OpenCloudOS-Kernel/drivers/net/wireguard/socket.c

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net: WireGuard secure network tunnel 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>
2019-12-09 07:27:34 +08:00
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/
#include "device.h"
#include "peer.h"
#include "socket.h"
#include "queueing.h"
#include "messages.h"
#include <linux/ctype.h>
#include <linux/net.h>
#include <linux/if_vlan.h>
#include <linux/if_ether.h>
#include <linux/inetdevice.h>
#include <net/udp_tunnel.h>
#include <net/ipv6.h>
static int send4(struct wg_device *wg, struct sk_buff *skb,
struct endpoint *endpoint, u8 ds, struct dst_cache *cache)
{
struct flowi4 fl = {
.saddr = endpoint->src4.s_addr,
.daddr = endpoint->addr4.sin_addr.s_addr,
.fl4_dport = endpoint->addr4.sin_port,
.flowi4_mark = wg->fwmark,
.flowi4_proto = IPPROTO_UDP
};
struct rtable *rt = NULL;
struct sock *sock;
int ret = 0;
skb_mark_not_on_list(skb);
skb->dev = wg->dev;
skb->mark = wg->fwmark;
rcu_read_lock_bh();
sock = rcu_dereference_bh(wg->sock4);
if (unlikely(!sock)) {
ret = -ENONET;
goto err;
}
fl.fl4_sport = inet_sk(sock)->inet_sport;
if (cache)
rt = dst_cache_get_ip4(cache, &fl.saddr);
if (!rt) {
security_sk_classify_flow(sock, flowi4_to_flowi(&fl));
if (unlikely(!inet_confirm_addr(sock_net(sock), NULL, 0,
fl.saddr, RT_SCOPE_HOST))) {
endpoint->src4.s_addr = 0;
*(__force __be32 *)&endpoint->src_if4 = 0;
fl.saddr = 0;
if (cache)
dst_cache_reset(cache);
}
rt = ip_route_output_flow(sock_net(sock), &fl, sock);
if (unlikely(endpoint->src_if4 && ((IS_ERR(rt) &&
PTR_ERR(rt) == -EINVAL) || (!IS_ERR(rt) &&
rt->dst.dev->ifindex != endpoint->src_if4)))) {
endpoint->src4.s_addr = 0;
*(__force __be32 *)&endpoint->src_if4 = 0;
fl.saddr = 0;
if (cache)
dst_cache_reset(cache);
if (!IS_ERR(rt))
ip_rt_put(rt);
rt = ip_route_output_flow(sock_net(sock), &fl, sock);
}
if (unlikely(IS_ERR(rt))) {
ret = PTR_ERR(rt);
net_dbg_ratelimited("%s: No route to %pISpfsc, error %d\n",
wg->dev->name, &endpoint->addr, ret);
goto err;
} else if (unlikely(rt->dst.dev == skb->dev)) {
ip_rt_put(rt);
ret = -ELOOP;
net_dbg_ratelimited("%s: Avoiding routing loop to %pISpfsc\n",
wg->dev->name, &endpoint->addr);
goto err;
}
if (cache)
dst_cache_set_ip4(cache, &rt->dst, fl.saddr);
}
skb->ignore_df = 1;
udp_tunnel_xmit_skb(rt, sock, skb, fl.saddr, fl.daddr, ds,
ip4_dst_hoplimit(&rt->dst), 0, fl.fl4_sport,
fl.fl4_dport, false, false);
goto out;
err:
kfree_skb(skb);
out:
rcu_read_unlock_bh();
return ret;
}
static int send6(struct wg_device *wg, struct sk_buff *skb,
struct endpoint *endpoint, u8 ds, struct dst_cache *cache)
{
#if IS_ENABLED(CONFIG_IPV6)
struct flowi6 fl = {
.saddr = endpoint->src6,
.daddr = endpoint->addr6.sin6_addr,
.fl6_dport = endpoint->addr6.sin6_port,
.flowi6_mark = wg->fwmark,
.flowi6_oif = endpoint->addr6.sin6_scope_id,
.flowi6_proto = IPPROTO_UDP
/* TODO: addr->sin6_flowinfo */
};
struct dst_entry *dst = NULL;
struct sock *sock;
int ret = 0;
skb_mark_not_on_list(skb);
skb->dev = wg->dev;
skb->mark = wg->fwmark;
rcu_read_lock_bh();
sock = rcu_dereference_bh(wg->sock6);
if (unlikely(!sock)) {
ret = -ENONET;
goto err;
}
fl.fl6_sport = inet_sk(sock)->inet_sport;
if (cache)
dst = dst_cache_get_ip6(cache, &fl.saddr);
if (!dst) {
security_sk_classify_flow(sock, flowi6_to_flowi(&fl));
if (unlikely(!ipv6_addr_any(&fl.saddr) &&
!ipv6_chk_addr(sock_net(sock), &fl.saddr, NULL, 0))) {
endpoint->src6 = fl.saddr = in6addr_any;
if (cache)
dst_cache_reset(cache);
}
dst = ipv6_stub->ipv6_dst_lookup_flow(sock_net(sock), sock, &fl,
NULL);
if (unlikely(IS_ERR(dst))) {
ret = PTR_ERR(dst);
net_dbg_ratelimited("%s: No route to %pISpfsc, error %d\n",
wg->dev->name, &endpoint->addr, ret);
goto err;
} else if (unlikely(dst->dev == skb->dev)) {
dst_release(dst);
ret = -ELOOP;
net_dbg_ratelimited("%s: Avoiding routing loop to %pISpfsc\n",
wg->dev->name, &endpoint->addr);
goto err;
}
if (cache)
dst_cache_set_ip6(cache, dst, &fl.saddr);
}
skb->ignore_df = 1;
udp_tunnel6_xmit_skb(dst, sock, skb, skb->dev, &fl.saddr, &fl.daddr, ds,
ip6_dst_hoplimit(dst), 0, fl.fl6_sport,
fl.fl6_dport, false);
goto out;
err:
kfree_skb(skb);
out:
rcu_read_unlock_bh();
return ret;
#else
return -EAFNOSUPPORT;
#endif
}
int wg_socket_send_skb_to_peer(struct wg_peer *peer, struct sk_buff *skb, u8 ds)
{
size_t skb_len = skb->len;
int ret = -EAFNOSUPPORT;
read_lock_bh(&peer->endpoint_lock);
if (peer->endpoint.addr.sa_family == AF_INET)
ret = send4(peer->device, skb, &peer->endpoint, ds,
&peer->endpoint_cache);
else if (peer->endpoint.addr.sa_family == AF_INET6)
ret = send6(peer->device, skb, &peer->endpoint, ds,
&peer->endpoint_cache);
else
dev_kfree_skb(skb);
if (likely(!ret))
peer->tx_bytes += skb_len;
read_unlock_bh(&peer->endpoint_lock);
return ret;
}
int wg_socket_send_buffer_to_peer(struct wg_peer *peer, void *buffer,
size_t len, u8 ds)
{
struct sk_buff *skb = alloc_skb(len + SKB_HEADER_LEN, GFP_ATOMIC);
if (unlikely(!skb))
return -ENOMEM;
skb_reserve(skb, SKB_HEADER_LEN);
skb_set_inner_network_header(skb, 0);
skb_put_data(skb, buffer, len);
return wg_socket_send_skb_to_peer(peer, skb, ds);
}
int wg_socket_send_buffer_as_reply_to_skb(struct wg_device *wg,
struct sk_buff *in_skb, void *buffer,
size_t len)
{
int ret = 0;
struct sk_buff *skb;
struct endpoint endpoint;
if (unlikely(!in_skb))
return -EINVAL;
ret = wg_socket_endpoint_from_skb(&endpoint, in_skb);
if (unlikely(ret < 0))
return ret;
skb = alloc_skb(len + SKB_HEADER_LEN, GFP_ATOMIC);
if (unlikely(!skb))
return -ENOMEM;
skb_reserve(skb, SKB_HEADER_LEN);
skb_set_inner_network_header(skb, 0);
skb_put_data(skb, buffer, len);
if (endpoint.addr.sa_family == AF_INET)
ret = send4(wg, skb, &endpoint, 0, NULL);
else if (endpoint.addr.sa_family == AF_INET6)
ret = send6(wg, skb, &endpoint, 0, NULL);
/* No other possibilities if the endpoint is valid, which it is,
* as we checked above.
*/
return ret;
}
int wg_socket_endpoint_from_skb(struct endpoint *endpoint,
const struct sk_buff *skb)
{
memset(endpoint, 0, sizeof(*endpoint));
if (skb->protocol == htons(ETH_P_IP)) {
endpoint->addr4.sin_family = AF_INET;
endpoint->addr4.sin_port = udp_hdr(skb)->source;
endpoint->addr4.sin_addr.s_addr = ip_hdr(skb)->saddr;
endpoint->src4.s_addr = ip_hdr(skb)->daddr;
endpoint->src_if4 = skb->skb_iif;
} else if (skb->protocol == htons(ETH_P_IPV6)) {
endpoint->addr6.sin6_family = AF_INET6;
endpoint->addr6.sin6_port = udp_hdr(skb)->source;
endpoint->addr6.sin6_addr = ipv6_hdr(skb)->saddr;
endpoint->addr6.sin6_scope_id = ipv6_iface_scope_id(
&ipv6_hdr(skb)->saddr, skb->skb_iif);
endpoint->src6 = ipv6_hdr(skb)->daddr;
} else {
return -EINVAL;
}
return 0;
}
static bool endpoint_eq(const struct endpoint *a, const struct endpoint *b)
{
return (a->addr.sa_family == AF_INET && b->addr.sa_family == AF_INET &&
a->addr4.sin_port == b->addr4.sin_port &&
a->addr4.sin_addr.s_addr == b->addr4.sin_addr.s_addr &&
a->src4.s_addr == b->src4.s_addr && a->src_if4 == b->src_if4) ||
(a->addr.sa_family == AF_INET6 &&
b->addr.sa_family == AF_INET6 &&
a->addr6.sin6_port == b->addr6.sin6_port &&
ipv6_addr_equal(&a->addr6.sin6_addr, &b->addr6.sin6_addr) &&
a->addr6.sin6_scope_id == b->addr6.sin6_scope_id &&
ipv6_addr_equal(&a->src6, &b->src6)) ||
unlikely(!a->addr.sa_family && !b->addr.sa_family);
}
void wg_socket_set_peer_endpoint(struct wg_peer *peer,
const struct endpoint *endpoint)
{
/* First we check unlocked, in order to optimize, since it's pretty rare
* that an endpoint will change. If we happen to be mid-write, and two
* CPUs wind up writing the same thing or something slightly different,
* it doesn't really matter much either.
*/
if (endpoint_eq(endpoint, &peer->endpoint))
return;
write_lock_bh(&peer->endpoint_lock);
if (endpoint->addr.sa_family == AF_INET) {
peer->endpoint.addr4 = endpoint->addr4;
peer->endpoint.src4 = endpoint->src4;
peer->endpoint.src_if4 = endpoint->src_if4;
} else if (endpoint->addr.sa_family == AF_INET6) {
peer->endpoint.addr6 = endpoint->addr6;
peer->endpoint.src6 = endpoint->src6;
} else {
goto out;
}
dst_cache_reset(&peer->endpoint_cache);
out:
write_unlock_bh(&peer->endpoint_lock);
}
void wg_socket_set_peer_endpoint_from_skb(struct wg_peer *peer,
const struct sk_buff *skb)
{
struct endpoint endpoint;
if (!wg_socket_endpoint_from_skb(&endpoint, skb))
wg_socket_set_peer_endpoint(peer, &endpoint);
}
void wg_socket_clear_peer_endpoint_src(struct wg_peer *peer)
{
write_lock_bh(&peer->endpoint_lock);
memset(&peer->endpoint.src6, 0, sizeof(peer->endpoint.src6));
dst_cache_reset(&peer->endpoint_cache);
write_unlock_bh(&peer->endpoint_lock);
}
static int wg_receive(struct sock *sk, struct sk_buff *skb)
{
struct wg_device *wg;
if (unlikely(!sk))
goto err;
wg = sk->sk_user_data;
if (unlikely(!wg))
goto err;
skb_mark_not_on_list(skb);
net: WireGuard secure network tunnel 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>
2019-12-09 07:27:34 +08:00
wg_packet_receive(wg, skb);
return 0;
err:
kfree_skb(skb);
return 0;
}
static void sock_free(struct sock *sock)
{
if (unlikely(!sock))
return;
sk_clear_memalloc(sock);
udp_tunnel_sock_release(sock->sk_socket);
}
static void set_sock_opts(struct socket *sock)
{
sock->sk->sk_allocation = GFP_ATOMIC;
sock->sk->sk_sndbuf = INT_MAX;
sk_set_memalloc(sock->sk);
}
int wg_socket_init(struct wg_device *wg, u16 port)
{
int ret;
struct udp_tunnel_sock_cfg cfg = {
.sk_user_data = wg,
.encap_type = 1,
.encap_rcv = wg_receive
};
struct socket *new4 = NULL, *new6 = NULL;
struct udp_port_cfg port4 = {
.family = AF_INET,
.local_ip.s_addr = htonl(INADDR_ANY),
.local_udp_port = htons(port),
.use_udp_checksums = true
};
#if IS_ENABLED(CONFIG_IPV6)
int retries = 0;
struct udp_port_cfg port6 = {
.family = AF_INET6,
.local_ip6 = IN6ADDR_ANY_INIT,
.use_udp6_tx_checksums = true,
.use_udp6_rx_checksums = true,
.ipv6_v6only = true
};
#endif
#if IS_ENABLED(CONFIG_IPV6)
retry:
#endif
ret = udp_sock_create(wg->creating_net, &port4, &new4);
if (ret < 0) {
pr_err("%s: Could not create IPv4 socket\n", wg->dev->name);
return ret;
}
set_sock_opts(new4);
setup_udp_tunnel_sock(wg->creating_net, new4, &cfg);
#if IS_ENABLED(CONFIG_IPV6)
if (ipv6_mod_enabled()) {
port6.local_udp_port = inet_sk(new4->sk)->inet_sport;
ret = udp_sock_create(wg->creating_net, &port6, &new6);
if (ret < 0) {
udp_tunnel_sock_release(new4);
if (ret == -EADDRINUSE && !port && retries++ < 100)
goto retry;
pr_err("%s: Could not create IPv6 socket\n",
wg->dev->name);
return ret;
}
set_sock_opts(new6);
setup_udp_tunnel_sock(wg->creating_net, new6, &cfg);
}
#endif
wg_socket_reinit(wg, new4->sk, new6 ? new6->sk : NULL);
return 0;
}
void wg_socket_reinit(struct wg_device *wg, struct sock *new4,
struct sock *new6)
{
struct sock *old4, *old6;
mutex_lock(&wg->socket_update_lock);
old4 = rcu_dereference_protected(wg->sock4,
lockdep_is_held(&wg->socket_update_lock));
old6 = rcu_dereference_protected(wg->sock6,
lockdep_is_held(&wg->socket_update_lock));
rcu_assign_pointer(wg->sock4, new4);
rcu_assign_pointer(wg->sock6, new6);
if (new4)
wg->incoming_port = ntohs(inet_sk(new4)->inet_sport);
mutex_unlock(&wg->socket_update_lock);
synchronize_rcu();
synchronize_net();
sock_free(old4);
sock_free(old6);
}