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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
This patch adds the macro MODULE_ALIAS_NFCT_HELPER that defines a
way to provide generic and persistent aliases for the connection
tracking helpers.
This next patch requires this patch.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Directly call IPv4 and IPv6 variants where the address family is
easily known.
Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Introduce expectation classes and policies. An expectation class
is used to distinguish different types of expectations by the
same helper (for example audio/video/t.120). The expectation
policy is used to hold the maximum number of expectations and
the initial timeout for each class.
The individual classes are isolated from each other, which means
that for example an audio expectation will only evict other audio
expectations.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Annotate nf_conntrack_sane variables with const qualifier and remove
a few casts.
Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
With all the users of the double pointers removed, this patch mops up by
finally replacing all occurances of sk_buff ** in the netfilter API by
sk_buff *.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Convert DEBUGP to pr_debug and fix lots of non-compiling debug statements.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Most are __read_mostly already, this changes the remaining ones.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since conntrack currently allows to use masks for every bit of both
helper and expectation tuples, we can't hash them and have to keep
them on two global lists that are searched for every new connection.
This patch removes the never used ability to use masks for the
destination part of the expectation tuple and completely removes
masks from helpers since the only reasonable choice is a full
match on l3num, protonum and src.u.all.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently there is a wild mix of nf_conntrack_expect_, nf_ct_exp_,
expect_, exp_, ...
Consistently use nf_ct_ as prefix for exported functions.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is nf_conntrack_sane, a netfilter connection tracking helper module
for the SANE protocol used by the 'saned' daemon to make scanners available
via network. The SANE protocol uses separate control & data connections,
similar to passive FTP. The helper module is needed to recognize the data
connection as RELATED to the control one.
Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
