diff options
Diffstat (limited to 'net/sctp/tsnmap.c')
-rw-r--r-- | net/sctp/tsnmap.c | 331 |
1 files changed, 148 insertions, 183 deletions
diff --git a/net/sctp/tsnmap.c b/net/sctp/tsnmap.c index f3e58b275905..142ed7ca424d 100644 --- a/net/sctp/tsnmap.c +++ b/net/sctp/tsnmap.c @@ -43,37 +43,44 @@ */ #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 @@ -82,66 +89,69 @@ struct sctp_tsnmap *sctp_tsnmap_init(struct sctp_tsnmap *map, __u16 len, */ 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; } @@ -160,66 +170,34 @@ SCTP_STATIC int sctp_tsnmap_next_gap_ack(const struct sctp_tsnmap *map, 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; @@ -228,35 +206,33 @@ SCTP_STATIC int sctp_tsnmap_next_gap_ack(const struct sctp_tsnmap *map, /* 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 then 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); } /******************************************************************** @@ -268,27 +244,19 @@ void sctp_tsnmap_skip(struct sctp_tsnmap *map, __u32 tsn) */ 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? @@ -299,31 +267,19 @@ __u16 sctp_tsnmap_pending(struct sctp_tsnmap *map) __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; } @@ -334,10 +290,8 @@ out: * 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; @@ -348,49 +302,36 @@ static void sctp_tsnmap_find_gap_ack(__u8 *map, __u16 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? */ @@ -416,3 +357,27 @@ __u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map) } return gabs; } + +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; +} |