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 struct xfrm6_tunnel *tunnel46_handlers; 34 static DEFINE_MUTEX(tunnel6_mutex); 35 36 int xfrm6_tunnel_register(struct xfrm6_tunnel *handler, unsigned short family) 37 { 38 struct xfrm6_tunnel **pprev; 39 int ret = -EEXIST; 40 int priority = handler->priority; 41 42 mutex_lock(&tunnel6_mutex); 43 44 for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers; 45 *pprev; pprev = &(*pprev)->next) { 46 if ((*pprev)->priority > priority) 47 break; 48 if ((*pprev)->priority == priority) 49 goto err; 50 } 51 52 handler->next = *pprev; 53 *pprev = handler; 54 55 ret = 0; 56 57 err: 58 mutex_unlock(&tunnel6_mutex); 59 60 return ret; 61 } 62 63 EXPORT_SYMBOL(xfrm6_tunnel_register); 64 65 int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler, unsigned short family) 66 { 67 struct xfrm6_tunnel **pprev; 68 int ret = -ENOENT; 69 70 mutex_lock(&tunnel6_mutex); 71 72 for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers; 73 *pprev; pprev = &(*pprev)->next) { 74 if (*pprev == handler) { 75 *pprev = handler->next; 76 ret = 0; 77 break; 78 } 79 } 80 81 mutex_unlock(&tunnel6_mutex); 82 83 synchronize_net(); 84 85 return ret; 86 } 87 88 EXPORT_SYMBOL(xfrm6_tunnel_deregister); 89 90 static int tunnel6_rcv(struct sk_buff *skb) 91 { 92 struct xfrm6_tunnel *handler; 93 94 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 95 goto drop; 96 97 for (handler = tunnel6_handlers; handler; handler = handler->next) 98 if (!handler->handler(skb)) 99 return 0; 100 101 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0, skb->dev); 102 103 drop: 104 kfree_skb(skb); 105 return 0; 106 } 107 108 static int tunnel46_rcv(struct sk_buff *skb) 109 { 110 struct xfrm6_tunnel *handler; 111 112 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 113 goto drop; 114 115 for (handler = tunnel46_handlers; handler; handler = handler->next) 116 if (!handler->handler(skb)) 117 return 0; 118 119 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0, skb->dev); 120 121 drop: 122 kfree_skb(skb); 123 return 0; 124 } 125 126 static void tunnel6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 127 u8 type, u8 code, int offset, __be32 info) 128 { 129 struct xfrm6_tunnel *handler; 130 131 for (handler = tunnel6_handlers; handler; handler = handler->next) 132 if (!handler->err_handler(skb, opt, type, code, offset, info)) 133 break; 134 } 135 136 static const struct inet6_protocol tunnel6_protocol = { 137 .handler = tunnel6_rcv, 138 .err_handler = tunnel6_err, 139 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 140 }; 141 142 static const struct inet6_protocol tunnel46_protocol = { 143 .handler = tunnel46_rcv, 144 .err_handler = tunnel6_err, 145 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 146 }; 147 148 static int __init tunnel6_init(void) 149 { 150 if (inet6_add_protocol(&tunnel6_protocol, IPPROTO_IPV6)) { 151 printk(KERN_ERR "tunnel6 init(): can't add protocol\n"); 152 return -EAGAIN; 153 } 154 if (inet6_add_protocol(&tunnel46_protocol, IPPROTO_IPIP)) { 155 printk(KERN_ERR "tunnel6 init(): can't add protocol\n"); 156 inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6); 157 return -EAGAIN; 158 } 159 return 0; 160 } 161 162 static void __exit tunnel6_fini(void) 163 { 164 if (inet6_del_protocol(&tunnel46_protocol, IPPROTO_IPIP)) 165 printk(KERN_ERR "tunnel6 close: can't remove protocol\n"); 166 if (inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6)) 167 printk(KERN_ERR "tunnel6 close: can't remove protocol\n"); 168 } 169 170 module_init(tunnel6_init); 171 module_exit(tunnel6_fini); 172 MODULE_LICENSE("GPL"); 173