^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /* SPDX-License-Identifier: GPL-2.0-only */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) #ifndef _ACKVEC_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) #define _ACKVEC_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * net/dccp/ackvec.h
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * An implementation of Ack Vectors for the DCCP protocol
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * Copyright (c) 2007 University of Aberdeen, Scotland, UK
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@mandriva.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/dccp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/compiler.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/list.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) * Ack Vector buffer space is static, in multiples of %DCCP_SINGLE_OPT_MAXLEN,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) * the maximum size of a single Ack Vector. Setting %DCCPAV_NUM_ACKVECS to 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) * will be sufficient for most cases of low Ack Ratios, using a value of 2 gives
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) * more headroom if Ack Ratio is higher or when the sender acknowledges slowly.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) * The maximum value is bounded by the u16 types for indices and functions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #define DCCPAV_NUM_ACKVECS 2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #define DCCPAV_MAX_ACKVEC_LEN (DCCP_SINGLE_OPT_MAXLEN * DCCPAV_NUM_ACKVECS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) /* Estimated minimum average Ack Vector length - used for updating MPS */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #define DCCPAV_MIN_OPTLEN 16
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) /* Threshold for coping with large bursts of losses */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) #define DCCPAV_BURST_THRESH (DCCPAV_MAX_ACKVEC_LEN / 8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) enum dccp_ackvec_states {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) DCCPAV_RECEIVED = 0x00,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) DCCPAV_ECN_MARKED = 0x40,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) DCCPAV_RESERVED = 0x80,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) DCCPAV_NOT_RECEIVED = 0xC0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) #define DCCPAV_MAX_RUNLEN 0x3F
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) static inline u8 dccp_ackvec_runlen(const u8 *cell)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) return *cell & DCCPAV_MAX_RUNLEN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) static inline u8 dccp_ackvec_state(const u8 *cell)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) return *cell & ~DCCPAV_MAX_RUNLEN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) * struct dccp_ackvec - Ack Vector main data structure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) * This implements a fixed-size circular buffer within an array and is largely
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) * based on Appendix A of RFC 4340.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) * @av_buf: circular buffer storage area
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) * @av_buf_head: head index; begin of live portion in @av_buf
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) * @av_buf_tail: tail index; first index _after_ the live portion in @av_buf
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) * @av_buf_ackno: highest seqno of acknowledgeable packet recorded in @av_buf
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) * @av_tail_ackno: lowest seqno of acknowledgeable packet recorded in @av_buf
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) * @av_buf_nonce: ECN nonce sums, each covering subsequent segments of up to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) * %DCCP_SINGLE_OPT_MAXLEN cells in the live portion of @av_buf
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) * @av_overflow: if 1 then buf_head == buf_tail indicates buffer wraparound
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) * @av_records: list of %dccp_ackvec_record (Ack Vectors sent previously)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) struct dccp_ackvec {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) u8 av_buf[DCCPAV_MAX_ACKVEC_LEN];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) u16 av_buf_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) u16 av_buf_tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) u64 av_buf_ackno:48;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) u64 av_tail_ackno:48;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) bool av_buf_nonce[DCCPAV_NUM_ACKVECS];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) u8 av_overflow:1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) struct list_head av_records;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) * struct dccp_ackvec_record - Records information about sent Ack Vectors
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) * These list entries define the additional information which the HC-Receiver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) * keeps about recently-sent Ack Vectors; again refer to RFC 4340, Appendix A.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) * @avr_node: the list node in @av_records
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) * @avr_ack_seqno: sequence number of the packet the Ack Vector was sent on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) * @avr_ack_ackno: the Ack number that this record/Ack Vector refers to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) * @avr_ack_ptr: pointer into @av_buf where this record starts
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) * @avr_ack_runlen: run length of @avr_ack_ptr at the time of sending
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) * @avr_ack_nonce: the sum of @av_buf_nonce's at the time this record was sent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) * The list as a whole is sorted in descending order by @avr_ack_seqno.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) struct dccp_ackvec_record {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) struct list_head avr_node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) u64 avr_ack_seqno:48;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) u64 avr_ack_ackno:48;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) u16 avr_ack_ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) u8 avr_ack_runlen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) u8 avr_ack_nonce:1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) int dccp_ackvec_init(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) void dccp_ackvec_exit(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) void dccp_ackvec_free(struct dccp_ackvec *av);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) void dccp_ackvec_input(struct dccp_ackvec *av, struct sk_buff *skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) int dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seq, u8 sum);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) void dccp_ackvec_clear_state(struct dccp_ackvec *av, const u64 ackno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) u16 dccp_ackvec_buflen(const struct dccp_ackvec *av);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) static inline bool dccp_ackvec_is_empty(const struct dccp_ackvec *av)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) return av->av_overflow == 0 && av->av_buf_head == av->av_buf_tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) * struct dccp_ackvec_parsed - Record offsets of Ack Vectors in skb
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) * @vec: start of vector (offset into skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) * @len: length of @vec
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) * @nonce: whether @vec had an ECN nonce of 0 or 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) * @node: FIFO - arranged in descending order of ack_ackno
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) * This structure is used by CCIDs to access Ack Vectors in a received skb.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) struct dccp_ackvec_parsed {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) u8 *vec,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) nonce:1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) struct list_head node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) int dccp_ackvec_parsed_add(struct list_head *head, u8 *vec, u8 len, u8 nonce);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) void dccp_ackvec_parsed_cleanup(struct list_head *parsed_chunks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) #endif /* _ACKVEC_H */
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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