Replace incoming EDNS0_OPTION_NOMDEVICEID and EDNS0_OPTION_NOMCPEID options.

CHANGELOG

@@ -48,6 +48,14 @@ version 2.76
 	    (ie xx::0 to xx::ffff:ffff:ffff:ffff) 
 	    Thanks to Laurent Bendel for spotting this problem.
 
+	    Add support for a TTL parameter in --host-record and
+	    --cname.
+
+	    Add --dhcp-ttl option.
+
+	    Add --tftp-mtu option. Thanks to Patrick McLean for the 
+	    initial patch.
+
 
 version 2.75
             Fix reversion on 2.74 which caused 100% CPU use when a 

man/dnsmasq.8

@@ -60,7 +60,7 @@ in the same way as for DHCP-derived names. Note that this does not
 apply to domain names in cnames, PTR records, TXT records etc.
 .TP
 .B \-T, --local-ttl=<time>
-When replying with information from /etc/hosts or the DHCP leases
+When replying with information from /etc/hosts or configuration or the DHCP leases
 file dnsmasq by default sets the time-to-live field to zero, meaning
 that the requester should not itself cache the information. This is
 the correct thing to do in almost all situations. This option allows a
@@ -68,6 +68,9 @@ time-to-live (in seconds) to be given for these replies. This will
 reduce the load on the server at the expense of clients using stale
 data under some circumstances.
 .TP
+.B --dhcp-ttl=<time>
+As for --local-ttl, but affects only replies with information from DHCP leases. If both are given, --dhcp-ttl applies for DHCP information, and --local-ttl for others. Setting this to zero eliminates the effect of --local-ttl for DHCP.
+.TP
 .B --neg-ttl=<time>
 Negative replies from upstream servers normally contain time-to-live
 information in SOA records which dnsmasq uses for caching. If the
@@ -529,7 +532,7 @@ zone files: the port, weight and priority numbers are in a different
 order. More than one SRV record for a given service/domain is allowed,
 all that match are returned.
 .TP
-.B --host-record=<name>[,<name>....],[<IPv4-address>],[<IPv6-address>]
+.B --host-record=<name>[,<name>....],[<IPv4-address>],[<IPv6-address>][,<TTL>]
 Add A, AAAA and PTR records to the DNS. This adds one or more names to
 the DNS with associated IPv4 (A) and IPv6 (AAAA) records. A name may
 appear in more than one 
@@ -546,6 +549,10 @@ is in effect. Short and long names may appear in the same
 .B host-record,
 eg. 
 .B --host-record=laptop,laptop.thekelleys.org,192.168.0.1,1234::100
+
+If the time-to-live is given, it overrides the default, which is zero
+or the value of --local-ttl. The value is a positive integer and gives 
+the time-to-live in seconds.
 .TP
 .B \-Y, --txt-record=<name>[[,<text>],<text>]
 Return a TXT DNS record. The value of TXT record is a set of strings,
@@ -559,7 +566,7 @@ Return a PTR DNS record.
 .B --naptr-record=<name>,<order>,<preference>,<flags>,<service>,<regexp>[,<replacement>]
 Return an NAPTR DNS record, as specified in RFC3403.
 .TP
-.B --cname=<cname>,<target>
+.B --cname=<cname>,<target>[,<TTL>]
 Return a CNAME record which indicates that <cname> is really
 <target>. There are significant limitations on the target; it must be a
 DNS name which is known to dnsmasq from /etc/hosts (or additional
@@ -568,6 +575,10 @@ hosts files), from DHCP, from --interface-name or from another
 If the target does not satisfy this
 criteria, the whole cname is ignored. The cname must be unique, but it
 is permissable to have more than one cname pointing to the same target.
+
+If the time-to-live is given, it overrides the default, which is zero
+or the value of -local-ttl. The value is a positive integer and gives 
+the time-to-live in seconds.
 .TP
 .B --dns-rr=<name>,<RR-number>,[<hex data>]
 Return an arbitrary DNS Resource Record. The number is the type of the
@@ -1799,6 +1810,10 @@ require about (2*n) + 10 descriptors. If
 .B --tftp-port-range
 is given, that can affect the number of concurrent connections.
 .TP
+.B --tftp-mtu=<mtu size>
+Use size as the ceiling of the MTU supported by the intervening network when 
+negotiating TFTP blocksize, overriding the MTU setting of the local interface  if it is larger.
+.TP
 .B --tftp-no-blocksize
 Stop the TFTP server from negotiating the "blocksize" option with a
 client. Some buggy clients request this option but then behave badly

src/auth.c

@@ -824,7 +824,7 @@ size_t answer_auth(struct dns_header *header, char *limit, size_t qlen, time_t n
 
   /* Advertise our packet size limit in our reply */
   if (have_pseudoheader)
-    return add_pseudoheader(header,  ansp - (unsigned char *)header, (unsigned char *)limit, daemon->edns_pktsz, 0, NULL, 0, do_bit);
+    return add_pseudoheader(header,  ansp - (unsigned char *)header, (unsigned char *)limit, daemon->edns_pktsz, 0, NULL, 0, do_bit, 0);
 
   return ansp - (unsigned char *)header;
 }

src/cache.c

@@ -778,6 +778,7 @@ static void add_hosts_cname(struct crec *target)
 	(crec = whine_malloc(sizeof(struct crec))))
       {
 	crec->flags = F_FORWARD | F_IMMORTAL | F_NAMEP | F_CONFIG | F_CNAME;
+	crec->ttd = a->ttl;
 	crec->name.namep = a->alias;
 	crec->addr.cname.target.cache = target;
 	crec->addr.cname.uid = target->uid;
@@ -981,6 +982,7 @@ int read_hostsfile(char *filename, unsigned int index, int cache_size, struct cr
 		  strcat(cache->name.sname, ".");
 		  strcat(cache->name.sname, domain_suffix);
 		  cache->flags = flags;
+		  cache->ttd = daemon->local_ttl;
 		  add_hosts_entry(cache, &addr, addrlen, index, rhash, hashsz);
 		  name_count++;
 		}
@@ -988,6 +990,7 @@ int read_hostsfile(char *filename, unsigned int index, int cache_size, struct cr
 		{
 		  strcpy(cache->name.sname, canon);
 		  cache->flags = flags;
+		  cache->ttd = daemon->local_ttl;
 		  add_hosts_entry(cache, &addr, addrlen, index, rhash, hashsz);
 		  name_count++;
 		}
@@ -1057,6 +1060,7 @@ void cache_reload(void)
 	  ((cache = whine_malloc(sizeof(struct crec)))))
 	{
 	  cache->flags = F_FORWARD | F_NAMEP | F_CNAME | F_IMMORTAL | F_CONFIG;
+	  cache->ttd = a->ttl;
 	  cache->name.namep = a->alias;
 	  cache->addr.cname.target.int_name = intr;
 	  cache->addr.cname.uid = SRC_INTERFACE;
@@ -1071,6 +1075,7 @@ void cache_reload(void)
 	(cache->addr.ds.keydata = blockdata_alloc(ds->digest, ds->digestlen)))
       {
 	cache->flags = F_FORWARD | F_IMMORTAL | F_DS | F_CONFIG | F_NAMEP;
+	cache->ttd = daemon->local_ttl;
 	cache->name.namep = ds->name;
 	cache->addr.ds.keylen = ds->digestlen;
 	cache->addr.ds.algo = ds->algo;
@@ -1095,6 +1100,7 @@ void cache_reload(void)
 	    (cache = whine_malloc(sizeof(struct crec))))
 	  {
 	    cache->name.namep = nl->name;
+	    cache->ttd = hr->ttl;
 	    cache->flags = F_HOSTS | F_IMMORTAL | F_FORWARD | F_REVERSE | F_IPV4 | F_NAMEP | F_CONFIG;
 	    add_hosts_entry(cache, (struct all_addr *)&hr->addr, INADDRSZ, SRC_CONFIG, (struct crec **)daemon->packet, revhashsz);
 	  }
@@ -1103,6 +1109,7 @@ void cache_reload(void)
 	    (cache = whine_malloc(sizeof(struct crec))))
 	  {
 	    cache->name.namep = nl->name;
+	    cache->ttd = hr->ttl;
 	    cache->flags = F_HOSTS | F_IMMORTAL | F_FORWARD | F_REVERSE | F_IPV6 | F_NAMEP | F_CONFIG;
 	    add_hosts_entry(cache, (struct all_addr *)&hr->addr6, IN6ADDRSZ, SRC_CONFIG, (struct crec **)daemon->packet, revhashsz);
 	  }

src/dnsmasq.h

@@ -308,6 +308,7 @@ struct ptr_record {
 };
 
 struct cname {
+  int ttl;
   char *alias, *target;
   struct cname *next;
 }; 
@@ -344,6 +345,7 @@ struct auth_zone {
 
 
 struct host_record {
+  int ttl;
   struct name_list {
     char *name;
     struct name_list *next;
@@ -953,7 +955,7 @@ extern struct daemon {
   int max_logs;  /* queue limit */
   int cachesize, ftabsize;
   int port, query_port, min_port, max_port;
-  unsigned long local_ttl, neg_ttl, max_ttl, min_cache_ttl, max_cache_ttl, auth_ttl;
+  unsigned long local_ttl, neg_ttl, max_ttl, min_cache_ttl, max_cache_ttl, auth_ttl, dhcp_ttl, use_dhcp_ttl;
   char *dns_client_id;
   struct hostsfile *addn_hosts;
   struct dhcp_context *dhcp, *dhcp6;
@@ -973,7 +975,7 @@ extern struct daemon {
   struct dhcp_netid_list *dhcp_ignore, *dhcp_ignore_names, *dhcp_gen_names; 
   struct dhcp_netid_list *force_broadcast, *bootp_dynamic;
   struct hostsfile *dhcp_hosts_file, *dhcp_opts_file, *dynamic_dirs;
-  int dhcp_max, tftp_max;
+  int dhcp_max, tftp_max, tftp_mtu;
   int dhcp_server_port, dhcp_client_port;
   int start_tftp_port, end_tftp_port; 
   unsigned int min_leasetime;
@@ -1521,7 +1523,7 @@ int expand_workspace(unsigned char ***wkspc, int *szp, int new);
 unsigned char *find_pseudoheader(struct dns_header *header, size_t plen,
 				   size_t *len, unsigned char **p, int *is_sign, int *is_last);
 size_t add_pseudoheader(struct dns_header *header, size_t plen, unsigned char *limit, 
-			unsigned short udp_sz, int optno, unsigned char *opt, size_t optlen, int set_do);
+			unsigned short udp_sz, int optno, unsigned char *opt, size_t optlen, int set_do, int replace);
 size_t add_do_bit(struct dns_header *header, size_t plen, unsigned char *limit);
 size_t add_edns0_config(struct dns_header *header, size_t plen, unsigned char *limit, 
 			union mysockaddr *source, time_t now, int *check_subnet);

src/edns0.c

@@ -96,7 +96,7 @@ unsigned char *find_pseudoheader(struct dns_header *header, size_t plen, size_t
 }
  
 size_t add_pseudoheader(struct dns_header *header, size_t plen, unsigned char *limit, 
-			unsigned short udp_sz, int optno, unsigned char *opt, size_t optlen, int set_do)
+			unsigned short udp_sz, int optno, unsigned char *opt, size_t optlen, int set_do, int replace)
 { 
   unsigned char *lenp, *datap, *p, *udp_len, *buff = NULL;
   int rdlen = 0, is_sign, is_last;
@@ -120,7 +120,7 @@ size_t add_pseudoheader(struct dns_header *header, size_t plen, unsigned char *l
 
       if (set_do)
 	{
-	  p -=2;
+	  p -= 2;
 	  flags |= 0x8000;
 	  PUTSHORT(flags, p);
 	}
@@ -136,13 +136,36 @@ size_t add_pseudoheader(struct dns_header *header, size_t plen, unsigned char *l
 	return plen;
       	  
       /* check if option already there */
-      for (i = 0; i + 4 < rdlen; i += len + 4)
+      for (i = 0; i + 4 < rdlen;)
 	{
 	  GETSHORT(code, p);
 	  GETSHORT(len, p);
+	  
+	  /* malformed option, delete the whole OPT RR and start again. */
+	  if (i + len > rdlen)
+	    {
+	      rdlen = 0;
+	      islast = 0;
+	      break;
+	    }
+	  
 	  if (code == optno)
-	    return plen;
+	    {
-	  p += len;
+	      if (!replace)
+		return plen;
+
+	      /* delete option if we're to replace it. */
+	      p -= 4;
+	      rdlen -= len + 4;
+	      memcpy(p, p+len+4, rdlen - i);
+	      PUTSHORT(rdlen, lenp);
+	      lenp -= 2;
+	    }
+	  else
+	    {
+	      p += len;
+	      i += len + 4;
+	    }
 	}
 
       /* If we're going to extend the RR, it has to be the last RR in the packet */
@@ -203,7 +226,7 @@ size_t add_pseudoheader(struct dns_header *header, size_t plen, unsigned char *l
 
 size_t add_do_bit(struct dns_header *header, size_t plen, unsigned char *limit)
 {
-  return add_pseudoheader(header, plen, (unsigned char *)limit, PACKETSZ, 0, NULL, 0, 1);
+  return add_pseudoheader(header, plen, (unsigned char *)limit, PACKETSZ, 0, NULL, 0, 1, 0);
 }
 
 static unsigned char char64(unsigned char c)
@@ -235,7 +258,7 @@ static size_t add_dns_client(struct dns_header *header, size_t plen, unsigned ch
 	  encoder(mac+3, encode+4);
 	  encode[8] = 0;
 	}
-      plen = add_pseudoheader(header, plen, limit, PACKETSZ, EDNS0_OPTION_NOMDEVICEID, (unsigned char *)encode, strlen(encode), 0); 
+      plen = add_pseudoheader(header, plen, limit, PACKETSZ, EDNS0_OPTION_NOMDEVICEID, (unsigned char *)encode, strlen(encode), 0, 1); 
     }
 
   return plen; 
@@ -248,7 +271,7 @@ static size_t add_mac(struct dns_header *header, size_t plen, unsigned char *lim
   unsigned char mac[DHCP_CHADDR_MAX];
 
   if ((maclen = find_mac(l3, mac, 1, now)) != 0)
-    plen = add_pseudoheader(header, plen, limit, PACKETSZ, EDNS0_OPTION_MAC, mac, maclen, 0); 
+    plen = add_pseudoheader(header, plen, limit, PACKETSZ, EDNS0_OPTION_MAC, mac, maclen, 0, 0); 
     
   return plen; 
 }
@@ -281,8 +304,11 @@ static size_t calc_subnet_opt(struct subnet_opt *opt, union mysockaddr *source)
   void *addrp;
   int sa_family = source->sa.sa_family;
 
+  opt->source_netmask = 0;
+  opt->scope_netmask = 0;
+
 #ifdef HAVE_IPV6
-  if (source->sa.sa_family == AF_INET6)
+  if (source->sa.sa_family == AF_INET6 && daemon->add_subnet6)
     {
       opt->source_netmask = daemon->add_subnet6->mask;
       if (daemon->add_subnet6->addr_used) 
@@ -293,8 +319,9 @@ static size_t calc_subnet_opt(struct subnet_opt *opt, union mysockaddr *source)
       else 
 	addrp = &source->in6.sin6_addr;
     }
-  else
 #endif
+
+  if (source->sa.sa_family == AF_INET && daemon->add_subnet4)
     {
       opt->source_netmask = daemon->add_subnet4->mask;
       if (daemon->add_subnet4->addr_used)
@@ -302,20 +329,20 @@ static size_t calc_subnet_opt(struct subnet_opt *opt, union mysockaddr *source)
 	  sa_family = daemon->add_subnet4->addr.sa.sa_family;
 	  addrp = get_addrp(&daemon->add_subnet4->addr, sa_family);
 	} 
-      else 
+	else 
-	addrp = &source->in.sin_addr;
+	  addrp = &source->in.sin_addr;
     }
   
-  opt->scope_netmask = 0;
+#ifdef HAVE_IPV6
+  opt->family = htons(sa_family == AF_INET6 ? 2 : 1);
+#else
+  opt->family = htons(1);
+#endif
+  
   len = 0;
   
   if (opt->source_netmask != 0)
     {
-#ifdef HAVE_IPV6
-      opt->family = htons(sa_family == AF_INET6 ? 2 : 1);
-#else
-      opt->family = htons(1);
-#endif
       len = ((opt->source_netmask - 1) >> 3) + 1;
       memcpy(opt->addr, addrp, len);
       if (opt->source_netmask & 7)
@@ -333,7 +360,7 @@ static size_t add_source_addr(struct dns_header *header, size_t plen, unsigned c
   struct subnet_opt opt;
   
   len = calc_subnet_opt(&opt, source);
-  return add_pseudoheader(header, plen, (unsigned char *)limit, PACKETSZ, EDNS0_OPTION_CLIENT_SUBNET, (unsigned char *)&opt, len, 0);
+  return add_pseudoheader(header, plen, (unsigned char *)limit, PACKETSZ, EDNS0_OPTION_CLIENT_SUBNET, (unsigned char *)&opt, len, 0, 0);
 }
 
 int check_source(struct dns_header *header, size_t plen, unsigned char *pseudoheader, union mysockaddr *peer)
@@ -387,7 +414,7 @@ size_t add_edns0_config(struct dns_header *header, size_t plen, unsigned char *l
 
   if (daemon->dns_client_id)
     plen = add_pseudoheader(header, plen, limit, PACKETSZ, EDNS0_OPTION_NOMCPEID, 
-			    (unsigned char *)daemon->dns_client_id, strlen(daemon->dns_client_id), 0);
+			    (unsigned char *)daemon->dns_client_id, strlen(daemon->dns_client_id), 0, 1);
   
   if (option_bool(OPT_CLIENT_SUBNET))
     {

src/option.c

@@ -157,6 +157,8 @@ struct myoption {
 #define LOPT_MAXPORT       345
 #define LOPT_CPE_ID        346
 #define LOPT_SCRIPT_ARP    347
+#define LOPT_DHCPTTL       348
+#define LOPT_TFTP_MTU      349
  
 #ifdef HAVE_GETOPT_LONG
 static const struct option opts[] =  
@@ -243,6 +245,7 @@ static const struct myoption opts[] =
     { "tftp-unique-root", 0, 0, LOPT_APREF },
     { "tftp-root", 1, 0, LOPT_PREFIX },
     { "tftp-max", 1, 0, LOPT_TFTP_MAX },
+    { "tftp-mtu", 1, 0, LOPT_TFTP_MTU },
     { "tftp-lowercase", 0, 0, LOPT_TFTP_LC },
     { "ptr-record", 1, 0, LOPT_PTR },
     { "naptr-record", 1, 0, LOPT_NAPTR },
@@ -319,6 +322,7 @@ static const struct myoption opts[] =
     { "quiet-ra", 0, 0, LOPT_QUIET_RA },
     { "dns-loop-detect", 0, 0, LOPT_LOOP_DETECT },
     { "script-arp", 0, 0, LOPT_SCRIPT_ARP },
+    { "dhcp-ttl", 1, 0 , LOPT_DHCPTTL },
     { NULL, 0, 0, 0 }
   };
 
@@ -430,6 +434,7 @@ static struct {
   { 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_TFTP_MTU, ARG_ONE, "<integer>", gettext_noop("Maximum MTU to use for TFTP transfers."), NULL },
   { 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 },
   { LOPT_TFTPPORTS, ARG_ONE, "<start>,<end>", gettext_noop("Ephemeral port range for use by TFTP transfers."), NULL },
@@ -448,20 +453,20 @@ static struct {
   { LOPT_GEN_NAMES, ARG_DUP, "[=tag:<tag>]", gettext_noop("Generate hostnames based on MAC address for nameless clients."), NULL},
   { LOPT_PROXY, ARG_DUP, "[=<ipaddr>]...", gettext_noop("Use these DHCP relays as full proxies."), NULL },
   { LOPT_RELAY, ARG_DUP, "<local-addr>,<server>[,<interface>]", gettext_noop("Relay DHCP requests to a remote server"), NULL},
-  { LOPT_CNAME, ARG_DUP, "<alias>,<target>", gettext_noop("Specify alias name for LOCAL DNS name."), NULL },
+  { LOPT_CNAME, ARG_DUP, "<alias>,<target>[,<ttl>]", gettext_noop("Specify alias name for LOCAL DNS name."), NULL },
   { LOPT_PXE_PROMT, ARG_DUP, "<prompt>,[<timeout>]", gettext_noop("Prompt to send to PXE clients."), NULL },
   { LOPT_PXE_SERV, ARG_DUP, "<service>", gettext_noop("Boot service for PXE menu."), NULL },
   { LOPT_TEST, 0, NULL, gettext_noop("Check configuration syntax."), NULL },
   { LOPT_ADD_MAC, ARG_DUP, "[=base64|text]", gettext_noop("Add requestor's MAC address to forwarded DNS queries."), NULL },
   { LOPT_ADD_SBNET, ARG_ONE, "<v4 pref>[,<v6 pref>]", gettext_noop("Add specified IP subnet to forwarded DNS queries."), NULL },
-   { LOPT_CPE_ID, ARG_ONE, "<text>", gettext_noop("Add client identification to forwarded DNS queries."), NULL },
+  { LOPT_CPE_ID, ARG_ONE, "<text>", gettext_noop("Add client identification to forwarded DNS queries."), NULL },
   { LOPT_DNSSEC, OPT_DNSSEC_PROXY, NULL, gettext_noop("Proxy DNSSEC validation results from upstream nameservers."), NULL },
   { LOPT_INCR_ADDR, OPT_CONSEC_ADDR, NULL, gettext_noop("Attempt to allocate sequential IP addresses to DHCP clients."), NULL },
   { LOPT_CONNTRACK, OPT_CONNTRACK, NULL, gettext_noop("Copy connection-track mark from queries to upstream connections."), NULL },
   { LOPT_FQDN, OPT_FQDN_UPDATE, NULL, gettext_noop("Allow DHCP clients to do their own DDNS updates."), NULL },
   { LOPT_RA, OPT_RA, NULL, gettext_noop("Send router-advertisements for interfaces doing DHCPv6"), NULL },
   { LOPT_DUID, ARG_ONE, "<enterprise>,<duid>", gettext_noop("Specify DUID_EN-type DHCPv6 server DUID"), NULL },
-  { LOPT_HOST_REC, ARG_DUP, "<name>,<address>", gettext_noop("Specify host (A/AAAA and PTR) records"), NULL },
+  { LOPT_HOST_REC, ARG_DUP, "<name>,<address>[,<ttl>]", gettext_noop("Specify host (A/AAAA and PTR) records"), NULL },
   { LOPT_RR, ARG_DUP, "<name>,<RR-number>,[<data>]", gettext_noop("Specify arbitrary DNS resource record"), NULL },
   { LOPT_CLVERBIND, OPT_CLEVERBIND, NULL, gettext_noop("Bind to interfaces in use - check for new interfaces"), NULL },
   { LOPT_AUTHSERV, ARG_ONE, "<NS>,<interface>", gettext_noop("Export local names to global DNS"), NULL },
@@ -485,9 +490,10 @@ static struct {
   { LOPT_QUIET_DHCP, OPT_QUIET_DHCP, NULL, gettext_noop("Do not log routine DHCP."), NULL },
   { LOPT_QUIET_DHCP6, OPT_QUIET_DHCP6, NULL, gettext_noop("Do not log routine DHCPv6."), NULL },
   { LOPT_QUIET_RA, OPT_QUIET_RA, NULL, gettext_noop("Do not log RA."), NULL },
-  { LOPT_LOCAL_SERVICE, OPT_LOCAL_SERVICE, NULL, gettext_noop("Accept queries only from directly-connected networks"), NULL },
+  { LOPT_LOCAL_SERVICE, OPT_LOCAL_SERVICE, NULL, gettext_noop("Accept queries only from directly-connected networks."), NULL },
-  { LOPT_LOOP_DETECT, OPT_LOOP_DETECT, NULL, gettext_noop("Detect and remove DNS forwarding loops"), NULL },
+  { LOPT_LOOP_DETECT, OPT_LOOP_DETECT, NULL, gettext_noop("Detect and remove DNS forwarding loops."), NULL },
   { LOPT_IGNORE_ADDR, ARG_DUP, "<ipaddr>", gettext_noop("Ignore DNS responses containing ipaddr."), NULL }, 
+  { LOPT_DHCPTTL, ARG_ONE, "<ttl>", gettext_noop("Set TTL in DNS responses with DHCP-derived addresses."), NULL }, 
   { 0, 0, NULL, NULL, NULL }
 }; 
 
@@ -1641,12 +1647,12 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 	    
           daemon->add_subnet4 = new;
 
-          new = opt_malloc(sizeof(struct mysubnet));
           if (comma)
             {
-              if ((end = split_chr(comma, '/')))
+	      new = opt_malloc(sizeof(struct mysubnet));
-                {
+	      if ((end = split_chr(comma, '/')))
-                  /* has subnet+len */
+		{
+		  /* has subnet+len */
                   err = parse_mysockaddr(comma, &new->addr);
                   if (err)
                     ret_err(err);
@@ -1659,8 +1665,9 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
                   if (!atoi_check(comma, &new->mask))
                     ret_err(gen_err);
                 }
-            }
+          
-          daemon->add_subnet6 = new;
+	      daemon->add_subnet6 = new;
+	    }
 	}
       break;
 
@@ -2164,7 +2171,7 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 	daemon->dns_client_id = opt_string_alloc(arg);
       break;
 
-    case LOPT_ADD_MAC:
+    case LOPT_ADD_MAC: /* --add-mac */
       if (!arg)
 	set_option_bool(OPT_ADD_MAC);
       else
@@ -2580,6 +2587,7 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
     case LOPT_MINCTTL: /* --min-cache-ttl */
     case LOPT_MAXCTTL: /* --max-cache-ttl */
     case LOPT_AUTHTTL: /* --auth-ttl */
+    case LOPT_DHCPTTL: /* --dhcp-ttl */
       {
 	int ttl;
 	if (!atoi_check(arg, &ttl))
@@ -2598,6 +2606,11 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 	  daemon->max_cache_ttl = (unsigned long)ttl;
 	else if (option == LOPT_AUTHTTL)
 	  daemon->auth_ttl = (unsigned long)ttl;
+	else if (option == LOPT_DHCPTTL)
+	  {
+	    daemon->dhcp_ttl = (unsigned long)ttl;
+	    daemon->use_dhcp_ttl = 1;
+	  }
 	else
 	  daemon->local_ttl = (unsigned long)ttl;
 	break;
@@ -2616,6 +2629,11 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 	ret_err(gen_err);
       break;  
 
+    case LOPT_TFTP_MTU:  /*  --tftp-mtu */
+      if (!atoi_check(arg, &daemon->tftp_mtu))
+	ret_err(gen_err);
+      break;
+
     case LOPT_PREFIX: /* --tftp-prefix */
       comma = split(arg);
       if (comma)
@@ -3692,12 +3710,15 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
     case LOPT_CNAME: /* --cname */
       {
 	struct cname *new;
-	char *alias;
+	char *alias, *target, *ttls;
-	char *target;
+	int ttl = -1;
 
 	if (!(comma = split(arg)))
 	  ret_err(gen_err);
 	
+	if ((ttls = split(comma)) && !atoi_check(ttls, &ttl))
+	  ret_err(_("bad TTL"));
+	
 	alias = canonicalise_opt(arg);
 	target = canonicalise_opt(comma);
 	    
@@ -3713,6 +3734,7 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 	    daemon->cnames = new;
 	    new->alias = alias;
 	    new->target = target;
+	    new->ttl = ttl;
 	  }
       
 	break;
@@ -3913,6 +3935,7 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
       {
 	struct host_record *new = opt_malloc(sizeof(struct host_record));
 	memset(new, 0, sizeof(struct host_record));
+	new->ttl = -1;
 
 	if (!arg || !(comma = split(arg)))
 	  ret_err(_("Bad host-record"));
@@ -3920,7 +3943,14 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 	while (arg)
 	  {
 	    struct all_addr addr;
-	    if (inet_pton(AF_INET, arg, &addr))
+	    char *dig;
+
+	    for (dig = arg; *dig != 0; dig++)
+	      if (*dig < '0' || *dig > '9')
+		break;
+	    if (*dig == 0)
+	      new->ttl = atoi(arg);
+	    else if (inet_pton(AF_INET, arg, &addr))
 	      new->addr = addr.addr.addr4;
 #ifdef HAVE_IPV6
 	    else if (inet_pton(AF_INET6, arg, &addr))
@@ -4602,6 +4632,24 @@ void read_opts(int argc, char **argv, char *compile_opts)
 	} 
     }
 
+  if (daemon->host_records)
+    {
+      struct host_record *hr;
+      
+      for (hr = daemon->host_records; hr; hr = hr->next)
+	if (hr->ttl == -1)
+	  hr->ttl = daemon->local_ttl;
+    }
+
+  if (daemon->cnames)
+    {
+      struct cname *cn;
+      
+      for (cn = daemon->cnames; cn; cn = cn->next)
+	if (cn->ttl == -1)
+	  cn->ttl = daemon->local_ttl;
+    }
+
   if (daemon->if_addrs)
     {  
       struct iname *tmp;

src/rfc1035.c

@@ -1167,10 +1167,22 @@ int add_resource_record(struct dns_header *header, char *limit, int *truncp, int
 static unsigned long crec_ttl(struct crec *crecp, time_t now)
 {
   /* Return 0 ttl for DHCP entries, which might change
-     before the lease expires. */
+     before the lease expires, unless configured otherwise. */
 
-  if  (crecp->flags & (F_IMMORTAL | F_DHCP))
+  if (crecp->flags & F_DHCP)
-    return daemon->local_ttl;
+    {
+      int conf_ttl = daemon->use_dhcp_ttl ? daemon->dhcp_ttl : daemon->local_ttl;
+      
+      /* Apply ceiling of actual lease length to configured TTL. */
+      if (!(crecp->flags & F_IMMORTAL) && (crecp->ttd - now) < conf_ttl)
+	return crecp->ttd - now;
+      
+      return conf_ttl;
+    }	  
+  
+  /* Immortal entries other than DHCP are local, and hold TTL in TTD field. */
+  if (crecp->flags & F_IMMORTAL)
+    return crecp->ttd;
 
   /* Return the Max TTL value if it is lower then the actual TTL */
   if (daemon->max_ttl == 0 || ((unsigned)(crecp->ttd - now) < daemon->max_ttl))
@@ -1835,7 +1847,7 @@ size_t answer_request(struct dns_header *header, char *limit, size_t qlen,
   
   /* Advertise our packet size limit in our reply */
   if (have_pseudoheader)
-    len = add_pseudoheader(header, len, (unsigned char *)limit, daemon->edns_pktsz, 0, NULL, 0, do_bit);
+    len = add_pseudoheader(header, len, (unsigned char *)limit, daemon->edns_pktsz, 0, NULL, 0, do_bit, 0);
   
   if (ad_reqd && sec_data)
     header->hb4 |= HB4_AD;

src/tftp.c

@@ -103,8 +103,10 @@ void tftp_request(struct listener *listen, time_t now)
       if (listen->iface)
 	{
 	  addr = listen->iface->addr;
-	  mtu = listen->iface->mtu;
 	  name = listen->iface->name;
+	  mtu = listen->iface->mtu;
+	  if (daemon->tftp_mtu != 0 && daemon->tftp_mtu < mtu)
+	    mtu = daemon->tftp_mtu;
 	}
       else
 	{
@@ -234,9 +236,17 @@ void tftp_request(struct listener *listen, time_t now)
 
       strncpy(ifr.ifr_name, name, IF_NAMESIZE);
       if (ioctl(listen->tftpfd, SIOCGIFMTU, &ifr) != -1)
-	mtu = ifr.ifr_mtu;      
+	{
+	  mtu = ifr.ifr_mtu;  
+	  if (daemon->tftp_mtu != 0 && daemon->tftp_mtu < mtu)
+	    mtu = daemon->tftp_mtu;    
+	}
     }
 
+  /* Failed to get interface mtu - can use configured value. */
+  if (mtu == 0)
+    mtu = daemon->tftp_mtu;
+
   if (name)
     {
       /* check for per-interface prefix */