xref: /openbmc/linux/net/ipv4/udp_tunnel_core.c (revision 52cdded0)
1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/module.h>
3 #include <linux/errno.h>
4 #include <linux/socket.h>
5 #include <linux/udp.h>
6 #include <linux/types.h>
7 #include <linux/kernel.h>
8 #include <net/dst_metadata.h>
9 #include <net/net_namespace.h>
10 #include <net/udp.h>
11 #include <net/udp_tunnel.h>
12 
13 int udp_sock_create4(struct net *net, struct udp_port_cfg *cfg,
14 		     struct socket **sockp)
15 {
16 	int err;
17 	struct socket *sock = NULL;
18 	struct sockaddr_in udp_addr;
19 
20 	err = sock_create_kern(net, AF_INET, SOCK_DGRAM, 0, &sock);
21 	if (err < 0)
22 		goto error;
23 
24 	if (cfg->bind_ifindex) {
25 		err = sock_bindtoindex(sock->sk, cfg->bind_ifindex, true);
26 		if (err < 0)
27 			goto error;
28 	}
29 
30 	udp_addr.sin_family = AF_INET;
31 	udp_addr.sin_addr = cfg->local_ip;
32 	udp_addr.sin_port = cfg->local_udp_port;
33 	err = kernel_bind(sock, (struct sockaddr *)&udp_addr,
34 			  sizeof(udp_addr));
35 	if (err < 0)
36 		goto error;
37 
38 	if (cfg->peer_udp_port) {
39 		udp_addr.sin_family = AF_INET;
40 		udp_addr.sin_addr = cfg->peer_ip;
41 		udp_addr.sin_port = cfg->peer_udp_port;
42 		err = kernel_connect(sock, (struct sockaddr *)&udp_addr,
43 				     sizeof(udp_addr), 0);
44 		if (err < 0)
45 			goto error;
46 	}
47 
48 	sock->sk->sk_no_check_tx = !cfg->use_udp_checksums;
49 
50 	*sockp = sock;
51 	return 0;
52 
53 error:
54 	if (sock) {
55 		kernel_sock_shutdown(sock, SHUT_RDWR);
56 		sock_release(sock);
57 	}
58 	*sockp = NULL;
59 	return err;
60 }
61 EXPORT_SYMBOL(udp_sock_create4);
62 
63 void setup_udp_tunnel_sock(struct net *net, struct socket *sock,
64 			   struct udp_tunnel_sock_cfg *cfg)
65 {
66 	struct sock *sk = sock->sk;
67 
68 	/* Disable multicast loopback */
69 	inet_sk(sk)->mc_loop = 0;
70 
71 	/* Enable CHECKSUM_UNNECESSARY to CHECKSUM_COMPLETE conversion */
72 	inet_inc_convert_csum(sk);
73 
74 	rcu_assign_sk_user_data(sk, cfg->sk_user_data);
75 
76 	udp_sk(sk)->encap_type = cfg->encap_type;
77 	udp_sk(sk)->encap_rcv = cfg->encap_rcv;
78 	udp_sk(sk)->encap_err_lookup = cfg->encap_err_lookup;
79 	udp_sk(sk)->encap_destroy = cfg->encap_destroy;
80 	udp_sk(sk)->gro_receive = cfg->gro_receive;
81 	udp_sk(sk)->gro_complete = cfg->gro_complete;
82 
83 	udp_tunnel_encap_enable(sock);
84 }
85 EXPORT_SYMBOL_GPL(setup_udp_tunnel_sock);
86 
87 void udp_tunnel_push_rx_port(struct net_device *dev, struct socket *sock,
88 			     unsigned short type)
89 {
90 	struct sock *sk = sock->sk;
91 	struct udp_tunnel_info ti;
92 
93 	if (!dev->netdev_ops->ndo_udp_tunnel_add ||
94 	    !(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
95 		return;
96 
97 	ti.type = type;
98 	ti.sa_family = sk->sk_family;
99 	ti.port = inet_sk(sk)->inet_sport;
100 
101 	dev->netdev_ops->ndo_udp_tunnel_add(dev, &ti);
102 }
103 EXPORT_SYMBOL_GPL(udp_tunnel_push_rx_port);
104 
105 void udp_tunnel_drop_rx_port(struct net_device *dev, struct socket *sock,
106 			     unsigned short type)
107 {
108 	struct sock *sk = sock->sk;
109 	struct udp_tunnel_info ti;
110 
111 	if (!dev->netdev_ops->ndo_udp_tunnel_del ||
112 	    !(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
113 		return;
114 
115 	ti.type = type;
116 	ti.sa_family = sk->sk_family;
117 	ti.port = inet_sk(sk)->inet_sport;
118 
119 	dev->netdev_ops->ndo_udp_tunnel_del(dev, &ti);
120 }
121 EXPORT_SYMBOL_GPL(udp_tunnel_drop_rx_port);
122 
123 /* Notify netdevs that UDP port started listening */
124 void udp_tunnel_notify_add_rx_port(struct socket *sock, unsigned short type)
125 {
126 	struct sock *sk = sock->sk;
127 	struct net *net = sock_net(sk);
128 	struct udp_tunnel_info ti;
129 	struct net_device *dev;
130 
131 	ti.type = type;
132 	ti.sa_family = sk->sk_family;
133 	ti.port = inet_sk(sk)->inet_sport;
134 
135 	rcu_read_lock();
136 	for_each_netdev_rcu(net, dev) {
137 		if (!dev->netdev_ops->ndo_udp_tunnel_add)
138 			continue;
139 		if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
140 			continue;
141 		dev->netdev_ops->ndo_udp_tunnel_add(dev, &ti);
142 	}
143 	rcu_read_unlock();
144 }
145 EXPORT_SYMBOL_GPL(udp_tunnel_notify_add_rx_port);
146 
147 /* Notify netdevs that UDP port is no more listening */
148 void udp_tunnel_notify_del_rx_port(struct socket *sock, unsigned short type)
149 {
150 	struct sock *sk = sock->sk;
151 	struct net *net = sock_net(sk);
152 	struct udp_tunnel_info ti;
153 	struct net_device *dev;
154 
155 	ti.type = type;
156 	ti.sa_family = sk->sk_family;
157 	ti.port = inet_sk(sk)->inet_sport;
158 
159 	rcu_read_lock();
160 	for_each_netdev_rcu(net, dev) {
161 		if (!dev->netdev_ops->ndo_udp_tunnel_del)
162 			continue;
163 		if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
164 			continue;
165 		dev->netdev_ops->ndo_udp_tunnel_del(dev, &ti);
166 	}
167 	rcu_read_unlock();
168 }
169 EXPORT_SYMBOL_GPL(udp_tunnel_notify_del_rx_port);
170 
171 void udp_tunnel_xmit_skb(struct rtable *rt, struct sock *sk, struct sk_buff *skb,
172 			 __be32 src, __be32 dst, __u8 tos, __u8 ttl,
173 			 __be16 df, __be16 src_port, __be16 dst_port,
174 			 bool xnet, bool nocheck)
175 {
176 	struct udphdr *uh;
177 
178 	__skb_push(skb, sizeof(*uh));
179 	skb_reset_transport_header(skb);
180 	uh = udp_hdr(skb);
181 
182 	uh->dest = dst_port;
183 	uh->source = src_port;
184 	uh->len = htons(skb->len);
185 
186 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
187 
188 	udp_set_csum(nocheck, skb, src, dst, skb->len);
189 
190 	iptunnel_xmit(sk, rt, skb, src, dst, IPPROTO_UDP, tos, ttl, df, xnet);
191 }
192 EXPORT_SYMBOL_GPL(udp_tunnel_xmit_skb);
193 
194 void udp_tunnel_sock_release(struct socket *sock)
195 {
196 	rcu_assign_sk_user_data(sock->sk, NULL);
197 	kernel_sock_shutdown(sock, SHUT_RDWR);
198 	sock_release(sock);
199 }
200 EXPORT_SYMBOL_GPL(udp_tunnel_sock_release);
201 
202 struct metadata_dst *udp_tun_rx_dst(struct sk_buff *skb,  unsigned short family,
203 				    __be16 flags, __be64 tunnel_id, int md_size)
204 {
205 	struct metadata_dst *tun_dst;
206 	struct ip_tunnel_info *info;
207 
208 	if (family == AF_INET)
209 		tun_dst = ip_tun_rx_dst(skb, flags, tunnel_id, md_size);
210 	else
211 		tun_dst = ipv6_tun_rx_dst(skb, flags, tunnel_id, md_size);
212 	if (!tun_dst)
213 		return NULL;
214 
215 	info = &tun_dst->u.tun_info;
216 	info->key.tp_src = udp_hdr(skb)->source;
217 	info->key.tp_dst = udp_hdr(skb)->dest;
218 	if (udp_hdr(skb)->check)
219 		info->key.tun_flags |= TUNNEL_CSUM;
220 	return tun_dst;
221 }
222 EXPORT_SYMBOL_GPL(udp_tun_rx_dst);
223 
224 MODULE_LICENSE("GPL");
225