1#include <linux/module.h>
2#include <linux/errno.h>
3#include <linux/socket.h>
4#include <linux/udp.h>
5#include <linux/types.h>
6#include <linux/kernel.h>
7#include <net/udp.h>
8#include <net/udp_tunnel.h>
9#include <net/net_namespace.h>
10
11int udp_sock_create4(struct net *net, struct udp_port_cfg *cfg,
12		     struct socket **sockp)
13{
14	int err;
15	struct socket *sock = NULL;
16	struct sockaddr_in udp_addr;
17
18	err = sock_create_kern(AF_INET, SOCK_DGRAM, 0, &sock);
19	if (err < 0)
20		goto error;
21
22	sk_change_net(sock->sk, net);
23
24	udp_addr.sin_family = AF_INET;
25	udp_addr.sin_addr = cfg->local_ip;
26	udp_addr.sin_port = cfg->local_udp_port;
27	err = kernel_bind(sock, (struct sockaddr *)&udp_addr,
28			  sizeof(udp_addr));
29	if (err < 0)
30		goto error;
31
32	if (cfg->peer_udp_port) {
33		udp_addr.sin_family = AF_INET;
34		udp_addr.sin_addr = cfg->peer_ip;
35		udp_addr.sin_port = cfg->peer_udp_port;
36		err = kernel_connect(sock, (struct sockaddr *)&udp_addr,
37				     sizeof(udp_addr), 0);
38		if (err < 0)
39			goto error;
40	}
41
42	sock->sk->sk_no_check_tx = !cfg->use_udp_checksums;
43
44	*sockp = sock;
45	return 0;
46
47error:
48	if (sock) {
49		kernel_sock_shutdown(sock, SHUT_RDWR);
50		sk_release_kernel(sock->sk);
51	}
52	*sockp = NULL;
53	return err;
54}
55EXPORT_SYMBOL(udp_sock_create4);
56
57void setup_udp_tunnel_sock(struct net *net, struct socket *sock,
58			   struct udp_tunnel_sock_cfg *cfg)
59{
60	struct sock *sk = sock->sk;
61
62	/* Disable multicast loopback */
63	inet_sk(sk)->mc_loop = 0;
64
65	/* Enable CHECKSUM_UNNECESSARY to CHECKSUM_COMPLETE conversion */
66	inet_inc_convert_csum(sk);
67
68	rcu_assign_sk_user_data(sk, cfg->sk_user_data);
69
70	udp_sk(sk)->encap_type = cfg->encap_type;
71	udp_sk(sk)->encap_rcv = cfg->encap_rcv;
72	udp_sk(sk)->encap_destroy = cfg->encap_destroy;
73
74	udp_tunnel_encap_enable(sock);
75}
76EXPORT_SYMBOL_GPL(setup_udp_tunnel_sock);
77
78int udp_tunnel_xmit_skb(struct rtable *rt, struct sock *sk, struct sk_buff *skb,
79			__be32 src, __be32 dst, __u8 tos, __u8 ttl,
80			__be16 df, __be16 src_port, __be16 dst_port,
81			bool xnet, bool nocheck)
82{
83	struct udphdr *uh;
84
85	__skb_push(skb, sizeof(*uh));
86	skb_reset_transport_header(skb);
87	uh = udp_hdr(skb);
88
89	uh->dest = dst_port;
90	uh->source = src_port;
91	uh->len = htons(skb->len);
92
93	udp_set_csum(nocheck, skb, src, dst, skb->len);
94
95	return iptunnel_xmit(sk, rt, skb, src, dst, IPPROTO_UDP,
96			     tos, ttl, df, xnet);
97}
98EXPORT_SYMBOL_GPL(udp_tunnel_xmit_skb);
99
100void udp_tunnel_sock_release(struct socket *sock)
101{
102	rcu_assign_sk_user_data(sock->sk, NULL);
103	kernel_sock_shutdown(sock, SHUT_RDWR);
104	sk_release_kernel(sock->sk);
105}
106EXPORT_SYMBOL_GPL(udp_tunnel_sock_release);
107
108MODULE_LICENSE("GPL");
109