1
2// SPDX-License-Identifier: GPL-2.0-only
3#include <linux/module.h>
4#include <linux/errno.h>
5#include <linux/socket.h>
6#include <linux/udp.h>
7#include <linux/types.h>
8#include <linux/kernel.h>
9#include <linux/in6.h>
10#include <net/udp.h>
11#include <net/udp_tunnel.h>
12#include <net/net_namespace.h>
13#include <net/netns/generic.h>
14#include <net/ip6_tunnel.h>
15#include <net/ip6_checksum.h>
16
17int udp_sock_create6(struct net *net, struct udp_port_cfg *cfg,
18		     struct socket **sockp)
19{
20	struct sockaddr_in6 udp6_addr = {};
21	int err;
22	struct socket *sock = NULL;
23
24	err = sock_create_kern(net, AF_INET6, SOCK_DGRAM, 0, &sock);
25	if (err < 0)
26		goto error;
27
28	if (cfg->ipv6_v6only) {
29		err = ip6_sock_set_v6only(sock->sk);
30		if (err < 0)
31			goto error;
32	}
33	if (cfg->bind_ifindex) {
34		err = sock_bindtoindex(sock->sk, cfg->bind_ifindex, true);
35		if (err < 0)
36			goto error;
37	}
38
39	udp6_addr.sin6_family = AF_INET6;
40	memcpy(&udp6_addr.sin6_addr, &cfg->local_ip6,
41	       sizeof(udp6_addr.sin6_addr));
42	udp6_addr.sin6_port = cfg->local_udp_port;
43	err = kernel_bind(sock, (struct sockaddr *)&udp6_addr,
44			  sizeof(udp6_addr));
45	if (err < 0)
46		goto error;
47
48	if (cfg->peer_udp_port) {
49		memset(&udp6_addr, 0, sizeof(udp6_addr));
50		udp6_addr.sin6_family = AF_INET6;
51		memcpy(&udp6_addr.sin6_addr, &cfg->peer_ip6,
52		       sizeof(udp6_addr.sin6_addr));
53		udp6_addr.sin6_port = cfg->peer_udp_port;
54		err = kernel_connect(sock,
55				     (struct sockaddr *)&udp6_addr,
56				     sizeof(udp6_addr), 0);
57	}
58	if (err < 0)
59		goto error;
60
61	udp_set_no_check6_tx(sock->sk, !cfg->use_udp6_tx_checksums);
62	udp_set_no_check6_rx(sock->sk, !cfg->use_udp6_rx_checksums);
63
64	*sockp = sock;
65	return 0;
66
67error:
68	if (sock) {
69		kernel_sock_shutdown(sock, SHUT_RDWR);
70		sock_release(sock);
71	}
72	*sockp = NULL;
73	return err;
74}
75EXPORT_SYMBOL_GPL(udp_sock_create6);
76
77int udp_tunnel6_xmit_skb(struct dst_entry *dst, struct sock *sk,
78			 struct sk_buff *skb,
79			 struct net_device *dev,
80			 const struct in6_addr *saddr,
81			 const struct in6_addr *daddr,
82			 __u8 prio, __u8 ttl, __be32 label,
83			 __be16 src_port, __be16 dst_port, bool nocheck)
84{
85	struct udphdr *uh;
86	struct ipv6hdr *ip6h;
87
88	__skb_push(skb, sizeof(*uh));
89	skb_reset_transport_header(skb);
90	uh = udp_hdr(skb);
91
92	uh->dest = dst_port;
93	uh->source = src_port;
94
95	uh->len = htons(skb->len);
96
97	skb_dst_set(skb, dst);
98
99	udp6_set_csum(nocheck, skb, saddr, daddr, skb->len);
100
101	__skb_push(skb, sizeof(*ip6h));
102	skb_reset_network_header(skb);
103	ip6h		  = ipv6_hdr(skb);
104	ip6_flow_hdr(ip6h, prio, label);
105	ip6h->payload_len = htons(skb->len);
106	ip6h->nexthdr     = IPPROTO_UDP;
107	ip6h->hop_limit   = ttl;
108	ip6h->daddr	  = *daddr;
109	ip6h->saddr	  = *saddr;
110
111	ip6tunnel_xmit(sk, skb, dev);
112	return 0;
113}
114EXPORT_SYMBOL_GPL(udp_tunnel6_xmit_skb);
115
116/**
117 *      udp_tunnel6_dst_lookup - perform route lookup on UDP tunnel
118 *      @skb: Packet for which lookup is done
119 *      @dev: Tunnel device
120 *      @net: Network namespace of tunnel device
121 *      @sock: Socket which provides route info
122 *      @oif: Index of the output interface
123 *      @saddr: Memory to store the src ip address
124 *      @key: Tunnel information
125 *      @sport: UDP source port
126 *      @dport: UDP destination port
127 *      @dsfield: The traffic class field
128 *      @dst_cache: The dst cache to use for lookup
129 *      This function performs a route lookup on a UDP tunnel
130 *
131 *      It returns a valid dst pointer and stores src address to be used in
132 *      tunnel in param saddr on success, else a pointer encoded error code.
133 */
134
135struct dst_entry *udp_tunnel6_dst_lookup(struct sk_buff *skb,
136					 struct net_device *dev,
137					 struct net *net,
138					 struct socket *sock,
139					 int oif,
140					 struct in6_addr *saddr,
141					 const struct ip_tunnel_key *key,
142					 __be16 sport, __be16 dport, u8 dsfield,
143					 struct dst_cache *dst_cache)
144{
145	struct dst_entry *dst = NULL;
146	struct flowi6 fl6;
147
148#ifdef CONFIG_DST_CACHE
149	if (dst_cache) {
150		dst = dst_cache_get_ip6(dst_cache, saddr);
151		if (dst)
152			return dst;
153	}
154#endif
155	memset(&fl6, 0, sizeof(fl6));
156	fl6.flowi6_mark = skb->mark;
157	fl6.flowi6_proto = IPPROTO_UDP;
158	fl6.flowi6_oif = oif;
159	fl6.daddr = key->u.ipv6.dst;
160	fl6.saddr = key->u.ipv6.src;
161	fl6.fl6_sport = sport;
162	fl6.fl6_dport = dport;
163	fl6.flowlabel = ip6_make_flowinfo(dsfield, key->label);
164
165	dst = ipv6_stub->ipv6_dst_lookup_flow(net, sock->sk, &fl6,
166					      NULL);
167	if (IS_ERR(dst)) {
168		netdev_dbg(dev, "no route to %pI6\n", &fl6.daddr);
169		return ERR_PTR(-ENETUNREACH);
170	}
171	if (dst->dev == dev) { /* is this necessary? */
172		netdev_dbg(dev, "circular route to %pI6\n", &fl6.daddr);
173		dst_release(dst);
174		return ERR_PTR(-ELOOP);
175	}
176#ifdef CONFIG_DST_CACHE
177	if (dst_cache)
178		dst_cache_set_ip6(dst_cache, dst, &fl6.saddr);
179#endif
180	*saddr = fl6.saddr;
181	return dst;
182}
183EXPORT_SYMBOL_GPL(udp_tunnel6_dst_lookup);
184
185MODULE_DESCRIPTION("IPv6 Foo over UDP tunnel driver");
186MODULE_LICENSE("GPL");
187