net/ipv4/udp_tunnel_core.c

   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 #include <net/inet_dscp.h>
  10
  11 int 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(net, AF_INET, SOCK_DGRAM, 0, &sock);
  19         if (err < 0)
  20                 goto error;
  21
  22         if (cfg->bind_ifindex) {
  23                 err = sock_bindtoindex(sock->sk, cfg->bind_ifindex, true);
  24                 if (err < 0)
  25                         goto error;
  26         }
  27
  28         udp_addr.sin_family = AF_INET;
  29         udp_addr.sin_addr = cfg->local_ip;
  30         udp_addr.sin_port = cfg->local_udp_port;
  31         err = kernel_bind(sock, (struct sockaddr *)&udp_addr,
  32                           sizeof(udp_addr));
  33         if (err < 0)
  34                 goto error;
  35
  36         if (cfg->peer_udp_port) {
  37                 udp_addr.sin_family = AF_INET;
  38                 udp_addr.sin_addr = cfg->peer_ip;
  39                 udp_addr.sin_port = cfg->peer_udp_port;
  40                 err = kernel_connect(sock, (struct sockaddr *)&udp_addr,
  41                                      sizeof(udp_addr), 0);
  42                 if (err < 0)
  43                         goto error;
  44         }
  45
  46         sock->sk->sk_no_check_tx = !cfg->use_udp_checksums;
  47
  48         *sockp = sock;
  49         return 0;
  50
  51 error:
  52         if (sock) {
  53                 kernel_sock_shutdown(sock, SHUT_RDWR);
  54                 sock_release(sock);
  55         }
  56         *sockp = NULL;
  57         return err;
  58 }
  59 EXPORT_SYMBOL(udp_sock_create4);
  60
  61 void setup_udp_tunnel_sock(struct net *net, struct socket *sock,
  62                            struct udp_tunnel_sock_cfg *cfg)
  63 {
  64         struct sock *sk = sock->sk;
  65
  66         /* Disable multicast loopback */
  67         inet_clear_bit(MC_LOOP, sk);
  68
  69         /* Enable CHECKSUM_UNNECESSARY to CHECKSUM_COMPLETE conversion */
  70         inet_inc_convert_csum(sk);
  71
  72         rcu_assign_sk_user_data(sk, cfg->sk_user_data);
  73
  74         udp_sk(sk)->encap_type = cfg->encap_type;
  75         udp_sk(sk)->encap_rcv = cfg->encap_rcv;
  76         udp_sk(sk)->encap_err_rcv = cfg->encap_err_rcv;
  77         udp_sk(sk)->encap_err_lookup = cfg->encap_err_lookup;
  78         udp_sk(sk)->encap_destroy = cfg->encap_destroy;
  79         udp_sk(sk)->gro_receive = cfg->gro_receive;
  80         udp_sk(sk)->gro_complete = cfg->gro_complete;
  81
  82         udp_tunnel_encap_enable(sk);
  83 }
  84 EXPORT_SYMBOL_GPL(setup_udp_tunnel_sock);
  85
  86 void udp_tunnel_push_rx_port(struct net_device *dev, struct socket *sock,
  87                              unsigned short type)
  88 {
  89         struct sock *sk = sock->sk;
  90         struct udp_tunnel_info ti;
  91
  92         ti.type = type;
  93         ti.sa_family = sk->sk_family;
  94         ti.port = inet_sk(sk)->inet_sport;
  95
  96         udp_tunnel_nic_add_port(dev, &ti);
  97 }
  98 EXPORT_SYMBOL_GPL(udp_tunnel_push_rx_port);
  99
 100 void udp_tunnel_drop_rx_port(struct net_device *dev, struct socket *sock,
 101                              unsigned short type)
 102 {
 103         struct sock *sk = sock->sk;
 104         struct udp_tunnel_info ti;
 105
 106         ti.type = type;
 107         ti.sa_family = sk->sk_family;
 108         ti.port = inet_sk(sk)->inet_sport;
 109
 110         udp_tunnel_nic_del_port(dev, &ti);
 111 }
 112 EXPORT_SYMBOL_GPL(udp_tunnel_drop_rx_port);
 113
 114 /* Notify netdevs that UDP port started listening */
 115 void udp_tunnel_notify_add_rx_port(struct socket *sock, unsigned short type)
 116 {
 117         struct sock *sk = sock->sk;
 118         struct net *net = sock_net(sk);
 119         struct udp_tunnel_info ti;
 120         struct net_device *dev;
 121
 122         ti.type = type;
 123         ti.sa_family = sk->sk_family;
 124         ti.port = inet_sk(sk)->inet_sport;
 125
 126         rcu_read_lock();
 127         for_each_netdev_rcu(net, dev) {
 128                 udp_tunnel_nic_add_port(dev, &ti);
 129         }
 130         rcu_read_unlock();
 131 }
 132 EXPORT_SYMBOL_GPL(udp_tunnel_notify_add_rx_port);
 133
 134 /* Notify netdevs that UDP port is no more listening */
 135 void udp_tunnel_notify_del_rx_port(struct socket *sock, unsigned short type)
 136 {
 137         struct sock *sk = sock->sk;
 138         struct net *net = sock_net(sk);
 139         struct udp_tunnel_info ti;
 140         struct net_device *dev;
 141
 142         ti.type = type;
 143         ti.sa_family = sk->sk_family;
 144         ti.port = inet_sk(sk)->inet_sport;
 145
 146         rcu_read_lock();
 147         for_each_netdev_rcu(net, dev) {
 148                 udp_tunnel_nic_del_port(dev, &ti);
 149         }
 150         rcu_read_unlock();
 151 }
 152 EXPORT_SYMBOL_GPL(udp_tunnel_notify_del_rx_port);
 153
 154 void udp_tunnel_xmit_skb(struct rtable *rt, struct sock *sk, struct sk_buff *skb,
 155                          __be32 src, __be32 dst, __u8 tos, __u8 ttl,
 156                          __be16 df, __be16 src_port, __be16 dst_port,
 157                          bool xnet, bool nocheck)
 158 {
 159         struct udphdr *uh;
 160
 161         __skb_push(skb, sizeof(*uh));
 162         skb_reset_transport_header(skb);
 163         uh = udp_hdr(skb);
 164
 165         uh->dest = dst_port;
 166         uh->source = src_port;
 167         uh->len = htons(skb->len);
 168
 169         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
 170
 171         udp_set_csum(nocheck, skb, src, dst, skb->len);
 172
 173         iptunnel_xmit(sk, rt, skb, src, dst, IPPROTO_UDP, tos, ttl, df, xnet);
 174 }
 175 EXPORT_SYMBOL_GPL(udp_tunnel_xmit_skb);
 176
 177 void udp_tunnel_sock_release(struct socket *sock)
 178 {
 179         rcu_assign_sk_user_data(sock->sk, NULL);
 180         synchronize_rcu();
 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                                     const unsigned long *flags,
 188                                     __be64 tunnel_id, int md_size)
 189 {
 190         struct metadata_dst *tun_dst;
 191         struct ip_tunnel_info *info;
 192
 193         if (family == AF_INET)
 194                 tun_dst = ip_tun_rx_dst(skb, flags, tunnel_id, md_size);
 195         else
 196                 tun_dst = ipv6_tun_rx_dst(skb, flags, tunnel_id, md_size);
 197         if (!tun_dst)
 198                 return NULL;
 199
 200         info = &tun_dst->u.tun_info;
 201         info->key.tp_src = udp_hdr(skb)->source;
 202         info->key.tp_dst = udp_hdr(skb)->dest;
 203         if (udp_hdr(skb)->check)
 204                 __set_bit(IP_TUNNEL_CSUM_BIT, info->key.tun_flags);
 205         return tun_dst;
 206 }
 207 EXPORT_SYMBOL_GPL(udp_tun_rx_dst);
 208
 209 struct rtable *udp_tunnel_dst_lookup(struct sk_buff *skb,
 210                                      struct net_device *dev,
 211                                      struct net *net, int oif,
 212                                      __be32 *saddr,
 213                                      const struct ip_tunnel_key *key,
 214                                      __be16 sport, __be16 dport, u8 tos,
 215                                      struct dst_cache *dst_cache)
 216 {
 217         struct rtable *rt = NULL;
 218         struct flowi4 fl4;
 219
 220 #ifdef CONFIG_DST_CACHE
 221         if (dst_cache) {
 222                 rt = dst_cache_get_ip4(dst_cache, saddr);
 223                 if (rt)
 224                         return rt;
 225         }
 226 #endif
 227
 228         memset(&fl4, 0, sizeof(fl4));
 229         fl4.flowi4_mark = skb->mark;
 230         fl4.flowi4_proto = IPPROTO_UDP;
 231         fl4.flowi4_oif = oif;
 232         fl4.daddr = key->u.ipv4.dst;
 233         fl4.saddr = key->u.ipv4.src;
 234         fl4.fl4_dport = dport;
 235         fl4.fl4_sport = sport;
 236         fl4.flowi4_tos = tos & INET_DSCP_MASK;
 237         fl4.flowi4_flags = key->flow_flags;
 238
 239         rt = ip_route_output_key(net, &fl4);
 240         if (IS_ERR(rt)) {
 241                 netdev_dbg(dev, "no route to %pI4\n", &fl4.daddr);
 242                 return ERR_PTR(-ENETUNREACH);
 243         }
 244         if (rt->dst.dev == dev) { /* is this necessary? */
 245                 netdev_dbg(dev, "circular route to %pI4\n", &fl4.daddr);
 246                 ip_rt_put(rt);
 247                 return ERR_PTR(-ELOOP);
 248         }
 249 #ifdef CONFIG_DST_CACHE
 250         if (dst_cache)
 251                 dst_cache_set_ip4(dst_cache, &rt->dst, fl4.saddr);
 252 #endif
 253         *saddr = fl4.saddr;
 254         return rt;
 255 }
 256 EXPORT_SYMBOL_GPL(udp_tunnel_dst_lookup);
 257
 258 MODULE_DESCRIPTION("IPv4 Foo over UDP tunnel driver");
 259 MODULE_LICENSE("GPL");