Fix buffer overflow introduced in 2.73rc6.

Fix off-by-one in code which checks for over-long domain names
in received DNS packets. This enables buffer overflow attacks
which can certainly crash dnsmasq and may allow for arbitrary
code execution. The problem was introduced in commit b8f16556d,
release 2.73rc6, so has not escaped into any stable release.
Note that the off-by-one was in the label length determination,
so the buffer can be overflowed by as many bytes as there are
labels in the name - ie, many.

Thanks to Ron Bowes, who used lcmatuf's afl-fuzz tool to find
the problem.

CHANGELOG

@@ -68,11 +68,59 @@ 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.
+
+	    Fix logging of DHCPREPLY which should be suppressed 
+	    by quiet-dhcp6. Thanks to J. Pablo Abonia for 
+	    spotting the problem.
+
+	    Try and handle net connections with broken fragmentation 
+	    that lose large UDP packets. If a server times out, 
+            reduce the maximum UDP packet size field in the EDNS0
+	    header to 1280 bytes. If it then answers, make that
+	    change permanent.
+
+	    Check IPv4-mapped IPv6 addresses when --stop-rebind
+	    is active. Thanks to Jordan Milne for spotting this.
+
+	    Allow DHCPv4 options T1 and T2 to be set using --dhcp-option.
+	    Thanks to Kevin Benton for patches and work on this.
+
 	
 version 2.72
             Add ra-advrouter mode, for RFC-3775 mobile IPv6 support.
@@ -117,7 +165,7 @@ 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 

bld/get-version

@@ -11,8 +11,9 @@
 # If there is more than one v[0-9].* tag, sort them and use the
 # first. This favours, eg v2.63 over 2.63rc6.
 
-if which git >/dev/null 2>&1 && [ -d $1/.git ]; then
-     cd $1; git describe | sed 's/^v//'
+if which git >/dev/null 2>&1 && \
+    ([ -d $1/.git ] || grep '^gitdir:' $1/.git >/dev/null 2>&1); then 
+    cd $1; git describe | sed 's/^v//'
 elif grep '\$Format:%d\$' $1/VERSION >/dev/null 2>&1; then
 # unsubstituted VERSION, but no git available.
     echo UNKNOWN

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]));

debian/changelog

@@ -5,6 +5,7 @@ dnsmasq (2.73-1) unstable; urgency=low
      addresses. (closes: #771557)
    * Add newline at the end of example config file. (LP: #1416895)
    * Make Debian package build reproducible. (closes: #777323)
+   * Add Requires=network.target to systemd unit.
 
  -- Simon Kelley <simon@thekelleys.org.uk>  Wed, 11 Feb 2015 21:59:42 +0000
 

debian/systemd.service

@@ -1,5 +1,6 @@
 [Unit]
 Description=dnsmasq - A lightweight DHCP and caching DNS server
+Requires=network.target
 
 [Service]
 Type=forking

dnsmasq.conf.example

@@ -345,6 +345,14 @@
 # Ask client to poll for option changes every six hours. (RFC4242)
 #dhcp-option=option6:information-refresh-time,6h
 
+# Set option 58 client renewal time (T1). Defaults to half of the
+# lease time if not specified. (RFC2132)
+#dhcp-option=option:T1:1m
+
+# Set option 59 rebinding time (T2). Defaults to 7/8 of the
+# lease time if not specified. (RFC2132)
+#dhcp-option=option:T2:2m
+
 # Set the NTP time server address to be the same machine as
 # is running dnsmasq
 #dhcp-option=42,0.0.0.0
@@ -486,6 +494,9 @@
 # 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

doc.html

@@ -74,7 +74,9 @@ for details.
 There is a dnsmasq mailing list at <A
 HREF="http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss">
 http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss</A> which should be the
-first location for queries, bugreports, suggestions etc.
+first location for queries, bugreports, suggestions etc. The list is mirrored, with a
+search facility, at <A HREF="https://www.mail-archive.com/dnsmasq-discuss@lists.thekelleys.org.uk/">
+https://www.mail-archive.com/dnsmasq-discuss@lists.thekelleys.org.uk/</A>.
 You can contact me at <A
 HREF="mailto:simon@thekelleys.org.uk">simon@thekelleys.org.uk</A>.
 

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/config.h

@@ -19,6 +19,7 @@
 #define CHILD_LIFETIME 150 /* secs 'till terminated (RFC1035 suggests > 120s) */
 #define TCP_MAX_QUERIES 100 /* Maximum number of queries per incoming TCP connection */
 #define EDNS_PKTSZ 4096 /* default max EDNS.0 UDP packet from RFC5625 */
+#define SAFE_PKTSZ 1280 /* "go anywhere" UDP packet size */
 #define KEYBLOCK_LEN 40 /* choose to mininise fragmentation when storing DNSSEC keys */
 #define DNSSEC_WORK 50 /* Max number of queries to validate one question */
 #define TIMEOUT 10 /* drop UDP queries after TIMEOUT seconds */

src/dhcp-common.c

@@ -545,8 +545,8 @@ static const struct opttab_t {
   { "parameter-request", 55, OT_INTERNAL },
   { "message", 56, OT_INTERNAL },
   { "max-message-size", 57, OT_INTERNAL },
-  { "T1", 58, OT_INTERNAL | OT_TIME},
-  { "T2", 59, OT_INTERNAL | OT_TIME},
+  { "T1", 58, OT_TIME},
+  { "T2", 59, OT_TIME},
   { "vendor-class", 60, 0 },
   { "client-id", 61, OT_INTERNAL },
   { "nis+-domain", 64, OT_NAME },

src/dns-protocol.h

@@ -142,3 +142,11 @@ 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().
+   Note that escaped chars are stored as
+   <NAME_ESCAPE> <orig-char+1>
+   to ensure that the escaped form of /000 doesn't include /000
+*/
+#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. */
@@ -503,7 +504,7 @@ struct server {
   char interface[IF_NAMESIZE+1];
   struct serverfd *sfd; 
   char *domain; /* set if this server only handles a domain. */ 
-  int flags, tcpfd;
+  int flags, tcpfd, edns_pktsz;
   unsigned int queries, failed_queries;
 #ifdef HAVE_LOOP
   u32 uid;
@@ -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
@@ -592,6 +594,7 @@ struct hostsfile {
 #define FREC_DO_QUESTION       64
 #define FREC_ADDED_PHEADER    128
 #define FREC_CHECK_NOSIGN     256
+#define FREC_TEST_PKTSZ       512
 
 #ifdef HAVE_DNSSEC
 #define HASH_SIZE 20 /* SHA-1 digest size */
@@ -901,6 +904,7 @@ struct addr_list {
 struct tftp_prefix {
   char *interface;
   char *prefix;
+  int missing;
   struct tftp_prefix *next;
 };
 
@@ -1145,7 +1149,7 @@ int in_zone(struct auth_zone *zone, char *name, char **cut);
 #endif
 
 /* dnssec.c */
-size_t dnssec_generate_query(struct dns_header *header, char *end, char *name, int class, int type, union mysockaddr *addr);
+size_t dnssec_generate_query(struct dns_header *header, char *end, char *name, int class, int type, union mysockaddr *addr, int edns_pktsz);
 int dnssec_validate_by_ds(time_t now, struct dns_header *header, size_t n, char *name, char *keyname, int class);
 int dnssec_validate_ds(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int class);
 int dnssec_validate_reply(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int *class, int *neganswer, int *nons);
@@ -1301,9 +1305,10 @@ void lease_update_slaac(time_t now);
 void lease_set_iaid(struct dhcp_lease *lease, int iaid);
 void lease_make_duid(time_t now);
 #endif
-void lease_set_hwaddr(struct dhcp_lease *lease, unsigned char *hwaddr,
-		      unsigned char *clid, int hw_len, int hw_type, int clid_len, time_t now, int force);
-void lease_set_hostname(struct dhcp_lease *lease, char *name, int auth, char *domain, char *config_domain);
+void lease_set_hwaddr(struct dhcp_lease *lease, const unsigned char *hwaddr,
+		      const unsigned char *clid, int hw_len, int hw_type,
+		      int clid_len, time_t now, int force);
+void lease_set_hostname(struct dhcp_lease *lease, const char *name, int auth, char *domain, char *config_domain);
 void lease_set_expires(struct dhcp_lease *lease, unsigned int len, time_t now);
 void lease_set_interface(struct dhcp_lease *lease, int interface, time_t now);
 struct dhcp_lease *lease_find_by_client(unsigned char *hwaddr, int hw_len, int hw_type,  

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 +340,12 @@ 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);
+	    (*p)--;
+	  }
       term = *p;
       
       if ((len = p - l) != 0)
@@ -351,13 +364,24 @@ 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; 
+	    (*p)++;
+	  }
+	
       l[len] = '.';
     }
 
@@ -645,7 +669,7 @@ 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 +680,7 @@ 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 +926,11 @@ 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 +938,7 @@ 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 +1006,7 @@ 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 +1202,7 @@ 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 +1233,10 @@ 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 +2060,8 @@ 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))
@@ -2133,10 +2162,12 @@ int dnskey_keytag(int alg, int flags, unsigned char *key, int keylen)
     }
 }
 
-size_t dnssec_generate_query(struct dns_header *header, char *end, char *name, int class, int type, union mysockaddr *addr)
+size_t dnssec_generate_query(struct dns_header *header, char *end, char *name, int class, 
+			     int type, union mysockaddr *addr, int edns_pktsz)
 {
   unsigned char *p;
   char *types = querystr("dnssec-query", type);
+  size_t ret;
 
   if (addr->sa.sa_family == AF_INET) 
     log_query(F_NOEXTRA | F_DNSSEC | F_IPV4, name, (struct all_addr *)&addr->in.sin_addr, types);
@@ -2165,7 +2196,12 @@ size_t dnssec_generate_query(struct dns_header *header, char *end, char *name, i
   PUTSHORT(type, p);
   PUTSHORT(class, p);
 
-  return add_do_bit(header, p - (unsigned char *)header, end);
+  ret = add_do_bit(header, p - (unsigned char *)header, end);
+
+  if (find_pseudoheader(header, ret, NULL, &p, NULL))
+    PUTSHORT(edns_pktsz, p);
+
+  return ret;
 }
 
 /* Go through a domain name, find "pointers" and fix them up based on how many bytes

src/forward.c

@@ -253,6 +253,7 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
   void *hash = &crc;
 #endif
  unsigned int gotname = extract_request(header, plen, daemon->namebuff, NULL);
+ unsigned char *pheader;
 
  (void)do_bit;
 
@@ -261,19 +262,32 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
     forward = NULL;
   else if (forward || (hash && (forward = lookup_frec_by_sender(ntohs(header->id), udpaddr, hash))))
     {
+      /* If we didn't get an answer advertising a maximal packet in EDNS,
+	 fall back to 1280, which should work everywhere on IPv6.
+	 If that generates an answer, it will become the new default
+	 for this server */
+      forward->flags |= FREC_TEST_PKTSZ;
+      
 #ifdef HAVE_DNSSEC
       /* If we've already got an answer to this query, but we're awaiting keys for validation,
 	 there's no point retrying the query, retry the key query instead...... */
       if (forward->blocking_query)
 	{
 	  int fd;
-
+	  
+	  forward->flags &= ~FREC_TEST_PKTSZ;
+	  
 	  while (forward->blocking_query)
 	    forward = forward->blocking_query;
+	   
+	  forward->flags |= FREC_TEST_PKTSZ;
 	  
 	  blockdata_retrieve(forward->stash, forward->stash_len, (void *)header);
 	  plen = forward->stash_len;
 	  
+	  if (find_pseudoheader(header, plen, NULL, &pheader, NULL))
+	    PUTSHORT((forward->flags & FREC_TEST_PKTSZ) ? SAFE_PKTSZ : forward->sentto->edns_pktsz, pheader);
+
 	  if (forward->sentto->addr.sa.sa_family == AF_INET) 
 	    log_query(F_NOEXTRA | F_DNSSEC | F_IPV4, "retry", (struct all_addr *)&forward->sentto->addr.in.sin_addr, "dnssec");
 #ifdef HAVE_IPV6
@@ -417,7 +431,7 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
 	  plen = new_plen;
 	}
 #endif
-
+      
       while (1)
 	{ 
 	  /* only send to servers dealing with our domain.
@@ -464,6 +478,9 @@ static int forward_query(int udpfd, union mysockaddr *udpaddr,
 		    }
 #endif
 		}
+
+	      if (find_pseudoheader(header, plen, NULL, &pheader, NULL))
+		PUTSHORT((forward->flags & FREC_TEST_PKTSZ) ? SAFE_PKTSZ : start->edns_pktsz, pheader);
 	      
 	      if (retry_send(sendto(fd, (char *)header, plen, 0,
 				    &start->addr.sa,
@@ -521,7 +538,8 @@ 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 +547,8 @@ 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 +653,7 @@ 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 +682,7 @@ 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
@@ -757,7 +777,6 @@ void reply_query(int fd, int family, time_t now)
     }   
    
   server = forward->sentto;
-  
   if ((forward->sentto->flags & SERV_TYPE) == 0)
     {
       if (RCODE(header) == REFUSED)
@@ -778,14 +797,21 @@ void reply_query(int fd, int family, time_t now)
       if (!option_bool(OPT_ALL_SERVERS))
 	daemon->last_server = server;
     }
-
+ 
+  /* We tried resending to this server with a smaller maximum size and got an answer.
+     Make that permanent. To avoid reduxing the packet size for an single dropped packet,
+     only do this when we get a truncated answer, or one larger than the safe size. */
+  if (server && (forward->flags & FREC_TEST_PKTSZ) && 
+      ((header->hb3 & HB3_TC) || n >= SAFE_PKTSZ))
+    server->edns_pktsz = SAFE_PKTSZ;
+  
   /* If the answer is an error, keep the forward record in place in case
      we get a good reply from another server. Kill it when we've
      had replies from all to avoid filling the forwarding table when
      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 +844,13 @@ 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)
@@ -881,7 +913,7 @@ void reply_query(int fd, int family, time_t now)
 		    {
 		      new->flags |= FREC_DNSKEY_QUERY; 
 		      nn = dnssec_generate_query(header, ((char *) header) + daemon->packet_buff_sz,
-						 daemon->keyname, forward->class, T_DNSKEY, &server->addr);
+						 daemon->keyname, forward->class, T_DNSKEY, &server->addr, server->edns_pktsz);
 		    }
 		  else 
 		    {
@@ -890,7 +922,7 @@ void reply_query(int fd, int family, time_t now)
 		      else
 			new->flags |= FREC_DS_QUERY;
 		      nn = dnssec_generate_query(header,((char *) header) + daemon->packet_buff_sz,
-						 daemon->keyname, forward->class, T_DS, &server->addr);
+						 daemon->keyname, forward->class, T_DS, &server->addr, server->edns_pktsz);
 		    }
 		  if ((hash = hash_questions(header, nn, daemon->namebuff)))
 		    memcpy(new->hash, hash, HASH_SIZE);
@@ -958,8 +990,14 @@ 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 +1022,44 @@ 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 +1069,7 @@ 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 +1472,7 @@ 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, 
@@ -1493,7 +1549,7 @@ static int  tcp_check_for_unsigned_zone(time_t now, struct dns_header *header, s
       
       /* Can't find it in the cache, have to send a query */
 
-      m = dnssec_generate_query(header, ((char *) header) + 65536, name_start, class, T_DS, &server->addr);
+      m = dnssec_generate_query(header, ((char *) header) + 65536, name_start, class, T_DS, &server->addr, server->edns_pktsz);
       
       *length = htons(m);
       
@@ -1566,8 +1622,13 @@ 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);
@@ -1600,7 +1661,7 @@ static int tcp_key_recurse(time_t now, int status, struct dns_header *header, si
 
     another_tcp_key:
       m = dnssec_generate_query(new_header, ((char *) new_header) + 65536, keyname, class, 
-				new_status == STAT_NEED_KEY ? T_DNSKEY : T_DS, &server->addr);
+				new_status == STAT_NEED_KEY ? T_DNSKEY : T_DS, &server->addr, server->edns_pktsz);
       
       *length = htons(m);
       
@@ -1626,8 +1687,13 @@ 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 +1714,7 @@ 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 +1735,7 @@ 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 +2001,36 @@ 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;
 			}
@@ -1980,8 +2064,8 @@ 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,
-					cache_secure, ad_question, do_bit, added_pheader, check_subnet, &peer_addr); 
+					option_bool(OPT_NO_REBIND) && !norebind, no_cache_dnssec, cache_secure, bogusanswer,
+					ad_question, do_bit, added_pheader, check_subnet, &peer_addr); 
 		      
 		      break;
 		    }

src/lease.c

@@ -813,9 +813,9 @@ void lease_set_iaid(struct dhcp_lease *lease, int iaid)
 }
 #endif
 
-void lease_set_hwaddr(struct dhcp_lease *lease, unsigned char *hwaddr,
-		      unsigned char *clid, int hw_len, int hw_type, int clid_len, 
-		      time_t now, int force)
+void lease_set_hwaddr(struct dhcp_lease *lease, const unsigned char *hwaddr,
+		      const unsigned char *clid, int hw_len, int hw_type,
+		      int clid_len, time_t now, int force)
 {
 #ifdef HAVE_DHCP6
   int change = force;
@@ -897,7 +897,7 @@ static void kill_name(struct dhcp_lease *lease)
   lease->hostname = lease->fqdn = NULL;
 }
 
-void lease_set_hostname(struct dhcp_lease *lease, char *name, int auth, char *domain, char *config_domain)
+void lease_set_hostname(struct dhcp_lease *lease, const char *name, int auth, char *domain, char *config_domain)
 {
   struct dhcp_lease *lease_tmp;
   char *new_name = NULL, *new_fqdn = NULL;

src/network.c

@@ -1396,6 +1396,7 @@ void add_update_server(int flags,
       serv->domain = domain_str;
       serv->next = next;
       serv->queries = serv->failed_queries = 0;
+      serv->edns_pktsz = daemon->edns_pktsz;
 #ifdef HAVE_LOOP
       serv->uid = rand32();
 #endif      

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 },
@@ -4495,15 +4498,19 @@ void read_opts(int argc, char **argv, char *compile_opts)
     {
       struct server *tmp;
       for (tmp = daemon->servers; tmp; tmp = tmp->next)
-	if (!(tmp->flags & SERV_HAS_SOURCE))
-	  {
-	    if (tmp->source_addr.sa.sa_family == AF_INET)
-	      tmp->source_addr.in.sin_port = htons(daemon->query_port);
+	{
+	  tmp->edns_pktsz = daemon->edns_pktsz;
+	 
+	  if (!(tmp->flags & SERV_HAS_SOURCE))
+	    {
+	      if (tmp->source_addr.sa.sa_family == AF_INET)
+		tmp->source_addr.in.sin_port = htons(daemon->query_port);
 #ifdef HAVE_IPV6
-	    else if (tmp->source_addr.sa.sa_family == AF_INET6)
-	      tmp->source_addr.in6.sin6_port = htons(daemon->query_port);
+	      else if (tmp->source_addr.sa.sa_family == AF_INET6)
+		tmp->source_addr.in6.sin6_port = htons(daemon->query_port);
 #endif 
-	  } 
+	    }
+	} 
     }
   
   if (daemon->if_addrs)

src/rfc1035.c

@@ -20,7 +20,7 @@ int extract_name(struct dns_header *header, size_t plen, unsigned char **pp,
 		 char *name, int isExtract, int extrabytes)
 {
   unsigned char *cp = (unsigned char *)name, *p = *pp, *p1 = NULL;
-  unsigned int j, l, hops = 0;
+  unsigned int j, l, namelen = 0, hops = 0;
   int retvalue = 1;
   
   if (isExtract)
@@ -94,9 +94,15 @@ int extract_name(struct dns_header *header, size_t plen, unsigned char **pp,
 	    count = 256;
 	  digs = ((count-1)>>2)+1;
 	  
-	  /* output is \[x<hex>/siz]. which is digs+9 chars */
-	  if (cp - (unsigned char *)name + digs + 9 >= MAXDNAME)
+	  /* output is \[x<hex>/siz]. which is digs+7/8/9 chars */
+	  namelen += digs+7;
+	  if (count > 9)
+	    namelen++;
+	  if (count > 99)
+	    namelen++;
+	  if (namelen+1 >= MAXDNAME)
 	    return 0;
+
 	  if (!CHECK_LEN(header, p, plen, (count-1)>>3))
 	    return 0;
 
@@ -119,7 +125,8 @@ int extract_name(struct dns_header *header, size_t plen, unsigned char **pp,
 	}
       else 
 	{ /* label_type = 0 -> label. */
-	  if (cp - (unsigned char *)name + l + 1 >= MAXDNAME)
+	  namelen += l + 1; /* include period */
+	  if (namelen >= MAXDNAME)
 	    return 0;
 	  if (!CHECK_LEN(header, p, plen, l))
 	    return 0;
@@ -128,8 +135,21 @@ 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+1;
+		      }
+		    else
+		      *cp++ = c; 
+		  }
+		else
+#endif
+		if (c != 0 && c != '.')
+		  *cp++ = c;
 		else
 		  return 0;
 	      }
@@ -144,9 +164,14 @@ 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++)-1;
+#endif
+		    
 		    if (c2 >= 'A' && c2 <= 'Z')
 		      c2 += 'a' - 'A';
-		    
+		     
 		    if (c1 != c2)
 		      retvalue =  2;
 		  }
@@ -527,7 +552,7 @@ static size_t add_pseudoheader(struct dns_header *header, size_t plen, unsigned
 	return plen;
       *p++ = 0; /* empty name */
       PUTSHORT(T_OPT, p);
-      PUTSHORT(daemon->edns_pktsz, p); /* max packet length */
+      PUTSHORT(SAFE_PKTSZ, p); /* max packet length, this will be overwritten */
       PUTSHORT(0, p);    /* extended RCODE and version */
       PUTSHORT(set_do ? 0x8000 : 0, p); /* DO flag */
       lenp = p;
@@ -1092,10 +1117,23 @@ int extract_addresses(struct dns_header *header, size_t qlen, char *name, time_t
 		      memcpy(&addr, p1, addrlen);
 		      
 		      /* check for returned address in private space */
-		      if (check_rebind &&
-			  (flags & F_IPV4) &&
-			  private_net(addr.addr.addr4, !option_bool(OPT_LOCAL_REBIND)))
-			return 1;
+		      if (check_rebind)
+			{
+			  if ((flags & F_IPV4) &&
+			      private_net(addr.addr.addr4, !option_bool(OPT_LOCAL_REBIND)))
+			    return 1;
+			  
+#ifdef HAVE_IPV6
+			  if ((flags & F_IPV6) &&
+			      IN6_IS_ADDR_V4MAPPED(&addr.addr.addr6))
+			    {
+			      struct in_addr v4;
+			      v4.s_addr = ((const uint32_t *) (&addr.addr.addr6))[3];
+			      if (private_net(v4, !option_bool(OPT_LOCAL_REBIND)))
+				return 1;
+			    }
+#endif
+			}
 		      
 #ifdef HAVE_IPSET
 		      if (ipsets && (flags & (F_IPV4 | F_IPV6)))
@@ -1198,7 +1236,10 @@ 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 +1255,7 @@ 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 +1263,7 @@ 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);
@@ -1509,7 +1550,6 @@ size_t answer_request(struct dns_header *header, char *limit, size_t qlen,
   unsigned short flag;
   int q, ans, anscount = 0, addncount = 0;
   int dryrun = 0, sec_reqd = 0, have_pseudoheader = 0;
-  int is_sign;
   struct crec *crecp;
   int nxdomain = 0, auth = 1, trunc = 0, sec_data = 1;
   struct mx_srv_record *rec;
@@ -1529,28 +1569,19 @@ size_t answer_request(struct dns_header *header, char *limit, size_t qlen,
      forward rather than answering from the cache, which doesn't include
      security information, unless we're in DNSSEC validation mode. */
 
-  if (find_pseudoheader(header, qlen, NULL, &pheader, &is_sign))
+  if (find_pseudoheader(header, qlen, NULL, &pheader, NULL))
     { 
-      unsigned short udpsz, flags;
-      unsigned char *psave = pheader;
-
+      unsigned short flags;
+      
       have_pseudoheader = 1;
 
-      GETSHORT(udpsz, pheader);
-      pheader += 2; /* ext_rcode */
+      pheader += 4; /* udp size, ext_rcode */
       GETSHORT(flags, pheader);
       
       if ((sec_reqd = flags & 0x8000))
 	*do_bit = 1;/* do bit */ 
+
       *ad_reqd = 1;
-
-      /* If our client is advertising a larger UDP packet size
-	 than we allow, trim it so that we don't get an overlarge
-	 response from upstream */
-
-      if (!is_sign && (udpsz > daemon->edns_pktsz))
-	PUTSHORT(daemon->edns_pktsz, psave); 
-
       dryrun = 1;
     }
 
@@ -1580,6 +1611,11 @@ size_t answer_request(struct dns_header *header, char *limit, size_t qlen,
       GETSHORT(qtype, p); 
       GETSHORT(qclass, p);
 
+      /* Don't filter RRSIGS from answers to ANY queries, even if do-bit
+	 not set. */
+      if (qtype == T_ANY)
+	*do_bit = 1;
+
       ans = 0; /* have we answered this question */
       
       if (qtype == T_TXT || qtype == T_ANY)

src/rfc2131.c

@@ -52,7 +52,9 @@ static void do_options(struct dhcp_context *context,
 		       int null_term, int pxearch,
 		       unsigned char *uuid,
 		       int vendor_class_len,
-		       time_t now);
+		       time_t now,
+		       unsigned int lease_time,
+		       unsigned short fuzz);
 
 
 static void match_vendor_opts(unsigned char *opt, struct dhcp_opt *dopt); 
@@ -610,7 +612,7 @@ size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
 	      
 	      clear_packet(mess, end);
 	      do_options(context, mess, end, NULL, hostname, get_domain(mess->yiaddr), 
-			 netid, subnet_addr, 0, 0, -1, NULL, vendor_class_len, now);
+			 netid, subnet_addr, 0, 0, -1, NULL, vendor_class_len, now, 0xffffffff, 0);
 	    }
 	}
       
@@ -886,10 +888,10 @@ size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
 		  
 		  option_put(mess, end, OPTION_MESSAGE_TYPE, 1, 
 			     mess_type == DHCPDISCOVER ? DHCPOFFER : DHCPACK);
-		  option_put(mess, end, OPTION_SERVER_IDENTIFIER, INADDRSZ, htonl(context->local.s_addr));
+		  option_put(mess, end, OPTION_SERVER_IDENTIFIER, INADDRSZ, htonl(tmp->local.s_addr));
 		  pxe_misc(mess, end, uuid);
 		  prune_vendor_opts(tagif_netid);
-		  do_encap_opts(pxe_opts(pxearch, tagif_netid, context->local, now), OPTION_VENDOR_CLASS_OPT, DHOPT_VENDOR_MATCH, mess, end, 0);
+		  do_encap_opts(pxe_opts(pxearch, tagif_netid, tmp->local, now), OPTION_VENDOR_CLASS_OPT, DHOPT_VENDOR_MATCH, mess, end, 0);
 		  
 		  log_packet("PXE", NULL, emac, emac_len, iface_name, ignore ? "proxy-ignored" : "proxy", NULL, mess->xid);
 		  log_tags(tagif_netid, ntohl(mess->xid));
@@ -1042,13 +1044,8 @@ size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
       option_put(mess, end, OPTION_SERVER_IDENTIFIER, INADDRSZ, ntohl(server_id(context, override, fallback).s_addr));
       option_put(mess, end, OPTION_LEASE_TIME, 4, time);
       /* T1 and T2 are required in DHCPOFFER by HP's wacky Jetdirect client. */
-      if (time != 0xffffffff)
-	{
-	  option_put(mess, end, OPTION_T1, 4, (time/2));
-	  option_put(mess, end, OPTION_T2, 4, (time*7)/8);
-	}
       do_options(context, mess, end, req_options, offer_hostname, get_domain(mess->yiaddr), 
-		 netid, subnet_addr, fqdn_flags, borken_opt, pxearch, uuid, vendor_class_len, now);
+		 netid, subnet_addr, fqdn_flags, borken_opt, pxearch, uuid, vendor_class_len, now, time, fuzz);
       
       return dhcp_packet_size(mess, agent_id, real_end);
       
@@ -1367,15 +1364,8 @@ size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
 	  option_put(mess, end, OPTION_MESSAGE_TYPE, 1, DHCPACK);
 	  option_put(mess, end, OPTION_SERVER_IDENTIFIER, INADDRSZ, ntohl(server_id(context, override, fallback).s_addr));
 	  option_put(mess, end, OPTION_LEASE_TIME, 4, time);
-	  if (time != 0xffffffff)
-	    {
-	      while (fuzz > (time/16))
-		fuzz = fuzz/2; 
-	      option_put(mess, end, OPTION_T1, 4, (time/2) - fuzz);
-	      option_put(mess, end, OPTION_T2, 4, ((time/8)*7) - fuzz);
-	    }
 	  do_options(context, mess, end, req_options, hostname, get_domain(mess->yiaddr), 
-		     netid, subnet_addr, fqdn_flags, borken_opt, pxearch, uuid, vendor_class_len, now);
+		     netid, subnet_addr, fqdn_flags, borken_opt, pxearch, uuid, vendor_class_len, now, time, fuzz);
 	}
 
       return dhcp_packet_size(mess, agent_id, real_end); 
@@ -1440,7 +1430,7 @@ size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
 	}
 
       do_options(context, mess, end, req_options, hostname, get_domain(mess->ciaddr),
-		 netid, subnet_addr, fqdn_flags, borken_opt, pxearch, uuid, vendor_class_len, now);
+		 netid, subnet_addr, fqdn_flags, borken_opt, pxearch, uuid, vendor_class_len, now, 0xffffffff, 0);
       
       *is_inform = 1; /* handle reply differently */
       return dhcp_packet_size(mess, agent_id, real_end); 
@@ -2137,7 +2127,9 @@ static void do_options(struct dhcp_context *context,
 		       int null_term, int pxe_arch,
 		       unsigned char *uuid,
 		       int vendor_class_len,
-		       time_t now)
+		       time_t now,
+		       unsigned int lease_time,
+		       unsigned short fuzz)
 {
   struct dhcp_opt *opt, *config_opts = daemon->dhcp_opts;
   struct dhcp_boot *boot;
@@ -2261,7 +2253,42 @@ static void do_options(struct dhcp_context *context,
   /* rfc3011 says this doesn't need to be in the requested options list. */
   if (subnet_addr.s_addr)
     option_put(mess, end, OPTION_SUBNET_SELECT, INADDRSZ, ntohl(subnet_addr.s_addr));
-  
+   
+  if (lease_time != 0xffffffff)
+    { 
+      unsigned int t1val = lease_time/2; 
+      unsigned int t2val = (lease_time*7)/8;
+      unsigned int hval;
+      
+      /* If set by user, sanity check, so not longer than lease. */
+      if ((opt = option_find2(OPTION_T1)))
+	{
+	  hval = ntohl(*((unsigned int *)opt->val));
+	  if (hval < lease_time && hval > 2)
+	    t1val = hval;
+	}
+
+       if ((opt = option_find2(OPTION_T2)))
+	{
+	  hval = ntohl(*((unsigned int *)opt->val));
+	  if (hval < lease_time && hval > 2)
+	    t2val = hval;
+	}
+       	  
+       /* ensure T1 is still < T2 */
+       if (t2val <= t1val)
+	 t1val = t2val - 1; 
+
+       while (fuzz > (t1val/8))
+	 fuzz = fuzz/2;
+	 
+       t1val -= fuzz;
+       t2val -= fuzz;
+       
+       option_put(mess, end, OPTION_T1, 4, t1val);
+       option_put(mess, end, OPTION_T2, 4, t2val);
+    }
+
   /* replies to DHCPINFORM may not have a valid context */
   if (context)
     {
@@ -2356,12 +2383,14 @@ static void do_options(struct dhcp_context *context,
       if (!(opt->flags & DHOPT_FORCE) && !in_list(req_options, optno))
 	continue;
       
-      /* prohibit some used-internally options */
+      /* prohibit some used-internally options. T1 and T2 already handled. */
       if (optno == OPTION_CLIENT_FQDN ||
 	  optno == OPTION_MAXMESSAGE ||
 	  optno == OPTION_OVERLOAD ||
 	  optno == OPTION_PAD ||
-	  optno == OPTION_END)
+	  optno == OPTION_END ||
+	  optno == OPTION_T1 ||
+	  optno == OPTION_T2)
 	continue;
 
       if (optno == OPTION_SNAME && done_server)

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;
@@ -1051,9 +1047,9 @@ static int dhcp6_no_relay(struct state *state, int msg_type, void *inbuff, size_
 		  {
 		    preferred_time = valid_time = 0;
 		    message = _("address invalid");
-		  }
+		  } 
 
-		if (message)
+		if (message && (message != state->hostname))
 		  log6_packet(state, "DHCPREPLY", req_addr, message);	
 		else
 		  log6_quiet(state, "DHCPREPLY", req_addr, message);

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))-1;
+	  else
+#endif		
+	    *p++ = *sval;
+	}
       *cp  = j;
       if (*sval)
 	sval++;