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
;
54 for_each_protocol_rcu(*proto_handlers(protocol
), handler
)
55 if ((ret
= handler
->cb_handler(skb
, err
)) <= 0)
60 EXPORT_SYMBOL(xfrm4_rcv_cb
);
62 int xfrm4_rcv_encap(struct sk_buff
*skb
, int nexthdr
, __be32 spi
,
66 struct xfrm4_protocol
*handler
;
68 XFRM_SPI_SKB_CB(skb
)->family
= AF_INET
;
69 XFRM_SPI_SKB_CB(skb
)->daddroff
= offsetof(struct iphdr
, daddr
);
71 for_each_protocol_rcu(*proto_handlers(nexthdr
), handler
)
72 if ((ret
= handler
->input_handler(skb
, nexthdr
, spi
, encap_type
)) != -EINVAL
)
75 icmp_send(skb
, ICMP_DEST_UNREACH
, ICMP_PORT_UNREACH
, 0);
80 EXPORT_SYMBOL(xfrm4_rcv_encap
);
82 static int xfrm4_esp_rcv(struct sk_buff
*skb
)
85 struct xfrm4_protocol
*handler
;
87 for_each_protocol_rcu(esp4_handlers
, handler
)
88 if ((ret
= handler
->handler(skb
)) != -EINVAL
)
91 icmp_send(skb
, ICMP_DEST_UNREACH
, ICMP_PORT_UNREACH
, 0);
97 static void xfrm4_esp_err(struct sk_buff
*skb
, u32 info
)
99 struct xfrm4_protocol
*handler
;
101 for_each_protocol_rcu(esp4_handlers
, handler
)
102 if (!handler
->err_handler(skb
, info
))
106 static int xfrm4_ah_rcv(struct sk_buff
*skb
)
109 struct xfrm4_protocol
*handler
;
111 for_each_protocol_rcu(ah4_handlers
, handler
)
112 if ((ret
= handler
->handler(skb
)) != -EINVAL
)
115 icmp_send(skb
, ICMP_DEST_UNREACH
, ICMP_PORT_UNREACH
, 0);
121 static void xfrm4_ah_err(struct sk_buff
*skb
, u32 info
)
123 struct xfrm4_protocol
*handler
;
125 for_each_protocol_rcu(ah4_handlers
, handler
)
126 if (!handler
->err_handler(skb
, info
))
130 static int xfrm4_ipcomp_rcv(struct sk_buff
*skb
)
133 struct xfrm4_protocol
*handler
;
135 for_each_protocol_rcu(ipcomp4_handlers
, handler
)
136 if ((ret
= handler
->handler(skb
)) != -EINVAL
)
139 icmp_send(skb
, ICMP_DEST_UNREACH
, ICMP_PORT_UNREACH
, 0);
145 static void xfrm4_ipcomp_err(struct sk_buff
*skb
, u32 info
)
147 struct xfrm4_protocol
*handler
;
149 for_each_protocol_rcu(ipcomp4_handlers
, handler
)
150 if (!handler
->err_handler(skb
, info
))
154 static const struct net_protocol esp4_protocol
= {
155 .handler
= xfrm4_esp_rcv
,
156 .err_handler
= xfrm4_esp_err
,
161 static const struct net_protocol ah4_protocol
= {
162 .handler
= xfrm4_ah_rcv
,
163 .err_handler
= xfrm4_ah_err
,
168 static const struct net_protocol ipcomp4_protocol
= {
169 .handler
= xfrm4_ipcomp_rcv
,
170 .err_handler
= xfrm4_ipcomp_err
,
175 static inline const struct net_protocol
*netproto(unsigned char protocol
)
179 return &esp4_protocol
;
181 return &ah4_protocol
;
183 return &ipcomp4_protocol
;
189 int xfrm4_protocol_register(struct xfrm4_protocol
*handler
,
190 unsigned char protocol
)
192 struct xfrm4_protocol __rcu
**pprev
;
193 struct xfrm4_protocol
*t
;
194 bool add_netproto
= false;
197 int priority
= handler
->priority
;
199 mutex_lock(&xfrm4_protocol_mutex
);
201 if (!rcu_dereference_protected(*proto_handlers(protocol
),
202 lockdep_is_held(&xfrm4_protocol_mutex
)))
205 for (pprev
= proto_handlers(protocol
);
206 (t
= rcu_dereference_protected(*pprev
,
207 lockdep_is_held(&xfrm4_protocol_mutex
))) != NULL
;
209 if (t
->priority
< priority
)
211 if (t
->priority
== priority
)
215 handler
->next
= *pprev
;
216 rcu_assign_pointer(*pprev
, handler
);
221 mutex_unlock(&xfrm4_protocol_mutex
);
224 if (inet_add_protocol(netproto(protocol
), protocol
)) {
225 pr_err("%s: can't add protocol\n", __func__
);
232 EXPORT_SYMBOL(xfrm4_protocol_register
);
234 int xfrm4_protocol_deregister(struct xfrm4_protocol
*handler
,
235 unsigned char protocol
)
237 struct xfrm4_protocol __rcu
**pprev
;
238 struct xfrm4_protocol
*t
;
241 mutex_lock(&xfrm4_protocol_mutex
);
243 for (pprev
= proto_handlers(protocol
);
244 (t
= rcu_dereference_protected(*pprev
,
245 lockdep_is_held(&xfrm4_protocol_mutex
))) != NULL
;
248 *pprev
= handler
->next
;
254 if (!rcu_dereference_protected(*proto_handlers(protocol
),
255 lockdep_is_held(&xfrm4_protocol_mutex
))) {
256 if (inet_del_protocol(netproto(protocol
), protocol
) < 0) {
257 pr_err("%s: can't remove protocol\n", __func__
);
262 mutex_unlock(&xfrm4_protocol_mutex
);
268 EXPORT_SYMBOL(xfrm4_protocol_deregister
);