1 /* xfrm4_protocol.c - Generic xfrm protocol multiplexer.
3 * Copyright (C) 2013 secunet Security Networks AG
6 * Steffen Klassert <steffen.klassert@secunet.com>
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
17 #include <linux/init.h>
18 #include <linux/mutex.h>
19 #include <linux/skbuff.h>
22 #include <net/protocol.h>
25 static struct xfrm4_protocol __rcu *esp4_handlers __read_mostly;
26 static struct xfrm4_protocol __rcu *ah4_handlers __read_mostly;
27 static struct xfrm4_protocol __rcu *ipcomp4_handlers __read_mostly;
28 static DEFINE_MUTEX(xfrm4_protocol_mutex);
30 static inline struct xfrm4_protocol __rcu **proto_handlers(u8 protocol)
34 return &esp4_handlers;
38 return &ipcomp4_handlers;
44 #define for_each_protocol_rcu(head, handler) \
45 for (handler = rcu_dereference(head); \
47 handler = rcu_dereference(handler->next)) \
49 int xfrm4_rcv_cb(struct sk_buff *skb, u8 protocol, int err)
52 struct xfrm4_protocol *handler;
53 struct xfrm4_protocol __rcu **head = proto_handlers(protocol);
58 for_each_protocol_rcu(*head, handler)
59 if ((ret = handler->cb_handler(skb, err)) <= 0)
64 EXPORT_SYMBOL(xfrm4_rcv_cb);
66 int xfrm4_rcv_encap(struct sk_buff *skb, int nexthdr, __be32 spi,
70 struct xfrm4_protocol *handler;
71 struct xfrm4_protocol __rcu **head = proto_handlers(nexthdr);
73 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
74 XFRM_SPI_SKB_CB(skb)->family = AF_INET;
75 XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
80 for_each_protocol_rcu(*head, handler)
81 if ((ret = handler->input_handler(skb, nexthdr, spi, encap_type)) != -EINVAL)
85 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
90 EXPORT_SYMBOL(xfrm4_rcv_encap);
92 static int xfrm4_esp_rcv(struct sk_buff *skb)
95 struct xfrm4_protocol *handler;
97 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
99 for_each_protocol_rcu(esp4_handlers, handler)
100 if ((ret = handler->handler(skb)) != -EINVAL)
103 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
109 static int xfrm4_esp_err(struct sk_buff *skb, u32 info)
111 struct xfrm4_protocol *handler;
113 for_each_protocol_rcu(esp4_handlers, handler)
114 if (!handler->err_handler(skb, info))
120 static int xfrm4_ah_rcv(struct sk_buff *skb)
123 struct xfrm4_protocol *handler;
125 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
127 for_each_protocol_rcu(ah4_handlers, handler)
128 if ((ret = handler->handler(skb)) != -EINVAL)
131 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
137 static int xfrm4_ah_err(struct sk_buff *skb, u32 info)
139 struct xfrm4_protocol *handler;
141 for_each_protocol_rcu(ah4_handlers, handler)
142 if (!handler->err_handler(skb, info))
148 static int xfrm4_ipcomp_rcv(struct sk_buff *skb)
151 struct xfrm4_protocol *handler;
153 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
155 for_each_protocol_rcu(ipcomp4_handlers, handler)
156 if ((ret = handler->handler(skb)) != -EINVAL)
159 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
165 static int xfrm4_ipcomp_err(struct sk_buff *skb, u32 info)
167 struct xfrm4_protocol *handler;
169 for_each_protocol_rcu(ipcomp4_handlers, handler)
170 if (!handler->err_handler(skb, info))
176 static const struct net_protocol esp4_protocol = {
177 .handler = xfrm4_esp_rcv,
178 .err_handler = xfrm4_esp_err,
183 static const struct net_protocol ah4_protocol = {
184 .handler = xfrm4_ah_rcv,
185 .err_handler = xfrm4_ah_err,
190 static const struct net_protocol ipcomp4_protocol = {
191 .handler = xfrm4_ipcomp_rcv,
192 .err_handler = xfrm4_ipcomp_err,
197 static const struct xfrm_input_afinfo xfrm4_input_afinfo = {
199 .callback = xfrm4_rcv_cb,
202 static inline const struct net_protocol *netproto(unsigned char protocol)
206 return &esp4_protocol;
208 return &ah4_protocol;
210 return &ipcomp4_protocol;
216 int xfrm4_protocol_register(struct xfrm4_protocol *handler,
217 unsigned char protocol)
219 struct xfrm4_protocol __rcu **pprev;
220 struct xfrm4_protocol *t;
221 bool add_netproto = false;
223 int priority = handler->priority;
225 if (!proto_handlers(protocol) || !netproto(protocol))
228 mutex_lock(&xfrm4_protocol_mutex);
230 if (!rcu_dereference_protected(*proto_handlers(protocol),
231 lockdep_is_held(&xfrm4_protocol_mutex)))
234 for (pprev = proto_handlers(protocol);
235 (t = rcu_dereference_protected(*pprev,
236 lockdep_is_held(&xfrm4_protocol_mutex))) != NULL;
238 if (t->priority < priority)
240 if (t->priority == priority)
244 handler->next = *pprev;
245 rcu_assign_pointer(*pprev, handler);
250 mutex_unlock(&xfrm4_protocol_mutex);
253 if (inet_add_protocol(netproto(protocol), protocol)) {
254 pr_err("%s: can't add protocol\n", __func__);
261 EXPORT_SYMBOL(xfrm4_protocol_register);
263 int xfrm4_protocol_deregister(struct xfrm4_protocol *handler,
264 unsigned char protocol)
266 struct xfrm4_protocol __rcu **pprev;
267 struct xfrm4_protocol *t;
270 if (!proto_handlers(protocol) || !netproto(protocol))
273 mutex_lock(&xfrm4_protocol_mutex);
275 for (pprev = proto_handlers(protocol);
276 (t = rcu_dereference_protected(*pprev,
277 lockdep_is_held(&xfrm4_protocol_mutex))) != NULL;
280 *pprev = handler->next;
286 if (!rcu_dereference_protected(*proto_handlers(protocol),
287 lockdep_is_held(&xfrm4_protocol_mutex))) {
288 if (inet_del_protocol(netproto(protocol), protocol) < 0) {
289 pr_err("%s: can't remove protocol\n", __func__);
294 mutex_unlock(&xfrm4_protocol_mutex);
300 EXPORT_SYMBOL(xfrm4_protocol_deregister);
302 void __init xfrm4_protocol_init(void)
304 xfrm_input_register_afinfo(&xfrm4_input_afinfo);
306 EXPORT_SYMBOL(xfrm4_protocol_init);