net: Retire DCCP socket.

DCCP was orphaned in 2021 by commit 054c4610bd05 ("MAINTAINERS: dccp:
move Gerrit Renker to CREDITS"), which noted that the last maintainer
had been inactive for five years.

In recent years, it has become a playground for syzbot, and most changes
to DCCP have been odd bug fixes triggered by syzbot.  Apart from that,
the only changes have been driven by treewide or networking API updates
or adjustments related to TCP.

Thus, in 2023, we announced we would remove DCCP in 2025 via commit
b144fcaf46d4 ("dccp: Print deprecation notice.").

Since then, only one individual has contacted the netdev mailing list. [0]

There is ongoing research for Multipath DCCP.  The repository is hosted
on GitHub [1], and development is not taking place through the upstream
community.  While the repository is published under the GPLv2 license,
the scheduling part remains proprietary, with a LICENSE file [2] stating:

  "This is not Open Source software."

The researcher mentioned a plan to address the licensing issue, upstream
the patches, and step up as a maintainer, but there has been no further
communication since then.

Maintaining DCCP for a decade without any real users has become a burden.

Therefore, it's time to remove it.

Removing DCCP will also provide significant benefits to TCP.  It allows
us to freely reorganize the layout of struct inet_connection_sock, which
is currently shared with DCCP, and optimize it to reduce the number of
cachelines accessed in the TCP fast path.

Note that we keep DCCP netfilter modules as requested.  [3]

Link: https://lore.kernel.org/netdev/20230710182253.81446-1-kuniyu@amazon.com/T/#u #[0]
Link: https://github.com/telekom/mp-dccp #[1]
Link: https://github.com/telekom/mp-dccp/blob/mpdccp_v03_k5.10/net/dccp/non_gpl_scheduler/LICENSE #[2]
Link: https://lore.kernel.org/netdev/Z_VQ0KlCRkqYWXa-@calendula/ #[3]
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paul Moore <paul@paul-moore.com> (LSM and SELinux)
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Link: https://patch.msgid.link/20250410023921.11307-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 0 insertions, 609 deletions

diff --git a/net/dccp/options.c b/net/dccp/options.c
deleted file mode 100644
index db62d4767024..000000000000
--- a/net/dccp/options.c
+++ /dev/null
@@ -1,609 +0,0 @@
-// 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 <aris@cathedrallabs.org>
- *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
- *  Copyright (c) 2005 Ian McDonald <ian.mcdonald@jandi.co.nz>
- */
-#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)
-{
-	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
- * @skb: frame to parse
- */
-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 *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;
-			if (len == 0)
-				goto out_invalid_option;
-			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.
-			 */
-			fallthrough;
-		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(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;
-}
-
-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)
- * @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)
-{
-	if (DCCP_SKB_CB(skb)->dccpd_opt_len >= DCCP_MAX_OPT_LEN)
-		return -1;
-
-	DCCP_SKB_CB(skb)->dccpd_opt_len++;
-	*(u8 *)skb_push(skb, 1) = DCCPO_MANDATORY;
-	return 0;
-}
-
-/**
- * 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)
-{
-	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 = false;
-	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;
-}