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Diffstat (limited to 'drivers/net/wireguard/device.c')
-rw-r--r--drivers/net/wireguard/device.c460
1 files changed, 460 insertions, 0 deletions
diff --git a/drivers/net/wireguard/device.c b/drivers/net/wireguard/device.c
new file mode 100644
index 000000000000..fd23189419da
--- /dev/null
+++ b/drivers/net/wireguard/device.c
@@ -0,0 +1,460 @@
+// 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;
+
+ ret = wg_socket_init(wg, wg->incoming_port);
+ if (ret < 0)
+ return ret;
+ mutex_lock(&wg->device_update_lock);
+ 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);
+ }
+ mutex_unlock(&wg->device_update_lock);
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+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 };
+#endif
+
+static int wg_stop(struct net_device *dev)
+{
+ struct wg_device *wg = netdev_priv(dev);
+ struct wg_peer *peer;
+
+ 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);
+ atomic64_set(&peer->last_sent_handshake,
+ ktime_get_boot_fast_ns() -
+ (u64)(REKEY_TIMEOUT + 1) * NSEC_PER_SEC);
+ }
+ mutex_unlock(&wg->device_update_lock);
+ skb_queue_purge(&wg->incoming_handshakes);
+ 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_skb_examine_untrusted_ip_hdr(skb) != skb->protocol)) {
+ 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;
+ }
+
+ 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 (unlikely(IS_ERR(segs))) {
+ ret = PTR_ERR(segs);
+ goto err_peer;
+ }
+ dev_kfree_skb(skb);
+ skb = segs;
+ }
+ do {
+ next = 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);
+ } while ((skb = next) != NULL);
+
+ 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:
+ ++dev->stats.tx_errors;
+ if (skb->protocol == htons(ETH_P_IP))
+ icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
+ else if (skb->protocol == htons(ETH_P_IPV6))
+ icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
+ 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 = ip_tunnel_get_stats64
+};
+
+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);
+ 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->decrypt_queue, true);
+ wg_packet_queue_free(&wg->encrypt_queue, true);
+ rcu_barrier(); /* Wait for all the peers to be actually freed. */
+ wg_ratelimiter_uninit();
+ memzero_explicit(&wg->static_identity, sizeof(wg->static_identity));
+ skb_queue_purge(&wg->incoming_handshakes);
+ free_percpu(dev->tstats);
+ free_percpu(wg->incoming_handshakes_worker);
+ if (wg->have_creating_net_ref)
+ put_net(wg->creating_net);
+ kvfree(wg->index_hashtable);
+ kvfree(wg->peer_hashtable);
+ mutex_unlock(&wg->device_update_lock);
+
+ pr_debug("%s: Interface deleted\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 };
+
+ dev->netdev_ops = &netdev_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 - MESSAGE_MINIMUM_LENGTH -
+ sizeof(struct udphdr) -
+ max(sizeof(struct ipv6hdr), sizeof(struct iphdr));
+
+ 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;
+
+ wg->creating_net = src_net;
+ init_rwsem(&wg->static_identity.lock);
+ mutex_init(&wg->socket_update_lock);
+ mutex_init(&wg->device_update_lock);
+ skb_queue_head_init(&wg->incoming_handshakes);
+ 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->incoming_handshakes_worker =
+ wg_packet_percpu_multicore_worker_alloc(
+ wg_packet_handshake_receive_worker, wg);
+ if (!wg->incoming_handshakes_worker)
+ goto err_free_tstats;
+
+ 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_incoming_handshakes;
+
+ 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,
+ true, MAX_QUEUED_PACKETS);
+ if (ret < 0)
+ goto err_destroy_packet_crypt;
+
+ ret = wg_packet_queue_init(&wg->decrypt_queue, wg_packet_decrypt_worker,
+ true, MAX_QUEUED_PACKETS);
+ if (ret < 0)
+ goto err_free_encrypt_queue;
+
+ ret = wg_ratelimiter_init();
+ if (ret < 0)
+ goto err_free_decrypt_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_decrypt_queue:
+ wg_packet_queue_free(&wg->decrypt_queue, true);
+err_free_encrypt_queue:
+ wg_packet_queue_free(&wg->encrypt_queue, true);
+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_incoming_handshakes:
+ free_percpu(wg->incoming_handshakes_worker);
+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 int wg_netdevice_notification(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct net_device *dev = ((struct netdev_notifier_info *)data)->dev;
+ struct wg_device *wg = netdev_priv(dev);
+
+ ASSERT_RTNL();
+
+ if (action != NETDEV_REGISTER || dev->netdev_ops != &netdev_ops)
+ return 0;
+
+ if (dev_net(dev) == wg->creating_net && wg->have_creating_net_ref) {
+ put_net(wg->creating_net);
+ wg->have_creating_net_ref = false;
+ } else if (dev_net(dev) != wg->creating_net &&
+ !wg->have_creating_net_ref) {
+ wg->have_creating_net_ref = true;
+ get_net(wg->creating_net);
+ }
+ return 0;
+}
+
+static struct notifier_block netdevice_notifier = {
+ .notifier_call = wg_netdevice_notification
+};
+
+int __init wg_device_init(void)
+{
+ int ret;
+
+#ifdef CONFIG_PM_SLEEP
+ ret = register_pm_notifier(&pm_notifier);
+ if (ret)
+ return ret;
+#endif
+
+ ret = register_netdevice_notifier(&netdevice_notifier);
+ if (ret)
+ goto error_pm;
+
+ ret = rtnl_link_register(&link_ops);
+ if (ret)
+ goto error_netdevice;
+
+ return 0;
+
+error_netdevice:
+ unregister_netdevice_notifier(&netdevice_notifier);
+error_pm:
+#ifdef CONFIG_PM_SLEEP
+ unregister_pm_notifier(&pm_notifier);
+#endif
+ return ret;
+}
+
+void wg_device_uninit(void)
+{
+ rtnl_link_unregister(&link_ops);
+ unregister_netdevice_notifier(&netdevice_notifier);
+#ifdef CONFIG_PM_SLEEP
+ unregister_pm_notifier(&pm_notifier);
+#endif
+ rcu_barrier();
+}