cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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feat.h (4520B)

      1/* SPDX-License-Identifier: GPL-2.0-only */
      2#ifndef _DCCP_FEAT_H
      3#define _DCCP_FEAT_H
      4/*
      5 *  net/dccp/feat.h
      6 *
      7 *  Feature negotiation for the DCCP protocol (RFC 4340, section 6)
      8 *  Copyright (c) 2008 Gerrit Renker <gerrit@erg.abdn.ac.uk>
      9 *  Copyright (c) 2005 Andrea Bittau <a.bittau@cs.ucl.ac.uk>
     10 */
     11#include <linux/types.h>
     12#include "dccp.h"
     13
     14/*
     15 * Known limit values
     16 */
     17/* Ack Ratio takes 2-byte integer values (11.3) */
     18#define DCCPF_ACK_RATIO_MAX	0xFFFF
     19/* Wmin=32 and Wmax=2^46-1 from 7.5.2 */
     20#define DCCPF_SEQ_WMIN		32
     21#define DCCPF_SEQ_WMAX		0x3FFFFFFFFFFFull
     22/* Maximum number of SP values that fit in a single (Confirm) option */
     23#define DCCP_FEAT_MAX_SP_VALS	(DCCP_SINGLE_OPT_MAXLEN - 2)
     24
     25enum dccp_feat_type {
     26	FEAT_AT_RX   = 1,	/* located at RX side of half-connection  */
     27	FEAT_AT_TX   = 2,	/* located at TX side of half-connection  */
     28	FEAT_SP      = 4,	/* server-priority reconciliation (6.3.1) */
     29	FEAT_NN	     = 8,	/* non-negotiable reconciliation (6.3.2)  */
     30	FEAT_UNKNOWN = 0xFF	/* not understood or invalid feature	  */
     31};
     32
     33enum dccp_feat_state {
     34	FEAT_DEFAULT = 0,	/* using default values from 6.4 */
     35	FEAT_INITIALISING,	/* feature is being initialised  */
     36	FEAT_CHANGING,		/* Change sent but not confirmed yet */
     37	FEAT_UNSTABLE,		/* local modification in state CHANGING */
     38	FEAT_STABLE		/* both ends (think they) agree */
     39};
     40
     41/**
     42 * dccp_feat_val  -  Container for SP or NN feature values
     43 * @nn:     single NN value
     44 * @sp.vec: single SP value plus optional preference list
     45 * @sp.len: length of @sp.vec in bytes
     46 */
     47typedef union {
     48	u64 nn;
     49	struct {
     50		u8	*vec;
     51		u8	len;
     52	}   sp;
     53} dccp_feat_val;
     54
     55/**
     56 * struct feat_entry  -  Data structure to perform feature negotiation
     57 * @val: feature's current value (SP features may have preference list)
     58 * @state: feature's current state
     59 * @feat_num: one of %dccp_feature_numbers
     60 * @needs_mandatory: whether Mandatory options should be sent
     61 * @needs_confirm: whether to send a Confirm instead of a Change
     62 * @empty_confirm: whether to send an empty Confirm (depends on @needs_confirm)
     63 * @is_local: feature location (1) or feature-remote (0)
     64 * @node: list pointers, entries arranged in FIFO order
     65 */
     66struct dccp_feat_entry {
     67	dccp_feat_val           val;
     68	enum dccp_feat_state    state:8;
     69	u8                      feat_num;
     70
     71	bool			needs_mandatory,
     72				needs_confirm,
     73				empty_confirm,
     74				is_local;
     75
     76	struct list_head	node;
     77};
     78
     79static inline u8 dccp_feat_genopt(struct dccp_feat_entry *entry)
     80{
     81	if (entry->needs_confirm)
     82		return entry->is_local ? DCCPO_CONFIRM_L : DCCPO_CONFIRM_R;
     83	return entry->is_local ? DCCPO_CHANGE_L : DCCPO_CHANGE_R;
     84}
     85
     86/**
     87 * struct ccid_dependency  -  Track changes resulting from choosing a CCID
     88 * @dependent_feat: one of %dccp_feature_numbers
     89 * @is_local: local (1) or remote (0) @dependent_feat
     90 * @is_mandatory: whether presence of @dependent_feat is mission-critical or not
     91 * @val: corresponding default value for @dependent_feat (u8 is sufficient here)
     92 */
     93struct ccid_dependency {
     94	u8	dependent_feat;
     95	bool	is_local:1,
     96		is_mandatory:1;
     97	u8	val;
     98};
     99
    100/*
    101 * Sysctls to seed defaults for feature negotiation
    102 */
    103extern unsigned long sysctl_dccp_sequence_window;
    104extern int	     sysctl_dccp_rx_ccid;
    105extern int	     sysctl_dccp_tx_ccid;
    106
    107int dccp_feat_init(struct sock *sk);
    108void dccp_feat_initialise_sysctls(void);
    109int dccp_feat_register_sp(struct sock *sk, u8 feat, u8 is_local,
    110			  u8 const *list, u8 len);
    111int dccp_feat_parse_options(struct sock *, struct dccp_request_sock *,
    112			    u8 mand, u8 opt, u8 feat, u8 *val, u8 len);
    113int dccp_feat_clone_list(struct list_head const *, struct list_head *);
    114
    115/*
    116 * Encoding variable-length options and their maximum length.
    117 *
    118 * This affects NN options (SP options are all u8) and other variable-length
    119 * options (see table 3 in RFC 4340). The limit is currently given the Sequence
    120 * Window NN value (sec. 7.5.2) and the NDP count (sec. 7.7) option, all other
    121 * options consume less than 6 bytes (timestamps are 4 bytes).
    122 * When updating this constant (e.g. due to new internet drafts / RFCs), make
    123 * sure that you also update all code which refers to it.
    124 */
    125#define DCCP_OPTVAL_MAXLEN	6
    126
    127void dccp_encode_value_var(const u64 value, u8 *to, const u8 len);
    128u64 dccp_decode_value_var(const u8 *bf, const u8 len);
    129u64 dccp_feat_nn_get(struct sock *sk, u8 feat);
    130
    131int dccp_insert_option_mandatory(struct sk_buff *skb);
    132int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat, u8 *val, u8 len,
    133		       bool repeat_first);
    134#endif /* _DCCP_FEAT_H */