641 Commits

Author SHA1 Message Date
Eric Dumazet
f10ce783bc ipv4: make exception cache less predictible
[ Upstream commit 67d6d681e15b578c1725bad8ad079e05d1c48a8e ]

Even after commit 6457378fe796 ("ipv4: use siphash instead of Jenkins in
fnhe_hashfun()"), an attacker can still use brute force to learn
some secrets from a victim linux host.

One way to defeat these attacks is to make the max depth of the hash
table bucket a random value.

Before this patch, each bucket of the hash table used to store exceptions
could contain 6 items under attack.

After the patch, each bucket would contains a random number of items,
between 6 and 10. The attacker can no longer infer secrets.

This is slightly increasing memory size used by the hash table,
by 50% in average, we do not expect this to be a problem.

This patch is more complex than the prior one (IPv6 equivalent),
because IPv4 was reusing the oldest entry.
Since we need to be able to evict more than one entry per
update_or_create_fnhe() call, I had to replace
fnhe_oldest() with fnhe_remove_oldest().

Also note that we will queue extra kfree_rcu() calls under stress,
which hopefully wont be a too big issue.

Fixes: 4895c771c7f0 ("ipv4: Add FIB nexthop exceptions.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Keyu Man <kman001@ucr.edu>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: David Ahern <dsahern@kernel.org>
Tested-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-22 11:43:02 +02:00
Eric Dumazet
0889f0a3bb inet: use bigger hash table for IP ID generation
commit aa6dd211e4b1dde9d5dc25d699d35f789ae7eeba upstream.

In commit 73f156a6e8c1 ("inetpeer: get rid of ip_id_count")
I used a very small hash table that could be abused
by patient attackers to reveal sensitive information.

Switch to a dynamic sizing, depending on RAM size.

Typical big hosts will now use 128x more storage (2 MB)
to get a similar increase in security and reduction
of hash collisions.

As a bonus, use of alloc_large_system_hash() spreads
allocated memory among all NUMA nodes.

Fixes: 73f156a6e8c1 ("inetpeer: get rid of ip_id_count")
Reported-by: Amit Klein <aksecurity@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-30 08:49:18 -04:00
Vasily Averin
c10bfe7335 rt_cpu_seq_next should increase position index
[ Upstream commit a3ea86739f1bc7e121d921842f0f4a8ab1af94d9 ]

if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.

https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 20:40:04 +02:00
Yuqi Jin
f08aeb334b net: revert "net: get rid of an signed integer overflow in ip_idents_reserve()"
[ Upstream commit a6211caa634da39d861a47437ffcda8b38ef421b ]

Commit adb03115f459 ("net: get rid of an signed integer overflow in ip_idents_reserve()")
used atomic_cmpxchg to replace "atomic_add_return" inside the function
"ip_idents_reserve". The reason was to avoid UBSAN warning.
However, this change has caused performance degrade and in GCC-8,
fno-strict-overflow is now mapped to -fwrapv -fwrapv-pointer
and signed integer overflow is now undefined by default at all
optimization levels[1]. Moreover, it was a bug in UBSAN vs -fwrapv
/-fno-strict-overflow, so Let's revert it safely.

[1] https://gcc.gnu.org/gcc-8/changes.html

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Eric Dumazet <edumazet@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jiong Wang <jiongwang@huawei.com>
Signed-off-by: Yuqi Jin <jinyuqi@huawei.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-03 08:16:24 +02:00
Paolo Abeni
be38a13c9e net: ipv4: really enforce backoff for redirects
[ Upstream commit 57644431a6c2faac5d754ebd35780cf43a531b1a ]

In commit b406472b5ad7 ("net: ipv4: avoid mixed n_redirects and
rate_tokens usage") I missed the fact that a 0 'rate_tokens' will
bypass the backoff algorithm.

Since rate_tokens is cleared after a redirect silence, and never
incremented on redirects, if the host keeps receiving packets
requiring redirect it will reply ignoring the backoff.

Additionally, the 'rate_last' field will be updated with the
cadence of the ingress packet requiring redirect. If that rate is
high enough, that will prevent the host from generating any
other kind of ICMP messages

The check for a zero 'rate_tokens' value was likely a shortcut
to avoid the more complex backoff algorithm after a redirect
silence period. Address the issue checking for 'n_redirects'
instead, which is incremented on successful redirect, and
does not interfere with other ICMP replies.

Fixes: b406472b5ad7 ("net: ipv4: avoid mixed n_redirects and rate_tokens usage")
Reported-and-tested-by: Colin Walters <walters@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20 08:15:39 +02:00
Arnd Bergmann
bcdb7d9ea3 net: ipv4: avoid unused variable warning for sysctl
commit 773daa3caf5d3f87fdb1ab43e9c1b367a38fa394 upstream.

The newly introudced ip_min_valid_pmtu variable is only used when
CONFIG_SYSCTL is set:

net/ipv4/route.c:135:12: error: 'ip_min_valid_pmtu' defined but not used [-Werror=unused-variable]

This moves it to the other variables like it, to avoid the harmless
warning.

Fixes: c7272c2f1229 ("net: ipv4: don't allow setting net.ipv4.route.min_pmtu below 68")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02 17:22:57 +02:00
Sabrina Dubroca
14c137ce30 net: ipv4: don't let PMTU updates increase route MTU
[ Upstream commit 28d35bcdd3925e7293408cdb8aa5f2aac5f0d6e3 ]

When an MTU update with PMTU smaller than net.ipv4.route.min_pmtu is
received, we must clamp its value. However, we can receive a PMTU
exception with PMTU < old_mtu < ip_rt_min_pmtu, which would lead to an
increase in PMTU.

To fix this, take the smallest of the old MTU and ip_rt_min_pmtu.

Before this patch, in case of an update, the exception's MTU would
always change. Now, an exception can have only its lock flag updated,
but not the MTU, so we need to add a check on locking to the following
"is this exception getting updated, or close to expiring?" test.

Fixes: d52e5a7e7ca4 ("ipv4: lock mtu in fnhe when received PMTU < net.ipv4.route.min_pmtu")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-02 17:20:31 +02:00
Stefano Brivio
24bde2946b ipv4: Return -ENETUNREACH if we can't create route but saddr is valid
[ Upstream commit 595e0651d0296bad2491a4a29a7a43eae6328b02 ]

...instead of -EINVAL. An issue was found with older kernel versions
while unplugging a NFS client with pending RPCs, and the wrong error
code here prevented it from recovering once link is back up with a
configured address.

Incidentally, this is not an issue anymore since commit 4f8943f80883
("SUNRPC: Replace direct task wakeups from softirq context"), included
in 5.2-rc7, had the effect of decoupling the forwarding of this error
by using SO_ERROR in xs_wake_error(), as pointed out by Benjamin
Coddington.

To the best of my knowledge, this isn't currently causing any further
issue, but the error code doesn't look appropriate anyway, and we
might hit this in other paths as well.

In detail, as analysed by Gonzalo Siero, once the route is deleted
because the interface is down, and can't be resolved and we return
-EINVAL here, this ends up, courtesy of inet_sk_rebuild_header(),
as the socket error seen by tcp_write_err(), called by
tcp_retransmit_timer().

In turn, tcp_write_err() indirectly calls xs_error_report(), which
wakes up the RPC pending tasks with a status of -EINVAL. This is then
seen by call_status() in the SUN RPC implementation, which aborts the
RPC call calling rpc_exit(), instead of handling this as a
potentially temporary condition, i.e. as a timeout.

Return -EINVAL only if the input parameters passed to
ip_route_output_key_hash_rcu() are actually invalid (this is the case
if the specified source address is multicast, limited broadcast or
all zeroes), but return -ENETUNREACH in all cases where, at the given
moment, the given source address doesn't allow resolving the route.

While at it, drop the initialisation of err to -ENETUNREACH, which
was added to __ip_route_output_key() back then by commit
0315e3827048 ("net: Fix behaviour of unreachable, blackhole and
prohibit routes"), but actually had no effect, as it was, and is,
overwritten by the fib_lookup() return code assignment, and anyway
ignored in all other branches, including the if (fl4->saddr) one:
I find this rather confusing, as it would look like -ENETUNREACH is
the "default" error, while that statement has no effect.

Also note that after commit fc75fc8339e7 ("ipv4: dont create routes
on down devices"), we would get -ENETUNREACH if the device is down,
but -EINVAL if the source address is specified and we can't resolve
the route, and this appears to be rather inconsistent.

Reported-by: Stefan Walter <walteste@inf.ethz.ch>
Analysed-by: Benjamin Coddington <bcodding@redhat.com>
Analysed-by: Gonzalo Siero <gsierohu@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-29 09:15:13 +01:00
Paolo Abeni
a14aed920b net: ipv4: avoid mixed n_redirects and rate_tokens usage
[ Upstream commit b406472b5ad79ede8d10077f0c8f05505ace8b6d ]

Since commit c09551c6ff7f ("net: ipv4: use a dedicated counter
for icmp_v4 redirect packets") we use 'n_redirects' to account
for redirect packets, but we still use 'rate_tokens' to compute
the redirect packets exponential backoff.

If the device sent to the relevant peer any ICMP error packet
after sending a redirect, it will also update 'rate_token' according
to the leaking bucket schema; typically 'rate_token' will raise
above BITS_PER_LONG and the redirect packets backoff algorithm
will produce undefined behavior.

Fix the issue using 'n_redirects' to compute the exponential backoff
in ip_rt_send_redirect().

Note that we still clear rate_tokens after a redirect silence period,
to avoid changing an established behaviour.

The root cause predates git history; before the mentioned commit in
the critical scenario, the kernel stopped sending redirects, after
the mentioned commit the behavior more randomic.

Reported-by: Xiumei Mu <xmu@redhat.com>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Fixes: c09551c6ff7f ("net: ipv4: use a dedicated counter for icmp_v4 redirect packets")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-07 18:53:21 +02:00
Eric Dumazet
b97a2f3d58 inet: switch IP ID generator to siphash
commit df453700e8d81b1bdafdf684365ee2b9431fb702 upstream.

According to Amit Klein and Benny Pinkas, IP ID generation is too weak
and might be used by attackers.

Even with recent net_hash_mix() fix (netns: provide pure entropy for net_hash_mix())
having 64bit key and Jenkins hash is risky.

It is time to switch to siphash and its 128bit keys.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Amit Klein <aksecurity@gmail.com>
Reported-by: Benny Pinkas <benny@pinkas.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-25 10:51:42 +02:00
Eric Dumazet
cd55c74c4e ipv4: add sanity checks in ipv4_link_failure()
[ Upstream commit 20ff83f10f113c88d0bb74589389b05250994c16 ]

Before calling __ip_options_compile(), we need to ensure the network
header is a an IPv4 one, and that it is already pulled in skb->head.

RAW sockets going through a tunnel can end up calling ipv4_link_failure()
with total garbage in the skb, or arbitrary lengthes.

syzbot report :

BUG: KASAN: stack-out-of-bounds in memcpy include/linux/string.h:355 [inline]
BUG: KASAN: stack-out-of-bounds in __ip_options_echo+0x294/0x1120 net/ipv4/ip_options.c:123
Write of size 69 at addr ffff888096abf068 by task syz-executor.4/9204

CPU: 0 PID: 9204 Comm: syz-executor.4 Not tainted 5.1.0-rc5+ #77
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 check_memory_region_inline mm/kasan/generic.c:185 [inline]
 check_memory_region+0x123/0x190 mm/kasan/generic.c:191
 memcpy+0x38/0x50 mm/kasan/common.c:133
 memcpy include/linux/string.h:355 [inline]
 __ip_options_echo+0x294/0x1120 net/ipv4/ip_options.c:123
 __icmp_send+0x725/0x1400 net/ipv4/icmp.c:695
 ipv4_link_failure+0x29f/0x550 net/ipv4/route.c:1204
 dst_link_failure include/net/dst.h:427 [inline]
 vti6_xmit net/ipv6/ip6_vti.c:514 [inline]
 vti6_tnl_xmit+0x10d4/0x1c0c net/ipv6/ip6_vti.c:553
 __netdev_start_xmit include/linux/netdevice.h:4414 [inline]
 netdev_start_xmit include/linux/netdevice.h:4423 [inline]
 xmit_one net/core/dev.c:3292 [inline]
 dev_hard_start_xmit+0x1b2/0x980 net/core/dev.c:3308
 __dev_queue_xmit+0x271d/0x3060 net/core/dev.c:3878
 dev_queue_xmit+0x18/0x20 net/core/dev.c:3911
 neigh_direct_output+0x16/0x20 net/core/neighbour.c:1527
 neigh_output include/net/neighbour.h:508 [inline]
 ip_finish_output2+0x949/0x1740 net/ipv4/ip_output.c:229
 ip_finish_output+0x73c/0xd50 net/ipv4/ip_output.c:317
 NF_HOOK_COND include/linux/netfilter.h:278 [inline]
 ip_output+0x21f/0x670 net/ipv4/ip_output.c:405
 dst_output include/net/dst.h:444 [inline]
 NF_HOOK include/linux/netfilter.h:289 [inline]
 raw_send_hdrinc net/ipv4/raw.c:432 [inline]
 raw_sendmsg+0x1d2b/0x2f20 net/ipv4/raw.c:663
 inet_sendmsg+0x147/0x5d0 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xdd/0x130 net/socket.c:661
 sock_write_iter+0x27c/0x3e0 net/socket.c:988
 call_write_iter include/linux/fs.h:1866 [inline]
 new_sync_write+0x4c7/0x760 fs/read_write.c:474
 __vfs_write+0xe4/0x110 fs/read_write.c:487
 vfs_write+0x20c/0x580 fs/read_write.c:549
 ksys_write+0x14f/0x2d0 fs/read_write.c:599
 __do_sys_write fs/read_write.c:611 [inline]
 __se_sys_write fs/read_write.c:608 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:608
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458c29
Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f293b44bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458c29
RDX: 0000000000000014 RSI: 00000000200002c0 RDI: 0000000000000003
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f293b44c6d4
R13: 00000000004c8623 R14: 00000000004ded68 R15: 00000000ffffffff

The buggy address belongs to the page:
page:ffffea00025aafc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x1fffc0000000000()
raw: 01fffc0000000000 0000000000000000 ffffffff025a0101 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888096abef80: 00 00 00 f2 f2 f2 f2 f2 00 00 00 00 00 00 00 f2
 ffff888096abf000: f2 f2 f2 f2 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888096abf080: 00 00 f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00
                         ^
 ffff888096abf100: 00 00 00 00 f1 f1 f1 f1 00 00 f3 f3 00 00 00 00
 ffff888096abf180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Fixes: ed0de45a1008 ("ipv4: recompile ip options in ipv4_link_failure")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stephen Suryaputra <ssuryaextr@gmail.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-02 09:32:05 +02:00
Eric Dumazet
aec9cfdd09 ipv4: ensure rcu_read_lock() in ipv4_link_failure()
[ Upstream commit c543cb4a5f07e09237ec0fc2c60c9f131b2c79ad ]

fib_compute_spec_dst() needs to be called under rcu protection.

syzbot reported :

WARNING: suspicious RCU usage
5.1.0-rc4+ #165 Not tainted
include/linux/inetdevice.h:220 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
1 lock held by swapper/0/0:
 #0: 0000000051b67925 ((&n->timer)){+.-.}, at: lockdep_copy_map include/linux/lockdep.h:170 [inline]
 #0: 0000000051b67925 ((&n->timer)){+.-.}, at: call_timer_fn+0xda/0x720 kernel/time/timer.c:1315

stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.1.0-rc4+ #165
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 lockdep_rcu_suspicious+0x153/0x15d kernel/locking/lockdep.c:5162
 __in_dev_get_rcu include/linux/inetdevice.h:220 [inline]
 fib_compute_spec_dst+0xbbd/0x1030 net/ipv4/fib_frontend.c:294
 spec_dst_fill net/ipv4/ip_options.c:245 [inline]
 __ip_options_compile+0x15a7/0x1a10 net/ipv4/ip_options.c:343
 ipv4_link_failure+0x172/0x400 net/ipv4/route.c:1195
 dst_link_failure include/net/dst.h:427 [inline]
 arp_error_report+0xd1/0x1c0 net/ipv4/arp.c:297
 neigh_invalidate+0x24b/0x570 net/core/neighbour.c:995
 neigh_timer_handler+0xc35/0xf30 net/core/neighbour.c:1081
 call_timer_fn+0x190/0x720 kernel/time/timer.c:1325
 expire_timers kernel/time/timer.c:1362 [inline]
 __run_timers kernel/time/timer.c:1681 [inline]
 __run_timers kernel/time/timer.c:1649 [inline]
 run_timer_softirq+0x652/0x1700 kernel/time/timer.c:1694
 __do_softirq+0x266/0x95a kernel/softirq.c:293
 invoke_softirq kernel/softirq.c:374 [inline]
 irq_exit+0x180/0x1d0 kernel/softirq.c:414
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0x14a/0x570 arch/x86/kernel/apic/apic.c:1062
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807

Fixes: ed0de45a1008 ("ipv4: recompile ip options in ipv4_link_failure")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Stephen Suryaputra <ssuryaextr@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-27 09:34:41 +02:00
Stephen Suryaputra
ff71f99d5f ipv4: recompile ip options in ipv4_link_failure
[ Upstream commit ed0de45a1008991fdaa27a0152befcb74d126a8b ]

Recompile IP options since IPCB may not be valid anymore when
ipv4_link_failure is called from arp_error_report.

Refer to the commit 3da1ed7ac398 ("net: avoid use IPCB in cipso_v4_error")
and the commit before that (9ef6b42ad6fd) for a similar issue.

Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-27 09:34:41 +02:00
Xin Long
e8273cea4c route: set the deleted fnhe fnhe_daddr to 0 in ip_del_fnhe to fix a race
[ Upstream commit ee60ad219f5c7c4fb2f047f88037770063ef785f ]

The race occurs in __mkroute_output() when 2 threads lookup a dst:

  CPU A                 CPU B
  find_exception()
                        find_exception() [fnhe expires]
                        ip_del_fnhe() [fnhe is deleted]
  rt_bind_exception()

In rt_bind_exception() it will bind a deleted fnhe with the new dst, and
this dst will get no chance to be freed. It causes a dev defcnt leak and
consecutive dmesg warnings:

  unregister_netdevice: waiting for ethX to become free. Usage count = 1

Especially thanks Jon to identify the issue.

This patch fixes it by setting fnhe_daddr to 0 in ip_del_fnhe() to stop
binding the deleted fnhe with a new dst when checking fnhe's fnhe_daddr
and daddr in rt_bind_exception().

It works as both ip_del_fnhe() and rt_bind_exception() are protected by
fnhe_lock and the fhne is freed by kfree_rcu().

Fixes: deed49df7390 ("route: check and remove route cache when we get route")
Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-19 13:14:08 +01:00
Lorenzo Bianconi
575880f2d4 net: ipv4: use a dedicated counter for icmp_v4 redirect packets
[ Upstream commit c09551c6ff7fe16a79a42133bcecba5fc2fc3291 ]

According to the algorithm described in the comment block at the
beginning of ip_rt_send_redirect, the host should try to send
'ip_rt_redirect_number' ICMP redirect packets with an exponential
backoff and then stop sending them at all assuming that the destination
ignores redirects.
If the device has previously sent some ICMP error packets that are
rate-limited (e.g TTL expired) and continues to receive traffic,
the redirect packets will never be transmitted. This happens since
peer->rate_tokens will be typically greater than 'ip_rt_redirect_number'
and so it will never be reset even if the redirect silence timeout
(ip_rt_redirect_silence) has elapsed without receiving any packet
requiring redirects.

Fix it by using a dedicated counter for the number of ICMP redirect
packets that has been sent by the host

I have not been able to identify a given commit that introduced the
issue since ip_rt_send_redirect implements the same rate-limiting
algorithm from commit 1da177e4c3f4 ("Linux-2.6.12-rc2")

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-23 09:05:59 +01:00
Sabrina Dubroca
d543907a47 ipv4: lock mtu in fnhe when received PMTU < net.ipv4.route.min_pmtu
[ Upstream commit d52e5a7e7ca49457dd31fc8b42fb7c0d58a31221 ]

Prior to the rework of PMTU information storage in commit
2c8cec5c10bc ("ipv4: Cache learned PMTU information in inetpeer."),
when a PMTU event advertising a PMTU smaller than
net.ipv4.route.min_pmtu was received, we would disable setting the DF
flag on packets by locking the MTU metric, and set the PMTU to
net.ipv4.route.min_pmtu.

Since then, we don't disable DF, and set PMTU to
net.ipv4.route.min_pmtu, so the intermediate router that has this link
with a small MTU will have to drop the packets.

This patch reestablishes pre-2.6.39 behavior by splitting
rtable->rt_pmtu into a bitfield with rt_mtu_locked and rt_pmtu.
rt_mtu_locked indicates that we shouldn't set the DF bit on that path,
and is checked in ip_dont_fragment().

One possible workaround is to set net.ipv4.route.min_pmtu to a value low
enough to accommodate the lowest MTU encountered.

Fixes: 2c8cec5c10bc ("ipv4: Cache learned PMTU information in inetpeer.")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-30 07:50:36 +02:00
Sabrina Dubroca
06f0188768 net: ipv4: don't allow setting net.ipv4.route.min_pmtu below 68
[ Upstream commit c7272c2f1229125f74f22dcdd59de9bbd804f1c8 ]

According to RFC 1191 sections 3 and 4, ICMP frag-needed messages
indicating an MTU below 68 should be rejected:

    A host MUST never reduce its estimate of the Path MTU below 68
    octets.

and (talking about ICMP frag-needed's Next-Hop MTU field):

    This field will never contain a value less than 68, since every
    router "must be able to forward a datagram of 68 octets without
    fragmentation".

Furthermore, by letting net.ipv4.route.min_pmtu be set to negative
values, we can end up with a very large PMTU when (-1) is cast into u32.

Let's also make ip_rt_min_pmtu a u32, since it's only ever compared to
unsigned ints.

Reported-by: Jianlin Shi <jishi@redhat.com>
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-11 16:21:31 +01:00
Xin Long
007e20bd0f route: update fnhe_expires for redirect when the fnhe exists
[ Upstream commit e39d5246111399dbc6e11cd39fd8580191b86c47 ]

Now when creating fnhe for redirect, it sets fnhe_expires for this
new route cache. But when updating the exist one, it doesn't do it.
It will cause this fnhe never to be expired.

Paolo already noticed it before, in Jianlin's test case, it became
even worse:

When ip route flush cache, the old fnhe is not to be removed, but
only clean it's members. When redirect comes again, this fnhe will
be found and updated, but never be expired due to fnhe_expires not
being set.

So fix it by simply updating fnhe_expires even it's for redirect.

Fixes: aee06da6726d ("ipv4: use seqlock for nh_exceptions")
Reported-by: Jianlin Shi <jishi@redhat.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-14 09:28:22 +01:00
Xin Long
7c4fa0c1c9 route: also update fnhe_genid when updating a route cache
[ Upstream commit cebe84c6190d741045a322f5343f717139993c08 ]

Now when ip route flush cache and it turn out all fnhe_genid != genid.
If a redirect/pmtu icmp packet comes and the old fnhe is found and all
it's members but fnhe_genid will be updated.

Then next time when it looks up route and tries to rebind this fnhe to
the new dst, the fnhe will be flushed due to fnhe_genid != genid. It
causes this redirect/pmtu icmp packet acutally not to be applied.

This patch is to also reset fnhe_genid when updating a route cache.

Fixes: 5aad1de5ea2c ("ipv4: use separate genid for next hop exceptions")
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-14 09:28:22 +01:00
Eric Dumazet
f29c9f46af ipv4: better IP_MAX_MTU enforcement
[ Upstream commit c780a049f9bf442314335372c9abc4548bfe3e44 ]

While working on yet another syzkaller report, I found
that our IP_MAX_MTU enforcements were not properly done.

gcc seems to reload dev->mtu for min(dev->mtu, IP_MAX_MTU), and
final result can be bigger than IP_MAX_MTU :/

This is a problem because device mtu can be changed on other cpus or
threads.

While this patch does not fix the issue I am working on, it is
probably worth addressing it.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-30 10:21:40 +02:00
Eric Dumazet
988b9792b8 ipv4: add reference counting to metrics
[ Upstream commit 3fb07daff8e99243366a081e5129560734de4ada ]

Andrey Konovalov reported crashes in ipv4_mtu()

I could reproduce the issue with KASAN kernels, between
10.246.7.151 and 10.246.7.152 :

1) 20 concurrent netperf -t TCP_RR -H 10.246.7.152 -l 1000 &

2) At the same time run following loop :
while :
do
 ip ro add 10.246.7.152 dev eth0 src 10.246.7.151 mtu 1500
 ip ro del 10.246.7.152 dev eth0 src 10.246.7.151 mtu 1500
done

Cong Wang attempted to add back rt->fi in commit
82486aa6f1b9 ("ipv4: restore rt->fi for reference counting")
but this proved to add some issues that were complex to solve.

Instead, I suggested to add a refcount to the metrics themselves,
being a standalone object (in particular, no reference to other objects)

I tried to make this patch as small as possible to ease its backport,
instead of being super clean. Note that we believe that only ipv4 dst
need to take care of the metric refcount. But if this is wrong,
this patch adds the basic infrastructure to extend this to other
families.

Many thanks to Julian Anastasov for reviewing this patch, and Cong Wang
for his efforts on this problem.

Fixes: 2860583fe840 ("ipv4: Kill rt->fi")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07 12:07:46 +02:00
Florian Larysch
dbaaa5890d net: ipv4: fix multipath RTM_GETROUTE behavior when iif is given
[ Upstream commit a8801799c6975601fd58ae62f48964caec2eb83f ]

inet_rtm_getroute synthesizes a skeletal ICMP skb, which is passed to
ip_route_input when iif is given. If a multipath route is present for
the designated destination, ip_multipath_icmp_hash ends up being called,
which uses the source/destination addresses within the skb to calculate
a hash. However, those are not set in the synthetic skb, causing it to
return an arbitrary and incorrect result.

Instead, use UDP, which gets no such special treatment.

Signed-off-by: Florian Larysch <fl@n621.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-03 08:36:35 -07:00
Julian Anastasov
36931eb015 ipv4: mask tos for input route
[ Upstream commit 6e28099d38c0e50d62c1afc054e37e573adf3d21 ]

Restore the lost masking of TOS in input route code to
allow ip rules to match it properly.

Problem [1] noticed by Shmulik Ladkani <shmulik.ladkani@gmail.com>

[1] http://marc.info/?t=137331755300040&r=1&w=2

Fixes: 89aef8921bfb ("ipv4: Delete routing cache.")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-22 12:43:32 +01:00
David Ahern
958bb1bdc2 net: ipv4: fix table id in getroute response
[ Upstream commit 8a430ed50bb1b19ca14a46661f3b1b35f2fb5c39 ]

rtm_table is an 8-bit field while table ids are allowed up to u32. Commit
709772e6e065 ("net: Fix routing tables with id > 255 for legacy software")
added the preference to set rtm_table in dumps to RT_TABLE_COMPAT if the
table id is > 255. The table id returned on get route requests should do
the same.

Fixes: c36ba6603a11 ("net: Allow user to get table id from route lookup")
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-04 09:47:08 +01:00
David Ahern
a8a213f296 net: ipv4: dst for local input routes should use l3mdev if relevant
[ Upstream commit f5a0aab84b74de68523599817569c057c7ac1622 ]

IPv4 output routes already use l3mdev device instead of loopback for dst's
if it is applicable. Change local input routes to do the same.

This fixes icmp responses for unreachable UDP ports which are directed
to the wrong table after commit 9d1a6c4ea43e4 because local_input
routes use the loopback device. Moving from ingress device to loopback
loses the L3 domain causing responses based on the dst to get to lost.

Fixes: 9d1a6c4ea43e4 ("net: icmp_route_lookup should use rt dev to
		       determine L3 domain")
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-15 13:42:54 +01:00
Stephen Suryaputra Lin
969447f226 ipv4: use new_gw for redirect neigh lookup
In v2.6, ip_rt_redirect() calls arp_bind_neighbour() which returns 0
and then the state of the neigh for the new_gw is checked. If the state
isn't valid then the redirected route is deleted. This behavior is
maintained up to v3.5.7 by check_peer_redirect() because rt->rt_gateway
is assigned to peer->redirect_learned.a4 before calling
ipv4_neigh_lookup().

After commit 5943634fc559 ("ipv4: Maintain redirect and PMTU info in
struct rtable again."), ipv4_neigh_lookup() is performed without the
rt_gateway assigned to the new_gw. In the case when rt_gateway (old_gw)
isn't zero, the function uses it as the key. The neigh is most likely
valid since the old_gw is the one that sends the ICMP redirect message.
Then the new_gw is assigned to fib_nh_exception. The problem is: the
new_gw ARP may never gets resolved and the traffic is blackholed.

So, use the new_gw for neigh lookup.

Changes from v1:
 - use __ipv4_neigh_lookup instead (per Eric Dumazet).

Fixes: 5943634fc559 ("ipv4: Maintain redirect and PMTU info in struct rtable again.")
Signed-off-by: Stephen Suryaputra Lin <ssurya@ieee.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-13 12:24:44 -05:00
David Ahern
6104e112f4 net: ipv4: Do not drop to make_route if oif is l3mdev
Commit e0d56fdd7342 was a bit aggressive removing l3mdev calls in
the IPv4 stack. If the fib_lookup fails we do not want to drop to
make_route if the oif is an l3mdev device.

Also reverts 19664c6a0009 ("net: l3mdev: Remove netif_index_is_l3_master")
which removed netif_index_is_l3_master.

Fixes: e0d56fdd7342 ("net: l3mdev: remove redundant calls")
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-13 12:05:26 -04:00
David S. Miller
b50afd203a Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Three sets of overlapping changes.  Nothing serious.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-02 22:20:41 -04:00
Nikolay Aleksandrov
2cf750704b ipmr, ip6mr: fix scheduling while atomic and a deadlock with ipmr_get_route
Since the commit below the ipmr/ip6mr rtnl_unicast() code uses the portid
instead of the previous dst_pid which was copied from in_skb's portid.
Since the skb is new the portid is 0 at that point so the packets are sent
to the kernel and we get scheduling while atomic or a deadlock (depending
on where it happens) by trying to acquire rtnl two times.
Also since this is RTM_GETROUTE, it can be triggered by a normal user.

Here's the sleeping while atomic trace:
[ 7858.212557] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620
[ 7858.212748] in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/0
[ 7858.212881] 2 locks held by swapper/0/0:
[ 7858.213013]  #0:  (((&mrt->ipmr_expire_timer))){+.-...}, at: [<ffffffff810fbbf5>] call_timer_fn+0x5/0x350
[ 7858.213422]  #1:  (mfc_unres_lock){+.....}, at: [<ffffffff8161e005>] ipmr_expire_process+0x25/0x130
[ 7858.213807] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.8.0-rc7+ #179
[ 7858.213934] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
[ 7858.214108]  0000000000000000 ffff88005b403c50 ffffffff813a7804 0000000000000000
[ 7858.214412]  ffffffff81a1338e ffff88005b403c78 ffffffff810a4a72 ffffffff81a1338e
[ 7858.214716]  000000000000026c 0000000000000000 ffff88005b403ca8 ffffffff810a4b9f
[ 7858.215251] Call Trace:
[ 7858.215412]  <IRQ>  [<ffffffff813a7804>] dump_stack+0x85/0xc1
[ 7858.215662]  [<ffffffff810a4a72>] ___might_sleep+0x192/0x250
[ 7858.215868]  [<ffffffff810a4b9f>] __might_sleep+0x6f/0x100
[ 7858.216072]  [<ffffffff8165bea3>] mutex_lock_nested+0x33/0x4d0
[ 7858.216279]  [<ffffffff815a7a5f>] ? netlink_lookup+0x25f/0x460
[ 7858.216487]  [<ffffffff8157474b>] rtnetlink_rcv+0x1b/0x40
[ 7858.216687]  [<ffffffff815a9a0c>] netlink_unicast+0x19c/0x260
[ 7858.216900]  [<ffffffff81573c70>] rtnl_unicast+0x20/0x30
[ 7858.217128]  [<ffffffff8161cd39>] ipmr_destroy_unres+0xa9/0xf0
[ 7858.217351]  [<ffffffff8161e06f>] ipmr_expire_process+0x8f/0x130
[ 7858.217581]  [<ffffffff8161dfe0>] ? ipmr_net_init+0x180/0x180
[ 7858.217785]  [<ffffffff8161dfe0>] ? ipmr_net_init+0x180/0x180
[ 7858.217990]  [<ffffffff810fbc95>] call_timer_fn+0xa5/0x350
[ 7858.218192]  [<ffffffff810fbbf5>] ? call_timer_fn+0x5/0x350
[ 7858.218415]  [<ffffffff8161dfe0>] ? ipmr_net_init+0x180/0x180
[ 7858.218656]  [<ffffffff810fde10>] run_timer_softirq+0x260/0x640
[ 7858.218865]  [<ffffffff8166379b>] ? __do_softirq+0xbb/0x54f
[ 7858.219068]  [<ffffffff816637c8>] __do_softirq+0xe8/0x54f
[ 7858.219269]  [<ffffffff8107a948>] irq_exit+0xb8/0xc0
[ 7858.219463]  [<ffffffff81663452>] smp_apic_timer_interrupt+0x42/0x50
[ 7858.219678]  [<ffffffff816625bc>] apic_timer_interrupt+0x8c/0xa0
[ 7858.219897]  <EOI>  [<ffffffff81055f16>] ? native_safe_halt+0x6/0x10
[ 7858.220165]  [<ffffffff810d64dd>] ? trace_hardirqs_on+0xd/0x10
[ 7858.220373]  [<ffffffff810298e3>] default_idle+0x23/0x190
[ 7858.220574]  [<ffffffff8102a20f>] arch_cpu_idle+0xf/0x20
[ 7858.220790]  [<ffffffff810c9f8c>] default_idle_call+0x4c/0x60
[ 7858.221016]  [<ffffffff810ca33b>] cpu_startup_entry+0x39b/0x4d0
[ 7858.221257]  [<ffffffff8164f995>] rest_init+0x135/0x140
[ 7858.221469]  [<ffffffff81f83014>] start_kernel+0x50e/0x51b
[ 7858.221670]  [<ffffffff81f82120>] ? early_idt_handler_array+0x120/0x120
[ 7858.221894]  [<ffffffff81f8243f>] x86_64_start_reservations+0x2a/0x2c
[ 7858.222113]  [<ffffffff81f8257c>] x86_64_start_kernel+0x13b/0x14a

Fixes: 2942e9005056 ("[RTNETLINK]: Use rtnl_unicast() for rtnetlink unicasts")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-25 23:41:39 -04:00
David S. Miller
d6989d4bbe Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-09-23 06:46:57 -04:00
Eric Dumazet
adb03115f4 net: get rid of an signed integer overflow in ip_idents_reserve()
Jiri Pirko reported an UBSAN warning happening in ip_idents_reserve()

[] UBSAN: Undefined behaviour in ./arch/x86/include/asm/atomic.h:156:11
[] signed integer overflow:
[] -2117905507 + -695755206 cannot be represented in type 'int'

Since we do not have uatomic_add_return() yet, use atomic_cmpxchg()
so that the arithmetics can be done using unsigned int.

Fixes: 04ca6973f7c1 ("ip: make IP identifiers less predictable")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-22 02:41:17 -04:00
David Ahern
e0d56fdd73 net: l3mdev: remove redundant calls
A previous patch added l3mdev flow update making these hooks
redundant. Remove them.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-10 23:12:52 -07:00
David Ahern
ebfc102c56 net: vrf: Flip IPv4 output path from FIB lookup hook to out hook
Flip the IPv4 output path to use the l3mdev tx out hook. The VRF dst
is not returned on the first FIB lookup. Instead, the dst on the
skb is switched at the beginning of the IPv4 output processing to
send the packet to the VRF driver on xmit.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-10 23:12:52 -07:00
David Ahern
5f02ce24c2 net: l3mdev: Allow the l3mdev to be a loopback
Allow an L3 master device to act as the loopback for that L3 domain.
For IPv4 the device can also have the address 127.0.0.1.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-10 23:12:52 -07:00
Roopa Prabhu
14972cbd34 net: lwtunnel: Handle fragmentation
Today mpls iptunnel lwtunnel_output redirect expects the tunnel
output function to handle fragmentation. This is ok but can be
avoided if we did not do the mpls output redirect too early.
ie we could wait until ip fragmentation is done and then call
mpls output for each ip fragment.

To make this work we will need,
1) the lwtunnel state to carry encap headroom
2) and do the redirect to the encap output handler on the ip fragment
(essentially do the output redirect after fragmentation)

This patch adds tunnel headroom in lwtstate to make sure we
account for tunnel data in mtu calculations during fragmentation
and adds new xmit redirect handler to redirect to lwtunnel xmit func
after ip fragmentation.

This includes IPV6 and some mtu fixes and testing from David Ahern.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-30 22:27:18 -07:00
David Ahern
1ff23beebd net: l3mdev: Allow send on enslaved interface
Allow udp and raw sockets to send by oif that is an enslaved interface
versus the l3mdev/VRF device. For example, this allows BFD to use ifindex
from IP_PKTINFO on a receive to send a response without the need to
convert to the VRF index. It also allows ping and ping6 to work when
specifying an enslaved interface (e.g., ping -I swp1 <ip>) which is
a natural use case.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-09 22:33:52 -04:00
Eric Dumazet
b45386efa2 net: rename IP_INC_STATS_BH()
Rename IP_INC_STATS_BH() to __IP_INC_STATS(), to
better express this is used in non preemptible context.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-27 22:48:23 -04:00
Chris Friesen
d6d5e999e5 route: do not cache fib route info on local routes with oif
For local routes that require a particular output interface we do not want
to cache the result.  Caching the result causes incorrect behaviour when
there are multiple source addresses on the interface.  The end result
being that if the intended recipient is waiting on that interface for the
packet he won't receive it because it will be delivered on the loopback
interface and the IP_PKTINFO ipi_ifindex will be set to the loopback
interface as well.

This can be tested by running a program such as "dhcp_release" which
attempts to inject a packet on a particular interface so that it is
received by another program on the same board.  The receiving process
should see an IP_PKTINFO ipi_ifndex value of the source interface
(e.g., eth1) instead of the loopback interface (e.g., lo).  The packet
will still appear on the loopback interface in tcpdump but the important
aspect is that the CMSG info is correct.

Sample dhcp_release command line:

   dhcp_release eth1 192.168.204.222 02:11:33:22:44:66

Signed-off-by: Allain Legacy <allain.legacy@windriver.com>
Signed off-by: Chris Friesen <chris.friesen@windriver.com>
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-13 23:33:01 -04:00
David Ahern
9ab179d83b net: vrf: Fix dst reference counting
Vivek reported a kernel exception deleting a VRF with an active
connection through it. The root cause is that the socket has a cached
reference to a dst that is destroyed. Converting the dst_destroy to
dst_release and letting proper reference counting kick in does not
work as the dst has a reference to the device which needs to be released
as well.

I talked to Hannes about this at netdev and he pointed out the ipv4 and
ipv6 dst handling has dst_ifdown for just this scenario. Rather than
continuing with the reinvented dst wheel in VRF just remove it and
leverage the ipv4 and ipv6 versions.

Fixes: 193125dbd8eb2 ("net: Introduce VRF device driver")
Fixes: 35402e3136634 ("net: Add IPv6 support to VRF device")

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-11 15:56:20 -04:00
Xin Long
deed49df73 route: check and remove route cache when we get route
Since the gc of ipv4 route was removed, the route cached would has
no chance to be removed, and even it has been timeout, it still could
be used, cause no code to check it's expires.

Fix this issue by checking  and removing route cache when we get route.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-18 11:31:36 -05:00
David Ahern
28335a7445 net: Do not drop to make_route if oif is l3mdev
Commit deaa0a6a930 ("net: Lookup actual route when oif is VRF device")
exposed a bug in __ip_route_output_key_hash for VRF devices: on FIB lookup
failure if the oif is specified the current logic drops to make_route on
the assumption that the route tables are wrong. For VRF/L3 master devices
this leads to wrong dst entries and route lookups. For example:
    $ ip route ls table vrf-red
    unreachable default
    broadcast 10.2.1.0 dev eth1  proto kernel  scope link  src 10.2.1.2
    10.2.1.0/24 dev eth1  proto kernel  scope link  src 10.2.1.2
    local 10.2.1.2 dev eth1  proto kernel  scope host  src 10.2.1.2
    broadcast 10.2.1.255 dev eth1  proto kernel  scope link  src 10.2.1.2

    $ ip route get oif vrf-red 1.1.1.1
    1.1.1.1 dev vrf-red  src 10.0.0.2
        cache

With this patch:
    $  ip route get oif vrf-red 1.1.1.1
    RTNETLINK answers: No route to host

which is the correct response based on the default route

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-08 05:18:47 -07:00
Eric W. Biederman
ede2059dba dst: Pass net into dst->output
The network namespace is already passed into dst_output pass it into
dst->output lwt->output and friends.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-08 04:27:03 -07:00
Eric W. Biederman
b92dacd456 ipv4: Merge __ip_local_out and __ip_local_out_sk
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-08 04:26:57 -07:00
Eric W. Biederman
4ebdfba73c dst: Pass a sk into .local_out
For consistency with the other similar methods in the kernel pass a
struct sock into the dst_ops .local_out method.

Simplifying the socket passing case is needed a prequel to passing a
struct net reference into .local_out.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-08 04:26:55 -07:00
David Ahern
deaa0a6a93 net: Lookup actual route when oif is VRF device
If the user specifies a VRF device in a get route query the custom route
pointing to the VRF device is returned:

    $ ip route ls table vrf-red
    unreachable default
    broadcast 10.2.1.0 dev eth1  proto kernel  scope link  src 10.2.1.2
    10.2.1.0/24 dev eth1  proto kernel  scope link  src 10.2.1.2
    local 10.2.1.2 dev eth1  proto kernel  scope host  src 10.2.1.2
    broadcast 10.2.1.255 dev eth1  proto kernel  scope link  src 10.2.1.2

    $ ip route get oif vrf-red 10.2.1.40
    10.2.1.40 dev vrf-red
        cache

Add the flags to skip the custom route and go directly to the FIB. With
this patch the actual route is returned:

    $ ip route get oif vrf-red 10.2.1.40
    10.2.1.40 dev eth1  src 10.2.1.2
        cache

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-07 04:31:16 -07:00
David Ahern
3ce58d8435 net: Refactor path selection in __ip_route_output_key_hash
VRF device needs the same path selection following lookup to set source
address. Rather than duplicating code, move existing code into a
function that is exported to modules.

Code move only; no functional change.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-07 04:27:44 -07:00
Peter Nørlund
79a131592d ipv4: ICMP packet inspection for multipath
ICMP packets are inspected to let them route together with the flow they
belong to, minimizing the chance that a problematic path will affect flows
on other paths, and so that anycast environments can work with ECMP.

Signed-off-by: Peter Nørlund <pch@ordbogen.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-05 03:00:04 -07:00
Peter Nørlund
0e884c78ee ipv4: L3 hash-based multipath
Replaces the per-packet multipath with a hash-based multipath using
source and destination address.

Signed-off-by: Peter Nørlund <pch@ordbogen.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-05 02:59:21 -07:00
David S. Miller
f6d3125fa3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	net/dsa/slave.c

net/dsa/slave.c simply had overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-02 07:21:25 -07:00
David Ahern
b84f787820 net: Initialize flow flags in input path
The fib_table_lookup tracepoint found 2 places where the flowi4_flags is
not initialized.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29 21:52:32 -07:00