Loading...
1/* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001 Intel Corp.
6 *
7 * This file is part of the SCTP kernel implementation
8 *
9 * These functions manipulate sctp tsn mapping array.
10 *
11 * This SCTP implementation is free software;
12 * you can redistribute it and/or modify it under the terms of
13 * the GNU General Public License as published by
14 * the Free Software Foundation; either version 2, or (at your option)
15 * any later version.
16 *
17 * This SCTP implementation is distributed in the hope that it
18 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
19 * ************************
20 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
21 * See the GNU General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License
24 * along with GNU CC; see the file COPYING. If not, write to
25 * the Free Software Foundation, 59 Temple Place - Suite 330,
26 * Boston, MA 02111-1307, USA.
27 *
28 * Please send any bug reports or fixes you make to the
29 * email address(es):
30 * lksctp developers <lksctp-developers@lists.sourceforge.net>
31 *
32 * Or submit a bug report through the following website:
33 * http://www.sf.net/projects/lksctp
34 *
35 * Written or modified by:
36 * La Monte H.P. Yarroll <piggy@acm.org>
37 * Jon Grimm <jgrimm@us.ibm.com>
38 * Karl Knutson <karl@athena.chicago.il.us>
39 * Sridhar Samudrala <sri@us.ibm.com>
40 *
41 * Any bugs reported given to us we will try to fix... any fixes shared will
42 * be incorporated into the next SCTP release.
43 */
44
45#include <linux/slab.h>
46#include <linux/types.h>
47#include <linux/bitmap.h>
48#include <net/sctp/sctp.h>
49#include <net/sctp/sm.h>
50
51static void sctp_tsnmap_update(struct sctp_tsnmap *map);
52static void sctp_tsnmap_find_gap_ack(unsigned long *map, __u16 off,
53 __u16 len, __u16 *start, __u16 *end);
54static int sctp_tsnmap_grow(struct sctp_tsnmap *map, u16 gap);
55
56/* Initialize a block of memory as a tsnmap. */
57struct sctp_tsnmap *sctp_tsnmap_init(struct sctp_tsnmap *map, __u16 len,
58 __u32 initial_tsn, gfp_t gfp)
59{
60 if (!map->tsn_map) {
61 map->tsn_map = kzalloc(len>>3, gfp);
62 if (map->tsn_map == NULL)
63 return NULL;
64
65 map->len = len;
66 } else {
67 bitmap_zero(map->tsn_map, map->len);
68 }
69
70 /* Keep track of TSNs represented by tsn_map. */
71 map->base_tsn = initial_tsn;
72 map->cumulative_tsn_ack_point = initial_tsn - 1;
73 map->max_tsn_seen = map->cumulative_tsn_ack_point;
74 map->num_dup_tsns = 0;
75
76 return map;
77}
78
79void sctp_tsnmap_free(struct sctp_tsnmap *map)
80{
81 map->len = 0;
82 kfree(map->tsn_map);
83}
84
85/* Test the tracking state of this TSN.
86 * Returns:
87 * 0 if the TSN has not yet been seen
88 * >0 if the TSN has been seen (duplicate)
89 * <0 if the TSN is invalid (too large to track)
90 */
91int sctp_tsnmap_check(const struct sctp_tsnmap *map, __u32 tsn)
92{
93 u32 gap;
94
95 /* Check to see if this is an old TSN */
96 if (TSN_lte(tsn, map->cumulative_tsn_ack_point))
97 return 1;
98
99 /* Verify that we can hold this TSN and that it will not
100 * overlfow our map
101 */
102 if (!TSN_lt(tsn, map->base_tsn + SCTP_TSN_MAP_SIZE))
103 return -1;
104
105 /* Calculate the index into the mapping arrays. */
106 gap = tsn - map->base_tsn;
107
108 /* Check to see if TSN has already been recorded. */
109 if (gap < map->len && test_bit(gap, map->tsn_map))
110 return 1;
111 else
112 return 0;
113}
114
115
116/* Mark this TSN as seen. */
117int sctp_tsnmap_mark(struct sctp_tsnmap *map, __u32 tsn,
118 struct sctp_transport *trans)
119{
120 u16 gap;
121
122 if (TSN_lt(tsn, map->base_tsn))
123 return 0;
124
125 gap = tsn - map->base_tsn;
126
127 if (gap >= map->len && !sctp_tsnmap_grow(map, gap))
128 return -ENOMEM;
129
130 if (!sctp_tsnmap_has_gap(map) && gap == 0) {
131 /* In this case the map has no gaps and the tsn we are
132 * recording is the next expected tsn. We don't touch
133 * the map but simply bump the values.
134 */
135 map->max_tsn_seen++;
136 map->cumulative_tsn_ack_point++;
137 if (trans)
138 trans->sack_generation =
139 trans->asoc->peer.sack_generation;
140 map->base_tsn++;
141 } else {
142 /* Either we already have a gap, or about to record a gap, so
143 * have work to do.
144 *
145 * Bump the max.
146 */
147 if (TSN_lt(map->max_tsn_seen, tsn))
148 map->max_tsn_seen = tsn;
149
150 /* Mark the TSN as received. */
151 set_bit(gap, map->tsn_map);
152
153 /* Go fixup any internal TSN mapping variables including
154 * cumulative_tsn_ack_point.
155 */
156 sctp_tsnmap_update(map);
157 }
158
159 return 0;
160}
161
162
163/* Initialize a Gap Ack Block iterator from memory being provided. */
164SCTP_STATIC void sctp_tsnmap_iter_init(const struct sctp_tsnmap *map,
165 struct sctp_tsnmap_iter *iter)
166{
167 /* Only start looking one past the Cumulative TSN Ack Point. */
168 iter->start = map->cumulative_tsn_ack_point + 1;
169}
170
171/* Get the next Gap Ack Blocks. Returns 0 if there was not another block
172 * to get.
173 */
174SCTP_STATIC int sctp_tsnmap_next_gap_ack(const struct sctp_tsnmap *map,
175 struct sctp_tsnmap_iter *iter,
176 __u16 *start, __u16 *end)
177{
178 int ended = 0;
179 __u16 start_ = 0, end_ = 0, offset;
180
181 /* If there are no more gap acks possible, get out fast. */
182 if (TSN_lte(map->max_tsn_seen, iter->start))
183 return 0;
184
185 offset = iter->start - map->base_tsn;
186 sctp_tsnmap_find_gap_ack(map->tsn_map, offset, map->len,
187 &start_, &end_);
188
189 /* The Gap Ack Block happens to end at the end of the map. */
190 if (start_ && !end_)
191 end_ = map->len - 1;
192
193 /* If we found a Gap Ack Block, return the start and end and
194 * bump the iterator forward.
195 */
196 if (end_) {
197 /* Fix up the start and end based on the
198 * Cumulative TSN Ack which is always 1 behind base.
199 */
200 *start = start_ + 1;
201 *end = end_ + 1;
202
203 /* Move the iterator forward. */
204 iter->start = map->cumulative_tsn_ack_point + *end + 1;
205 ended = 1;
206 }
207
208 return ended;
209}
210
211/* Mark this and any lower TSN as seen. */
212void sctp_tsnmap_skip(struct sctp_tsnmap *map, __u32 tsn)
213{
214 u32 gap;
215
216 if (TSN_lt(tsn, map->base_tsn))
217 return;
218 if (!TSN_lt(tsn, map->base_tsn + SCTP_TSN_MAP_SIZE))
219 return;
220
221 /* Bump the max. */
222 if (TSN_lt(map->max_tsn_seen, tsn))
223 map->max_tsn_seen = tsn;
224
225 gap = tsn - map->base_tsn + 1;
226
227 map->base_tsn += gap;
228 map->cumulative_tsn_ack_point += gap;
229 if (gap >= map->len) {
230 /* If our gap is larger then the map size, just
231 * zero out the map.
232 */
233 bitmap_zero(map->tsn_map, map->len);
234 } else {
235 /* If the gap is smaller than the map size,
236 * shift the map by 'gap' bits and update further.
237 */
238 bitmap_shift_right(map->tsn_map, map->tsn_map, gap, map->len);
239 sctp_tsnmap_update(map);
240 }
241}
242
243/********************************************************************
244 * 2nd Level Abstractions
245 ********************************************************************/
246
247/* This private helper function updates the tsnmap buffers and
248 * the Cumulative TSN Ack Point.
249 */
250static void sctp_tsnmap_update(struct sctp_tsnmap *map)
251{
252 u16 len;
253 unsigned long zero_bit;
254
255
256 len = map->max_tsn_seen - map->cumulative_tsn_ack_point;
257 zero_bit = find_first_zero_bit(map->tsn_map, len);
258 if (!zero_bit)
259 return; /* The first 0-bit is bit 0. nothing to do */
260
261 map->base_tsn += zero_bit;
262 map->cumulative_tsn_ack_point += zero_bit;
263
264 bitmap_shift_right(map->tsn_map, map->tsn_map, zero_bit, map->len);
265}
266
267/* How many data chunks are we missing from our peer?
268 */
269__u16 sctp_tsnmap_pending(struct sctp_tsnmap *map)
270{
271 __u32 cum_tsn = map->cumulative_tsn_ack_point;
272 __u32 max_tsn = map->max_tsn_seen;
273 __u32 base_tsn = map->base_tsn;
274 __u16 pending_data;
275 u32 gap, i;
276
277 pending_data = max_tsn - cum_tsn;
278 gap = max_tsn - base_tsn;
279
280 if (gap == 0 || gap >= map->len)
281 goto out;
282
283 for (i = 0; i < gap+1; i++) {
284 if (test_bit(i, map->tsn_map))
285 pending_data--;
286 }
287
288out:
289 return pending_data;
290}
291
292/* This is a private helper for finding Gap Ack Blocks. It searches a
293 * single array for the start and end of a Gap Ack Block.
294 *
295 * The flags "started" and "ended" tell is if we found the beginning
296 * or (respectively) the end of a Gap Ack Block.
297 */
298static void sctp_tsnmap_find_gap_ack(unsigned long *map, __u16 off,
299 __u16 len, __u16 *start, __u16 *end)
300{
301 int i = off;
302
303 /* Look through the entire array, but break out
304 * early if we have found the end of the Gap Ack Block.
305 */
306
307 /* Also, stop looking past the maximum TSN seen. */
308
309 /* Look for the start. */
310 i = find_next_bit(map, len, off);
311 if (i < len)
312 *start = i;
313
314 /* Look for the end. */
315 if (*start) {
316 /* We have found the start, let's find the
317 * end. If we find the end, break out.
318 */
319 i = find_next_zero_bit(map, len, i);
320 if (i < len)
321 *end = i - 1;
322 }
323}
324
325/* Renege that we have seen a TSN. */
326void sctp_tsnmap_renege(struct sctp_tsnmap *map, __u32 tsn)
327{
328 u32 gap;
329
330 if (TSN_lt(tsn, map->base_tsn))
331 return;
332 /* Assert: TSN is in range. */
333 if (!TSN_lt(tsn, map->base_tsn + map->len))
334 return;
335
336 gap = tsn - map->base_tsn;
337
338 /* Pretend we never saw the TSN. */
339 clear_bit(gap, map->tsn_map);
340}
341
342/* How many gap ack blocks do we have recorded? */
343__u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map,
344 struct sctp_gap_ack_block *gabs)
345{
346 struct sctp_tsnmap_iter iter;
347 int ngaps = 0;
348
349 /* Refresh the gap ack information. */
350 if (sctp_tsnmap_has_gap(map)) {
351 __u16 start = 0, end = 0;
352 sctp_tsnmap_iter_init(map, &iter);
353 while (sctp_tsnmap_next_gap_ack(map, &iter,
354 &start,
355 &end)) {
356
357 gabs[ngaps].start = htons(start);
358 gabs[ngaps].end = htons(end);
359 ngaps++;
360 if (ngaps >= SCTP_MAX_GABS)
361 break;
362 }
363 }
364 return ngaps;
365}
366
367static int sctp_tsnmap_grow(struct sctp_tsnmap *map, u16 gap)
368{
369 unsigned long *new;
370 unsigned long inc;
371 u16 len;
372
373 if (gap >= SCTP_TSN_MAP_SIZE)
374 return 0;
375
376 inc = ALIGN((gap - map->len),BITS_PER_LONG) + SCTP_TSN_MAP_INCREMENT;
377 len = min_t(u16, map->len + inc, SCTP_TSN_MAP_SIZE);
378
379 new = kzalloc(len>>3, GFP_ATOMIC);
380 if (!new)
381 return 0;
382
383 bitmap_copy(new, map->tsn_map, map->max_tsn_seen - map->base_tsn);
384 kfree(map->tsn_map);
385 map->tsn_map = new;
386 map->len = len;
387
388 return 1;
389}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/* SCTP kernel implementation
3 * (C) Copyright IBM Corp. 2001, 2004
4 * Copyright (c) 1999-2000 Cisco, Inc.
5 * Copyright (c) 1999-2001 Motorola, Inc.
6 * Copyright (c) 2001 Intel Corp.
7 *
8 * This file is part of the SCTP kernel implementation
9 *
10 * These functions manipulate sctp tsn mapping array.
11 *
12 * Please send any bug reports or fixes you make to the
13 * email address(es):
14 * lksctp developers <linux-sctp@vger.kernel.org>
15 *
16 * Written or modified by:
17 * La Monte H.P. Yarroll <piggy@acm.org>
18 * Jon Grimm <jgrimm@us.ibm.com>
19 * Karl Knutson <karl@athena.chicago.il.us>
20 * Sridhar Samudrala <sri@us.ibm.com>
21 */
22
23#include <linux/slab.h>
24#include <linux/types.h>
25#include <linux/bitmap.h>
26#include <net/sctp/sctp.h>
27#include <net/sctp/sm.h>
28
29static void sctp_tsnmap_update(struct sctp_tsnmap *map);
30static void sctp_tsnmap_find_gap_ack(unsigned long *map, __u16 off,
31 __u16 len, __u16 *start, __u16 *end);
32static int sctp_tsnmap_grow(struct sctp_tsnmap *map, u16 size);
33
34/* Initialize a block of memory as a tsnmap. */
35struct sctp_tsnmap *sctp_tsnmap_init(struct sctp_tsnmap *map, __u16 len,
36 __u32 initial_tsn, gfp_t gfp)
37{
38 if (!map->tsn_map) {
39 map->tsn_map = kzalloc(len>>3, gfp);
40 if (map->tsn_map == NULL)
41 return NULL;
42
43 map->len = len;
44 } else {
45 bitmap_zero(map->tsn_map, map->len);
46 }
47
48 /* Keep track of TSNs represented by tsn_map. */
49 map->base_tsn = initial_tsn;
50 map->cumulative_tsn_ack_point = initial_tsn - 1;
51 map->max_tsn_seen = map->cumulative_tsn_ack_point;
52 map->num_dup_tsns = 0;
53
54 return map;
55}
56
57void sctp_tsnmap_free(struct sctp_tsnmap *map)
58{
59 map->len = 0;
60 kfree(map->tsn_map);
61}
62
63/* Test the tracking state of this TSN.
64 * Returns:
65 * 0 if the TSN has not yet been seen
66 * >0 if the TSN has been seen (duplicate)
67 * <0 if the TSN is invalid (too large to track)
68 */
69int sctp_tsnmap_check(const struct sctp_tsnmap *map, __u32 tsn)
70{
71 u32 gap;
72
73 /* Check to see if this is an old TSN */
74 if (TSN_lte(tsn, map->cumulative_tsn_ack_point))
75 return 1;
76
77 /* Verify that we can hold this TSN and that it will not
78 * overlfow our map
79 */
80 if (!TSN_lt(tsn, map->base_tsn + SCTP_TSN_MAP_SIZE))
81 return -1;
82
83 /* Calculate the index into the mapping arrays. */
84 gap = tsn - map->base_tsn;
85
86 /* Check to see if TSN has already been recorded. */
87 if (gap < map->len && test_bit(gap, map->tsn_map))
88 return 1;
89 else
90 return 0;
91}
92
93
94/* Mark this TSN as seen. */
95int sctp_tsnmap_mark(struct sctp_tsnmap *map, __u32 tsn,
96 struct sctp_transport *trans)
97{
98 u16 gap;
99
100 if (TSN_lt(tsn, map->base_tsn))
101 return 0;
102
103 gap = tsn - map->base_tsn;
104
105 if (gap >= map->len && !sctp_tsnmap_grow(map, gap + 1))
106 return -ENOMEM;
107
108 if (!sctp_tsnmap_has_gap(map) && gap == 0) {
109 /* In this case the map has no gaps and the tsn we are
110 * recording is the next expected tsn. We don't touch
111 * the map but simply bump the values.
112 */
113 map->max_tsn_seen++;
114 map->cumulative_tsn_ack_point++;
115 if (trans)
116 trans->sack_generation =
117 trans->asoc->peer.sack_generation;
118 map->base_tsn++;
119 } else {
120 /* Either we already have a gap, or about to record a gap, so
121 * have work to do.
122 *
123 * Bump the max.
124 */
125 if (TSN_lt(map->max_tsn_seen, tsn))
126 map->max_tsn_seen = tsn;
127
128 /* Mark the TSN as received. */
129 set_bit(gap, map->tsn_map);
130
131 /* Go fixup any internal TSN mapping variables including
132 * cumulative_tsn_ack_point.
133 */
134 sctp_tsnmap_update(map);
135 }
136
137 return 0;
138}
139
140
141/* Initialize a Gap Ack Block iterator from memory being provided. */
142static void sctp_tsnmap_iter_init(const struct sctp_tsnmap *map,
143 struct sctp_tsnmap_iter *iter)
144{
145 /* Only start looking one past the Cumulative TSN Ack Point. */
146 iter->start = map->cumulative_tsn_ack_point + 1;
147}
148
149/* Get the next Gap Ack Blocks. Returns 0 if there was not another block
150 * to get.
151 */
152static int sctp_tsnmap_next_gap_ack(const struct sctp_tsnmap *map,
153 struct sctp_tsnmap_iter *iter,
154 __u16 *start, __u16 *end)
155{
156 int ended = 0;
157 __u16 start_ = 0, end_ = 0, offset;
158
159 /* If there are no more gap acks possible, get out fast. */
160 if (TSN_lte(map->max_tsn_seen, iter->start))
161 return 0;
162
163 offset = iter->start - map->base_tsn;
164 sctp_tsnmap_find_gap_ack(map->tsn_map, offset, map->len,
165 &start_, &end_);
166
167 /* The Gap Ack Block happens to end at the end of the map. */
168 if (start_ && !end_)
169 end_ = map->len - 1;
170
171 /* If we found a Gap Ack Block, return the start and end and
172 * bump the iterator forward.
173 */
174 if (end_) {
175 /* Fix up the start and end based on the
176 * Cumulative TSN Ack which is always 1 behind base.
177 */
178 *start = start_ + 1;
179 *end = end_ + 1;
180
181 /* Move the iterator forward. */
182 iter->start = map->cumulative_tsn_ack_point + *end + 1;
183 ended = 1;
184 }
185
186 return ended;
187}
188
189/* Mark this and any lower TSN as seen. */
190void sctp_tsnmap_skip(struct sctp_tsnmap *map, __u32 tsn)
191{
192 u32 gap;
193
194 if (TSN_lt(tsn, map->base_tsn))
195 return;
196 if (!TSN_lt(tsn, map->base_tsn + SCTP_TSN_MAP_SIZE))
197 return;
198
199 /* Bump the max. */
200 if (TSN_lt(map->max_tsn_seen, tsn))
201 map->max_tsn_seen = tsn;
202
203 gap = tsn - map->base_tsn + 1;
204
205 map->base_tsn += gap;
206 map->cumulative_tsn_ack_point += gap;
207 if (gap >= map->len) {
208 /* If our gap is larger then the map size, just
209 * zero out the map.
210 */
211 bitmap_zero(map->tsn_map, map->len);
212 } else {
213 /* If the gap is smaller than the map size,
214 * shift the map by 'gap' bits and update further.
215 */
216 bitmap_shift_right(map->tsn_map, map->tsn_map, gap, map->len);
217 sctp_tsnmap_update(map);
218 }
219}
220
221/********************************************************************
222 * 2nd Level Abstractions
223 ********************************************************************/
224
225/* This private helper function updates the tsnmap buffers and
226 * the Cumulative TSN Ack Point.
227 */
228static void sctp_tsnmap_update(struct sctp_tsnmap *map)
229{
230 u16 len;
231 unsigned long zero_bit;
232
233
234 len = map->max_tsn_seen - map->cumulative_tsn_ack_point;
235 zero_bit = find_first_zero_bit(map->tsn_map, len);
236 if (!zero_bit)
237 return; /* The first 0-bit is bit 0. nothing to do */
238
239 map->base_tsn += zero_bit;
240 map->cumulative_tsn_ack_point += zero_bit;
241
242 bitmap_shift_right(map->tsn_map, map->tsn_map, zero_bit, map->len);
243}
244
245/* How many data chunks are we missing from our peer?
246 */
247__u16 sctp_tsnmap_pending(struct sctp_tsnmap *map)
248{
249 __u32 cum_tsn = map->cumulative_tsn_ack_point;
250 __u32 max_tsn = map->max_tsn_seen;
251 __u32 base_tsn = map->base_tsn;
252 __u16 pending_data;
253 u32 gap;
254
255 pending_data = max_tsn - cum_tsn;
256 gap = max_tsn - base_tsn;
257
258 if (gap == 0 || gap >= map->len)
259 goto out;
260
261 pending_data -= bitmap_weight(map->tsn_map, gap + 1);
262out:
263 return pending_data;
264}
265
266/* This is a private helper for finding Gap Ack Blocks. It searches a
267 * single array for the start and end of a Gap Ack Block.
268 *
269 * The flags "started" and "ended" tell is if we found the beginning
270 * or (respectively) the end of a Gap Ack Block.
271 */
272static void sctp_tsnmap_find_gap_ack(unsigned long *map, __u16 off,
273 __u16 len, __u16 *start, __u16 *end)
274{
275 int i = off;
276
277 /* Look through the entire array, but break out
278 * early if we have found the end of the Gap Ack Block.
279 */
280
281 /* Also, stop looking past the maximum TSN seen. */
282
283 /* Look for the start. */
284 i = find_next_bit(map, len, off);
285 if (i < len)
286 *start = i;
287
288 /* Look for the end. */
289 if (*start) {
290 /* We have found the start, let's find the
291 * end. If we find the end, break out.
292 */
293 i = find_next_zero_bit(map, len, i);
294 if (i < len)
295 *end = i - 1;
296 }
297}
298
299/* Renege that we have seen a TSN. */
300void sctp_tsnmap_renege(struct sctp_tsnmap *map, __u32 tsn)
301{
302 u32 gap;
303
304 if (TSN_lt(tsn, map->base_tsn))
305 return;
306 /* Assert: TSN is in range. */
307 if (!TSN_lt(tsn, map->base_tsn + map->len))
308 return;
309
310 gap = tsn - map->base_tsn;
311
312 /* Pretend we never saw the TSN. */
313 clear_bit(gap, map->tsn_map);
314}
315
316/* How many gap ack blocks do we have recorded? */
317__u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map,
318 struct sctp_gap_ack_block *gabs)
319{
320 struct sctp_tsnmap_iter iter;
321 int ngaps = 0;
322
323 /* Refresh the gap ack information. */
324 if (sctp_tsnmap_has_gap(map)) {
325 __u16 start = 0, end = 0;
326 sctp_tsnmap_iter_init(map, &iter);
327 while (sctp_tsnmap_next_gap_ack(map, &iter,
328 &start,
329 &end)) {
330
331 gabs[ngaps].start = htons(start);
332 gabs[ngaps].end = htons(end);
333 ngaps++;
334 if (ngaps >= SCTP_MAX_GABS)
335 break;
336 }
337 }
338 return ngaps;
339}
340
341static int sctp_tsnmap_grow(struct sctp_tsnmap *map, u16 size)
342{
343 unsigned long *new;
344 unsigned long inc;
345 u16 len;
346
347 if (size > SCTP_TSN_MAP_SIZE)
348 return 0;
349
350 inc = ALIGN((size - map->len), BITS_PER_LONG) + SCTP_TSN_MAP_INCREMENT;
351 len = min_t(u16, map->len + inc, SCTP_TSN_MAP_SIZE);
352
353 new = kzalloc(len>>3, GFP_ATOMIC);
354 if (!new)
355 return 0;
356
357 bitmap_copy(new, map->tsn_map,
358 map->max_tsn_seen - map->cumulative_tsn_ack_point);
359 kfree(map->tsn_map);
360 map->tsn_map = new;
361 map->len = len;
362
363 return 1;
364}