summaryrefslogtreecommitdiff
path: root/drivers/net/wireguard/selftest
AgeCommit message (Collapse)Author
2021-06-04wireguard: allowedips: free empty intermediate nodes when removing single nodeJason A. Donenfeld
When removing single nodes, it's possible that that node's parent is an empty intermediate node, in which case, it too should be removed. Otherwise the trie fills up and never is fully emptied, leading to gradual memory leaks over time for tries that are modified often. There was originally code to do this, but was removed during refactoring in 2016 and never reworked. Now that we have proper parent pointers from the previous commits, we can implement this properly. In order to reduce branching and expensive comparisons, we want to keep the double pointer for parent assignment (which lets us easily chain up to the root), but we still need to actually get the parent's base address. So encode the bit number into the last two bits of the pointer, and pack and unpack it as needed. This is a little bit clumsy but is the fastest and less memory wasteful of the compromises. Note that we align the root struct here to a minimum of 4, because it's embedded into a larger struct, and we're relying on having the bottom two bits for our flag, which would only be 16-bit aligned on m68k. The existing macro-based helpers were a bit unwieldy for adding the bit packing to, so this commit replaces them with safer and clearer ordinary functions. We add a test to the randomized/fuzzer part of the selftests, to free the randomized tries by-peer, refuzz it, and repeat, until it's supposed to be empty, and then then see if that actually resulted in the whole thing being emptied. That combined with kmemcheck should hopefully make sure this commit is doing what it should. Along the way this resulted in various other cleanups of the tests and fixes for recent graphviz. Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Cc: stable@vger.kernel.org Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-04wireguard: allowedips: initialize list head in selftestJason A. Donenfeld
The randomized trie tests weren't initializing the dummy peer list head, resulting in a NULL pointer dereference when used. Fix this by initializing it in the randomized trie test, just like we do for the static unit test. While we're at it, all of the other strings like this have the word "self-test", so add it to the missing place here. Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Cc: stable@vger.kernel.org Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-20wireguard: noise: separate receive counter from send counterJason A. Donenfeld
In "wireguard: queueing: preserve flow hash across packet scrubbing", we were required to slightly increase the size of the receive replay counter to something still fairly small, but an increase nonetheless. It turns out that we can recoup some of the additional memory overhead by splitting up the prior union type into two distinct types. Before, we used the same "noise_counter" union for both sending and receiving, with sending just using a simple atomic64_t, while receiving used the full replay counter checker. This meant that most of the memory being allocated for the sending counter was being wasted. Since the old "noise_counter" type increased in size in the prior commit, now is a good time to split up that union type into a distinct "noise_replay_ counter" for receiving and a boring atomic64_t for sending, each using neither more nor less memory than required. Also, since sometimes the replay counter is accessed without necessitating additional accesses to the bitmap, we can reduce cache misses by hoisting the always-necessary lock above the bitmap in the struct layout. We also change a "noise_replay_counter" stack allocation to kmalloc in a -DDEBUG selftest so that KASAN doesn't trigger a stack frame warning. All and all, removing a bit of abstraction in this commit makes the code simpler and smaller, in addition to the motivating memory usage recuperation. For example, passing around raw "noise_symmetric_key" structs is something that really only makes sense within noise.c, in the one place where the sending and receiving keys can safely be thought of as the same type of object; subsequent to that, it's important that we uniformly access these through keypair->{sending,receiving}, where their distinct roles are always made explicit. So this patch allows us to draw that distinction clearly as well. Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-06wireguard: selftests: initalize ipv6 members to NULL to squelch clang warningJason A. Donenfeld
Without setting these to NULL, clang complains in certain configurations that have CONFIG_IPV6=n: In file included from drivers/net/wireguard/ratelimiter.c:223: drivers/net/wireguard/selftest/ratelimiter.c:173:34: error: variable 'skb6' is uninitialized when used here [-Werror,-Wuninitialized] ret = timings_test(skb4, hdr4, skb6, hdr6, &test_count); ^~~~ drivers/net/wireguard/selftest/ratelimiter.c:123:29: note: initialize the variable 'skb6' to silence this warning struct sk_buff *skb4, *skb6; ^ = NULL drivers/net/wireguard/selftest/ratelimiter.c:173:40: error: variable 'hdr6' is uninitialized when used here [-Werror,-Wuninitialized] ret = timings_test(skb4, hdr4, skb6, hdr6, &test_count); ^~~~ drivers/net/wireguard/selftest/ratelimiter.c:125:22: note: initialize the variable 'hdr6' to silence this warning struct ipv6hdr *hdr6; ^ We silence this warning by setting the variables to NULL as the warning suggests. Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-08net: WireGuard secure network tunnelJason A. Donenfeld
WireGuard is a layer 3 secure networking tunnel made specifically for the kernel, that aims to be much simpler and easier to audit than IPsec. Extensive documentation and description of the protocol and considerations, along with formal proofs of the cryptography, are available at: * https://www.wireguard.com/ * https://www.wireguard.com/papers/wireguard.pdf This commit implements WireGuard as a simple network device driver, accessible in the usual RTNL way used by virtual network drivers. It makes use of the udp_tunnel APIs, GRO, GSO, NAPI, and the usual set of networking subsystem APIs. It has a somewhat novel multicore queueing system designed for maximum throughput and minimal latency of encryption operations, but it is implemented modestly using workqueues and NAPI. Configuration is done via generic Netlink, and following a review from the Netlink maintainer a year ago, several high profile userspace tools have already implemented the API. This commit also comes with several different tests, both in-kernel tests and out-of-kernel tests based on network namespaces, taking profit of the fact that sockets used by WireGuard intentionally stay in the namespace the WireGuard interface was originally created, exactly like the semantics of userspace tun devices. See wireguard.com/netns/ for pictures and examples. The source code is fairly short, but rather than combining everything into a single file, WireGuard is developed as cleanly separable files, making auditing and comprehension easier. Things are laid out as follows: * noise.[ch], cookie.[ch], messages.h: These implement the bulk of the cryptographic aspects of the protocol, and are mostly data-only in nature, taking in buffers of bytes and spitting out buffers of bytes. They also handle reference counting for their various shared pieces of data, like keys and key lists. * ratelimiter.[ch]: Used as an integral part of cookie.[ch] for ratelimiting certain types of cryptographic operations in accordance with particular WireGuard semantics. * allowedips.[ch], peerlookup.[ch]: The main lookup structures of WireGuard, the former being trie-like with particular semantics, an integral part of the design of the protocol, and the latter just being nice helper functions around the various hashtables we use. * device.[ch]: Implementation of functions for the netdevice and for rtnl, responsible for maintaining the life of a given interface and wiring it up to the rest of WireGuard. * peer.[ch]: Each interface has a list of peers, with helper functions available here for creation, destruction, and reference counting. * socket.[ch]: Implementation of functions related to udp_socket and the general set of kernel socket APIs, for sending and receiving ciphertext UDP packets, and taking care of WireGuard-specific sticky socket routing semantics for the automatic roaming. * netlink.[ch]: Userspace API entry point for configuring WireGuard peers and devices. The API has been implemented by several userspace tools and network management utility, and the WireGuard project distributes the basic wg(8) tool. * queueing.[ch]: Shared function on the rx and tx path for handling the various queues used in the multicore algorithms. * send.c: Handles encrypting outgoing packets in parallel on multiple cores, before sending them in order on a single core, via workqueues and ring buffers. Also handles sending handshake and cookie messages as part of the protocol, in parallel. * receive.c: Handles decrypting incoming packets in parallel on multiple cores, before passing them off in order to be ingested via the rest of the networking subsystem with GRO via the typical NAPI poll function. Also handles receiving handshake and cookie messages as part of the protocol, in parallel. * timers.[ch]: Uses the timer wheel to implement protocol particular event timeouts, and gives a set of very simple event-driven entry point functions for callers. * main.c, version.h: Initialization and deinitialization of the module. * selftest/*.h: Runtime unit tests for some of the most security sensitive functions. * tools/testing/selftests/wireguard/netns.sh: Aforementioned testing script using network namespaces. This commit aims to be as self-contained as possible, implementing WireGuard as a standalone module not needing much special handling or coordination from the network subsystem. I expect for future optimizations to the network stack to positively improve WireGuard, and vice-versa, but for the time being, this exists as intentionally standalone. We introduce a menu option for CONFIG_WIREGUARD, as well as providing a verbose debug log and self-tests via CONFIG_WIREGUARD_DEBUG. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Cc: David Miller <davem@davemloft.net> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: linux-crypto@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>