kernel/tools/testing/selftests/wireguard/netns.sh, branch linux-6.2.y

wireguard: selftests: limit parallelism to $(nproc) tests at once

2022-05-05T00:49:56Z

The parallel tests were added to catch queueing issues from multiple cores. But what happens in reality when testing tons of processes is that these separate threads wind up fighting with the scheduler, and we wind up with contention in places we don't care about that decrease the chances of hitting a bug. So just do a test with the number of CPU cores, rather than trying to scale up arbitrarily. Signed-off-by: Jason A. Donenfeld Signed-off-by: Jakub Kicinski

wireguard: selftests: make routing loop test non-fatal

2022-05-05T00:49:56Z

I hate to do this, but I still do not have a good solution to actually fix this bug across architectures. So just disable it for now, so that the CI can still deliver actionable results. This commit adds a large red warning, so that at least the failure isn't lost forever, and hopefully this can be revisited down the line. Link: https://lore.kernel.org/netdev/CAHmME9pv1x6C4TNdL6648HydD8r+txpV4hTUXOBVkrapBXH4QQ@mail.gmail.com/ Link: https://lore.kernel.org/netdev/YmszSXueTxYOC41G@zx2c4.com/ Link: https://lore.kernel.org/wireguard/CAHmME9rNnBiNvBstb7MPwK-7AmAN0sOfnhdR=eeLrowWcKxaaQ@mail.gmail.com/ Signed-off-by: Jason A. Donenfeld Signed-off-by: Jakub Kicinski

wireguard: device: reset peer src endpoint when netns exits

2021-11-30T03:50:45Z

Each peer's endpoint contains a dst_cache entry that takes a reference to another netdev. When the containing namespace exits, we take down the socket and prevent future sockets from being created (by setting creating_net to NULL), which removes that potential reference on the netns. However, it doesn't release references to the netns that a netdev cached in dst_cache might be taking, so the netns still might fail to exit. Since the socket is gimped anyway, we can simply clear all the dst_caches (by way of clearing the endpoint src), which will release all references. However, the current dst_cache_reset function only releases those references lazily. But it turns out that all of our usages of wg_socket_clear_peer_endpoint_src are called from contexts that are not exactly high-speed or bottle-necked. For example, when there's connection difficulty, or when userspace is reconfiguring the interface. And in particular for this patch, when the netns is exiting. So for those cases, it makes more sense to call dst_release immediately. For that, we add a small helper function to dst_cache. This patch also adds a test to netns.sh from Hangbin Liu to ensure this doesn't regress. Tested-by: Hangbin Liu Reported-by: Xiumei Mu Cc: Toke Høiland-Jørgensen Cc: Paolo Abeni Fixes: 900575aa33a3 ("wireguard: device: avoid circular netns references") Signed-off-by: Jason A. Donenfeld Signed-off-by: Jakub Kicinski

wireguard: selftests: actually test for routing loops

2021-11-30T03:50:29Z

We previously removed the restriction on looping to self, and then added a test to make sure the kernel didn't blow up during a routing loop. The kernel didn't blow up, thankfully, but on certain architectures where skb fragmentation is easier, such as ppc64, the skbs weren't actually being discarded after a few rounds through. But the test wasn't catching this. So actually test explicitly for massive increases in tx to see if we have a routing loop. Note that the actual loop problem will need to be addressed in a different commit. Fixes: b673e24aad36 ("wireguard: socket: remove errant restriction on looping to self") Signed-off-by: Jason A. Donenfeld Signed-off-by: Jakub Kicinski

wireguard: selftests: make sure rp_filter is disabled on vethc

2021-06-04T21:25:14Z

Some distros may enable strict rp_filter by default, which will prevent vethc from receiving the packets with an unrouteable reverse path address. Reported-by: Hangbin Liu Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Cc: stable@vger.kernel.org Signed-off-by: Jason A. Donenfeld Signed-off-by: David S. Miller

wireguard: selftests: test multiple parallel streams

2021-02-23T23:54:07Z

In order to test ndo_start_xmit being called in parallel, explicitly add separate tests, which should all run on different cores. This should help tease out bugs associated with queueing up packets from different cores in parallel. Currently, it hasn't found those types of bugs, but given future planned work, this is a useful regression to avoid. Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Signed-off-by: Jason A. Donenfeld Signed-off-by: Jakub Kicinski

wireguard: selftests: check that route_me_harder packets use the right sk

2020-10-30T11:57:38Z

If netfilter changes the packet mark, the packet is rerouted. The ip_route_me_harder family of functions fails to use the right sk, opting to instead use skb->sk, resulting in a routing loop when used with tunnels. With the next change fixing this issue in netfilter, test for the relevant condition inside our test suite, since wireguard was where the bug was discovered. Reported-by: Chen Minqiang Signed-off-by: Jason A. Donenfeld Signed-off-by: Pablo Neira Ayuso

wireguard: device: avoid circular netns references

2020-06-23T21:50:34Z

Before, we took a reference to the creating netns if the new netns was different. This caused issues with circular references, with two wireguard interfaces swapping namespaces. The solution is to rather not take any extra references at all, but instead simply invalidate the creating netns pointer when that netns is deleted. In order to prevent this from happening again, this commit improves the rough object leak tracking by allowing it to account for created and destroyed interfaces, aside from just peers and keys. That then makes it possible to check for the object leak when having two interfaces take a reference to each others' namespaces. Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Signed-off-by: Jason A. Donenfeld Signed-off-by: David S. Miller

wireguard: socket: remove errant restriction on looping to self

2020-05-07T03:03:47Z

It's already possible to create two different interfaces and loop packets between them. This has always been possible with tunnels in the kernel, and isn't specific to wireguard. Therefore, the networking stack already needs to deal with that. At the very least, the packet winds up exceeding the MTU and is discarded at that point. So, since this is already something that happens, there's no need to forbid the not very exceptional case of routing a packet back to the same interface; this loop is no different than others, and we shouldn't special case it, but rather rely on generic handling of loops in general. This also makes it easier to do interesting things with wireguard such as onion routing. At the same time, we add a selftest for this, ensuring that both onion routing works and infinite routing loops do not crash the kernel. We also add a test case for wireguard interfaces nesting packets and sending traffic between each other, as well as the loop in this case too. We make sure to send some throughput-heavy traffic for this use case, to stress out any possible recursion issues with the locks around workqueues. Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Signed-off-by: Jason A. Donenfeld Signed-off-by: David S. Miller

wireguard: noise: error out precomputed DH during handshake rather than config

2020-03-19T01:51:43Z

We precompute the static-static ECDH during configuration time, in order to save an expensive computation later when receiving network packets. However, not all ECDH computations yield a contributory result. Prior, we were just not letting those peers be added to the interface. However, this creates a strange inconsistency, since it was still possible to add other weird points, like a valid public key plus a low-order point, and, like points that result in zeros, a handshake would not complete. In order to make the behavior more uniform and less surprising, simply allow all peers to be added. Then, we'll error out later when doing the crypto if there's an issue. This also adds more separation between the crypto layer and the configuration layer. Discussed-with: Mathias Hall-Andersen Signed-off-by: Jason A. Donenfeld Signed-off-by: David S. Miller