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Diffstat (limited to '')
| -rw-r--r-- | include/net/sctp/tsnmap.h | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/include/net/sctp/tsnmap.h b/include/net/sctp/tsnmap.h new file mode 100644 index 000000000..616ae0d49 --- /dev/null +++ b/include/net/sctp/tsnmap.h @@ -0,0 +1,157 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* 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 implementation + * + * These are the definitions needed for the tsnmap type. The tsnmap is used + * to track out of order TSNs received. + * + * Please send any bug reports or fixes you make to the + * email address(es): + * lksctp developers <linux-sctp@vger.kernel.org> + * + * Written or modified by: + * Jon Grimm <jgrimm@us.ibm.com> + * La Monte H.P. Yarroll <piggy@acm.org> + * Karl Knutson <karl@athena.chicago.il.us> + * Sridhar Samudrala <sri@us.ibm.com> + */ +#include <net/sctp/constants.h> + +#ifndef __sctp_tsnmap_h__ +#define __sctp_tsnmap_h__ + +/* RFC 2960 12.2 Parameters necessary per association (i.e. the TCB) + * Mapping An array of bits or bytes indicating which out of + * Array order TSN's have been received (relative to the + * Last Rcvd TSN). If no gaps exist, i.e. no out of + * order packets have been received, this array + * will be set to all zero. This structure may be + * in the form of a circular buffer or bit array. + */ +struct sctp_tsnmap { + /* This array counts the number of chunks with each TSN. + * It points at one of the two buffers with which we will + * ping-pong between. + */ + unsigned long *tsn_map; + + /* This is the TSN at tsn_map[0]. */ + __u32 base_tsn; + + /* Last Rcvd : This is the last TSN received in + * TSN : sequence. This value is set initially by + * : taking the peer's Initial TSN, received in + * : the INIT or INIT ACK chunk, and subtracting + * : one from it. + * + * Throughout most of the specification this is called the + * "Cumulative TSN ACK Point". In this case, we + * ignore the advice in 12.2 in favour of the term + * used in the bulk of the text. + */ + __u32 cumulative_tsn_ack_point; + + /* This is the highest TSN we've marked. */ + __u32 max_tsn_seen; + + /* This is the minimum number of TSNs we can track. This corresponds + * to the size of tsn_map. Note: the overflow_map allows us to + * potentially track more than this quantity. + */ + __u16 len; + + /* Data chunks pending receipt. used by SCTP_STATUS sockopt */ + __u16 pending_data; + + /* Record duplicate TSNs here. We clear this after + * every SACK. Store up to SCTP_MAX_DUP_TSNS worth of + * information. + */ + __u16 num_dup_tsns; + __be32 dup_tsns[SCTP_MAX_DUP_TSNS]; +}; + +struct sctp_tsnmap_iter { + __u32 start; +}; + +/* Initialize a block of memory as a tsnmap. */ +struct sctp_tsnmap *sctp_tsnmap_init(struct sctp_tsnmap *, __u16 len, + __u32 initial_tsn, gfp_t gfp); + +void sctp_tsnmap_free(struct sctp_tsnmap *map); + +/* Test the tracking state of this TSN. + * Returns: + * 0 if the TSN has not yet been seen + * >0 if the TSN has been seen (duplicate) + * <0 if the TSN is invalid (too large to track) + */ +int sctp_tsnmap_check(const struct sctp_tsnmap *, __u32 tsn); + +/* Mark this TSN as seen. */ +int sctp_tsnmap_mark(struct sctp_tsnmap *, __u32 tsn, + struct sctp_transport *trans); + +/* Mark this TSN and all lower as seen. */ +void sctp_tsnmap_skip(struct sctp_tsnmap *map, __u32 tsn); + +/* Retrieve the Cumulative TSN ACK Point. */ +static inline __u32 sctp_tsnmap_get_ctsn(const struct sctp_tsnmap *map) +{ + return map->cumulative_tsn_ack_point; +} + +/* Retrieve the highest TSN we've seen. */ +static inline __u32 sctp_tsnmap_get_max_tsn_seen(const struct sctp_tsnmap *map) +{ + return map->max_tsn_seen; +} + +/* How many duplicate TSNs are stored? */ +static inline __u16 sctp_tsnmap_num_dups(struct sctp_tsnmap *map) +{ + return map->num_dup_tsns; +} + +/* Return pointer to duplicate tsn array as needed by SACK. */ +static inline __be32 *sctp_tsnmap_get_dups(struct sctp_tsnmap *map) +{ + map->num_dup_tsns = 0; + return map->dup_tsns; +} + +/* How many gap ack blocks do we have recorded? */ +__u16 sctp_tsnmap_num_gabs(struct sctp_tsnmap *map, + struct sctp_gap_ack_block *gabs); + +/* Refresh the count on pending data. */ +__u16 sctp_tsnmap_pending(struct sctp_tsnmap *map); + +/* Is there a gap in the TSN map? */ +static inline int sctp_tsnmap_has_gap(const struct sctp_tsnmap *map) +{ + return map->cumulative_tsn_ack_point != map->max_tsn_seen; +} + +/* Mark a duplicate TSN. Note: limit the storage of duplicate TSN + * information. + */ +static inline void sctp_tsnmap_mark_dup(struct sctp_tsnmap *map, __u32 tsn) +{ + if (map->num_dup_tsns < SCTP_MAX_DUP_TSNS) + map->dup_tsns[map->num_dup_tsns++] = htonl(tsn); +} + +/* Renege a TSN that was seen. */ +void sctp_tsnmap_renege(struct sctp_tsnmap *, __u32 tsn); + +/* Is there a gap in the TSN map? */ +int sctp_tsnmap_has_gap(const struct sctp_tsnmap *); + +#endif /* __sctp_tsnmap_h__ */ |