netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Simon Arlott <simon@fire.lp0.eu>
To: netdev@vger.kernel.org,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	davem@davemloft.net
Cc: stable@kernel.org, yoshfuji@linux-ipv6.org, berni@birkenwald.de,
	linkfanel@yahoo.fr
Subject: "[IPV6]: Fix routing round-robin locking." breaks manual default route (bug 8349)
Date: Mon, 28 May 2007 22:13:04 +0100	[thread overview]
Message-ID: <465B45E0.3040007@simon.arlott.org.uk> (raw)

Initial state - address, no routes:
# ip -6 a
2: eth0: <BROADCAST,MULTICAST,UP,10000> mtu 1500 qlen 1000
    inet6 2001:4b10:1005:0:202:44ff:fe50:91af/64 scope global
       valid_lft forever preferred_lft forever
    inet6 fe80::202:44ff:fe50:91af/64 scope link
       valid_lft forever preferred_lft forever
# ip -6 r
fe80::/64 dev eth0  metric 256  expires 21332290sec mtu 1500 advmss 1440
ff00::/8 dev eth0  metric 256  expires 21332290sec mtu 1500 advmss 1440
unreachable default dev lo  proto none  metric -1  error -101
# ping6 -c 1 2001:4b10:1005:0:205:b4ff:fe12:530
connect: Network is unreachable

Adding a 2000::/3 route works:
# ip -6 r a 2000::/3 via fe80::230:18ff:feb0:25c2 dev eth0
# ping6 -c 1 2001:4b10:1005:0:205:b4ff:fe12:530
64 bytes from 2001:4b10:1005:0:205:b4ff:fe12:530: icmp_seq=1 ttl=64 time=0.921 ms
# ip -6 r d 2000::/3 via fe80::230:18ff:feb0:25c2 dev eth0

Adding a ::/0 route doesn't work:
# ip -6 r a ::/0 via fe80::230:18ff:feb0:25c2 dev eth0
# ping6 -c 1 2001:4b10:1005:0:205:b4ff:fe12:530
connect: Network is unreachable

A route assigned by addrconf works.


Reverting this patch from 2.6.22-rc3 fixes it:
	commit f11e6659ce9058928d73ff440f9b40a818d628ab
	Author: David S. Miller <davem@sunset.davemloft.net>
	Date:   Sat Mar 24 20:36:25 2007 -0700
	    [IPV6]: Fix routing round-robin locking.

This patch is was added to 2.6.20.5, breaking -stable too.


With RT6_DEBUG 3 in route.c (plus some additional debug statements):

Manual default route:
[  535.981000] fib6_add_rt2node
[  535.981000] fib6_add_rt2node fn->fn_flags = 00000007 (RTN_TL_ROOT=00000001)
[  535.981000] fib6_add_rt2node fn->leaf = b0697be0 (ip6_null_entry = b0697be0)
[  535.981000] fib6_add_rt2node rt->rt6i_flags = 00000003 (RTF_DEFAULT = 00010000, RTF_ADDRCONF = 00040000)
[  535.981000] fib6_add_rt2node goto out...
[  535.981000] fib6_add_rt2node out:

Ping6:
[  570.903000] rt6_select(fn->leaf=b1b63140, oif=0)
[  570.903000] find_match rt->rt6i_gateway = 00000000 00000000 00000000 00000000
[  570.903000] find_match m = 10, *mpri = -1
[  570.904000] rt6_select() => b0697be0
[  570.904000] rt6_select(fn->leaf=b1b63140, oif=0)
[  570.904000] find_match rt->rt6i_gateway = 00000000 00000000 00000000 00000000
[  570.904000] find_match m = 10, *mpri = -1
[  570.904000] rt6_select() => b0697be0


Addrconf default route:
[  624.846000] rt6_select(fn->leaf=b1b63300, oif=2)
[  624.846000] find_match rt->rt6i_gateway = 000002ff 00000000 00000000 01000000
[  624.846000] find_match m = 10, *mpri = -1
[  624.846000] rt6_select() => b1b63300
[  624.846000] rt6_select(fn->leaf=b1b63300, oif=2)
[  624.846000] find_match rt->rt6i_gateway = 000002ff 00000000 00000000 01000000
[  624.846000] find_match m = 10, *mpri = -1
[  624.846000] rt6_select() => b1b63300
[  624.846000] fib6_add_rt2node
[  624.846000] fib6_add_rt2node fn->fn_flags = 00000007 (RTN_TL_ROOT=00000001)
[  624.846000] fib6_add_rt2node fn->leaf = b0697be0 (ip6_null_entry = b0697be0)
[  624.846000] fib6_add_rt2node rt->rt6i_flags = 00450003 (RTF_DEFAULT = 00010000, RTF_ADDRCONF = 00040000)
[  624.846000] fib6_add_rt2node out:

Ping6:
[  689.245000] rt6_select(fn->leaf=b1b63140, oif=0)
[  689.245000] find_match rt->rt6i_gateway = 104b0120 00000510 ffb40502 300512fe
[  689.245000] find_match m = 10, *mpri = -1
[  689.245000] rt6_select() => b1b63140
[  689.245000] rt6_select(fn->leaf=b1b63140, oif=0)
[  689.245000] find_match rt->rt6i_gateway = 104b0120 00000510 ffb40502 300512fe
[  689.245000] find_match m = 10, *mpri = -1
[  689.245000] rt6_select() => b1b63140
[  689.248000] rt6_select(fn->leaf=b1b63140, oif=0)
[  689.248000] find_match rt->rt6i_gateway = 104b0120 00000510 ffb40502 300512fe
[  689.248000] find_match m = 10, *mpri = -1
[  689.248000] rt6_select() => b1b63140
[  689.248000] rt6_select(fn->leaf=b1b63140, oif=0)
[  689.248000] find_match rt->rt6i_gateway = 104b0120 00000510 ffb40502 300512fe
[  689.248000] find_match m = 10, *mpri = -1
[  689.248000] rt6_select() => b1b63140
[  689.248000] rt6_select(fn->leaf=b1b63ae0, oif=2)
[  689.248000] find_match rt->rt6i_gateway = 00000000 00000000 00000000 00000000
[  689.248000] find_match m = 9, *mpri = -1
[  689.248000] rt6_select() => b1b63ae0
[  689.702000] rt6_select(fn->leaf=b1b63ae0, oif=2)
[  689.702000] find_match rt->rt6i_gateway = 00000000 00000000 00000000 00000000
[  689.702000] find_match m = 9, *mpri = -1
[  689.702000] rt6_select() => b1b63ae0


Manual 2000::/3 route:
[  765.424000] fib6_add_rt2node
[  765.424000] fib6_add_rt2node fn->fn_flags = 00000000 (RTN_TL_ROOT=00000001)
[  765.424000] fib6_add_rt2node fn->leaf = 00000000 (ip6_null_entry = b0697be0)
[  765.424000] fib6_add_rt2node rt->rt6i_flags = 00000003 (RTF_DEFAULT = 00010000, RTF_ADDRCONF = 00040000)
[  765.424000] fib6_add_rt2node out:
[  765.424000] fib6_add_rt2node fn->fn_flags |= RTN_RTINFO;

Ping6:
[  779.705000] rt6_select(fn->leaf=b1b63060, oif=0)
[  779.705000] find_match rt->rt6i_gateway = 000080fe 00000000 ff183002 c225b0fe
[  779.705000] find_match m = 10, *mpri = -1
[  779.705000] rt6_select() => b1b63060
[  779.713000] rt6_select(fn->leaf=b1b63060, oif=0)
[  779.713000] find_match rt->rt6i_gateway = 000080fe 00000000 ff183002 c225b0fe
[  779.713000] find_match m = 10, *mpri = -1
[  779.713000] rt6_select() => b1b63060
[  779.714000] rt6_select(fn->leaf=b1b63ae0, oif=2)
[  779.714000] find_match rt->rt6i_gateway = 00000000 00000000 00000000 00000000
[  779.714000] find_match m = 9, *mpri = -1
[  779.714000] rt6_select() => b1b63ae0

-- 
Simon Arlott

             reply	other threads:[~2007-05-28 21:13 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-05-28 21:13 Simon Arlott [this message]
2007-06-05 23:36 ` [stable] "[IPV6]: Fix routing round-robin locking." breaks manual default route (bug 8349) Chris Wright
2007-06-05 23:43   ` David Miller

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=465B45E0.3040007@simon.arlott.org.uk \
    --to=simon@fire.lp0.eu \
    --cc=berni@birkenwald.de \
    --cc=davem@davemloft.net \
    --cc=linkfanel@yahoo.fr \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=stable@kernel.org \
    --cc=yoshfuji@linux-ipv6.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).