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/kernel.h>
6 #include <net/dst_metadata.h>
7 #include <net/udp.h>
8 #include <net/udp_tunnel.h>
9
udp_sock_create4(struct net * net,struct udp_port_cfg * cfg,struct socket ** sockp)10 int udp_sock_create4(struct net *net, struct udp_port_cfg *cfg,
11 struct socket **sockp)
12 {
13 int err;
14 struct socket *sock = NULL;
15 struct sockaddr_in udp_addr;
16
17 err = sock_create_kern(net, AF_INET, SOCK_DGRAM, 0, &sock);
18 if (err < 0)
19 goto error;
20
21 if (cfg->bind_ifindex) {
22 err = sock_bindtoindex(sock->sk, cfg->bind_ifindex, true);
23 if (err < 0)
24 goto error;
25 }
26
27 udp_addr.sin_family = AF_INET;
28 udp_addr.sin_addr = cfg->local_ip;
29 udp_addr.sin_port = cfg->local_udp_port;
30 err = kernel_bind(sock, (struct sockaddr *)&udp_addr,
31 sizeof(udp_addr));
32 if (err < 0)
33 goto error;
34
35 if (cfg->peer_udp_port) {
36 udp_addr.sin_family = AF_INET;
37 udp_addr.sin_addr = cfg->peer_ip;
38 udp_addr.sin_port = cfg->peer_udp_port;
39 err = kernel_connect(sock, (struct sockaddr *)&udp_addr,
40 sizeof(udp_addr), 0);
41 if (err < 0)
42 goto error;
43 }
44
45 sock->sk->sk_no_check_tx = !cfg->use_udp_checksums;
46
47 *sockp = sock;
48 return 0;
49
50 error:
51 if (sock) {
52 kernel_sock_shutdown(sock, SHUT_RDWR);
53 sock_release(sock);
54 }
55 *sockp = NULL;
56 return err;
57 }
58 EXPORT_SYMBOL(udp_sock_create4);
59
setup_udp_tunnel_sock(struct net * net,struct socket * sock,struct udp_tunnel_sock_cfg * cfg)60 void setup_udp_tunnel_sock(struct net *net, struct socket *sock,
61 struct udp_tunnel_sock_cfg *cfg)
62 {
63 struct sock *sk = sock->sk;
64
65 /* Disable multicast loopback */
66 inet_clear_bit(MC_LOOP, sk);
67
68 /* Enable CHECKSUM_UNNECESSARY to CHECKSUM_COMPLETE conversion */
69 inet_inc_convert_csum(sk);
70
71 rcu_assign_sk_user_data(sk, cfg->sk_user_data);
72
73 udp_sk(sk)->encap_type = cfg->encap_type;
74 udp_sk(sk)->encap_rcv = cfg->encap_rcv;
75 udp_sk(sk)->encap_err_rcv = cfg->encap_err_rcv;
76 udp_sk(sk)->encap_err_lookup = cfg->encap_err_lookup;
77 udp_sk(sk)->encap_destroy = cfg->encap_destroy;
78 udp_sk(sk)->gro_receive = cfg->gro_receive;
79 udp_sk(sk)->gro_complete = cfg->gro_complete;
80
81 udp_tunnel_encap_enable(sk);
82 }
83 EXPORT_SYMBOL_GPL(setup_udp_tunnel_sock);
84
udp_tunnel_push_rx_port(struct net_device * dev,struct socket * sock,unsigned short type)85 void udp_tunnel_push_rx_port(struct net_device *dev, struct socket *sock,
86 unsigned short type)
87 {
88 struct sock *sk = sock->sk;
89 struct udp_tunnel_info ti;
90
91 ti.type = type;
92 ti.sa_family = sk->sk_family;
93 ti.port = inet_sk(sk)->inet_sport;
94
95 udp_tunnel_nic_add_port(dev, &ti);
96 }
97 EXPORT_SYMBOL_GPL(udp_tunnel_push_rx_port);
98
udp_tunnel_drop_rx_port(struct net_device * dev,struct socket * sock,unsigned short type)99 void udp_tunnel_drop_rx_port(struct net_device *dev, struct socket *sock,
100 unsigned short type)
101 {
102 struct sock *sk = sock->sk;
103 struct udp_tunnel_info ti;
104
105 ti.type = type;
106 ti.sa_family = sk->sk_family;
107 ti.port = inet_sk(sk)->inet_sport;
108
109 udp_tunnel_nic_del_port(dev, &ti);
110 }
111 EXPORT_SYMBOL_GPL(udp_tunnel_drop_rx_port);
112
113 /* Notify netdevs that UDP port started listening */
udp_tunnel_notify_add_rx_port(struct socket * sock,unsigned short type)114 void udp_tunnel_notify_add_rx_port(struct socket *sock, unsigned short type)
115 {
116 struct sock *sk = sock->sk;
117 struct net *net = sock_net(sk);
118 struct udp_tunnel_info ti;
119 struct net_device *dev;
120
121 ti.type = type;
122 ti.sa_family = sk->sk_family;
123 ti.port = inet_sk(sk)->inet_sport;
124
125 rcu_read_lock();
126 for_each_netdev_rcu(net, dev) {
127 udp_tunnel_nic_add_port(dev, &ti);
128 }
129 rcu_read_unlock();
130 }
131 EXPORT_SYMBOL_GPL(udp_tunnel_notify_add_rx_port);
132
133 /* Notify netdevs that UDP port is no more listening */
udp_tunnel_notify_del_rx_port(struct socket * sock,unsigned short type)134 void udp_tunnel_notify_del_rx_port(struct socket *sock, unsigned short type)
135 {
136 struct sock *sk = sock->sk;
137 struct net *net = sock_net(sk);
138 struct udp_tunnel_info ti;
139 struct net_device *dev;
140
141 ti.type = type;
142 ti.sa_family = sk->sk_family;
143 ti.port = inet_sk(sk)->inet_sport;
144
145 rcu_read_lock();
146 for_each_netdev_rcu(net, dev) {
147 udp_tunnel_nic_del_port(dev, &ti);
148 }
149 rcu_read_unlock();
150 }
151 EXPORT_SYMBOL_GPL(udp_tunnel_notify_del_rx_port);
152
udp_tunnel_xmit_skb(struct rtable * rt,struct sock * sk,struct sk_buff * skb,__be32 src,__be32 dst,__u8 tos,__u8 ttl,__be16 df,__be16 src_port,__be16 dst_port,bool xnet,bool nocheck)153 void udp_tunnel_xmit_skb(struct rtable *rt, struct sock *sk, struct sk_buff *skb,
154 __be32 src, __be32 dst, __u8 tos, __u8 ttl,
155 __be16 df, __be16 src_port, __be16 dst_port,
156 bool xnet, bool nocheck)
157 {
158 struct udphdr *uh;
159
160 __skb_push(skb, sizeof(*uh));
161 skb_reset_transport_header(skb);
162 uh = udp_hdr(skb);
163
164 uh->dest = dst_port;
165 uh->source = src_port;
166 uh->len = htons(skb->len);
167
168 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
169
170 udp_set_csum(nocheck, skb, src, dst, skb->len);
171
172 iptunnel_xmit(sk, rt, skb, src, dst, IPPROTO_UDP, tos, ttl, df, xnet);
173 }
174 EXPORT_SYMBOL_GPL(udp_tunnel_xmit_skb);
175
udp_tunnel_sock_release(struct socket * sock)176 void udp_tunnel_sock_release(struct socket *sock)
177 {
178 rcu_assign_sk_user_data(sock->sk, NULL);
179 synchronize_rcu();
180 kernel_sock_shutdown(sock, SHUT_RDWR);
181 sock_release(sock);
182 }
183 EXPORT_SYMBOL_GPL(udp_tunnel_sock_release);
184
udp_tun_rx_dst(struct sk_buff * skb,unsigned short family,const unsigned long * flags,__be64 tunnel_id,int md_size)185 struct metadata_dst *udp_tun_rx_dst(struct sk_buff *skb, unsigned short family,
186 const unsigned long *flags,
187 __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 __set_bit(IP_TUNNEL_CSUM_BIT, info->key.tun_flags);
204 return tun_dst;
205 }
206 EXPORT_SYMBOL_GPL(udp_tun_rx_dst);
207
udp_tunnel_dst_lookup(struct sk_buff * skb,struct net_device * dev,struct net * net,int oif,__be32 * saddr,const struct ip_tunnel_key * key,__be16 sport,__be16 dport,u8 tos,struct dst_cache * dst_cache)208 struct rtable *udp_tunnel_dst_lookup(struct sk_buff *skb,
209 struct net_device *dev,
210 struct net *net, int oif,
211 __be32 *saddr,
212 const struct ip_tunnel_key *key,
213 __be16 sport, __be16 dport, u8 tos,
214 struct dst_cache *dst_cache)
215 {
216 struct rtable *rt = NULL;
217 struct flowi4 fl4;
218
219 #ifdef CONFIG_DST_CACHE
220 if (dst_cache) {
221 rt = dst_cache_get_ip4(dst_cache, saddr);
222 if (rt)
223 return rt;
224 }
225 #endif
226
227 memset(&fl4, 0, sizeof(fl4));
228 fl4.flowi4_mark = skb->mark;
229 fl4.flowi4_proto = IPPROTO_UDP;
230 fl4.flowi4_oif = oif;
231 fl4.daddr = key->u.ipv4.dst;
232 fl4.saddr = key->u.ipv4.src;
233 fl4.fl4_dport = dport;
234 fl4.fl4_sport = sport;
235 fl4.flowi4_tos = RT_TOS(tos);
236 fl4.flowi4_flags = key->flow_flags;
237
238 rt = ip_route_output_key(net, &fl4);
239 if (IS_ERR(rt)) {
240 netdev_dbg(dev, "no route to %pI4\n", &fl4.daddr);
241 return ERR_PTR(-ENETUNREACH);
242 }
243 if (rt->dst.dev == dev) { /* is this necessary? */
244 netdev_dbg(dev, "circular route to %pI4\n", &fl4.daddr);
245 ip_rt_put(rt);
246 return ERR_PTR(-ELOOP);
247 }
248 #ifdef CONFIG_DST_CACHE
249 if (dst_cache)
250 dst_cache_set_ip4(dst_cache, &rt->dst, fl4.saddr);
251 #endif
252 *saddr = fl4.saddr;
253 return rt;
254 }
255 EXPORT_SYMBOL_GPL(udp_tunnel_dst_lookup);
256
257 MODULE_DESCRIPTION("IPv4 Foo over UDP tunnel driver");
258 MODULE_LICENSE("GPL");
259