LOPT_SECURE, OPT_TFTP_SECURE, NULL, gettext_noop("Allow access only to files owned by the user running dnsmasq."), NULL },
+  { LOPT_TFTP_NO_FAIL, OPT_TFTP_NO_FAIL, NULL, gettext_noop("Do not terminate the service if TFTP directories are inaccessible."), NULL },
   { LOPT_TFTP_MAX, ARG_ONE, "<integer>", gettext_noop("Maximum number of conncurrent TFTP transfers (defaults to %s)."), "#" },
   { LOPT_NOBLOCK, OPT_TFTP_NOBLOCK, NULL, gettext_noop("Disable the TFTP blocksize extension."), NULL },
   { LOPT_TFTP_LC, OPT_TFTP_LC, NULL, gettext_noop("Convert TFTP filenames to lowercase"), NULL },

src/rfc1035.c

@@ -128,8 +128,17 @@ int extract_name(struct dns_header *header, size_t plen, unsigned char **pp,
 	    if (isExtract)
 	      {
 		unsigned char c = *p;
-		if (isascii(c) && !iscntrl(c) && c != '.')
-		  *cp++ = *p;
+#ifdef HAVE_DNSSEC
+		if (option_bool(OPT_DNSSEC_VALID))
+		  {
+		    if (c == 0 || c == '.' || c == NAME_ESCAPE)
+		      *cp++ = NAME_ESCAPE;
+		    *cp++ = c;
+		  }
+		else
+#endif
+		if (c != 0 && c != '.')
+		  *cp++ = c;
 		else
 		  return 0;
 	      }
@@ -144,9 +153,14 @@ int extract_name(struct dns_header *header, size_t plen, unsigned char **pp,
 		    cp++;
 		    if (c1 >= 'A' && c1 <= 'Z')
 		      c1 += 'a' - 'A';
+#ifdef HAVE_DNSSEC
+		    if (option_bool(OPT_DNSSEC_VALID) && c1 == NAME_ESCAPE)
+		      c1 = *cp++;
+#endif
+		    
 		    if (c2 >= 'A' && c2 <= 'Z')
 		      c2 += 'a' - 'A';
-		    
+		     
 		    if (c1 != c2)
 		      retvalue =  2;
 		  }
@@ -1198,7 +1212,10 @@ unsigned int extract_request(struct dns_header *header, size_t qlen, char *name,
 size_t setup_reply(struct dns_header *header, size_t qlen,
 		struct all_addr *addrp, unsigned int flags, unsigned long ttl)
 {
-  unsigned char *p = skip_questions(header, qlen);
+  unsigned char *p;
+
+  if (!(p = skip_questions(header, qlen)))
+    return 0;
   
   /* clear authoritative and truncated flags, set QR flag */
   header->hb3 = (header->hb3 & ~(HB3_AA | HB3_TC)) | HB3_QR;
@@ -1214,7 +1231,7 @@ size_t setup_reply(struct dns_header *header, size_t qlen,
     SET_RCODE(header, NOERROR); /* empty domain */
   else if (flags == F_NXDOMAIN)
     SET_RCODE(header, NXDOMAIN);
-  else if (p && flags == F_IPV4)
+  else if (flags == F_IPV4)
     { /* we know the address */
       SET_RCODE(header, NOERROR);
       header->ancount = htons(1);
@@ -1222,7 +1239,7 @@ size_t setup_reply(struct dns_header *header, size_t qlen,
       add_resource_record(header, NULL, NULL, sizeof(struct dns_header), &p, ttl, NULL, T_A, C_IN, "4", addrp);
     }
 #ifdef HAVE_IPV6
-  else if (p && flags == F_IPV6)
+  else if (flags == F_IPV6)
     {
       SET_RCODE(header, NOERROR);
       header->ancount = htons(1);

src/rfc3315.c

@@ -824,25 +824,21 @@ static int dhcp6_no_relay(struct state *state, int msg_type, void *inbuff, size_
 	  }
 	else
 	  { 
-	    /* Windows 8 always requests an address even if the Managed bit
-	       in RA is 0 and it keeps retrying if it receives a reply
-	       stating that no addresses are available. We solve this 
-	       by not replying at all if we're not configured to give any 
-	       addresses by DHCPv6. RFC 3315 17.2.1. appears to allow this. */
-	    
-	    for (c = state->context; c; c = c->current)
-	      if (!(c->flags & CONTEXT_RA_STATELESS))
-		break;
-	    
-	    if (!c)
-	      return 0;
-	    
 	    /* no address, return error */
 	    o1 = new_opt6(OPTION6_STATUS_CODE);
 	    put_opt6_short(DHCP6NOADDRS);
 	    put_opt6_string(_("no addresses available"));
 	    end_opt6(o1);
-	    log6_packet(state, state->lease_allocate ? "DHCPREPLY" : "DHCPADVERTISE", NULL, _("no addresses available"));
+
+	    /* Some clients will ask repeatedly when we're not giving
+	       out addresses because we're in stateless mode. Avoid spamming
+	       the log in that case. */
+	    for (c = state->context; c; c = c->current)
+	      if (!(c->flags & CONTEXT_RA_STATELESS))
+		{
+		  log6_packet(state, state->lease_allocate ? "DHCPREPLY" : "DHCPADVERTISE", NULL, _("no addresses available"));
+		  break;
+		}
 	  }
 
 	break;

src/tftp.c

@@ -236,7 +236,7 @@ void tftp_request(struct listener *listen, time_t now)
       if (ioctl(listen->tftpfd, SIOCGIFMTU, &ifr) != -1)
 	mtu = ifr.ifr_mtu;      
     }
-  
+
   if (name)
     {
       /* check for per-interface prefix */ 

src/util.c

@@ -226,7 +226,14 @@ unsigned char *do_rfc1035_name(unsigned char *p, char *sval)
     {
       unsigned char *cp = p++;
       for (j = 0; *sval && (*sval != '.'); sval++, j++)
-	*p++ = *sval;
+	{
+#ifdef HAVE_DNSSEC
+	  if (option_bool(OPT_DNSSEC_VALID) && *sval == NAME_ESCAPE)
+	    *p++ = *(++sval);
+	  else
+#endif		
+	    *p++ = *sval;
+	}
       *cp  = j;
       if (*sval)
 	sval++;