xref: /openbmc/linux/net/ipv4/udp_tunnel_core.c (revision b737eecd)
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 	ti.type = type;
94 	ti.sa_family = sk->sk_family;
95 	ti.port = inet_sk(sk)->inet_sport;
96 
97 	udp_tunnel_nic_add_port(dev, &ti);
98 }
99 EXPORT_SYMBOL_GPL(udp_tunnel_push_rx_port);
100 
101 void udp_tunnel_drop_rx_port(struct net_device *dev, struct socket *sock,
102 			     unsigned short type)
103 {
104 	struct sock *sk = sock->sk;
105 	struct udp_tunnel_info ti;
106 
107 	ti.type = type;
108 	ti.sa_family = sk->sk_family;
109 	ti.port = inet_sk(sk)->inet_sport;
110 
111 	udp_tunnel_nic_del_port(dev, &ti);
112 }
113 EXPORT_SYMBOL_GPL(udp_tunnel_drop_rx_port);
114 
115 /* Notify netdevs that UDP port started listening */
116 void udp_tunnel_notify_add_rx_port(struct socket *sock, unsigned short type)
117 {
118 	struct sock *sk = sock->sk;
119 	struct net *net = sock_net(sk);
120 	struct udp_tunnel_info ti;
121 	struct net_device *dev;
122 
123 	ti.type = type;
124 	ti.sa_family = sk->sk_family;
125 	ti.port = inet_sk(sk)->inet_sport;
126 
127 	rcu_read_lock();
128 	for_each_netdev_rcu(net, dev) {
129 		udp_tunnel_nic_add_port(dev, &ti);
130 	}
131 	rcu_read_unlock();
132 }
133 EXPORT_SYMBOL_GPL(udp_tunnel_notify_add_rx_port);
134 
135 /* Notify netdevs that UDP port is no more listening */
136 void udp_tunnel_notify_del_rx_port(struct socket *sock, unsigned short type)
137 {
138 	struct sock *sk = sock->sk;
139 	struct net *net = sock_net(sk);
140 	struct udp_tunnel_info ti;
141 	struct net_device *dev;
142 
143 	ti.type = type;
144 	ti.sa_family = sk->sk_family;
145 	ti.port = inet_sk(sk)->inet_sport;
146 
147 	rcu_read_lock();
148 	for_each_netdev_rcu(net, dev) {
149 		udp_tunnel_nic_del_port(dev, &ti);
150 	}
151 	rcu_read_unlock();
152 }
153 EXPORT_SYMBOL_GPL(udp_tunnel_notify_del_rx_port);
154 
155 void udp_tunnel_xmit_skb(struct rtable *rt, struct sock *sk, struct sk_buff *skb,
156 			 __be32 src, __be32 dst, __u8 tos, __u8 ttl,
157 			 __be16 df, __be16 src_port, __be16 dst_port,
158 			 bool xnet, bool nocheck)
159 {
160 	struct udphdr *uh;
161 
162 	__skb_push(skb, sizeof(*uh));
163 	skb_reset_transport_header(skb);
164 	uh = udp_hdr(skb);
165 
166 	uh->dest = dst_port;
167 	uh->source = src_port;
168 	uh->len = htons(skb->len);
169 
170 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
171 
172 	udp_set_csum(nocheck, skb, src, dst, skb->len);
173 
174 	iptunnel_xmit(sk, rt, skb, src, dst, IPPROTO_UDP, tos, ttl, df, xnet);
175 }
176 EXPORT_SYMBOL_GPL(udp_tunnel_xmit_skb);
177 
178 void udp_tunnel_sock_release(struct socket *sock)
179 {
180 	rcu_assign_sk_user_data(sock->sk, NULL);
181 	kernel_sock_shutdown(sock, SHUT_RDWR);
182 	sock_release(sock);
183 }
184 EXPORT_SYMBOL_GPL(udp_tunnel_sock_release);
185 
186 struct metadata_dst *udp_tun_rx_dst(struct sk_buff *skb,  unsigned short family,
187 				    __be16 flags, __be64 tunnel_id, int md_size)
188 {
189 	struct metadata_dst *tun_dst;
190 	struct ip_tunnel_info *info;
191 
192 	if (family == AF_INET)
193 		tun_dst = ip_tun_rx_dst(skb, flags, tunnel_id, md_size);
194 	else
195 		tun_dst = ipv6_tun_rx_dst(skb, flags, tunnel_id, md_size);
196 	if (!tun_dst)
197 		return NULL;
198 
199 	info = &tun_dst->u.tun_info;
200 	info->key.tp_src = udp_hdr(skb)->source;
201 	info->key.tp_dst = udp_hdr(skb)->dest;
202 	if (udp_hdr(skb)->check)
203 		info->key.tun_flags |= TUNNEL_CSUM;
204 	return tun_dst;
205 }
206 EXPORT_SYMBOL_GPL(udp_tun_rx_dst);
207 
208 MODULE_LICENSE("GPL");
209