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 <linux/slab.h> 29 #include <net/ipv6.h> 30 #include <net/protocol.h> 31 #include <net/xfrm.h> 32 33 static struct xfrm6_tunnel __rcu *tunnel6_handlers __read_mostly; 34 static struct xfrm6_tunnel __rcu *tunnel46_handlers __read_mostly; 35 static DEFINE_MUTEX(tunnel6_mutex); 36 37 int xfrm6_tunnel_register(struct xfrm6_tunnel *handler, unsigned short family) 38 { 39 struct xfrm6_tunnel __rcu **pprev; 40 struct xfrm6_tunnel *t; 41 int ret = -EEXIST; 42 int priority = handler->priority; 43 44 mutex_lock(&tunnel6_mutex); 45 46 for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers; 47 (t = rcu_dereference_protected(*pprev, 48 lockdep_is_held(&tunnel6_mutex))) != NULL; 49 pprev = &t->next) { 50 if (t->priority > priority) 51 break; 52 if (t->priority == priority) 53 goto err; 54 } 55 56 handler->next = *pprev; 57 rcu_assign_pointer(*pprev, handler); 58 59 ret = 0; 60 61 err: 62 mutex_unlock(&tunnel6_mutex); 63 64 return ret; 65 } 66 67 EXPORT_SYMBOL(xfrm6_tunnel_register); 68 69 int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler, unsigned short family) 70 { 71 struct xfrm6_tunnel __rcu **pprev; 72 struct xfrm6_tunnel *t; 73 int ret = -ENOENT; 74 75 mutex_lock(&tunnel6_mutex); 76 77 for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers; 78 (t = rcu_dereference_protected(*pprev, 79 lockdep_is_held(&tunnel6_mutex))) != NULL; 80 pprev = &t->next) { 81 if (t == handler) { 82 *pprev = handler->next; 83 ret = 0; 84 break; 85 } 86 } 87 88 mutex_unlock(&tunnel6_mutex); 89 90 synchronize_net(); 91 92 return ret; 93 } 94 95 EXPORT_SYMBOL(xfrm6_tunnel_deregister); 96 97 #define for_each_tunnel_rcu(head, handler) \ 98 for (handler = rcu_dereference(head); \ 99 handler != NULL; \ 100 handler = rcu_dereference(handler->next)) \ 101 102 static int tunnel6_rcv(struct sk_buff *skb) 103 { 104 struct xfrm6_tunnel *handler; 105 106 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 107 goto drop; 108 109 for_each_tunnel_rcu(tunnel6_handlers, handler) 110 if (!handler->handler(skb)) 111 return 0; 112 113 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0); 114 115 drop: 116 kfree_skb(skb); 117 return 0; 118 } 119 120 static int tunnel46_rcv(struct sk_buff *skb) 121 { 122 struct xfrm6_tunnel *handler; 123 124 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 125 goto drop; 126 127 for_each_tunnel_rcu(tunnel46_handlers, handler) 128 if (!handler->handler(skb)) 129 return 0; 130 131 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0); 132 133 drop: 134 kfree_skb(skb); 135 return 0; 136 } 137 138 static void tunnel6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 139 u8 type, u8 code, int offset, __be32 info) 140 { 141 struct xfrm6_tunnel *handler; 142 143 for_each_tunnel_rcu(tunnel6_handlers, handler) 144 if (!handler->err_handler(skb, opt, type, code, offset, info)) 145 break; 146 } 147 148 static const struct inet6_protocol tunnel6_protocol = { 149 .handler = tunnel6_rcv, 150 .err_handler = tunnel6_err, 151 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 152 }; 153 154 static const struct inet6_protocol tunnel46_protocol = { 155 .handler = tunnel46_rcv, 156 .err_handler = tunnel6_err, 157 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 158 }; 159 160 static int __init tunnel6_init(void) 161 { 162 if (inet6_add_protocol(&tunnel6_protocol, IPPROTO_IPV6)) { 163 printk(KERN_ERR "tunnel6 init(): can't add protocol\n"); 164 return -EAGAIN; 165 } 166 if (inet6_add_protocol(&tunnel46_protocol, IPPROTO_IPIP)) { 167 printk(KERN_ERR "tunnel6 init(): can't add protocol\n"); 168 inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6); 169 return -EAGAIN; 170 } 171 return 0; 172 } 173 174 static void __exit tunnel6_fini(void) 175 { 176 if (inet6_del_protocol(&tunnel46_protocol, IPPROTO_IPIP)) 177 printk(KERN_ERR "tunnel6 close: can't remove protocol\n"); 178 if (inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6)) 179 printk(KERN_ERR "tunnel6 close: can't remove protocol\n"); 180 } 181 182 module_init(tunnel6_init); 183 module_exit(tunnel6_fini); 184 MODULE_LICENSE("GPL"); 185