1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
|
/* xfrm6_protocol.c - Generic xfrm protocol multiplexer for ipv6.
*
* Copyright (C) 2013 secunet Security Networks AG
*
* Author:
* Steffen Klassert <steffen.klassert@secunet.com>
*
* Based on:
* net/ipv4/xfrm4_protocol.c
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/skbuff.h>
#include <linux/icmpv6.h>
#include <net/ipv6.h>
#include <net/protocol.h>
#include <net/xfrm.h>
static struct xfrm6_protocol __rcu *esp6_handlers __read_mostly;
static struct xfrm6_protocol __rcu *ah6_handlers __read_mostly;
static struct xfrm6_protocol __rcu *ipcomp6_handlers __read_mostly;
static DEFINE_MUTEX(xfrm6_protocol_mutex);
static inline struct xfrm6_protocol __rcu **proto_handlers(u8 protocol)
{
switch (protocol) {
case IPPROTO_ESP:
return &esp6_handlers;
case IPPROTO_AH:
return &ah6_handlers;
case IPPROTO_COMP:
return &ipcomp6_handlers;
}
return NULL;
}
#define for_each_protocol_rcu(head, handler) \
for (handler = rcu_dereference(head); \
handler != NULL; \
handler = rcu_dereference(handler->next)) \
int xfrm6_rcv_cb(struct sk_buff *skb, u8 protocol, int err)
{
int ret;
struct xfrm6_protocol *handler;
struct xfrm6_protocol __rcu **head = proto_handlers(protocol);
if (!head)
return 0;
for_each_protocol_rcu(*proto_handlers(protocol), handler)
if ((ret = handler->cb_handler(skb, err)) <= 0)
return ret;
return 0;
}
EXPORT_SYMBOL(xfrm6_rcv_cb);
static int xfrm6_esp_rcv(struct sk_buff *skb)
{
int ret;
struct xfrm6_protocol *handler;
XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;
for_each_protocol_rcu(esp6_handlers, handler)
if ((ret = handler->handler(skb)) != -EINVAL)
return ret;
icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
kfree_skb(skb);
return 0;
}
static void xfrm6_esp_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
u8 type, u8 code, int offset, __be32 info)
{
struct xfrm6_protocol *handler;
for_each_protocol_rcu(esp6_handlers, handler)
if (!handler->err_handler(skb, opt, type, code, offset, info))
break;
}
static int xfrm6_ah_rcv(struct sk_buff *skb)
{
int ret;
struct xfrm6_protocol *handler;
XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;
for_each_protocol_rcu(ah6_handlers, handler)
if ((ret = handler->handler(skb)) != -EINVAL)
return ret;
icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
kfree_skb(skb);
return 0;
}
static void xfrm6_ah_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
u8 type, u8 code, int offset, __be32 info)
{
struct xfrm6_protocol *handler;
for_each_protocol_rcu(ah6_handlers, handler)
if (!handler->err_handler(skb, opt, type, code, offset, info))
break;
}
static int xfrm6_ipcomp_rcv(struct sk_buff *skb)
{
int ret;
struct xfrm6_protocol *handler;
XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;
for_each_protocol_rcu(ipcomp6_handlers, handler)
if ((ret = handler->handler(skb)) != -EINVAL)
return ret;
icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
kfree_skb(skb);
return 0;
}
static void xfrm6_ipcomp_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
u8 type, u8 code, int offset, __be32 info)
{
struct xfrm6_protocol *handler;
for_each_protocol_rcu(ipcomp6_handlers, handler)
if (!handler->err_handler(skb, opt, type, code, offset, info))
break;
}
static const struct inet6_protocol esp6_protocol = {
.handler = xfrm6_esp_rcv,
.err_handler = xfrm6_esp_err,
.flags = INET6_PROTO_NOPOLICY,
};
static const struct inet6_protocol ah6_protocol = {
.handler = xfrm6_ah_rcv,
.err_handler = xfrm6_ah_err,
.flags = INET6_PROTO_NOPOLICY,
};
static const struct inet6_protocol ipcomp6_protocol = {
.handler = xfrm6_ipcomp_rcv,
.err_handler = xfrm6_ipcomp_err,
.flags = INET6_PROTO_NOPOLICY,
};
static const struct xfrm_input_afinfo xfrm6_input_afinfo = {
.family = AF_INET6,
.callback = xfrm6_rcv_cb,
};
static inline const struct inet6_protocol *netproto(unsigned char protocol)
{
switch (protocol) {
case IPPROTO_ESP:
return &esp6_protocol;
case IPPROTO_AH:
return &ah6_protocol;
case IPPROTO_COMP:
return &ipcomp6_protocol;
}
return NULL;
}
int xfrm6_protocol_register(struct xfrm6_protocol *handler,
unsigned char protocol)
{
struct xfrm6_protocol __rcu **pprev;
struct xfrm6_protocol *t;
bool add_netproto = false;
int ret = -EEXIST;
int priority = handler->priority;
if (!proto_handlers(protocol) || !netproto(protocol))
return -EINVAL;
mutex_lock(&xfrm6_protocol_mutex);
if (!rcu_dereference_protected(*proto_handlers(protocol),
lockdep_is_held(&xfrm6_protocol_mutex)))
add_netproto = true;
for (pprev = proto_handlers(protocol);
(t = rcu_dereference_protected(*pprev,
lockdep_is_held(&xfrm6_protocol_mutex))) != NULL;
pprev = &t->next) {
if (t->priority < priority)
break;
if (t->priority == priority)
goto err;
}
handler->next = *pprev;
rcu_assign_pointer(*pprev, handler);
ret = 0;
err:
mutex_unlock(&xfrm6_protocol_mutex);
if (add_netproto) {
if (inet6_add_protocol(netproto(protocol), protocol)) {
pr_err("%s: can't add protocol\n", __func__);
ret = -EAGAIN;
}
}
return ret;
}
EXPORT_SYMBOL(xfrm6_protocol_register);
int xfrm6_protocol_deregister(struct xfrm6_protocol *handler,
unsigned char protocol)
{
struct xfrm6_protocol __rcu **pprev;
struct xfrm6_protocol *t;
int ret = -ENOENT;
if (!proto_handlers(protocol) || !netproto(protocol))
return -EINVAL;
mutex_lock(&xfrm6_protocol_mutex);
for (pprev = proto_handlers(protocol);
(t = rcu_dereference_protected(*pprev,
lockdep_is_held(&xfrm6_protocol_mutex))) != NULL;
pprev = &t->next) {
if (t == handler) {
*pprev = handler->next;
ret = 0;
break;
}
}
if (!rcu_dereference_protected(*proto_handlers(protocol),
lockdep_is_held(&xfrm6_protocol_mutex))) {
if (inet6_del_protocol(netproto(protocol), protocol) < 0) {
pr_err("%s: can't remove protocol\n", __func__);
ret = -EAGAIN;
}
}
mutex_unlock(&xfrm6_protocol_mutex);
synchronize_net();
return ret;
}
EXPORT_SYMBOL(xfrm6_protocol_deregister);
int __init xfrm6_protocol_init(void)
{
return xfrm_input_register_afinfo(&xfrm6_input_afinfo);
}
void xfrm6_protocol_fini(void)
{
xfrm_input_unregister_afinfo(&xfrm6_input_afinfo);
}
|
