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
|
/*
* xfrm_input.c
*
* Changes:
* YOSHIFUJI Hideaki @USAGI
* Split up af-specific portion
*
*/
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <net/dst.h>
#include <net/ip.h>
#include <net/xfrm.h>
static struct kmem_cache *secpath_cachep __read_mostly;
void __secpath_destroy(struct sec_path *sp)
{
int i;
for (i = 0; i < sp->len; i++)
xfrm_state_put(sp->xvec[i]);
kmem_cache_free(secpath_cachep, sp);
}
EXPORT_SYMBOL(__secpath_destroy);
struct sec_path *secpath_dup(struct sec_path *src)
{
struct sec_path *sp;
sp = kmem_cache_alloc(secpath_cachep, GFP_ATOMIC);
if (!sp)
return NULL;
sp->len = 0;
if (src) {
int i;
memcpy(sp, src, sizeof(*sp));
for (i = 0; i < sp->len; i++)
xfrm_state_hold(sp->xvec[i]);
}
atomic_set(&sp->refcnt, 1);
return sp;
}
EXPORT_SYMBOL(secpath_dup);
/* Fetch spi and seq from ipsec header */
int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq)
{
int offset, offset_seq;
int hlen;
switch (nexthdr) {
case IPPROTO_AH:
hlen = sizeof(struct ip_auth_hdr);
offset = offsetof(struct ip_auth_hdr, spi);
offset_seq = offsetof(struct ip_auth_hdr, seq_no);
break;
case IPPROTO_ESP:
hlen = sizeof(struct ip_esp_hdr);
offset = offsetof(struct ip_esp_hdr, spi);
offset_seq = offsetof(struct ip_esp_hdr, seq_no);
break;
case IPPROTO_COMP:
if (!pskb_may_pull(skb, sizeof(struct ip_comp_hdr)))
return -EINVAL;
*spi = htonl(ntohs(*(__be16*)(skb_transport_header(skb) + 2)));
*seq = 0;
return 0;
default:
return 1;
}
if (!pskb_may_pull(skb, hlen))
return -EINVAL;
*spi = *(__be32*)(skb_transport_header(skb) + offset);
*seq = *(__be32*)(skb_transport_header(skb) + offset_seq);
return 0;
}
EXPORT_SYMBOL(xfrm_parse_spi);
int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb)
{
int err;
err = x->outer_mode->afinfo->extract_input(x, skb);
if (err)
return err;
skb->protocol = x->inner_mode->afinfo->eth_proto;
return x->inner_mode->input2(x, skb);
}
EXPORT_SYMBOL(xfrm_prepare_input);
int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
{
int err;
__be32 seq;
struct xfrm_state *x;
int decaps = 0;
unsigned int nhoff = XFRM_SPI_SKB_CB(skb)->nhoff;
unsigned int daddroff = XFRM_SPI_SKB_CB(skb)->daddroff;
/* Allocate new secpath or COW existing one. */
if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) {
struct sec_path *sp;
sp = secpath_dup(skb->sp);
if (!sp)
goto drop;
if (skb->sp)
secpath_put(skb->sp);
skb->sp = sp;
}
seq = 0;
if (!spi && (err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0)
goto drop;
do {
if (skb->sp->len == XFRM_MAX_DEPTH)
goto drop;
x = xfrm_state_lookup((xfrm_address_t *)
(skb_network_header(skb) + daddroff),
spi, nexthdr, AF_INET);
if (x == NULL)
goto drop;
skb->sp->xvec[skb->sp->len++] = x;
spin_lock(&x->lock);
if (unlikely(x->km.state != XFRM_STATE_VALID))
goto drop_unlock;
if ((x->encap ? x->encap->encap_type : 0) != encap_type)
goto drop_unlock;
if (x->props.replay_window && xfrm_replay_check(x, seq))
goto drop_unlock;
if (xfrm_state_check_expire(x))
goto drop_unlock;
nexthdr = x->type->input(x, skb);
if (nexthdr <= 0) {
if (nexthdr == -EBADMSG)
x->stats.integrity_failed++;
goto drop_unlock;
}
skb_network_header(skb)[nhoff] = nexthdr;
/* only the first xfrm gets the encap type */
encap_type = 0;
if (x->props.replay_window)
xfrm_replay_advance(x, seq);
x->curlft.bytes += skb->len;
x->curlft.packets++;
spin_unlock(&x->lock);
if (x->inner_mode->input(x, skb))
goto drop;
if (x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) {
decaps = 1;
break;
}
err = xfrm_parse_spi(skb, nexthdr, &spi, &seq);
if (err < 0)
goto drop;
} while (!err);
nf_reset(skb);
if (decaps) {
dst_release(skb->dst);
skb->dst = NULL;
netif_rx(skb);
return 0;
} else {
return x->inner_mode->afinfo->transport_finish(skb, 0);
}
drop_unlock:
spin_unlock(&x->lock);
drop:
kfree_skb(skb);
return 0;
}
EXPORT_SYMBOL(xfrm_input);
void __init xfrm_input_init(void)
{
secpath_cachep = kmem_cache_create("secpath_cache",
sizeof(struct sec_path),
0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
NULL);
}
|
