[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_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_ACK_VECTOR_0:
		case DCCPO_ACK_VECTOR_1:
			if (dccp_packet_without_ack(skb))   /* RFC 4340, 11.4 */
				break;
			/*
			 * Ack vectors are processed by the TX CCID if it is
			 * interested. The RX CCID need not parse Ack Vectors,
			 * since it is only interested in clearing old state.
			 * Fall through.
			 */
		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;
	struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
	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 (dcb->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) {
		DCCP_WARN("Lacking space for %u bytes on %s packet\n", len,
			  dccp_packet_name(dcb->dccpd_type));
		return -1;
	}
	/*
	 * Since Ack Vectors are variable-length, we can not always predict
	 * their size. To catch exception cases where the space is running out
	 * on the skb, a separate Sync is scheduled to carry the Ack Vector.
	 */
	if (len > DCCPAV_MIN_OPTLEN &&
	    len + dcb->dccpd_opt_len + skb->len > dp->dccps_mss_cache) {
		DCCP_WARN("No space left for Ack Vector (%u) on skb (%u+%u), "
			  "MPS=%u ==> reduce payload size?\n", len, skb->len,
			  dcb->dccpd_opt_len, dp->dccps_mss_cache);
		dp->dccps_sync_scheduled = 1;
		return 0;
	}
	dcb->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, dcb->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
	1	/*
	2	* net/dccp/options.c
	3	*
	4	* An implementation of the DCCP protocol
	5	* Copyright (c) 2005 Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
	6	* Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
	7	* Copyright (c) 2005 Ian McDonald <ian.mcdonald@jandi.co.nz>
	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	*/
	14	#include <linux/dccp.h>
	15	#include <linux/module.h>
	16	#include <linux/types.h>
	17	#include <asm/unaligned.h>
	18	#include <linux/kernel.h>
	19	#include <linux/skbuff.h>
	20
	21	#include "ackvec.h"
	22	#include "ccid.h"
	23	#include "dccp.h"
	24	#include "feat.h"
	25
	26	u64 dccp_decode_value_var(const u8 *bf, const u8 len)
	27	{
	28	u64 value = 0;
	29
	30	if (len >= DCCP_OPTVAL_MAXLEN)
	31	value += ((u64)*bf++) << 40;
	32	if (len > 4)
	33	value += ((u64)*bf++) << 32;
	34	if (len > 3)
	35	value += ((u64)*bf++) << 24;
	36	if (len > 2)
	37	value += ((u64)*bf++) << 16;
	38	if (len > 1)
	39	value += ((u64)*bf++) << 8;
	40	if (len > 0)
	41	value += *bf;
	42
	43	return value;
	44	}
	45
	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)
	53	{
	54	struct dccp_sock *dp = dccp_sk(sk);
	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;
	59	const unsigned char opt_end = (unsigned char )dh +
	60	(dh->dccph_doff * 4);
	61	struct dccp_options_received *opt_recv = &dp->dccps_options_received;
	62	unsigned char opt, len;
	63	unsigned char *uninitialized_var(value);
	64	u32 elapsed_time;
	65	__be32 opt_val;
	66	int rc;
	67	int mandatory = 0;
	68
	69	memset(opt_recv, 0, sizeof(*opt_recv));
	70
	71	opt = len = 0;
	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)
	80	goto out_nonsensical_length;
	81
	82	len = *opt_ptr++;
	83	if (len < 2)
	84	goto out_nonsensical_length;
	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)
	94	goto out_nonsensical_length;
	95	}
	96
	97	/*
	98	* CCID-specific options are ignored during connection setup, as
	99	* negotiation may still be in progress (see RFC 4340, 10.3).
	100	* The same applies to Ack Vectors, as these depend on the CCID.
	101	*/
	102	if (dreq != NULL && (opt >= DCCPO_MIN_RX_CCID_SPECIFIC \|\|
	103	opt == DCCPO_ACK_VECTOR_0 \|\| opt == DCCPO_ACK_VECTOR_1))
	104	goto ignore_option;
	105
	106	switch (opt) {
	107	case DCCPO_PADDING:
	108	break;
	109	case DCCPO_MANDATORY:
	110	if (mandatory)
	111	goto out_invalid_option;
	112	if (pkt_type != DCCP_PKT_DATA)
	113	mandatory = 1;
	114	break;
	115	case DCCPO_NDP_COUNT:
	116	if (len > 6)
	117	goto out_invalid_option;
	118
	119	opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
	120	dccp_pr_debug("%s opt: NDP count=%llu\n", dccp_role(sk),
	121	(unsigned long long)opt_recv->dccpor_ndp);
	122	break;
	123	case DCCPO_CHANGE_L ... DCCPO_CONFIRM_R:
	124	if (pkt_type == DCCP_PKT_DATA) /* RFC 4340, 6 */
	125	break;
	126	rc = dccp_feat_parse_options(sk, dreq, mandatory, opt,
	127	*value, value + 1, len - 1);
	128	if (rc)
	129	goto out_featneg_failed;
	130	break;
	131	case DCCPO_TIMESTAMP:
	132	if (len != 4)
	133	goto out_invalid_option;
	134	/*
	135	* RFC 4340 13.1: "The precise time corresponding to
	136	* Timestamp Value zero is not specified". We use
	137	* zero to indicate absence of a meaningful timestamp.
	138	*/
	139	opt_val = get_unaligned((__be32 *)value);
	140	if (unlikely(opt_val == 0)) {
	141	DCCP_WARN("Timestamp with zero value\n");
	142	break;
	143	}
	144
	145	if (dreq != NULL) {
	146	dreq->dreq_timestamp_echo = ntohl(opt_val);
	147	dreq->dreq_timestamp_time = dccp_timestamp();
	148	} else {
	149	opt_recv->dccpor_timestamp =
	150	dp->dccps_timestamp_echo = ntohl(opt_val);
	151	dp->dccps_timestamp_time = dccp_timestamp();
	152	}
	153	dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n",
	154	dccp_role(sk), ntohl(opt_val),
	155	(unsigned long long)
	156	DCCP_SKB_CB(skb)->dccpd_ack_seq);
	157	/* schedule an Ack in case this sender is quiescent */
	158	inet_csk_schedule_ack(sk);
	159	break;
	160	case DCCPO_TIMESTAMP_ECHO:
	161	if (len != 4 && len != 6 && len != 8)
	162	goto out_invalid_option;
	163
	164	opt_val = get_unaligned((__be32 *)value);
	165	opt_recv->dccpor_timestamp_echo = ntohl(opt_val);
	166
	167	dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, "
	168	"ackno=%llu", dccp_role(sk),
	169	opt_recv->dccpor_timestamp_echo,
	170	len + 2,
	171	(unsigned long long)
	172	DCCP_SKB_CB(skb)->dccpd_ack_seq);
	173
	174	value += 4;
	175
	176	if (len == 4) { /* no elapsed time included */
	177	dccp_pr_debug_cat("\n");
	178	break;
	179	}
	180
	181	if (len == 6) { /* 2-byte elapsed time */
	182	__be16 opt_val2 = get_unaligned((__be16 *)value);
	183	elapsed_time = ntohs(opt_val2);
	184	} else { /* 4-byte elapsed time */
	185	opt_val = get_unaligned((__be32 *)value);
	186	elapsed_time = ntohl(opt_val);
	187	}
	188
	189	dccp_pr_debug_cat(", ELAPSED_TIME=%u\n", elapsed_time);
	190
	191	/* Give precedence to the biggest ELAPSED_TIME */
	192	if (elapsed_time > opt_recv->dccpor_elapsed_time)
	193	opt_recv->dccpor_elapsed_time = elapsed_time;
	194	break;
	195	case DCCPO_ELAPSED_TIME:
	196	if (dccp_packet_without_ack(skb)) /* RFC 4340, 13.2 */
	197	break;
	198
	199	if (len == 2) {
	200	__be16 opt_val2 = get_unaligned((__be16 *)value);
	201	elapsed_time = ntohs(opt_val2);
	202	} else if (len == 4) {
	203	opt_val = get_unaligned((__be32 *)value);
	204	elapsed_time = ntohl(opt_val);
	205	} else {
	206	goto out_invalid_option;
	207	}
	208
	209	if (elapsed_time > opt_recv->dccpor_elapsed_time)
	210	opt_recv->dccpor_elapsed_time = elapsed_time;
	211
	212	dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n",
	213	dccp_role(sk), elapsed_time);
	214	break;
	215	case DCCPO_MIN_RX_CCID_SPECIFIC ... DCCPO_MAX_RX_CCID_SPECIFIC:
	216	if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
	217	pkt_type, opt, value, len))
	218	goto out_invalid_option;
	219	break;
	220	case DCCPO_ACK_VECTOR_0:
	221	case DCCPO_ACK_VECTOR_1:
	222	if (dccp_packet_without_ack(skb)) /* RFC 4340, 11.4 */
	223	break;
	224	/*
	225	* Ack vectors are processed by the TX CCID if it is
	226	* interested. The RX CCID need not parse Ack Vectors,
	227	* since it is only interested in clearing old state.
	228	* Fall through.
	229	*/
	230	case DCCPO_MIN_TX_CCID_SPECIFIC ... DCCPO_MAX_TX_CCID_SPECIFIC:
	231	if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
	232	pkt_type, opt, value, len))
	233	goto out_invalid_option;
	234	break;
	235	default:
	236	DCCP_CRIT("DCCP(%p): option %d(len=%d) not "
	237	"implemented, ignoring", sk, opt, len);
	238	break;
	239	}
	240	ignore_option:
	241	if (opt != DCCPO_MANDATORY)
	242	mandatory = 0;
	243	}
	244
	245	/* mandatory was the last byte in option list -> reset connection */
	246	if (mandatory)
	247	goto out_invalid_option;
	248
	249	out_nonsensical_length:
	250	/* RFC 4340, 5.8: ignore option and all remaining option space */
	251	return 0;
	252
	253	out_invalid_option:
	254	DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
	255	rc = DCCP_RESET_CODE_OPTION_ERROR;
	256	out_featneg_failed:
	257	DCCP_WARN("DCCP(%p): Option %d (len=%d) error=%u\n", sk, opt, len, rc);
	258	DCCP_SKB_CB(skb)->dccpd_reset_code = rc;
	259	DCCP_SKB_CB(skb)->dccpd_reset_data[0] = opt;
	260	DCCP_SKB_CB(skb)->dccpd_reset_data[1] = len > 0 ? value[0] : 0;
	261	DCCP_SKB_CB(skb)->dccpd_reset_data[2] = len > 1 ? value[1] : 0;
	262	return -1;
	263	}
	264
	265	EXPORT_SYMBOL_GPL(dccp_parse_options);
	266
	267	void dccp_encode_value_var(const u64 value, u8 *to, const u8 len)
	268	{
	269	if (len >= DCCP_OPTVAL_MAXLEN)
	270	*to++ = (value & 0xFF0000000000ull) >> 40;
	271	if (len > 4)
	272	*to++ = (value & 0xFF00000000ull) >> 32;
	273	if (len > 3)
	274	*to++ = (value & 0xFF000000) >> 24;
	275	if (len > 2)
	276	*to++ = (value & 0xFF0000) >> 16;
	277	if (len > 1)
	278	*to++ = (value & 0xFF00) >> 8;
	279	if (len > 0)
	280	*to++ = (value & 0xFF);
	281	}
	282
	283	static inline u8 dccp_ndp_len(const u64 ndp)
	284	{
	285	if (likely(ndp <= 0xFF))
	286	return 1;
	287	return likely(ndp <= USHRT_MAX) ? 2 : (ndp <= UINT_MAX ? 4 : 6);
	288	}
	289
	290	int dccp_insert_option(struct sk_buff *skb, const unsigned char option,
	291	const void *value, const unsigned char len)
	292	{
	293	unsigned char *to;
	294
	295	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN)
	296	return -1;
	297
	298	DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
	299
	300	to = skb_push(skb, len + 2);
	301	*to++ = option;
	302	*to++ = len + 2;
	303
	304	memcpy(to, value, len);
	305	return 0;
	306	}
	307
	308	EXPORT_SYMBOL_GPL(dccp_insert_option);
	309
	310	static int dccp_insert_option_ndp(struct sock sk, struct sk_buff skb)
	311	{
	312	struct dccp_sock *dp = dccp_sk(sk);
	313	u64 ndp = dp->dccps_ndp_count;
	314
	315	if (dccp_non_data_packet(skb))
	316	++dp->dccps_ndp_count;
	317	else
	318	dp->dccps_ndp_count = 0;
	319
	320	if (ndp > 0) {
	321	unsigned char *ptr;
	322	const int ndp_len = dccp_ndp_len(ndp);
	323	const int len = ndp_len + 2;
	324
	325	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
	326	return -1;
	327
	328	DCCP_SKB_CB(skb)->dccpd_opt_len += len;
	329
	330	ptr = skb_push(skb, len);
	331	*ptr++ = DCCPO_NDP_COUNT;
	332	*ptr++ = len;
	333	dccp_encode_value_var(ndp, ptr, ndp_len);
	334	}
	335
	336	return 0;
	337	}
	338
	339	static inline int dccp_elapsed_time_len(const u32 elapsed_time)
	340	{
	341	return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
	342	}
	343
	344	/* FIXME: This function is currently not used anywhere */
	345	int dccp_insert_option_elapsed_time(struct sk_buff *skb, u32 elapsed_time)
	346	{
	347	const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
	348	const int len = 2 + elapsed_time_len;
	349	unsigned char *to;
	350
	351	if (elapsed_time_len == 0)
	352	return 0;
	353
	354	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
	355	return -1;
	356
	357	DCCP_SKB_CB(skb)->dccpd_opt_len += len;
	358
	359	to = skb_push(skb, len);
	360	*to++ = DCCPO_ELAPSED_TIME;
	361	*to++ = len;
	362
	363	if (elapsed_time_len == 2) {
	364	const __be16 var16 = htons((u16)elapsed_time);
	365	memcpy(to, &var16, 2);
	366	} else {
	367	const __be32 var32 = htonl(elapsed_time);
	368	memcpy(to, &var32, 4);
	369	}
	370
	371	return 0;
	372	}
	373
	374	EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
	375
	376	static int dccp_insert_option_timestamp(struct sk_buff *skb)
	377	{
	378	__be32 now = htonl(dccp_timestamp());
	379	/* yes this will overflow but that is the point as we want a
	380	* 10 usec 32 bit timer which mean it wraps every 11.9 hours */
	381
	382	return dccp_insert_option(skb, DCCPO_TIMESTAMP, &now, sizeof(now));
	383	}
	384
	385	static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp,
	386	struct dccp_request_sock *dreq,
	387	struct sk_buff *skb)
	388	{
	389	__be32 tstamp_echo;
	390	unsigned char *to;
	391	u32 elapsed_time, elapsed_time_len, len;
	392
	393	if (dreq != NULL) {
	394	elapsed_time = dccp_timestamp() - dreq->dreq_timestamp_time;
	395	tstamp_echo = htonl(dreq->dreq_timestamp_echo);
	396	dreq->dreq_timestamp_echo = 0;
	397	} else {
	398	elapsed_time = dccp_timestamp() - dp->dccps_timestamp_time;
	399	tstamp_echo = htonl(dp->dccps_timestamp_echo);
	400	dp->dccps_timestamp_echo = 0;
	401	}
	402
	403	elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
	404	len = 6 + elapsed_time_len;
	405
	406	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
	407	return -1;
	408
	409	DCCP_SKB_CB(skb)->dccpd_opt_len += len;
	410
	411	to = skb_push(skb, len);
	412	*to++ = DCCPO_TIMESTAMP_ECHO;
	413	*to++ = len;
	414
	415	memcpy(to, &tstamp_echo, 4);
	416	to += 4;
	417
	418	if (elapsed_time_len == 2) {
	419	const __be16 var16 = htons((u16)elapsed_time);
	420	memcpy(to, &var16, 2);
	421	} else if (elapsed_time_len == 4) {
	422	const __be32 var32 = htonl(elapsed_time);
	423	memcpy(to, &var32, 4);
	424	}
	425
	426	return 0;
	427	}
	428
	429	static int dccp_insert_option_ackvec(struct sock sk, struct sk_buff skb)
	430	{
	431	struct dccp_sock *dp = dccp_sk(sk);
	432	struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec;
	433	struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
	434	const u16 buflen = dccp_ackvec_buflen(av);
	435	/* Figure out how many options do we need to represent the ackvec */
	436	const u8 nr_opts = DIV_ROUND_UP(buflen, DCCP_SINGLE_OPT_MAXLEN);
	437	u16 len = buflen + 2 * nr_opts;
	438	u8 i, nonce = 0;
	439	const unsigned char tail, from;
	440	unsigned char *to;
	441
	442	if (dcb->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) {
	443	DCCP_WARN("Lacking space for %u bytes on %s packet\n", len,
	444	dccp_packet_name(dcb->dccpd_type));
	445	return -1;
	446	}
	447	/*
	448	* Since Ack Vectors are variable-length, we can not always predict
	449	* their size. To catch exception cases where the space is running out
	450	* on the skb, a separate Sync is scheduled to carry the Ack Vector.
	451	*/
	452	if (len > DCCPAV_MIN_OPTLEN &&
	453	len + dcb->dccpd_opt_len + skb->len > dp->dccps_mss_cache) {
	454	DCCP_WARN("No space left for Ack Vector (%u) on skb (%u+%u), "
	455	"MPS=%u ==> reduce payload size?\n", len, skb->len,
	456	dcb->dccpd_opt_len, dp->dccps_mss_cache);
	457	dp->dccps_sync_scheduled = 1;
	458	return 0;
	459	}
	460	dcb->dccpd_opt_len += len;
	461
	462	to = skb_push(skb, len);
	463	len = buflen;
	464	from = av->av_buf + av->av_buf_head;
	465	tail = av->av_buf + DCCPAV_MAX_ACKVEC_LEN;
	466
	467	for (i = 0; i < nr_opts; ++i) {
	468	int copylen = len;
	469
	470	if (len > DCCP_SINGLE_OPT_MAXLEN)
	471	copylen = DCCP_SINGLE_OPT_MAXLEN;
	472
	473	/*
	474	* RFC 4340, 12.2: Encode the Nonce Echo for this Ack Vector via
	475	* its type; ack_nonce is the sum of all individual buf_nonce's.
	476	*/
	477	nonce ^= av->av_buf_nonce[i];
	478
	479	*to++ = DCCPO_ACK_VECTOR_0 + av->av_buf_nonce[i];
	480	*to++ = copylen + 2;
	481
	482	/* Check if buf_head wraps */
	483	if (from + copylen > tail) {
	484	const u16 tailsize = tail - from;
	485
	486	memcpy(to, from, tailsize);
	487	to += tailsize;
	488	len -= tailsize;
	489	copylen -= tailsize;
	490	from = av->av_buf;
	491	}
	492
	493	memcpy(to, from, copylen);
	494	from += copylen;
	495	to += copylen;
	496	len -= copylen;
	497	}
	498	/*
	499	* Each sent Ack Vector is recorded in the list, as per A.2 of RFC 4340.
	500	*/
	501	if (dccp_ackvec_update_records(av, dcb->dccpd_seq, nonce))
	502	return -ENOBUFS;
	503	return 0;
	504	}
	505
	506	/**
	507	* dccp_insert_option_mandatory - Mandatory option (5.8.2)
	508	* Note that since we are using skb_push, this function needs to be called
	509	* _after_ inserting the option it is supposed to influence (stack order).
	510	*/
	511	int dccp_insert_option_mandatory(struct sk_buff *skb)
	512	{
	513	if (DCCP_SKB_CB(skb)->dccpd_opt_len >= DCCP_MAX_OPT_LEN)
	514	return -1;
	515
	516	DCCP_SKB_CB(skb)->dccpd_opt_len++;
	517	*skb_push(skb, 1) = DCCPO_MANDATORY;
	518	return 0;
	519	}
	520
	521	/**
	522	* dccp_insert_fn_opt - Insert single Feature-Negotiation option into @skb
	523	* @type: %DCCPO_CHANGE_L, %DCCPO_CHANGE_R, %DCCPO_CONFIRM_L, %DCCPO_CONFIRM_R
	524	* @feat: one out of %dccp_feature_numbers
	525	* @val: NN value or SP array (preferred element first) to copy
	526	* @len: true length of @val in bytes (excluding first element repetition)
	527	* @repeat_first: whether to copy the first element of @val twice
	528	* The last argument is used to construct Confirm options, where the preferred
	529	* value and the preference list appear separately (RFC 4340, 6.3.1). Preference
	530	* lists are kept such that the preferred entry is always first, so we only need
	531	* to copy twice, and avoid the overhead of cloning into a bigger array.
	532	*/
	533	int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat,
	534	u8 *val, u8 len, bool repeat_first)
	535	{
	536	u8 tot_len, *to;
	537
	538	/* take the `Feature' field and possible repetition into account */
	539	if (len > (DCCP_SINGLE_OPT_MAXLEN - 2)) {
	540	DCCP_WARN("length %u for feature %u too large\n", len, feat);
	541	return -1;
	542	}
	543
	544	if (unlikely(val == NULL \|\| len == 0))
	545	len = repeat_first = 0;
	546	tot_len = 3 + repeat_first + len;
	547
	548	if (DCCP_SKB_CB(skb)->dccpd_opt_len + tot_len > DCCP_MAX_OPT_LEN) {
	549	DCCP_WARN("packet too small for feature %d option!\n", feat);
	550	return -1;
	551	}
	552	DCCP_SKB_CB(skb)->dccpd_opt_len += tot_len;
	553
	554	to = skb_push(skb, tot_len);
	555	*to++ = type;
	556	*to++ = tot_len;
	557	*to++ = feat;
	558
	559	if (repeat_first)
	560	to++ = val;
	561	if (len)
	562	memcpy(to, val, len);
	563	return 0;
	564	}
	565
	566	/* The length of all options needs to be a multiple of 4 (5.8) */
	567	static void dccp_insert_option_padding(struct sk_buff *skb)
	568	{
	569	int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4;
	570
	571	if (padding != 0) {
	572	padding = 4 - padding;
	573	memset(skb_push(skb, padding), 0, padding);
	574	DCCP_SKB_CB(skb)->dccpd_opt_len += padding;
	575	}
	576	}
	577
	578	int dccp_insert_options(struct sock sk, struct sk_buff skb)
	579	{
	580	struct dccp_sock *dp = dccp_sk(sk);
	581
	582	DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
	583
	584	if (dp->dccps_send_ndp_count && dccp_insert_option_ndp(sk, skb))
	585	return -1;
	586
	587	if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA) {
	588
	589	/* Feature Negotiation */
	590	if (dccp_feat_insert_opts(dp, NULL, skb))
	591	return -1;
	592
	593	if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST) {
	594	/*
	595	* Obtain RTT sample from Request/Response exchange.
	596	* This is currently used for TFRC initialisation.
	597	*/
	598	if (dccp_insert_option_timestamp(skb))
	599	return -1;
	600
	601	} else if (dccp_ackvec_pending(sk) &&
	602	dccp_insert_option_ackvec(sk, skb)) {
	603	return -1;
	604	}
	605	}
	606
	607	if (dp->dccps_hc_rx_insert_options) {
	608	if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb))
	609	return -1;
	610	dp->dccps_hc_rx_insert_options = 0;
	611	}
	612
	613	if (dp->dccps_timestamp_echo != 0 &&
	614	dccp_insert_option_timestamp_echo(dp, NULL, skb))
	615	return -1;
	616
	617	dccp_insert_option_padding(skb);
	618	return 0;
	619	}
	620
	621	int dccp_insert_options_rsk(struct dccp_request_sock dreq, struct sk_buff skb)
	622	{
	623	DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
	624
	625	if (dccp_feat_insert_opts(NULL, dreq, skb))
	626	return -1;
	627
	628	/* Obtain RTT sample from Response/Ack exchange (used by TFRC). */
	629	if (dccp_insert_option_timestamp(skb))
	630	return -1;
	631
	632	if (dreq->dreq_timestamp_echo != 0 &&
	633	dccp_insert_option_timestamp_echo(NULL, dreq, skb))
	634	return -1;
	635
	636	dccp_insert_option_padding(skb);
	637	return 0;
	638	}