[net-next-2.6.git] / net / dccp / options.c

/*
 *  net/dccp/options.c
 *
 *  An implementation of the DCCP protocol
 *  Copyright (c) 2005 Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
 *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
 *  Copyright (c) 2005 Ian McDonald <ian.mcdonald@jandi.co.nz>
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */
#include <linux/dccp.h>
#include <linux/module.h>
#include <linux/types.h>
#include <asm/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)
{
	u64 value = 0;

	if (len >= DCCP_OPTVAL_MAXLEN)
		value += ((u64)*bf++) << 40;
	if (len > 4)
		value += ((u64)*bf++) << 32;
	if (len > 3)
		value += ((u64)*bf++) << 24;
	if (len > 2)
		value += ((u64)*bf++) << 16;
	if (len > 1)
		value += ((u64)*bf++) << 8;
	if (len > 0)
		value += *bf;

	return value;
}

/**
 * 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
 */
int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
		       struct sk_buff *skb)
{
	struct dccp_sock *dp = dccp_sk(sk);
	const struct dccp_hdr *dh = dccp_hdr(skb);
	const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type;
	unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb);
	unsigned char *opt_ptr = options;
	const unsigned char *opt_end = (unsigned char *)dh +
					(dh->dccph_doff * 4);
	struct dccp_options_received *opt_recv = &dp->dccps_options_received;
	unsigned char opt, len;
	unsigned char *uninitialized_var(value);
	u32 elapsed_time;
	__be32 opt_val;
	int rc;
	int mandatory = 0;

	memset(opt_recv, 0, sizeof(*opt_recv));

	opt = len = 0;
	while (opt_ptr != opt_end) {
		opt   = *opt_ptr++;
		len   = 0;
		value = NULL;

		/* Check if this isn't a single byte option */
		if (opt > DCCPO_MAX_RESERVED) {
			if (opt_ptr == opt_end)
				goto out_nonsensical_length;

			len = *opt_ptr++;
			if (len < 2)
				goto out_nonsensical_length;
			/*
			 * Remove the type and len fields, leaving
			 * just the value size
			 */
			len	-= 2;
			value	= opt_ptr;
			opt_ptr += len;

			if (opt_ptr > opt_end)
				goto out_nonsensical_length;
		}

		/*
		 * CCID-specific options are ignored during connection setup, as
		 * negotiation may still be in progress (see RFC 4340, 10.3).
		 * The same applies to Ack Vectors, as these depend on the CCID.
		 */
		if (dreq != NULL && (opt >= DCCPO_MIN_RX_CCID_SPECIFIC ||
		    opt == DCCPO_ACK_VECTOR_0 || opt == DCCPO_ACK_VECTOR_1))
			goto ignore_option;

		switch (opt) {
		case DCCPO_PADDING:
			break;
		case DCCPO_MANDATORY:
			if (mandatory)
				goto out_invalid_option;
			if (pkt_type != DCCP_PKT_DATA)
				mandatory = 1;
			break;
		case DCCPO_NDP_COUNT:
			if (len > 6)
				goto out_invalid_option;

			opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
			dccp_pr_debug("%s opt: NDP count=%llu\n", dccp_role(sk),
				      (unsigned long long)opt_recv->dccpor_ndp);
			break;
		case DCCPO_CHANGE_L ... DCCPO_CONFIRM_R:
			if (pkt_type == DCCP_PKT_DATA)      /* RFC 4340, 6 */
				break;
			rc = dccp_feat_parse_options(sk, dreq, mandatory, opt,
						    *value, value + 1, len - 1);
			if (rc)
				goto out_featneg_failed;
			break;
		case DCCPO_ACK_VECTOR_0:
		case DCCPO_ACK_VECTOR_1:
			if (dccp_packet_without_ack(skb))   /* RFC 4340, 11.4 */
				break;
			dccp_pr_debug("%s Ack Vector (len=%u)\n", dccp_role(sk),
				      len);
			break;
		case DCCPO_TIMESTAMP:
			if (len != 4)
				goto out_invalid_option;
			/*
			 * RFC 4340 13.1: "The precise time corresponding to
			 * Timestamp Value zero is not specified". We use
			 * zero to indicate absence of a meaningful timestamp.
			 */
			opt_val = get_unaligned((__be32 *)value);
			if (unlikely(opt_val == 0)) {
				DCCP_WARN("Timestamp with zero value\n");
				break;
			}

			if (dreq != NULL) {
				dreq->dreq_timestamp_echo = ntohl(opt_val);
				dreq->dreq_timestamp_time = dccp_timestamp();
			} else {
				opt_recv->dccpor_timestamp =
					dp->dccps_timestamp_echo = ntohl(opt_val);
				dp->dccps_timestamp_time = dccp_timestamp();
			}
			dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n",
				      dccp_role(sk), ntohl(opt_val),
				      (unsigned long long)
				      DCCP_SKB_CB(skb)->dccpd_ack_seq);
			/* schedule an Ack in case this sender is quiescent */
			inet_csk_schedule_ack(sk);
			break;
		case DCCPO_TIMESTAMP_ECHO:
			if (len != 4 && len != 6 && len != 8)
				goto out_invalid_option;

			opt_val = get_unaligned((__be32 *)value);
			opt_recv->dccpor_timestamp_echo = ntohl(opt_val);

			dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, "
				      "ackno=%llu", dccp_role(sk),
				      opt_recv->dccpor_timestamp_echo,
				      len + 2,
				      (unsigned long long)
				      DCCP_SKB_CB(skb)->dccpd_ack_seq);

			value += 4;

			if (len == 4) {		/* no elapsed time included */
				dccp_pr_debug_cat("\n");
				break;
			}

			if (len == 6) {		/* 2-byte elapsed time */
				__be16 opt_val2 = get_unaligned((__be16 *)value);
				elapsed_time = ntohs(opt_val2);
			} else {		/* 4-byte elapsed time */
				opt_val = get_unaligned((__be32 *)value);
				elapsed_time = ntohl(opt_val);
			}

			dccp_pr_debug_cat(", ELAPSED_TIME=%u\n", elapsed_time);

			/* Give precedence to the biggest ELAPSED_TIME */
			if (elapsed_time > opt_recv->dccpor_elapsed_time)
				opt_recv->dccpor_elapsed_time = elapsed_time;
			break;
		case DCCPO_ELAPSED_TIME:
			if (dccp_packet_without_ack(skb))   /* RFC 4340, 13.2 */
				break;

			if (len == 2) {
				__be16 opt_val2 = get_unaligned((__be16 *)value);
				elapsed_time = ntohs(opt_val2);
			} else if (len == 4) {
				opt_val = get_unaligned((__be32 *)value);
				elapsed_time = ntohl(opt_val);
			} else {
				goto out_invalid_option;
			}

			if (elapsed_time > opt_recv->dccpor_elapsed_time)
				opt_recv->dccpor_elapsed_time = elapsed_time;

			dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n",
				      dccp_role(sk), elapsed_time);
			break;
		case DCCPO_MIN_RX_CCID_SPECIFIC ... DCCPO_MAX_RX_CCID_SPECIFIC:
			if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
						     pkt_type, opt, value, len))
				goto out_invalid_option;
			break;
		case DCCPO_MIN_TX_CCID_SPECIFIC ... DCCPO_MAX_TX_CCID_SPECIFIC:
			if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
						     pkt_type, opt, value, len))
				goto out_invalid_option;
			break;
		default:
			DCCP_CRIT("DCCP(%p): option %d(len=%d) not "
				  "implemented, ignoring", sk, opt, len);
			break;
		}
ignore_option:
		if (opt != DCCPO_MANDATORY)
			mandatory = 0;
	}

	/* mandatory was the last byte in option list -> reset connection */
	if (mandatory)
		goto out_invalid_option;

out_nonsensical_length:
	/* RFC 4340, 5.8: ignore option and all remaining option space */
	return 0;

out_invalid_option:
	DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
	rc = DCCP_RESET_CODE_OPTION_ERROR;
out_featneg_failed:
	DCCP_WARN("DCCP(%p): Option %d (len=%d) error=%u\n", sk, opt, len, rc);
	DCCP_SKB_CB(skb)->dccpd_reset_code = rc;
	DCCP_SKB_CB(skb)->dccpd_reset_data[0] = opt;
	DCCP_SKB_CB(skb)->dccpd_reset_data[1] = len > 0 ? value[0] : 0;
	DCCP_SKB_CB(skb)->dccpd_reset_data[2] = len > 1 ? value[1] : 0;
	return -1;
}

EXPORT_SYMBOL_GPL(dccp_parse_options);

void dccp_encode_value_var(const u64 value, u8 *to, const u8 len)
{
	if (len >= DCCP_OPTVAL_MAXLEN)
		*to++ = (value & 0xFF0000000000ull) >> 40;
	if (len > 4)
		*to++ = (value & 0xFF00000000ull) >> 32;
	if (len > 3)
		*to++ = (value & 0xFF000000) >> 24;
	if (len > 2)
		*to++ = (value & 0xFF0000) >> 16;
	if (len > 1)
		*to++ = (value & 0xFF00) >> 8;
	if (len > 0)
		*to++ = (value & 0xFF);
}

static inline u8 dccp_ndp_len(const u64 ndp)
{
	if (likely(ndp <= 0xFF))
		return 1;
	return likely(ndp <= USHRT_MAX) ? 2 : (ndp <= UINT_MAX ? 4 : 6);
}

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

	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN)
		return -1;

	DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;

	to    = skb_push(skb, len + 2);
	*to++ = option;
	*to++ = len + 2;

	memcpy(to, value, len);
	return 0;
}

EXPORT_SYMBOL_GPL(dccp_insert_option);

static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb)
{
	struct dccp_sock *dp = dccp_sk(sk);
	u64 ndp = dp->dccps_ndp_count;

	if (dccp_non_data_packet(skb))
		++dp->dccps_ndp_count;
	else
		dp->dccps_ndp_count = 0;

	if (ndp > 0) {
		unsigned char *ptr;
		const int ndp_len = dccp_ndp_len(ndp);
		const int len = ndp_len + 2;

		if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
			return -1;

		DCCP_SKB_CB(skb)->dccpd_opt_len += len;

		ptr = skb_push(skb, len);
		*ptr++ = DCCPO_NDP_COUNT;
		*ptr++ = len;
		dccp_encode_value_var(ndp, ptr, ndp_len);
	}

	return 0;
}

static inline int dccp_elapsed_time_len(const u32 elapsed_time)
{
	return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
}

/* FIXME: This function is currently not used anywhere */
int dccp_insert_option_elapsed_time(struct sk_buff *skb, u32 elapsed_time)
{
	const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
	const int len = 2 + elapsed_time_len;
	unsigned char *to;

	if (elapsed_time_len == 0)
		return 0;

	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
		return -1;

	DCCP_SKB_CB(skb)->dccpd_opt_len += len;

	to    = skb_push(skb, len);
	*to++ = DCCPO_ELAPSED_TIME;
	*to++ = len;

	if (elapsed_time_len == 2) {
		const __be16 var16 = htons((u16)elapsed_time);
		memcpy(to, &var16, 2);
	} else {
		const __be32 var32 = htonl(elapsed_time);
		memcpy(to, &var32, 4);
	}

	return 0;
}

EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);

static int dccp_insert_option_timestamp(struct sk_buff *skb)
{
	__be32 now = htonl(dccp_timestamp());
	/* yes this will overflow but that is the point as we want a
	 * 10 usec 32 bit timer which mean it wraps every 11.9 hours */

	return dccp_insert_option(skb, DCCPO_TIMESTAMP, &now, sizeof(now));
}

static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp,
					     struct dccp_request_sock *dreq,
					     struct sk_buff *skb)
{
	__be32 tstamp_echo;
	unsigned char *to;
	u32 elapsed_time, elapsed_time_len, len;

	if (dreq != NULL) {
		elapsed_time = dccp_timestamp() - dreq->dreq_timestamp_time;
		tstamp_echo  = htonl(dreq->dreq_timestamp_echo);
		dreq->dreq_timestamp_echo = 0;
	} else {
		elapsed_time = dccp_timestamp() - dp->dccps_timestamp_time;
		tstamp_echo  = htonl(dp->dccps_timestamp_echo);
		dp->dccps_timestamp_echo = 0;
	}

	elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
	len = 6 + elapsed_time_len;

	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
		return -1;

	DCCP_SKB_CB(skb)->dccpd_opt_len += len;

	to    = skb_push(skb, len);
	*to++ = DCCPO_TIMESTAMP_ECHO;
	*to++ = len;

	memcpy(to, &tstamp_echo, 4);
	to += 4;

	if (elapsed_time_len == 2) {
		const __be16 var16 = htons((u16)elapsed_time);
		memcpy(to, &var16, 2);
	} else if (elapsed_time_len == 4) {
		const __be32 var32 = htonl(elapsed_time);
		memcpy(to, &var32, 4);
	}

	return 0;
}

static int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb)
{
	struct dccp_sock *dp = dccp_sk(sk);
	struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec;
	const u16 buflen = dccp_ackvec_buflen(av);
	/* Figure out how many options do we need to represent the ackvec */
	const u8 nr_opts = DIV_ROUND_UP(buflen, DCCP_SINGLE_OPT_MAXLEN);
	u16 len = buflen + 2 * nr_opts;
	u8 i, nonce = 0;
	const unsigned char *tail, *from;
	unsigned char *to;

	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
		return -1;

	DCCP_SKB_CB(skb)->dccpd_opt_len += len;

	to   = skb_push(skb, len);
	len  = buflen;
	from = av->av_buf + av->av_buf_head;
	tail = av->av_buf + DCCPAV_MAX_ACKVEC_LEN;

	for (i = 0; i < nr_opts; ++i) {
		int copylen = len;

		if (len > DCCP_SINGLE_OPT_MAXLEN)
			copylen = DCCP_SINGLE_OPT_MAXLEN;

		/*
		 * RFC 4340, 12.2: Encode the Nonce Echo for this Ack Vector via
		 * its type; ack_nonce is the sum of all individual buf_nonce's.
		 */
		nonce ^= av->av_buf_nonce[i];

		*to++ = DCCPO_ACK_VECTOR_0 + av->av_buf_nonce[i];
		*to++ = copylen + 2;

		/* Check if buf_head wraps */
		if (from + copylen > tail) {
			const u16 tailsize = tail - from;

			memcpy(to, from, tailsize);
			to	+= tailsize;
			len	-= tailsize;
			copylen	-= tailsize;
			from	= av->av_buf;
		}

		memcpy(to, from, copylen);
		from += copylen;
		to   += copylen;
		len  -= copylen;
	}
	/*
	 * Each sent Ack Vector is recorded in the list, as per A.2 of RFC 4340.
	 */
	if (dccp_ackvec_update_records(av, DCCP_SKB_CB(skb)->dccpd_seq, nonce))
		return -ENOBUFS;
	return 0;
}

/**
 * dccp_insert_option_mandatory  -  Mandatory option (5.8.2)
 * 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)
{
	if (DCCP_SKB_CB(skb)->dccpd_opt_len >= DCCP_MAX_OPT_LEN)
		return -1;

	DCCP_SKB_CB(skb)->dccpd_opt_len++;
	*skb_push(skb, 1) = DCCPO_MANDATORY;
	return 0;
}

/**
 * dccp_insert_fn_opt  -  Insert single Feature-Negotiation option into @skb
 * @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)
{
	u8 tot_len, *to;

	/* take the `Feature' field and possible repetition into account */
	if (len > (DCCP_SINGLE_OPT_MAXLEN - 2)) {
		DCCP_WARN("length %u for feature %u too large\n", len, feat);
		return -1;
	}

	if (unlikely(val == NULL || len == 0))
		len = repeat_first = 0;
	tot_len = 3 + repeat_first + len;

	if (DCCP_SKB_CB(skb)->dccpd_opt_len + tot_len > DCCP_MAX_OPT_LEN) {
		DCCP_WARN("packet too small for feature %d option!\n", feat);
		return -1;
	}
	DCCP_SKB_CB(skb)->dccpd_opt_len += tot_len;

	to    = skb_push(skb, tot_len);
	*to++ = type;
	*to++ = tot_len;
	*to++ = feat;

	if (repeat_first)
		*to++ = *val;
	if (len)
		memcpy(to, val, len);
	return 0;
}

/* 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 padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4;

	if (padding != 0) {
		padding = 4 - padding;
		memset(skb_push(skb, padding), 0, padding);
		DCCP_SKB_CB(skb)->dccpd_opt_len += padding;
	}
}

int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
{
	struct dccp_sock *dp = dccp_sk(sk);

	DCCP_SKB_CB(skb)->dccpd_opt_len = 0;

	if (dp->dccps_send_ndp_count && dccp_insert_option_ndp(sk, skb))
		return -1;

	if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA) {

		/* Feature Negotiation */
		if (dccp_feat_insert_opts(dp, NULL, skb))
			return -1;

		if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST) {
			/*
			 * Obtain RTT sample from Request/Response exchange.
			 * This is currently used for TFRC initialisation.
			 */
			if (dccp_insert_option_timestamp(skb))
				return -1;

		} else if (dccp_ackvec_pending(sk) &&
			   dccp_insert_option_ackvec(sk, skb)) {
				return -1;
		}
	}

	if (dp->dccps_hc_rx_insert_options) {
		if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb))
			return -1;
		dp->dccps_hc_rx_insert_options = 0;
	}

	if (dp->dccps_timestamp_echo != 0 &&
	    dccp_insert_option_timestamp_echo(dp, NULL, skb))
		return -1;

	dccp_insert_option_padding(skb);
	return 0;
}

int dccp_insert_options_rsk(struct dccp_request_sock *dreq, struct sk_buff *skb)
{
	DCCP_SKB_CB(skb)->dccpd_opt_len = 0;

	if (dccp_feat_insert_opts(NULL, dreq, skb))
		return -1;

	/* Obtain RTT sample from Response/Ack exchange (used by TFRC). */
	if (dccp_insert_option_timestamp(skb))
		return -1;

	if (dreq->dreq_timestamp_echo != 0 &&
	    dccp_insert_option_timestamp_echo(NULL, dreq, skb))
		return -1;

	dccp_insert_option_padding(skb);
	return 0;
}
Commit	Line	Data
7c657876 ACM	1	/*
	2	* net/dccp/options.c
	3	*
	4	* An implementation of the DCCP protocol
1bc09869 IM	5	* Copyright (c) 2005 Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
1bc09869 IM	6	* Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
e6bccd35	7	* Copyright (c) 2005 Ian McDonald <ian.mcdonald@jandi.co.nz>
7c657876 ACM	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License
	11	* as published by the Free Software Foundation; either version
	12	* 2 of the License, or (at your option) any later version.
	13	*/
7c657876 ACM	14	#include <linux/dccp.h>
	15	#include <linux/module.h>
	16	#include <linux/types.h>
76fd1e87	17	#include <asm/unaligned.h>
7c657876 ACM	18	#include <linux/kernel.h>
	19	#include <linux/skbuff.h>
	20
ae31c339	21	#include "ackvec.h"
7c657876 ACM	22	#include "ccid.h"
7c657876 ACM	23	#include "dccp.h"
afe00251	24	#include "feat.h"
7c657876	25
02fa460e	26	u64 dccp_decode_value_var(const u8 *bf, const u8 len)
7c657876	27	{
02fa460e	28	u64 value = 0;
7c657876	29
02fa460e GR	30	if (len >= DCCP_OPTVAL_MAXLEN)
	31	value += ((u64)*bf++) << 40;
	32	if (len > 4)
	33	value += ((u64)*bf++) << 32;
7c657876	34	if (len > 3)
02fa460e	35	value += ((u64)*bf++) << 24;
7c657876	36	if (len > 2)
02fa460e	37	value += ((u64)*bf++) << 16;
7c657876	38	if (len > 1)
02fa460e	39	value += ((u64)*bf++) << 8;
7c657876 ACM	40	if (len > 0)
	41	value += *bf;
	42
	43	return value;
	44	}
	45
8b819412 GR	46	/**
	47	* dccp_parse_options - Parse DCCP options present in @skb
	48	* @sk: client\|server\|listening dccp socket (when @dreq != NULL)
	49	* @dreq: request socket to use during connection setup, or NULL
	50	*/
	51	int dccp_parse_options(struct sock sk, struct dccp_request_sock dreq,
	52	struct sk_buff *skb)
7c657876 ACM	53	{
7c657876 ACM	54	struct dccp_sock *dp = dccp_sk(sk);
7c657876 ACM	55	const struct dccp_hdr *dh = dccp_hdr(skb);
	56	const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type;
	57	unsigned char options = (unsigned char )dh + dccp_hdr_len(skb);
	58	unsigned char *opt_ptr = options;
7690af3f ACM	59	const unsigned char opt_end = (unsigned char )dh +
7690af3f ACM	60	(dh->dccph_doff * 4);
7c657876 ACM	61	struct dccp_options_received *opt_recv = &dp->dccps_options_received;
7c657876 ACM	62	unsigned char opt, len;
3ed7cc0f	63	unsigned char *uninitialized_var(value);
1c14ac0a	64	u32 elapsed_time;
76fd1e87	65	__be32 opt_val;
afe00251 AB	66	int rc;
afe00251 AB	67	int mandatory = 0;
7c657876 ACM	68
	69	memset(opt_recv, 0, sizeof(*opt_recv));
	70
fb950496	71	opt = len = 0;
7c657876 ACM	72	while (opt_ptr != opt_end) {
	73	opt = *opt_ptr++;
	74	len = 0;
	75	value = NULL;
	76
	77	/* Check if this isn't a single byte option */
	78	if (opt > DCCPO_MAX_RESERVED) {
	79	if (opt_ptr == opt_end)
faf61c33	80	goto out_nonsensical_length;
7c657876 ACM	81
7c657876 ACM	82	len = *opt_ptr++;
faf61c33 GR	83	if (len < 2)
faf61c33 GR	84	goto out_nonsensical_length;
7c657876 ACM	85	/*
	86	* Remove the type and len fields, leaving
	87	* just the value size
	88	*/
	89	len -= 2;
	90	value = opt_ptr;
	91	opt_ptr += len;
	92
	93	if (opt_ptr > opt_end)
faf61c33	94	goto out_nonsensical_length;
7c657876 ACM	95	}
7c657876 ACM	96
8b819412	97	/*
8b819412 GR	98	* CCID-specific options are ignored during connection setup, as
8b819412 GR	99	* negotiation may still be in progress (see RFC 4340, 10.3).
65907a43	100	* The same applies to Ack Vectors, as these depend on the CCID.
8b819412	101	*/
a18213d1	102	if (dreq != NULL && (opt >= DCCPO_MIN_RX_CCID_SPECIFIC \|\|
65907a43	103	opt == DCCPO_ACK_VECTOR_0 \|\| opt == DCCPO_ACK_VECTOR_1))
8b819412 GR	104	goto ignore_option;
8b819412 GR	105
7c657876 ACM	106	switch (opt) {
	107	case DCCPO_PADDING:
	108	break;
afe00251 AB	109	case DCCPO_MANDATORY:
	110	if (mandatory)
	111	goto out_invalid_option;
6df9424a ACM	112	if (pkt_type != DCCP_PKT_DATA)
6df9424a ACM	113	mandatory = 1;
afe00251	114	break;
7c657876	115	case DCCPO_NDP_COUNT:
5b5d0e70	116	if (len > 6)
7c657876 ACM	117	goto out_invalid_option;
	118
	119	opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
5b5d0e70 GR	120	dccp_pr_debug("%s opt: NDP count=%llu\n", dccp_role(sk),
5b5d0e70 GR	121	(unsigned long long)opt_recv->dccpor_ndp);
7c657876	122	break;
b1ad0042 GR	123	case DCCPO_CHANGE_L ... DCCPO_CONFIRM_R:
b1ad0042 GR	124	if (pkt_type == DCCP_PKT_DATA) /* RFC 4340, 6 */
cf86314c	125	break;
e77b8363 GR	126	rc = dccp_feat_parse_options(sk, dreq, mandatory, opt,
	127	*value, value + 1, len - 1);
	128	if (rc)
	129	goto out_featneg_failed;
410e27a4	130	break;
410e27a4 GR	131	case DCCPO_ACK_VECTOR_0:
	132	case DCCPO_ACK_VECTOR_1:
	133	if (dccp_packet_without_ack(skb)) /* RFC 4340, 11.4 */
	134	break;
5753fdfe GR	135	dccp_pr_debug("%s Ack Vector (len=%u)\n", dccp_role(sk),
5753fdfe GR	136	len);
afe00251	137	break;
7c657876 ACM	138	case DCCPO_TIMESTAMP:
	139	if (len != 4)
	140	goto out_invalid_option;
b4d4f7c7 GR	141	/*
	142	* RFC 4340 13.1: "The precise time corresponding to
	143	* Timestamp Value zero is not specified". We use
	144	* zero to indicate absence of a meaningful timestamp.
	145	*/
76fd1e87	146	opt_val = get_unaligned((__be32 *)value);
b4d4f7c7 GR	147	if (unlikely(opt_val == 0)) {
	148	DCCP_WARN("Timestamp with zero value\n");
	149	break;
	150	}
7c657876	151
b4d4f7c7 GR	152	if (dreq != NULL) {
	153	dreq->dreq_timestamp_echo = ntohl(opt_val);
	154	dreq->dreq_timestamp_time = dccp_timestamp();
	155	} else {
	156	opt_recv->dccpor_timestamp =
	157	dp->dccps_timestamp_echo = ntohl(opt_val);
	158	dp->dccps_timestamp_time = dccp_timestamp();
	159	}
09dbc389	160	dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n",
b4d4f7c7	161	dccp_role(sk), ntohl(opt_val),
f6ccf554	162	(unsigned long long)
7c657876	163	DCCP_SKB_CB(skb)->dccpd_ack_seq);
ecdfbdab GR	164	/* schedule an Ack in case this sender is quiescent */
ecdfbdab GR	165	inet_csk_schedule_ack(sk);
7c657876 ACM	166	break;
7c657876 ACM	167	case DCCPO_TIMESTAMP_ECHO:
1bc09869	168	if (len != 4 && len != 6 && len != 8)
7c657876 ACM	169	goto out_invalid_option;
7c657876 ACM	170
76fd1e87 GR	171	opt_val = get_unaligned((__be32 *)value);
76fd1e87 GR	172	opt_recv->dccpor_timestamp_echo = ntohl(opt_val);
7c657876	173
09dbc389	174	dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, "
f73f7097	175	"ackno=%llu", dccp_role(sk),
7690af3f	176	opt_recv->dccpor_timestamp_echo,
f6ccf554 DM	177	len + 2,
f6ccf554 DM	178	(unsigned long long)
1bc09869 IM	179	DCCP_SKB_CB(skb)->dccpd_ack_seq);
1bc09869 IM	180
76fd1e87	181	value += 4;
1bc09869	182
76fd1e87	183	if (len == 4) { /* no elapsed time included */
f73f7097	184	dccp_pr_debug_cat("\n");
1c14ac0a	185	break;
f73f7097	186	}
1c14ac0a	187
76fd1e87 GR	188	if (len == 6) { /* 2-byte elapsed time */
	189	__be16 opt_val2 = get_unaligned((__be16 *)value);
	190	elapsed_time = ntohs(opt_val2);
	191	} else { /* 4-byte elapsed time */
	192	opt_val = get_unaligned((__be32 *)value);
	193	elapsed_time = ntohl(opt_val);
	194	}
1c14ac0a	195
dcad856f	196	dccp_pr_debug_cat(", ELAPSED_TIME=%u\n", elapsed_time);
f73f7097	197
1c14ac0a ACM	198	/* Give precedence to the biggest ELAPSED_TIME */
	199	if (elapsed_time > opt_recv->dccpor_elapsed_time)
	200	opt_recv->dccpor_elapsed_time = elapsed_time;
7c657876 ACM	201	break;
7c657876 ACM	202	case DCCPO_ELAPSED_TIME:
c86ab2b6 GR	203	if (dccp_packet_without_ack(skb)) /* RFC 4340, 13.2 */
c86ab2b6 GR	204	break;
1bc09869	205
76fd1e87 GR	206	if (len == 2) {
	207	__be16 opt_val2 = get_unaligned((__be16 *)value);
	208	elapsed_time = ntohs(opt_val2);
c86ab2b6	209	} else if (len == 4) {
76fd1e87 GR	210	opt_val = get_unaligned((__be32 *)value);
76fd1e87 GR	211	elapsed_time = ntohl(opt_val);
c86ab2b6 GR	212	} else {
c86ab2b6 GR	213	goto out_invalid_option;
76fd1e87	214	}
1c14ac0a ACM	215
	216	if (elapsed_time > opt_recv->dccpor_elapsed_time)
	217	opt_recv->dccpor_elapsed_time = elapsed_time;
1bc09869	218
09dbc389 GR	219	dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n",
09dbc389 GR	220	dccp_role(sk), elapsed_time);
7c657876	221	break;
a18213d1	222	case DCCPO_MIN_RX_CCID_SPECIFIC ... DCCPO_MAX_RX_CCID_SPECIFIC:
7690af3f	223	if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
4874c131	224	pkt_type, opt, value, len))
7c657876	225	goto out_invalid_option;
7c657876	226	break;
a18213d1	227	case DCCPO_MIN_TX_CCID_SPECIFIC ... DCCPO_MAX_TX_CCID_SPECIFIC:
7690af3f	228	if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
4874c131	229	pkt_type, opt, value, len))
7c657876	230	goto out_invalid_option;
7c657876 ACM	231	break;
7c657876 ACM	232	default:
59348b19 GR	233	DCCP_CRIT("DCCP(%p): option %d(len=%d) not "
59348b19 GR	234	"implemented, ignoring", sk, opt, len);
7c657876	235	break;
c9eaf173	236	}
8b819412	237	ignore_option:
afe00251 AB	238	if (opt != DCCPO_MANDATORY)
afe00251 AB	239	mandatory = 0;
7c657876 ACM	240	}
7c657876 ACM	241
6df9424a ACM	242	/* mandatory was the last byte in option list -> reset connection */
	243	if (mandatory)
	244	goto out_invalid_option;
	245
faf61c33 GR	246	out_nonsensical_length:
faf61c33 GR	247	/* RFC 4340, 5.8: ignore option and all remaining option space */
7c657876 ACM	248	return 0;
	249
	250	out_invalid_option:
	251	DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
e77b8363 GR	252	rc = DCCP_RESET_CODE_OPTION_ERROR;
	253	out_featneg_failed:
	254	DCCP_WARN("DCCP(%p): Option %d (len=%d) error=%u\n", sk, opt, len, rc);
	255	DCCP_SKB_CB(skb)->dccpd_reset_code = rc;
eac7726b GR	256	DCCP_SKB_CB(skb)->dccpd_reset_data[0] = opt;
	257	DCCP_SKB_CB(skb)->dccpd_reset_data[1] = len > 0 ? value[0] : 0;
	258	DCCP_SKB_CB(skb)->dccpd_reset_data[2] = len > 1 ? value[1] : 0;
7c657876 ACM	259	return -1;
	260	}
	261
b61fafc4 ACM	262	EXPORT_SYMBOL_GPL(dccp_parse_options);
b61fafc4 ACM	263
02fa460e	264	void dccp_encode_value_var(const u64 value, u8 *to, const u8 len)
7c657876	265	{
02fa460e GR	266	if (len >= DCCP_OPTVAL_MAXLEN)
	267	*to++ = (value & 0xFF0000000000ull) >> 40;
	268	if (len > 4)
	269	*to++ = (value & 0xFF00000000ull) >> 32;
7c657876 ACM	270	if (len > 3)
	271	*to++ = (value & 0xFF000000) >> 24;
	272	if (len > 2)
	273	*to++ = (value & 0xFF0000) >> 16;
	274	if (len > 1)
	275	*to++ = (value & 0xFF00) >> 8;
	276	if (len > 0)
	277	*to++ = (value & 0xFF);
	278	}
	279
5b5d0e70	280	static inline u8 dccp_ndp_len(const u64 ndp)
7c657876	281	{
5b5d0e70 GR	282	if (likely(ndp <= 0xFF))
5b5d0e70 GR	283	return 1;
4be929be	284	return likely(ndp <= USHRT_MAX) ? 2 : (ndp <= UINT_MAX ? 4 : 6);
7c657876 ACM	285	}
7c657876 ACM	286
a7d13fbf GR	287	int dccp_insert_option(struct sk_buff *skb, const unsigned char option,
a7d13fbf GR	288	const void *value, const unsigned char len)
7c657876 ACM	289	{
	290	unsigned char *to;
	291
2d0817d1 ACM	292	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN)
2d0817d1 ACM	293	return -1;
7c657876 ACM	294
	295	DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
	296
	297	to = skb_push(skb, len + 2);
	298	*to++ = option;
	299	*to++ = len + 2;
	300
	301	memcpy(to, value, len);
2d0817d1	302	return 0;
7c657876 ACM	303	}
	304
	305	EXPORT_SYMBOL_GPL(dccp_insert_option);
	306
2d0817d1	307	static int dccp_insert_option_ndp(struct sock sk, struct sk_buff skb)
7c657876 ACM	308	{
7c657876 ACM	309	struct dccp_sock *dp = dccp_sk(sk);
5b5d0e70	310	u64 ndp = dp->dccps_ndp_count;
7c657876 ACM	311
	312	if (dccp_non_data_packet(skb))
	313	++dp->dccps_ndp_count;
	314	else
	315	dp->dccps_ndp_count = 0;
	316
	317	if (ndp > 0) {
	318	unsigned char *ptr;
	319	const int ndp_len = dccp_ndp_len(ndp);
	320	const int len = ndp_len + 2;
	321
	322	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
2d0817d1	323	return -1;
7c657876 ACM	324
	325	DCCP_SKB_CB(skb)->dccpd_opt_len += len;
	326
	327	ptr = skb_push(skb, len);
	328	*ptr++ = DCCPO_NDP_COUNT;
	329	*ptr++ = len;
	330	dccp_encode_value_var(ndp, ptr, ndp_len);
	331	}
2d0817d1 ACM	332
2d0817d1 ACM	333	return 0;
7c657876 ACM	334	}
	335
	336	static inline int dccp_elapsed_time_len(const u32 elapsed_time)
	337	{
b1c9fe7b	338	return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
7c657876 ACM	339	}
7c657876 ACM	340
f17a37c9	341	/* FIXME: This function is currently not used anywhere */
a7d13fbf	342	int dccp_insert_option_elapsed_time(struct sk_buff *skb, u32 elapsed_time)
7c657876	343	{
7c657876 ACM	344	const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
	345	const int len = 2 + elapsed_time_len;
	346	unsigned char *to;
	347
1bc09869	348	if (elapsed_time_len == 0)
2d0817d1	349	return 0;
7c657876	350
2d0817d1 ACM	351	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
2d0817d1 ACM	352	return -1;
7c657876 ACM	353
	354	DCCP_SKB_CB(skb)->dccpd_opt_len += len;
	355
	356	to = skb_push(skb, len);
	357	*to++ = DCCPO_ELAPSED_TIME;
	358	*to++ = len;
	359
1bc09869	360	if (elapsed_time_len == 2) {
60fe62e7	361	const __be16 var16 = htons((u16)elapsed_time);
1bc09869 IM	362	memcpy(to, &var16, 2);
1bc09869 IM	363	} else {
60fe62e7	364	const __be32 var32 = htonl(elapsed_time);
1bc09869 IM	365	memcpy(to, &var32, 4);
1bc09869 IM	366	}
7c657876	367
2d0817d1	368	return 0;
7c657876 ACM	369	}
7c657876 ACM	370
d4b81ff7	371	EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
7c657876	372
1f4f0f64	373	static int dccp_insert_option_timestamp(struct sk_buff *skb)
7c657876	374	{
4c70f383	375	__be32 now = htonl(dccp_timestamp());
1bc09869 IM	376	/* yes this will overflow but that is the point as we want a
	377	* 10 usec 32 bit timer which mean it wraps every 11.9 hours */
	378
a7d13fbf	379	return dccp_insert_option(skb, DCCPO_TIMESTAMP, &now, sizeof(now));
7c657876 ACM	380	}
7c657876 ACM	381
b4d4f7c7 GR	382	static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp,
b4d4f7c7 GR	383	struct dccp_request_sock *dreq,
2d0817d1	384	struct sk_buff *skb)
7c657876	385	{
60fe62e7	386	__be32 tstamp_echo;
7c657876	387	unsigned char *to;
b4d4f7c7 GR	388	u32 elapsed_time, elapsed_time_len, len;
	389
	390	if (dreq != NULL) {
	391	elapsed_time = dccp_timestamp() - dreq->dreq_timestamp_time;
	392	tstamp_echo = htonl(dreq->dreq_timestamp_echo);
	393	dreq->dreq_timestamp_echo = 0;
	394	} else {
	395	elapsed_time = dccp_timestamp() - dp->dccps_timestamp_time;
	396	tstamp_echo = htonl(dp->dccps_timestamp_echo);
	397	dp->dccps_timestamp_echo = 0;
	398	}
	399
b0e56780 ACM	400	elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
	401	len = 6 + elapsed_time_len;
	402
2d0817d1 ACM	403	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
2d0817d1 ACM	404	return -1;
7c657876 ACM	405
	406	DCCP_SKB_CB(skb)->dccpd_opt_len += len;
	407
	408	to = skb_push(skb, len);
	409	*to++ = DCCPO_TIMESTAMP_ECHO;
	410	*to++ = len;
	411
7c657876 ACM	412	memcpy(to, &tstamp_echo, 4);
7c657876 ACM	413	to += 4;
afe00251	414
1bc09869	415	if (elapsed_time_len == 2) {
60fe62e7	416	const __be16 var16 = htons((u16)elapsed_time);
1bc09869 IM	417	memcpy(to, &var16, 2);
1bc09869 IM	418	} else if (elapsed_time_len == 4) {
60fe62e7	419	const __be32 var32 = htonl(elapsed_time);
1bc09869 IM	420	memcpy(to, &var32, 4);
1bc09869 IM	421	}
7c657876	422
2d0817d1	423	return 0;
7c657876 ACM	424	}
7c657876 ACM	425
7d870936 GR	426	static int dccp_insert_option_ackvec(struct sock sk, struct sk_buff skb)
	427	{
	428	struct dccp_sock *dp = dccp_sk(sk);
	429	struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec;
b3d14bff	430	const u16 buflen = dccp_ackvec_buflen(av);
7d870936	431	/* Figure out how many options do we need to represent the ackvec */
b3d14bff GR	432	const u8 nr_opts = DIV_ROUND_UP(buflen, DCCP_SINGLE_OPT_MAXLEN);
b3d14bff GR	433	u16 len = buflen + 2 * nr_opts;
7d870936 GR	434	u8 i, nonce = 0;
	435	const unsigned char tail, from;
	436	unsigned char *to;
	437
	438	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
	439	return -1;
	440
	441	DCCP_SKB_CB(skb)->dccpd_opt_len += len;
	442
	443	to = skb_push(skb, len);
b3d14bff	444	len = buflen;
7d870936 GR	445	from = av->av_buf + av->av_buf_head;
	446	tail = av->av_buf + DCCPAV_MAX_ACKVEC_LEN;
	447
	448	for (i = 0; i < nr_opts; ++i) {
	449	int copylen = len;
	450
	451	if (len > DCCP_SINGLE_OPT_MAXLEN)
	452	copylen = DCCP_SINGLE_OPT_MAXLEN;
	453
	454	/*
	455	* RFC 4340, 12.2: Encode the Nonce Echo for this Ack Vector via
	456	* its type; ack_nonce is the sum of all individual buf_nonce's.
	457	*/
	458	nonce ^= av->av_buf_nonce[i];
	459
	460	*to++ = DCCPO_ACK_VECTOR_0 + av->av_buf_nonce[i];
	461	*to++ = copylen + 2;
	462
	463	/* Check if buf_head wraps */
	464	if (from + copylen > tail) {
	465	const u16 tailsize = tail - from;
	466
	467	memcpy(to, from, tailsize);
	468	to += tailsize;
	469	len -= tailsize;
	470	copylen -= tailsize;
	471	from = av->av_buf;
	472	}
	473
	474	memcpy(to, from, copylen);
	475	from += copylen;
	476	to += copylen;
	477	len -= copylen;
	478	}
	479	/*
	480	* Each sent Ack Vector is recorded in the list, as per A.2 of RFC 4340.
	481	*/
	482	if (dccp_ackvec_update_records(av, DCCP_SKB_CB(skb)->dccpd_seq, nonce))
	483	return -ENOBUFS;
	484	return 0;
	485	}
	486
d3710566 GR	487	/**
	488	* dccp_insert_option_mandatory - Mandatory option (5.8.2)
	489	* Note that since we are using skb_push, this function needs to be called
	490	* _after_ inserting the option it is supposed to influence (stack order).
	491	*/
	492	int dccp_insert_option_mandatory(struct sk_buff *skb)
	493	{
	494	if (DCCP_SKB_CB(skb)->dccpd_opt_len >= DCCP_MAX_OPT_LEN)
	495	return -1;
	496
	497	DCCP_SKB_CB(skb)->dccpd_opt_len++;
	498	*skb_push(skb, 1) = DCCPO_MANDATORY;
	499	return 0;
	500	}
	501
8c862c23 GR	502	/**
	503	* dccp_insert_fn_opt - Insert single Feature-Negotiation option into @skb
	504	* @type: %DCCPO_CHANGE_L, %DCCPO_CHANGE_R, %DCCPO_CONFIRM_L, %DCCPO_CONFIRM_R
	505	* @feat: one out of %dccp_feature_numbers
	506	* @val: NN value or SP array (preferred element first) to copy
	507	* @len: true length of @val in bytes (excluding first element repetition)
	508	* @repeat_first: whether to copy the first element of @val twice
	509	* The last argument is used to construct Confirm options, where the preferred
	510	* value and the preference list appear separately (RFC 4340, 6.3.1). Preference
	511	* lists are kept such that the preferred entry is always first, so we only need
	512	* to copy twice, and avoid the overhead of cloning into a bigger array.
	513	*/
	514	int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat,
	515	u8 *val, u8 len, bool repeat_first)
4829007c	516	{
8c862c23	517	u8 tot_len, *to;
4829007c	518
8c862c23 GR	519	/* take the `Feature' field and possible repetition into account */
	520	if (len > (DCCP_SINGLE_OPT_MAXLEN - 2)) {
	521	DCCP_WARN("length %u for feature %u too large\n", len, feat);
4829007c	522	return -1;
c2f42077	523	}
4829007c	524
8c862c23 GR	525	if (unlikely(val == NULL \|\| len == 0))
	526	len = repeat_first = 0;
	527	tot_len = 3 + repeat_first + len;
	528
	529	if (DCCP_SKB_CB(skb)->dccpd_opt_len + tot_len > DCCP_MAX_OPT_LEN) {
	530	DCCP_WARN("packet too small for feature %d option!\n", feat);
	531	return -1;
	532	}
	533	DCCP_SKB_CB(skb)->dccpd_opt_len += tot_len;
4829007c	534
8c862c23	535	to = skb_push(skb, tot_len);
410e27a4	536	*to++ = type;
8c862c23	537	*to++ = tot_len;
410e27a4	538	*to++ = feat;
4829007c	539
8c862c23 GR	540	if (repeat_first)
8c862c23 GR	541	to++ = val;
410e27a4 GR	542	if (len)
410e27a4 GR	543	memcpy(to, val, len);
d0440ee6 GR	544	return 0;
	545	}
	546
af3b867e GR	547	/* The length of all options needs to be a multiple of 4 (5.8) */
	548	static void dccp_insert_option_padding(struct sk_buff *skb)
	549	{
	550	int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4;
	551
	552	if (padding != 0) {
	553	padding = 4 - padding;
	554	memset(skb_push(skb, padding), 0, padding);
	555	DCCP_SKB_CB(skb)->dccpd_opt_len += padding;
	556	}
	557	}
	558
2d0817d1	559	int dccp_insert_options(struct sock sk, struct sk_buff skb)
7c657876 ACM	560	{
	561	struct dccp_sock *dp = dccp_sk(sk);
	562
	563	DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
	564
4098dce5	565	if (dp->dccps_send_ndp_count && dccp_insert_option_ndp(sk, skb))
2d0817d1	566	return -1;
7c657876	567
8b7b6c75 GR	568	if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA) {
	569
	570	/* Feature Negotiation */
	571	if (dccp_feat_insert_opts(dp, NULL, skb))
2d0817d1	572	return -1;
8b7b6c75 GR	573
	574	if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST) {
	575	/*
	576	* Obtain RTT sample from Request/Response exchange.
59b80802	577	* This is currently used for TFRC initialisation.
8b7b6c75	578	*/
a7d13fbf	579	if (dccp_insert_option_timestamp(skb))
8b7b6c75 GR	580	return -1;
8b7b6c75 GR	581
b3d14bff	582	} else if (dccp_ackvec_pending(sk) &&
8b7b6c75 GR	583	dccp_insert_option_ackvec(sk, skb)) {
	584	return -1;
	585	}
7c657876 ACM	586	}
7c657876 ACM	587
507d37cf	588	if (dp->dccps_hc_rx_insert_options) {
2d0817d1 ACM	589	if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb))
2d0817d1 ACM	590	return -1;
507d37cf ACM	591	dp->dccps_hc_rx_insert_options = 0;
507d37cf ACM	592	}
7c657876	593
b4d4f7c7 GR	594	if (dp->dccps_timestamp_echo != 0 &&
	595	dccp_insert_option_timestamp_echo(dp, NULL, skb))
	596	return -1;
	597
af3b867e GR	598	dccp_insert_option_padding(skb);
	599	return 0;
	600	}
7c657876	601
af3b867e GR	602	int dccp_insert_options_rsk(struct dccp_request_sock dreq, struct sk_buff skb)
	603	{
	604	DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
7c657876	605
8b7b6c75 GR	606	if (dccp_feat_insert_opts(NULL, dreq, skb))
	607	return -1;
	608
59b80802 GR	609	/* Obtain RTT sample from Response/Ack exchange (used by TFRC). */
	610	if (dccp_insert_option_timestamp(skb))
	611	return -1;
	612
af3b867e GR	613	if (dreq->dreq_timestamp_echo != 0 &&
	614	dccp_insert_option_timestamp_echo(NULL, dreq, skb))
	615	return -1;
2d0817d1	616
af3b867e	617	dccp_insert_option_padding(skb);
2d0817d1	618	return 0;
7c657876	619	}