From d7503dcf7cde99b8207569e6152973e52ede52d4 Mon Sep 17 00:00:00 2001
From: krw <krw@openbsd.org>
Date: Wed, 15 Apr 2015 12:40:57 +0000
Subject: [PATCH] Avoid using inet_ntoa() twice in a single printf() parameter
 list by caching the results from excess inet_ntoa() calls before doing the
 printf(). Should improve usefullness (?) of DHCPRELEASE log entries by
 actually printing ciaddr and giaddr correctly when dhcprelays stand between
 servers and clients.

Looks good to dlg@.
---
 usr.sbin/dhcpd/dhcp.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/usr.sbin/dhcpd/dhcp.c b/usr.sbin/dhcpd/dhcp.c
index 0500c7e4d46..9edcd55dda2 100644
--- a/usr.sbin/dhcpd/dhcp.c
+++ b/usr.sbin/dhcpd/dhcp.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dhcp.c,v 1.41 2014/11/11 19:59:47 krw Exp $ */
+/*	$OpenBSD: dhcp.c,v 1.42 2015/04/15 12:40:57 krw Exp $ */
 
 /*
  * Copyright (c) 1995, 1996, 1997, 1998, 1999
@@ -366,6 +366,7 @@ dhcprequest(struct packet *packet)
 void
 dhcprelease(struct packet *packet)
 {
+	char ciaddrbuf[INET_ADDRSTRLEN];
 	struct lease *lease;
 	struct iaddr cip;
 	int i;
@@ -407,8 +408,11 @@ dhcprelease(struct packet *packet)
 		lease = find_lease_by_ip_addr(cip);
 	}
 
+	/* Can't do >1 inet_ntoa() in a printf()! */
+	strlcpy(ciaddrbuf, inet_ntoa(packet->raw->ciaddr), sizeof(ciaddrbuf));
+
 	note("DHCPRELEASE of %s from %s via %s (%sfound)",
-	    inet_ntoa(packet->raw->ciaddr),
+	    ciaddrbuf,
 	    print_hw_addr(packet->raw->htype, packet->raw->hlen,
 	    packet->raw->chaddr),
 	    packet->raw->giaddr.s_addr ? inet_ntoa(packet->raw->giaddr) :
@@ -432,7 +436,7 @@ dhcprelease(struct packet *packet)
 		 */
 		if (!lease->releasing) {
 			note("DHCPRELEASE of %s from %s via %s (found)",
-			    inet_ntoa(packet->raw->ciaddr),
+			    ciaddrbuf,
 			    print_hw_addr(packet->raw->htype,
 			    packet->raw->hlen, packet->raw->chaddr),
 			    packet->raw->giaddr.s_addr ?
@@ -446,7 +450,7 @@ dhcprelease(struct packet *packet)
 		} else {
 			note("DHCPRELEASE of %s from %s via %s ignored "
 			    "(release already pending)",
-			    inet_ntoa(packet->raw->ciaddr),
+			    ciaddrbuf,
 			    print_hw_addr(packet->raw->htype,
 			    packet->raw->hlen, packet->raw->chaddr),
 			    packet->raw->giaddr.s_addr ?
@@ -455,7 +459,7 @@ dhcprelease(struct packet *packet)
 		}
 	} else {
 		note("DHCPRELEASE of %s from %s via %s for nonexistent lease",
-		    inet_ntoa(packet->raw->ciaddr),
+		    ciaddrbuf,
 		    print_hw_addr(packet->raw->htype, packet->raw->hlen,
 		    packet->raw->chaddr),
 		    packet->raw->giaddr.s_addr ?
@@ -1213,6 +1217,7 @@ ack_lease(struct packet *packet, struct lease *lease, unsigned int offer,
 void
 dhcp_reply(struct lease *lease)
 {
+	char ciaddrbuf[INET_ADDRSTRLEN];
 	int bufs = 0, packet_length, i;
 	struct dhcp_packet raw;
 	struct sockaddr_in to;
@@ -1305,10 +1310,13 @@ dhcp_reply(struct lease *lease)
 	raw.hops = state->hops;
 	raw.op = BOOTREPLY;
 
+	/* Can't do >1 inet_ntoa() in a printf()! */
+	strlcpy(ciaddrbuf, inet_ntoa(state->ciaddr), sizeof(ciaddrbuf));
+
 	/* Say what we're doing... */
 	if ((state->offer == DHCPACK) && (lease->flags & INFORM_NOLEASE))
 		note("DHCPACK to %s (%s) via %s",
-		    inet_ntoa(state->ciaddr),
+		    ciaddrbuf,
 		    print_hw_addr(lease->hardware_addr.htype,
 		        lease->hardware_addr.hlen, lease->hardware_addr.haddr),
 		    state->giaddr.s_addr ? inet_ntoa(state->giaddr) :
-- 
2.20.1