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, see <http://www.gnu.org/licenses/>. 16 * 17 * Authors Mitsuru KANDA <mk@linux-ipv6.org> 18 * YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> 19 */ 20 21 #define pr_fmt(fmt) "IPv6: " fmt 22 23 #include <linux/icmpv6.h> 24 #include <linux/init.h> 25 #include <linux/module.h> 26 #include <linux/mutex.h> 27 #include <linux/netdevice.h> 28 #include <linux/skbuff.h> 29 #include <linux/slab.h> 30 #include <net/ipv6.h> 31 #include <net/protocol.h> 32 #include <net/xfrm.h> 33 34 static struct xfrm6_tunnel __rcu *tunnel6_handlers __read_mostly; 35 static struct xfrm6_tunnel __rcu *tunnel46_handlers __read_mostly; 36 static DEFINE_MUTEX(tunnel6_mutex); 37 38 int xfrm6_tunnel_register(struct xfrm6_tunnel *handler, unsigned short family) 39 { 40 struct xfrm6_tunnel __rcu **pprev; 41 struct xfrm6_tunnel *t; 42 int ret = -EEXIST; 43 int priority = handler->priority; 44 45 mutex_lock(&tunnel6_mutex); 46 47 for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers; 48 (t = rcu_dereference_protected(*pprev, 49 lockdep_is_held(&tunnel6_mutex))) != NULL; 50 pprev = &t->next) { 51 if (t->priority > priority) 52 break; 53 if (t->priority == priority) 54 goto err; 55 } 56 57 handler->next = *pprev; 58 rcu_assign_pointer(*pprev, handler); 59 60 ret = 0; 61 62 err: 63 mutex_unlock(&tunnel6_mutex); 64 65 return ret; 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 EXPORT_SYMBOL(xfrm6_tunnel_deregister); 95 96 #define for_each_tunnel_rcu(head, handler) \ 97 for (handler = rcu_dereference(head); \ 98 handler != NULL; \ 99 handler = rcu_dereference(handler->next)) \ 100 101 static int tunnel6_rcv(struct sk_buff *skb) 102 { 103 struct xfrm6_tunnel *handler; 104 105 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 106 goto drop; 107 108 for_each_tunnel_rcu(tunnel6_handlers, handler) 109 if (!handler->handler(skb)) 110 return 0; 111 112 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0); 113 114 drop: 115 kfree_skb(skb); 116 return 0; 117 } 118 119 static int tunnel46_rcv(struct sk_buff *skb) 120 { 121 struct xfrm6_tunnel *handler; 122 123 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 124 goto drop; 125 126 for_each_tunnel_rcu(tunnel46_handlers, handler) 127 if (!handler->handler(skb)) 128 return 0; 129 130 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0); 131 132 drop: 133 kfree_skb(skb); 134 return 0; 135 } 136 137 static void tunnel6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 138 u8 type, u8 code, int offset, __be32 info) 139 { 140 struct xfrm6_tunnel *handler; 141 142 for_each_tunnel_rcu(tunnel6_handlers, handler) 143 if (!handler->err_handler(skb, opt, type, code, offset, info)) 144 break; 145 } 146 147 static const struct inet6_protocol tunnel6_protocol = { 148 .handler = tunnel6_rcv, 149 .err_handler = tunnel6_err, 150 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 151 }; 152 153 static const struct inet6_protocol tunnel46_protocol = { 154 .handler = tunnel46_rcv, 155 .err_handler = tunnel6_err, 156 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 157 }; 158 159 static int __init tunnel6_init(void) 160 { 161 if (inet6_add_protocol(&tunnel6_protocol, IPPROTO_IPV6)) { 162 pr_err("%s: can't add protocol\n", __func__); 163 return -EAGAIN; 164 } 165 if (inet6_add_protocol(&tunnel46_protocol, IPPROTO_IPIP)) { 166 pr_err("%s: can't add protocol\n", __func__); 167 inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6); 168 return -EAGAIN; 169 } 170 return 0; 171 } 172 173 static void __exit tunnel6_fini(void) 174 { 175 if (inet6_del_protocol(&tunnel46_protocol, IPPROTO_IPIP)) 176 pr_err("%s: can't remove protocol\n", __func__); 177 if (inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6)) 178 pr_err("%s: can't remove protocol\n", __func__); 179 } 180 181 module_init(tunnel6_init); 182 module_exit(tunnel6_fini); 183 MODULE_LICENSE("GPL"); 184