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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#include <net/ip_tunnels.h>
17#include <net/ip6_tunnel.h>
18
19static struct kmem_cache *secpath_cachep __read_mostly;
20
21static DEFINE_SPINLOCK(xfrm_input_afinfo_lock);
22static struct xfrm_input_afinfo __rcu *xfrm_input_afinfo[NPROTO];
23
24int xfrm_input_register_afinfo(struct xfrm_input_afinfo *afinfo)
25{
26 int err = 0;
27
28 if (unlikely(afinfo == NULL))
29 return -EINVAL;
30 if (unlikely(afinfo->family >= NPROTO))
31 return -EAFNOSUPPORT;
32 spin_lock_bh(&xfrm_input_afinfo_lock);
33 if (unlikely(xfrm_input_afinfo[afinfo->family] != NULL))
34 err = -EEXIST;
35 else
36 rcu_assign_pointer(xfrm_input_afinfo[afinfo->family], afinfo);
37 spin_unlock_bh(&xfrm_input_afinfo_lock);
38 return err;
39}
40EXPORT_SYMBOL(xfrm_input_register_afinfo);
41
42int xfrm_input_unregister_afinfo(struct xfrm_input_afinfo *afinfo)
43{
44 int err = 0;
45
46 if (unlikely(afinfo == NULL))
47 return -EINVAL;
48 if (unlikely(afinfo->family >= NPROTO))
49 return -EAFNOSUPPORT;
50 spin_lock_bh(&xfrm_input_afinfo_lock);
51 if (likely(xfrm_input_afinfo[afinfo->family] != NULL)) {
52 if (unlikely(xfrm_input_afinfo[afinfo->family] != afinfo))
53 err = -EINVAL;
54 else
55 RCU_INIT_POINTER(xfrm_input_afinfo[afinfo->family], NULL);
56 }
57 spin_unlock_bh(&xfrm_input_afinfo_lock);
58 synchronize_rcu();
59 return err;
60}
61EXPORT_SYMBOL(xfrm_input_unregister_afinfo);
62
63static struct xfrm_input_afinfo *xfrm_input_get_afinfo(unsigned int family)
64{
65 struct xfrm_input_afinfo *afinfo;
66
67 if (unlikely(family >= NPROTO))
68 return NULL;
69 rcu_read_lock();
70 afinfo = rcu_dereference(xfrm_input_afinfo[family]);
71 if (unlikely(!afinfo))
72 rcu_read_unlock();
73 return afinfo;
74}
75
76static void xfrm_input_put_afinfo(struct xfrm_input_afinfo *afinfo)
77{
78 rcu_read_unlock();
79}
80
81static int xfrm_rcv_cb(struct sk_buff *skb, unsigned int family, u8 protocol,
82 int err)
83{
84 int ret;
85 struct xfrm_input_afinfo *afinfo = xfrm_input_get_afinfo(family);
86
87 if (!afinfo)
88 return -EAFNOSUPPORT;
89
90 ret = afinfo->callback(skb, protocol, err);
91 xfrm_input_put_afinfo(afinfo);
92
93 return ret;
94}
95
96void __secpath_destroy(struct sec_path *sp)
97{
98 int i;
99 for (i = 0; i < sp->len; i++)
100 xfrm_state_put(sp->xvec[i]);
101 kmem_cache_free(secpath_cachep, sp);
102}
103EXPORT_SYMBOL(__secpath_destroy);
104
105struct sec_path *secpath_dup(struct sec_path *src)
106{
107 struct sec_path *sp;
108
109 sp = kmem_cache_alloc(secpath_cachep, GFP_ATOMIC);
110 if (!sp)
111 return NULL;
112
113 sp->len = 0;
114 if (src) {
115 int i;
116
117 memcpy(sp, src, sizeof(*sp));
118 for (i = 0; i < sp->len; i++)
119 xfrm_state_hold(sp->xvec[i]);
120 }
121 atomic_set(&sp->refcnt, 1);
122 return sp;
123}
124EXPORT_SYMBOL(secpath_dup);
125
126
127
128int xfrm_parse_spi(struct sk_buff *skb, u8 nexthdr, __be32 *spi, __be32 *seq)
129{
130 int offset, offset_seq;
131 int hlen;
132
133 switch (nexthdr) {
134 case IPPROTO_AH:
135 hlen = sizeof(struct ip_auth_hdr);
136 offset = offsetof(struct ip_auth_hdr, spi);
137 offset_seq = offsetof(struct ip_auth_hdr, seq_no);
138 break;
139 case IPPROTO_ESP:
140 hlen = sizeof(struct ip_esp_hdr);
141 offset = offsetof(struct ip_esp_hdr, spi);
142 offset_seq = offsetof(struct ip_esp_hdr, seq_no);
143 break;
144 case IPPROTO_COMP:
145 if (!pskb_may_pull(skb, sizeof(struct ip_comp_hdr)))
146 return -EINVAL;
147 *spi = htonl(ntohs(*(__be16 *)(skb_transport_header(skb) + 2)));
148 *seq = 0;
149 return 0;
150 default:
151 return 1;
152 }
153
154 if (!pskb_may_pull(skb, hlen))
155 return -EINVAL;
156
157 *spi = *(__be32 *)(skb_transport_header(skb) + offset);
158 *seq = *(__be32 *)(skb_transport_header(skb) + offset_seq);
159 return 0;
160}
161
162int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb)
163{
164 struct xfrm_mode *inner_mode = x->inner_mode;
165 int err;
166
167 err = x->outer_mode->afinfo->extract_input(x, skb);
168 if (err)
169 return err;
170
171 if (x->sel.family == AF_UNSPEC) {
172 inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
173 if (inner_mode == NULL)
174 return -EAFNOSUPPORT;
175 }
176
177 skb->protocol = inner_mode->afinfo->eth_proto;
178 return inner_mode->input2(x, skb);
179}
180EXPORT_SYMBOL(xfrm_prepare_input);
181
182int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
183{
184 struct net *net = dev_net(skb->dev);
185 int err;
186 __be32 seq;
187 __be32 seq_hi;
188 struct xfrm_state *x = NULL;
189 xfrm_address_t *daddr;
190 struct xfrm_mode *inner_mode;
191 u32 mark = skb->mark;
192 unsigned int family;
193 int decaps = 0;
194 int async = 0;
195
196
197 if (encap_type < 0) {
198 async = 1;
199 x = xfrm_input_state(skb);
200 seq = XFRM_SKB_CB(skb)->seq.input.low;
201 family = x->outer_mode->afinfo->family;
202 goto resume;
203 }
204
205 daddr = (xfrm_address_t *)(skb_network_header(skb) +
206 XFRM_SPI_SKB_CB(skb)->daddroff);
207 family = XFRM_SPI_SKB_CB(skb)->family;
208
209
210 if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4) {
211 switch (family) {
212 case AF_INET:
213 mark = be32_to_cpu(XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4->parms.i_key);
214 break;
215 case AF_INET6:
216 mark = be32_to_cpu(XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6->parms.i_key);
217 break;
218 }
219 }
220
221
222 if (!skb->sp || atomic_read(&skb->sp->refcnt) != 1) {
223 struct sec_path *sp;
224
225 sp = secpath_dup(skb->sp);
226 if (!sp) {
227 XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
228 goto drop;
229 }
230 if (skb->sp)
231 secpath_put(skb->sp);
232 skb->sp = sp;
233 }
234
235 seq = 0;
236 if (!spi && (err = xfrm_parse_spi(skb, nexthdr, &spi, &seq)) != 0) {
237 XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
238 goto drop;
239 }
240
241 do {
242 if (skb->sp->len == XFRM_MAX_DEPTH) {
243 XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
244 goto drop;
245 }
246
247 x = xfrm_state_lookup(net, mark, daddr, spi, nexthdr, family);
248 if (x == NULL) {
249 XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
250 xfrm_audit_state_notfound(skb, family, spi, seq);
251 goto drop;
252 }
253
254 skb->sp->xvec[skb->sp->len++] = x;
255
256 spin_lock(&x->lock);
257
258 if (unlikely(x->km.state != XFRM_STATE_VALID)) {
259 if (x->km.state == XFRM_STATE_ACQ)
260 XFRM_INC_STATS(net, LINUX_MIB_XFRMACQUIREERROR);
261 else
262 XFRM_INC_STATS(net,
263 LINUX_MIB_XFRMINSTATEINVALID);
264 goto drop_unlock;
265 }
266
267 if ((x->encap ? x->encap->encap_type : 0) != encap_type) {
268 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMISMATCH);
269 goto drop_unlock;
270 }
271
272 if (x->repl->check(x, skb, seq)) {
273 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
274 goto drop_unlock;
275 }
276
277 if (xfrm_state_check_expire(x)) {
278 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEEXPIRED);
279 goto drop_unlock;
280 }
281
282 spin_unlock(&x->lock);
283
284 if (xfrm_tunnel_check(skb, x, family)) {
285 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
286 goto drop;
287 }
288
289 seq_hi = htonl(xfrm_replay_seqhi(x, seq));
290
291 XFRM_SKB_CB(skb)->seq.input.low = seq;
292 XFRM_SKB_CB(skb)->seq.input.hi = seq_hi;
293
294 skb_dst_force(skb);
295
296 nexthdr = x->type->input(x, skb);
297
298 if (nexthdr == -EINPROGRESS)
299 return 0;
300resume:
301 spin_lock(&x->lock);
302 if (nexthdr <= 0) {
303 if (nexthdr == -EBADMSG) {
304 xfrm_audit_state_icvfail(x, skb,
305 x->type->proto);
306 x->stats.integrity_failed++;
307 }
308 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEPROTOERROR);
309 goto drop_unlock;
310 }
311
312
313 encap_type = 0;
314
315 if (async && x->repl->recheck(x, skb, seq)) {
316 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
317 goto drop_unlock;
318 }
319
320 x->repl->advance(x, seq);
321
322 x->curlft.bytes += skb->len;
323 x->curlft.packets++;
324
325 spin_unlock(&x->lock);
326
327 XFRM_MODE_SKB_CB(skb)->protocol = nexthdr;
328
329 inner_mode = x->inner_mode;
330
331 if (x->sel.family == AF_UNSPEC) {
332 inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
333 if (inner_mode == NULL)
334 goto drop;
335 }
336
337 if (inner_mode->input(x, skb)) {
338 XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEMODEERROR);
339 goto drop;
340 }
341
342 if (x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL) {
343 decaps = 1;
344 break;
345 }
346
347
348
349
350
351 daddr = &x->id.daddr;
352 family = x->outer_mode->afinfo->family;
353
354 err = xfrm_parse_spi(skb, nexthdr, &spi, &seq);
355 if (err < 0) {
356 XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
357 goto drop;
358 }
359 } while (!err);
360
361 err = xfrm_rcv_cb(skb, family, x->type->proto, 0);
362 if (err)
363 goto drop;
364
365 nf_reset(skb);
366
367 if (decaps) {
368 skb_dst_drop(skb);
369 netif_rx(skb);
370 return 0;
371 } else {
372 return x->inner_mode->afinfo->transport_finish(skb, async);
373 }
374
375drop_unlock:
376 spin_unlock(&x->lock);
377drop:
378 xfrm_rcv_cb(skb, family, x && x->type ? x->type->proto : nexthdr, -1);
379 kfree_skb(skb);
380 return 0;
381}
382EXPORT_SYMBOL(xfrm_input);
383
384int xfrm_input_resume(struct sk_buff *skb, int nexthdr)
385{
386 return xfrm_input(skb, nexthdr, 0, -1);
387}
388EXPORT_SYMBOL(xfrm_input_resume);
389
390void __init xfrm_input_init(void)
391{
392 secpath_cachep = kmem_cache_create("secpath_cache",
393 sizeof(struct sec_path),
394 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
395 NULL);
396}
397
