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Commit 6a93cc90 authored by Andy Zhou's avatar Andy Zhou Committed by David S. Miller
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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: default avatarAndy Zhou <azhou@nicira.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent fd384412

include/net/udp_tunnel.h

+57 −0
Original line number Diff line number Diff line 
#ifndef __NET_UDP_TUNNEL_H

#define __NET_UDP_TUNNEL_H



#include <net/ip_tunnels.h>

#include <net/udp.h>



#if IS_ENABLED(CONFIG_IPV6)

#include <net/ipv6.h>

#include <net/addrconf.h>

#endif



struct udp_port_cfg {

	u8			family;
@@ -53,4 +61,53 @@ static inline int udp_sock_create(struct net *net, 
	return -EPFNOSUPPORT;

}



typedef int (*udp_tunnel_encap_rcv_t)(struct sock *sk, struct sk_buff *skb);

typedef void (*udp_tunnel_encap_destroy_t)(struct sock *sk);



struct udp_tunnel_sock_cfg {

	void *sk_user_data;     /* user data used by encap_rcv call back */

	/* Used for setting up udp_sock fields, see udp.h for details */

	__u8  encap_type;

	udp_tunnel_encap_rcv_t encap_rcv;

	udp_tunnel_encap_destroy_t encap_destroy;

};



/* Setup the given (UDP) sock to receive UDP encapsulated packets */

void setup_udp_tunnel_sock(struct net *net, struct socket *sock,

			   struct udp_tunnel_sock_cfg *sock_cfg);



/* Transmit the skb using UDP encapsulation. */

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);



#if IS_ENABLED(CONFIG_IPV6)

int udp_tunnel6_xmit_skb(struct socket *sock, struct dst_entry *dst,

			 struct sk_buff *skb, struct net_device *dev,

			 struct in6_addr *saddr, struct in6_addr *daddr,

			 __u8 prio, __u8 ttl, __be16 src_port,

			 __be16 dst_port);

#endif



void udp_tunnel_sock_release(struct socket *sock);



static inline struct sk_buff *udp_tunnel_handle_offloads(struct sk_buff *skb,

							 bool udp_csum)

{

	int type = udp_csum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;



	return iptunnel_handle_offloads(skb, udp_csum, type);

}



static inline void udp_tunnel_encap_enable(struct socket *sock)

{

#if IS_ENABLED(CONFIG_IPV6)

	if (sock->sk->sk_family == PF_INET6)

		ipv6_stub->udpv6_encap_enable();

	else

#endif

		udp_encap_enable();

}



#endif

net/ipv4/udp_tunnel.c

+52 −1
Original line number Diff line number Diff line
@@ -11,7 +11,7 @@ 
int udp_sock_create4(struct net *net, struct udp_port_cfg *cfg,

		     struct socket **sockp)

{

	int err = -EINVAL;

	int err;

	struct socket *sock = NULL;

	struct sockaddr_in udp_addr;
@@ -54,4 +54,55 @@ int udp_sock_create4(struct net *net, struct udp_port_cfg *cfg, 
}

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");

net/ipv6/ip6_udp_tunnel.c

+42 −0
Original line number Diff line number Diff line
@@ -61,3 +61,45 @@ int udp_sock_create6(struct net *net, struct udp_port_cfg *cfg, 
	return err;

}

EXPORT_SYMBOL_GPL(udp_sock_create6);



int udp_tunnel6_xmit_skb(struct socket *sock, struct dst_entry *dst,

			 struct sk_buff *skb, struct net_device *dev,

			 struct in6_addr *saddr, struct in6_addr *daddr,

			 __u8 prio, __u8 ttl, __be16 src_port, __be16 dst_port)

{

	struct udphdr *uh;

	struct ipv6hdr *ip6h;

	struct sock *sk = sock->sk;



	__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);

	uh->check = 0;



	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));

	IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED

			    | IPSKB_REROUTED);

	skb_dst_set(skb, dst);



	udp6_set_csum(udp_get_no_check6_tx(sk), skb, &inet6_sk(sk)->saddr,

		      &sk->sk_v6_daddr, skb->len);



	__skb_push(skb, sizeof(*ip6h));

	skb_reset_network_header(skb);

	ip6h		  = ipv6_hdr(skb);

	ip6_flow_hdr(ip6h, prio, htonl(0));

	ip6h->payload_len = htons(skb->len);

	ip6h->nexthdr     = IPPROTO_UDP;

	ip6h->hop_limit   = ttl;

	ip6h->daddr	  = *daddr;

	ip6h->saddr	  = *saddr;



	ip6tunnel_xmit(skb, dev);

	return 0;

}

EXPORT_SYMBOL_GPL(udp_tunnel6_xmit_skb);