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/* Copyright (C) 2015-2017 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 open(struct net_device *dev)
{
int ret;
struct wireguard_peer *peer, *temp;
struct wireguard_device *wg = netdev_priv(dev);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 17, 0)
struct inet6_dev *dev_v6 = __in6_dev_get(dev);
#endif
struct in_device *dev_v4 = __in_dev_get_rtnl(dev);
if (dev_v4) {
/* TODO: when we merge to mainline, 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, rather than turning it off like this. This is just a stop gap solution
* while we're an out of tree module. */
IN_DEV_CONF_SET(dev_v4, SEND_REDIRECTS, false);
IPV4_DEVCONF_ALL(dev_net(dev), SEND_REDIRECTS) = false;
}
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 17, 0)
if (dev_v6)
#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 11, 0)
dev_v6->addr_gen_mode = IN6_ADDR_GEN_MODE_NONE;
#else
dev_v6->cnf.addr_gen_mode = IN6_ADDR_GEN_MODE_NONE;
#endif
#endif
ret = socket_init(wg);
if (ret < 0)
return ret;
peer_for_each (wg, peer, temp, true) {
packet_send_staged_packets(peer);
if (peer->persistent_keepalive_interval)
packet_send_keepalive(peer);
}
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int suspending_clear_noise_peers(struct notifier_block *nb, unsigned long action, void *data)
{
struct wireguard_device *wg;
struct wireguard_peer *peer, *temp;
if (action != PM_HIBERNATION_PREPARE && action != PM_SUSPEND_PREPARE)
return 0;
rtnl_lock();
list_for_each_entry (wg, &device_list, device_list) {
peer_for_each (wg, peer, temp, true) {
noise_handshake_clear(&peer->handshake);
noise_keypairs_clear(&peer->keypairs);
if (peer->timers_enabled)
del_timer(&peer->timer_zero_key_material);
}
}
rtnl_unlock();
rcu_barrier_bh();
return 0;
}
static struct notifier_block clear_peers_on_suspend = { .notifier_call = suspending_clear_noise_peers };
#endif
static int stop(struct net_device *dev)
{
struct wireguard_device *wg = netdev_priv(dev);
struct wireguard_peer *peer, *temp;
peer_for_each (wg, peer, temp, true) {
skb_queue_purge(&peer->staged_packet_queue);
timers_stop(peer);
noise_handshake_clear(&peer->handshake);
noise_keypairs_clear(&peer->keypairs);
}
skb_queue_purge(&wg->incoming_handshakes);
socket_uninit(wg);
return 0;
}
static netdev_tx_t xmit(struct sk_buff *skb, struct net_device *dev)
{
struct wireguard_device *wg = netdev_priv(dev);
struct wireguard_peer *peer;
struct sk_buff *next;
struct sk_buff_head packets;
int ret;
if (unlikely(dev_recursion_level() > 4)) {
ret = -ELOOP;
net_dbg_ratelimited("%s: Routing loop detected\n", dev->name);
goto err;
}
if (unlikely(skb_examine_untrusted_ip_hdr(skb) != skb->protocol)) {
ret = -EPROTONOSUPPORT;
net_dbg_ratelimited("%s: Invalid IP packet\n", dev->name);
goto err;
}
peer = routing_table_lookup_dst(&wg->peer_routing_table, skb);
if (unlikely(!peer)) {
ret = -ENOKEY;
net_dbg_skb_ratelimited("%s: No peer is configured for %pISc\n", dev->name, skb);
goto err;
}
read_lock_bh(&peer->endpoint_lock);
ret = peer->endpoint.addr.sa_family != AF_INET && peer->endpoint.addr.sa_family != AF_INET6;
read_unlock_bh(&peer->endpoint_lock);
if (unlikely(ret)) {
ret = -EDESTADDRREQ;
net_dbg_ratelimited("%s: No valid endpoint has been configured or discovered for peer %Lu\n", dev->name, peer->internal_id);
goto err_peer;
}
__skb_queue_head_init(&packets);
if (!skb_is_gso(skb))
skb->next = NULL;
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->next = skb->prev = NULL;
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);
__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));
skb_queue_splice_tail(&packets, &peer->staged_packet_queue);
spin_unlock_bh(&peer->staged_packet_queue.lock);
packet_send_staged_packets(peer);
peer_put(peer);
return NETDEV_TX_OK;
err_peer:
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 = open,
.ndo_stop = stop,
.ndo_start_xmit = xmit,
.ndo_get_stats64 = ip_tunnel_get_stats64
};
static void destruct(struct net_device *dev)
{
struct wireguard_device *wg = netdev_priv(dev);
rtnl_lock();
list_del(&wg->device_list);
rtnl_unlock();
mutex_lock(&wg->device_update_lock);
peer_remove_all(wg); /* The final references are cleared in the below calls to destroy_workqueue. */
wg->incoming_port = 0;
destroy_workqueue(wg->handshake_receive_wq);
destroy_workqueue(wg->handshake_send_wq);
packet_queue_free(&wg->decrypt_queue, true);
packet_queue_free(&wg->encrypt_queue, true);
destroy_workqueue(wg->packet_crypt_wq);
routing_table_free(&wg->peer_routing_table);
ratelimiter_uninit();
memzero_explicit(&wg->static_identity, sizeof(struct noise_static_identity));
skb_queue_purge(&wg->incoming_handshakes);
socket_uninit(wg);
mutex_unlock(&wg->device_update_lock);
free_percpu(dev->tstats);
free_percpu(wg->incoming_handshakes_worker);
put_net(wg->creating_net);
pr_debug("%s: Interface deleted\n", dev->name);
free_netdev(dev);
}
static void setup(struct net_device *dev)
{
struct wireguard_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;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 3, 0)
dev->priv_flags |= IFF_NO_QUEUE;
#else
dev->tx_queue_len = 0;
#endif
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));
/* We need to keep the dst around in case of icmp replies. */
netif_keep_dst(dev);
memset(wg, 0, sizeof(struct wireguard_device));
wg->dev = dev;
}
static int newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[], struct nlattr *data[], struct netlink_ext_ack *extack)
{
int ret = -ENOMEM;
struct wireguard_device *wg = netdev_priv(dev);
wg->creating_net = get_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);
pubkey_hashtable_init(&wg->peer_hashtable);
index_hashtable_init(&wg->index_hashtable);
routing_table_init(&wg->peer_routing_table);
cookie_checker_init(&wg->cookie_checker, wg);
INIT_LIST_HEAD(&wg->peer_list);
wg->device_update_gen = 1;
dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
if (!dev->tstats)
goto error_1;
wg->incoming_handshakes_worker = packet_alloc_percpu_multicore_worker(packet_handshake_receive_worker, wg);
if (!wg->incoming_handshakes_worker)
goto error_2;
wg->handshake_receive_wq = alloc_workqueue("wg-kex-%s", WQ_CPU_INTENSIVE | WQ_FREEZABLE, 0, dev->name);
if (!wg->handshake_receive_wq)
goto error_3;
wg->handshake_send_wq = alloc_workqueue("wg-kex-%s", WQ_UNBOUND | WQ_FREEZABLE, 0, dev->name);
if (!wg->handshake_send_wq)
goto error_4;
wg->packet_crypt_wq = alloc_workqueue("wg-crypt-%s", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 0, dev->name);
if (!wg->packet_crypt_wq)
goto error_5;
if (packet_queue_init(&wg->encrypt_queue, packet_encrypt_worker, true, MAX_QUEUED_PACKETS) < 0)
goto error_6;
if (packet_queue_init(&wg->decrypt_queue, packet_decrypt_worker, true, MAX_QUEUED_PACKETS) < 0)
goto error_7;
ret = ratelimiter_init();
if (ret < 0)
goto error_8;
ret = register_netdevice(dev);
if (ret < 0)
goto error_9;
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 = destruct;
pr_debug("%s: Interface created\n", dev->name);
return ret;
error_9:
ratelimiter_uninit();
error_8:
packet_queue_free(&wg->decrypt_queue, true);
error_7:
packet_queue_free(&wg->encrypt_queue, true);
error_6:
destroy_workqueue(wg->packet_crypt_wq);
error_5:
destroy_workqueue(wg->handshake_send_wq);
error_4:
destroy_workqueue(wg->handshake_receive_wq);
error_3:
free_percpu(wg->incoming_handshakes_worker);
error_2:
free_percpu(dev->tstats);
error_1:
put_net(src_net);
return ret;
}
static struct rtnl_link_ops link_ops __read_mostly = {
.kind = KBUILD_MODNAME,
.priv_size = sizeof(struct wireguard_device),
.setup = setup,
.newlink = newlink,
};
int __init device_init(void)
{
#ifdef CONFIG_PM_SLEEP
int ret = register_pm_notifier(&clear_peers_on_suspend);
if (ret)
return ret;
#endif
return rtnl_link_register(&link_ops);
}
void device_uninit(void)
{
rtnl_link_unregister(&link_ops);
#ifdef CONFIG_PM_SLEEP
unregister_pm_notifier(&clear_peers_on_suspend);
#endif
rcu_barrier_bh();
}
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