Commit Graph

1402 Commits

Author SHA1 Message Date
Liping Zhang
d1a6cba576 netfilter: nft_chain_route: re-route before skb is queued to userspace
Imagine such situation, user add the following nft rules, and queue
the packets to userspace for further check:
  # ip rule add fwmark 0x0/0x1 lookup eth0
  # ip rule add fwmark 0x1/0x1 lookup eth1
  # nft add table filter
  # nft add chain filter output {type route hook output priority 0 \;}
  # nft add rule filter output mark set 0x1
  # nft add rule filter output queue num 0

But after we reinject the skbuff, the packet will be sent via the
wrong route, i.e. in this case, the packet will be routed via eth0
table, not eth1 table. Because we skip to do re-route when verdict
is NF_QUEUE, even if the mark was changed.

Acctually, we should not touch sk_buff if verdict is NF_DROP or
NF_STOLEN, and when re-route fails, return NF_DROP with error code.
This is consistent with the mangle table in iptables.

Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-09-06 18:02:37 +02:00
Liping Zhang
89e1f6d2b9 netfilter: nft_reject: restrict to INPUT/FORWARD/OUTPUT
After I add the nft rule "nft add rule filter prerouting reject
with tcp reset", kernel panic happened on my system:
  NULL pointer dereference at ...
  IP: [<ffffffff81b9db2f>] nf_send_reset+0xaf/0x400
  Call Trace:
  [<ffffffff81b9da80>] ? nf_reject_ip_tcphdr_get+0x160/0x160
  [<ffffffffa0928061>] nft_reject_ipv4_eval+0x61/0xb0 [nft_reject_ipv4]
  [<ffffffffa08e836a>] nft_do_chain+0x1fa/0x890 [nf_tables]
  [<ffffffffa08e8170>] ? __nft_trace_packet+0x170/0x170 [nf_tables]
  [<ffffffffa06e0900>] ? nf_ct_invert_tuple+0xb0/0xc0 [nf_conntrack]
  [<ffffffffa07224d4>] ? nf_nat_setup_info+0x5d4/0x650 [nf_nat]
  [...]

Because in the PREROUTING chain, routing information is not exist,
then we will dereference the NULL pointer and oops happen.

So we restrict reject expression to INPUT, FORWARD and OUTPUT chain.
This is consistent with iptables REJECT target.

Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-08-25 12:55:34 +02:00
Florian Westphal
f4dc77713f netfilter: x_tables: speed up jump target validation
The dummy ruleset I used to test the original validation change was broken,
most rules were unreachable and were not tested by mark_source_chains().

In some cases rulesets that used to load in a few seconds now require
several minutes.

sample ruleset that shows the behaviour:

echo "*filter"
for i in $(seq 0 100000);do
        printf ":chain_%06x - [0:0]\n" $i
done
for i in $(seq 0 100000);do
   printf -- "-A INPUT -j chain_%06x\n" $i
   printf -- "-A INPUT -j chain_%06x\n" $i
   printf -- "-A INPUT -j chain_%06x\n" $i
done
echo COMMIT

[ pipe result into iptables-restore ]

This ruleset will be about 74mbyte in size, with ~500k searches
though all 500k[1] rule entries. iptables-restore will take forever
(gave up after 10 minutes)

Instead of always searching the entire blob for a match, fill an
array with the start offsets of every single ipt_entry struct,
then do a binary search to check if the jump target is present or not.

After this change ruleset restore times get again close to what one
gets when reverting 3647234101 (~3 seconds on my workstation).

[1] every user-defined rule gets an implicit RETURN, so we get
300k jumps + 100k userchains + 100k returns -> 500k rule entries

Fixes: 3647234101 ("netfilter: x_tables: validate targets of jumps")
Reported-by: Jeff Wu <wujiafu@gmail.com>
Tested-by: Jeff Wu <wujiafu@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-18 21:35:23 +02:00
Liping Zhang
64b87639c9 netfilter: conntrack: fix race between nf_conntrack proc read and hash resize
When we do "cat /proc/net/nf_conntrack", and meanwhile resize the conntrack
hash table via /sys/module/nf_conntrack/parameters/hashsize, race will
happen, because reader can observe a newly allocated hash but the old size
(or vice versa). So oops will happen like follows:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000017
  IP: [<ffffffffa0418e21>] seq_print_acct+0x11/0x50 [nf_conntrack]
  Call Trace:
  [<ffffffffa0412f4e>] ? ct_seq_show+0x14e/0x340 [nf_conntrack]
  [<ffffffff81261a1c>] seq_read+0x2cc/0x390
  [<ffffffff812a8d62>] proc_reg_read+0x42/0x70
  [<ffffffff8123bee7>] __vfs_read+0x37/0x130
  [<ffffffff81347980>] ? security_file_permission+0xa0/0xc0
  [<ffffffff8123cf75>] vfs_read+0x95/0x140
  [<ffffffff8123e475>] SyS_read+0x55/0xc0
  [<ffffffff817c2572>] entry_SYSCALL_64_fastpath+0x1a/0xa4

It is very easy to reproduce this kernel crash.
1. open one shell and input the following cmds:
  while : ; do
    echo $RANDOM > /sys/module/nf_conntrack/parameters/hashsize
  done
2. open more shells and input the following cmds:
  while : ; do
    cat /proc/net/nf_conntrack
  done
3. just wait a monent, oops will happen soon.

The solution in this patch is based on Florian's Commit 5e3c61f981
("netfilter: conntrack: fix lookup race during hash resize"). And
add a wrapper function nf_conntrack_get_ht to get hash and hsize
suggested by Florian Westphal.

Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-11 11:38:57 +02:00
Joe Perches
c37a2dfa67 netfilter: Convert FWINV<[foo]> macros and uses to NF_INVF
netfilter uses multiple FWINV #defines with identical form that hide a
specific structure variable and dereference it with a invflags member.

$ git grep "#define FWINV"
include/linux/netfilter_bridge/ebtables.h:#define FWINV(bool,invflg) ((bool) ^ !!(info->invflags & invflg))
net/bridge/netfilter/ebtables.c:#define FWINV2(bool, invflg) ((bool) ^ !!(e->invflags & invflg))
net/ipv4/netfilter/arp_tables.c:#define FWINV(bool, invflg) ((bool) ^ !!(arpinfo->invflags & (invflg)))
net/ipv4/netfilter/ip_tables.c:#define FWINV(bool, invflg) ((bool) ^ !!(ipinfo->invflags & (invflg)))
net/ipv6/netfilter/ip6_tables.c:#define FWINV(bool, invflg) ((bool) ^ !!(ip6info->invflags & (invflg)))
net/netfilter/xt_tcpudp.c:#define FWINVTCP(bool, invflg) ((bool) ^ !!(tcpinfo->invflags & (invflg)))

Consolidate these macros into a single NF_INVF macro.

Miscellanea:

o Neaten the alignment around these uses
o A few lines are > 80 columns for intelligibility

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-03 10:55:07 +02:00
Pablo Neira Ayuso
468b021b94 netfilter: x_tables: simplify ip{6}table_mangle_hook()
No need for a special case to handle NF_INET_POST_ROUTING, this is
basically the same handling as for prerouting, input, forward.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-01 16:37:02 +02:00
Liping Zhang
e1dbbc5907 netfilter: nf_reject_ipv4: don't send tcp RST if the packet is non-TCP
In iptables, if the user add a rule to send tcp RST and specify the
non-TCP protocol, such as UDP, kernel will reject this request. But
in nftables, this validity check only occurs in nft tool, i.e. only
in userspace.

This means that user can add such a rule like follows via nfnetlink:
  "nft add rule filter forward ip protocol udp reject with tcp reset"

This will generate some confusing tcp RST packets. So we should send
tcp RST only when it is TCP packet.

Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-24 11:03:22 +02:00
Florian Westphal
0a93aaedc4 netfilter: conntrack: use a single expectation table for all namespaces
We already include netns address in the hash and compare the netns pointers
during lookup, so even if namespaces have overlapping addresses entries
will be spread across the expectation table.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-06 11:50:01 +02:00
Florian Westphal
03d7dc5cdf netfilter: conntrack: check netns when walking expect hash
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-06 11:50:01 +02:00
Pablo Neira Ayuso
d7cdf81657 netfilter: x_tables: get rid of old and inconsistent debugging
The dprintf() and duprintf() functions are enabled at compile time,
these days we have better runtime debugging through pr_debug() and
static keys.

On top of this, this debugging is so old that I don't expect anyone
using this anymore, so let's get rid of this.

IP_NF_ASSERT() is still left in place, although this needs that
NETFILTER_DEBUG is enabled, I think these assertions provide useful
context information when reading the code.

Note that ARP_NF_ASSERT() has been removed as there is no user of
this.

Kill also DEBUG_ALLOW_ALL and a couple of pr_error() and pr_debug()
spots that are inconsistently placed in the code.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05 16:39:51 +02:00
Florian Westphal
56d52d4892 netfilter: conntrack: use a single hashtable for all namespaces
We already include netns address in the hash and compare the netns pointers
during lookup, so even if namespaces have overlapping addresses entries
will be spread across the table.

Assuming 64k bucket size, this change saves 0.5 mbyte per namespace on a
64bit system.

NAT bysrc and expectation hash is still per namespace, those will
changed too soon.

Future patch will also make conntrack object slab cache global again.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05 16:39:47 +02:00
Florian Westphal
e0c7d47221 netfilter: conntrack: check netns when comparing conntrack objects
Once we place all conntracks in the same hash table we must also compare
the netns pointer to skip conntracks that belong to a different namespace.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05 16:39:46 +02:00
Florian Westphal
245cfdcaba netfilter: conntrack: small refactoring of conntrack seq_printf
The iteration process is lockless, so we test if the conntrack object is
eligible for printing (e.g. is AF_INET) after obtaining the reference
count.

Once we put all conntracks into same hash table we might see more
entries that need to be skipped.

So add a helper and first perform the test in a lockless fashion
for fast skip.

Once we obtain the reference count, just repeat the check.

Note that this refactoring also includes a missing check for unconfirmed
conntrack entries due to slab rcu object re-usage, so they need to be
skipped since they are not part of the listing.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-05 16:39:45 +02:00
Pablo Neira Ayuso
92b4423e3a netfilter: fix IS_ERR_VALUE usage
This is a forward-port of the original patch from Andrzej Hajda,
he said:

"IS_ERR_VALUE should be used only with unsigned long type.
Otherwise it can work incorrectly. To achieve this function
xt_percpu_counter_alloc is modified to return unsigned long,
and its result is assigned to temporary variable to perform
error checking, before assigning to .pcnt field.

The patch follows conclusion from discussion on LKML [1][2].

[1]: http://permalink.gmane.org/gmane.linux.kernel/2120927
[2]: http://permalink.gmane.org/gmane.linux.kernel/2150581"

Original patch from Andrzej is here:

http://patchwork.ozlabs.org/patch/582970/

This patch has clashed with input validation fixes for x_tables.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-29 11:02:33 +02:00
David S. Miller
11afbff861 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

The following patchset contains Netfilter updates for your net-next
tree, mostly from Florian Westphal to sort out the lack of sufficient
validation in x_tables and connlabel preparation patches to add
nf_tables support. They are:

1) Ensure we don't go over the ruleset blob boundaries in
   mark_source_chains().

2) Validate that target jumps land on an existing xt_entry. This extra
   sanitization comes with a performance penalty when loading the ruleset.

3) Introduce xt_check_entry_offsets() and use it from {arp,ip,ip6}tables.

4) Get rid of the smallish check_entry() functions in {arp,ip,ip6}tables.

5) Make sure the minimal possible target size in x_tables.

6) Similar to #3, add xt_compat_check_entry_offsets() for compat code.

7) Check that standard target size is valid.

8) More sanitization to ensure that the target_offset field is correct.

9) Add xt_check_entry_match() to validate that matches are well-formed.

10-12) Three patch to reduce the number of parameters in
    translate_compat_table() for {arp,ip,ip6}tables by using a container
    structure.

13) No need to return value from xt_compat_match_from_user(), so make
    it void.

14) Consolidate translate_table() so it can be used by compat code too.

15) Remove obsolete check for compat code, so we keep consistent with
    what was already removed in the native layout code (back in 2007).

16) Get rid of target jump validation from mark_source_chains(),
    obsoleted by #2.

17) Introduce xt_copy_counters_from_user() to consolidate counter
    copying, and use it from {arp,ip,ip6}tables.

18,22) Get rid of unnecessary explicit inlining in ctnetlink for dump
    functions.

19) Move nf_connlabel_match() to xt_connlabel.

20) Skip event notification if connlabel did not change.

21) Update of nf_connlabels_get() to make the upcoming nft connlabel
    support easier.

23) Remove spinlock to read protocol state field in conntrack.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-24 00:12:08 -04:00
Florian Westphal
d7591f0c41 netfilter: x_tables: introduce and use xt_copy_counters_from_user
The three variants use same copy&pasted code, condense this into a
helper and use that.

Make sure info.name is 0-terminated.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-14 00:30:41 +02:00
Florian Westphal
aded9f3e9f netfilter: x_tables: remove obsolete check
Since 'netfilter: x_tables: validate targets of jumps' change we
validate that the target aligns exactly with beginning of a rule,
so offset test is now redundant.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-14 00:30:41 +02:00
Florian Westphal
95609155d7 netfilter: x_tables: remove obsolete overflow check for compat case too
commit 9e67d5a739
("[NETFILTER]: x_tables: remove obsolete overflow check") left the
compat parts alone, but we can kill it there as well.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-14 00:30:40 +02:00
Florian Westphal
09d9686047 netfilter: x_tables: do compat validation via translate_table
This looks like refactoring, but its also a bug fix.

Problem is that the compat path (32bit iptables, 64bit kernel) lacks a few
sanity tests that are done in the normal path.

For example, we do not check for underflows and the base chain policies.

While its possible to also add such checks to the compat path, its more
copy&pastry, for instance we cannot reuse check_underflow() helper as
e->target_offset differs in the compat case.

Other problem is that it makes auditing for validation errors harder; two
places need to be checked and kept in sync.

At a high level 32 bit compat works like this:
1- initial pass over blob:
   validate match/entry offsets, bounds checking
   lookup all matches and targets
   do bookkeeping wrt. size delta of 32/64bit structures
   assign match/target.u.kernel pointer (points at kernel
   implementation, needed to access ->compatsize etc.)

2- allocate memory according to the total bookkeeping size to
   contain the translated ruleset

3- second pass over original blob:
   for each entry, copy the 32bit representation to the newly allocated
   memory.  This also does any special match translations (e.g.
   adjust 32bit to 64bit longs, etc).

4- check if ruleset is free of loops (chase all jumps)

5-first pass over translated blob:
   call the checkentry function of all matches and targets.

The alternative implemented by this patch is to drop steps 3&4 from the
compat process, the translation is changed into an intermediate step
rather than a full 1:1 translate_table replacement.

In the 2nd pass (step #3), change the 64bit ruleset back to a kernel
representation, i.e. put() the kernel pointer and restore ->u.user.name .

This gets us a 64bit ruleset that is in the format generated by a 64bit
iptables userspace -- we can then use translate_table() to get the
'native' sanity checks.

This has two drawbacks:

1. we re-validate all the match and target entry structure sizes even
though compat translation is supposed to never generate bogus offsets.
2. we put and then re-lookup each match and target.

THe upside is that we get all sanity tests and ruleset validations
provided by the normal path and can remove some duplicated compat code.

iptables-restore time of autogenerated ruleset with 300k chains of form
-A CHAIN0001 -m limit --limit 1/s -j CHAIN0002
-A CHAIN0002 -m limit --limit 1/s -j CHAIN0003

shows no noticeable differences in restore times:
old:   0m30.796s
new:   0m31.521s
64bit: 0m25.674s

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-14 00:30:40 +02:00
Florian Westphal
0188346f21 netfilter: x_tables: xt_compat_match_from_user doesn't need a retval
Always returned 0.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-14 00:30:40 +02:00
Florian Westphal
8dddd32756 netfilter: arp_tables: simplify translate_compat_table args
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-14 00:30:39 +02:00
Florian Westphal
7d3f843eed netfilter: ip_tables: simplify translate_compat_table args
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-14 00:30:38 +02:00
Florian Westphal
ce683e5f9d netfilter: x_tables: check for bogus target offset
We're currently asserting that targetoff + targetsize <= nextoff.

Extend it to also check that targetoff is >= sizeof(xt_entry).
Since this is generic code, add an argument pointing to the start of the
match/target, we can then derive the base structure size from the delta.

We also need the e->elems pointer in a followup change to validate matches.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-14 00:30:37 +02:00
Florian Westphal
fc1221b3a1 netfilter: x_tables: add compat version of xt_check_entry_offsets
32bit rulesets have different layout and alignment requirements, so once
more integrity checks get added to xt_check_entry_offsets it will reject
well-formed 32bit rulesets.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-14 00:30:36 +02:00
Florian Westphal
aa412ba225 netfilter: x_tables: kill check_entry helper
Once we add more sanity testing to xt_check_entry_offsets it
becomes relvant if we're expecting a 32bit 'config_compat' blob
or a normal one.

Since we already have a lot of similar-named functions (check_entry,
compat_check_entry, find_and_check_entry, etc.) and the current
incarnation is short just fold its contents into the callers.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-14 00:30:36 +02:00
Florian Westphal
7d35812c32 netfilter: x_tables: add and use xt_check_entry_offsets
Currently arp/ip and ip6tables each implement a short helper to check that
the target offset is large enough to hold one xt_entry_target struct and
that t->u.target_size fits within the current rule.

Unfortunately these checks are not sufficient.

To avoid adding new tests to all of ip/ip6/arptables move the current
checks into a helper, then extend this helper in followup patches.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-14 00:30:35 +02:00
Florian Westphal
3647234101 netfilter: x_tables: validate targets of jumps
When we see a jump also check that the offset gets us to beginning of
a rule (an ipt_entry).

The extra overhead is negible, even with absurd cases.

300k custom rules, 300k jumps to 'next' user chain:
[ plus one jump from INPUT to first userchain ]:

Before:
real    0m24.874s
user    0m7.532s
sys     0m16.076s

After:
real    0m27.464s
user    0m7.436s
sys     0m18.840s

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-14 00:30:35 +02:00
Florian Westphal
f24e230d25 netfilter: x_tables: don't move to non-existent next rule
Ben Hawkes says:

 In the mark_source_chains function (net/ipv4/netfilter/ip_tables.c) it
 is possible for a user-supplied ipt_entry structure to have a large
 next_offset field. This field is not bounds checked prior to writing a
 counter value at the supplied offset.

Base chains enforce absolute verdict.

User defined chains are supposed to end with an unconditional return,
xtables userspace adds them automatically.

But if such return is missing we will move to non-existent next rule.

Reported-by: Ben Hawkes <hawkes@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-14 00:30:34 +02:00
Florian Westphal
ff76def3bd netfilter: arp_tables: register table in initns
arptables is broken since we didn't register the table anymore --
even 'arptables -L' fails.

Fixes: b9e69e1273 ("netfilter: xtables: don't hook tables by default")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-07 11:58:49 +02:00
Liping Zhang
29421198c3 netfilter: ipv4: fix NULL dereference
Commit fa50d974d1 ("ipv4: Namespaceify ip_default_ttl sysctl knob")
use sock_net(skb->sk) to get the net namespace, but we can't assume
that sk_buff->sk is always exist, so when it is NULL, oops will happen.

Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Reviewed-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-03-28 17:59:29 +02:00
Pablo Neira Ayuso
b301f25387 netfilter: x_tables: enforce nul-terminated table name from getsockopt GET_ENTRIES
Make sure the table names via getsockopt GET_ENTRIES is nul-terminated
in ebtables and all the x_tables variants and their respective compat
code. Uncovered by KASAN.

Reported-by: Baozeng Ding <sploving1@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-03-28 17:59:24 +02:00
Florian Westphal
54d83fc74a netfilter: x_tables: fix unconditional helper
Ben Hawkes says:

 In the mark_source_chains function (net/ipv4/netfilter/ip_tables.c) it
 is possible for a user-supplied ipt_entry structure to have a large
 next_offset field. This field is not bounds checked prior to writing a
 counter value at the supplied offset.

Problem is that mark_source_chains should not have been called --
the rule doesn't have a next entry, so its supposed to return
an absolute verdict of either ACCEPT or DROP.

However, the function conditional() doesn't work as the name implies.
It only checks that the rule is using wildcard address matching.

However, an unconditional rule must also not be using any matches
(no -m args).

The underflow validator only checked the addresses, therefore
passing the 'unconditional absolute verdict' test, while
mark_source_chains also tested for presence of matches, and thus
proceeeded to the next (not-existent) rule.

Unify this so that all the callers have same idea of 'unconditional rule'.

Reported-by: Ben Hawkes <hawkes@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-03-28 17:59:15 +02:00
Florian Westphal
6e94e0cfb0 netfilter: x_tables: make sure e->next_offset covers remaining blob size
Otherwise this function may read data beyond the ruleset blob.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-03-28 17:59:08 +02:00
Florian Westphal
bdf533de69 netfilter: x_tables: validate e->target_offset early
We should check that e->target_offset is sane before
mark_source_chains gets called since it will fetch the target entry
for loop detection.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-03-28 17:59:04 +02:00
David S. Miller
1cdba55055 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
Pablo Neira Ayuso says:

====================
Netfilter/IPVS/OVS updates for net-next

The following patchset contains Netfilter/IPVS fixes and OVS NAT
support, more specifically this batch is composed of:

1) Fix a crash in ipset when performing a parallel flush/dump with
   set:list type, from Jozsef Kadlecsik.

2) Make sure NFACCT_FILTER_* netlink attributes are in place before
   accessing them, from Phil Turnbull.

3) Check return error code from ip_vs_fill_iph_skb_off() in IPVS SIP
   helper, from Arnd Bergmann.

4) Add workaround to IPVS to reschedule existing connections to new
   destination server by dropping the packet and wait for retransmission
   of TCP syn packet, from Julian Anastasov.

5) Allow connection rescheduling in IPVS when in CLOSE state, also
   from Julian.

6) Fix wrong offset of SIP Call-ID in IPVS helper, from Marco Angaroni.

7) Validate IPSET_ATTR_ETHER netlink attribute length, from Jozsef.

8) Check match/targetinfo netlink attribute size in nft_compat,
   patch from Florian Westphal.

9) Check for integer overflow on 32-bit systems in x_tables, from
   Florian Westphal.

Several patches from Jarno Rajahalme to prepare the introduction of
NAT support to OVS based on the Netfilter infrastructure:

10) Schedule IP_CT_NEW_REPLY definition for removal in
    nf_conntrack_common.h.

11) Simplify checksumming recalculation in nf_nat.

12) Add comments to the openvswitch conntrack code, from Jarno.

13) Update the CT state key only after successful nf_conntrack_in()
    invocation.

14) Find existing conntrack entry after upcall.

15) Handle NF_REPEAT case due to templates in nf_conntrack_in().

16) Call the conntrack helper functions once the conntrack has been
    confirmed.

17) And finally, add the NAT interface to OVS.

The batch closes with:

18) Cleanup to use spin_unlock_wait() instead of
    spin_lock()/spin_unlock(), from Nicholas Mc Guire.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-14 22:10:25 -04:00
Jarno Rajahalme
264619055b netfilter: Allow calling into nat helper without skb_dst.
NAT checksum recalculation code assumes existence of skb_dst, which
becomes a problem for a later patch in the series ("openvswitch:
Interface with NAT.").  Simplify this by removing the check on
skb_dst, as the checksum will be dealt with later in the stack.

Suggested-by: Pravin Shelar <pshelar@nicira.com>
Signed-off-by: Jarno Rajahalme <jarno@ovn.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-03-14 23:47:27 +01:00
David S. Miller
fbd40ea018 ipv4: Don't do expensive useless work during inetdev destroy.
When an inetdev is destroyed, every address assigned to the interface
is removed.  And in this scenerio we do two pointless things which can
be very expensive if the number of assigned interfaces is large:

1) Address promotion.  We are deleting all addresses, so there is no
   point in doing this.

2) A full nf conntrack table purge for every address.  We only need to
   do this once, as is already caught by the existing
   masq_dev_notifier so masq_inet_event() can skip this.

Reported-by: Solar Designer <solar@openwall.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Tested-by: Cyrill Gorcunov <gorcunov@openvz.org>
2016-03-13 23:28:35 -04:00
Pablo Neira Ayuso
8a6bf5da1a netfilter: nft_masq: support port range
Complete masquerading support by allowing port range selection.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-03-02 20:05:27 +01:00
Florian Westphal
b9e69e1273 netfilter: xtables: don't hook tables by default
delay hook registration until the table is being requested inside a
namespace.

Historically, a particular table (iptables mangle, ip6tables filter, etc)
was registered on module load.

When netns support was added to iptables only the ip/ip6tables ruleset was
made namespace aware, not the actual hook points.

This means f.e. that when ipt_filter table/module is loaded on a system,
then each namespace on that system has an (empty) iptables filter ruleset.

In other words, if a namespace sends a packet, such skb is 'caught' by
netfilter machinery and fed to hooking points for that table (i.e. INPUT,
FORWARD, etc).

Thanks to Eric Biederman, hooks are no longer global, but per namespace.

This means that we can avoid allocation of empty ruleset in a namespace and
defer hook registration until we need the functionality.

We register a tables hook entry points ONLY in the initial namespace.
When an iptables get/setockopt is issued inside a given namespace, we check
if the table is found in the per-namespace list.

If not, we attempt to find it in the initial namespace, and, if found,
create an empty default table in the requesting namespace and register the
needed hooks.

Hook points are destroyed only once namespace is deleted, there is no
'usage count' (it makes no sense since there is no 'remove table' operation
in xtables api).

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-03-02 20:05:24 +01:00
Florian Westphal
a67dd266ad netfilter: xtables: prepare for on-demand hook register
This change prepares for upcoming on-demand xtables hook registration.

We change the protoypes of the register/unregister functions.
A followup patch will then add nf_hook_register/unregister calls
to the iptables one.

Once a hook is registered packets will be picked up, so all assignments
of the form

net->ipv4.iptable_$table = new_table

have to be moved to ip(6)t_register_table, else we can see NULL
net->ipv4.iptable_$table later.

This patch doesn't change functionality; without this the actual change
simply gets too big.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-03-02 20:05:23 +01:00
Joe Stringer
5f547391f5 netfilter: nf_defrag_ipv4: Drop redundant ip_send_check()
Since commit 0848f6428b ("inet: frags: fix defragmented packet's IP
header for af_packet"), ip_send_check() would be called twice for
defragmentation that occurs from netfilter ipv4 defrag hooks. Remove the
extra call.

Signed-off-by: Joe Stringer <joe@ovn.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-03-02 20:05:22 +01:00
Nikolay Borisov
fa50d974d1 ipv4: Namespaceify ip_default_ttl sysctl knob
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-16 20:42:54 -05:00
Joe Stringer
8282f27449 inet: frag: Always orphan skbs inside ip_defrag()
Later parts of the stack (including fragmentation) expect that there is
never a socket attached to frag in a frag_list, however this invariant
was not enforced on all defrag paths. This could lead to the
BUG_ON(skb->sk) during ip_do_fragment(), as per the call stack at the
end of this commit message.

While the call could be added to openvswitch to fix this particular
error, the head and tail of the frags list are already orphaned
indirectly inside ip_defrag(), so it seems like the remaining fragments
should all be orphaned in all circumstances.

kernel BUG at net/ipv4/ip_output.c:586!
[...]
Call Trace:
 <IRQ>
 [<ffffffffa0205270>] ? do_output.isra.29+0x1b0/0x1b0 [openvswitch]
 [<ffffffffa02167a7>] ovs_fragment+0xcc/0x214 [openvswitch]
 [<ffffffff81667830>] ? dst_discard_out+0x20/0x20
 [<ffffffff81667810>] ? dst_ifdown+0x80/0x80
 [<ffffffffa0212072>] ? find_bucket.isra.2+0x62/0x70 [openvswitch]
 [<ffffffff810e0ba5>] ? mod_timer_pending+0x65/0x210
 [<ffffffff810b732b>] ? __lock_acquire+0x3db/0x1b90
 [<ffffffffa03205a2>] ? nf_conntrack_in+0x252/0x500 [nf_conntrack]
 [<ffffffff810b63c4>] ? __lock_is_held+0x54/0x70
 [<ffffffffa02051a3>] do_output.isra.29+0xe3/0x1b0 [openvswitch]
 [<ffffffffa0206411>] do_execute_actions+0xe11/0x11f0 [openvswitch]
 [<ffffffff810b63c4>] ? __lock_is_held+0x54/0x70
 [<ffffffffa0206822>] ovs_execute_actions+0x32/0xd0 [openvswitch]
 [<ffffffffa020b505>] ovs_dp_process_packet+0x85/0x140 [openvswitch]
 [<ffffffff810b63c4>] ? __lock_is_held+0x54/0x70
 [<ffffffffa02068a2>] ovs_execute_actions+0xb2/0xd0 [openvswitch]
 [<ffffffffa020b505>] ovs_dp_process_packet+0x85/0x140 [openvswitch]
 [<ffffffffa0215019>] ? ovs_ct_get_labels+0x49/0x80 [openvswitch]
 [<ffffffffa0213a1d>] ovs_vport_receive+0x5d/0xa0 [openvswitch]
 [<ffffffff810b732b>] ? __lock_acquire+0x3db/0x1b90
 [<ffffffff810b732b>] ? __lock_acquire+0x3db/0x1b90
 [<ffffffff810b732b>] ? __lock_acquire+0x3db/0x1b90
 [<ffffffffa0214895>] ? internal_dev_xmit+0x5/0x140 [openvswitch]
 [<ffffffffa02148fc>] internal_dev_xmit+0x6c/0x140 [openvswitch]
 [<ffffffffa0214895>] ? internal_dev_xmit+0x5/0x140 [openvswitch]
 [<ffffffff81660299>] dev_hard_start_xmit+0x2b9/0x5e0
 [<ffffffff8165fc21>] ? netif_skb_features+0xd1/0x1f0
 [<ffffffff81660f20>] __dev_queue_xmit+0x800/0x930
 [<ffffffff81660770>] ? __dev_queue_xmit+0x50/0x930
 [<ffffffff810b53f1>] ? mark_held_locks+0x71/0x90
 [<ffffffff81669876>] ? neigh_resolve_output+0x106/0x220
 [<ffffffff81661060>] dev_queue_xmit+0x10/0x20
 [<ffffffff816698e8>] neigh_resolve_output+0x178/0x220
 [<ffffffff816a8e6f>] ? ip_finish_output2+0x1ff/0x590
 [<ffffffff816a8e6f>] ip_finish_output2+0x1ff/0x590
 [<ffffffff816a8cee>] ? ip_finish_output2+0x7e/0x590
 [<ffffffff816a9a31>] ip_do_fragment+0x831/0x8a0
 [<ffffffff816a8c70>] ? ip_copy_metadata+0x1b0/0x1b0
 [<ffffffff816a9ae3>] ip_fragment.constprop.49+0x43/0x80
 [<ffffffff816a9c9c>] ip_finish_output+0x17c/0x340
 [<ffffffff8169a6f4>] ? nf_hook_slow+0xe4/0x190
 [<ffffffff816ab4c0>] ip_output+0x70/0x110
 [<ffffffff816a9b20>] ? ip_fragment.constprop.49+0x80/0x80
 [<ffffffff816aa9f9>] ip_local_out+0x39/0x70
 [<ffffffff816abf89>] ip_send_skb+0x19/0x40
 [<ffffffff816abfe3>] ip_push_pending_frames+0x33/0x40
 [<ffffffff816df21a>] icmp_push_reply+0xea/0x120
 [<ffffffff816df93d>] icmp_reply.constprop.23+0x1ed/0x230
 [<ffffffff816df9ce>] icmp_echo.part.21+0x4e/0x50
 [<ffffffff810b63c4>] ? __lock_is_held+0x54/0x70
 [<ffffffff810d5f9e>] ? rcu_read_lock_held+0x5e/0x70
 [<ffffffff816dfa06>] icmp_echo+0x36/0x70
 [<ffffffff816e0d11>] icmp_rcv+0x271/0x450
 [<ffffffff816a4ca7>] ip_local_deliver_finish+0x127/0x3a0
 [<ffffffff816a4bc1>] ? ip_local_deliver_finish+0x41/0x3a0
 [<ffffffff816a5160>] ip_local_deliver+0x60/0xd0
 [<ffffffff816a4b80>] ? ip_rcv_finish+0x560/0x560
 [<ffffffff816a46fd>] ip_rcv_finish+0xdd/0x560
 [<ffffffff816a5453>] ip_rcv+0x283/0x3e0
 [<ffffffff810b6302>] ? match_held_lock+0x192/0x200
 [<ffffffff816a4620>] ? inet_del_offload+0x40/0x40
 [<ffffffff8165d062>] __netif_receive_skb_core+0x392/0xae0
 [<ffffffff8165e68e>] ? process_backlog+0x8e/0x230
 [<ffffffff810b53f1>] ? mark_held_locks+0x71/0x90
 [<ffffffff8165d7c8>] __netif_receive_skb+0x18/0x60
 [<ffffffff8165e678>] process_backlog+0x78/0x230
 [<ffffffff8165e6dd>] ? process_backlog+0xdd/0x230
 [<ffffffff8165e355>] net_rx_action+0x155/0x400
 [<ffffffff8106b48c>] __do_softirq+0xcc/0x420
 [<ffffffff816a8e87>] ? ip_finish_output2+0x217/0x590
 [<ffffffff8178e78c>] do_softirq_own_stack+0x1c/0x30
 <EOI>
 [<ffffffff8106b88e>] do_softirq+0x4e/0x60
 [<ffffffff8106b948>] __local_bh_enable_ip+0xa8/0xb0
 [<ffffffff816a8eb0>] ip_finish_output2+0x240/0x590
 [<ffffffff816a9a31>] ? ip_do_fragment+0x831/0x8a0
 [<ffffffff816a9a31>] ip_do_fragment+0x831/0x8a0
 [<ffffffff816a8c70>] ? ip_copy_metadata+0x1b0/0x1b0
 [<ffffffff816a9ae3>] ip_fragment.constprop.49+0x43/0x80
 [<ffffffff816a9c9c>] ip_finish_output+0x17c/0x340
 [<ffffffff8169a6f4>] ? nf_hook_slow+0xe4/0x190
 [<ffffffff816ab4c0>] ip_output+0x70/0x110
 [<ffffffff816a9b20>] ? ip_fragment.constprop.49+0x80/0x80
 [<ffffffff816aa9f9>] ip_local_out+0x39/0x70
 [<ffffffff816abf89>] ip_send_skb+0x19/0x40
 [<ffffffff816abfe3>] ip_push_pending_frames+0x33/0x40
 [<ffffffff816d55d3>] raw_sendmsg+0x7d3/0xc30
 [<ffffffff810b732b>] ? __lock_acquire+0x3db/0x1b90
 [<ffffffff816e7557>] ? inet_sendmsg+0xc7/0x1d0
 [<ffffffff810b63c4>] ? __lock_is_held+0x54/0x70
 [<ffffffff816e759a>] inet_sendmsg+0x10a/0x1d0
 [<ffffffff816e7495>] ? inet_sendmsg+0x5/0x1d0
 [<ffffffff8163e398>] sock_sendmsg+0x38/0x50
 [<ffffffff8163ec5f>] ___sys_sendmsg+0x25f/0x270
 [<ffffffff811aadad>] ? handle_mm_fault+0x8dd/0x1320
 [<ffffffff8178c147>] ? _raw_spin_unlock+0x27/0x40
 [<ffffffff810529b2>] ? __do_page_fault+0x1e2/0x460
 [<ffffffff81204886>] ? __fget_light+0x66/0x90
 [<ffffffff8163f8e2>] __sys_sendmsg+0x42/0x80
 [<ffffffff8163f932>] SyS_sendmsg+0x12/0x20
 [<ffffffff8178cb17>] entry_SYSCALL_64_fastpath+0x12/0x6f
Code: 00 00 44 89 e0 e9 7c fb ff ff 4c 89 ff e8 e7 e7 ff ff 41 8b 9d 80 00 00 00 2b 5d d4 89 d8 c1 f8 03 0f b7 c0 e9 33 ff ff f
 66 66 66 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90 55 48
RIP  [<ffffffff816a9a92>] ip_do_fragment+0x892/0x8a0
 RSP <ffff88006d603170>

Fixes: 7f8a436eaa ("openvswitch: Add conntrack action")
Signed-off-by: Joe Stringer <joe@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-28 16:00:46 -08:00
Pablo Neira Ayuso
df05ef874b netfilter: nf_tables: release objects on netns destruction
We have to release the existing objects on netns removal otherwise we
leak them. Chains are unregistered in first place to make sure no
packets are walking on our rules and sets anymore.

The object release happens by when we unregister the family via
nft_release_afinfo() which is called from nft_unregister_afinfo() from
the corresponding __net_exit path in every family.

Reported-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-12-28 18:34:35 +01:00
David S. Miller
59ce9670ce Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

The following patchset contains the first batch of Netfilter updates for
the upcoming 4.5 kernel. This batch contains userspace netfilter header
compilation fixes, support for packet mangling in nf_tables, the new
tracing infrastructure for nf_tables and cgroup2 support for iptables.
More specifically, they are:

1) Two patches to include dependencies in our netfilter userspace
   headers to resolve compilation problems, from Mikko Rapeli.

2) Four comestic cleanup patches for the ebtables codebase, from Ian Morris.

3) Remove duplicate include in the netfilter reject infrastructure,
   from Stephen Hemminger.

4) Two patches to simplify the netfilter defragmentation code for IPv6,
   patch from Florian Westphal.

5) Fix root ownership of /proc/net netfilter for unpriviledged net
   namespaces, from Philip Whineray.

6) Get rid of unused fields in struct nft_pktinfo, from Florian Westphal.

7) Add mangling support to our nf_tables payload expression, from
   Patrick McHardy.

8) Introduce a new netlink-based tracing infrastructure for nf_tables,
   from Florian Westphal.

9) Change setter functions in nfnetlink_log to be void, from
    Rami Rosen.

10) Add netns support to the cttimeout infrastructure.

11) Add cgroup2 support to iptables, from Tejun Heo.

12) Introduce nfnl_dereference_protected() in nfnetlink, from Florian.

13) Add support for mangling pkttype in the nf_tables meta expression,
    also from Florian.

BTW, I need that you pull net into net-next, I have another batch that
requires changes that I don't yet see in net.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-18 15:37:42 -05:00
David S. Miller
b3e0d3d7ba Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/geneve.c

Here we had an overlapping change, where in 'net' the extraneous stats
bump was being removed whilst in 'net-next' the final argument to
udp_tunnel6_xmit_skb() was being changed.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-17 22:08:28 -05:00
Tom Herbert
c8cd0989bd net: Eliminate NETIF_F_GEN_CSUM and NETIF_F_V[46]_CSUM
These netif flags are unnecessary convolutions. It is more
straightforward to just use NETIF_F_HW_CSUM, NETIF_F_IP_CSUM,
and NETIF_F_IPV6_CSUM directly.

This patch also:
    - Cleans up can_checksum_protocol
    - Simplifies netdev_intersect_features

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-15 16:50:20 -05:00
Pablo Neira Ayuso
d3340b79ec netfilter: nf_dup: add missing dependencies with NF_CONNTRACK
CONFIG_NF_CONNTRACK=m
CONFIG_NF_DUP_IPV4=y

results in:

   net/built-in.o: In function `nf_dup_ipv4':
>> (.text+0xd434f): undefined reference to `nf_conntrack_untracked'

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-12-10 18:17:06 +01:00
stephen hemminger
a18fd970ce netfilter: remove duplicate include
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-11-23 17:54:43 +01:00
Bastian Stender
09605cc12c net ipv4: use preferred log methods
Replace printk calls with preferred unconditional log method calls to keep
kernel messages clean.

Added newline to "too small MTU" message.

Signed-off-by: Bastian Stender <bst@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-18 13:37:20 -05:00