From: kn <kn@openbsd.org>
Date: Thu, 28 Oct 2021 09:44:49 +0000 (+0000)
Subject: Accept server replies from any server port
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=a1c11753b970f2dc16d85ad9fffac0f76245c3f3;p=openbsd

Accept server replies from any server port

There is no requirement other than replying to client port 68/udp
as per RFC 2131, so drop the 67/udp check.

Same conclusion from florian
Reported and tested by Roc Vallès < vallesroc AT gmail DOT com>, thanks!
---

diff --git a/sbin/dhcpleased/engine.c b/sbin/dhcpleased/engine.c
index 40574ef1aa2..2033ea6ac76 100644
--- a/sbin/dhcpleased/engine.c
+++ b/sbin/dhcpleased/engine.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: engine.c,v 1.27 2021/09/15 15:18:23 florian Exp $	*/
+/*	$OpenBSD: engine.c,v 1.28 2021/10/28 09:44:49 kn Exp $	*/
 
 /*
  * Copyright (c) 2017, 2021 Florian Obser <florian@openbsd.org>
@@ -830,13 +830,6 @@ parse_dhcp(struct dhcpleased_iface *iface, struct imsg_dhcp *dhcp)
 		    ntohs(udp->uh_sport), hbuf_dst, ntohs(udp->uh_dport));
 	}
 
-	if (ntohs(udp->uh_sport) != SERVER_PORT ||
-	    ntohs(udp->uh_dport) != CLIENT_PORT) {
-		log_warnx("%s: invalid ports used %s:%d -> %s:%d", __func__,
-		    hbuf_src, ntohs(udp->uh_sport),
-		    hbuf_dst, ntohs(udp->uh_dport));
-		return;
-	}
 	if (rem < sizeof(*dhcp_hdr))
 		goto too_short;