Commit Graph

107 Commits

Author SHA1 Message Date
xiao ruizhu 3c00fb0bf0 netfilter: nf_conntrack_sip: fix expectation clash
When conntracks change during a dialog, SDP messages may be sent from
different conntracks to establish expects with identical tuples. In this
case expects conflict may be detected for the 2nd SDP message and end up
with a process failure.

The fixing here is to reuse an existing expect who has the same tuple for a
different conntrack if any.

Here are two scenarios for the case.

1)
         SERVER                   CPE

           |      INVITE SDP       |
      5060 |<----------------------|5060
           |      100 Trying       |
      5060 |---------------------->|5060
           |      183 SDP          |
      5060 |---------------------->|5060    ===> Conntrack 1
           |       PRACK           |
     50601 |<----------------------|5060
           |    200 OK (PRACK)     |
     50601 |---------------------->|5060
           |    200 OK (INVITE)    |
      5060 |---------------------->|5060
           |        ACK            |
     50601 |<----------------------|5060
           |                       |
           |<--- RTP stream ------>|
           |                       |
           |    INVITE SDP (t38)   |
     50601 |---------------------->|5060    ===> Conntrack 2

With a certain configuration in the CPE, SIP messages "183 with SDP" and
"re-INVITE with SDP t38" will go through the sip helper to create
expects for RTP and RTCP.

It is okay to create RTP and RTCP expects for "183", whose master
connection source port is 5060, and destination port is 5060.

In the "183" message, port in Contact header changes to 50601 (from the
original 5060). So the following requests e.g. PRACK and ACK are sent to
port 50601. It is a different conntrack (let call Conntrack 2) from the
original INVITE (let call Conntrack 1) due to the port difference.

In this example, after the call is established, there is RTP stream but no
RTCP stream for Conntrack 1, so the RTP expect created upon "183" is
cleared, and RTCP expect created for Conntrack 1 retains.

When "re-INVITE with SDP t38" arrives to create RTP&RTCP expects, current
ALG implementation will call nf_ct_expect_related() for RTP and RTCP. The
expects tuples are identical to those for Conntrack 1. RTP expect for
Conntrack 2 succeeds in creation as the one for Conntrack 1 has been
removed. RTCP expect for Conntrack 2 fails in creation because it has
idential tuples and 'conflict' with the one retained for Conntrack 1. And
then result in a failure in processing of the re-INVITE.

2)

    SERVER A                 CPE

       |      REGISTER     |
  5060 |<------------------| 5060  ==> CT1
       |       200         |
  5060 |------------------>| 5060
       |                   |
       |   INVITE SDP(1)   |
  5060 |<------------------| 5060
       | 300(multi choice) |
  5060 |------------------>| 5060                    SERVER B
       |       ACK         |
  5060 |<------------------| 5060
                                  |    INVITE SDP(2)    |
                             5060 |-------------------->| 5060  ==> CT2
                                  |       100           |
                             5060 |<--------------------| 5060
                                  | 200(contact changes)|
                             5060 |<--------------------| 5060
                                  |       ACK           |
                             5060 |-------------------->| 50601 ==> CT3
                                  |                     |
                                  |<--- RTP stream ---->|
                                  |                     |
                                  |       BYE           |
                             5060 |<--------------------| 50601
                                  |       200           |
                             5060 |-------------------->| 50601
       |   INVITE SDP(3)   |
  5060 |<------------------| 5060  ==> CT1

CPE sends an INVITE request(1) to Server A, and creates a RTP&RTCP expect
pair for this Conntrack 1 (CT1). Server A responds 300 to redirect to
Server B. The RTP&RTCP expect pairs created on CT1 are removed upon 300
response.

CPE sends the INVITE request(2) to Server B, and creates an expect pair
for the new conntrack (due to destination address difference), let call
CT2. Server B changes the port to 50601 in 200 OK response, and the
following requests ACK and BYE from CPE are sent to 50601. The call is
established. There is RTP stream and no RTCP stream. So RTP expect is
removed and RTCP expect for CT2 retains.

As BYE request is sent from port 50601, it is another conntrack, let call
CT3, different from CT2 due to the port difference. So the BYE request will
not remove the RTCP expect for CT2.

Then another outgoing call is made, with the same RTP port being used (not
definitely but possibly). CPE firstly sends the INVITE request(3) to Server
A, and tries to create a RTP&RTCP expect pairs for this CT1. In current ALG
implementation, the RTCP expect for CT1 fails in creation because it
'conflicts' with the residual one for CT2. As a result the INVITE request
fails to send.

Signed-off-by: xiao ruizhu <katrina.xiaorz@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-07-16 13:16:59 +02:00
Thomas Gleixner d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00
Flavio Leitner 08010a2160 netfilter: add API to manage NAT helpers.
The API allows a conntrack helper to indicate its corresponding
NAT helper which then can be loaded and reference counted.

Signed-off-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-04-30 14:19:55 +02:00
Florian Westphal 4806e97572 netfilter: replace NF_NAT_NEEDED with IS_ENABLED(CONFIG_NF_NAT)
NF_NAT_NEEDED is true whenever nat support for either ipv4 or ipv6 is
enabled.  Now that the af-specific nat configuration switches have been
removed, IS_ENABLED(CONFIG_NF_NAT) has the same effect.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-04-08 23:02:52 +02:00
Alin Nastac 29b0b5d565 netfilter: nf_conntrack_sip: remove direct dependency on IPv6
Previous implementation was not usable with CONFIG_IPV6=m.

Fixes: a3419ce335 ("netfilter: nf_conntrack_sip: add sip_external_media logic")
Signed-off-by: Alin Nastac <alin.nastac@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-03-18 16:11:54 +01:00
Alin Nastac a3419ce335 netfilter: nf_conntrack_sip: add sip_external_media logic
When enabled, the sip_external_media logic will leave SDP
payload untouched when it detects that interface towards INVITEd
party is the same with the one towards media endpoint.

The typical scenario for this logic is when a LAN SIP agent has more
than one IP address (uses a different address for media streams than
the one used on signalling stream) and it also forwards calls to a
voice mailbox located on the WAN side. In such case sip_direct_media
must be disabled (so normal calls could be handled by the SIP
helper), but media streams that are not traversing this router must
also be excluded from address translation (e.g. call forwards).

Signed-off-by: Alin Nastac <alin.nastac@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-02-16 10:49:12 +01:00
David S. Miller 90278871d4 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
Pablo Neira Ayuso says:

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

The following patchset contains Netfilter/IPVS updates for your net-next
tree, more relevant updates in this batch are:

1) Add Maglev support to IPVS. Moreover, store lastest server weight in
   IPVS since this is needed by maglev, patches from from Inju Song.

2) Preparation works to add iptables flowtable support, patches
   from Felix Fietkau.

3) Hand over flows back to conntrack slow path in case of TCP RST/FIN
   packet is seen via new teardown state, also from Felix.

4) Add support for extended netlink error reporting for nf_tables.

5) Support for larger timeouts that 23 days in nf_tables, patch from
   Florian Westphal.

6) Always set an upper limit to dynamic sets, also from Florian.

7) Allow number generator to make map lookups, from Laura Garcia.

8) Use hash_32() instead of opencode hashing in IPVS, from Vicent Bernat.

9) Extend ip6tables SRH match to support previous, next and last SID,
   from Ahmed Abdelsalam.

10) Move Passive OS fingerprint nf_osf.c, from Fernando Fernandez.

11) Expose nf_conntrack_max through ctnetlink, from Florent Fourcot.

12) Several housekeeping patches for xt_NFLOG, x_tables and ebtables,
   from Taehee Yoo.

13) Unify meta bridge with core nft_meta, then make nft_meta built-in.
   Make rt and exthdr built-in too, again from Florian.

14) Missing initialization of tbl->entries in IPVS, from Cong Wang.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-06 21:51:37 -04:00
Taehee Yoo 35341a6159 netfilter: add __exit mark to helper modules
There are no __exit mark in the helper modules.
because these exit functions used to be called by init function
but now that is not. so we can add __exit mark.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-24 10:29:14 +02:00
Florian Westphal 876c27314c netfilter: nf_conntrack_sip: allow duplicate SDP expectations
Callum Sinclair reported SIP IP Phone errors that he tracked down to
such phones sending session descriptions for different media types but
with same port numbers.

The expect core will only 'refresh' existing expectation if it is
from same master AND same expectation class (media type).
As expectation class is different, we get an error.

The SIP connection tracking code will then

1). drop the SDP packet
2). if an rtp expectation was already installed successfully,
    error on rtcp expectation will cancel the rtp one.

Make the expect core report back to caller when the conflict is due
to different expectation class and have SIP tracker ignore soft-error.

Reported-by: Callum Sinclair <Callum.Sinclair@alliedtelesis.co.nz>
Tested-by: Callum Sinclair <Callum.Sinclair@alliedtelesis.co.nz>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-09 17:05:27 +02:00
Taehee Yoo 0b35f6031a netfilter: Remove duplicated rcu_read_lock.
This patch removes duplicate rcu_read_lock().

1. IPVS part:

According to Julian Anastasov's mention, contexts of ipvs are described
at: http://marc.info/?l=netfilter-devel&m=149562884514072&w=2, in summary:

 - packet RX/TX: does not need locks because packets come from hooks.
 - sync msg RX: backup server uses RCU locks while registering new
   connections.
 - ip_vs_ctl.c: configuration get/set, RCU locks needed.
 - xt_ipvs.c: It is a netfilter match, running from hook context.

As result, rcu_read_lock and rcu_read_unlock can be removed from:

 - ip_vs_core.c: all
 - ip_vs_ctl.c:
   - only from ip_vs_has_real_service
 - ip_vs_ftp.c: all
 - ip_vs_proto_sctp.c: all
 - ip_vs_proto_tcp.c: all
 - ip_vs_proto_udp.c: all
 - ip_vs_xmit.c: all (contains only packet processing)

2. Netfilter part:

There are three types of functions that are guaranteed the rcu_read_lock().
First, as result, functions are only called by nf_hook():

 - nf_conntrack_broadcast_help(), pptp_expectfn(), set_expected_rtp_rtcp().
 - tcpmss_reverse_mtu(), tproxy_laddr4(), tproxy_laddr6().
 - match_lookup_rt6(), check_hlist(), hashlimit_mt_common().
 - xt_osf_match_packet().

Second, functions that caller already held the rcu_read_lock().
 - destroy_conntrack(), ctnetlink_conntrack_event().
 - ctnl_timeout_find_get(), nfqnl_nf_hook_drop().

Third, functions that are mixed with type1 and type2.

These functions are called by nf_hook() also these are called by
ordinary functions that already held the rcu_read_lock():

 - __ctnetlink_glue_build(), ctnetlink_expect_event().
 - ctnetlink_proto_size().

Applied files are below:

- nf_conntrack_broadcast.c, nf_conntrack_core.c, nf_conntrack_netlink.c.
- nf_conntrack_pptp.c, nf_conntrack_sip.c, nfnetlink_cttimeout.c.
- nfnetlink_queue.c, xt_TCPMSS.c, xt_TPROXY.c, xt_addrtype.c.
- xt_connlimit.c, xt_hashlimit.c, xt_osf.c

Detailed calltrace can be found at:
http://marc.info/?l=netfilter-devel&m=149667610710350&w=2

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-07-24 13:24:46 +02:00
Florian Westphal 9f0f3ebeda netfilter: helpers: remove data_len usage for inkernel helpers
No need to track this for inkernel helpers anymore as
NF_CT_HELPER_BUILD_BUG_ON checks do this now.

All inkernel helpers know what kind of structure they
stored in helper->data.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-19 17:55:17 +02:00
Florian Westphal dcf67740f2 netfilter: helper: add build-time asserts for helper data size
add a 32 byte scratch area in the helper struct instead of relying
on variable sized helpers plus compile-time asserts to let us know
if 32 bytes aren't enough anymore.

Not having variable sized helpers will later allow to add BUILD_BUG_ON
for the total size of conntrack extensions -- the helper extension is
the only one that doesn't have a fixed size.

The (useless!) NF_CT_HELPER_BUILD_BUG_ON(0); are added so that in case
someone adds a new helper and copy-pastes from one that doesn't store
private data at least some indication that this macro should be used
somehow is there...

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-19 17:55:16 +02:00
Gao Feng ec0e3f0111 netfilter: nf_ct_expect: Add nf_ct_remove_expect()
When remove one expect, it needs three statements. And there are
multiple duplicated codes in current code. So add one common function
nf_ct_remove_expect to consolidate this.

Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-06 18:39:40 +02:00
Christophe Leroy da2f27e9e6 netfilter: nf_conntrack_sip: fix wrong memory initialisation
In commit 82de0be686 ("netfilter: Add helper array
register/unregister functions"),
struct nf_conntrack_helper sip[MAX_PORTS][4] was changed to
sip[MAX_PORTS * 4], so the memory init should have been changed to
memset(&sip[4 * i], 0, 4 * sizeof(sip[i]));

But as the sip[] table is allocated in the BSS, it is already set to 0

Fixes: 82de0be686 ("netfilter: Add helper array register/unregister functions")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-03-03 13:48:31 +01:00
Gao Feng a96e66e702 netfilter: nf_ct_sip: Use mod_timer_pending()
timer_del() followed by timer_add() can be replaced by
mod_timer_pending().

Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-02-12 14:39:06 +01:00
Ulrich Weber 444f901742 netfilter: nf_conntrack_sip: extend request line validation
on SIP requests, so a fragmented TCP SIP packet from an allow header starting with
 INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE,SUBSCRIBE
 Content-Length: 0

will not bet interpreted as an INVITE request. Also Request-URI must start with an alphabetic character.

Confirm with RFC 3261
 Request-Line   =  Method SP Request-URI SP SIP-Version CRLF

Fixes: 30f33e6dee ("[NETFILTER]: nf_conntrack_sip: support method specific request/response handling")
Signed-off-by: Ulrich Weber <ulrich.weber@riverbed.com>
Acked-by: Marco Angaroni <marcoangaroni@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-10-27 18:27:59 +02:00
Marco Angaroni 1bcabc81ee netfilter: nf_ct_sip: allow tab character in SIP headers
Current parsing methods for SIP headers do not allow the presence of
tab characters between header name and header value. As a result Call-ID
SIP headers like the following are discarded by IPVS SIP persistence
engine:

"Call-ID\t: mycallid@abcde"
"Call-ID:\tmycallid@abcde"

In above examples Call-IDs are represented as strings in C language.
Obviously in real message we have byte "09" before/after colon (":").

Proposed fix is in nf_conntrack_sip module.
Function sip_skip_whitespace() should skip tabs in addition to spaces,
since in SIP grammar whitespace (WSP) corresponds to space or tab.

Below is an extract of relevant SIP ABNF syntax.

Call-ID  =  ( "Call-ID" / "i" ) HCOLON callid
callid   =  word [ "@" word ]

HCOLON  =  *( SP / HTAB ) ":" SWS
SWS     =  [LWS] ; sep whitespace
LWS     =  [*WSP CRLF] 1*WSP ; linear whitespace
WSP     =  SP / HTAB
word    =  1*(alphanum / "-" / "." / "!" / "%" / "*" /
           "_" / "+" / "`" / "'" / "~" /
           "(" / ")" / "<" / ">" /
           ":" / "\" / DQUOTE /
           "/" / "[" / "]" / "?" /
           "{" / "}" )

Signed-off-by: Marco Angaroni <marcoangaroni@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-09-07 13:53:43 +02:00
Marco Angaroni f0608ceaa7 netfilter: nf_ct_sip: correct allowed characters in Call-ID SIP header
Current parsing methods for SIP header Call-ID do not check correctly all
characters allowed by RFC 3261. In particular "," character is allowed
instead of "'" character. As a result Call-ID headers like the following
are discarded by IPVS SIP persistence engine.

Call-ID: -.!%*_+`'~()<>:\"/[]?{}

Above example is composed using all non-alphanumeric characters listed
in RFC 3261 for Call-ID header syntax.

Proposed fix is in nf_conntrack_sip module; function iswordc() checks this
range: (c >= '(' && c <= '/') which includes these characters: ()*+,-./
They are all allowed except ",". Instead "'" is not included in the list.

Below is an extract of relevant SIP ABNF syntax.

Call-ID  =  ( "Call-ID" / "i" ) HCOLON callid
callid   =  word [ "@" word ]

HCOLON  =  *( SP / HTAB ) ":" SWS
SWS     =  [LWS] ; sep whitespace
LWS     =  [*WSP CRLF] 1*WSP ; linear whitespace
WSP     =  SP / HTAB
word    =  1*(alphanum / "-" / "." / "!" / "%" / "*" /
           "_" / "+" / "`" / "'" / "~" /
           "(" / ")" / "<" / ">" /
           ":" / "\" / DQUOTE /
           "/" / "[" / "]" / "?" /
           "{" / "}" )

Signed-off-by: Marco Angaroni <marcoangaroni@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-09-07 10:37:58 +02:00
Marco Angaroni 68cb9fe47e netfilter: nf_ct_sip: correct parsing of continuation lines in SIP headers
Current parsing methods for SIP headers do not properly manage
continuation lines: in case of Call-ID header the first character of
Call-ID header value is truncated. As a result IPVS SIP persistence
engine hashes over a call-id that is not exactly the one present in
the originale message.

Example: "Call-ID: \r\n abcdeABCDE1234"
results in extracted call-id equal to "bcdeABCDE1234".

In above example Call-ID is represented as a string in C language.
Obviously in real message the first bytes after colon (":") are
"20 0d 0a 20".

Proposed fix is in nf_conntrack_sip module.
Since sip_follow_continuation() function walks past the leading
spaces or tabs of the continuation line, sip_skip_whitespace()
should simply return the ouput of sip_follow_continuation().
Otherwise another iteration of the for loop is done and dptr
is incremented by one pointing to the second character of the
first word in the header.

Below is an extract of relevant SIP ABNF syntax.

Call-ID  =  ( "Call-ID" / "i" ) HCOLON callid
callid   =  word [ "@" word ]

HCOLON  =  *( SP / HTAB ) ":" SWS
SWS     =  [LWS] ; sep whitespace
LWS     =  [*WSP CRLF] 1*WSP ; linear whitespace
WSP     =  SP / HTAB
word    =  1*(alphanum / "-" / "." / "!" / "%" / "*" /
           "_" / "+" / "`" / "'" / "~" /
           "(" / ")" / "<" / ">" /
           ":" / "\" / DQUOTE /
           "/" / "[" / "]" / "?" /
           "{" / "}" )

Signed-off-by: Marco Angaroni <marcoangaroni@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-09-07 10:37:57 +02:00
Christophe Leroy 0d35d0815b netfilter: nf_conntrack_sip: CSeq 0 is a valid CSeq
Do not drop packet when CSeq is 0 as 0 is also a valid value for CSeq.

simple_strtoul() will return 0 either when all digits are 0
or if there are no digits at all. Therefore when simple_strtoul()
returns 0 we check if first character is digit 0 or not.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-08-08 11:58:43 +02:00
Gao Feng 82de0be686 netfilter: Add helper array register/unregister functions
Add nf_ct_helper_init(), nf_conntrack_helpers_register() and
nf_conntrack_helpers_unregister() functions to avoid repetitive
opencoded initialization in helpers.

This patch keeps an id parameter for nf_ct_helper_init() not to break
helper matching by name that has been inconsistently exposed to
userspace through ports, eg. ftp-2121, and through an incremental id,
eg. tftp-1.

Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-07-21 02:31:53 +02:00
Taehee Yoo b7a8daa9f3 netfilter: nf_ct_helper: Fix helper unregister count.
helpers should unregister the only registered ports.
but, helper cannot have correct registered ports value when
failed to register.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-30 12:21:22 +02:00
Pablo Neira Ayuso ad6d950393 netfilter: nf_ct_helper: define pr_fmt()
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-01-04 17:48:51 +01:00
Rasmus Villemoes 18082746a2 netfilter: replace strnicmp with strncasecmp
The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp.  The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.

To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-14 02:18:24 +02:00
Jesper Dangaard Brouer ca7433df3a netfilter: conntrack: seperate expect locking from nf_conntrack_lock
Netfilter expectations are protected with the same lock as conntrack
entries (nf_conntrack_lock).  This patch split out expectations locking
to use it's own lock (nf_conntrack_expect_lock).

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-03-07 11:41:01 +01:00
holger@eitzenberger.org 180cf72f56 netfilter: nf_ct_sip: consolidate NAT hook functions
There are currently seven different NAT hooks used in both
nf_conntrack_sip and nf_nat_sip, each of the hooks is exported in
nf_conntrack_sip, then set from the nf_nat_sip NAT helper.

And because each of them is exported there is quite some overhead
introduced due of this.

By introducing nf_nat_sip_hooks I am able to reduce both text/data
somewhat.  For nf_conntrack_sip e. g. I get

        text             data              bss              dec
old    15243             5256               32            20531
new    15010             5192               32            20234

Signed-off-by: Holger Eitzenberger <holger@eitzenberger.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-10-01 12:47:09 +02:00
holger@eitzenberger.org b21613aeb6 netfilter: nf_ct_sip: extend RCU read lock in set_expected_rtp_rtcp()
Currently set_expected_rtp_rtcp() in the SIP helper uses
rcu_dereference() two times to access two different NAT hook
functions. However, only the first one is protected by the RCU
reader lock, but the 2nd isn't. Fix it by extending the RCU
protected area.

This is more a cosmetic thing since we rely on all netfilter hooks
being rcu_read_lock()ed by nf_hook_slow() in many places anyways,
as Patrick McHardy clarified.

Signed-off-by: Holger Eitzenberger <holger.eitzenberger@sophos.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-09-27 16:17:47 +02:00
Patrick McHardy 3a7b21eaf4 netfilter: nf_ct_sip: don't drop packets with offsets pointing outside the packet
Some Cisco phones create huge messages that are spread over multiple packets.
After calculating the offset of the SIP body, it is validated to be within
the packet and the packet is dropped otherwise. This breaks operation of
these phones. Since connection tracking is supposed to be passive, just let
those packets pass unmodified and untracked.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-04-06 14:03:18 +02:00
Sasha Levin b67bfe0d42 hlist: drop the node parameter from iterators
I'm not sure why, but the hlist for each entry iterators were conceived

        list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

        hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

 - Fix up the actual hlist iterators in linux/list.h
 - Fix up the declaration of other iterators based on the hlist ones.
 - A very small amount of places were using the 'node' parameter, this
 was modified to use 'obj->member' instead.
 - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
 properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
    <+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
    ...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:24 -08:00
Pablo Neira Ayuso b20ab9cc63 netfilter: nf_ct_helper: better logging for dropped packets
Connection tracking helpers have to drop packets under exceptional
situations. Currently, the user gets the following logging message
in case that happens:

	nf_ct_%s: dropping packet ...

However, depending on the helper, there are different reasons why a
packet can be dropped.

This patch modifies the existing code to provide more specific
error message in the scope of each helper to help users to debug
the reason why the packet has been dropped, ie:

	nf_ct_%s: dropping packet: reason ...

Thanks to Joe Perches for many formatting suggestions.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-02-19 02:48:05 +01:00
Kevin Cernekee 7266507d89 netfilter: nf_ct_sip: support Cisco 7941/7945 IP phones
Most SIP devices use a source port of 5060/udp on SIP requests, so the
response automatically comes back to port 5060:

    phone_ip:5060 -> proxy_ip:5060   REGISTER
    proxy_ip:5060 -> phone_ip:5060   100 Trying

The newer Cisco IP phones, however, use a randomly chosen high source
port for the SIP request but expect the response on port 5060:

    phone_ip:49173 -> proxy_ip:5060  REGISTER
    proxy_ip:5060 -> phone_ip:5060   100 Trying

Standard Linux NAT, with or without nf_nat_sip, will send the reply back
to port 49173, not 5060:

    phone_ip:49173 -> proxy_ip:5060  REGISTER
    proxy_ip:5060 -> phone_ip:49173  100 Trying

But the phone is not listening on 49173, so it will never see the reply.

This patch modifies nf_*_sip to work around this quirk by extracting
the SIP response port from the Via: header, iff the source IP in the
packet header matches the source IP in the SIP request.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-01-17 21:12:44 +01:00
Patrick McHardy 9a66482106 netfilter: nf_nat: support IPv6 in SIP NAT helper
Add IPv6 support to the SIP NAT helper. There are no functional differences
to IPv4 NAT, just different formats for addresses.

Signed-off-by: Patrick McHardy <kaber@trash.net>
2012-08-30 03:00:22 +02:00
Patrick McHardy c7232c9979 netfilter: add protocol independent NAT core
Convert the IPv4 NAT implementation to a protocol independent core and
address family specific modules.

Signed-off-by: Patrick McHardy <kaber@trash.net>
2012-08-30 03:00:14 +02:00
Patrick McHardy 051966c0c6 netfilter: nf_nat: add protoff argument to packet mangling functions
For mangling IPv6 packets the protocol header offset needs to be known
by the NAT packet mangling functions. Add a so far unused protoff argument
and convert the conntrack and NAT helpers to use it in preparation of
IPv6 NAT.

Signed-off-by: Patrick McHardy <kaber@trash.net>
2012-08-30 03:00:13 +02:00
Patrick McHardy 811927ccfe netfilter: nf_conntrack: restrict NAT helper invocation to IPv4
The NAT helpers currently only handle IPv4 packets correctly. Restrict
invocation of the helpers to IPv4 in preparation of IPv6 NAT.

Signed-off-by: Patrick McHardy <kaber@trash.net>
2012-08-30 03:00:12 +02:00
Patrick McHardy 02b69cbdc2 netfilter: nf_ct_sip: fix IPv6 address parsing
Within SIP messages IPv6 addresses are enclosed in square brackets in most
cases, with the exception of the "received=" header parameter. Currently
the helper fails to parse enclosed addresses.

This patch:

- changes the SIP address parsing function to enforce square brackets
  when required, and accept them when not required but present, as
  recommended by RFC 5118.

- adds a new SDP address parsing function that never accepts square
  brackets since SDP doesn't use them.

With these changes, the SIP helper correctly parses all test messages
from RFC 5118 (Session Initiation Protocol (SIP) Torture Test Messages
for Internet Protocol Version 6 (IPv6)).

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-08-10 11:53:11 +02:00
Patrick McHardy e9324b2ce6 netfilter: nf_ct_sip: fix helper name
Commit 3a8fc53a (netfilter: nf_ct_helper: allocate 16 bytes for the helper
and policy names) introduced a bug in the SIP helper, the helper name is
sprinted to the sip_names array instead of instead of into the helper
structure. This breaks the helper match and the /proc/net/nf_conntrack_expect
output.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-08-10 11:53:03 +02:00
Pablo Neira Ayuso 1afc56794e netfilter: nf_ct_helper: implement variable length helper private data
This patch uses the new variable length conntrack extensions.

Instead of using union nf_conntrack_help that contain all the
helper private data information, we allocate variable length
area to store the private helper data.

This patch includes the modification of all existing helpers.
It also includes a couple of include header to avoid compilation
warnings.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-16 15:08:55 +02:00
Pablo Neira Ayuso 3a8fc53a45 netfilter: nf_ct_helper: allocate 16 bytes for the helper and policy names
This patch modifies the struct nf_conntrack_helper to allocate
the room for the helper name. The maximum length is 16 bytes
(this was already introduced in 2.6.24).

For the maximum length for expectation policy names, I have
also selected 16 bytes.

This patch is required by the follow-up patch to support
user-space connection tracking helpers.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2012-06-16 15:08:39 +02:00
Eric Dumazet fb04883371 netfilter: add more values to enum ip_conntrack_info
Following error is raised (and other similar ones) :

net/ipv4/netfilter/nf_nat_standalone.c: In function ‘nf_nat_fn’:
net/ipv4/netfilter/nf_nat_standalone.c:119:2: warning: case value ‘4’
not in enumerated type ‘enum ip_conntrack_info’

gcc barfs on adding two enum values and getting a not enumerated
result :

case IP_CT_RELATED+IP_CT_IS_REPLY:

Add missing enum values

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: David Miller <davem@davemloft.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2011-06-06 01:35:10 +02:00
David S. Miller 30b9284db3 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/kaber/nf-2.6 2011-05-17 14:18:25 -04:00
Patrick McHardy e6e4d9ed11 netfilter: nf_ct_sip: fix SDP parsing in TCP SIP messages for some Cisco phones
Some Cisco phones do not place the Content-Length field at the end of the
SIP message. This is valid, due to a misunderstanding of the specification
the parser expects the SDP body to start directly after the Content-Length
field. Fix the parser to scan for \r\n\r\n to locate the beginning of the
SDP body.

Reported-by: Teresa Kang <teresa_kang@gemtek.com.tw>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2011-05-16 14:45:39 +02:00
Patrick McHardy 274ea0e2a4 netfilter: nf_ct_sip: validate Content-Length in TCP SIP messages
Verify that the message length of a single SIP message, which is calculated
based on the Content-Length field contained in the SIP message, does not
exceed the packet boundaries.

Signed-off-by: Patrick McHardy <kaber@trash.net>
2011-05-16 14:42:26 +02:00
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
David S. Miller 9941fb6276 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/kaber/nf-next-2.6 2010-10-21 08:21:34 -07:00
Simon Horman 001985b2c0 netfilter: nf_conntrack_sip: Add callid parser
Signed-off-by: Simon Horman <horms@verge.net.au>
Acked-by: Julian Anastasov <ja@ssi.bg>
2010-10-04 22:45:23 +09:00
Simon Horman 5adbb9fb0c netfilter: nf_conntrack_sip: Allow ct_sip_get_header() to be called with a null ct argument
Signed-off-by: Simon Horman <horms@verge.net.au>
Acked-by: Julian Anastasov <ja@ssi.bg>
2010-10-04 22:45:23 +09:00
Simon Horman 7874896a26 netfilter: nf_ct_sip: default to NF_ACCEPT in sip_help_tcp()
I initially noticed this because of the compiler warning below, but it
does seem to be a valid concern in the case where ct_sip_get_header()
returns 0 in the first iteration of the while loop.

net/netfilter/nf_conntrack_sip.c: In function 'sip_help_tcp':
net/netfilter/nf_conntrack_sip.c:1379: warning: 'ret' may be used uninitialized in this function

Signed-off-by: Simon Horman <horms@verge.net.au>
[Patrick: changed NF_DROP to NF_ACCEPT]
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-22 13:13:32 -07:00
Patrick McHardy a1d7c1b4b8 netfilter: nf_ct_sip: handle non-linear skbs
Handle non-linear skbs by linearizing them instead of silently failing.
Long term the helper should be fixed to either work with non-linear skbs
directly by using the string search API or work on a copy of the data.

Based on patch by Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-05-14 21:18:17 +02:00
Stephen Hemminger 654d0fbdc8 netfilter: cleanup printk messages
Make sure all printk messages have a severity level.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-05-13 15:02:08 +02:00