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         udp_addr.sin_family = AF_INET;
  24         udp_addr.sin_addr = cfg->local_ip;
  25         udp_addr.sin_port = cfg->local_udp_port;
  26         err = kernel_bind(sock, (struct sockaddr *)&udp_addr,
  27                           sizeof(udp_addr));
  28         if (err < 0)
  29                 goto error;
  30
  31         if (cfg->peer_udp_port) {
  32                 udp_addr.sin_family = AF_INET;
  33                 udp_addr.sin_addr = cfg->peer_ip;
  34                 udp_addr.sin_port = cfg->peer_udp_port;
  35                 err = kernel_connect(sock, (struct sockaddr *)&udp_addr,
  36                                      sizeof(udp_addr), 0);
  37                 if (err < 0)
  38                         goto error;
  39         }
  40
  41         sock->sk->sk_no_check_tx = !cfg->use_udp_checksums;
  42
  43         *sockp = sock;
  44         return 0;
  45
  46 error:
  47         if (sock) {
  48                 kernel_sock_shutdown(sock, SHUT_RDWR);
  49                 sock_release(sock);
  50         }
  51         *sockp = NULL;
  52         return err;
  53 }
  54 EXPORT_SYMBOL(udp_sock_create4);
  55
  56 void setup_udp_tunnel_sock(struct net *net, struct socket *sock,
  57                            struct udp_tunnel_sock_cfg *cfg)
  58 {
  59         struct sock *sk = sock->sk;
  60
  61         /* Disable multicast loopback */
  62         inet_sk(sk)->mc_loop = 0;
  63
  64         /* Enable CHECKSUM_UNNECESSARY to CHECKSUM_COMPLETE conversion */
  65         inet_inc_convert_csum(sk);
  66
  67         rcu_assign_sk_user_data(sk, cfg->sk_user_data);
  68
  69         udp_sk(sk)->encap_type = cfg->encap_type;
  70         udp_sk(sk)->encap_rcv = cfg->encap_rcv;
  71         udp_sk(sk)->encap_destroy = cfg->encap_destroy;
  72
  73         udp_tunnel_encap_enable(sock);
  74 }
  75 EXPORT_SYMBOL_GPL(setup_udp_tunnel_sock);
  76
  77 int udp_tunnel_xmit_skb(struct rtable *rt, struct sock *sk, struct sk_buff *skb,
  78                         __be32 src, __be32 dst, __u8 tos, __u8 ttl,
  79                         __be16 df, __be16 src_port, __be16 dst_port,
  80                         bool xnet, bool nocheck)
  81 {
  82         struct udphdr *uh;
  83
  84         __skb_push(skb, sizeof(*uh));
  85         skb_reset_transport_header(skb);
  86         uh = udp_hdr(skb);
  87
  88         uh->dest = dst_port;
  89         uh->source = src_port;
  90         uh->len = htons(skb->len);
  91
  92         udp_set_csum(nocheck, skb, src, dst, skb->len);
  93
  94         return iptunnel_xmit(sk, rt, skb, src, dst, IPPROTO_UDP,
  95                              tos, ttl, df, xnet);
  96 }
  97 EXPORT_SYMBOL_GPL(udp_tunnel_xmit_skb);
  98
  99 void udp_tunnel_sock_release(struct socket *sock)
 100 {
 101         rcu_assign_sk_user_data(sock->sk, NULL);
 102         kernel_sock_shutdown(sock, SHUT_RDWR);
 103         sock_release(sock);
 104 }
 105 EXPORT_SYMBOL_GPL(udp_tunnel_sock_release);
 106
 107 struct metadata_dst *udp_tun_rx_dst(struct sk_buff *skb,  unsigned short family,
 108                                     __be16 flags, __be64 tunnel_id, int md_size)
 109 {
 110         struct metadata_dst *tun_dst;
 111         struct ip_tunnel_info *info;
 112
 113         if (family == AF_INET)
 114                 tun_dst = ip_tun_rx_dst(skb, flags, tunnel_id, md_size);
 115         else
 116                 tun_dst = ipv6_tun_rx_dst(skb, flags, tunnel_id, md_size);
 117         if (!tun_dst)
 118                 return NULL;
 119
 120         info = &tun_dst->u.tun_info;
 121         info->key.tp_src = udp_hdr(skb)->source;
 122         info->key.tp_dst = udp_hdr(skb)->dest;
 123         if (udp_hdr(skb)->check)
 124                 info->key.tun_flags |= TUNNEL_CSUM;
 125         return tun_dst;
 126 }
 127 EXPORT_SYMBOL_GPL(udp_tun_rx_dst);
 128
 129 MODULE_LICENSE("GPL");