Allow T1 and T2 DHCPv4 options to be set.

CHANGELOG

@@ -118,6 +118,9 @@ version 2.73
 	    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.

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

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/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);
 	    }
 	}
       
@@ -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;
@@ -2262,6 +2254,41 @@ static void do_options(struct dhcp_context *context,
   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;
+	}
+       	  
+       while (fuzz > (t1val/8))
+	 fuzz = fuzz/2;
+	 
+       t1val -= fuzz;
+       t2val -= fuzz;
+       
+       /* ensure T1 is still < T2 */
+       if (t2val <= t1val)
+	 t1val = t2val - 1; 
+
+       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)