Change default lease time for DHCPv6 to one day.

Also remove floor on valid and preffered times in RA when
no time is specified.

CHANGELOG

@@ -10,6 +10,14 @@ version 2.82
 	Fix crash under heavy TCP connection load introdcued in 2.81.
 	Thanks to Frank for good work chasing this down.
 
+	Change default lease time for DHCPv6 to one day.
+
+	Alter calculation of preffered and valid times in router
+	advertisements, so that these do not have a floor applied
+	of the lease time in the dhcp-range if this is not explicitly
+	specified and is merely the default.
+	Thanks to Martin-Éric Racine for suggestions on this.
+
 	
 version 2.81
 	Improve cache behaviour for TCP connections. For ease of

man/dnsmasq.8

@@ -861,7 +861,7 @@ in
 options. If the lease time is given, then leases
 will be given for that length of time. The lease time is in seconds,
 or minutes (eg 45m) or hours (eg 1h) or "infinite". If not given,
-the default lease time is one hour. The
+the default lease time is one hour for IPv4 and one day for IPv6. The
 minimum lease time is two minutes. For IPv6 ranges, the lease time
 maybe "deprecated"; this sets the preferred lifetime sent in a DHCP
 lease or router advertisement to zero, which causes clients to use

src/config.h

@@ -43,7 +43,8 @@
 #define DNSSEC_MIN_TTL 60 /* DNSKEY and DS records in cache last at least this long */
 #define HOSTSFILE "/etc/hosts"
 #define ETHERSFILE "/etc/ethers"
-#define DEFLEASE 3600 /* default lease time, 1 hour */
+#define DEFLEASE 3600 /* default DHCPv4 lease time, one hour */
+#define DEFLEASE6 (3600*24) /* default lease time for DHCPv6. One day. */
 #define CHUSER "nobody"
 #define CHGRP "dip"
 #define TFTP_MAX_CONNECTIONS 50 /* max simultaneous connections */

src/dnsmasq.h

@@ -942,6 +942,7 @@ struct shared_network {
 #define CONTEXT_OLD            (1u<<16)
 #define CONTEXT_V6             (1u<<17)
 #define CONTEXT_RA_OFF_LINK    (1u<<18)
+#define CONTEXT_SETLEASE       (1u<<19)
 
 struct ping_result {
   struct in_addr addr;

src/option.c

@@ -2991,7 +2991,6 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 	struct dhcp_context *new = opt_malloc(sizeof(struct dhcp_context));
 	
 	memset (new, 0, sizeof(*new));
-	new->lease_time = DEFLEASE;
 	
 	while(1)
 	  {
@@ -3041,6 +3040,7 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 	if (inet_pton(AF_INET, a[0], &new->start))
 	  {
 	    new->next = daemon->dhcp;
+	    new->lease_time = DEFLEASE;
 	    daemon->dhcp = new;
 	    new->end = new->start;
 	    if (strcmp(a[1], "static") == 0)
@@ -3088,6 +3088,7 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 	    new->flags |= CONTEXT_V6; 
 	    new->prefix = 64; /* default */
 	    new->end6 = new->start6;
+	    new->lease_time = DEFLEASE6;
 	    new->next = daemon->dhcp6;
 	    daemon->dhcp6 = new;
 
@@ -3187,7 +3188,10 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 	      }
 	    
 	    if (strcmp(a[leasepos], "infinite") == 0)
+	      {
 		new->lease_time = 0xffffffff;
+		new->flags |= CONTEXT_SETLEASE;
+	      }
 	    else if (strcmp(a[leasepos], "deprecated") == 0)
 	      new->flags |= CONTEXT_DEPRECATE;
 	    else
@@ -3226,6 +3230,7 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 		      ret_err_free(_("bad dhcp-range"), new);
 		    
 		    new->lease_time = atoi(a[leasepos]) * fac;
+		    new->flags |= CONTEXT_SETLEASE;
 		    /* Leases of a minute or less confuse
 		       some clients, notably Apple's */
 		    if (new->lease_time < 120)
@@ -3233,6 +3238,7 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 		  }
 	      }
 	  }
+
 	break;
       }
 

src/radv.c

@@ -626,8 +626,11 @@ static int add_prefixes(struct in6_addr *local,  int prefix,
 		    real_prefix = context->prefix;
 		  }
 
-		/* find floor time, don't reduce below 3 * RA interval. */
+		/* find floor time, don't reduce below 3 * RA interval.
-		if (time > context->lease_time)
+		   If the lease time has been left as default, don't
+		   use that as a floor. */
+		if ((context->flags & CONTEXT_SETLEASE) &&
+		    time > context->lease_time)
 		  {
 		    time = context->lease_time;
 		    if (time < ((unsigned int)(3 * param->adv_interval)))