net/sctp/tsnmap.c

29 static void sctp_tsnmap_update(struct sctp_tsnmap *map);
30 static void sctp_tsnmap_find_gap_ack(unsigned long *map, __u16 off,
32 static int sctp_tsnmap_grow(struct sctp_tsnmap *map, u16 size);
35 struct sctp_tsnmap *sctp_tsnmap_init(struct sctp_tsnmap *map, __u16 len,
38 	if (!map->tsn_map) {
39 		map->tsn_map = kzalloc(len>>3, gfp);
40 		if (map->tsn_map == NULL)
43 		map->len = len;
45 		bitmap_zero(map->tsn_map, map->len);
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;
54 	return map;
57 void sctp_tsnmap_free(struct sctp_tsnmap *map)
59 	map->len = 0;
60 	kfree(map->tsn_map);
69 int sctp_tsnmap_check(const struct sctp_tsnmap *map, __u32 tsn)
74 	if (TSN_lte(tsn, map->cumulative_tsn_ack_point))
78 	 * overflow our map
80 	if (!TSN_lt(tsn, map->base_tsn + SCTP_TSN_MAP_SIZE))
84 	gap = tsn - map->base_tsn;
87 	if (gap < map->len && test_bit(gap, map->tsn_map))
95 int sctp_tsnmap_mark(struct sctp_tsnmap *map, __u32 tsn,
100 	if (TSN_lt(tsn, map->base_tsn))
103 	gap = tsn - map->base_tsn;
105 	if (gap >= map->len && !sctp_tsnmap_grow(map, gap + 1))
108 	if (!sctp_tsnmap_has_gap(map) && gap == 0) {
109 		/* In this case the map has no gaps and the tsn we are
111 		 * the map but simply bump the values.
113 		map->max_tsn_seen++;
114 		map->cumulative_tsn_ack_point++;
118 		map->base_tsn++;
125 		if (TSN_lt(map->max_tsn_seen, tsn))
126 			map->max_tsn_seen = tsn;
129 		set_bit(gap, map->tsn_map);
134 		sctp_tsnmap_update(map);
142 static void sctp_tsnmap_iter_init(const struct sctp_tsnmap *map,
146 	iter->start = map->cumulative_tsn_ack_point + 1;
152 static int sctp_tsnmap_next_gap_ack(const struct sctp_tsnmap *map,
160 	if (TSN_lte(map->max_tsn_seen, iter->start))
163 	offset = iter->start - map->base_tsn;
164 	sctp_tsnmap_find_gap_ack(map->tsn_map, offset, map->len,
167 	/* The Gap Ack Block happens to end at the end of the map. */
169 		end_ = map->len - 1;
182 		iter->start = map->cumulative_tsn_ack_point + *end + 1;
190 void sctp_tsnmap_skip(struct sctp_tsnmap *map, __u32 tsn)
194 	if (TSN_lt(tsn, map->base_tsn))
196 	if (!TSN_lt(tsn, map->base_tsn + SCTP_TSN_MAP_SIZE))
200 	if (TSN_lt(map->max_tsn_seen, tsn))
201 		map->max_tsn_seen = tsn;
203 	gap = tsn - map->base_tsn + 1;
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.
211 		bitmap_zero(map->tsn_map, map->len);
213 		/* If the gap is smaller than the map size,
214 		 * shift the map by 'gap' bits and update further.
216 		bitmap_shift_right(map->tsn_map, map->tsn_map, gap, map->len);
217 		sctp_tsnmap_update(map);
228 static void sctp_tsnmap_update(struct sctp_tsnmap *map)
234 	len = map->max_tsn_seen - map->cumulative_tsn_ack_point;
235 	zero_bit = find_first_zero_bit(map->tsn_map, len);
239 	map->base_tsn += zero_bit;
240 	map->cumulative_tsn_ack_point += zero_bit;
242 	bitmap_shift_right(map->tsn_map, map->tsn_map, zero_bit, map->len);
247 __u16 sctp_tsnmap_pending(struct sctp_tsnmap *map)
249 	__u32 cum_tsn = map->cumulative_tsn_ack_point;
250 	__u32 max_tsn = map->max_tsn_seen;
251 	__u32 base_tsn = map->base_tsn;
258 	if (gap == 0 || gap >= map->len)
261 	pending_data -= bitmap_weight(map->tsn_map, gap + 1);
272 static void sctp_tsnmap_find_gap_ack(unsigned long *map, __u16 off,
284 	i = find_next_bit(map, len, off);
293 		i = find_next_zero_bit(map, len, i);
300 void sctp_tsnmap_renege(struct sctp_tsnmap *map, __u32 tsn)
304 	if (TSN_lt(tsn, map->base_tsn))
307 	if (!TSN_lt(tsn, map->base_tsn + map->len))
310 	gap = tsn - map->base_tsn;
313 	clear_bit(gap, map->tsn_map);
317 __u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map,
324 	if (sctp_tsnmap_has_gap(map)) {
326 		sctp_tsnmap_iter_init(map, &iter);
327 		while (sctp_tsnmap_next_gap_ack(map, &iter,
341 static int sctp_tsnmap_grow(struct sctp_tsnmap *map, u16 size)
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);
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;