1 /* 2 * Copyright (C)2003,2004 USAGI/WIDE Project 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 17 * 18 * Authors Mitsuru KANDA <mk@linux-ipv6.org> 19 * YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> 20 */ 21 22 #include <linux/icmpv6.h> 23 #include <linux/init.h> 24 #include <linux/module.h> 25 #include <linux/mutex.h> 26 #include <linux/netdevice.h> 27 #include <linux/skbuff.h> 28 #include <net/ipv6.h> 29 #include <net/protocol.h> 30 #include <net/xfrm.h> 31 32 static struct xfrm6_tunnel *tunnel6_handlers; 33 static DEFINE_MUTEX(tunnel6_mutex); 34 35 int xfrm6_tunnel_register(struct xfrm6_tunnel *handler) 36 { 37 struct xfrm6_tunnel **pprev; 38 int ret = -EEXIST; 39 int priority = handler->priority; 40 41 mutex_lock(&tunnel6_mutex); 42 43 for (pprev = &tunnel6_handlers; *pprev; pprev = &(*pprev)->next) { 44 if ((*pprev)->priority > priority) 45 break; 46 if ((*pprev)->priority == priority) 47 goto err; 48 } 49 50 handler->next = *pprev; 51 *pprev = handler; 52 53 ret = 0; 54 55 err: 56 mutex_unlock(&tunnel6_mutex); 57 58 return ret; 59 } 60 61 EXPORT_SYMBOL(xfrm6_tunnel_register); 62 63 int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler) 64 { 65 struct xfrm6_tunnel **pprev; 66 int ret = -ENOENT; 67 68 mutex_lock(&tunnel6_mutex); 69 70 for (pprev = &tunnel6_handlers; *pprev; pprev = &(*pprev)->next) { 71 if (*pprev == handler) { 72 *pprev = handler->next; 73 ret = 0; 74 break; 75 } 76 } 77 78 mutex_unlock(&tunnel6_mutex); 79 80 synchronize_net(); 81 82 return ret; 83 } 84 85 EXPORT_SYMBOL(xfrm6_tunnel_deregister); 86 87 static int tunnel6_rcv(struct sk_buff **pskb) 88 { 89 struct sk_buff *skb = *pskb; 90 struct xfrm6_tunnel *handler; 91 92 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 93 goto drop; 94 95 for (handler = tunnel6_handlers; handler; handler = handler->next) 96 if (!handler->handler(skb)) 97 return 0; 98 99 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0, skb->dev); 100 101 drop: 102 kfree_skb(skb); 103 return 0; 104 } 105 106 static void tunnel6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 107 int type, int code, int offset, __u32 info) 108 { 109 struct xfrm6_tunnel *handler; 110 111 for (handler = tunnel6_handlers; handler; handler = handler->next) 112 if (!handler->err_handler(skb, opt, type, code, offset, info)) 113 break; 114 } 115 116 static struct inet6_protocol tunnel6_protocol = { 117 .handler = tunnel6_rcv, 118 .err_handler = tunnel6_err, 119 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 120 }; 121 122 static int __init tunnel6_init(void) 123 { 124 if (inet6_add_protocol(&tunnel6_protocol, IPPROTO_IPV6)) { 125 printk(KERN_ERR "tunnel6 init(): can't add protocol\n"); 126 return -EAGAIN; 127 } 128 return 0; 129 } 130 131 static void __exit tunnel6_fini(void) 132 { 133 if (inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6)) 134 printk(KERN_ERR "tunnel6 close: can't remove protocol\n"); 135 } 136 137 module_init(tunnel6_init); 138 module_exit(tunnel6_fini); 139 MODULE_LICENSE("GPL"); 140