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-rw-r--r--net/xfrm/Kconfig6
-rw-r--r--net/xfrm/Makefile1
-rw-r--r--net/xfrm/xfrm_ipcomp.c349
3 files changed, 356 insertions, 0 deletions
diff --git a/net/xfrm/Kconfig b/net/xfrm/Kconfig
index 9201ef8ad90e..6d081674515f 100644
--- a/net/xfrm/Kconfig
+++ b/net/xfrm/Kconfig
@@ -46,6 +46,12 @@ config XFRM_STATISTICS
46 46
47 If unsure, say N. 47 If unsure, say N.
48 48
49config XFRM_IPCOMP
50 tristate
51 select XFRM
52 select CRYPTO
53 select CRYPTO_DEFLATE
54
49config NET_KEY 55config NET_KEY
50 tristate "PF_KEY sockets" 56 tristate "PF_KEY sockets"
51 select XFRM 57 select XFRM
diff --git a/net/xfrm/Makefile b/net/xfrm/Makefile
index 332cfb0ff566..0f439a72ccab 100644
--- a/net/xfrm/Makefile
+++ b/net/xfrm/Makefile
@@ -6,4 +6,5 @@ obj-$(CONFIG_XFRM) := xfrm_policy.o xfrm_state.o xfrm_hash.o \
6 xfrm_input.o xfrm_output.o xfrm_algo.o 6 xfrm_input.o xfrm_output.o xfrm_algo.o
7obj-$(CONFIG_XFRM_STATISTICS) += xfrm_proc.o 7obj-$(CONFIG_XFRM_STATISTICS) += xfrm_proc.o
8obj-$(CONFIG_XFRM_USER) += xfrm_user.o 8obj-$(CONFIG_XFRM_USER) += xfrm_user.o
9obj-$(CONFIG_XFRM_IPCOMP) += xfrm_ipcomp.o
9 10
diff --git a/net/xfrm/xfrm_ipcomp.c b/net/xfrm/xfrm_ipcomp.c
new file mode 100644
index 000000000000..b51e804fbbad
--- /dev/null
+++ b/net/xfrm/xfrm_ipcomp.c
@@ -0,0 +1,349 @@
1/*
2 * IP Payload Compression Protocol (IPComp) - RFC3173.
3 *
4 * Copyright (c) 2003 James Morris <jmorris@intercode.com.au>
5 * Copyright (c) 2003-2008 Herbert Xu <herbert@gondor.apana.org.au>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the Free
9 * Software Foundation; either version 2 of the License, or (at your option)
10 * any later version.
11 *
12 * Todo:
13 * - Tunable compression parameters.
14 * - Compression stats.
15 * - Adaptive compression.
16 */
17
18#include <linux/crypto.h>
19#include <linux/err.h>
20#include <linux/list.h>
21#include <linux/module.h>
22#include <linux/mutex.h>
23#include <linux/percpu.h>
24#include <linux/rtnetlink.h>
25#include <linux/smp.h>
26#include <linux/vmalloc.h>
27#include <net/ip.h>
28#include <net/ipcomp.h>
29#include <net/xfrm.h>
30
31struct ipcomp_tfms {
32 struct list_head list;
33 struct crypto_comp **tfms;
34 int users;
35};
36
37static DEFINE_MUTEX(ipcomp_resource_mutex);
38static void **ipcomp_scratches;
39static int ipcomp_scratch_users;
40static LIST_HEAD(ipcomp_tfms_list);
41
42static int ipcomp_decompress(struct xfrm_state *x, struct sk_buff *skb)
43{
44 struct ipcomp_data *ipcd = x->data;
45 const int plen = skb->len;
46 int dlen = IPCOMP_SCRATCH_SIZE;
47 const u8 *start = skb->data;
48 const int cpu = get_cpu();
49 u8 *scratch = *per_cpu_ptr(ipcomp_scratches, cpu);
50 struct crypto_comp *tfm = *per_cpu_ptr(ipcd->tfms, cpu);
51 int err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen);
52
53 if (err)
54 goto out;
55
56 if (dlen < (plen + sizeof(struct ip_comp_hdr))) {
57 err = -EINVAL;
58 goto out;
59 }
60
61 err = pskb_expand_head(skb, 0, dlen - plen, GFP_ATOMIC);
62 if (err)
63 goto out;
64
65 skb->truesize += dlen - plen;
66 __skb_put(skb, dlen - plen);
67 skb_copy_to_linear_data(skb, scratch, dlen);
68out:
69 put_cpu();
70 return err;
71}
72
73int ipcomp_input(struct xfrm_state *x, struct sk_buff *skb)
74{
75 int nexthdr;
76 int err = -ENOMEM;
77 struct ip_comp_hdr *ipch;
78
79 if (skb_linearize_cow(skb))
80 goto out;
81
82 skb->ip_summed = CHECKSUM_NONE;
83
84 /* Remove ipcomp header and decompress original payload */
85 ipch = (void *)skb->data;
86 nexthdr = ipch->nexthdr;
87
88 skb->transport_header = skb->network_header + sizeof(*ipch);
89 __skb_pull(skb, sizeof(*ipch));
90 err = ipcomp_decompress(x, skb);
91 if (err)
92 goto out;
93
94 err = nexthdr;
95
96out:
97 return err;
98}
99EXPORT_SYMBOL_GPL(ipcomp_input);
100
101static int ipcomp_compress(struct xfrm_state *x, struct sk_buff *skb)
102{
103 struct ipcomp_data *ipcd = x->data;
104 const int plen = skb->len;
105 int dlen = IPCOMP_SCRATCH_SIZE;
106 u8 *start = skb->data;
107 const int cpu = get_cpu();
108 u8 *scratch = *per_cpu_ptr(ipcomp_scratches, cpu);
109 struct crypto_comp *tfm = *per_cpu_ptr(ipcd->tfms, cpu);
110 int err;
111
112 local_bh_disable();
113 err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
114 local_bh_enable();
115 if (err)
116 goto out;
117
118 if ((dlen + sizeof(struct ip_comp_hdr)) >= plen) {
119 err = -EMSGSIZE;
120 goto out;
121 }
122
123 memcpy(start + sizeof(struct ip_comp_hdr), scratch, dlen);
124 put_cpu();
125
126 pskb_trim(skb, dlen + sizeof(struct ip_comp_hdr));
127 return 0;
128
129out:
130 put_cpu();
131 return err;
132}
133
134int ipcomp_output(struct xfrm_state *x, struct sk_buff *skb)
135{
136 int err;
137 struct ip_comp_hdr *ipch;
138 struct ipcomp_data *ipcd = x->data;
139
140 if (skb->len < ipcd->threshold) {
141 /* Don't bother compressing */
142 goto out_ok;
143 }
144
145 if (skb_linearize_cow(skb))
146 goto out_ok;
147
148 err = ipcomp_compress(x, skb);
149
150 if (err) {
151 goto out_ok;
152 }
153
154 /* Install ipcomp header, convert into ipcomp datagram. */
155 ipch = ip_comp_hdr(skb);
156 ipch->nexthdr = *skb_mac_header(skb);
157 ipch->flags = 0;
158 ipch->cpi = htons((u16 )ntohl(x->id.spi));
159 *skb_mac_header(skb) = IPPROTO_COMP;
160out_ok:
161 skb_push(skb, -skb_network_offset(skb));
162 return 0;
163}
164EXPORT_SYMBOL_GPL(ipcomp_output);
165
166static void ipcomp_free_scratches(void)
167{
168 int i;
169 void **scratches;
170
171 if (--ipcomp_scratch_users)
172 return;
173
174 scratches = ipcomp_scratches;
175 if (!scratches)
176 return;
177
178 for_each_possible_cpu(i)
179 vfree(*per_cpu_ptr(scratches, i));
180
181 free_percpu(scratches);
182}
183
184static void **ipcomp_alloc_scratches(void)
185{
186 int i;
187 void **scratches;
188
189 if (ipcomp_scratch_users++)
190 return ipcomp_scratches;
191
192 scratches = alloc_percpu(void *);
193 if (!scratches)
194 return NULL;
195
196 ipcomp_scratches = scratches;
197
198 for_each_possible_cpu(i) {
199 void *scratch = vmalloc(IPCOMP_SCRATCH_SIZE);
200 if (!scratch)
201 return NULL;
202 *per_cpu_ptr(scratches, i) = scratch;
203 }
204
205 return scratches;
206}
207
208static void ipcomp_free_tfms(struct crypto_comp **tfms)
209{
210 struct ipcomp_tfms *pos;
211 int cpu;
212
213 list_for_each_entry(pos, &ipcomp_tfms_list, list) {
214 if (pos->tfms == tfms)
215 break;
216 }
217
218 BUG_TRAP(pos);
219
220 if (--pos->users)
221 return;
222
223 list_del(&pos->list);
224 kfree(pos);
225
226 if (!tfms)
227 return;
228
229 for_each_possible_cpu(cpu) {
230 struct crypto_comp *tfm = *per_cpu_ptr(tfms, cpu);
231 crypto_free_comp(tfm);
232 }
233 free_percpu(tfms);
234}
235
236static struct crypto_comp **ipcomp_alloc_tfms(const char *alg_name)
237{
238 struct ipcomp_tfms *pos;
239 struct crypto_comp **tfms;
240 int cpu;
241
242 /* This can be any valid CPU ID so we don't need locking. */
243 cpu = raw_smp_processor_id();
244
245 list_for_each_entry(pos, &ipcomp_tfms_list, list) {
246 struct crypto_comp *tfm;
247
248 tfms = pos->tfms;
249 tfm = *per_cpu_ptr(tfms, cpu);
250
251 if (!strcmp(crypto_comp_name(tfm), alg_name)) {
252 pos->users++;
253 return tfms;
254 }
255 }
256
257 pos = kmalloc(sizeof(*pos), GFP_KERNEL);
258 if (!pos)
259 return NULL;
260
261 pos->users = 1;
262 INIT_LIST_HEAD(&pos->list);
263 list_add(&pos->list, &ipcomp_tfms_list);
264
265 pos->tfms = tfms = alloc_percpu(struct crypto_comp *);
266 if (!tfms)
267 goto error;
268
269 for_each_possible_cpu(cpu) {
270 struct crypto_comp *tfm = crypto_alloc_comp(alg_name, 0,
271 CRYPTO_ALG_ASYNC);
272 if (IS_ERR(tfm))
273 goto error;
274 *per_cpu_ptr(tfms, cpu) = tfm;
275 }
276
277 return tfms;
278
279error:
280 ipcomp_free_tfms(tfms);
281 return NULL;
282}
283
284static void ipcomp_free_data(struct ipcomp_data *ipcd)
285{
286 if (ipcd->tfms)
287 ipcomp_free_tfms(ipcd->tfms);
288 ipcomp_free_scratches();
289}
290
291void ipcomp_destroy(struct xfrm_state *x)
292{
293 struct ipcomp_data *ipcd = x->data;
294 if (!ipcd)
295 return;
296 xfrm_state_delete_tunnel(x);
297 mutex_lock(&ipcomp_resource_mutex);
298 ipcomp_free_data(ipcd);
299 mutex_unlock(&ipcomp_resource_mutex);
300 kfree(ipcd);
301}
302EXPORT_SYMBOL_GPL(ipcomp_destroy);
303
304int ipcomp_init_state(struct xfrm_state *x)
305{
306 int err;
307 struct ipcomp_data *ipcd;
308 struct xfrm_algo_desc *calg_desc;
309
310 err = -EINVAL;
311 if (!x->calg)
312 goto out;
313
314 if (x->encap)
315 goto out;
316
317 err = -ENOMEM;
318 ipcd = kzalloc(sizeof(*ipcd), GFP_KERNEL);
319 if (!ipcd)
320 goto out;
321
322 mutex_lock(&ipcomp_resource_mutex);
323 if (!ipcomp_alloc_scratches())
324 goto error;
325
326 ipcd->tfms = ipcomp_alloc_tfms(x->calg->alg_name);
327 if (!ipcd->tfms)
328 goto error;
329 mutex_unlock(&ipcomp_resource_mutex);
330
331 calg_desc = xfrm_calg_get_byname(x->calg->alg_name, 0);
332 BUG_ON(!calg_desc);
333 ipcd->threshold = calg_desc->uinfo.comp.threshold;
334 x->data = ipcd;
335 err = 0;
336out:
337 return err;
338
339error:
340 ipcomp_free_data(ipcd);
341 mutex_unlock(&ipcomp_resource_mutex);
342 kfree(ipcd);
343 goto out;
344}
345EXPORT_SYMBOL_GPL(ipcomp_init_state);
346
347MODULE_LICENSE("GPL");
348MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) - RFC3173");
349MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");