net/ipv4/udp_tunnel.c

   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/dst_metadata.h>
   8 #include <net/net_namespace.h>
   9 #include <net/udp.h>
  10 #include <net/udp_tunnel.h>
  11
  12 int udp_sock_create4(struct net *net, struct udp_port_cfg *cfg,
  13                      struct socket **sockp)
  14 {
  15         int err;
  16         struct socket *sock = NULL;
  17         struct sockaddr_in udp_addr;
  18
  19         err = sock_create_kern(net, AF_INET, SOCK_DGRAM, 0, &sock);
  20         if (err < 0)
  21                 goto error;
  22
  23         if (cfg->bind_ifindex) {
  24                 struct net_device *dev;
  25
  26                 dev = dev_get_by_index(net, cfg->bind_ifindex);
  27                 if (!dev) {
  28                         err = -ENODEV;
  29                         goto error;
  30                 }
  31
  32                 err = kernel_setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE,
  33                                         dev->name, strlen(dev->name) + 1);
  34                 dev_put(dev);
  35
  36                 if (err < 0)
  37                         goto error;
  38         }
  39
  40         udp_addr.sin_family = AF_INET;
  41         udp_addr.sin_addr = cfg->local_ip;
  42         udp_addr.sin_port = cfg->local_udp_port;
  43         err = kernel_bind(sock, (struct sockaddr *)&udp_addr,
  44                           sizeof(udp_addr));
  45         if (err < 0)
  46                 goto error;
  47
  48         if (cfg->peer_udp_port) {
  49                 udp_addr.sin_family = AF_INET;
  50                 udp_addr.sin_addr = cfg->peer_ip;
  51                 udp_addr.sin_port = cfg->peer_udp_port;
  52                 err = kernel_connect(sock, (struct sockaddr *)&udp_addr,
  53                                      sizeof(udp_addr), 0);
  54                 if (err < 0)
  55                         goto error;
  56         }
  57
  58         sock->sk->sk_no_check_tx = !cfg->use_udp_checksums;
  59
  60         *sockp = sock;
  61         return 0;
  62
  63 error:
  64         if (sock) {
  65                 kernel_sock_shutdown(sock, SHUT_RDWR);
  66                 sock_release(sock);
  67         }
  68         *sockp = NULL;
  69         return err;
  70 }
  71 EXPORT_SYMBOL(udp_sock_create4);
  72
  73 void setup_udp_tunnel_sock(struct net *net, struct socket *sock,
  74                            struct udp_tunnel_sock_cfg *cfg)
  75 {
  76         struct sock *sk = sock->sk;
  77
  78         /* Disable multicast loopback */
  79         inet_sk(sk)->mc_loop = 0;
  80
  81         /* Enable CHECKSUM_UNNECESSARY to CHECKSUM_COMPLETE conversion */
  82         inet_inc_convert_csum(sk);
  83
  84         rcu_assign_sk_user_data(sk, cfg->sk_user_data);
  85
  86         udp_sk(sk)->encap_type = cfg->encap_type;
  87         udp_sk(sk)->encap_rcv = cfg->encap_rcv;
  88         udp_sk(sk)->encap_err_lookup = cfg->encap_err_lookup;
  89         udp_sk(sk)->encap_destroy = cfg->encap_destroy;
  90         udp_sk(sk)->gro_receive = cfg->gro_receive;
  91         udp_sk(sk)->gro_complete = cfg->gro_complete;
  92
  93         udp_tunnel_encap_enable(sock);
  94 }
  95 EXPORT_SYMBOL_GPL(setup_udp_tunnel_sock);
  96
  97 void udp_tunnel_push_rx_port(struct net_device *dev, struct socket *sock,
  98                              unsigned short type)
  99 {
 100         struct sock *sk = sock->sk;
 101         struct udp_tunnel_info ti;
 102
 103         if (!dev->netdev_ops->ndo_udp_tunnel_add ||
 104             !(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
 105                 return;
 106
 107         ti.type = type;
 108         ti.sa_family = sk->sk_family;
 109         ti.port = inet_sk(sk)->inet_sport;
 110
 111         dev->netdev_ops->ndo_udp_tunnel_add(dev, &ti);
 112 }
 113 EXPORT_SYMBOL_GPL(udp_tunnel_push_rx_port);
 114
 115 void udp_tunnel_drop_rx_port(struct net_device *dev, struct socket *sock,
 116                              unsigned short type)
 117 {
 118         struct sock *sk = sock->sk;
 119         struct udp_tunnel_info ti;
 120
 121         if (!dev->netdev_ops->ndo_udp_tunnel_del ||
 122             !(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
 123                 return;
 124
 125         ti.type = type;
 126         ti.sa_family = sk->sk_family;
 127         ti.port = inet_sk(sk)->inet_sport;
 128
 129         dev->netdev_ops->ndo_udp_tunnel_del(dev, &ti);
 130 }
 131 EXPORT_SYMBOL_GPL(udp_tunnel_drop_rx_port);
 132
 133 /* Notify netdevs that UDP port started listening */
 134 void udp_tunnel_notify_add_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                 if (!dev->netdev_ops->ndo_udp_tunnel_add)
 148                         continue;
 149                 if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
 150                         continue;
 151                 dev->netdev_ops->ndo_udp_tunnel_add(dev, &ti);
 152         }
 153         rcu_read_unlock();
 154 }
 155 EXPORT_SYMBOL_GPL(udp_tunnel_notify_add_rx_port);
 156
 157 /* Notify netdevs that UDP port is no more listening */
 158 void udp_tunnel_notify_del_rx_port(struct socket *sock, unsigned short type)
 159 {
 160         struct sock *sk = sock->sk;
 161         struct net *net = sock_net(sk);
 162         struct udp_tunnel_info ti;
 163         struct net_device *dev;
 164
 165         ti.type = type;
 166         ti.sa_family = sk->sk_family;
 167         ti.port = inet_sk(sk)->inet_sport;
 168
 169         rcu_read_lock();
 170         for_each_netdev_rcu(net, dev) {
 171                 if (!dev->netdev_ops->ndo_udp_tunnel_del)
 172                         continue;
 173                 if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
 174                         continue;
 175                 dev->netdev_ops->ndo_udp_tunnel_del(dev, &ti);
 176         }
 177         rcu_read_unlock();
 178 }
 179 EXPORT_SYMBOL_GPL(udp_tunnel_notify_del_rx_port);
 180
 181 void udp_tunnel_xmit_skb(struct rtable *rt, struct sock *sk, struct sk_buff *skb,
 182                          __be32 src, __be32 dst, __u8 tos, __u8 ttl,
 183                          __be16 df, __be16 src_port, __be16 dst_port,
 184                          bool xnet, bool nocheck)
 185 {
 186         struct udphdr *uh;
 187
 188         __skb_push(skb, sizeof(*uh));
 189         skb_reset_transport_header(skb);
 190         uh = udp_hdr(skb);
 191
 192         uh->dest = dst_port;
 193         uh->source = src_port;
 194         uh->len = htons(skb->len);
 195
 196         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
 197
 198         udp_set_csum(nocheck, skb, src, dst, skb->len);
 199
 200         iptunnel_xmit(sk, rt, skb, src, dst, IPPROTO_UDP, tos, ttl, df, xnet);
 201 }
 202 EXPORT_SYMBOL_GPL(udp_tunnel_xmit_skb);
 203
 204 void udp_tunnel_sock_release(struct socket *sock)
 205 {
 206         rcu_assign_sk_user_data(sock->sk, NULL);
 207         kernel_sock_shutdown(sock, SHUT_RDWR);
 208         sock_release(sock);
 209 }
 210 EXPORT_SYMBOL_GPL(udp_tunnel_sock_release);
 211
 212 struct metadata_dst *udp_tun_rx_dst(struct sk_buff *skb,  unsigned short family,
 213                                     __be16 flags, __be64 tunnel_id, int md_size)
 214 {
 215         struct metadata_dst *tun_dst;
 216         struct ip_tunnel_info *info;
 217
 218         if (family == AF_INET)
 219                 tun_dst = ip_tun_rx_dst(skb, flags, tunnel_id, md_size);
 220         else
 221                 tun_dst = ipv6_tun_rx_dst(skb, flags, tunnel_id, md_size);
 222         if (!tun_dst)
 223                 return NULL;
 224
 225         info = &tun_dst->u.tun_info;
 226         info->key.tp_src = udp_hdr(skb)->source;
 227         info->key.tp_dst = udp_hdr(skb)->dest;
 228         if (udp_hdr(skb)->check)
 229                 info->key.tun_flags |= TUNNEL_CSUM;
 230         return tun_dst;
 231 }
 232 EXPORT_SYMBOL_GPL(udp_tun_rx_dst);
 233
 234 MODULE_LICENSE("GPL");