kernel/tools/testing/selftests/wireguard/netns.sh, branch linux-rolling-stable

wireguard: allowedips: add WGALLOWEDIP_F_REMOVE_ME flag

2025-05-27T07:06:19Z

The current netlink API for WireGuard does not directly support removal of allowed ips from a peer. A user can remove an allowed ip from a peer in one of two ways: 1. By using the WGPEER_F_REPLACE_ALLOWEDIPS flag and providing a new list of allowed ips which omits the allowed ip that is to be removed. 2. By reassigning an allowed ip to a "dummy" peer then removing that peer with WGPEER_F_REMOVE_ME. With the first approach, the driver completely rebuilds the allowed ip list for a peer. If my current configuration is such that a peer has allowed ips 192.168.0.2 and 192.168.0.3 and I want to remove 192.168.0.2 the actual transition looks like this. [192.168.0.2, 192.168.0.3] <-- Initial state [] <-- Step 1: Allowed ips removed for peer [192.168.0.3] <-- Step 2: Allowed ips added back for peer This is true even if the allowed ip list is small and the update does not need to be batched into multiple WG_CMD_SET_DEVICE requests, as the removal and subsequent addition of ips is non-atomic within a single request. Consequently, wg_allowedips_lookup_dst and wg_allowedips_lookup_src may return NULL while reconfiguring a peer even for packets bound for ips a user did not intend to remove leading to unintended interruptions in connectivity. This presents in userspace as failed calls to sendto and sendmsg for UDP sockets. In my case, I ran netperf while repeatedly reconfiguring the allowed ips for a peer with wg. /usr/local/bin/netperf -H 10.102.73.72 -l 10m -t UDP_STREAM -- -R 1 -m 1024 send_data: data send error: No route to host (errno 113) netperf: send_omni: send_data failed: No route to host While this may not be of particular concern for environments where peers and allowed ips are mostly static, systems like Cilium manage peers and allowed ips in a dynamic environment where peers (i.e. Kubernetes nodes) and allowed ips (i.e. pods running on those nodes) can frequently change making WGPEER_F_REPLACE_ALLOWEDIPS problematic. The second approach avoids any possible connectivity interruptions but is hacky and less direct, requiring the creation of a temporary peer just to dispose of an allowed ip. Introduce a new flag called WGALLOWEDIP_F_REMOVE_ME which in the same way that WGPEER_F_REMOVE_ME allows a user to remove a single peer from a WireGuard device's configuration allows a user to remove an ip from a peer's set of allowed ips. This enables incremental updates to a device's configuration without any connectivity blips or messy workarounds. A corresponding patch for wg extends the existing `wg set` interface to leverage this feature. $ wg set wg0 peer allowed-ips +192.168.88.0/24,-192.168.0.1/32 When '+' or '-' is prepended to any ip in the list, wg clears WGPEER_F_REPLACE_ALLOWEDIPS and sets the WGALLOWEDIP_F_REMOVE_ME flag on any ip prefixed with '-'. Signed-off-by: Jordan Rife [Jason: minor style nits, fixes to selftest, bump of wireguard-tools version] Signed-off-by: Jason A. Donenfeld Link: https://patch.msgid.link/20250521212707.1767879-5-Jason@zx2c4.com Signed-off-by: Paolo Abeni

wireguard: selftests: load nf_conntrack if not present

2024-11-19T03:32:27Z

Some distros may not load nf_conntrack by default, which will cause subsequent nf_conntrack sets to fail. Load this module if it is not already loaded. Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Signed-off-by: Hangbin Liu Reviewed-by: Simon Horman [ Jason: add [[ -e ... ]] check so this works in the qemu harness. ] Signed-off-by: Jason A. Donenfeld Link: https://patch.msgid.link/20241117212030.629159-4-Jason@zx2c4.com Signed-off-by: Jakub Kicinski

wireguard: netlink: send staged packets when setting initial private key

2023-07-03T08:17:52Z

Packets bound for peers can queue up prior to the device private key being set. For example, if persistent keepalive is set, a packet is queued up to be sent as soon as the device comes up. However, if the private key hasn't been set yet, the handshake message never sends, and no timer is armed to retry, since that would be pointless. But, if a user later sets a private key, the expectation is that those queued packets, such as a persistent keepalive, are actually sent. So adjust the configuration logic to account for this edge case, and add a test case to make sure this works. Maxim noticed this with a wg-quick(8) config to the tune of: [Interface] PostUp = wg set %i private-key somefile [Peer] PublicKey = ... Endpoint = ... PersistentKeepalive = 25 Here, the private key gets set after the device comes up using a PostUp script, triggering the bug. Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Cc: stable@vger.kernel.org Reported-by: Maxim Cournoyer Tested-by: Maxim Cournoyer Link: https://lore.kernel.org/wireguard/87fs7xtqrv.fsf@gmail.com/ Signed-off-by: Jason A. Donenfeld Signed-off-by: David S. Miller

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