145 lines
2.8 KiB
C
145 lines
2.8 KiB
C
/* xfrm4_tunnel.c: Generic IP tunnel transformer.
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*
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* Copyright (C) 2003 David S. Miller (davem@redhat.com)
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*/
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#include <linux/skbuff.h>
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#include <linux/module.h>
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#include <net/xfrm.h>
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#include <net/ip.h>
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#include <net/protocol.h>
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static int ipip_output(struct xfrm_state *x, struct sk_buff *skb)
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{
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struct iphdr *iph;
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iph = skb->nh.iph;
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iph->tot_len = htons(skb->len);
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ip_send_check(iph);
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return 0;
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}
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static int ipip_xfrm_rcv(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb)
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{
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return 0;
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}
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static struct xfrm_tunnel *ipip_handler;
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static DECLARE_MUTEX(xfrm4_tunnel_sem);
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int xfrm4_tunnel_register(struct xfrm_tunnel *handler)
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{
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int ret;
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down(&xfrm4_tunnel_sem);
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ret = 0;
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if (ipip_handler != NULL)
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ret = -EINVAL;
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if (!ret)
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ipip_handler = handler;
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up(&xfrm4_tunnel_sem);
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return ret;
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}
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EXPORT_SYMBOL(xfrm4_tunnel_register);
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int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler)
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{
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int ret;
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down(&xfrm4_tunnel_sem);
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ret = 0;
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if (ipip_handler != handler)
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ret = -EINVAL;
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if (!ret)
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ipip_handler = NULL;
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up(&xfrm4_tunnel_sem);
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synchronize_net();
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return ret;
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}
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EXPORT_SYMBOL(xfrm4_tunnel_deregister);
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static int ipip_rcv(struct sk_buff *skb)
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{
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struct xfrm_tunnel *handler = ipip_handler;
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/* Tunnel devices take precedence. */
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if (handler && handler->handler(skb) == 0)
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return 0;
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return xfrm4_rcv(skb);
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}
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static void ipip_err(struct sk_buff *skb, u32 info)
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{
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struct xfrm_tunnel *handler = ipip_handler;
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u32 arg = info;
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if (handler)
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handler->err_handler(skb, &arg);
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}
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static int ipip_init_state(struct xfrm_state *x)
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{
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if (!x->props.mode)
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return -EINVAL;
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if (x->encap)
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return -EINVAL;
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x->props.header_len = sizeof(struct iphdr);
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return 0;
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}
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static void ipip_destroy(struct xfrm_state *x)
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{
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}
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static struct xfrm_type ipip_type = {
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.description = "IPIP",
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.owner = THIS_MODULE,
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.proto = IPPROTO_IPIP,
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.init_state = ipip_init_state,
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.destructor = ipip_destroy,
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.input = ipip_xfrm_rcv,
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.output = ipip_output
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};
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static struct net_protocol ipip_protocol = {
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.handler = ipip_rcv,
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.err_handler = ipip_err,
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.no_policy = 1,
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};
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static int __init ipip_init(void)
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{
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if (xfrm_register_type(&ipip_type, AF_INET) < 0) {
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printk(KERN_INFO "ipip init: can't add xfrm type\n");
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return -EAGAIN;
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}
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if (inet_add_protocol(&ipip_protocol, IPPROTO_IPIP) < 0) {
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printk(KERN_INFO "ipip init: can't add protocol\n");
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xfrm_unregister_type(&ipip_type, AF_INET);
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return -EAGAIN;
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}
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return 0;
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}
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static void __exit ipip_fini(void)
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{
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if (inet_del_protocol(&ipip_protocol, IPPROTO_IPIP) < 0)
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printk(KERN_INFO "ipip close: can't remove protocol\n");
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if (xfrm_unregister_type(&ipip_type, AF_INET) < 0)
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printk(KERN_INFO "ipip close: can't remove xfrm type\n");
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}
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module_init(ipip_init);
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module_exit(ipip_fini);
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MODULE_LICENSE("GPL");
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