| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. |
| */ |
| |
| #include "queueing.h" |
| #include "socket.h" |
| #include "timers.h" |
| #include "device.h" |
| #include "ratelimiter.h" |
| #include "peer.h" |
| #include "messages.h" |
| |
| #include <linux/module.h> |
| #include <linux/rtnetlink.h> |
| #include <linux/inet.h> |
| #include <linux/netdevice.h> |
| #include <linux/inetdevice.h> |
| #include <linux/if_arp.h> |
| #include <linux/icmp.h> |
| #include <linux/suspend.h> |
| #include <net/icmp.h> |
| #include <net/rtnetlink.h> |
| #include <net/ip_tunnels.h> |
| #include <net/addrconf.h> |
| |
| static LIST_HEAD(device_list); |
| |
| static int wg_open(struct net_device *dev) |
| { |
| struct in_device *dev_v4 = __in_dev_get_rtnl(dev); |
| struct inet6_dev *dev_v6 = __in6_dev_get(dev); |
| struct wg_device *wg = netdev_priv(dev); |
| struct wg_peer *peer; |
| int ret; |
| |
| if (dev_v4) { |
| /* At some point we might put this check near the ip_rt_send_ |
| * redirect call of ip_forward in net/ipv4/ip_forward.c, similar |
| * to the current secpath check. |
| */ |
| IN_DEV_CONF_SET(dev_v4, SEND_REDIRECTS, false); |
| IPV4_DEVCONF_ALL(dev_net(dev), SEND_REDIRECTS) = false; |
| } |
| if (dev_v6) |
| dev_v6->cnf.addr_gen_mode = IN6_ADDR_GEN_MODE_NONE; |
| |
| mutex_lock(&wg->device_update_lock); |
| ret = wg_socket_init(wg, wg->incoming_port); |
| if (ret < 0) |
| goto out; |
| list_for_each_entry(peer, &wg->peer_list, peer_list) { |
| wg_packet_send_staged_packets(peer); |
| if (peer->persistent_keepalive_interval) |
| wg_packet_send_keepalive(peer); |
| } |
| out: |
| mutex_unlock(&wg->device_update_lock); |
| return ret; |
| } |
| |
| static int wg_pm_notification(struct notifier_block *nb, unsigned long action, void *data) |
| { |
| struct wg_device *wg; |
| struct wg_peer *peer; |
| |
| /* If the machine is constantly suspending and resuming, as part of |
| * its normal operation rather than as a somewhat rare event, then we |
| * don't actually want to clear keys. |
| */ |
| if (IS_ENABLED(CONFIG_PM_AUTOSLEEP) || IS_ENABLED(CONFIG_ANDROID)) |
| return 0; |
| |
| if (action != PM_HIBERNATION_PREPARE && action != PM_SUSPEND_PREPARE) |
| return 0; |
| |
| rtnl_lock(); |
| list_for_each_entry(wg, &device_list, device_list) { |
| mutex_lock(&wg->device_update_lock); |
| list_for_each_entry(peer, &wg->peer_list, peer_list) { |
| del_timer(&peer->timer_zero_key_material); |
| wg_noise_handshake_clear(&peer->handshake); |
| wg_noise_keypairs_clear(&peer->keypairs); |
| } |
| mutex_unlock(&wg->device_update_lock); |
| } |
| rtnl_unlock(); |
| rcu_barrier(); |
| return 0; |
| } |
| |
| static struct notifier_block pm_notifier = { .notifier_call = wg_pm_notification }; |
| |
| static int wg_vm_notification(struct notifier_block *nb, unsigned long action, void *data) |
| { |
| struct wg_device *wg; |
| struct wg_peer *peer; |
| |
| rtnl_lock(); |
| list_for_each_entry(wg, &device_list, device_list) { |
| mutex_lock(&wg->device_update_lock); |
| list_for_each_entry(peer, &wg->peer_list, peer_list) |
| wg_noise_expire_current_peer_keypairs(peer); |
| mutex_unlock(&wg->device_update_lock); |
| } |
| rtnl_unlock(); |
| return 0; |
| } |
| |
| static struct notifier_block vm_notifier = { .notifier_call = wg_vm_notification }; |
| |
| static int wg_stop(struct net_device *dev) |
| { |
| struct wg_device *wg = netdev_priv(dev); |
| struct wg_peer *peer; |
| struct sk_buff *skb; |
| |
| mutex_lock(&wg->device_update_lock); |
| list_for_each_entry(peer, &wg->peer_list, peer_list) { |
| wg_packet_purge_staged_packets(peer); |
| wg_timers_stop(peer); |
| wg_noise_handshake_clear(&peer->handshake); |
| wg_noise_keypairs_clear(&peer->keypairs); |
| wg_noise_reset_last_sent_handshake(&peer->last_sent_handshake); |
| } |
| mutex_unlock(&wg->device_update_lock); |
| while ((skb = ptr_ring_consume(&wg->handshake_queue.ring)) != NULL) |
| kfree_skb(skb); |
| atomic_set(&wg->handshake_queue_len, 0); |
| wg_socket_reinit(wg, NULL, NULL); |
| return 0; |
| } |
| |
| static netdev_tx_t wg_xmit(struct sk_buff *skb, struct net_device *dev) |
| { |
| struct wg_device *wg = netdev_priv(dev); |
| struct sk_buff_head packets; |
| struct wg_peer *peer; |
| struct sk_buff *next; |
| sa_family_t family; |
| u32 mtu; |
| int ret; |
| |
| if (unlikely(!wg_check_packet_protocol(skb))) { |
| ret = -EPROTONOSUPPORT; |
| net_dbg_ratelimited("%s: Invalid IP packet\n", dev->name); |
| goto err; |
| } |
| |
| peer = wg_allowedips_lookup_dst(&wg->peer_allowedips, skb); |
| if (unlikely(!peer)) { |
| ret = -ENOKEY; |
| if (skb->protocol == htons(ETH_P_IP)) |
| net_dbg_ratelimited("%s: No peer has allowed IPs matching %pI4\n", |
| dev->name, &ip_hdr(skb)->daddr); |
| else if (skb->protocol == htons(ETH_P_IPV6)) |
| net_dbg_ratelimited("%s: No peer has allowed IPs matching %pI6\n", |
| dev->name, &ipv6_hdr(skb)->daddr); |
| goto err_icmp; |
| } |
| |
| family = READ_ONCE(peer->endpoint.addr.sa_family); |
| if (unlikely(family != AF_INET && family != AF_INET6)) { |
| ret = -EDESTADDRREQ; |
| net_dbg_ratelimited("%s: No valid endpoint has been configured or discovered for peer %llu\n", |
| dev->name, peer->internal_id); |
| goto err_peer; |
| } |
| |
| mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu; |
| |
| __skb_queue_head_init(&packets); |
| if (!skb_is_gso(skb)) { |
| skb_mark_not_on_list(skb); |
| } else { |
| struct sk_buff *segs = skb_gso_segment(skb, 0); |
| |
| if (IS_ERR(segs)) { |
| ret = PTR_ERR(segs); |
| goto err_peer; |
| } |
| dev_kfree_skb(skb); |
| skb = segs; |
| } |
| |
| skb_list_walk_safe(skb, skb, next) { |
| skb_mark_not_on_list(skb); |
| |
| skb = skb_share_check(skb, GFP_ATOMIC); |
| if (unlikely(!skb)) |
| continue; |
| |
| /* We only need to keep the original dst around for icmp, |
| * so at this point we're in a position to drop it. |
| */ |
| skb_dst_drop(skb); |
| |
| PACKET_CB(skb)->mtu = mtu; |
| |
| __skb_queue_tail(&packets, skb); |
| } |
| |
| spin_lock_bh(&peer->staged_packet_queue.lock); |
| /* If the queue is getting too big, we start removing the oldest packets |
| * until it's small again. We do this before adding the new packet, so |
| * we don't remove GSO segments that are in excess. |
| */ |
| while (skb_queue_len(&peer->staged_packet_queue) > MAX_STAGED_PACKETS) { |
| dev_kfree_skb(__skb_dequeue(&peer->staged_packet_queue)); |
| ++dev->stats.tx_dropped; |
| } |
| skb_queue_splice_tail(&packets, &peer->staged_packet_queue); |
| spin_unlock_bh(&peer->staged_packet_queue.lock); |
| |
| wg_packet_send_staged_packets(peer); |
| |
| wg_peer_put(peer); |
| return NETDEV_TX_OK; |
| |
| err_peer: |
| wg_peer_put(peer); |
| err_icmp: |
| if (skb->protocol == htons(ETH_P_IP)) |
| icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0); |
| else if (skb->protocol == htons(ETH_P_IPV6)) |
| icmpv6_ndo_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0); |
| err: |
| ++dev->stats.tx_errors; |
| kfree_skb(skb); |
| return ret; |
| } |
| |
| static const struct net_device_ops netdev_ops = { |
| .ndo_open = wg_open, |
| .ndo_stop = wg_stop, |
| .ndo_start_xmit = wg_xmit, |
| .ndo_get_stats64 = dev_get_tstats64 |
| }; |
| |
| static void wg_destruct(struct net_device *dev) |
| { |
| struct wg_device *wg = netdev_priv(dev); |
| |
| rtnl_lock(); |
| list_del(&wg->device_list); |
| rtnl_unlock(); |
| mutex_lock(&wg->device_update_lock); |
| rcu_assign_pointer(wg->creating_net, NULL); |
| wg->incoming_port = 0; |
| wg_socket_reinit(wg, NULL, NULL); |
| /* The final references are cleared in the below calls to destroy_workqueue. */ |
| wg_peer_remove_all(wg); |
| destroy_workqueue(wg->handshake_receive_wq); |
| destroy_workqueue(wg->handshake_send_wq); |
| destroy_workqueue(wg->packet_crypt_wq); |
| wg_packet_queue_free(&wg->handshake_queue, true); |
| wg_packet_queue_free(&wg->decrypt_queue, false); |
| wg_packet_queue_free(&wg->encrypt_queue, false); |
| rcu_barrier(); /* Wait for all the peers to be actually freed. */ |
| wg_ratelimiter_uninit(); |
| memzero_explicit(&wg->static_identity, sizeof(wg->static_identity)); |
| free_percpu(dev->tstats); |
| kvfree(wg->index_hashtable); |
| kvfree(wg->peer_hashtable); |
| mutex_unlock(&wg->device_update_lock); |
| |
| pr_debug("%s: Interface destroyed\n", dev->name); |
| free_netdev(dev); |
| } |
| |
| static const struct device_type device_type = { .name = KBUILD_MODNAME }; |
| |
| static void wg_setup(struct net_device *dev) |
| { |
| struct wg_device *wg = netdev_priv(dev); |
| enum { WG_NETDEV_FEATURES = NETIF_F_HW_CSUM | NETIF_F_RXCSUM | |
| NETIF_F_SG | NETIF_F_GSO | |
| NETIF_F_GSO_SOFTWARE | NETIF_F_HIGHDMA }; |
| const int overhead = MESSAGE_MINIMUM_LENGTH + sizeof(struct udphdr) + |
| max(sizeof(struct ipv6hdr), sizeof(struct iphdr)); |
| |
| dev->netdev_ops = &netdev_ops; |
| dev->header_ops = &ip_tunnel_header_ops; |
| dev->hard_header_len = 0; |
| dev->addr_len = 0; |
| dev->needed_headroom = DATA_PACKET_HEAD_ROOM; |
| dev->needed_tailroom = noise_encrypted_len(MESSAGE_PADDING_MULTIPLE); |
| dev->type = ARPHRD_NONE; |
| dev->flags = IFF_POINTOPOINT | IFF_NOARP; |
| dev->priv_flags |= IFF_NO_QUEUE; |
| dev->features |= NETIF_F_LLTX; |
| dev->features |= WG_NETDEV_FEATURES; |
| dev->hw_features |= WG_NETDEV_FEATURES; |
| dev->hw_enc_features |= WG_NETDEV_FEATURES; |
| dev->mtu = ETH_DATA_LEN - overhead; |
| dev->max_mtu = round_down(INT_MAX, MESSAGE_PADDING_MULTIPLE) - overhead; |
| |
| SET_NETDEV_DEVTYPE(dev, &device_type); |
| |
| /* We need to keep the dst around in case of icmp replies. */ |
| netif_keep_dst(dev); |
| |
| memset(wg, 0, sizeof(*wg)); |
| wg->dev = dev; |
| } |
| |
| static int wg_newlink(struct net *src_net, struct net_device *dev, |
| struct nlattr *tb[], struct nlattr *data[], |
| struct netlink_ext_ack *extack) |
| { |
| struct wg_device *wg = netdev_priv(dev); |
| int ret = -ENOMEM; |
| |
| rcu_assign_pointer(wg->creating_net, src_net); |
| init_rwsem(&wg->static_identity.lock); |
| mutex_init(&wg->socket_update_lock); |
| mutex_init(&wg->device_update_lock); |
| wg_allowedips_init(&wg->peer_allowedips); |
| wg_cookie_checker_init(&wg->cookie_checker, wg); |
| INIT_LIST_HEAD(&wg->peer_list); |
| wg->device_update_gen = 1; |
| |
| wg->peer_hashtable = wg_pubkey_hashtable_alloc(); |
| if (!wg->peer_hashtable) |
| return ret; |
| |
| wg->index_hashtable = wg_index_hashtable_alloc(); |
| if (!wg->index_hashtable) |
| goto err_free_peer_hashtable; |
| |
| dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); |
| if (!dev->tstats) |
| goto err_free_index_hashtable; |
| |
| wg->handshake_receive_wq = alloc_workqueue("wg-kex-%s", |
| WQ_CPU_INTENSIVE | WQ_FREEZABLE, 0, dev->name); |
| if (!wg->handshake_receive_wq) |
| goto err_free_tstats; |
| |
| wg->handshake_send_wq = alloc_workqueue("wg-kex-%s", |
| WQ_UNBOUND | WQ_FREEZABLE, 0, dev->name); |
| if (!wg->handshake_send_wq) |
| goto err_destroy_handshake_receive; |
| |
| wg->packet_crypt_wq = alloc_workqueue("wg-crypt-%s", |
| WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 0, dev->name); |
| if (!wg->packet_crypt_wq) |
| goto err_destroy_handshake_send; |
| |
| ret = wg_packet_queue_init(&wg->encrypt_queue, wg_packet_encrypt_worker, |
| MAX_QUEUED_PACKETS); |
| if (ret < 0) |
| goto err_destroy_packet_crypt; |
| |
| ret = wg_packet_queue_init(&wg->decrypt_queue, wg_packet_decrypt_worker, |
| MAX_QUEUED_PACKETS); |
| if (ret < 0) |
| goto err_free_encrypt_queue; |
| |
| ret = wg_packet_queue_init(&wg->handshake_queue, wg_packet_handshake_receive_worker, |
| MAX_QUEUED_INCOMING_HANDSHAKES); |
| if (ret < 0) |
| goto err_free_decrypt_queue; |
| |
| ret = wg_ratelimiter_init(); |
| if (ret < 0) |
| goto err_free_handshake_queue; |
| |
| ret = register_netdevice(dev); |
| if (ret < 0) |
| goto err_uninit_ratelimiter; |
| |
| list_add(&wg->device_list, &device_list); |
| |
| /* We wait until the end to assign priv_destructor, so that |
| * register_netdevice doesn't call it for us if it fails. |
| */ |
| dev->priv_destructor = wg_destruct; |
| |
| pr_debug("%s: Interface created\n", dev->name); |
| return ret; |
| |
| err_uninit_ratelimiter: |
| wg_ratelimiter_uninit(); |
| err_free_handshake_queue: |
| wg_packet_queue_free(&wg->handshake_queue, false); |
| err_free_decrypt_queue: |
| wg_packet_queue_free(&wg->decrypt_queue, false); |
| err_free_encrypt_queue: |
| wg_packet_queue_free(&wg->encrypt_queue, false); |
| err_destroy_packet_crypt: |
| destroy_workqueue(wg->packet_crypt_wq); |
| err_destroy_handshake_send: |
| destroy_workqueue(wg->handshake_send_wq); |
| err_destroy_handshake_receive: |
| destroy_workqueue(wg->handshake_receive_wq); |
| err_free_tstats: |
| free_percpu(dev->tstats); |
| err_free_index_hashtable: |
| kvfree(wg->index_hashtable); |
| err_free_peer_hashtable: |
| kvfree(wg->peer_hashtable); |
| return ret; |
| } |
| |
| static struct rtnl_link_ops link_ops __read_mostly = { |
| .kind = KBUILD_MODNAME, |
| .priv_size = sizeof(struct wg_device), |
| .setup = wg_setup, |
| .newlink = wg_newlink, |
| }; |
| |
| static void wg_netns_pre_exit(struct net *net) |
| { |
| struct wg_device *wg; |
| struct wg_peer *peer; |
| |
| rtnl_lock(); |
| list_for_each_entry(wg, &device_list, device_list) { |
| if (rcu_access_pointer(wg->creating_net) == net) { |
| pr_debug("%s: Creating namespace exiting\n", wg->dev->name); |
| netif_carrier_off(wg->dev); |
| mutex_lock(&wg->device_update_lock); |
| rcu_assign_pointer(wg->creating_net, NULL); |
| wg_socket_reinit(wg, NULL, NULL); |
| list_for_each_entry(peer, &wg->peer_list, peer_list) |
| wg_socket_clear_peer_endpoint_src(peer); |
| mutex_unlock(&wg->device_update_lock); |
| } |
| } |
| rtnl_unlock(); |
| } |
| |
| static struct pernet_operations pernet_ops = { |
| .pre_exit = wg_netns_pre_exit |
| }; |
| |
| int __init wg_device_init(void) |
| { |
| int ret; |
| |
| ret = register_pm_notifier(&pm_notifier); |
| if (ret) |
| return ret; |
| |
| ret = register_random_vmfork_notifier(&vm_notifier); |
| if (ret) |
| goto error_pm; |
| |
| ret = register_pernet_device(&pernet_ops); |
| if (ret) |
| goto error_vm; |
| |
| ret = rtnl_link_register(&link_ops); |
| if (ret) |
| goto error_pernet; |
| |
| return 0; |
| |
| error_pernet: |
| unregister_pernet_device(&pernet_ops); |
| error_vm: |
| unregister_random_vmfork_notifier(&vm_notifier); |
| error_pm: |
| unregister_pm_notifier(&pm_notifier); |
| return ret; |
| } |
| |
| void wg_device_uninit(void) |
| { |
| rtnl_link_unregister(&link_ops); |
| unregister_pernet_device(&pernet_ops); |
| unregister_random_vmfork_notifier(&vm_notifier); |
| unregister_pm_notifier(&pm_notifier); |
| rcu_barrier(); |
| } |