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

@@ -103,7 +103,23 @@ version 2.73
 	    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.
+ 	    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

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
+if which git >/dev/null 2>&1 && \
-     cd $1; git describe | sed 's/^v//'
+    ([ -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

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

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>.
 

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},
+  { "T1", 58, OT_TIME},
-  { "T2", 59, OT_INTERNAL | OT_TIME},
+  { "T2", 59, OT_TIME},
   { "vendor-class", 60, 0 },
   { "client-id", 61, OT_INTERNAL },
   { "nis+-domain", 64, OT_NAME },

src/dnsmasq.h

@@ -504,7 +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;
@@ -594,6 +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 */
@@ -1148,7 +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);
@@ -1304,9 +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,
+void lease_set_hwaddr(struct dhcp_lease *lease, const unsigned char *hwaddr,
-		      unsigned char *clid, int hw_len, int hw_type, int clid_len, time_t now, int force);
+		      const unsigned char *clid, int hw_len, int hw_type,
-void lease_set_hostname(struct dhcp_lease *lease, char *name, int auth, char *domain, char *config_domain);
+		      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

@@ -2162,10 +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);
@@ -2194,7 +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,
@@ -760,7 +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)
@@ -781,7 +797,14 @@ 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
@@ -890,7 +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 
 		    {
@@ -899,7 +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);
@@ -1526,7 +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);
       
@@ -1638,7 +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);
       
@@ -1996,8 +2019,9 @@ unsigned char *tcp_request(int confd, time_t now,
 			    }
 			  else
 			    result = (status == STAT_SECURE ? "SECURE" : (status == STAT_INSECURE ? "INSECURE" : "BOGUS"));
-			   if (status == STAT_BOGUS && extract_request(header, m, daemon->namebuff, NULL))
+			  
-			     domain = daemon->namebuff;
+			  if (status == STAT_BOGUS && extract_request(header, m, daemon->namebuff, NULL))
+			    domain = daemon->namebuff;
 
 			  log_query(F_KEYTAG | F_SECSTAT, domain, NULL, result);
 			  
@@ -2040,8 +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, bogusanswer,
+					option_bool(OPT_NO_REBIND) && !norebind, no_cache_dnssec, cache_secure, bogusanswer,
-					cache_secure, ad_question, do_bit, added_pheader, check_subnet, &peer_addr); 
+					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,
+void lease_set_hwaddr(struct dhcp_lease *lease, const unsigned char *hwaddr,
-		      unsigned char *clid, int hw_len, int hw_type, int clid_len, 
+		      const unsigned char *clid, int hw_len, int hw_type,
-		      time_t now, int force)
+		      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

@@ -4498,15 +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))
+	{
-	  {
+	  tmp->edns_pktsz = daemon->edns_pktsz;
-	    if (tmp->source_addr.sa.sa_family == AF_INET)
+	 
-	      tmp->source_addr.in.sin_port = htons(daemon->query_port);
+	  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)
+	      else if (tmp->source_addr.sa.sa_family == AF_INET6)
-	      tmp->source_addr.in6.sin6_port = htons(daemon->query_port);
+		tmp->source_addr.in6.sin6_port = htons(daemon->query_port);
 #endif 
-	  } 
+	    }
+	} 
     }
   
   if (daemon->if_addrs)

src/rfc1035.c

@@ -94,8 +94,8 @@ 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+6/7/8 chars */
+	  /* output is \[x<hex>/siz]. which is digs+7/8/9 chars */
-	  namelen += digs+6;
+	  namelen += digs+7;
 	  if (count > 9)
 	    namelen++;
 	  if (count > 99)
@@ -125,8 +125,8 @@ int extract_name(struct dns_header *header, size_t plen, unsigned char **pp,
 	}
       else 
 	{ /* label_type = 0 -> label. */
-	  namelen += l;
+	  namelen += l + 1; /* include period */
-	  if (namelen+1 >= MAXDNAME)
+	  if (namelen >= MAXDNAME)
 	    return 0;
 	  if (!CHECK_LEN(header, p, plen, l))
 	    return 0;
@@ -552,7 +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;
@@ -1117,10 +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 &&
+		      if (check_rebind)
-			  (flags & F_IPV4) &&
+			{
-			  private_net(addr.addr.addr4, !option_bool(OPT_LOCAL_REBIND)))
+			  if ((flags & F_IPV4) &&
-			return 1;
+			      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)))
@@ -1537,7 +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;
@@ -1557,28 +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 short flags;
-      unsigned char *psave = pheader;
+      
-
       have_pseudoheader = 1;
 
-      GETSHORT(udpsz, pheader);
+      pheader += 4; /* udp size, ext_rcode */
-      pheader += 2; /* 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;
     }
 
@@ -1608,6 +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

@@ -1047,9 +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);