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10#include <linux/slab.h>
11#include <linux/module.h>
12#include <linux/netdevice.h>
13#include <net/dst.h>
14#include <net/ip.h>
15#include <net/xfrm.h>
16
17static struct kmem_cache *secpath_cachep __read_mostly;
18
19void __secpath_destroy(struct sec_path *sp)
20{
21 int i;
22 for (i = 0; i < sp->len; i++)
23 xfrm_state_put(sp->xvec[i]);
24 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
32 sp = kmem_cache_alloc(secpath_cachep, GFP_ATOMIC);
33 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++)
42 xfrm_state_hold(sp->xvec[i]);
43 }
44 atomic_set(&sp->refcnt, 1);
45 return sp;
46}
47EXPORT_SYMBOL(secpath_dup);
48
49
50
51int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq)
52{
53 int offset, offset_seq;
54 int hlen;
55
56 switch (nexthdr) {
57 case IPPROTO_AH:
58 hlen = sizeof(struct ip_auth_hdr);
59 offset = offsetof(struct ip_auth_hdr, spi);
60 offset_seq = offsetof(struct ip_auth_hdr, seq_no);
61 break;
62 case IPPROTO_ESP:
63 hlen = sizeof(struct ip_esp_hdr);
64 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;
70 *spi = htonl(ntohs(*(__be16*)(skb_transport_header(skb) + 2)));
71 *seq = 0;
72 return 0;
73 default:
74 return 1;
75 }
76
77 if (!pskb_may_pull(skb, hlen))
78 return -EINVAL;
79
80 *spi = *(__be32*)(skb_transport_header(skb) + offset);
81 *seq = *(__be32*)(skb_transport_header(skb) + offset_seq);
82 return 0;
83}
84
85int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb)
86{
87 struct xfrm_mode *inner_mode = x->inner_mode;
88 int err;
89
90 err = x->outer_mode->afinfo->extract_input(x, skb);
91 if (err)
92 return err;
93
94 if (x->sel.family == AF_UNSPEC) {
95 inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
96 if (inner_mode == NULL)
97 return -EAFNOSUPPORT;
98 }
99
100 skb->protocol = inner_mode->afinfo->eth_proto;
101 return inner_mode->input2(x, skb);
102}
103EXPORT_SYMBOL(xfrm_prepare_input);
104
105int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
106{
107 struct net *net = dev_net(skb->dev);
108 int err;
109 __be32 seq;
110 __be32 seq_hi;
111 struct xfrm_state *x;
112 xfrm_address_t *daddr;
113 struct xfrm_mode *inner_mode;
114 unsigned int family;
115 int decaps = 0;
116 int async = 0;
117
118
119 if (encap_type < 0) {
120 async = 1;
121 x = xfrm_input_state(skb);
122 seq = XFRM_SKB_CB(skb)->seq.input.low;
123 goto resume;
124 }
125
126
127 if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) {
128 struct sec_path *sp;
129
130 sp = secpath_dup(skb->sp);
131 if (!sp) {
132 XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
133 goto drop;
134 }
135 if (skb->sp)
136 secpath_put(skb->sp);
137 skb->sp = sp;
138 }
139
140 daddr = (xfrm_address_t *)(skb_network_header(skb) +
141 XFRM_SPI_SKB_CB(skb)->daddroff);
142 family = XFRM_SPI_SKB_CB(skb)->family;
143
144 seq = 0;
145 if (!spi && (err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0) {
146 XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
147 goto drop;
148 }
149
150 do {
151 if (skb->sp->len == XFRM_MAX_DEPTH) {
152 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
153 goto drop;
154 }
155
156 x = xfrm_state_lookup(net, skb->mark, daddr, spi, nexthdr, family);
157 if (x == NULL) {
158 XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
159 xfrm_audit_state_notfound(skb, family, spi, seq);
160 goto drop;
161 }
162
163 skb->sp->xvec[skb->sp->len++] = x;
164
165 spin_lock(&x->lock);
166 if (unlikely(x->km.state != XFRM_STATE_VALID)) {
167 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEINVALID);
168 goto drop_unlock;
169 }
170
171 if ((x->encap ? x->encap->encap_type : 0) != encap_type) {
172 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
173 goto drop_unlock;
174 }
175
176 if (x->repl->check(x, skb, seq)) {
177 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
178 goto drop_unlock;
179 }
180
181 if (xfrm_state_check_expire(x)) {
182 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEEXPIRED);
183 goto drop_unlock;
184 }
185
186 spin_unlock(&x->lock);
187
188 seq_hi = htonl(xfrm_replay_seqhi(x, seq));
189
190 XFRM_SKB_CB(skb)->seq.input.low = seq;
191 XFRM_SKB_CB(skb)->seq.input.hi = seq_hi;
192
193 skb_dst_force(skb);
194
195 nexthdr = x->type->input(x, skb);
196
197 if (nexthdr == -EINPROGRESS)
198 return 0;
199
200resume:
201 spin_lock(&x->lock);
202 if (nexthdr <= 0) {
203 if (nexthdr == -EBADMSG) {
204 xfrm_audit_state_icvfail(x, skb,
205 x->type->proto);
206 x->stats.integrity_failed++;
207 }
208 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEPROTOERROR);
209 goto drop_unlock;
210 }
211
212
213 encap_type = 0;
214
215 if (async && x->repl->recheck(x, skb, seq)) {
216 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
217 goto drop_unlock;
218 }
219
220 x->repl->advance(x, seq);
221
222 x->curlft.bytes += skb->len;
223 x->curlft.packets++;
224
225 spin_unlock(&x->lock);
226
227 XFRM_MODE_SKB_CB(skb)->protocol = nexthdr;
228
229 inner_mode = x->inner_mode;
230
231 if (x->sel.family == AF_UNSPEC) {
232 inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
233 if (inner_mode == NULL)
234 goto drop;
235 }
236
237 if (inner_mode->input(x, skb)) {
238 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
239 goto drop;
240 }
241
242 if (x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) {
243 decaps = 1;
244 break;
245 }
246
247
248
249
250
251 daddr = &x->id.daddr;
252 family = x->outer_mode->afinfo->family;
253
254 err = xfrm_parse_spi(skb, nexthdr, &spi, &seq);
255 if (err < 0) {
256 XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
257 goto drop;
258 }
259 } while (!err);
260
261 nf_reset(skb);
262
263 if (decaps) {
264 skb_dst_drop(skb);
265 netif_rx(skb);
266 return 0;
267 } else {
268 return x->inner_mode->afinfo->transport_finish(skb, async);
269 }
270
271drop_unlock:
272 spin_unlock(&x->lock);
273drop:
274 kfree_skb(skb);
275 return 0;
276}
277EXPORT_SYMBOL(xfrm_input);
278
279int xfrm_input_resume(struct sk_buff *skb, int nexthdr)
280{
281 return xfrm_input(skb, nexthdr, 0, -1);
282}
283EXPORT_SYMBOL(xfrm_input_resume);
284
285void __init xfrm_input_init(void)
286{
287 secpath_cachep = kmem_cache_create("secpath_cache",
288 sizeof(struct sec_path),
289 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
290 NULL);
291}
292
