-/* SCTP kernel reference Implementation
+/* SCTP kernel implementation
* (C) Copyright IBM Corp. 2001, 2004
* Copyright (c) 1999-2000 Cisco, Inc.
* Copyright (c) 1999-2001 Motorola, Inc.
* Copyright (c) 2001 Intel Corp.
*
- * This file is part of the SCTP kernel reference Implementation
+ * This file is part of the SCTP kernel implementation
*
* These functions manipulate sctp tsn mapping array.
*
- * The SCTP reference implementation is free software;
+ * This SCTP implementation is free software;
* you can redistribute it and/or modify it under the terms of
* the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
- * The SCTP reference implementation is distributed in the hope that it
+ * This SCTP implementation is distributed in the hope that it
* will be useful, but WITHOUT ANY WARRANTY; without even the implied
* ************************
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*/
#include <linux/types.h>
+#include <linux/bitmap.h>
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>
static void sctp_tsnmap_update(struct sctp_tsnmap *map);
-static void sctp_tsnmap_find_gap_ack(__u8 *map, __u16 off,
- __u16 len, __u16 base,
- int *started, __u16 *start,
- int *ended, __u16 *end);
+static void sctp_tsnmap_find_gap_ack(unsigned long *map, __u16 off,
+ __u16 len, __u16 *start, __u16 *end);
+static int sctp_tsnmap_grow(struct sctp_tsnmap *map, u16 gap);
/* Initialize a block of memory as a tsnmap. */
struct sctp_tsnmap *sctp_tsnmap_init(struct sctp_tsnmap *map, __u16 len,
- __u32 initial_tsn)
+ __u32 initial_tsn, gfp_t gfp)
{
- map->tsn_map = map->raw_map;
- map->overflow_map = map->tsn_map + len;
- map->len = len;
-
- /* Clear out a TSN ack status. */
- memset(map->tsn_map, 0x00, map->len + map->len);
+ if (!map->tsn_map) {
+ map->tsn_map = kzalloc(len>>3, gfp);
+ if (map->tsn_map == NULL)
+ return NULL;
+
+ map->len = len;
+ } else {
+ bitmap_zero(map->tsn_map, map->len);
+ }
/* Keep track of TSNs represented by tsn_map. */
map->base_tsn = initial_tsn;
- map->overflow_tsn = initial_tsn + map->len;
map->cumulative_tsn_ack_point = initial_tsn - 1;
map->max_tsn_seen = map->cumulative_tsn_ack_point;
- map->malloced = 0;
map->num_dup_tsns = 0;
return map;
}
+void sctp_tsnmap_free(struct sctp_tsnmap *map)
+{
+ map->len = 0;
+ kfree(map->tsn_map);
+}
+
/* Test the tracking state of this TSN.
* Returns:
* 0 if the TSN has not yet been seen
*/
int sctp_tsnmap_check(const struct sctp_tsnmap *map, __u32 tsn)
{
- __s32 gap;
- int dup;
+ u32 gap;
+
+ /* Check to see if this is an old TSN */
+ if (TSN_lte(tsn, map->cumulative_tsn_ack_point))
+ return 1;
+
+ /* Verify that we can hold this TSN and that it will not
+ * overlfow our map
+ */
+ if (!TSN_lt(tsn, map->base_tsn + SCTP_TSN_MAP_SIZE))
+ return -1;
/* Calculate the index into the mapping arrays. */
gap = tsn - map->base_tsn;
- /* Verify that we can hold this TSN. */
- if (gap >= (/* base */ map->len + /* overflow */ map->len)) {
- dup = -1;
- goto out;
- }
-
- /* Honk if we've already seen this TSN.
- * We have three cases:
- * 1. The TSN is ancient or belongs to a previous tsn_map.
- * 2. The TSN is already marked in the tsn_map.
- * 3. The TSN is already marked in the tsn_map_overflow.
- */
- if (gap < 0 ||
- (gap < map->len && map->tsn_map[gap]) ||
- (gap >= map->len && map->overflow_map[gap - map->len]))
- dup = 1;
+ /* Check to see if TSN has already been recorded. */
+ if (gap < map->len && test_bit(gap, map->tsn_map))
+ return 1;
else
- dup = 0;
-
-out:
- return dup;
+ return 0;
}
/* Mark this TSN as seen. */
-void sctp_tsnmap_mark(struct sctp_tsnmap *map, __u32 tsn)
+int sctp_tsnmap_mark(struct sctp_tsnmap *map, __u32 tsn)
{
- __s32 gap;
+ u16 gap;
- /* Vacuously mark any TSN which precedes the map base or
- * exceeds the end of the map.
- */
if (TSN_lt(tsn, map->base_tsn))
- return;
- if (!TSN_lt(tsn, map->base_tsn + map->len + map->len))
- return;
-
- /* Bump the max. */
- if (TSN_lt(map->max_tsn_seen, tsn))
- map->max_tsn_seen = tsn;
+ return 0;
- /* Assert: TSN is in range. */
gap = tsn - map->base_tsn;
- /* Mark the TSN as received. */
- if (gap < map->len)
- map->tsn_map[gap]++;
- else
- map->overflow_map[gap - map->len]++;
+ if (gap >= map->len && !sctp_tsnmap_grow(map, gap))
+ return -ENOMEM;
- /* Go fixup any internal TSN mapping variables including
- * cumulative_tsn_ack_point.
- */
- sctp_tsnmap_update(map);
+ if (!sctp_tsnmap_has_gap(map) && gap == 0) {
+ /* In this case the map has no gaps and the tsn we are
+ * recording is the next expected tsn. We don't touch
+ * the map but simply bump the values.
+ */
+ map->max_tsn_seen++;
+ map->cumulative_tsn_ack_point++;
+ map->base_tsn++;
+ } else {
+ /* Either we already have a gap, or about to record a gap, so
+ * have work to do.
+ *
+ * Bump the max.
+ */
+ if (TSN_lt(map->max_tsn_seen, tsn))
+ map->max_tsn_seen = tsn;
+
+ /* Mark the TSN as received. */
+ set_bit(gap, map->tsn_map);
+
+ /* Go fixup any internal TSN mapping variables including
+ * cumulative_tsn_ack_point.
+ */
+ sctp_tsnmap_update(map);
+ }
+
+ return 0;
}
struct sctp_tsnmap_iter *iter,
__u16 *start, __u16 *end)
{
- int started, ended;
- __u16 _start, _end, offset;
-
- /* We haven't found a gap yet. */
- started = ended = 0;
+ int ended = 0;
+ __u16 start_ = 0, end_ = 0, offset;
/* If there are no more gap acks possible, get out fast. */
if (TSN_lte(map->max_tsn_seen, iter->start))
return 0;
- /* Search the first mapping array. */
- if (iter->start - map->base_tsn < map->len) {
-
- offset = iter->start - map->base_tsn;
- sctp_tsnmap_find_gap_ack(map->tsn_map, offset, map->len, 0,
- &started, &_start, &ended, &_end);
- }
-
- /* Do we need to check the overflow map? */
- if (!ended) {
- /* Fix up where we'd like to start searching in the
- * overflow map.
- */
- if (iter->start - map->base_tsn < map->len)
- offset = 0;
- else
- offset = iter->start - map->base_tsn - map->len;
-
- /* Search the overflow map. */
- sctp_tsnmap_find_gap_ack(map->overflow_map,
- offset,
- map->len,
- map->len,
- &started, &_start,
- &ended, &_end);
- }
+ offset = iter->start - map->base_tsn;
+ sctp_tsnmap_find_gap_ack(map->tsn_map, offset, map->len,
+ &start_, &end_);
- /* The Gap Ack Block happens to end at the end of the
- * overflow map.
- */
- if (started && !ended) {
- ended++;
- _end = map->len + map->len - 1;
- }
+ /* The Gap Ack Block happens to end at the end of the map. */
+ if (start_ && !end_)
+ end_ = map->len - 1;
/* If we found a Gap Ack Block, return the start and end and
* bump the iterator forward.
*/
- if (ended) {
+ if (end_) {
/* Fix up the start and end based on the
- * Cumulative TSN Ack offset into the map.
+ * Cumulative TSN Ack which is always 1 behind base.
*/
- int gap = map->cumulative_tsn_ack_point -
- map->base_tsn;
-
- *start = _start - gap;
- *end = _end - gap;
+ *start = start_ + 1;
+ *end = end_ + 1;
/* Move the iterator forward. */
iter->start = map->cumulative_tsn_ack_point + *end + 1;
+ ended = 1;
}
return ended;
/* Mark this and any lower TSN as seen. */
void sctp_tsnmap_skip(struct sctp_tsnmap *map, __u32 tsn)
{
- __s32 gap;
+ u32 gap;
- /* Vacuously mark any TSN which precedes the map base or
- * exceeds the end of the map.
- */
if (TSN_lt(tsn, map->base_tsn))
return;
- if (!TSN_lt(tsn, map->base_tsn + map->len + map->len))
+ if (!TSN_lt(tsn, map->base_tsn + SCTP_TSN_MAP_SIZE))
return;
/* Bump the max. */
if (TSN_lt(map->max_tsn_seen, tsn))
map->max_tsn_seen = tsn;
- /* Assert: TSN is in range. */
gap = tsn - map->base_tsn + 1;
- /* Mark the TSNs as received. */
- if (gap <= map->len)
- memset(map->tsn_map, 0x01, gap);
- else {
- memset(map->tsn_map, 0x01, map->len);
- memset(map->overflow_map, 0x01, (gap - map->len));
+ map->base_tsn += gap;
+ map->cumulative_tsn_ack_point += gap;
+ if (gap >= map->len) {
+ /* If our gap is larger then the map size, just
+ * zero out the map.
+ */
+ bitmap_zero(map->tsn_map, map->len);
+ } else {
+ /* If the gap is smaller than the map size,
+ * shift the map by 'gap' bits and update further.
+ */
+ bitmap_shift_right(map->tsn_map, map->tsn_map, gap, map->len);
+ sctp_tsnmap_update(map);
}
-
- /* Go fixup any internal TSN mapping variables including
- * cumulative_tsn_ack_point.
- */
- sctp_tsnmap_update(map);
}
/********************************************************************
*/
static void sctp_tsnmap_update(struct sctp_tsnmap *map)
{
- __u32 ctsn;
-
- ctsn = map->cumulative_tsn_ack_point;
- do {
- ctsn++;
- if (ctsn == map->overflow_tsn) {
- /* Now tsn_map must have been all '1's,
- * so we swap the map and check the overflow table
- */
- __u8 *tmp = map->tsn_map;
- memset(tmp, 0, map->len);
- map->tsn_map = map->overflow_map;
- map->overflow_map = tmp;
-
- /* Update the tsn_map boundaries. */
- map->base_tsn += map->len;
- map->overflow_tsn += map->len;
- }
- } while (map->tsn_map[ctsn - map->base_tsn]);
+ u16 len;
+ unsigned long zero_bit;
+
+
+ len = map->max_tsn_seen - map->cumulative_tsn_ack_point;
+ zero_bit = find_first_zero_bit(map->tsn_map, len);
+ if (!zero_bit)
+ return; /* The first 0-bit is bit 0. nothing to do */
+
+ map->base_tsn += zero_bit;
+ map->cumulative_tsn_ack_point += zero_bit;
- map->cumulative_tsn_ack_point = ctsn - 1; /* Back up one. */
+ bitmap_shift_right(map->tsn_map, map->tsn_map, zero_bit, map->len);
}
/* How many data chunks are we missing from our peer?
__u32 max_tsn = map->max_tsn_seen;
__u32 base_tsn = map->base_tsn;
__u16 pending_data;
- __s32 gap, start, end, i;
+ u32 gap, i;
pending_data = max_tsn - cum_tsn;
gap = max_tsn - base_tsn;
- if (gap <= 0 || gap >= (map->len + map->len))
+ if (gap == 0 || gap >= map->len)
goto out;
- start = ((cum_tsn >= base_tsn) ? (cum_tsn - base_tsn + 1) : 0);
- end = ((gap > map->len ) ? map->len : gap + 1);
-
- for (i = start; i < end; i++) {
- if (map->tsn_map[i])
+ for (i = 0; i < gap+1; i++) {
+ if (test_bit(i, map->tsn_map))
pending_data--;
}
- if (gap >= map->len) {
- start = 0;
- end = gap - map->len + 1;
- for (i = start; i < end; i++) {
- if (map->overflow_map[i])
- pending_data--;
- }
- }
-
out:
return pending_data;
}
* The flags "started" and "ended" tell is if we found the beginning
* or (respectively) the end of a Gap Ack Block.
*/
-static void sctp_tsnmap_find_gap_ack(__u8 *map, __u16 off,
- __u16 len, __u16 base,
- int *started, __u16 *start,
- int *ended, __u16 *end)
+static void sctp_tsnmap_find_gap_ack(unsigned long *map, __u16 off,
+ __u16 len, __u16 *start, __u16 *end)
{
int i = off;
/* Also, stop looking past the maximum TSN seen. */
/* Look for the start. */
- if (!(*started)) {
- for (; i < len; i++) {
- if (map[i]) {
- (*started)++;
- *start = base + i;
- break;
- }
- }
- }
+ i = find_next_bit(map, len, off);
+ if (i < len)
+ *start = i;
/* Look for the end. */
- if (*started) {
+ if (*start) {
/* We have found the start, let's find the
* end. If we find the end, break out.
*/
- for (; i < len; i++) {
- if (!map[i]) {
- (*ended)++;
- *end = base + i - 1;
- break;
- }
- }
+ i = find_next_zero_bit(map, len, i);
+ if (i < len)
+ *end = i - 1;
}
}
/* Renege that we have seen a TSN. */
void sctp_tsnmap_renege(struct sctp_tsnmap *map, __u32 tsn)
{
- __s32 gap;
+ u32 gap;
if (TSN_lt(tsn, map->base_tsn))
return;
- if (!TSN_lt(tsn, map->base_tsn + map->len + map->len))
+ /* Assert: TSN is in range. */
+ if (!TSN_lt(tsn, map->base_tsn + map->len))
return;
- /* Assert: TSN is in range. */
gap = tsn - map->base_tsn;
/* Pretend we never saw the TSN. */
- if (gap < map->len)
- map->tsn_map[gap] = 0;
- else
- map->overflow_map[gap - map->len] = 0;
+ clear_bit(gap, map->tsn_map);
}
/* How many gap ack blocks do we have recorded? */
-__u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map)
+__u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map,
+ struct sctp_gap_ack_block *gabs)
{
struct sctp_tsnmap_iter iter;
- int gabs = 0;
+ int ngaps = 0;
/* Refresh the gap ack information. */
if (sctp_tsnmap_has_gap(map)) {
&start,
&end)) {
- map->gabs[gabs].start = htons(start);
- map->gabs[gabs].end = htons(end);
- gabs++;
- if (gabs >= SCTP_MAX_GABS)
+ gabs[ngaps].start = htons(start);
+ gabs[ngaps].end = htons(end);
+ ngaps++;
+ if (ngaps >= SCTP_MAX_GABS)
break;
}
}
- return gabs;
+ return ngaps;
+}
+
+static int sctp_tsnmap_grow(struct sctp_tsnmap *map, u16 gap)
+{
+ unsigned long *new;
+ unsigned long inc;
+ u16 len;
+
+ if (gap >= SCTP_TSN_MAP_SIZE)
+ return 0;
+
+ inc = ALIGN((gap - map->len),BITS_PER_LONG) + SCTP_TSN_MAP_INCREMENT;
+ len = min_t(u16, map->len + inc, SCTP_TSN_MAP_SIZE);
+
+ new = kzalloc(len>>3, GFP_ATOMIC);
+ if (!new)
+ return 0;
+
+ bitmap_copy(new, map->tsn_map, map->max_tsn_seen - map->base_tsn);
+ kfree(map->tsn_map);
+ map->tsn_map = new;
+ map->len = len;
+
+ return 1;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff