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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * IP Payload Compression Protocol (IPComp) - RFC3173.
4 *
5 * Copyright (c) 2003 James Morris <jmorris@intercode.com.au>
6 * Copyright (c) 2003-2008 Herbert Xu <herbert@gondor.apana.org.au>
7 *
8 * Todo:
9 * - Tunable compression parameters.
10 * - Compression stats.
11 * - Adaptive compression.
12 */
13
14#include <linux/crypto.h>
15#include <linux/err.h>
16#include <linux/list.h>
17#include <linux/module.h>
18#include <linux/mutex.h>
19#include <linux/percpu.h>
20#include <linux/slab.h>
21#include <linux/smp.h>
22#include <linux/vmalloc.h>
23#include <net/ip.h>
24#include <net/ipcomp.h>
25#include <net/xfrm.h>
26
27struct ipcomp_tfms {
28 struct list_head list;
29 struct crypto_comp * __percpu *tfms;
30 int users;
31};
32
33static DEFINE_MUTEX(ipcomp_resource_mutex);
34static void * __percpu *ipcomp_scratches;
35static int ipcomp_scratch_users;
36static LIST_HEAD(ipcomp_tfms_list);
37
38static int ipcomp_decompress(struct xfrm_state *x, struct sk_buff *skb)
39{
40 struct ipcomp_data *ipcd = x->data;
41 const int plen = skb->len;
42 int dlen = IPCOMP_SCRATCH_SIZE;
43 const u8 *start = skb->data;
44 u8 *scratch = *this_cpu_ptr(ipcomp_scratches);
45 struct crypto_comp *tfm = *this_cpu_ptr(ipcd->tfms);
46 int err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen);
47 int len;
48
49 if (err)
50 return err;
51
52 if (dlen < (plen + sizeof(struct ip_comp_hdr)))
53 return -EINVAL;
54
55 len = dlen - plen;
56 if (len > skb_tailroom(skb))
57 len = skb_tailroom(skb);
58
59 __skb_put(skb, len);
60
61 len += plen;
62 skb_copy_to_linear_data(skb, scratch, len);
63
64 while ((scratch += len, dlen -= len) > 0) {
65 skb_frag_t *frag;
66 struct page *page;
67
68 if (WARN_ON(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS))
69 return -EMSGSIZE;
70
71 frag = skb_shinfo(skb)->frags + skb_shinfo(skb)->nr_frags;
72 page = alloc_page(GFP_ATOMIC);
73
74 if (!page)
75 return -ENOMEM;
76
77 len = PAGE_SIZE;
78 if (dlen < len)
79 len = dlen;
80
81 skb_frag_fill_page_desc(frag, page, 0, len);
82 memcpy(skb_frag_address(frag), scratch, len);
83
84 skb->truesize += len;
85 skb->data_len += len;
86 skb->len += len;
87
88 skb_shinfo(skb)->nr_frags++;
89 }
90
91 return 0;
92}
93
94int ipcomp_input(struct xfrm_state *x, struct sk_buff *skb)
95{
96 int nexthdr;
97 int err = -ENOMEM;
98 struct ip_comp_hdr *ipch;
99
100 if (skb_linearize_cow(skb))
101 goto out;
102
103 skb->ip_summed = CHECKSUM_NONE;
104
105 /* Remove ipcomp header and decompress original payload */
106 ipch = (void *)skb->data;
107 nexthdr = ipch->nexthdr;
108
109 skb->transport_header = skb->network_header + sizeof(*ipch);
110 __skb_pull(skb, sizeof(*ipch));
111 err = ipcomp_decompress(x, skb);
112 if (err)
113 goto out;
114
115 err = nexthdr;
116
117out:
118 return err;
119}
120EXPORT_SYMBOL_GPL(ipcomp_input);
121
122static int ipcomp_compress(struct xfrm_state *x, struct sk_buff *skb)
123{
124 struct ipcomp_data *ipcd = x->data;
125 const int plen = skb->len;
126 int dlen = IPCOMP_SCRATCH_SIZE;
127 u8 *start = skb->data;
128 struct crypto_comp *tfm;
129 u8 *scratch;
130 int err;
131
132 local_bh_disable();
133 scratch = *this_cpu_ptr(ipcomp_scratches);
134 tfm = *this_cpu_ptr(ipcd->tfms);
135 err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
136 if (err)
137 goto out;
138
139 if ((dlen + sizeof(struct ip_comp_hdr)) >= plen) {
140 err = -EMSGSIZE;
141 goto out;
142 }
143
144 memcpy(start + sizeof(struct ip_comp_hdr), scratch, dlen);
145 local_bh_enable();
146
147 pskb_trim(skb, dlen + sizeof(struct ip_comp_hdr));
148 return 0;
149
150out:
151 local_bh_enable();
152 return err;
153}
154
155int ipcomp_output(struct xfrm_state *x, struct sk_buff *skb)
156{
157 int err;
158 struct ip_comp_hdr *ipch;
159 struct ipcomp_data *ipcd = x->data;
160
161 if (skb->len < ipcd->threshold) {
162 /* Don't bother compressing */
163 goto out_ok;
164 }
165
166 if (skb_linearize_cow(skb))
167 goto out_ok;
168
169 err = ipcomp_compress(x, skb);
170
171 if (err) {
172 goto out_ok;
173 }
174
175 /* Install ipcomp header, convert into ipcomp datagram. */
176 ipch = ip_comp_hdr(skb);
177 ipch->nexthdr = *skb_mac_header(skb);
178 ipch->flags = 0;
179 ipch->cpi = htons((u16 )ntohl(x->id.spi));
180 *skb_mac_header(skb) = IPPROTO_COMP;
181out_ok:
182 skb_push(skb, -skb_network_offset(skb));
183 return 0;
184}
185EXPORT_SYMBOL_GPL(ipcomp_output);
186
187static void ipcomp_free_scratches(void)
188{
189 int i;
190 void * __percpu *scratches;
191
192 if (--ipcomp_scratch_users)
193 return;
194
195 scratches = ipcomp_scratches;
196 if (!scratches)
197 return;
198
199 for_each_possible_cpu(i)
200 vfree(*per_cpu_ptr(scratches, i));
201
202 free_percpu(scratches);
203 ipcomp_scratches = NULL;
204}
205
206static void * __percpu *ipcomp_alloc_scratches(void)
207{
208 void * __percpu *scratches;
209 int i;
210
211 if (ipcomp_scratch_users++)
212 return ipcomp_scratches;
213
214 scratches = alloc_percpu(void *);
215 if (!scratches)
216 return NULL;
217
218 ipcomp_scratches = scratches;
219
220 for_each_possible_cpu(i) {
221 void *scratch;
222
223 scratch = vmalloc_node(IPCOMP_SCRATCH_SIZE, cpu_to_node(i));
224 if (!scratch)
225 return NULL;
226 *per_cpu_ptr(scratches, i) = scratch;
227 }
228
229 return scratches;
230}
231
232static void ipcomp_free_tfms(struct crypto_comp * __percpu *tfms)
233{
234 struct ipcomp_tfms *pos;
235 int cpu;
236
237 list_for_each_entry(pos, &ipcomp_tfms_list, list) {
238 if (pos->tfms == tfms)
239 break;
240 }
241
242 WARN_ON(list_entry_is_head(pos, &ipcomp_tfms_list, list));
243
244 if (--pos->users)
245 return;
246
247 list_del(&pos->list);
248 kfree(pos);
249
250 if (!tfms)
251 return;
252
253 for_each_possible_cpu(cpu) {
254 struct crypto_comp *tfm = *per_cpu_ptr(tfms, cpu);
255 crypto_free_comp(tfm);
256 }
257 free_percpu(tfms);
258}
259
260static struct crypto_comp * __percpu *ipcomp_alloc_tfms(const char *alg_name)
261{
262 struct ipcomp_tfms *pos;
263 struct crypto_comp * __percpu *tfms;
264 int cpu;
265
266
267 list_for_each_entry(pos, &ipcomp_tfms_list, list) {
268 struct crypto_comp *tfm;
269
270 /* This can be any valid CPU ID so we don't need locking. */
271 tfm = this_cpu_read(*pos->tfms);
272
273 if (!strcmp(crypto_comp_name(tfm), alg_name)) {
274 pos->users++;
275 return pos->tfms;
276 }
277 }
278
279 pos = kmalloc(sizeof(*pos), GFP_KERNEL);
280 if (!pos)
281 return NULL;
282
283 pos->users = 1;
284 INIT_LIST_HEAD(&pos->list);
285 list_add(&pos->list, &ipcomp_tfms_list);
286
287 pos->tfms = tfms = alloc_percpu(struct crypto_comp *);
288 if (!tfms)
289 goto error;
290
291 for_each_possible_cpu(cpu) {
292 struct crypto_comp *tfm = crypto_alloc_comp(alg_name, 0,
293 CRYPTO_ALG_ASYNC);
294 if (IS_ERR(tfm))
295 goto error;
296 *per_cpu_ptr(tfms, cpu) = tfm;
297 }
298
299 return tfms;
300
301error:
302 ipcomp_free_tfms(tfms);
303 return NULL;
304}
305
306static void ipcomp_free_data(struct ipcomp_data *ipcd)
307{
308 if (ipcd->tfms)
309 ipcomp_free_tfms(ipcd->tfms);
310 ipcomp_free_scratches();
311}
312
313void ipcomp_destroy(struct xfrm_state *x)
314{
315 struct ipcomp_data *ipcd = x->data;
316 if (!ipcd)
317 return;
318 xfrm_state_delete_tunnel(x);
319 mutex_lock(&ipcomp_resource_mutex);
320 ipcomp_free_data(ipcd);
321 mutex_unlock(&ipcomp_resource_mutex);
322 kfree(ipcd);
323}
324EXPORT_SYMBOL_GPL(ipcomp_destroy);
325
326int ipcomp_init_state(struct xfrm_state *x, struct netlink_ext_ack *extack)
327{
328 int err;
329 struct ipcomp_data *ipcd;
330 struct xfrm_algo_desc *calg_desc;
331
332 err = -EINVAL;
333 if (!x->calg) {
334 NL_SET_ERR_MSG(extack, "Missing required compression algorithm");
335 goto out;
336 }
337
338 if (x->encap) {
339 NL_SET_ERR_MSG(extack, "IPComp is not compatible with encapsulation");
340 goto out;
341 }
342
343 err = -ENOMEM;
344 ipcd = kzalloc(sizeof(*ipcd), GFP_KERNEL);
345 if (!ipcd)
346 goto out;
347
348 mutex_lock(&ipcomp_resource_mutex);
349 if (!ipcomp_alloc_scratches())
350 goto error;
351
352 ipcd->tfms = ipcomp_alloc_tfms(x->calg->alg_name);
353 if (!ipcd->tfms)
354 goto error;
355 mutex_unlock(&ipcomp_resource_mutex);
356
357 calg_desc = xfrm_calg_get_byname(x->calg->alg_name, 0);
358 BUG_ON(!calg_desc);
359 ipcd->threshold = calg_desc->uinfo.comp.threshold;
360 x->data = ipcd;
361 err = 0;
362out:
363 return err;
364
365error:
366 ipcomp_free_data(ipcd);
367 mutex_unlock(&ipcomp_resource_mutex);
368 kfree(ipcd);
369 goto out;
370}
371EXPORT_SYMBOL_GPL(ipcomp_init_state);
372
373MODULE_LICENSE("GPL");
374MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) - RFC3173");
375MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * IP Payload Compression Protocol (IPComp) - RFC3173.
4 *
5 * Copyright (c) 2003 James Morris <jmorris@intercode.com.au>
6 * Copyright (c) 2003-2008 Herbert Xu <herbert@gondor.apana.org.au>
7 *
8 * Todo:
9 * - Tunable compression parameters.
10 * - Compression stats.
11 * - Adaptive compression.
12 */
13
14#include <linux/crypto.h>
15#include <linux/err.h>
16#include <linux/list.h>
17#include <linux/module.h>
18#include <linux/mutex.h>
19#include <linux/percpu.h>
20#include <linux/slab.h>
21#include <linux/smp.h>
22#include <linux/vmalloc.h>
23#include <net/ip.h>
24#include <net/ipcomp.h>
25#include <net/xfrm.h>
26
27struct ipcomp_tfms {
28 struct list_head list;
29 struct crypto_comp * __percpu *tfms;
30 int users;
31};
32
33static DEFINE_MUTEX(ipcomp_resource_mutex);
34static void * __percpu *ipcomp_scratches;
35static int ipcomp_scratch_users;
36static LIST_HEAD(ipcomp_tfms_list);
37
38static int ipcomp_decompress(struct xfrm_state *x, struct sk_buff *skb)
39{
40 struct ipcomp_data *ipcd = x->data;
41 const int plen = skb->len;
42 int dlen = IPCOMP_SCRATCH_SIZE;
43 const u8 *start = skb->data;
44 u8 *scratch = *this_cpu_ptr(ipcomp_scratches);
45 struct crypto_comp *tfm = *this_cpu_ptr(ipcd->tfms);
46 int err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen);
47 int len;
48
49 if (err)
50 return err;
51
52 if (dlen < (plen + sizeof(struct ip_comp_hdr)))
53 return -EINVAL;
54
55 len = dlen - plen;
56 if (len > skb_tailroom(skb))
57 len = skb_tailroom(skb);
58
59 __skb_put(skb, len);
60
61 len += plen;
62 skb_copy_to_linear_data(skb, scratch, len);
63
64 while ((scratch += len, dlen -= len) > 0) {
65 skb_frag_t *frag;
66 struct page *page;
67
68 if (WARN_ON(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS))
69 return -EMSGSIZE;
70
71 frag = skb_shinfo(skb)->frags + skb_shinfo(skb)->nr_frags;
72 page = alloc_page(GFP_ATOMIC);
73
74 if (!page)
75 return -ENOMEM;
76
77 __skb_frag_set_page(frag, page);
78
79 len = PAGE_SIZE;
80 if (dlen < len)
81 len = dlen;
82
83 skb_frag_off_set(frag, 0);
84 skb_frag_size_set(frag, len);
85 memcpy(skb_frag_address(frag), scratch, len);
86
87 skb->truesize += len;
88 skb->data_len += len;
89 skb->len += len;
90
91 skb_shinfo(skb)->nr_frags++;
92 }
93
94 return 0;
95}
96
97int ipcomp_input(struct xfrm_state *x, struct sk_buff *skb)
98{
99 int nexthdr;
100 int err = -ENOMEM;
101 struct ip_comp_hdr *ipch;
102
103 if (skb_linearize_cow(skb))
104 goto out;
105
106 skb->ip_summed = CHECKSUM_NONE;
107
108 /* Remove ipcomp header and decompress original payload */
109 ipch = (void *)skb->data;
110 nexthdr = ipch->nexthdr;
111
112 skb->transport_header = skb->network_header + sizeof(*ipch);
113 __skb_pull(skb, sizeof(*ipch));
114 err = ipcomp_decompress(x, skb);
115 if (err)
116 goto out;
117
118 err = nexthdr;
119
120out:
121 return err;
122}
123EXPORT_SYMBOL_GPL(ipcomp_input);
124
125static int ipcomp_compress(struct xfrm_state *x, struct sk_buff *skb)
126{
127 struct ipcomp_data *ipcd = x->data;
128 const int plen = skb->len;
129 int dlen = IPCOMP_SCRATCH_SIZE;
130 u8 *start = skb->data;
131 struct crypto_comp *tfm;
132 u8 *scratch;
133 int err;
134
135 local_bh_disable();
136 scratch = *this_cpu_ptr(ipcomp_scratches);
137 tfm = *this_cpu_ptr(ipcd->tfms);
138 err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
139 if (err)
140 goto out;
141
142 if ((dlen + sizeof(struct ip_comp_hdr)) >= plen) {
143 err = -EMSGSIZE;
144 goto out;
145 }
146
147 memcpy(start + sizeof(struct ip_comp_hdr), scratch, dlen);
148 local_bh_enable();
149
150 pskb_trim(skb, dlen + sizeof(struct ip_comp_hdr));
151 return 0;
152
153out:
154 local_bh_enable();
155 return err;
156}
157
158int ipcomp_output(struct xfrm_state *x, struct sk_buff *skb)
159{
160 int err;
161 struct ip_comp_hdr *ipch;
162 struct ipcomp_data *ipcd = x->data;
163
164 if (skb->len < ipcd->threshold) {
165 /* Don't bother compressing */
166 goto out_ok;
167 }
168
169 if (skb_linearize_cow(skb))
170 goto out_ok;
171
172 err = ipcomp_compress(x, skb);
173
174 if (err) {
175 goto out_ok;
176 }
177
178 /* Install ipcomp header, convert into ipcomp datagram. */
179 ipch = ip_comp_hdr(skb);
180 ipch->nexthdr = *skb_mac_header(skb);
181 ipch->flags = 0;
182 ipch->cpi = htons((u16 )ntohl(x->id.spi));
183 *skb_mac_header(skb) = IPPROTO_COMP;
184out_ok:
185 skb_push(skb, -skb_network_offset(skb));
186 return 0;
187}
188EXPORT_SYMBOL_GPL(ipcomp_output);
189
190static void ipcomp_free_scratches(void)
191{
192 int i;
193 void * __percpu *scratches;
194
195 if (--ipcomp_scratch_users)
196 return;
197
198 scratches = ipcomp_scratches;
199 if (!scratches)
200 return;
201
202 for_each_possible_cpu(i)
203 vfree(*per_cpu_ptr(scratches, i));
204
205 free_percpu(scratches);
206}
207
208static void * __percpu *ipcomp_alloc_scratches(void)
209{
210 void * __percpu *scratches;
211 int i;
212
213 if (ipcomp_scratch_users++)
214 return ipcomp_scratches;
215
216 scratches = alloc_percpu(void *);
217 if (!scratches)
218 return NULL;
219
220 ipcomp_scratches = scratches;
221
222 for_each_possible_cpu(i) {
223 void *scratch;
224
225 scratch = vmalloc_node(IPCOMP_SCRATCH_SIZE, cpu_to_node(i));
226 if (!scratch)
227 return NULL;
228 *per_cpu_ptr(scratches, i) = scratch;
229 }
230
231 return scratches;
232}
233
234static void ipcomp_free_tfms(struct crypto_comp * __percpu *tfms)
235{
236 struct ipcomp_tfms *pos;
237 int cpu;
238
239 list_for_each_entry(pos, &ipcomp_tfms_list, list) {
240 if (pos->tfms == tfms)
241 break;
242 }
243
244 WARN_ON(list_entry_is_head(pos, &ipcomp_tfms_list, list));
245
246 if (--pos->users)
247 return;
248
249 list_del(&pos->list);
250 kfree(pos);
251
252 if (!tfms)
253 return;
254
255 for_each_possible_cpu(cpu) {
256 struct crypto_comp *tfm = *per_cpu_ptr(tfms, cpu);
257 crypto_free_comp(tfm);
258 }
259 free_percpu(tfms);
260}
261
262static struct crypto_comp * __percpu *ipcomp_alloc_tfms(const char *alg_name)
263{
264 struct ipcomp_tfms *pos;
265 struct crypto_comp * __percpu *tfms;
266 int cpu;
267
268
269 list_for_each_entry(pos, &ipcomp_tfms_list, list) {
270 struct crypto_comp *tfm;
271
272 /* This can be any valid CPU ID so we don't need locking. */
273 tfm = this_cpu_read(*pos->tfms);
274
275 if (!strcmp(crypto_comp_name(tfm), alg_name)) {
276 pos->users++;
277 return pos->tfms;
278 }
279 }
280
281 pos = kmalloc(sizeof(*pos), GFP_KERNEL);
282 if (!pos)
283 return NULL;
284
285 pos->users = 1;
286 INIT_LIST_HEAD(&pos->list);
287 list_add(&pos->list, &ipcomp_tfms_list);
288
289 pos->tfms = tfms = alloc_percpu(struct crypto_comp *);
290 if (!tfms)
291 goto error;
292
293 for_each_possible_cpu(cpu) {
294 struct crypto_comp *tfm = crypto_alloc_comp(alg_name, 0,
295 CRYPTO_ALG_ASYNC);
296 if (IS_ERR(tfm))
297 goto error;
298 *per_cpu_ptr(tfms, cpu) = tfm;
299 }
300
301 return tfms;
302
303error:
304 ipcomp_free_tfms(tfms);
305 return NULL;
306}
307
308static void ipcomp_free_data(struct ipcomp_data *ipcd)
309{
310 if (ipcd->tfms)
311 ipcomp_free_tfms(ipcd->tfms);
312 ipcomp_free_scratches();
313}
314
315void ipcomp_destroy(struct xfrm_state *x)
316{
317 struct ipcomp_data *ipcd = x->data;
318 if (!ipcd)
319 return;
320 xfrm_state_delete_tunnel(x);
321 mutex_lock(&ipcomp_resource_mutex);
322 ipcomp_free_data(ipcd);
323 mutex_unlock(&ipcomp_resource_mutex);
324 kfree(ipcd);
325}
326EXPORT_SYMBOL_GPL(ipcomp_destroy);
327
328int ipcomp_init_state(struct xfrm_state *x)
329{
330 int err;
331 struct ipcomp_data *ipcd;
332 struct xfrm_algo_desc *calg_desc;
333
334 err = -EINVAL;
335 if (!x->calg)
336 goto out;
337
338 if (x->encap)
339 goto out;
340
341 err = -ENOMEM;
342 ipcd = kzalloc(sizeof(*ipcd), GFP_KERNEL);
343 if (!ipcd)
344 goto out;
345
346 mutex_lock(&ipcomp_resource_mutex);
347 if (!ipcomp_alloc_scratches())
348 goto error;
349
350 ipcd->tfms = ipcomp_alloc_tfms(x->calg->alg_name);
351 if (!ipcd->tfms)
352 goto error;
353 mutex_unlock(&ipcomp_resource_mutex);
354
355 calg_desc = xfrm_calg_get_byname(x->calg->alg_name, 0);
356 BUG_ON(!calg_desc);
357 ipcd->threshold = calg_desc->uinfo.comp.threshold;
358 x->data = ipcd;
359 err = 0;
360out:
361 return err;
362
363error:
364 ipcomp_free_data(ipcd);
365 mutex_unlock(&ipcomp_resource_mutex);
366 kfree(ipcd);
367 goto out;
368}
369EXPORT_SYMBOL_GPL(ipcomp_init_state);
370
371MODULE_LICENSE("GPL");
372MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) - RFC3173");
373MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");