Use lease 'epoch' (time lease was acquired) to calculate timers for

renew/rebind/expiry. Treat renew/rebind/expiry statements in leases as
comments for human consumption.

5 files changed, 62 insertions, 86 deletions

diff --git a/sbin/dhclient/clparse.c b/sbin/dhclient/clparse.c
index c21287b3ef0..3655195059a 100644
--- a/sbin/dhclient/clparse.c
+++ b/sbin/dhclient/clparse.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: clparse.c,v 1.149 2017/11/06 13:27:19 krw Exp $	*/
+/*	$OpenBSD: clparse.c,v 1.150 2017/11/09 12:34:25 krw Exp $	*/
 
 /* Parser for dhclient config and lease files. */
 
@@ -588,11 +588,12 @@ parse_client_lease_declaration(FILE *cfile, struct client_lease *lease,
 		    == 0)
 			return;
 		lease->epoch = betoh64(lease->epoch);
+		set_lease_times(lease);
 		break;
 	case TOK_EXPIRE:
-		if (parse_date(cfile, &lease->expiry) == 0)
-			return;
-		break;
+		/* 'expire' is just a comment. See 'epoch'. */
+		skip_to_semi(cfile);
+		return;
 	case TOK_FILENAME:
 		if (parse_string(cfile, NULL, &val) == 0)
 			return;
@@ -618,13 +619,10 @@ parse_client_lease_declaration(FILE *cfile, struct client_lease *lease,
 			return;
 		break;
 	case TOK_REBIND:
-		if (parse_date(cfile, &lease->rebind) == 0)
-			return;
-		break;
 	case TOK_RENEW:
-		if (parse_date(cfile, &lease->renewal) == 0)
-			return;
-		break;
+		/* 'rebind' & 'renew' are just comments. See 'epoch'. */
+		skip_to_semi(cfile);
+		return;
 	case TOK_SERVER_NAME:
 		if (parse_string(cfile, NULL, &val) == 0)
 			return;
diff --git a/sbin/dhclient/dhclient.c b/sbin/dhclient/dhclient.c
index 13e33c5dd52..b74cacf84ff 100644
--- a/sbin/dhclient/dhclient.c
+++ b/sbin/dhclient/dhclient.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dhclient.c,v 1.520 2017/11/06 13:27:19 krw Exp $	*/
+/*	$OpenBSD: dhclient.c,v 1.521 2017/11/09 12:34:25 krw Exp $	*/
 
 /*
  * Copyright 2004 Henning Brauer <henning@openbsd.org>
@@ -144,8 +144,6 @@ struct client_lease *apply_defaults(struct client_lease *);
 struct client_lease *clone_lease(struct client_lease *);
 void		 apply_ignore_list(char *);
 
-void set_lease_times(struct client_lease *);
-
 void state_preboot(struct interface_info *);
 void state_reboot(struct interface_info *);
 void state_init(struct interface_info *);
@@ -1964,6 +1962,12 @@ lease_as_string(char *ifname, char *type, struct client_lease *lease)
 		append_statement(string, sizeof(string), " ", buf);
 	}
 
+	i = asprintf(&buf, "%lld", (long long)lease->epoch);
+	if (i == -1)
+		return NULL;
+	append_statement(string, sizeof(string), "  epoch ", buf);
+	free(buf);
+
 	rslt = strftime(timebuf, sizeof(timebuf), DB_TIMEFMT,
 	    gmtime(&lease->renewal));
 	if (rslt == 0)
@@ -2475,6 +2479,9 @@ set_lease_times(struct client_lease *lease)
 	if (time_max > UINT32_MAX)
 		time_max = UINT32_MAX;
 
+	if (lease->epoch == 0)
+		lease->epoch = cur_time;
+
 	/*
 	 * Take the server-provided times if available.  Otherwise
 	 * figure them out according to the spec.
@@ -2521,9 +2528,9 @@ set_lease_times(struct client_lease *lease)
 		lease->rebind = lease->renewal;
 
 	/* Convert lease lengths to times. */
-	lease->expiry += cur_time;
-	lease->renewal += cur_time;
-	lease->rebind += cur_time;
+	lease->expiry += lease->epoch;
+	lease->renewal += lease->epoch;
+	lease->rebind += lease->epoch;
 }
 
 void
@@ -2612,8 +2619,10 @@ get_recorded_lease(struct interface_info *ifi)
 		if (lp->is_static == 0 && lp->expiry <= cur_time)
 			continue;
 
-		if (lp->is_static != 0)
+		if (lp->is_static != 0) {
+			time(&lp->epoch);
 			set_lease_times(lp);
+		}
 		break;
 	}
 
diff --git a/sbin/dhclient/dhclient.leases.5 b/sbin/dhclient/dhclient.leases.5
index 6412ae5b727..77fbfaa1b2f 100644
--- a/sbin/dhclient/dhclient.leases.5
+++ b/sbin/dhclient/dhclient.leases.5
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: dhclient.leases.5,v 1.11 2017/10/23 13:01:20 krw Exp $
+.\"	$OpenBSD: dhclient.leases.5,v 1.12 2017/11/09 12:34:25 krw Exp $
 .\"
 .\" Copyright (c) 1997 The Internet Software Consortium.
 .\" All rights reserved.
@@ -36,7 +36,7 @@
 .\" see ``http://www.isc.org/isc''.  To learn more about Vixie
 .\" Enterprises, see ``http://www.vix.com''.
 .\"
-.Dd $Mdocdate: October 23 2017 $
+.Dd $Mdocdate: November 9 2017 $
 .Dt DHCLIENT.LEASES 5
 .Os
 .Sh NAME
@@ -77,21 +77,36 @@ is one of:
 The lease was acquired using the
 BOOTP protocol rather than the DHCP protocol.
 .Pp
+.It Ic epoch
+The
+.Xr time 3
+when the lease was obtained.
+This value is used to convert the values of the DHCP options
+.Ic dhcp-lease-time ,
+.Ic dhcp-renewal-time ,
+.Ic dhcp-rebinding-time
+to times.
+A value of 0 will cause
+.Ic epoch
+to be set to the current time when
+.Nm
+is processed.
+.Pp
 .It Ic expire Ar date
 .It Ic rebind Ar date
 .It Ic renew Ar date
 .Ic expire
-defines when
+is when
 .Xr dhclient 8
 will no longer use the lease to configure the interface.
 .Ic rebind
-specifies when
+is when
 .Xr dhclient 8
-begins tring to renew the lease with broadcasts to any server.
+will begin tring to renew the lease with broadcasts to any server.
 .Ic renew
-specifies when
+is when
 .Xr dhclient 8
-begins trying to renew the lease with unicasts to the originating server.
+will begin trying to renew the lease with unicasts to the originating server.
 .Pp
 Dates are specified in accordance with the
 .Xr strptime 3
@@ -103,6 +118,19 @@ For example:
 .Pp
 .Dl renew 1 2017/10/16 14:03:49 UTC
 .Pp
+.Ic expire ,
+.Ic rebind ,
+.Ic renew
+are just comments that are ignored when processing
+.Nm .
+The values used by
+.Xr dhclient 8
+are always recalculated based on
+.Ic epoch
+when
+.Nm
+is processed.
+.Pp
 .It Ic filename Qq Ar string
 The boot filename.
 .Pp
diff --git a/sbin/dhclient/dhcpd.h b/sbin/dhclient/dhcpd.h
index 4a6fa4bb5d7..45ec2525355 100644
--- a/sbin/dhclient/dhcpd.h
+++ b/sbin/dhclient/dhcpd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dhcpd.h,v 1.235 2017/11/06 13:27:19 krw Exp $	*/
+/*	$OpenBSD: dhcpd.h,v 1.236 2017/11/09 12:34:25 krw Exp $	*/
 
 /*
  * Copyright (c) 2004 Henning Brauer <henning@openbsd.org>
@@ -187,7 +187,6 @@ int		 parse_cidr(FILE *, unsigned char *);
 int		 parse_lease_time(FILE *, time_t *);
 int		 parse_decimal(FILE *, unsigned char *, char);
 int		 parse_boolean(FILE *, unsigned char *);
-int		 parse_date(FILE *, time_t *);
 void		 parse_warn(char *);
 
 /* bpf.c */
@@ -224,6 +223,7 @@ void		 dhcpack(struct interface_info *, struct option_data *,char *);
 void		 dhcpnak(struct interface_info *, struct option_data *,char *);
 void		 free_client_lease(struct client_lease *);
 void		 routehandler(struct interface_info *, int);
+void		 set_lease_times(struct client_lease *);
 
 /* packet.c */
 void		 assemble_eh_header(struct ether_addr, struct ether_header *);
diff --git a/sbin/dhclient/parse.c b/sbin/dhclient/parse.c
index a9ea6f86e25..6d597f3709d 100644
--- a/sbin/dhclient/parse.c
+++ b/sbin/dhclient/parse.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: parse.c,v 1.76 2017/11/06 12:51:53 krw Exp $	*/
+/*	$OpenBSD: parse.c,v 1.77 2017/11/09 12:34:25 krw Exp $	*/
 
 /* Common parser code for dhcpd and dhclient. */
 
@@ -337,65 +337,6 @@ parse_decimal(FILE *cfile, unsigned char *buf, char fmt)
 	return 0;
 }
 
-/*
- * date :== NUMBER NUMBER SLASH NUMBER SLASH NUMBER
- *		NUMBER COLON NUMBER COLON NUMBER UTC SEMI
- *
- * Dates are always in UTC; first number is day of week; next is
- * year/month/day; next is hours:minutes:seconds on a 24-hour
- * clock.
- *
- * XXX Will break after year 9999!
- */
-int
-parse_date(FILE *cfile, time_t *date)
-{
-	char		 timestr[23]; /* "wyyyy/mm/ddhh:mm:ssUTC" */
-	struct tm	 tm;
-	char		*val, *p;
-	size_t		 n;
-	time_t		 guess;
-	int		 token;
-
-	memset(timestr, 0, sizeof(timestr));
-
-	n = 0;
-	do {
-		token = peek_token(&val, cfile);
-
-		switch (token) {
-		case EOF:
-			n = sizeof(timestr);
-			break;
-		case';':
-			/* strptime() ignores tm_isdt so ensure it is 0. */
-			memset(&tm, 0, sizeof(tm));
-			p = strptime(timestr, DB_TIMEFMT, &tm);
-			if (p != NULL && *p == '\0') {
-				guess = timegm(&tm);
-				if (guess != -1) {
-					*date = guess;
-					return 1;
-				}
-			}
-			token = next_token(NULL, cfile);
-			break;
-		default:
-			n = strlcat(timestr, val, sizeof(timestr));
-			token = next_token(NULL, cfile);
-			break;
-
-		}
-	} while (n < sizeof(timestr) && token != ';');
-
-	parse_warn("expecting UTC time.");
-
-	if (token != ';')
-		skip_to_semi(cfile);
-
-	return 0;
-}
-
 void
 parse_warn(char *msg)
 {