11da177e4SLinus Torvalds /* xfrm4_tunnel.c: Generic IP tunnel transformer. 21da177e4SLinus Torvalds * 31da177e4SLinus Torvalds * Copyright (C) 2003 David S. Miller (davem@redhat.com) 41da177e4SLinus Torvalds */ 51da177e4SLinus Torvalds 61da177e4SLinus Torvalds #include <linux/skbuff.h> 71da177e4SLinus Torvalds #include <linux/module.h> 81da177e4SLinus Torvalds #include <net/xfrm.h> 91da177e4SLinus Torvalds #include <net/ip.h> 101da177e4SLinus Torvalds #include <net/protocol.h> 111da177e4SLinus Torvalds 121da177e4SLinus Torvalds static int ipip_output(struct xfrm_state *x, struct sk_buff *skb) 131da177e4SLinus Torvalds { 141da177e4SLinus Torvalds struct iphdr *iph; 151da177e4SLinus Torvalds 161da177e4SLinus Torvalds iph = skb->nh.iph; 171da177e4SLinus Torvalds iph->tot_len = htons(skb->len); 181da177e4SLinus Torvalds ip_send_check(iph); 191da177e4SLinus Torvalds 201da177e4SLinus Torvalds return 0; 211da177e4SLinus Torvalds } 221da177e4SLinus Torvalds 231da177e4SLinus Torvalds static int ipip_xfrm_rcv(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb) 241da177e4SLinus Torvalds { 251da177e4SLinus Torvalds return 0; 261da177e4SLinus Torvalds } 271da177e4SLinus Torvalds 281da177e4SLinus Torvalds static struct xfrm_tunnel *ipip_handler; 291da177e4SLinus Torvalds static DECLARE_MUTEX(xfrm4_tunnel_sem); 301da177e4SLinus Torvalds 311da177e4SLinus Torvalds int xfrm4_tunnel_register(struct xfrm_tunnel *handler) 321da177e4SLinus Torvalds { 331da177e4SLinus Torvalds int ret; 341da177e4SLinus Torvalds 351da177e4SLinus Torvalds down(&xfrm4_tunnel_sem); 361da177e4SLinus Torvalds ret = 0; 371da177e4SLinus Torvalds if (ipip_handler != NULL) 381da177e4SLinus Torvalds ret = -EINVAL; 391da177e4SLinus Torvalds if (!ret) 401da177e4SLinus Torvalds ipip_handler = handler; 411da177e4SLinus Torvalds up(&xfrm4_tunnel_sem); 421da177e4SLinus Torvalds 431da177e4SLinus Torvalds return ret; 441da177e4SLinus Torvalds } 451da177e4SLinus Torvalds 461da177e4SLinus Torvalds EXPORT_SYMBOL(xfrm4_tunnel_register); 471da177e4SLinus Torvalds 481da177e4SLinus Torvalds int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler) 491da177e4SLinus Torvalds { 501da177e4SLinus Torvalds int ret; 511da177e4SLinus Torvalds 521da177e4SLinus Torvalds down(&xfrm4_tunnel_sem); 531da177e4SLinus Torvalds ret = 0; 541da177e4SLinus Torvalds if (ipip_handler != handler) 551da177e4SLinus Torvalds ret = -EINVAL; 561da177e4SLinus Torvalds if (!ret) 571da177e4SLinus Torvalds ipip_handler = NULL; 581da177e4SLinus Torvalds up(&xfrm4_tunnel_sem); 591da177e4SLinus Torvalds 601da177e4SLinus Torvalds synchronize_net(); 611da177e4SLinus Torvalds 621da177e4SLinus Torvalds return ret; 631da177e4SLinus Torvalds } 641da177e4SLinus Torvalds 651da177e4SLinus Torvalds EXPORT_SYMBOL(xfrm4_tunnel_deregister); 661da177e4SLinus Torvalds 671da177e4SLinus Torvalds static int ipip_rcv(struct sk_buff *skb) 681da177e4SLinus Torvalds { 691da177e4SLinus Torvalds struct xfrm_tunnel *handler = ipip_handler; 701da177e4SLinus Torvalds 711da177e4SLinus Torvalds /* Tunnel devices take precedence. */ 721da177e4SLinus Torvalds if (handler && handler->handler(skb) == 0) 731da177e4SLinus Torvalds return 0; 741da177e4SLinus Torvalds 751da177e4SLinus Torvalds return xfrm4_rcv(skb); 761da177e4SLinus Torvalds } 771da177e4SLinus Torvalds 781da177e4SLinus Torvalds static void ipip_err(struct sk_buff *skb, u32 info) 791da177e4SLinus Torvalds { 801da177e4SLinus Torvalds struct xfrm_tunnel *handler = ipip_handler; 811da177e4SLinus Torvalds u32 arg = info; 821da177e4SLinus Torvalds 831da177e4SLinus Torvalds if (handler) 841da177e4SLinus Torvalds handler->err_handler(skb, &arg); 851da177e4SLinus Torvalds } 861da177e4SLinus Torvalds 8772cb6962SHerbert Xu static int ipip_init_state(struct xfrm_state *x) 881da177e4SLinus Torvalds { 891da177e4SLinus Torvalds if (!x->props.mode) 901da177e4SLinus Torvalds return -EINVAL; 911da177e4SLinus Torvalds 921da177e4SLinus Torvalds if (x->encap) 931da177e4SLinus Torvalds return -EINVAL; 941da177e4SLinus Torvalds 951da177e4SLinus Torvalds x->props.header_len = sizeof(struct iphdr); 961da177e4SLinus Torvalds 971da177e4SLinus Torvalds return 0; 981da177e4SLinus Torvalds } 991da177e4SLinus Torvalds 1001da177e4SLinus Torvalds static void ipip_destroy(struct xfrm_state *x) 1011da177e4SLinus Torvalds { 1021da177e4SLinus Torvalds } 1031da177e4SLinus Torvalds 1041da177e4SLinus Torvalds static struct xfrm_type ipip_type = { 1051da177e4SLinus Torvalds .description = "IPIP", 1061da177e4SLinus Torvalds .owner = THIS_MODULE, 1071da177e4SLinus Torvalds .proto = IPPROTO_IPIP, 1081da177e4SLinus Torvalds .init_state = ipip_init_state, 1091da177e4SLinus Torvalds .destructor = ipip_destroy, 1101da177e4SLinus Torvalds .input = ipip_xfrm_rcv, 1111da177e4SLinus Torvalds .output = ipip_output 1121da177e4SLinus Torvalds }; 1131da177e4SLinus Torvalds 1141da177e4SLinus Torvalds static struct net_protocol ipip_protocol = { 1151da177e4SLinus Torvalds .handler = ipip_rcv, 1161da177e4SLinus Torvalds .err_handler = ipip_err, 1171da177e4SLinus Torvalds .no_policy = 1, 1181da177e4SLinus Torvalds }; 1191da177e4SLinus Torvalds 1201da177e4SLinus Torvalds static int __init ipip_init(void) 1211da177e4SLinus Torvalds { 1221da177e4SLinus Torvalds if (xfrm_register_type(&ipip_type, AF_INET) < 0) { 1231da177e4SLinus Torvalds printk(KERN_INFO "ipip init: can't add xfrm type\n"); 1241da177e4SLinus Torvalds return -EAGAIN; 1251da177e4SLinus Torvalds } 1261da177e4SLinus Torvalds if (inet_add_protocol(&ipip_protocol, IPPROTO_IPIP) < 0) { 1271da177e4SLinus Torvalds printk(KERN_INFO "ipip init: can't add protocol\n"); 1281da177e4SLinus Torvalds xfrm_unregister_type(&ipip_type, AF_INET); 1291da177e4SLinus Torvalds return -EAGAIN; 1301da177e4SLinus Torvalds } 1311da177e4SLinus Torvalds return 0; 1321da177e4SLinus Torvalds } 1331da177e4SLinus Torvalds 1341da177e4SLinus Torvalds static void __exit ipip_fini(void) 1351da177e4SLinus Torvalds { 1361da177e4SLinus Torvalds if (inet_del_protocol(&ipip_protocol, IPPROTO_IPIP) < 0) 1371da177e4SLinus Torvalds printk(KERN_INFO "ipip close: can't remove protocol\n"); 1381da177e4SLinus Torvalds if (xfrm_unregister_type(&ipip_type, AF_INET) < 0) 1391da177e4SLinus Torvalds printk(KERN_INFO "ipip close: can't remove xfrm type\n"); 1401da177e4SLinus Torvalds } 1411da177e4SLinus Torvalds 1421da177e4SLinus Torvalds module_init(ipip_init); 1431da177e4SLinus Torvalds module_exit(ipip_fini); 1441da177e4SLinus Torvalds MODULE_LICENSE("GPL"); 145