/* tunnel4.c: Generic IP tunnel transformer. * * Copyright (C) 2003 David S. Miller (davem@redhat.com) */ #include <linux/init.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/netdevice.h> #include <linux/skbuff.h> #include <net/icmp.h> #include <net/ip.h> #include <net/protocol.h> #include <net/xfrm.h> static struct xfrm_tunnel *tunnel4_handlers; static struct xfrm_tunnel *tunnel64_handlers; static DEFINE_MUTEX(tunnel4_mutex); int xfrm4_tunnel_register(struct xfrm_tunnel *handler, unsigned short family) { struct xfrm_tunnel **pprev; int ret = -EEXIST; int priority = handler->priority; mutex_lock(&tunnel4_mutex); for (pprev = (family == AF_INET) ? &tunnel4_handlers : &tunnel64_handlers; *pprev; pprev = &(*pprev)->next) { if ((*pprev)->priority > priority) break; if ((*pprev)->priority == priority) goto err; } handler->next = *pprev; *pprev = handler; ret = 0; err: mutex_unlock(&tunnel4_mutex); return ret; } EXPORT_SYMBOL(xfrm4_tunnel_register); int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler, unsigned short family) { struct xfrm_tunnel **pprev; int ret = -ENOENT; mutex_lock(&tunnel4_mutex); for (pprev = (family == AF_INET) ? &tunnel4_handlers : &tunnel64_handlers; *pprev; pprev = &(*pprev)->next) { if (*pprev == handler) { *pprev = handler->next; ret = 0; break; } } mutex_unlock(&tunnel4_mutex); synchronize_net(); return ret; } EXPORT_SYMBOL(xfrm4_tunnel_deregister); static int tunnel4_rcv(struct sk_buff *skb) { struct xfrm_tunnel *handler; if (!pskb_may_pull(skb, sizeof(struct iphdr))) goto drop; for (handler = tunnel4_handlers; handler; handler = handler->next) if (!handler->handler(skb)) return 0; icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); drop: kfree_skb(skb); return 0; } #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) static int tunnel64_rcv(struct sk_buff *skb) { struct xfrm_tunnel *handler; if (!pskb_may_pull(skb, sizeof(struct iphdr))) goto drop; for (handler = tunnel64_handlers; handler; handler = handler->next) if (!handler->handler(skb)) return 0; icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); drop: kfree_skb(skb); return 0; } #endif static void tunnel4_err(struct sk_buff *skb, u32 info) { struct xfrm_tunnel *handler; for (handler = tunnel4_handlers; handler; handler = handler->next) if (!handler->err_handler(skb, info)) break; } static struct net_protocol tunnel4_protocol = { .handler = tunnel4_rcv, .err_handler = tunnel4_err, .no_policy = 1, }; #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) static struct net_protocol tunnel64_protocol = { .handler = tunnel64_rcv, .err_handler = tunnel4_err, .no_policy = 1, }; #endif static int __init tunnel4_init(void) { if (inet_add_protocol(&tunnel4_protocol, IPPROTO_IPIP)) { printk(KERN_ERR "tunnel4 init: can't add protocol\n"); return -EAGAIN; } #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) if (inet_add_protocol(&tunnel64_protocol, IPPROTO_IPV6)) { printk(KERN_ERR "tunnel64 init: can't add protocol\n"); inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP); return -EAGAIN; } #endif return 0; } static void __exit tunnel4_fini(void) { #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) if (inet_del_protocol(&tunnel64_protocol, IPPROTO_IPV6)) printk(KERN_ERR "tunnel64 close: can't remove protocol\n"); #endif if (inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP)) printk(KERN_ERR "tunnel4 close: can't remove protocol\n"); } module_init(tunnel4_init); module_exit(tunnel4_fini); MODULE_LICENSE("GPL");