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