linux/net/dccp/options.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  net/dccp/options.c
 *
 *  An implementation of the DCCP protocol
 *  Copyright (c) 2005 Aristeu Sergio Rozanski Filho <[email protected]>
 *  Copyright (c) 2005 Arnaldo Carvalho de Melo <[email protected]>
 *  Copyright (c) 2005 Ian McDonald <[email protected]>
 */
#include <linux/dccp.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/unaligned.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>

#include "ackvec.h"
#include "ccid.h"
#include "dccp.h"
#include "feat.h"

u64 dccp_decode_value_var(const u8 *bf, const u8 len)
{ … }

/**
 * dccp_parse_options  -  Parse DCCP options present in @skb
 * @sk: client|server|listening dccp socket (when @dreq != NULL)
 * @dreq: request socket to use during connection setup, or NULL
 * @skb: frame to parse
 */
int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
		       struct sk_buff *skb)
{ … }

EXPORT_SYMBOL_GPL(…);

void dccp_encode_value_var(const u64 value, u8 *to, const u8 len)
{ … }

static inline u8 dccp_ndp_len(const u64 ndp)
{ … }

int dccp_insert_option(struct sk_buff *skb, const unsigned char option,
		       const void *value, const unsigned char len)
{ … }

EXPORT_SYMBOL_GPL(…);

static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb)
{ … }

static inline int dccp_elapsed_time_len(const u32 elapsed_time)
{ … }

static int dccp_insert_option_timestamp(struct sk_buff *skb)
{ … }

static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp,
					     struct dccp_request_sock *dreq,
					     struct sk_buff *skb)
{ … }

static int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb)
{ … }

/**
 * dccp_insert_option_mandatory  -  Mandatory option (5.8.2)
 * @skb: frame into which to insert option
 *
 * Note that since we are using skb_push, this function needs to be called
 * _after_ inserting the option it is supposed to influence (stack order).
 */
int dccp_insert_option_mandatory(struct sk_buff *skb)
{ … }

/**
 * dccp_insert_fn_opt  -  Insert single Feature-Negotiation option into @skb
 * @skb: frame to insert feature negotiation option into
 * @type: %DCCPO_CHANGE_L, %DCCPO_CHANGE_R, %DCCPO_CONFIRM_L, %DCCPO_CONFIRM_R
 * @feat: one out of %dccp_feature_numbers
 * @val: NN value or SP array (preferred element first) to copy
 * @len: true length of @val in bytes (excluding first element repetition)
 * @repeat_first: whether to copy the first element of @val twice
 *
 * The last argument is used to construct Confirm options, where the preferred
 * value and the preference list appear separately (RFC 4340, 6.3.1). Preference
 * lists are kept such that the preferred entry is always first, so we only need
 * to copy twice, and avoid the overhead of cloning into a bigger array.
 */
int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat,
		       u8 *val, u8 len, bool repeat_first)
{ … }

/* The length of all options needs to be a multiple of 4 (5.8) */
static void dccp_insert_option_padding(struct sk_buff *skb)
{ … }

int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
{ … }

int dccp_insert_options_rsk(struct dccp_request_sock *dreq, struct sk_buff *skb)
{ … }