1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
10 #include "ratelimiter.h"
14 #include <linux/module.h>
15 #include <linux/rtnetlink.h>
16 #include <linux/inet.h>
17 #include <linux/netdevice.h>
18 #include <linux/inetdevice.h>
19 #include <linux/if_arp.h>
20 #include <linux/icmp.h>
21 #include <linux/suspend.h>
23 #include <net/rtnetlink.h>
24 #include <net/ip_tunnels.h>
25 #include <net/addrconf.h>
27 static LIST_HEAD(device_list);
29 static int wg_open(struct net_device *dev)
31 struct in_device *dev_v4 = __in_dev_get_rtnl(dev);
32 struct inet6_dev *dev_v6 = __in6_dev_get(dev);
33 struct wg_device *wg = netdev_priv(dev);
38 /* At some point we might put this check near the ip_rt_send_
39 * redirect call of ip_forward in net/ipv4/ip_forward.c, similar
40 * to the current secpath check.
42 IN_DEV_CONF_SET(dev_v4, SEND_REDIRECTS, false);
43 IPV4_DEVCONF_ALL(dev_net(dev), SEND_REDIRECTS) = false;
46 dev_v6->cnf.addr_gen_mode = IN6_ADDR_GEN_MODE_NONE;
48 mutex_lock(&wg->device_update_lock);
49 ret = wg_socket_init(wg, wg->incoming_port);
52 list_for_each_entry(peer, &wg->peer_list, peer_list) {
53 wg_packet_send_staged_packets(peer);
54 if (peer->persistent_keepalive_interval)
55 wg_packet_send_keepalive(peer);
58 mutex_unlock(&wg->device_update_lock);
62 #ifdef CONFIG_PM_SLEEP
63 static int wg_pm_notification(struct notifier_block *nb, unsigned long action,
69 /* If the machine is constantly suspending and resuming, as part of
70 * its normal operation rather than as a somewhat rare event, then we
71 * don't actually want to clear keys.
73 if (IS_ENABLED(CONFIG_PM_AUTOSLEEP) || IS_ENABLED(CONFIG_ANDROID))
76 if (action != PM_HIBERNATION_PREPARE && action != PM_SUSPEND_PREPARE)
80 list_for_each_entry(wg, &device_list, device_list) {
81 mutex_lock(&wg->device_update_lock);
82 list_for_each_entry(peer, &wg->peer_list, peer_list) {
83 del_timer(&peer->timer_zero_key_material);
84 wg_noise_handshake_clear(&peer->handshake);
85 wg_noise_keypairs_clear(&peer->keypairs);
87 mutex_unlock(&wg->device_update_lock);
94 static struct notifier_block pm_notifier = { .notifier_call = wg_pm_notification };
97 static int wg_stop(struct net_device *dev)
99 struct wg_device *wg = netdev_priv(dev);
100 struct wg_peer *peer;
102 mutex_lock(&wg->device_update_lock);
103 list_for_each_entry(peer, &wg->peer_list, peer_list) {
104 wg_packet_purge_staged_packets(peer);
105 wg_timers_stop(peer);
106 wg_noise_handshake_clear(&peer->handshake);
107 wg_noise_keypairs_clear(&peer->keypairs);
108 wg_noise_reset_last_sent_handshake(&peer->last_sent_handshake);
110 mutex_unlock(&wg->device_update_lock);
111 skb_queue_purge(&wg->incoming_handshakes);
112 wg_socket_reinit(wg, NULL, NULL);
116 static netdev_tx_t wg_xmit(struct sk_buff *skb, struct net_device *dev)
118 struct wg_device *wg = netdev_priv(dev);
119 struct sk_buff_head packets;
120 struct wg_peer *peer;
121 struct sk_buff *next;
126 if (unlikely(!wg_check_packet_protocol(skb))) {
127 ret = -EPROTONOSUPPORT;
128 net_dbg_ratelimited("%s: Invalid IP packet\n", dev->name);
132 peer = wg_allowedips_lookup_dst(&wg->peer_allowedips, skb);
133 if (unlikely(!peer)) {
135 if (skb->protocol == htons(ETH_P_IP))
136 net_dbg_ratelimited("%s: No peer has allowed IPs matching %pI4\n",
137 dev->name, &ip_hdr(skb)->daddr);
138 else if (skb->protocol == htons(ETH_P_IPV6))
139 net_dbg_ratelimited("%s: No peer has allowed IPs matching %pI6\n",
140 dev->name, &ipv6_hdr(skb)->daddr);
144 family = READ_ONCE(peer->endpoint.addr.sa_family);
145 if (unlikely(family != AF_INET && family != AF_INET6)) {
147 net_dbg_ratelimited("%s: No valid endpoint has been configured or discovered for peer %llu\n",
148 dev->name, peer->internal_id);
152 mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
154 __skb_queue_head_init(&packets);
155 if (!skb_is_gso(skb)) {
156 skb_mark_not_on_list(skb);
158 struct sk_buff *segs = skb_gso_segment(skb, 0);
168 skb_list_walk_safe(skb, skb, next) {
169 skb_mark_not_on_list(skb);
171 skb = skb_share_check(skb, GFP_ATOMIC);
175 /* We only need to keep the original dst around for icmp,
176 * so at this point we're in a position to drop it.
180 PACKET_CB(skb)->mtu = mtu;
182 __skb_queue_tail(&packets, skb);
185 spin_lock_bh(&peer->staged_packet_queue.lock);
186 /* If the queue is getting too big, we start removing the oldest packets
187 * until it's small again. We do this before adding the new packet, so
188 * we don't remove GSO segments that are in excess.
190 while (skb_queue_len(&peer->staged_packet_queue) > MAX_STAGED_PACKETS) {
191 dev_kfree_skb(__skb_dequeue(&peer->staged_packet_queue));
192 ++dev->stats.tx_dropped;
194 skb_queue_splice_tail(&packets, &peer->staged_packet_queue);
195 spin_unlock_bh(&peer->staged_packet_queue.lock);
197 wg_packet_send_staged_packets(peer);
205 if (skb->protocol == htons(ETH_P_IP))
206 icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
207 else if (skb->protocol == htons(ETH_P_IPV6))
208 icmpv6_ndo_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
210 ++dev->stats.tx_errors;
215 static const struct net_device_ops netdev_ops = {
218 .ndo_start_xmit = wg_xmit,
219 .ndo_get_stats64 = dev_get_tstats64
222 static void wg_destruct(struct net_device *dev)
224 struct wg_device *wg = netdev_priv(dev);
227 list_del(&wg->device_list);
229 mutex_lock(&wg->device_update_lock);
230 rcu_assign_pointer(wg->creating_net, NULL);
231 wg->incoming_port = 0;
232 wg_socket_reinit(wg, NULL, NULL);
233 /* The final references are cleared in the below calls to destroy_workqueue. */
234 wg_peer_remove_all(wg);
235 destroy_workqueue(wg->handshake_receive_wq);
236 destroy_workqueue(wg->handshake_send_wq);
237 destroy_workqueue(wg->packet_crypt_wq);
238 wg_packet_queue_free(&wg->decrypt_queue);
239 wg_packet_queue_free(&wg->encrypt_queue);
240 rcu_barrier(); /* Wait for all the peers to be actually freed. */
241 wg_ratelimiter_uninit();
242 memzero_explicit(&wg->static_identity, sizeof(wg->static_identity));
243 skb_queue_purge(&wg->incoming_handshakes);
244 free_percpu(dev->tstats);
245 free_percpu(wg->incoming_handshakes_worker);
246 kvfree(wg->index_hashtable);
247 kvfree(wg->peer_hashtable);
248 mutex_unlock(&wg->device_update_lock);
250 pr_debug("%s: Interface destroyed\n", dev->name);
254 static const struct device_type device_type = { .name = KBUILD_MODNAME };
256 static void wg_setup(struct net_device *dev)
258 struct wg_device *wg = netdev_priv(dev);
259 enum { WG_NETDEV_FEATURES = NETIF_F_HW_CSUM | NETIF_F_RXCSUM |
260 NETIF_F_SG | NETIF_F_GSO |
261 NETIF_F_GSO_SOFTWARE | NETIF_F_HIGHDMA };
262 const int overhead = MESSAGE_MINIMUM_LENGTH + sizeof(struct udphdr) +
263 max(sizeof(struct ipv6hdr), sizeof(struct iphdr));
265 dev->netdev_ops = &netdev_ops;
266 dev->header_ops = &ip_tunnel_header_ops;
267 dev->hard_header_len = 0;
269 dev->needed_headroom = DATA_PACKET_HEAD_ROOM;
270 dev->needed_tailroom = noise_encrypted_len(MESSAGE_PADDING_MULTIPLE);
271 dev->type = ARPHRD_NONE;
272 dev->flags = IFF_POINTOPOINT | IFF_NOARP;
273 dev->priv_flags |= IFF_NO_QUEUE;
274 dev->features |= NETIF_F_LLTX;
275 dev->features |= WG_NETDEV_FEATURES;
276 dev->hw_features |= WG_NETDEV_FEATURES;
277 dev->hw_enc_features |= WG_NETDEV_FEATURES;
278 dev->mtu = ETH_DATA_LEN - overhead;
279 dev->max_mtu = round_down(INT_MAX, MESSAGE_PADDING_MULTIPLE) - overhead;
281 SET_NETDEV_DEVTYPE(dev, &device_type);
283 /* We need to keep the dst around in case of icmp replies. */
286 memset(wg, 0, sizeof(*wg));
290 static int wg_newlink(struct net *src_net, struct net_device *dev,
291 struct nlattr *tb[], struct nlattr *data[],
292 struct netlink_ext_ack *extack)
294 struct wg_device *wg = netdev_priv(dev);
297 rcu_assign_pointer(wg->creating_net, src_net);
298 init_rwsem(&wg->static_identity.lock);
299 mutex_init(&wg->socket_update_lock);
300 mutex_init(&wg->device_update_lock);
301 skb_queue_head_init(&wg->incoming_handshakes);
302 wg_allowedips_init(&wg->peer_allowedips);
303 wg_cookie_checker_init(&wg->cookie_checker, wg);
304 INIT_LIST_HEAD(&wg->peer_list);
305 wg->device_update_gen = 1;
307 wg->peer_hashtable = wg_pubkey_hashtable_alloc();
308 if (!wg->peer_hashtable)
311 wg->index_hashtable = wg_index_hashtable_alloc();
312 if (!wg->index_hashtable)
313 goto err_free_peer_hashtable;
315 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
317 goto err_free_index_hashtable;
319 wg->incoming_handshakes_worker =
320 wg_packet_percpu_multicore_worker_alloc(
321 wg_packet_handshake_receive_worker, wg);
322 if (!wg->incoming_handshakes_worker)
323 goto err_free_tstats;
325 wg->handshake_receive_wq = alloc_workqueue("wg-kex-%s",
326 WQ_CPU_INTENSIVE | WQ_FREEZABLE, 0, dev->name);
327 if (!wg->handshake_receive_wq)
328 goto err_free_incoming_handshakes;
330 wg->handshake_send_wq = alloc_workqueue("wg-kex-%s",
331 WQ_UNBOUND | WQ_FREEZABLE, 0, dev->name);
332 if (!wg->handshake_send_wq)
333 goto err_destroy_handshake_receive;
335 wg->packet_crypt_wq = alloc_workqueue("wg-crypt-%s",
336 WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 0, dev->name);
337 if (!wg->packet_crypt_wq)
338 goto err_destroy_handshake_send;
340 ret = wg_packet_queue_init(&wg->encrypt_queue, wg_packet_encrypt_worker,
343 goto err_destroy_packet_crypt;
345 ret = wg_packet_queue_init(&wg->decrypt_queue, wg_packet_decrypt_worker,
348 goto err_free_encrypt_queue;
350 ret = wg_ratelimiter_init();
352 goto err_free_decrypt_queue;
354 ret = register_netdevice(dev);
356 goto err_uninit_ratelimiter;
358 list_add(&wg->device_list, &device_list);
360 /* We wait until the end to assign priv_destructor, so that
361 * register_netdevice doesn't call it for us if it fails.
363 dev->priv_destructor = wg_destruct;
365 pr_debug("%s: Interface created\n", dev->name);
368 err_uninit_ratelimiter:
369 wg_ratelimiter_uninit();
370 err_free_decrypt_queue:
371 wg_packet_queue_free(&wg->decrypt_queue);
372 err_free_encrypt_queue:
373 wg_packet_queue_free(&wg->encrypt_queue);
374 err_destroy_packet_crypt:
375 destroy_workqueue(wg->packet_crypt_wq);
376 err_destroy_handshake_send:
377 destroy_workqueue(wg->handshake_send_wq);
378 err_destroy_handshake_receive:
379 destroy_workqueue(wg->handshake_receive_wq);
380 err_free_incoming_handshakes:
381 free_percpu(wg->incoming_handshakes_worker);
383 free_percpu(dev->tstats);
384 err_free_index_hashtable:
385 kvfree(wg->index_hashtable);
386 err_free_peer_hashtable:
387 kvfree(wg->peer_hashtable);
391 static struct rtnl_link_ops link_ops __read_mostly = {
392 .kind = KBUILD_MODNAME,
393 .priv_size = sizeof(struct wg_device),
395 .newlink = wg_newlink,
398 static void wg_netns_pre_exit(struct net *net)
400 struct wg_device *wg;
403 list_for_each_entry(wg, &device_list, device_list) {
404 if (rcu_access_pointer(wg->creating_net) == net) {
405 pr_debug("%s: Creating namespace exiting\n", wg->dev->name);
406 netif_carrier_off(wg->dev);
407 mutex_lock(&wg->device_update_lock);
408 rcu_assign_pointer(wg->creating_net, NULL);
409 wg_socket_reinit(wg, NULL, NULL);
410 mutex_unlock(&wg->device_update_lock);
416 static struct pernet_operations pernet_ops = {
417 .pre_exit = wg_netns_pre_exit
420 int __init wg_device_init(void)
424 #ifdef CONFIG_PM_SLEEP
425 ret = register_pm_notifier(&pm_notifier);
430 ret = register_pernet_device(&pernet_ops);
434 ret = rtnl_link_register(&link_ops);
441 unregister_pernet_device(&pernet_ops);
443 #ifdef CONFIG_PM_SLEEP
444 unregister_pm_notifier(&pm_notifier);
449 void wg_device_uninit(void)
451 rtnl_link_unregister(&link_ops);
452 unregister_pernet_device(&pernet_ops);
453 #ifdef CONFIG_PM_SLEEP
454 unregister_pm_notifier(&pm_notifier);