| commit | 61fdfd51d1dd5bd4f3bc02b332b265c28e879221 | [log] [tgz] |
|---|---|---|
| author | Jing Peng <jing@meter.com> | Fri Jul 15 15:12:29 2022 -0400 |
| committer | Ole Tr�an <otroan@employees.org> | Mon Nov 07 08:00:23 2022 +0000 |
| tree | 414b4893346d8dccddf44723fdccd802dee7db2b | |
| parent | 9ff833d8f4ccccc475f9a302b8f70eed49963472 [diff] |
nat: fix per-vrf session bookkeeping
Each NAT44 ED session has a per_vrf_sessions_index referencing
an element in the thread-local vector per_vrf_sessions_vec.
However this index can be possibly invalidated by vec_del1() in
per_vrf_sessions_cleanup(), before a session is registered.
Such a stale index can cause an assertion failure in function
per_vrf_sessions_is_expired() when we use it to locate the
per_vrf_sessions object.
A possible sequence to reproduce is:
1. Create two NAT44 ED sessions s1, s2 so that two per_vrf_sessions are created:
index 0: between VRF pair 10 and 11 (expired=0, ses_count=1)
index 1: between VRF pair 20 and 21 (expired=0, ses_count=1)
For the sessions we have:
s1->per_vrf_sessions_index == 0
s2->per_vrf_sessions_index == 1
2. Delete the first session via CLI, now the two per_vrf_sessions become:
index 0: between VRF pair 10 and 11 (expired=0, ses_count=0)
index 1: between VRF pair 20 and 21 (expired=0, ses_count=1)
For the sessions we have:
s2->per_vrf_sessions_index == 1
3. Delete the VRF 11:
index 0: between VRF pair 10 and 11 (expired=1, ses_count=0)
index 1: between VRF pair 20 and 21 (expired=0, ses_count=1)
For the sessions we have:
s2->per_vrf_sessions_index == 1
4. Create a new session s3 between VRF pair 20 and 21 so that the first
per_vrf_sessions will be deleted:
index 0: between VRF pair 20 and 21 (expired=0, ses_count=2)
For the sessions we have:
s2->per_vrf_sessions_index == 1
s3->per_vrf_sessions_index == 0
Here, note that the actual index of per_vrf_session is changed due
to vec_del1(). The new session is added after the cleanup so it gets
the correct index. But the index held by the existing session is not
updated.
5. Trigger the fast path of the session s2. To achieve this, session
s2 could be created in step 1 by
ping -i20 -Iiface_in_vrf_10 1.1.1.1
and steps 2-4 should then be performed within the 20-second interval.
This patch fixes this by changing per_vrf_sessions_vec to a pool so
that indicies are kept intact.
Type: fix
Signed-off-by: Jing Peng <jing@meter.com>
Change-Id: I4c08f9bfd50134bcb5f08e50ad61af2bddbcb645
The VPP platform is an extensible framework that provides out-of-the-box production quality switch/router functionality. It is the open source version of Cisco's Vector Packet Processing (VPP) technology: a high performance, packet-processing stack that can run on commodity CPUs.
The benefits of this implementation of VPP are its high performance, proven technology, its modularity and flexibility, and rich feature set.
For more information on VPP and its features please visit the FD.io website and What is VPP? pages.
Details of the changes leading up to this version of VPP can be found under doc/releasenotes.
| Directory name | Description |
|---|---|
| build-data | Build metadata |
| build-root | Build output directory |
| docs | Sphinx Documentation |
| dpdk | DPDK patches and build infrastructure |
| extras/libmemif | Client library for memif |
| src/examples | VPP example code |
| src/plugins | VPP bundled plugins directory |
| src/svm | Shared virtual memory allocation library |
| src/tests | Standalone tests (not part of test harness) |
| src/vat | VPP API test program |
| src/vlib | VPP application library |
| src/vlibapi | VPP API library |
| src/vlibmemory | VPP Memory management |
| src/vnet | VPP networking |
| src/vpp | VPP application |
| src/vpp-api | VPP application API bindings |
| src/vppinfra | VPP core library |
| src/vpp/api | Not-yet-relocated API bindings |
| test | Unit tests and Python test harness |
In general anyone interested in building, developing or running VPP should consult the VPP wiki for more complete documentation.
In particular, readers are recommended to take a look at [Pulling, Building, Running, Hacking, Pushing](https://wiki.fd.io/view/VPP/Pulling,_Building,_Run ning,_Hacking_and_Pushing_VPP_Code) which provides extensive step-by-step coverage of the topic.
For the impatient, some salient information is distilled below.
To install system dependencies, build VPP and then install it, simply run the build script. This should be performed a non-privileged user with sudo access from the project base directory:
./extras/vagrant/build.sh
If you want a more fine-grained approach because you intend to do some development work, the Makefile in the root directory of the source tree provides several convenience shortcuts as make targets that may be of interest. To see the available targets run:
make
The directory extras/vagrant contains a VagrantFile and supporting scripts to bootstrap a working VPP inside a Vagrant-managed Virtual Machine. This VM can then be used to test concepts with VPP or as a development platform to extend VPP. Some obvious caveats apply when using a VM for VPP since its performance will never match that of bare metal; if your work is timing or performance sensitive, consider using bare metal in addition or instead of the VM.
For this to work you will need a working installation of Vagrant. Instructions for this can be found [on the Setting up Vagrant wiki page] (https://wiki.fd.io/view/DEV/Setting_Up_Vagrant).
Several modules provide documentation, see @subpage user_doc for more end-user-oriented information. Also see @subpage dev_doc for developer notes.
Visit the VPP wiki for details on more advanced building strategies and other development notes.