^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 _DCCP_FEAT_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) #define _DCCP_FEAT_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * net/dccp/feat.h
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * Feature negotiation for the DCCP protocol (RFC 4340, section 6)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * Copyright (c) 2008 Gerrit Renker <gerrit@erg.abdn.ac.uk>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * Copyright (c) 2005 Andrea Bittau <a.bittau@cs.ucl.ac.uk>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include "dccp.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) * Known limit values
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) /* Ack Ratio takes 2-byte integer values (11.3) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #define DCCPF_ACK_RATIO_MAX 0xFFFF
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) /* Wmin=32 and Wmax=2^46-1 from 7.5.2 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #define DCCPF_SEQ_WMIN 32
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #define DCCPF_SEQ_WMAX 0x3FFFFFFFFFFFull
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) /* Maximum number of SP values that fit in a single (Confirm) option */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #define DCCP_FEAT_MAX_SP_VALS (DCCP_SINGLE_OPT_MAXLEN - 2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) enum dccp_feat_type {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) FEAT_AT_RX = 1, /* located at RX side of half-connection */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) FEAT_AT_TX = 2, /* located at TX side of half-connection */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) FEAT_SP = 4, /* server-priority reconciliation (6.3.1) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) FEAT_NN = 8, /* non-negotiable reconciliation (6.3.2) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) FEAT_UNKNOWN = 0xFF /* not understood or invalid feature */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) enum dccp_feat_state {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) FEAT_DEFAULT = 0, /* using default values from 6.4 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) FEAT_INITIALISING, /* feature is being initialised */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) FEAT_CHANGING, /* Change sent but not confirmed yet */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) FEAT_UNSTABLE, /* local modification in state CHANGING */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) FEAT_STABLE /* both ends (think they) agree */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) * dccp_feat_val - Container for SP or NN feature values
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) * @nn: single NN value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) * @sp.vec: single SP value plus optional preference list
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) * @sp.len: length of @sp.vec in bytes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) typedef union {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) u64 nn;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) struct {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) u8 *vec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) u8 len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) } sp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) } dccp_feat_val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) * struct feat_entry - Data structure to perform feature negotiation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) * @val: feature's current value (SP features may have preference list)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) * @state: feature's current state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) * @feat_num: one of %dccp_feature_numbers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) * @needs_mandatory: whether Mandatory options should be sent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) * @needs_confirm: whether to send a Confirm instead of a Change
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) * @empty_confirm: whether to send an empty Confirm (depends on @needs_confirm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) * @is_local: feature location (1) or feature-remote (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) * @node: list pointers, entries arranged in FIFO order
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) struct dccp_feat_entry {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) dccp_feat_val val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) enum dccp_feat_state state:8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) u8 feat_num;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) bool needs_mandatory,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) needs_confirm,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) empty_confirm,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) is_local;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) struct list_head node;
^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) static inline u8 dccp_feat_genopt(struct dccp_feat_entry *entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) if (entry->needs_confirm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) return entry->is_local ? DCCPO_CONFIRM_L : DCCPO_CONFIRM_R;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) return entry->is_local ? DCCPO_CHANGE_L : DCCPO_CHANGE_R;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) * struct ccid_dependency - Track changes resulting from choosing a CCID
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) * @dependent_feat: one of %dccp_feature_numbers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) * @is_local: local (1) or remote (0) @dependent_feat
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) * @is_mandatory: whether presence of @dependent_feat is mission-critical or not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) * @val: corresponding default value for @dependent_feat (u8 is sufficient here)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) struct ccid_dependency {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) u8 dependent_feat;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) bool is_local:1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) is_mandatory:1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) u8 val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) * Sysctls to seed defaults for feature negotiation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) extern unsigned long sysctl_dccp_sequence_window;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) extern int sysctl_dccp_rx_ccid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) extern int sysctl_dccp_tx_ccid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) int dccp_feat_init(struct sock *sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) void dccp_feat_initialise_sysctls(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) int dccp_feat_register_sp(struct sock *sk, u8 feat, u8 is_local,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) u8 const *list, u8 len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) int dccp_feat_parse_options(struct sock *, struct dccp_request_sock *,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) u8 mand, u8 opt, u8 feat, u8 *val, u8 len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) int dccp_feat_clone_list(struct list_head const *, struct list_head *);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) * Encoding variable-length options and their maximum length.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) * This affects NN options (SP options are all u8) and other variable-length
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) * options (see table 3 in RFC 4340). The limit is currently given the Sequence
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) * Window NN value (sec. 7.5.2) and the NDP count (sec. 7.7) option, all other
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) * options consume less than 6 bytes (timestamps are 4 bytes).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) * When updating this constant (e.g. due to new internet drafts / RFCs), make
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) * sure that you also update all code which refers to it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) #define DCCP_OPTVAL_MAXLEN 6
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) void dccp_encode_value_var(const u64 value, u8 *to, const u8 len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) u64 dccp_decode_value_var(const u8 *bf, const u8 len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) u64 dccp_feat_nn_get(struct sock *sk, u8 feat);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) int dccp_insert_option_mandatory(struct sk_buff *skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat, u8 *val, u8 len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) bool repeat_first);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) #endif /* _DCCP_FEAT_H */
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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