Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1520257
| From | "Jason A. Donenfeld" <Jason@zx2c4.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: Source address fib invalidation on IPv6 |
| Date | 2016-11-12 16:50 +0100 |
| Message-ID | <sCIJ3-3SS-3@gated-at.bofh.it> (permalink) |
| References | <sCpQ6-5Y-21@gated-at.bofh.it> <sCsuC-1Y1-37@gated-at.bofh.it> <sCw5c-4hn-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Hi again,
I've done some pretty in depth debugging now to determine exactly what
the behavior of ipv6_stub->ipv6_dst_lookup is. First I'll start with
ip_route_output_flow, which I believe to be well behaved, and then
I'll show ipv6_stub->ipv6_dst_lookup, which seems ill-behaved:
Userspace:
ip addr add 192.168.1.2/24 dev eth0
Kernelspace:
struct flowi4 fl = {
.saddr = 192.168.1.2,
.daddr = 192.168.1.99,
};
rt = ip_route_output_flow(sock_net(sock), &fl, sock);
// rt returns valid rt for routing to 192.168.1.99 from
192.168.1.2 using eth0
Userspace:
ip addr add 192.168.1.3/24 dev eth0
ip addr del 192.168.1.2/24 dev eth0
Kernelspace:
struct flowi4 fl = {
.saddr = 192.168.1.2,
.daddr = 192.168.1.99,
};
rt = ip_route_output_flow(sock_net(sock), &fl, sock);
// PTR_ERR(rt) == -EINVAL
This seems correct behavior to me, since no interface has 192.168.1.2
as a source address.
Now for the incorrect IPv6 behavior:
Userspace:
ip -6 addr add abcd::2/96 dev eth0
Kernelspace:
struct flowi6 fl = {
.saddr = abcd::2,
.daddr = abcd::99,
};
ret = ipv6_stub->ipv6_dst_lookup(sock_net(sock), sock, &dst, &fl);
// ret is 0, and dst is a non-null dst routing to abcd::99 from
abcd::2 using eth0
Userspace:
ip -6 addr add abcd::3/96 dev eth0
ip -6 addr del abcd::2/96 dev eth0
Kernelspace:
struct flowi6 fl = {
.saddr = abcd::2,
.daddr = abcd::99,
};
ret = ipv6_stub->ipv6_dst_lookup(sock_net(sock), sock, &dst, &fl);
// ret is 0, and dst is a non-null dst routing to abcd::99 from
abcd::2 using eth0 **INCORRECT BEHAVIOR!**
This seems *INCORRECT* behavior to me, since no interface has abcd::2
as a source address.
So, to summarize, the problem is that ipv6_dst_lookup will happily
return a dst even though the source IP has been removed from the
interface.
I hope this clarifies things. I await your response.
Regards,
Jason
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Source address fib invalidation on IPv6 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-11-11 20:40 +0100
Re: Source address fib invalidation on IPv6 David Ahern <dsa@cumulusnetworks.com> - 2016-11-11 23:30 +0100
Re: Source address fib invalidation on IPv6 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-11-12 03:20 +0100
Re: Source address fib invalidation on IPv6 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-11-12 16:50 +0100
Re: Source address fib invalidation on IPv6 David Ahern <dsa@cumulusnetworks.com> - 2016-11-12 19:20 +0100
Re: Source address fib invalidation on IPv6 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-11-12 20:10 +0100
Re: Source address fib invalidation on IPv6 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-11-13 01:50 +0100
Re: Source address fib invalidation on IPv6 Hannes Frederic Sowa <hannes@stressinduktion.org> - 2016-11-13 02:00 +0100
Re: Source address fib invalidation on IPv6 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-11-13 02:10 +0100
[PATCH] ip6_output: ensure flow saddr actually belongs to device "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-11-13 14:40 +0100
Re: [PATCH] ip6_output: ensure flow saddr actually belongs to device David Ahern <dsa@cumulusnetworks.com> - 2016-11-13 17:40 +0100
[PATCH v2] ip6_output: ensure flow saddr actually belongs to device "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-11-13 20:10 +0100
Re: [PATCH v2] ip6_output: ensure flow saddr actually belongs to device David Ahern <dsa@cumulusnetworks.com> - 2016-11-13 21:50 +0100
[PATCH v3] ip6_output: ensure flow saddr actually belongs to device "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-11-14 00:30 +0100
Re: [PATCH v3] ip6_output: ensure flow saddr actually belongs to device David Ahern <dsa@cumulusnetworks.com> - 2016-11-14 17:20 +0100
Re: [PATCH v3] ip6_output: ensure flow saddr actually belongs to device Hannes Frederic Sowa <hannes@stressinduktion.org> - 2016-11-14 17:50 +0100
Re: [PATCH v3] ip6_output: ensure flow saddr actually belongs to device David Ahern <dsa@cumulusnetworks.com> - 2016-11-14 18:00 +0100
Re: [PATCH v3] ip6_output: ensure flow saddr actually belongs to device Hannes Frederic Sowa <hannes@stressinduktion.org> - 2016-11-14 18:10 +0100
Re: [PATCH v3] ip6_output: ensure flow saddr actually belongs to device David Ahern <dsa@cumulusnetworks.com> - 2016-11-14 18:20 +0100
Re: [PATCH v3] ip6_output: ensure flow saddr actually belongs to device Hannes Frederic Sowa <hannes@stressinduktion.org> - 2016-11-14 18:40 +0100
Re: [PATCH v3] ip6_output: ensure flow saddr actually belongs to device David Ahern <dsa@cumulusnetworks.com> - 2016-11-14 18:50 +0100
Re: [PATCH v3] ip6_output: ensure flow saddr actually belongs to device Hannes Frederic Sowa <hannes@stressinduktion.org> - 2016-11-14 19:40 +0100
Re: [PATCH v3] ip6_output: ensure flow saddr actually belongs to device "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-11-15 01:50 +0100
Re: [PATCH v3] ip6_output: ensure flow saddr actually belongs to device Hannes Frederic Sowa <hannes@stressinduktion.org> - 2016-11-15 15:50 +0100
Re: [PATCH v3] ip6_output: ensure flow saddr actually belongs to device David Ahern <dsa@cumulusnetworks.com> - 2016-11-15 16:30 +0100
Re: [PATCH] ip6_output: ensure flow saddr actually belongs to device "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-11-13 21:30 +0100
Re: [PATCH] ip6_output: ensure flow saddr actually belongs to device David Ahern <dsa@cumulusnetworks.com> - 2016-11-13 21:40 +0100
Re: Source address fib invalidation on IPv6 "Jason A. Donenfeld" <Jason@zx2c4.com> - 2016-11-13 02:00 +0100
csiph-web