[deliverable/linux.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"

int sysctl_dccp_feat_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW;
int sysctl_dccp_feat_rx_ccid	      = DCCPF_INITIAL_CCID;
int sysctl_dccp_feat_tx_ccid	      = DCCPF_INITIAL_CCID;
int sysctl_dccp_feat_ack_ratio	      = DCCPF_INITIAL_ACK_RATIO;
int sysctl_dccp_feat_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR;
int sysctl_dccp_feat_send_ndp_count  = DCCPF_INITIAL_SEND_NDP_COUNT;

static u32 dccp_decode_value_var(const unsigned char *bf, const u8 len)
{
	u32 value = 0;

	if (len > 3)
		value += *bf++ << 24;
	if (len > 2)
		value += *bf++ << 16;
	if (len > 1)
		value += *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;
	u64 ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq;
	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_invalid_option;

			len = *opt_ptr++;
			if (len < 3)
				goto out_invalid_option;
			/*
			 * 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_invalid_option;
		}

		/*
		 * CCID-Specific Options (from RFC 4340, sec. 10.3):
		 *
		 * Option numbers 128 through 191 are for options sent from the
		 * HC-Sender to the HC-Receiver; option numbers 192 through 255
		 * are for options sent from the HC-Receiver to	the HC-Sender.
		 *
		 * CCID-specific options are ignored during connection setup, as
		 * negotiation may still be in progress (see RFC 4340, 10.3).
		 *
		 */
		if (dreq != NULL && opt >= 128)
			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 > 3)
				goto out_invalid_option;

			opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
			dccp_pr_debug("%s rx opt: NDP count=%d\n", dccp_role(sk),
				      opt_recv->dccpor_ndp);
			break;
		case DCCPO_CHANGE_L:
			/* fall through */
		case DCCPO_CHANGE_R:
			if (len < 2)
				goto out_invalid_option;
			rc = dccp_feat_change_recv(sk, opt, *value, value + 1,
						   len - 1);
			/*
			 * When there is a change error, change_recv is
			 * responsible for dealing with it.  i.e. reply with an
			 * empty confirm.
			 * If the change was mandatory, then we need to die.
			 */
			if (rc && mandatory)
				goto out_invalid_option;
			break;
		case DCCPO_CONFIRM_L:
			/* fall through */
		case DCCPO_CONFIRM_R:
			if (len < 2)
				goto out_invalid_option;
			if (dccp_feat_confirm_recv(sk, opt, *value,
						   value + 1, len - 1))
				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;

			if (dccp_msk(sk)->dccpms_send_ack_vector &&
			    dccp_ackvec_parse(sk, skb, &ackno, opt, value, len))
				goto out_invalid_option;
			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);
			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 128 ... 191: {
			const u16 idx = value - options;

			if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
						     opt, len, idx,
						     value) != 0)
				goto out_invalid_option;
		}
			break;
		case 192 ... 255: {
			const u16 idx = value - options;

			if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
						     opt, len, idx,
						     value) != 0)
				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;

	return 0;

out_invalid_option:
	DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
	DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_OPTION_ERROR;
	DCCP_WARN("DCCP(%p): invalid option %d, len=%d", sk, opt, len);
	return -1;
}

EXPORT_SYMBOL_GPL(dccp_parse_options);

static void dccp_encode_value_var(const u32 value, unsigned char *to,
				  const unsigned int len)
{
	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 int dccp_ndp_len(const int ndp)
{
	return likely(ndp <= 0xFF) ? 1 : ndp <= 0xFFFF ? 2 : 3;
}

int dccp_insert_option(struct sock *sk, 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);
	int 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;
}

int dccp_insert_option_elapsed_time(struct sock *sk, 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);

int dccp_insert_option_timestamp(struct sock *sk, 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(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
}

EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp);

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_feat_opt(struct sk_buff *skb, u8 type, u8 feat,
				u8 *val, u8 len)
{
	u8 *to;

	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 3 > DCCP_MAX_OPT_LEN) {
		DCCP_WARN("packet too small for feature %d option!\n", feat);
		return -1;
	}

	DCCP_SKB_CB(skb)->dccpd_opt_len += len + 3;

	to    = skb_push(skb, len + 3);
	*to++ = type;
	*to++ = len + 3;
	*to++ = feat;

	if (len)
		memcpy(to, val, len);

	dccp_pr_debug("%s(%s (%d), ...), length %d\n",
		      dccp_feat_typename(type),
		      dccp_feat_name(feat), feat, len);
	return 0;
}

static int dccp_insert_options_feat(struct sock *sk, struct sk_buff *skb)
{
	struct dccp_sock *dp = dccp_sk(sk);
	struct dccp_minisock *dmsk = dccp_msk(sk);
	struct dccp_opt_pend *opt, *next;
	int change = 0;

	/* confirm any options [NN opts] */
	list_for_each_entry_safe(opt, next, &dmsk->dccpms_conf, dccpop_node) {
		dccp_insert_feat_opt(skb, opt->dccpop_type,
				     opt->dccpop_feat, opt->dccpop_val,
				     opt->dccpop_len);
		/* fear empty confirms */
		if (opt->dccpop_val)
			kfree(opt->dccpop_val);
		kfree(opt);
	}
	INIT_LIST_HEAD(&dmsk->dccpms_conf);

	/* see which features we need to send */
	list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
		/* see if we need to send any confirm */
		if (opt->dccpop_sc) {
			dccp_insert_feat_opt(skb, opt->dccpop_type + 1,
					     opt->dccpop_feat,
					     opt->dccpop_sc->dccpoc_val,
					     opt->dccpop_sc->dccpoc_len);

			BUG_ON(!opt->dccpop_sc->dccpoc_val);
			kfree(opt->dccpop_sc->dccpoc_val);
			kfree(opt->dccpop_sc);
			opt->dccpop_sc = NULL;
		}

		/* any option not confirmed, re-send it */
		if (!opt->dccpop_conf) {
			dccp_insert_feat_opt(skb, opt->dccpop_type,
					     opt->dccpop_feat, opt->dccpop_val,
					     opt->dccpop_len);
			change++;
		}
	}

	/* Retransmit timer.
	 * If this is the master listening sock, we don't set a timer on it.  It
	 * should be fine because if the dude doesn't receive our RESPONSE
	 * [which will contain the CHANGE] he will send another REQUEST which
	 * will "retrnasmit" the change.
	 */
	if (change && dp->dccps_role != DCCP_ROLE_LISTEN) {
		dccp_pr_debug("reset feat negotiation timer %p\n", sk);

		/* XXX don't reset the timer on re-transmissions.  I.e. reset it
		 * only when sending new stuff i guess.  Currently the timer
		 * never backs off because on re-transmission it just resets it!
		 */
		inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
					  inet_csk(sk)->icsk_rto, DCCP_RTO_MAX);
	}

	return 0;
}

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

	DCCP_SKB_CB(skb)->dccpd_opt_len = 0;

	if (dmsk->dccpms_send_ndp_count &&
	    dccp_insert_option_ndp(sk, skb))
		return -1;

	if (!dccp_packet_without_ack(skb)) {
		if (dmsk->dccpms_send_ack_vector &&
		    dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) &&
		    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;
	}

	/* Feature negotiation */
	/* Data packets can't do feat negotiation */
	if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA &&
	    DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATAACK &&
	    dccp_insert_options_feat(sk, skb))
		return -1;

	/*
	 * Obtain RTT sample from Request/Response exchange.
	 * This is currently used in CCID 3 initialisation.
	 */
	if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST &&
	    dccp_insert_option_timestamp(sk, skb))
		return -1;

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

	/* XXX: insert other options when appropriate */

	if (DCCP_SKB_CB(skb)->dccpd_opt_len != 0) {
		/* The length of all options has to be a multiple of 4 */
		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;
		}
	}

	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
afb0a34d GR	26	int sysctl_dccp_feat_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW;
	27	int sysctl_dccp_feat_rx_ccid = DCCPF_INITIAL_CCID;
	28	int sysctl_dccp_feat_tx_ccid = DCCPF_INITIAL_CCID;
	29	int sysctl_dccp_feat_ack_ratio = DCCPF_INITIAL_ACK_RATIO;
	30	int sysctl_dccp_feat_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR;
	31	int sysctl_dccp_feat_send_ndp_count = DCCPF_INITIAL_SEND_NDP_COUNT;
7c657876	32
7c657876 ACM	33	static u32 dccp_decode_value_var(const unsigned char *bf, const u8 len)
	34	{
	35	u32 value = 0;
	36
	37	if (len > 3)
	38	value += *bf++ << 24;
	39	if (len > 2)
	40	value += *bf++ << 16;
	41	if (len > 1)
	42	value += *bf++ << 8;
	43	if (len > 0)
	44	value += *bf;
	45
	46	return value;
	47	}
	48
8b819412 GR	49	/**
	50	* dccp_parse_options - Parse DCCP options present in @skb
	51	* @sk: client\|server\|listening dccp socket (when @dreq != NULL)
	52	* @dreq: request socket to use during connection setup, or NULL
	53	*/
	54	int dccp_parse_options(struct sock sk, struct dccp_request_sock dreq,
	55	struct sk_buff *skb)
7c657876 ACM	56	{
7c657876 ACM	57	struct dccp_sock *dp = dccp_sk(sk);
7c657876 ACM	58	const struct dccp_hdr *dh = dccp_hdr(skb);
7c657876 ACM	59	const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type;
bdf13d20	60	u64 ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq;
7c657876 ACM	61	unsigned char options = (unsigned char )dh + dccp_hdr_len(skb);
7c657876 ACM	62	unsigned char *opt_ptr = options;
7690af3f ACM	63	const unsigned char opt_end = (unsigned char )dh +
7690af3f ACM	64	(dh->dccph_doff * 4);
7c657876 ACM	65	struct dccp_options_received *opt_recv = &dp->dccps_options_received;
	66	unsigned char opt, len;
	67	unsigned char *value;
1c14ac0a	68	u32 elapsed_time;
76fd1e87	69	__be32 opt_val;
afe00251 AB	70	int rc;
afe00251 AB	71	int mandatory = 0;
7c657876 ACM	72
	73	memset(opt_recv, 0, sizeof(*opt_recv));
	74
fb950496	75	opt = len = 0;
7c657876 ACM	76	while (opt_ptr != opt_end) {
	77	opt = *opt_ptr++;
	78	len = 0;
	79	value = NULL;
	80
	81	/* Check if this isn't a single byte option */
	82	if (opt > DCCPO_MAX_RESERVED) {
	83	if (opt_ptr == opt_end)
	84	goto out_invalid_option;
	85
	86	len = *opt_ptr++;
	87	if (len < 3)
	88	goto out_invalid_option;
	89	/*
	90	* Remove the type and len fields, leaving
	91	* just the value size
	92	*/
	93	len -= 2;
	94	value = opt_ptr;
	95	opt_ptr += len;
	96
	97	if (opt_ptr > opt_end)
	98	goto out_invalid_option;
	99	}
	100
8b819412 GR	101	/*
	102	* CCID-Specific Options (from RFC 4340, sec. 10.3):
	103	*
	104	* Option numbers 128 through 191 are for options sent from the
	105	* HC-Sender to the HC-Receiver; option numbers 192 through 255
	106	* are for options sent from the HC-Receiver to the HC-Sender.
	107	*
	108	* CCID-specific options are ignored during connection setup, as
	109	* negotiation may still be in progress (see RFC 4340, 10.3).
	110	*
	111	*/
	112	if (dreq != NULL && opt >= 128)
	113	goto ignore_option;
	114
7c657876 ACM	115	switch (opt) {
	116	case DCCPO_PADDING:
	117	break;
afe00251 AB	118	case DCCPO_MANDATORY:
	119	if (mandatory)
	120	goto out_invalid_option;
6df9424a ACM	121	if (pkt_type != DCCP_PKT_DATA)
6df9424a ACM	122	mandatory = 1;
afe00251	123	break;
7c657876 ACM	124	case DCCPO_NDP_COUNT:
	125	if (len > 3)
	126	goto out_invalid_option;
	127
	128	opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
09dbc389	129	dccp_pr_debug("%s rx opt: NDP count=%d\n", dccp_role(sk),
7690af3f	130	opt_recv->dccpor_ndp);
7c657876	131	break;
afe00251 AB	132	case DCCPO_CHANGE_L:
	133	/* fall through */
	134	case DCCPO_CHANGE_R:
	135	if (len < 2)
	136	goto out_invalid_option;
	137	rc = dccp_feat_change_recv(sk, opt, *value, value + 1,
	138	len - 1);
	139	/*
	140	* When there is a change error, change_recv is
	141	* responsible for dealing with it. i.e. reply with an
	142	* empty confirm.
	143	* If the change was mandatory, then we need to die.
	144	*/
	145	if (rc && mandatory)
	146	goto out_invalid_option;
	147	break;
	148	case DCCPO_CONFIRM_L:
	149	/* fall through */
	150	case DCCPO_CONFIRM_R:
	151	if (len < 2)
	152	goto out_invalid_option;
	153	if (dccp_feat_confirm_recv(sk, opt, *value,
	154	value + 1, len - 1))
	155	goto out_invalid_option;
	156	break;
7c657876	157	case DCCPO_ACK_VECTOR_0:
ae31c339	158	case DCCPO_ACK_VECTOR_1:
c86ab2b6	159	if (dccp_packet_without_ack(skb)) /* RFC 4340, 11.4 */
e5a6de91	160	break;
7c657876	161
a4bf3902	162	if (dccp_msk(sk)->dccpms_send_ack_vector &&
bdf13d20	163	dccp_ackvec_parse(sk, skb, &ackno, opt, value, len))
ae31c339	164	goto out_invalid_option;
7c657876 ACM	165	break;
	166	case DCCPO_TIMESTAMP:
	167	if (len != 4)
	168	goto out_invalid_option;
b4d4f7c7 GR	169	/*
	170	* RFC 4340 13.1: "The precise time corresponding to
	171	* Timestamp Value zero is not specified". We use
	172	* zero to indicate absence of a meaningful timestamp.
	173	*/
76fd1e87	174	opt_val = get_unaligned((__be32 *)value);
b4d4f7c7 GR	175	if (unlikely(opt_val == 0)) {
	176	DCCP_WARN("Timestamp with zero value\n");
	177	break;
	178	}
7c657876	179
b4d4f7c7 GR	180	if (dreq != NULL) {
	181	dreq->dreq_timestamp_echo = ntohl(opt_val);
	182	dreq->dreq_timestamp_time = dccp_timestamp();
	183	} else {
	184	opt_recv->dccpor_timestamp =
	185	dp->dccps_timestamp_echo = ntohl(opt_val);
	186	dp->dccps_timestamp_time = dccp_timestamp();
	187	}
09dbc389	188	dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n",
b4d4f7c7	189	dccp_role(sk), ntohl(opt_val),
f6ccf554	190	(unsigned long long)
7c657876 ACM	191	DCCP_SKB_CB(skb)->dccpd_ack_seq);
	192	break;
	193	case DCCPO_TIMESTAMP_ECHO:
1bc09869	194	if (len != 4 && len != 6 && len != 8)
7c657876 ACM	195	goto out_invalid_option;
7c657876 ACM	196
76fd1e87 GR	197	opt_val = get_unaligned((__be32 *)value);
76fd1e87 GR	198	opt_recv->dccpor_timestamp_echo = ntohl(opt_val);
7c657876	199
09dbc389	200	dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, "
f73f7097	201	"ackno=%llu", dccp_role(sk),
7690af3f	202	opt_recv->dccpor_timestamp_echo,
f6ccf554 DM	203	len + 2,
f6ccf554 DM	204	(unsigned long long)
1bc09869 IM	205	DCCP_SKB_CB(skb)->dccpd_ack_seq);
1bc09869 IM	206
76fd1e87	207	value += 4;
1bc09869	208
76fd1e87	209	if (len == 4) { /* no elapsed time included */
f73f7097	210	dccp_pr_debug_cat("\n");
1c14ac0a	211	break;
f73f7097	212	}
1c14ac0a	213
76fd1e87 GR	214	if (len == 6) { /* 2-byte elapsed time */
	215	__be16 opt_val2 = get_unaligned((__be16 *)value);
	216	elapsed_time = ntohs(opt_val2);
	217	} else { /* 4-byte elapsed time */
	218	opt_val = get_unaligned((__be32 *)value);
	219	elapsed_time = ntohl(opt_val);
	220	}
1c14ac0a	221
dcad856f	222	dccp_pr_debug_cat(", ELAPSED_TIME=%u\n", elapsed_time);
f73f7097	223
1c14ac0a ACM	224	/* Give precedence to the biggest ELAPSED_TIME */
	225	if (elapsed_time > opt_recv->dccpor_elapsed_time)
	226	opt_recv->dccpor_elapsed_time = elapsed_time;
7c657876 ACM	227	break;
7c657876 ACM	228	case DCCPO_ELAPSED_TIME:
c86ab2b6 GR	229	if (dccp_packet_without_ack(skb)) /* RFC 4340, 13.2 */
c86ab2b6 GR	230	break;
1bc09869	231
76fd1e87 GR	232	if (len == 2) {
	233	__be16 opt_val2 = get_unaligned((__be16 *)value);
	234	elapsed_time = ntohs(opt_val2);
c86ab2b6	235	} else if (len == 4) {
76fd1e87 GR	236	opt_val = get_unaligned((__be32 *)value);
76fd1e87 GR	237	elapsed_time = ntohl(opt_val);
c86ab2b6 GR	238	} else {
c86ab2b6 GR	239	goto out_invalid_option;
76fd1e87	240	}
1c14ac0a ACM	241
	242	if (elapsed_time > opt_recv->dccpor_elapsed_time)
	243	opt_recv->dccpor_elapsed_time = elapsed_time;
1bc09869	244
09dbc389 GR	245	dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n",
09dbc389 GR	246	dccp_role(sk), elapsed_time);
7c657876	247	break;
7c657876 ACM	248	case 128 ... 191: {
	249	const u16 idx = value - options;
	250
7690af3f ACM	251	if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
	252	opt, len, idx,
	253	value) != 0)
7c657876 ACM	254	goto out_invalid_option;
	255	}
	256	break;
	257	case 192 ... 255: {
	258	const u16 idx = value - options;
	259
7690af3f ACM	260	if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
	261	opt, len, idx,
	262	value) != 0)
7c657876 ACM	263	goto out_invalid_option;
	264	}
	265	break;
	266	default:
59348b19 GR	267	DCCP_CRIT("DCCP(%p): option %d(len=%d) not "
59348b19 GR	268	"implemented, ignoring", sk, opt, len);
7c657876	269	break;
c9eaf173	270	}
8b819412	271	ignore_option:
afe00251 AB	272	if (opt != DCCPO_MANDATORY)
afe00251 AB	273	mandatory = 0;
7c657876 ACM	274	}
7c657876 ACM	275
6df9424a ACM	276	/* mandatory was the last byte in option list -> reset connection */
	277	if (mandatory)
	278	goto out_invalid_option;
	279
7c657876 ACM	280	return 0;
	281
	282	out_invalid_option:
	283	DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
	284	DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_OPTION_ERROR;
59348b19	285	DCCP_WARN("DCCP(%p): invalid option %d, len=%d", sk, opt, len);
7c657876 ACM	286	return -1;
	287	}
	288
b61fafc4 ACM	289	EXPORT_SYMBOL_GPL(dccp_parse_options);
b61fafc4 ACM	290
7c657876 ACM	291	static void dccp_encode_value_var(const u32 value, unsigned char *to,
	292	const unsigned int len)
	293	{
	294	if (len > 3)
	295	*to++ = (value & 0xFF000000) >> 24;
	296	if (len > 2)
	297	*to++ = (value & 0xFF0000) >> 16;
	298	if (len > 1)
	299	*to++ = (value & 0xFF00) >> 8;
	300	if (len > 0)
	301	*to++ = (value & 0xFF);
	302	}
	303
	304	static inline int dccp_ndp_len(const int ndp)
	305	{
	306	return likely(ndp <= 0xFF) ? 1 : ndp <= 0xFFFF ? 2 : 3;
	307	}
	308
2d0817d1	309	int dccp_insert_option(struct sock sk, struct sk_buff skb,
7c657876 ACM	310	const unsigned char option,
	311	const void *value, const unsigned char len)
	312	{
	313	unsigned char *to;
	314
2d0817d1 ACM	315	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN)
2d0817d1 ACM	316	return -1;
7c657876 ACM	317
	318	DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
	319
	320	to = skb_push(skb, len + 2);
	321	*to++ = option;
	322	*to++ = len + 2;
	323
	324	memcpy(to, value, len);
2d0817d1	325	return 0;
7c657876 ACM	326	}
	327
	328	EXPORT_SYMBOL_GPL(dccp_insert_option);
	329
2d0817d1	330	static int dccp_insert_option_ndp(struct sock sk, struct sk_buff skb)
7c657876 ACM	331	{
	332	struct dccp_sock *dp = dccp_sk(sk);
	333	int ndp = dp->dccps_ndp_count;
	334
	335	if (dccp_non_data_packet(skb))
	336	++dp->dccps_ndp_count;
	337	else
	338	dp->dccps_ndp_count = 0;
	339
	340	if (ndp > 0) {
	341	unsigned char *ptr;
	342	const int ndp_len = dccp_ndp_len(ndp);
	343	const int len = ndp_len + 2;
	344
	345	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
2d0817d1	346	return -1;
7c657876 ACM	347
	348	DCCP_SKB_CB(skb)->dccpd_opt_len += len;
	349
	350	ptr = skb_push(skb, len);
	351	*ptr++ = DCCPO_NDP_COUNT;
	352	*ptr++ = len;
	353	dccp_encode_value_var(ndp, ptr, ndp_len);
	354	}
2d0817d1 ACM	355
2d0817d1 ACM	356	return 0;
7c657876 ACM	357	}
	358
	359	static inline int dccp_elapsed_time_len(const u32 elapsed_time)
	360	{
b1c9fe7b	361	return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
7c657876 ACM	362	}
7c657876 ACM	363
2d0817d1 ACM	364	int dccp_insert_option_elapsed_time(struct sock sk, struct sk_buff skb,
2d0817d1 ACM	365	u32 elapsed_time)
7c657876	366	{
7c657876 ACM	367	const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
	368	const int len = 2 + elapsed_time_len;
	369	unsigned char *to;
	370
1bc09869	371	if (elapsed_time_len == 0)
2d0817d1	372	return 0;
7c657876	373
2d0817d1 ACM	374	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
2d0817d1 ACM	375	return -1;
7c657876 ACM	376
	377	DCCP_SKB_CB(skb)->dccpd_opt_len += len;
	378
	379	to = skb_push(skb, len);
	380	*to++ = DCCPO_ELAPSED_TIME;
	381	*to++ = len;
	382
1bc09869	383	if (elapsed_time_len == 2) {
60fe62e7	384	const __be16 var16 = htons((u16)elapsed_time);
1bc09869 IM	385	memcpy(to, &var16, 2);
1bc09869 IM	386	} else {
60fe62e7	387	const __be32 var32 = htonl(elapsed_time);
1bc09869 IM	388	memcpy(to, &var32, 4);
1bc09869 IM	389	}
7c657876	390
2d0817d1	391	return 0;
7c657876 ACM	392	}
7c657876 ACM	393
d4b81ff7	394	EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
7c657876	395
2d0817d1	396	int dccp_insert_option_timestamp(struct sock sk, struct sk_buff skb)
7c657876	397	{
4c70f383	398	__be32 now = htonl(dccp_timestamp());
1bc09869 IM	399	/* yes this will overflow but that is the point as we want a
	400	* 10 usec 32 bit timer which mean it wraps every 11.9 hours */
	401
2d0817d1	402	return dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
7c657876 ACM	403	}
7c657876 ACM	404
d4b81ff7 ACM	405	EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp);
d4b81ff7 ACM	406
b4d4f7c7 GR	407	static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp,
b4d4f7c7 GR	408	struct dccp_request_sock *dreq,
2d0817d1	409	struct sk_buff *skb)
7c657876	410	{
60fe62e7	411	__be32 tstamp_echo;
7c657876	412	unsigned char *to;
b4d4f7c7 GR	413	u32 elapsed_time, elapsed_time_len, len;
	414
	415	if (dreq != NULL) {
	416	elapsed_time = dccp_timestamp() - dreq->dreq_timestamp_time;
	417	tstamp_echo = htonl(dreq->dreq_timestamp_echo);
	418	dreq->dreq_timestamp_echo = 0;
	419	} else {
	420	elapsed_time = dccp_timestamp() - dp->dccps_timestamp_time;
	421	tstamp_echo = htonl(dp->dccps_timestamp_echo);
	422	dp->dccps_timestamp_echo = 0;
	423	}
	424
b0e56780 ACM	425	elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
	426	len = 6 + elapsed_time_len;
	427
2d0817d1 ACM	428	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
2d0817d1 ACM	429	return -1;
7c657876 ACM	430
	431	DCCP_SKB_CB(skb)->dccpd_opt_len += len;
	432
	433	to = skb_push(skb, len);
	434	*to++ = DCCPO_TIMESTAMP_ECHO;
	435	*to++ = len;
	436
7c657876 ACM	437	memcpy(to, &tstamp_echo, 4);
7c657876 ACM	438	to += 4;
afe00251	439
1bc09869	440	if (elapsed_time_len == 2) {
60fe62e7	441	const __be16 var16 = htons((u16)elapsed_time);
1bc09869 IM	442	memcpy(to, &var16, 2);
1bc09869 IM	443	} else if (elapsed_time_len == 4) {
60fe62e7	444	const __be32 var32 = htonl(elapsed_time);
1bc09869 IM	445	memcpy(to, &var32, 4);
1bc09869 IM	446	}
7c657876	447
2d0817d1	448	return 0;
7c657876 ACM	449	}
7c657876 ACM	450
afe00251	451	static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat,
c9eaf173	452	u8 *val, u8 len)
afe00251 AB	453	{
	454	u8 *to;
	455
	456	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 3 > DCCP_MAX_OPT_LEN) {
59348b19	457	DCCP_WARN("packet too small for feature %d option!\n", feat);
afe00251 AB	458	return -1;
	459	}
	460
	461	DCCP_SKB_CB(skb)->dccpd_opt_len += len + 3;
	462
	463	to = skb_push(skb, len + 3);
	464	*to++ = type;
	465	*to++ = len + 3;
	466	*to++ = feat;
	467
	468	if (len)
	469	memcpy(to, val, len);
afe00251	470
c02fdc0e GR	471	dccp_pr_debug("%s(%s (%d), ...), length %d\n",
	472	dccp_feat_typename(type),
	473	dccp_feat_name(feat), feat, len);
afe00251 AB	474	return 0;
	475	}
	476
2d0817d1	477	static int dccp_insert_options_feat(struct sock sk, struct sk_buff skb)
afe00251 AB	478	{
afe00251 AB	479	struct dccp_sock *dp = dccp_sk(sk);
a4bf3902	480	struct dccp_minisock *dmsk = dccp_msk(sk);
afe00251 AB	481	struct dccp_opt_pend opt, next;
	482	int change = 0;
	483
	484	/* confirm any options [NN opts] */
a4bf3902	485	list_for_each_entry_safe(opt, next, &dmsk->dccpms_conf, dccpop_node) {
afe00251 AB	486	dccp_insert_feat_opt(skb, opt->dccpop_type,
	487	opt->dccpop_feat, opt->dccpop_val,
	488	opt->dccpop_len);
	489	/* fear empty confirms */
	490	if (opt->dccpop_val)
	491	kfree(opt->dccpop_val);
	492	kfree(opt);
	493	}
a4bf3902	494	INIT_LIST_HEAD(&dmsk->dccpms_conf);
afe00251 AB	495
afe00251 AB	496	/* see which features we need to send */
a4bf3902	497	list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
afe00251 AB	498	/* see if we need to send any confirm */
	499	if (opt->dccpop_sc) {
	500	dccp_insert_feat_opt(skb, opt->dccpop_type + 1,
	501	opt->dccpop_feat,
	502	opt->dccpop_sc->dccpoc_val,
	503	opt->dccpop_sc->dccpoc_len);
	504
	505	BUG_ON(!opt->dccpop_sc->dccpoc_val);
	506	kfree(opt->dccpop_sc->dccpoc_val);
	507	kfree(opt->dccpop_sc);
	508	opt->dccpop_sc = NULL;
	509	}
	510
	511	/* any option not confirmed, re-send it */
	512	if (!opt->dccpop_conf) {
	513	dccp_insert_feat_opt(skb, opt->dccpop_type,
	514	opt->dccpop_feat, opt->dccpop_val,
	515	opt->dccpop_len);
	516	change++;
	517	}
	518	}
	519
	520	/* Retransmit timer.
	521	* If this is the master listening sock, we don't set a timer on it. It
	522	* should be fine because if the dude doesn't receive our RESPONSE
	523	* [which will contain the CHANGE] he will send another REQUEST which
	524	* will "retrnasmit" the change.
	525	*/
	526	if (change && dp->dccps_role != DCCP_ROLE_LISTEN) {
	527	dccp_pr_debug("reset feat negotiation timer %p\n", sk);
	528
	529	/* XXX don't reset the timer on re-transmissions. I.e. reset it
	530	* only when sending new stuff i guess. Currently the timer
	531	* never backs off because on re-transmission it just resets it!
	532	*/
	533	inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
	534	inet_csk(sk)->icsk_rto, DCCP_RTO_MAX);
	535	}
2d0817d1 ACM	536
2d0817d1 ACM	537	return 0;
afe00251 AB	538	}
afe00251 AB	539
2d0817d1	540	int dccp_insert_options(struct sock sk, struct sk_buff skb)
7c657876 ACM	541	{
7c657876 ACM	542	struct dccp_sock *dp = dccp_sk(sk);
a4bf3902	543	struct dccp_minisock *dmsk = dccp_msk(sk);
7c657876 ACM	544
	545	DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
	546
a4bf3902	547	if (dmsk->dccpms_send_ndp_count &&
2d0817d1 ACM	548	dccp_insert_option_ndp(sk, skb))
2d0817d1 ACM	549	return -1;
7c657876 ACM	550
7c657876 ACM	551	if (!dccp_packet_without_ack(skb)) {
a4bf3902	552	if (dmsk->dccpms_send_ack_vector &&
2d0817d1 ACM	553	dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) &&
	554	dccp_insert_option_ackvec(sk, skb))
	555	return -1;
7c657876 ACM	556	}
7c657876 ACM	557
507d37cf	558	if (dp->dccps_hc_rx_insert_options) {
2d0817d1 ACM	559	if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb))
2d0817d1 ACM	560	return -1;
507d37cf ACM	561	dp->dccps_hc_rx_insert_options = 0;
507d37cf ACM	562	}
7c657876	563
afe00251	564	/* Feature negotiation */
2d0817d1 ACM	565	/* Data packets can't do feat negotiation */
	566	if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA &&
	567	DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATAACK &&
	568	dccp_insert_options_feat(sk, skb))
	569	return -1;
afe00251	570
89560b53 GR	571	/*
	572	* Obtain RTT sample from Request/Response exchange.
	573	* This is currently used in CCID 3 initialisation.
	574	*/
	575	if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST &&
	576	dccp_insert_option_timestamp(sk, skb))
	577	return -1;
	578
b4d4f7c7 GR	579	if (dp->dccps_timestamp_echo != 0 &&
	580	dccp_insert_option_timestamp_echo(dp, NULL, skb))
	581	return -1;
	582
7c657876 ACM	583	/* XXX: insert other options when appropriate */
	584
	585	if (DCCP_SKB_CB(skb)->dccpd_opt_len != 0) {
	586	/* The length of all options has to be a multiple of 4 */
	587	int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4;
	588
	589	if (padding != 0) {
	590	padding = 4 - padding;
	591	memset(skb_push(skb, padding), 0, padding);
	592	DCCP_SKB_CB(skb)->dccpd_opt_len += padding;
	593	}
	594	}
2d0817d1 ACM	595
2d0817d1 ACM	596	return 0;
7c657876	597	}