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v5.14.15
  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>");
v5.4
  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	const int cpu = get_cpu();
 45	u8 *scratch = *per_cpu_ptr(ipcomp_scratches, cpu);
 46	struct crypto_comp *tfm = *per_cpu_ptr(ipcd->tfms, cpu);
 47	int err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen);
 48	int len;
 49
 50	if (err)
 51		goto out;
 52
 53	if (dlen < (plen + sizeof(struct ip_comp_hdr))) {
 54		err = -EINVAL;
 55		goto out;
 56	}
 57
 58	len = dlen - plen;
 59	if (len > skb_tailroom(skb))
 60		len = skb_tailroom(skb);
 61
 62	__skb_put(skb, len);
 63
 64	len += plen;
 65	skb_copy_to_linear_data(skb, scratch, len);
 66
 67	while ((scratch += len, dlen -= len) > 0) {
 68		skb_frag_t *frag;
 69		struct page *page;
 70
 71		err = -EMSGSIZE;
 72		if (WARN_ON(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS))
 73			goto out;
 74
 75		frag = skb_shinfo(skb)->frags + skb_shinfo(skb)->nr_frags;
 76		page = alloc_page(GFP_ATOMIC);
 77
 78		err = -ENOMEM;
 79		if (!page)
 80			goto out;
 81
 82		__skb_frag_set_page(frag, page);
 83
 84		len = PAGE_SIZE;
 85		if (dlen < len)
 86			len = dlen;
 87
 88		skb_frag_off_set(frag, 0);
 89		skb_frag_size_set(frag, len);
 90		memcpy(skb_frag_address(frag), scratch, len);
 91
 92		skb->truesize += len;
 93		skb->data_len += len;
 94		skb->len += len;
 95
 96		skb_shinfo(skb)->nr_frags++;
 97	}
 98
 99	err = 0;
100
101out:
102	put_cpu();
103	return err;
104}
105
106int ipcomp_input(struct xfrm_state *x, struct sk_buff *skb)
107{
108	int nexthdr;
109	int err = -ENOMEM;
110	struct ip_comp_hdr *ipch;
111
112	if (skb_linearize_cow(skb))
113		goto out;
114
115	skb->ip_summed = CHECKSUM_NONE;
116
117	/* Remove ipcomp header and decompress original payload */
118	ipch = (void *)skb->data;
119	nexthdr = ipch->nexthdr;
120
121	skb->transport_header = skb->network_header + sizeof(*ipch);
122	__skb_pull(skb, sizeof(*ipch));
123	err = ipcomp_decompress(x, skb);
124	if (err)
125		goto out;
126
127	err = nexthdr;
128
129out:
130	return err;
131}
132EXPORT_SYMBOL_GPL(ipcomp_input);
133
134static int ipcomp_compress(struct xfrm_state *x, struct sk_buff *skb)
135{
136	struct ipcomp_data *ipcd = x->data;
137	const int plen = skb->len;
138	int dlen = IPCOMP_SCRATCH_SIZE;
139	u8 *start = skb->data;
140	struct crypto_comp *tfm;
141	u8 *scratch;
142	int err;
143
144	local_bh_disable();
145	scratch = *this_cpu_ptr(ipcomp_scratches);
146	tfm = *this_cpu_ptr(ipcd->tfms);
147	err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
148	if (err)
149		goto out;
150
151	if ((dlen + sizeof(struct ip_comp_hdr)) >= plen) {
152		err = -EMSGSIZE;
153		goto out;
154	}
155
156	memcpy(start + sizeof(struct ip_comp_hdr), scratch, dlen);
157	local_bh_enable();
158
159	pskb_trim(skb, dlen + sizeof(struct ip_comp_hdr));
160	return 0;
161
162out:
163	local_bh_enable();
164	return err;
165}
166
167int ipcomp_output(struct xfrm_state *x, struct sk_buff *skb)
168{
169	int err;
170	struct ip_comp_hdr *ipch;
171	struct ipcomp_data *ipcd = x->data;
172
173	if (skb->len < ipcd->threshold) {
174		/* Don't bother compressing */
175		goto out_ok;
176	}
177
178	if (skb_linearize_cow(skb))
179		goto out_ok;
180
181	err = ipcomp_compress(x, skb);
182
183	if (err) {
184		goto out_ok;
185	}
186
187	/* Install ipcomp header, convert into ipcomp datagram. */
188	ipch = ip_comp_hdr(skb);
189	ipch->nexthdr = *skb_mac_header(skb);
190	ipch->flags = 0;
191	ipch->cpi = htons((u16 )ntohl(x->id.spi));
192	*skb_mac_header(skb) = IPPROTO_COMP;
193out_ok:
194	skb_push(skb, -skb_network_offset(skb));
195	return 0;
196}
197EXPORT_SYMBOL_GPL(ipcomp_output);
198
199static void ipcomp_free_scratches(void)
200{
201	int i;
202	void * __percpu *scratches;
203
204	if (--ipcomp_scratch_users)
205		return;
206
207	scratches = ipcomp_scratches;
208	if (!scratches)
209		return;
210
211	for_each_possible_cpu(i)
212		vfree(*per_cpu_ptr(scratches, i));
213
214	free_percpu(scratches);
215}
216
217static void * __percpu *ipcomp_alloc_scratches(void)
218{
219	void * __percpu *scratches;
220	int i;
221
222	if (ipcomp_scratch_users++)
223		return ipcomp_scratches;
224
225	scratches = alloc_percpu(void *);
226	if (!scratches)
227		return NULL;
228
229	ipcomp_scratches = scratches;
230
231	for_each_possible_cpu(i) {
232		void *scratch;
233
234		scratch = vmalloc_node(IPCOMP_SCRATCH_SIZE, cpu_to_node(i));
235		if (!scratch)
236			return NULL;
237		*per_cpu_ptr(scratches, i) = scratch;
238	}
239
240	return scratches;
241}
242
243static void ipcomp_free_tfms(struct crypto_comp * __percpu *tfms)
244{
245	struct ipcomp_tfms *pos;
246	int cpu;
247
248	list_for_each_entry(pos, &ipcomp_tfms_list, list) {
249		if (pos->tfms == tfms)
250			break;
251	}
252
253	WARN_ON(!pos);
254
255	if (--pos->users)
256		return;
257
258	list_del(&pos->list);
259	kfree(pos);
260
261	if (!tfms)
262		return;
263
264	for_each_possible_cpu(cpu) {
265		struct crypto_comp *tfm = *per_cpu_ptr(tfms, cpu);
266		crypto_free_comp(tfm);
267	}
268	free_percpu(tfms);
269}
270
271static struct crypto_comp * __percpu *ipcomp_alloc_tfms(const char *alg_name)
272{
273	struct ipcomp_tfms *pos;
274	struct crypto_comp * __percpu *tfms;
275	int cpu;
276
277
278	list_for_each_entry(pos, &ipcomp_tfms_list, list) {
279		struct crypto_comp *tfm;
280
281		/* This can be any valid CPU ID so we don't need locking. */
282		tfm = this_cpu_read(*pos->tfms);
283
284		if (!strcmp(crypto_comp_name(tfm), alg_name)) {
285			pos->users++;
286			return pos->tfms;
287		}
288	}
289
290	pos = kmalloc(sizeof(*pos), GFP_KERNEL);
291	if (!pos)
292		return NULL;
293
294	pos->users = 1;
295	INIT_LIST_HEAD(&pos->list);
296	list_add(&pos->list, &ipcomp_tfms_list);
297
298	pos->tfms = tfms = alloc_percpu(struct crypto_comp *);
299	if (!tfms)
300		goto error;
301
302	for_each_possible_cpu(cpu) {
303		struct crypto_comp *tfm = crypto_alloc_comp(alg_name, 0,
304							    CRYPTO_ALG_ASYNC);
305		if (IS_ERR(tfm))
306			goto error;
307		*per_cpu_ptr(tfms, cpu) = tfm;
308	}
309
310	return tfms;
311
312error:
313	ipcomp_free_tfms(tfms);
314	return NULL;
315}
316
317static void ipcomp_free_data(struct ipcomp_data *ipcd)
318{
319	if (ipcd->tfms)
320		ipcomp_free_tfms(ipcd->tfms);
321	ipcomp_free_scratches();
322}
323
324void ipcomp_destroy(struct xfrm_state *x)
325{
326	struct ipcomp_data *ipcd = x->data;
327	if (!ipcd)
328		return;
329	xfrm_state_delete_tunnel(x);
330	mutex_lock(&ipcomp_resource_mutex);
331	ipcomp_free_data(ipcd);
332	mutex_unlock(&ipcomp_resource_mutex);
333	kfree(ipcd);
334}
335EXPORT_SYMBOL_GPL(ipcomp_destroy);
336
337int ipcomp_init_state(struct xfrm_state *x)
338{
339	int err;
340	struct ipcomp_data *ipcd;
341	struct xfrm_algo_desc *calg_desc;
342
343	err = -EINVAL;
344	if (!x->calg)
345		goto out;
346
347	if (x->encap)
348		goto out;
349
350	err = -ENOMEM;
351	ipcd = kzalloc(sizeof(*ipcd), GFP_KERNEL);
352	if (!ipcd)
353		goto out;
354
355	mutex_lock(&ipcomp_resource_mutex);
356	if (!ipcomp_alloc_scratches())
357		goto error;
358
359	ipcd->tfms = ipcomp_alloc_tfms(x->calg->alg_name);
360	if (!ipcd->tfms)
361		goto error;
362	mutex_unlock(&ipcomp_resource_mutex);
363
364	calg_desc = xfrm_calg_get_byname(x->calg->alg_name, 0);
365	BUG_ON(!calg_desc);
366	ipcd->threshold = calg_desc->uinfo.comp.threshold;
367	x->data = ipcd;
368	err = 0;
369out:
370	return err;
371
372error:
373	ipcomp_free_data(ipcd);
374	mutex_unlock(&ipcomp_resource_mutex);
375	kfree(ipcd);
376	goto out;
377}
378EXPORT_SYMBOL_GPL(ipcomp_init_state);
379
380MODULE_LICENSE("GPL");
381MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) - RFC3173");
382MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");