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path: root/drivers/net/wireguard/socket.c
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Diffstat (limited to 'drivers/net/wireguard/socket.c')
-rw-r--r--drivers/net/wireguard/socket.c433
1 files changed, 433 insertions, 0 deletions
diff --git a/drivers/net/wireguard/socket.c b/drivers/net/wireguard/socket.c
new file mode 100644
index 000000000000..5a77b0c9ba2e
--- /dev/null
+++ b/drivers/net/wireguard/socket.c
@@ -0,0 +1,433 @@
+// 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->next = skb->prev = NULL;
+ 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);
+ }
+ 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->next = skb->prev = NULL;
+ 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);
+ }
+ ret = ipv6_stub->ipv6_dst_lookup(sock_net(sock), sock, &dst,
+ &fl);
+ if (unlikely(ret)) {
+ 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);
+ }
+
+ 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;
+ 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 ? new4->sk : NULL, 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);
+}