The current SNAT implementation has several limitations:
- SNAT source port has to be specified. It is not optional.
- SNAT source port range is not supported.
- SNAT for UDP is a one-way translation. No response packets
are handled (because conntrack doesn't support UDP currently).
- SNAT and REDIRECT can't work on the same connection.
Fixes#5489
PiperOrigin-RevId: 367750325
We were opening dual-stack sockets, but tests only set iptables rules for a
single network protocol. Thus, packets (probably sent by previous tests) could
sneak in and break tests.
Tested with:
bazel test ///test/iptables:iptables_test
--test_arg=--runtime=runsc --nocache_test_results --test_output=errors
--runs_per_test=1000 --test_filter=TestFilterInputDropUDP
PiperOrigin-RevId: 357972385
We have support for the output interface name, but not for the input
interface name.
This change adds the support for the input interface name, and adds the
test cases for it.
Fixes#5300
PiperOrigin-RevId: 353179389
//test/iptables:iptables_test runs 30 seconds faster on my machine.
* Using contexts instead of many smaller timeouts makes the tests less
likely to flake and removes unnecessary complexity.
* We also use context to properly shut down concurrent goroutines and
the test container.
* Container logs are always logged.
Sending UDP packets in a loop can be done in a separate goroutine. We
can't do this in ContainerAction because the container will terminate
early.
Locally, scripts/iptables_tests.sh runs ~40 seconds faster.
Connection tracking is used to track packets in prerouting and
output hooks of iptables. The NAT rules modify the tuples in
connections. The connection tracking code modifies the packets by
looking at the modified tuples.
This change adds a layer of abstraction around the internal Docker APIs,
and eliminates all direct dependencies on Dockerfiles in the infrastructure.
A subsequent change will automated the generation of local images (with
efficient caching). Note that this change drops the use of bazel container
rules, as that experiment does not seem to be viable.
PiperOrigin-RevId: 308095430
Fixed flakes (tested via --runs_per_test=100) and added skips for
not-yet-implemented features. Once submitted, the iptables tests will be
ready to enable in kokoro.
Enables commands such as:
$ iptables -A INPUT -d 127.0.0.1 -j ACCEPT
$ iptables -t nat -A PREROUTING ! -d 127.0.0.1 -j REDIRECT
Also adds a bunch of REDIRECT+destination tests.
Added tests for tcp protocol with input and output rules including options sport and dport
Increased timeout in iptables_test as TCP tests were timing out with existing value.
It would be preferrable to test iptables via syscall tests, but there are some
problems with that approach:
* We're limited to loopback-only, as syscall tests involve only a single
container. Other link interfaces (e.g. fdbased) should be tested.
* We'd have to shell out to call iptables anyways, as the iptables syscall
interface itself is too large and complex to work with alone.
* Running the Linux/native version of the syscall test will require root, which
is a pain to configure, is inherently unsafe, and could leave host iptables
misconfigured.
Using the go_test target allows there to be no new test runner.
PiperOrigin-RevId: 285274275
Toshi Kikuchi
Kevin Krakauer
gVisor bot
Nayana Bidari
Adin Scannell