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path: root/drivers/net/wireguard/noise.c
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2023-09-15wireguard: do not include crypto/algapi.hHerbert Xu
The header file crypto/algapi.h is for internal use only. Use the header file crypto/utils.h instead. Acked-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2022-01-18lib/crypto: blake2s: move hmac construction into wireguardJason A. Donenfeld
Basically nobody should use blake2s in an HMAC construction; it already has a keyed variant. But unfortunately for historical reasons, Noise, used by WireGuard, uses HKDF quite strictly, which means we have to use this. Because this really shouldn't be used by others, this commit moves it into wireguard's noise.c locally, so that kernels that aren't using WireGuard don't get this superfluous code baked in. On m68k systems, this shaves off ~314 bytes. Cc: Herbert Xu <herbert@gondor.apana.org.au> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2020-09-09wireguard: noise: take lock when removing handshake entry from tableJason A. Donenfeld
Eric reported that syzkaller found a race of this variety: CPU 1 CPU 2 -------------------------------------------|--------------------------------------- wg_index_hashtable_replace(old, ...) | if (hlist_unhashed(&old->index_hash)) | | wg_index_hashtable_remove(old) | hlist_del_init_rcu(&old->index_hash) | old->index_hash.pprev = NULL hlist_replace_rcu(&old->index_hash, ...) | *old->index_hash.pprev | Syzbot wasn't actually able to reproduce this more than once or create a reproducer, because the race window between checking "hlist_unhashed" and calling "hlist_replace_rcu" is just so small. Adding an mdelay(5) or similar there helps make this demonstrable using this simple script: #!/bin/bash set -ex trap 'kill $pid1; kill $pid2; ip link del wg0; ip link del wg1' EXIT ip link add wg0 type wireguard ip link add wg1 type wireguard wg set wg0 private-key <(wg genkey) listen-port 9999 wg set wg1 private-key <(wg genkey) peer $(wg show wg0 public-key) endpoint 127.0.0.1:9999 persistent-keepalive 1 wg set wg0 peer $(wg show wg1 public-key) ip link set wg0 up yes link set wg1 up | ip -force -batch - & pid1=$! yes link set wg1 down | ip -force -batch - & pid2=$! wait The fundumental underlying problem is that we permit calls to wg_index_ hashtable_remove(handshake.entry) without requiring the caller to take the handshake mutex that is intended to protect members of handshake during mutations. This is consistently the case with calls to wg_index_ hashtable_insert(handshake.entry) and wg_index_hashtable_replace( handshake.entry), but it's missing from a pertinent callsite of wg_ index_hashtable_remove(handshake.entry). So, this patch makes sure that mutex is taken. The original code was a little bit funky though, in the form of: remove(handshake.entry) lock(), memzero(handshake.some_members), unlock() remove(handshake.entry) The original intention of that double removal pattern outside the lock appears to be some attempt to prevent insertions that might happen while locks are dropped during expensive crypto operations, but actually, all callers of wg_index_hashtable_insert(handshake.entry) take the write lock and then explicitly check handshake.state, as they should, which the aforementioned memzero clears, which means an insertion should already be impossible. And regardless, the original intention was necessarily racy, since it wasn't guaranteed that something else would run after the unlock() instead of after the remove(). So, from a soundness perspective, it seems positive to remove what looks like a hack at best. The crash from both syzbot and from the script above is as follows: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 PID: 7395 Comm: kworker/0:3 Not tainted 5.9.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: wg-kex-wg1 wg_packet_handshake_receive_worker RIP: 0010:hlist_replace_rcu include/linux/rculist.h:505 [inline] RIP: 0010:wg_index_hashtable_replace+0x176/0x330 drivers/net/wireguard/peerlookup.c:174 Code: 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c 01 00 0f 85 44 01 00 00 48 b9 00 00 00 00 00 fc ff df 48 8b 45 10 48 89 c6 48 c1 ee 03 <80> 3c 0e 00 0f 85 06 01 00 00 48 85 d2 4c 89 28 74 47 e8 a3 4f b5 RSP: 0018:ffffc90006a97bf8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff888050ffc4f8 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88808e04e010 RBP: ffff88808e04e000 R08: 0000000000000001 R09: ffff8880543d0000 R10: ffffed100a87a000 R11: 000000000000016e R12: ffff8880543d0000 R13: ffff88808e04e008 R14: ffff888050ffc508 R15: ffff888050ffc500 FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000f5505db0 CR3: 0000000097cf7000 CR4: 00000000001526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: wg_noise_handshake_begin_session+0x752/0xc9a drivers/net/wireguard/noise.c:820 wg_receive_handshake_packet drivers/net/wireguard/receive.c:183 [inline] wg_packet_handshake_receive_worker+0x33b/0x730 drivers/net/wireguard/receive.c:220 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Reported-by: syzbot <syzkaller@googlegroups.com> Reported-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/wireguard/20200908145911.4090480-1-edumazet@google.com/ 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>
2020-08-07mm, treewide: rename kzfree() to kfree_sensitive()Waiman Long
As said by Linus: A symmetric naming is only helpful if it implies symmetries in use. Otherwise it's actively misleading. In "kzalloc()", the z is meaningful and an important part of what the caller wants. In "kzfree()", the z is actively detrimental, because maybe in the future we really _might_ want to use that "memfill(0xdeadbeef)" or something. The "zero" part of the interface isn't even _relevant_. The main reason that kzfree() exists is to clear sensitive information that should not be leaked to other future users of the same memory objects. Rename kzfree() to kfree_sensitive() to follow the example of the recently added kvfree_sensitive() and make the intention of the API more explicit. In addition, memzero_explicit() is used to clear the memory to make sure that it won't get optimized away by the compiler. The renaming is done by using the command sequence: git grep -w --name-only kzfree |\ xargs sed -i 's/kzfree/kfree_sensitive/' followed by some editing of the kfree_sensitive() kerneldoc and adding a kzfree backward compatibility macro in slab.h. [akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h] [akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more] Suggested-by: Joe Perches <joe@perches.com> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: David Howells <dhowells@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Joe Perches <joe@perches.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: David Rientjes <rientjes@google.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: "Jason A . Donenfeld" <Jason@zx2c4.com> Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-23wireguard: noise: do not assign initiation time in if conditionFrank Werner-Krippendorf
Fixes an error condition reported by checkpatch.pl which caused by assigning a variable in an if condition in wg_noise_handshake_consume_ initiation(). Signed-off-by: Frank Werner-Krippendorf <mail@hb9fxq.ch> 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>
2020-05-20wireguard: noise: read preshared key while taking lockJason A. Donenfeld
Prior we read the preshared key after dropping the handshake lock, which isn't an actual crypto issue if it races, but it's still not quite correct. So copy that part of the state into a temporary like we do with the rest of the handshake state variables. Then we can release the lock, operate on the temporary, and zero it out at the end of the function. In performance tests, the impact of this was entirely unnoticable, probably because those bytes are coming from the same cacheline as other things that are being copied out in the same manner. Reported-by: Matt Dunwoodie <ncon@noconroy.net> 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>
2020-03-18wireguard: noise: error out precomputed DH during handshake rather than configJason A. Donenfeld
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 <mathias@hall-andersen.dk> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-05wireguard: noise: reject peers with low order public keysJason A. Donenfeld
Our static-static calculation returns a failure if the public key is of low order. We check for this when peers are added, and don't allow them to be added if they're low order, except in the case where we haven't yet been given a private key. In that case, we would defer the removal of the peer until we're given a private key, since at that point we're doing new static-static calculations which incur failures we can act on. This meant, however, that we wound up removing peers rather late in the configuration flow. Syzkaller points out that peer_remove calls flush_workqueue, which in turn might then wait for sending a handshake initiation to complete. Since handshake initiation needs the static identity lock, holding the static identity lock while calling peer_remove can result in a rare deadlock. We have precisely this case in this situation of late-stage peer removal based on an invalid public key. We can't drop the lock when removing, because then incoming handshakes might interact with a bogus static-static calculation. While the band-aid patch for this would involve breaking up the peer removal into two steps like wg_peer_remove_all does, in order to solve the locking issue, there's actually a much more elegant way of fixing this: If the static-static calculation succeeds with one private key, it *must* succeed with all others, because all 32-byte strings map to valid private keys, thanks to clamping. That means we can get rid of this silly dance and locking headaches of removing peers late in the configuration flow, and instead just reject them early on, regardless of whether the device has yet been assigned a private key. For the case where the device doesn't yet have a private key, we safely use zeros just for the purposes of checking for low order points by way of checking the output of the calculation. The following PoC will trigger the deadlock: ip link add wg0 type wireguard ip addr add 10.0.0.1/24 dev wg0 ip link set wg0 up ping -f 10.0.0.2 & while true; do wg set wg0 private-key /dev/null peer AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA= allowed-ips 10.0.0.0/24 endpoint 10.0.0.3:1234 wg set wg0 private-key <(echo AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=) done [ 0.949105] ====================================================== [ 0.949550] WARNING: possible circular locking dependency detected [ 0.950143] 5.5.0-debug+ #18 Not tainted [ 0.950431] ------------------------------------------------------ [ 0.950959] wg/89 is trying to acquire lock: [ 0.951252] ffff8880333e2128 ((wq_completion)wg-kex-wg0){+.+.}, at: flush_workqueue+0xe3/0x12f0 [ 0.951865] [ 0.951865] but task is already holding lock: [ 0.952280] ffff888032819bc0 (&wg->static_identity.lock){++++}, at: wg_set_device+0x95d/0xcc0 [ 0.953011] [ 0.953011] which lock already depends on the new lock. [ 0.953011] [ 0.953651] [ 0.953651] the existing dependency chain (in reverse order) is: [ 0.954292] [ 0.954292] -> #2 (&wg->static_identity.lock){++++}: [ 0.954804] lock_acquire+0x127/0x350 [ 0.955133] down_read+0x83/0x410 [ 0.955428] wg_noise_handshake_create_initiation+0x97/0x700 [ 0.955885] wg_packet_send_handshake_initiation+0x13a/0x280 [ 0.956401] wg_packet_handshake_send_worker+0x10/0x20 [ 0.956841] process_one_work+0x806/0x1500 [ 0.957167] worker_thread+0x8c/0xcb0 [ 0.957549] kthread+0x2ee/0x3b0 [ 0.957792] ret_from_fork+0x24/0x30 [ 0.958234] [ 0.958234] -> #1 ((work_completion)(&peer->transmit_handshake_work)){+.+.}: [ 0.958808] lock_acquire+0x127/0x350 [ 0.959075] process_one_work+0x7ab/0x1500 [ 0.959369] worker_thread+0x8c/0xcb0 [ 0.959639] kthread+0x2ee/0x3b0 [ 0.959896] ret_from_fork+0x24/0x30 [ 0.960346] [ 0.960346] -> #0 ((wq_completion)wg-kex-wg0){+.+.}: [ 0.960945] check_prev_add+0x167/0x1e20 [ 0.961351] __lock_acquire+0x2012/0x3170 [ 0.961725] lock_acquire+0x127/0x350 [ 0.961990] flush_workqueue+0x106/0x12f0 [ 0.962280] peer_remove_after_dead+0x160/0x220 [ 0.962600] wg_set_device+0xa24/0xcc0 [ 0.962994] genl_rcv_msg+0x52f/0xe90 [ 0.963298] netlink_rcv_skb+0x111/0x320 [ 0.963618] genl_rcv+0x1f/0x30 [ 0.963853] netlink_unicast+0x3f6/0x610 [ 0.964245] netlink_sendmsg+0x700/0xb80 [ 0.964586] __sys_sendto+0x1dd/0x2c0 [ 0.964854] __x64_sys_sendto+0xd8/0x1b0 [ 0.965141] do_syscall_64+0x90/0xd9a [ 0.965408] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 0.965769] [ 0.965769] other info that might help us debug this: [ 0.965769] [ 0.966337] Chain exists of: [ 0.966337] (wq_completion)wg-kex-wg0 --> (work_completion)(&peer->transmit_handshake_work) --> &wg->static_identity.lock [ 0.966337] [ 0.967417] Possible unsafe locking scenario: [ 0.967417] [ 0.967836] CPU0 CPU1 [ 0.968155] ---- ---- [ 0.968497] lock(&wg->static_identity.lock); [ 0.968779] lock((work_completion)(&peer->transmit_handshake_work)); [ 0.969345] lock(&wg->static_identity.lock); [ 0.969809] lock((wq_completion)wg-kex-wg0); [ 0.970146] [ 0.970146] *** DEADLOCK *** [ 0.970146] [ 0.970531] 5 locks held by wg/89: [ 0.970908] #0: ffffffff827433c8 (cb_lock){++++}, at: genl_rcv+0x10/0x30 [ 0.971400] #1: ffffffff82743480 (genl_mutex){+.+.}, at: genl_rcv_msg+0x642/0xe90 [ 0.971924] #2: ffffffff827160c0 (rtnl_mutex){+.+.}, at: wg_set_device+0x9f/0xcc0 [ 0.972488] #3: ffff888032819de0 (&wg->device_update_lock){+.+.}, at: wg_set_device+0xb0/0xcc0 [ 0.973095] #4: ffff888032819bc0 (&wg->static_identity.lock){++++}, at: wg_set_device+0x95d/0xcc0 [ 0.973653] [ 0.973653] stack backtrace: [ 0.973932] CPU: 1 PID: 89 Comm: wg Not tainted 5.5.0-debug+ #18 [ 0.974476] Call Trace: [ 0.974638] dump_stack+0x97/0xe0 [ 0.974869] check_noncircular+0x312/0x3e0 [ 0.975132] ? print_circular_bug+0x1f0/0x1f0 [ 0.975410] ? __kernel_text_address+0x9/0x30 [ 0.975727] ? unwind_get_return_address+0x51/0x90 [ 0.976024] check_prev_add+0x167/0x1e20 [ 0.976367] ? graph_lock+0x70/0x160 [ 0.976682] __lock_acquire+0x2012/0x3170 [ 0.976998] ? register_lock_class+0x1140/0x1140 [ 0.977323] lock_acquire+0x127/0x350 [ 0.977627] ? flush_workqueue+0xe3/0x12f0 [ 0.977890] flush_workqueue+0x106/0x12f0 [ 0.978147] ? flush_workqueue+0xe3/0x12f0 [ 0.978410] ? find_held_lock+0x2c/0x110 [ 0.978662] ? lock_downgrade+0x6e0/0x6e0 [ 0.978919] ? queue_rcu_work+0x60/0x60 [ 0.979166] ? netif_napi_del+0x151/0x3b0 [ 0.979501] ? peer_remove_after_dead+0x160/0x220 [ 0.979871] peer_remove_after_dead+0x160/0x220 [ 0.980232] wg_set_device+0xa24/0xcc0 [ 0.980516] ? deref_stack_reg+0x8e/0xc0 [ 0.980801] ? set_peer+0xe10/0xe10 [ 0.981040] ? __ww_mutex_check_waiters+0x150/0x150 [ 0.981430] ? __nla_validate_parse+0x163/0x270 [ 0.981719] ? genl_family_rcv_msg_attrs_parse+0x13f/0x310 [ 0.982078] genl_rcv_msg+0x52f/0xe90 [ 0.982348] ? genl_family_rcv_msg_attrs_parse+0x310/0x310 [ 0.982690] ? register_lock_class+0x1140/0x1140 [ 0.983049] netlink_rcv_skb+0x111/0x320 [ 0.983298] ? genl_family_rcv_msg_attrs_parse+0x310/0x310 [ 0.983645] ? netlink_ack+0x880/0x880 [ 0.983888] genl_rcv+0x1f/0x30 [ 0.984168] netlink_unicast+0x3f6/0x610 [ 0.984443] ? netlink_detachskb+0x60/0x60 [ 0.984729] ? find_held_lock+0x2c/0x110 [ 0.984976] netlink_sendmsg+0x700/0xb80 [ 0.985220] ? netlink_broadcast_filtered+0xa60/0xa60 [ 0.985533] __sys_sendto+0x1dd/0x2c0 [ 0.985763] ? __x64_sys_getpeername+0xb0/0xb0 [ 0.986039] ? sockfd_lookup_light+0x17/0x160 [ 0.986397] ? __sys_recvmsg+0x8c/0xf0 [ 0.986711] ? __sys_recvmsg_sock+0xd0/0xd0 [ 0.987018] __x64_sys_sendto+0xd8/0x1b0 [ 0.987283] ? lockdep_hardirqs_on+0x39b/0x5a0 [ 0.987666] do_syscall_64+0x90/0xd9a [ 0.987903] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 0.988223] RIP: 0033:0x7fe77c12003e [ 0.988508] Code: c3 8b 07 85 c0 75 24 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 4 [ 0.989666] RSP: 002b:00007fffada2ed58 EFLAGS: 00000246 ORIG_RAX: 000000000000002c [ 0.990137] RAX: ffffffffffffffda RBX: 00007fe77c159d48 RCX: 00007fe77c12003e [ 0.990583] RDX: 0000000000000040 RSI: 000055fd1d38e020 RDI: 0000000000000004 [ 0.991091] RBP: 000055fd1d38e020 R08: 000055fd1cb63358 R09: 000000000000000c [ 0.991568] R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000002c [ 0.992014] R13: 0000000000000004 R14: 000055fd1d38e020 R15: 0000000000000001 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Reported-by: syzbot <syzkaller@googlegroups.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>