blob: 96f42c1d2e8eb56542c3fc743179bf90f2be8d2a [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * xfrm_input.c
3 *
4 * Changes:
5 * YOSHIFUJI Hideaki @USAGI
6 * Split up af-specific portion
YOSHIFUJI Hideakia716c112007-02-09 23:25:29 +09007 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 */
9
10#include <linux/slab.h>
11#include <linux/module.h>
Herbert Xu716062f2007-11-13 21:44:23 -080012#include <linux/netdevice.h>
13#include <net/dst.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <net/ip.h>
15#include <net/xfrm.h>
16
Christoph Lametere18b8902006-12-06 20:33:20 -080017static struct kmem_cache *secpath_cachep __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070018
19void __secpath_destroy(struct sec_path *sp)
20{
21 int i;
22 for (i = 0; i < sp->len; i++)
Herbert Xudbe5b4a2006-04-01 00:54:16 -080023 xfrm_state_put(sp->xvec[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -070024 kmem_cache_free(secpath_cachep, sp);
25}
26EXPORT_SYMBOL(__secpath_destroy);
27
28struct sec_path *secpath_dup(struct sec_path *src)
29{
30 struct sec_path *sp;
31
Christoph Lameter54e6ecb2006-12-06 20:33:16 -080032 sp = kmem_cache_alloc(secpath_cachep, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -070033 if (!sp)
34 return NULL;
35
36 sp->len = 0;
37 if (src) {
38 int i;
39
40 memcpy(sp, src, sizeof(*sp));
41 for (i = 0; i < sp->len; i++)
Herbert Xudbe5b4a2006-04-01 00:54:16 -080042 xfrm_state_hold(sp->xvec[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 }
44 atomic_set(&sp->refcnt, 1);
45 return sp;
46}
47EXPORT_SYMBOL(secpath_dup);
48
49/* Fetch spi and seq from ipsec header */
50
Al Viro6067b2b2006-09-27 18:47:59 -070051int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq)
Linus Torvalds1da177e2005-04-16 15:20:36 -070052{
53 int offset, offset_seq;
Herbert Xu44072502007-10-17 21:30:34 -070054 int hlen;
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
56 switch (nexthdr) {
57 case IPPROTO_AH:
Herbert Xu44072502007-10-17 21:30:34 -070058 hlen = sizeof(struct ip_auth_hdr);
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 offset = offsetof(struct ip_auth_hdr, spi);
60 offset_seq = offsetof(struct ip_auth_hdr, seq_no);
61 break;
62 case IPPROTO_ESP:
Herbert Xu44072502007-10-17 21:30:34 -070063 hlen = sizeof(struct ip_esp_hdr);
Linus Torvalds1da177e2005-04-16 15:20:36 -070064 offset = offsetof(struct ip_esp_hdr, spi);
65 offset_seq = offsetof(struct ip_esp_hdr, seq_no);
66 break;
67 case IPPROTO_COMP:
68 if (!pskb_may_pull(skb, sizeof(struct ip_comp_hdr)))
69 return -EINVAL;
Arnaldo Carvalho de Melo9c702202007-04-25 18:04:18 -070070 *spi = htonl(ntohs(*(__be16*)(skb_transport_header(skb) + 2)));
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 *seq = 0;
72 return 0;
73 default:
74 return 1;
75 }
76
Herbert Xu44072502007-10-17 21:30:34 -070077 if (!pskb_may_pull(skb, hlen))
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 return -EINVAL;
79
Arnaldo Carvalho de Melo9c702202007-04-25 18:04:18 -070080 *spi = *(__be32*)(skb_transport_header(skb) + offset);
81 *seq = *(__be32*)(skb_transport_header(skb) + offset_seq);
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 return 0;
83}
84EXPORT_SYMBOL(xfrm_parse_spi);
85
Herbert Xu227620e2007-11-13 21:41:28 -080086int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb)
87{
88 int err;
89
90 err = x->outer_mode->afinfo->extract_input(x, skb);
91 if (err)
92 return err;
93
94 skb->protocol = x->inner_mode->afinfo->eth_proto;
95 return x->inner_mode->input2(x, skb);
96}
97EXPORT_SYMBOL(xfrm_prepare_input);
98
Herbert Xu716062f2007-11-13 21:44:23 -080099int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
100{
101 int err;
102 __be32 seq;
Herbert Xu716062f2007-11-13 21:44:23 -0800103 struct xfrm_state *x;
Herbert Xu1bf06cd2007-11-19 18:50:17 -0800104 xfrm_address_t *daddr;
Herbert Xu716062f2007-11-13 21:44:23 -0800105 int decaps = 0;
Herbert Xu1bf06cd2007-11-19 18:50:17 -0800106 int async = 0;
107
108 /* A negative encap_type indicates async resumption. */
109 if (encap_type < 0) {
110 async = 1;
111 x = skb->sp->xvec[skb->sp->len - 1];
112 seq = XFRM_SKB_CB(skb)->seq;
113 goto resume;
114 }
Herbert Xu716062f2007-11-13 21:44:23 -0800115
Herbert Xub2aa5e92007-11-13 21:44:55 -0800116 /* Allocate new secpath or COW existing one. */
117 if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) {
118 struct sec_path *sp;
119
120 sp = secpath_dup(skb->sp);
121 if (!sp)
122 goto drop;
123 if (skb->sp)
124 secpath_put(skb->sp);
125 skb->sp = sp;
126 }
127
Herbert Xu1bf06cd2007-11-19 18:50:17 -0800128 daddr = (xfrm_address_t *)(skb_network_header(skb) +
129 XFRM_SPI_SKB_CB(skb)->daddroff);
130
Herbert Xu716062f2007-11-13 21:44:23 -0800131 seq = 0;
132 if (!spi && (err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0)
133 goto drop;
134
135 do {
Herbert Xub2aa5e92007-11-13 21:44:55 -0800136 if (skb->sp->len == XFRM_MAX_DEPTH)
Herbert Xu716062f2007-11-13 21:44:23 -0800137 goto drop;
138
Herbert Xu1bf06cd2007-11-19 18:50:17 -0800139 x = xfrm_state_lookup(daddr, spi, nexthdr, AF_INET);
Herbert Xu716062f2007-11-13 21:44:23 -0800140 if (x == NULL)
141 goto drop;
142
Herbert Xub2aa5e92007-11-13 21:44:55 -0800143 skb->sp->xvec[skb->sp->len++] = x;
144
Herbert Xu716062f2007-11-13 21:44:23 -0800145 spin_lock(&x->lock);
146 if (unlikely(x->km.state != XFRM_STATE_VALID))
147 goto drop_unlock;
148
149 if ((x->encap ? x->encap->encap_type : 0) != encap_type)
150 goto drop_unlock;
151
152 if (x->props.replay_window && xfrm_replay_check(x, seq))
153 goto drop_unlock;
154
155 if (xfrm_state_check_expire(x))
156 goto drop_unlock;
157
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800158 spin_unlock(&x->lock);
159
Herbert Xu1bf06cd2007-11-19 18:50:17 -0800160 XFRM_SKB_CB(skb)->seq = seq;
161
Herbert Xu716062f2007-11-13 21:44:23 -0800162 nexthdr = x->type->input(x, skb);
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800163
Herbert Xu1bf06cd2007-11-19 18:50:17 -0800164 if (nexthdr == -EINPROGRESS)
165 return 0;
166
167resume:
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800168 spin_lock(&x->lock);
Herbert Xu668dc8a2007-12-16 15:55:02 -0800169 if (nexthdr <= 0) {
170 if (nexthdr == -EBADMSG)
171 x->stats.integrity_failed++;
Herbert Xu716062f2007-11-13 21:44:23 -0800172 goto drop_unlock;
Herbert Xu668dc8a2007-12-16 15:55:02 -0800173 }
Herbert Xu716062f2007-11-13 21:44:23 -0800174
Herbert Xu716062f2007-11-13 21:44:23 -0800175 /* only the first xfrm gets the encap type */
176 encap_type = 0;
177
178 if (x->props.replay_window)
179 xfrm_replay_advance(x, seq);
180
181 x->curlft.bytes += skb->len;
182 x->curlft.packets++;
183
184 spin_unlock(&x->lock);
185
Herbert Xu60d5fcf2007-11-19 18:47:58 -0800186 XFRM_MODE_SKB_CB(skb)->protocol = nexthdr;
187
Herbert Xu716062f2007-11-13 21:44:23 -0800188 if (x->inner_mode->input(x, skb))
189 goto drop;
190
191 if (x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) {
192 decaps = 1;
193 break;
194 }
195
Herbert Xu1bf06cd2007-11-19 18:50:17 -0800196 /*
197 * We need the inner address. However, we only get here for
198 * transport mode so the outer address is identical.
199 */
200 daddr = &x->id.daddr;
201
Herbert Xu716062f2007-11-13 21:44:23 -0800202 err = xfrm_parse_spi(skb, nexthdr, &spi, &seq);
203 if (err < 0)
204 goto drop;
205 } while (!err);
206
Herbert Xu716062f2007-11-13 21:44:23 -0800207 nf_reset(skb);
208
209 if (decaps) {
210 dst_release(skb->dst);
211 skb->dst = NULL;
212 netif_rx(skb);
213 return 0;
214 } else {
Herbert Xu1bf06cd2007-11-19 18:50:17 -0800215 return x->inner_mode->afinfo->transport_finish(skb, async);
Herbert Xu716062f2007-11-13 21:44:23 -0800216 }
217
218drop_unlock:
219 spin_unlock(&x->lock);
Herbert Xu716062f2007-11-13 21:44:23 -0800220drop:
Herbert Xu716062f2007-11-13 21:44:23 -0800221 kfree_skb(skb);
222 return 0;
223}
224EXPORT_SYMBOL(xfrm_input);
225
Herbert Xu1bf06cd2007-11-19 18:50:17 -0800226int xfrm_input_resume(struct sk_buff *skb, int nexthdr)
227{
228 return xfrm_input(skb, nexthdr, 0, -1);
229}
230EXPORT_SYMBOL(xfrm_input_resume);
231
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232void __init xfrm_input_init(void)
233{
234 secpath_cachep = kmem_cache_create("secpath_cache",
235 sizeof(struct sec_path),
Alexey Dobriyane5d679f332006-08-26 19:25:52 -0700236 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
Paul Mundt20c2df82007-07-20 10:11:58 +0900237 NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238}