Date: Thu, 18 Dec 2008 09:48:52 GMT From: KOIE Hidetaka <koie@suri.co.jp> To: freebsd-gnats-submit@FreeBSD.org Subject: kern/129730: respond with wrong ARP. Message-ID: <200812180948.mBI9mqTC054327@www.freebsd.org> Resent-Message-ID: <200812180950.mBI9o1Ou031979@freefall.freebsd.org>
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>Number: 129730
>Category: kern
>Synopsis: respond with wrong ARP.
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Thu Dec 18 09:50:01 UTC 2008
>Closed-Date:
>Last-Modified:
>Originator: KOIE Hidetaka
>Release: current
>Organization:
SURIGIKEN
>Environment:
FreeBSD guriandgura 8.0-CURRENT FreeBSD 8.0-CURRENT #1: Thu Dec 18 17:53:41 JST 2008 koie@guriandgura:/usr/obj/usr/src/sys/GURIANDGURA amd64
>Description:
I built FreeBSD-current at 2008-12-18, and boot it.
Some machine in my network cannot connect a DNS server...
The finding is my FreeBSD machine responds to ARP request for a 3rd machine with a wrong ARP response like this:
6:50:26.320648 00:1b:78:9a:47:db > Broadcast, ethertype ARP (0x0806), length 42: arp who-has 10.1.100.1 tell 10.1.6.59
16:50:26.320784 00:e0:81:74:ef:e4 > 00:1b:78:9a:47:db, ethertype ARP (0x0806), length 60: arp reply 10.1.100.1 is-at 00:1b:78:9a:47:db
16:50:26.320851 00:30:48:99:64:8c > 00:1b:78:9a:47:db, ethertype ARP (0x0806), length 60: arp reply 10.1.100.1 is-at 00:30:48:99:64:8c
# 00:1b:78:9a:47:db is a requester (10.1.6.59).
# 00:e0:81:74:ef:e4 is my machine (10.1.3.67).
# 00:30:48:99:64:8c is a real responder (10.1.100.1).
line 1 is ARP request.
line 2 is ARP response by my machine with wrong.
line 3 is ARP correct response.
note: bridging and proxyall are not specified on my machine.
>How-To-Repeat:
>Fix:
I don't know. (but, a bug may be in r186119).
Now, to suppress the wrong behavior,
Index: if_ether.c
===================================================================
RCS file: /.../.../src/sys/netinet/if_ether.c,v
retrieving revision 1.187
diff -u -p -r1.187 if_ether.c
--- if_ether.c 17 Dec 2008 00:14:28 -0000 1.187
+++ if_ether.c 18 Dec 2008 08:52:44 -0000
@@ -660,6 +660,7 @@ reply:
(void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
(void)memcpy(ar_sha(ah), enaddr, ah->ar_hln);
} else {
+goto drop; /*KOIE*/
if (la == NULL) {
if (!V_arp_proxyall)
goto drop;
>Release-Note:
>Audit-Trail:
>Unformatted:
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