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