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(AF_INET, SOCK_DGRAM, 0, &sock);
  19         if (err < 0)
  20                 goto error;
  21
  22         sk_change_net(sock->sk, net);
  23
  24         udp_addr.sin_family = AF_INET;
  25         udp_addr.sin_addr = cfg->local_ip;
  26         udp_addr.sin_port = cfg->local_udp_port;
  27         err = kernel_bind(sock, (struct sockaddr *)&udp_addr,
  28                           sizeof(udp_addr));
  29         if (err < 0)
  30                 goto error;
  31
  32         if (cfg->peer_udp_port) {
  33                 udp_addr.sin_family = AF_INET;
  34                 udp_addr.sin_addr = cfg->peer_ip;
  35                 udp_addr.sin_port = cfg->peer_udp_port;
  36                 err = kernel_connect(sock, (struct sockaddr *)&udp_addr,
  37                                      sizeof(udp_addr), 0);
  38                 if (err < 0)
  39                         goto error;
  40         }
  41
  42         sock->sk->sk_no_check_tx = !cfg->use_udp_checksums;
  43
  44         *sockp = sock;
  45         return 0;
  46
  47 error:
  48         if (sock) {
  49                 kernel_sock_shutdown(sock, SHUT_RDWR);
  50                 sk_release_kernel(sock->sk);
  51         }
  52         *sockp = NULL;
  53         return err;
  54 }
  55 EXPORT_SYMBOL(udp_sock_create4);
  56
  57 void setup_udp_tunnel_sock(struct net *net, struct socket *sock,
  58                            struct udp_tunnel_sock_cfg *cfg)
  59 {
  60         struct sock *sk = sock->sk;
  61
  62         /* Disable multicast loopback */
  63         inet_sk(sk)->mc_loop = 0;
  64
  65         /* Enable CHECKSUM_UNNECESSARY to CHECKSUM_COMPLETE conversion */
  66         udp_set_convert_csum(sk, true);
  67
  68         rcu_assign_sk_user_data(sk, cfg->sk_user_data);
  69
  70         udp_sk(sk)->encap_type = cfg->encap_type;
  71         udp_sk(sk)->encap_rcv = cfg->encap_rcv;
  72         udp_sk(sk)->encap_destroy = cfg->encap_destroy;
  73
  74         udp_tunnel_encap_enable(sock);
  75 }
  76 EXPORT_SYMBOL_GPL(setup_udp_tunnel_sock);
  77
  78 int udp_tunnel_xmit_skb(struct socket *sock, struct rtable *rt,
  79                         struct sk_buff *skb, __be32 src, __be32 dst,
  80                         __u8 tos, __u8 ttl, __be16 df, __be16 src_port,
  81                         __be16 dst_port, bool xnet)
  82 {
  83         struct udphdr *uh;
  84
  85         __skb_push(skb, sizeof(*uh));
  86         skb_reset_transport_header(skb);
  87         uh = udp_hdr(skb);
  88
  89         uh->dest = dst_port;
  90         uh->source = src_port;
  91         uh->len = htons(skb->len);
  92
  93         udp_set_csum(sock->sk->sk_no_check_tx, skb, src, dst, skb->len);
  94
  95         return iptunnel_xmit(sock->sk, rt, skb, src, dst, IPPROTO_UDP,
  96                              tos, ttl, df, xnet);
  97 }
  98 EXPORT_SYMBOL_GPL(udp_tunnel_xmit_skb);
  99
 100 void udp_tunnel_sock_release(struct socket *sock)
 101 {
 102         rcu_assign_sk_user_data(sock->sk, NULL);
 103         kernel_sock_shutdown(sock, SHUT_RDWR);
 104         sk_release_kernel(sock->sk);
 105 }
 106 EXPORT_SYMBOL_GPL(udp_tunnel_sock_release);
 107
 108 MODULE_LICENSE("GPL");