Calculate the lease time fields (expiry, renew, rebind) after

applying the option directives (ignore, default, supersede) from
dhclient.conf.

This allows the options dhcp-lease-time, dhcp-rebinding-time,
and dhcp-renewal-time to be controlled via dhclient.conf.

Also set BOOTP lease times by faking up these options rather than
crudely jamming in fixed times, allowing them to become configurable
via dhclient.conf.

Imperviousness of the time options pointed out by todd@.

1 files changed, 49 insertions, 29 deletions

diff --git a/sbin/dhclient/dhclient.c b/sbin/dhclient/dhclient.c
index 7c4fa718144..38511404c7e 100644
--- a/sbin/dhclient/dhclient.c
+++ b/sbin/dhclient/dhclient.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dhclient.c,v 1.261 2013/08/14 13:52:53 florian Exp $	*/
+/*	$OpenBSD: dhclient.c,v 1.262 2013/09/09 20:30:05 krw Exp $	*/
 
 /*
  * Copyright 2004 Henning Brauer <henning@openbsd.org>
@@ -679,20 +679,39 @@ state_selecting(void)
 
 	time(&cur_time);
 
-	/* If it was a BOOTREPLY, we can just take the address right now. */
+	/* If it was a BOOTREPLY, we can just take the lease right now. */
 	if (!picked->options[DHO_DHCP_MESSAGE_TYPE].len) {
+		struct option_data *option;
+
 		client->new = picked;
 
-		/* Make up some lease expiry times
-		   XXX these should be configurable. */
-		client->new->expiry = cur_time + 12000;
-		client->new->renewal += cur_time + 8000;
-		client->new->rebind += cur_time + 10000;
+		/*
+		 * Fake up DHO_DHCP_LEASE_TIME, DHO_RENEWAL_TIME and
+		 * DHO_REBINDING_TIME options so bind_lease() can
+		 * set the times.
+		 */
+		option = &client->new->options[DHO_DHCP_LEASE_TIME];
+		option->data = malloc(4);
+		if (option->data) {
+			option->len = 4;
+			putULong(option->data, 12000);
+		}
+		option = &client->new->options[DHO_DHCP_RENEWAL_TIME];
+		option->data = malloc(4);
+		if (option->data) {
+			option->len = 4;
+			putULong(option->data, 8000);
+		}
+		option = &client->new->options[DHO_DHCP_REBINDING_TIME];
+		option->data = malloc(4);
+		if (option->data) {
+			option->len = 4;
+			putULong(option->data, 10000);
+		}
 
 		client->state = S_REQUESTING;
-
-		/* Bind to the address we received. */
 		bind_lease();
+
 		return;
 	}
 
@@ -718,7 +737,6 @@ void
 dhcpack(struct in_addr client_addr, struct option_data *options, char *info)
 {
 	struct client_lease *lease;
-	time_t cur_time;
 
 	if (client->state != S_REBOOTING &&
 	    client->state != S_REQUESTING &&
@@ -743,12 +761,27 @@ dhcpack(struct in_addr client_addr, struct option_data *options, char *info)
 	/* Stop resending DHCPREQUEST. */
 	cancel_timeout();
 
+	bind_lease();
+}
+
+void
+bind_lease(void)
+{
+	struct in_addr gateway, mask;
+	struct option_data *options;
+	struct client_lease *lease;
+	time_t cur_time;
+
+	lease = apply_defaults(client->new);
+	options = lease->options;
+
 	/* Figure out the lease time. */
-	if (client->new->options[DHO_DHCP_LEASE_TIME].data)
+	if (options[DHO_DHCP_LEASE_TIME].data)
 		client->new->expiry =
-		    getULong(client->new->options[DHO_DHCP_LEASE_TIME].data);
+		    getULong(options[DHO_DHCP_LEASE_TIME].data);
 	else
 		client->new->expiry = DEFAULT_LEASE_TIME;
+
 	/*
 	 * A number that looks negative here is really just very large,
 	 * because the lease expiry offset is unsigned.
@@ -763,16 +796,16 @@ dhcpack(struct in_addr client_addr, struct option_data *options, char *info)
 	 * Take the server-provided renewal time if there is one;
 	 * otherwise figure it out according to the spec.
 	 */
-	if (client->new->options[DHO_DHCP_RENEWAL_TIME].len)
+	if (options[DHO_DHCP_RENEWAL_TIME].len)
 		client->new->renewal =
-		    getULong(client->new->options[DHO_DHCP_RENEWAL_TIME].data);
+		    getULong(options[DHO_DHCP_RENEWAL_TIME].data);
 	else
 		client->new->renewal = client->new->expiry / 2;
 
 	/* Same deal with the rebind time. */
-	if (client->new->options[DHO_DHCP_REBINDING_TIME].len)
+	if (options[DHO_DHCP_REBINDING_TIME].len)
 		client->new->rebind =
-		    getULong(client->new->options[DHO_DHCP_REBINDING_TIME].data);
+		    getULong(options[DHO_DHCP_REBINDING_TIME].data);
 	else
 		client->new->rebind = client->new->renewal +
 		    client->new->renewal / 2 + client->new->renewal / 4;
@@ -790,19 +823,6 @@ dhcpack(struct in_addr client_addr, struct option_data *options, char *info)
 	if (client->new->rebind < cur_time)
 		client->new->rebind = TIME_MAX;
 
-	bind_lease();
-}
-
-void
-bind_lease(void)
-{
-	struct in_addr gateway, mask;
-	struct option_data *options;
-	struct client_lease *lease;
-
-	lease = apply_defaults(client->new);
-	options = lease->options;
-
 	/*
 	 * A duplicate lease once we are responsible & S_RENEWING means we don't
 	 * need to change the interface, routing table or resolv.conf.