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 68 EXPORT_SYMBOL(xfrm6_tunnel_register); 69 70 int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler, unsigned short family) 71 { 72 struct xfrm6_tunnel __rcu **pprev; 73 struct xfrm6_tunnel *t; 74 int ret = -ENOENT; 75 76 mutex_lock(&tunnel6_mutex); 77 78 for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers; 79 (t = rcu_dereference_protected(*pprev, 80 lockdep_is_held(&tunnel6_mutex))) != NULL; 81 pprev = &t->next) { 82 if (t == handler) { 83 *pprev = handler->next; 84 ret = 0; 85 break; 86 } 87 } 88 89 mutex_unlock(&tunnel6_mutex); 90 91 synchronize_net(); 92 93 return ret; 94 } 95 96 EXPORT_SYMBOL(xfrm6_tunnel_deregister); 97 98 #define for_each_tunnel_rcu(head, handler) \ 99 for (handler = rcu_dereference(head); \ 100 handler != NULL; \ 101 handler = rcu_dereference(handler->next)) \ 102 103 static int tunnel6_rcv(struct sk_buff *skb) 104 { 105 struct xfrm6_tunnel *handler; 106 107 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 108 goto drop; 109 110 for_each_tunnel_rcu(tunnel6_handlers, handler) 111 if (!handler->handler(skb)) 112 return 0; 113 114 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0); 115 116 drop: 117 kfree_skb(skb); 118 return 0; 119 } 120 121 static int tunnel46_rcv(struct sk_buff *skb) 122 { 123 struct xfrm6_tunnel *handler; 124 125 if (!pskb_may_pull(skb, sizeof(struct iphdr))) 126 goto drop; 127 128 for_each_tunnel_rcu(tunnel46_handlers, handler) 129 if (!handler->handler(skb)) 130 return 0; 131 132 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0); 133 134 drop: 135 kfree_skb(skb); 136 return 0; 137 } 138 139 static void tunnel6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 140 u8 type, u8 code, int offset, __be32 info) 141 { 142 struct xfrm6_tunnel *handler; 143 144 for_each_tunnel_rcu(tunnel6_handlers, handler) 145 if (!handler->err_handler(skb, opt, type, code, offset, info)) 146 break; 147 } 148 149 static const struct inet6_protocol tunnel6_protocol = { 150 .handler = tunnel6_rcv, 151 .err_handler = tunnel6_err, 152 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 153 }; 154 155 static const struct inet6_protocol tunnel46_protocol = { 156 .handler = tunnel46_rcv, 157 .err_handler = tunnel6_err, 158 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 159 }; 160 161 static int __init tunnel6_init(void) 162 { 163 if (inet6_add_protocol(&tunnel6_protocol, IPPROTO_IPV6)) { 164 pr_err("%s: can't add protocol\n", __func__); 165 return -EAGAIN; 166 } 167 if (inet6_add_protocol(&tunnel46_protocol, IPPROTO_IPIP)) { 168 pr_err("%s: can't add protocol\n", __func__); 169 inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6); 170 return -EAGAIN; 171 } 172 return 0; 173 } 174 175 static void __exit tunnel6_fini(void) 176 { 177 if (inet6_del_protocol(&tunnel46_protocol, IPPROTO_IPIP)) 178 pr_err("%s: can't remove protocol\n", __func__); 179 if (inet6_del_protocol(&tunnel6_protocol, IPPROTO_IPV6)) 180 pr_err("%s: can't remove protocol\n", __func__); 181 } 182 183 module_init(tunnel6_init); 184 module_exit(tunnel6_fini); 185 MODULE_LICENSE("GPL"); 186