linux/net/ipv4/udp_tunnel.c
Andy Zhou 6a93cc9052 udp-tunnel: Add a few more UDP tunnel APIs
Added a few more UDP tunnel APIs that can be shared by UDP based
tunnel protocol implementation. The main ones are highlighted below.

setup_udp_tunnel_sock() configures UDP listener socket for
receiving UDP encapsulated packets.

udp_tunnel_xmit_skb() and upd_tunnel6_xmit_skb() transmit skb
using UDP encapsulation.

udp_tunnel_sock_release() closes the UDP tunnel listener socket.

Signed-off-by: Andy Zhou <azhou@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-19 15:57:15 -04:00

108 lines
2.6 KiB
C

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/socket.h>
#include <linux/udp.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <net/udp.h>
#include <net/udp_tunnel.h>
#include <net/net_namespace.h>
int udp_sock_create4(struct net *net, struct udp_port_cfg *cfg,
struct socket **sockp)
{
int err;
struct socket *sock = NULL;
struct sockaddr_in udp_addr;
err = sock_create_kern(AF_INET, SOCK_DGRAM, 0, &sock);
if (err < 0)
goto error;
sk_change_net(sock->sk, net);
udp_addr.sin_family = AF_INET;
udp_addr.sin_addr = cfg->local_ip;
udp_addr.sin_port = cfg->local_udp_port;
err = kernel_bind(sock, (struct sockaddr *)&udp_addr,
sizeof(udp_addr));
if (err < 0)
goto error;
if (cfg->peer_udp_port) {
udp_addr.sin_family = AF_INET;
udp_addr.sin_addr = cfg->peer_ip;
udp_addr.sin_port = cfg->peer_udp_port;
err = kernel_connect(sock, (struct sockaddr *)&udp_addr,
sizeof(udp_addr), 0);
if (err < 0)
goto error;
}
sock->sk->sk_no_check_tx = !cfg->use_udp_checksums;
*sockp = sock;
return 0;
error:
if (sock) {
kernel_sock_shutdown(sock, SHUT_RDWR);
sk_release_kernel(sock->sk);
}
*sockp = NULL;
return err;
}
EXPORT_SYMBOL(udp_sock_create4);
void setup_udp_tunnel_sock(struct net *net, struct socket *sock,
struct udp_tunnel_sock_cfg *cfg)
{
struct sock *sk = sock->sk;
/* Disable multicast loopback */
inet_sk(sk)->mc_loop = 0;
/* Enable CHECKSUM_UNNECESSARY to CHECKSUM_COMPLETE conversion */
udp_set_convert_csum(sk, true);
rcu_assign_sk_user_data(sk, cfg->sk_user_data);
udp_sk(sk)->encap_type = cfg->encap_type;
udp_sk(sk)->encap_rcv = cfg->encap_rcv;
udp_sk(sk)->encap_destroy = cfg->encap_destroy;
udp_tunnel_encap_enable(sock);
}
EXPORT_SYMBOL_GPL(setup_udp_tunnel_sock);
int udp_tunnel_xmit_skb(struct socket *sock, struct rtable *rt,
struct sk_buff *skb, __be32 src, __be32 dst,
__u8 tos, __u8 ttl, __be16 df, __be16 src_port,
__be16 dst_port, bool xnet)
{
struct udphdr *uh;
__skb_push(skb, sizeof(*uh));
skb_reset_transport_header(skb);
uh = udp_hdr(skb);
uh->dest = dst_port;
uh->source = src_port;
uh->len = htons(skb->len);
udp_set_csum(sock->sk->sk_no_check_tx, skb, src, dst, skb->len);
return iptunnel_xmit(sock->sk, rt, skb, src, dst, IPPROTO_UDP,
tos, ttl, df, xnet);
}
EXPORT_SYMBOL_GPL(udp_tunnel_xmit_skb);
void udp_tunnel_sock_release(struct socket *sock)
{
rcu_assign_sk_user_data(sock->sk, NULL);
kernel_sock_shutdown(sock, SHUT_RDWR);
sk_release_kernel(sock->sk);
}
EXPORT_SYMBOL_GPL(udp_tunnel_sock_release);
MODULE_LICENSE("GPL");