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