[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 <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;

EXPORT_SYMBOL_GPL(sysctl_dccp_feat_sequence_window);

void dccp_minisock_init(struct dccp_minisock *dmsk)
{
	dmsk->dccpms_sequence_window = sysctl_dccp_feat_sequence_window;
	dmsk->dccpms_rx_ccid	     = sysctl_dccp_feat_rx_ccid;
	dmsk->dccpms_tx_ccid	     = sysctl_dccp_feat_tx_ccid;
	dmsk->dccpms_ack_ratio	     = sysctl_dccp_feat_ack_ratio;
	dmsk->dccpms_send_ack_vector = sysctl_dccp_feat_send_ack_vector;
	dmsk->dccpms_send_ndp_count  = sysctl_dccp_feat_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;
}

int dccp_parse_options(struct sock *sk, 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;
	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;
		}

		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 (pkt_type == DCCP_PKT_DATA)
				break;

			if (dccp_msk(sk)->dccpms_send_ack_vector &&
			    dccp_ackvec_parse(sk, skb, opt, value, len))
				goto out_invalid_option;
			break;
		case DCCPO_TIMESTAMP:
			if (len != 4)
				goto out_invalid_option;

			opt_recv->dccpor_timestamp = ntohl(*(__be32 *)value);

			dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp;
			dccp_timestamp(sk, &dp->dccps_timestamp_time);

			dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n",
				      dccp_role(sk), opt_recv->dccpor_timestamp,
				      (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_recv->dccpor_timestamp_echo = ntohl(*(__be32 *)value);

			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);


			if (len == 4)
				break;

			if (len == 6)
				elapsed_time = ntohs(*(__be16 *)(value + 4));
			else
				elapsed_time = ntohl(*(__be32 *)(value + 4));

			/* 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 (len != 2 && len != 4)
				goto out_invalid_option;

			if (pkt_type == DCCP_PKT_DATA)
				continue;

			if (len == 2)
				elapsed_time = ntohs(*(__be16 *)value);
			else
				elapsed_time = ntohl(*(__be32 *)value);

			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;
			/*
			 * 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.
			 */
		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:
			pr_info("DCCP(%p): option %d(len=%d) not "
				"implemented, ignoring\n",
				sk, opt, len);
			break;
	        }

		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;
	pr_info("DCCP(%p): invalid option %d, len=%d\n", 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);

void dccp_timestamp(const struct sock *sk, struct timeval *tv)
{
	const struct dccp_sock *dp = dccp_sk(sk);

	do_gettimeofday(tv);
	tv->tv_sec  -= dp->dccps_epoch.tv_sec;
	tv->tv_usec -= dp->dccps_epoch.tv_usec;

	while (tv->tv_usec < 0) {
		tv->tv_sec--;
		tv->tv_usec += USEC_PER_SEC;
	}
}

EXPORT_SYMBOL_GPL(dccp_timestamp);

int dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb)
{
	struct timeval tv;
	__be32 now;

	dccp_timestamp(sk, &tv);
	now = htonl(timeval_usecs(&tv) / 10);
	/* 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 sock *sk,
					     struct sk_buff *skb)
{
	struct dccp_sock *dp = dccp_sk(sk);
	struct timeval now;
	__be32 tstamp_echo;
	u32 elapsed_time;
	int len, elapsed_time_len;
	unsigned char *to;

	dccp_timestamp(sk, &now);
	elapsed_time = timeval_delta(&now, &dp->dccps_timestamp_time) / 10;
	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;

	tstamp_echo = htonl(dp->dccps_timestamp_echo);
	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);
	}

	dp->dccps_timestamp_echo = 0;
	dp->dccps_timestamp_time.tv_sec = 0;
	dp->dccps_timestamp_time.tv_usec = 0;
	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) {
		LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small"
			       " to insert 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_timestamp_echo != 0 &&
		    dccp_insert_option_timestamp_echo(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_hc_tx_insert_options) {
		if (ccid_hc_tx_insert_options(dp->dccps_hc_tx_ccid, sk, skb))
			return -1;
		dp->dccps_hc_tx_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;

	/* 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>
	17	#include <linux/kernel.h>
	18	#include <linux/skbuff.h>
	19
ae31c339	20	#include "ackvec.h"
7c657876 ACM	21	#include "ccid.h"
7c657876 ACM	22	#include "dccp.h"
afe00251	23	#include "feat.h"
7c657876	24
afb0a34d GR	25	int sysctl_dccp_feat_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW;
	26	int sysctl_dccp_feat_rx_ccid = DCCPF_INITIAL_CCID;
	27	int sysctl_dccp_feat_tx_ccid = DCCPF_INITIAL_CCID;
	28	int sysctl_dccp_feat_ack_ratio = DCCPF_INITIAL_ACK_RATIO;
	29	int sysctl_dccp_feat_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR;
	30	int sysctl_dccp_feat_send_ndp_count = DCCPF_INITIAL_SEND_NDP_COUNT;
7c657876	31
afb0a34d	32	EXPORT_SYMBOL_GPL(sysctl_dccp_feat_sequence_window);
4b79f0af	33
a4bf3902	34	void dccp_minisock_init(struct dccp_minisock *dmsk)
7c657876	35	{
afb0a34d GR	36	dmsk->dccpms_sequence_window = sysctl_dccp_feat_sequence_window;
	37	dmsk->dccpms_rx_ccid = sysctl_dccp_feat_rx_ccid;
	38	dmsk->dccpms_tx_ccid = sysctl_dccp_feat_tx_ccid;
	39	dmsk->dccpms_ack_ratio = sysctl_dccp_feat_ack_ratio;
	40	dmsk->dccpms_send_ack_vector = sysctl_dccp_feat_send_ack_vector;
	41	dmsk->dccpms_send_ndp_count = sysctl_dccp_feat_send_ndp_count;
7c657876 ACM	42	}
	43
	44	static u32 dccp_decode_value_var(const unsigned char *bf, const u8 len)
	45	{
	46	u32 value = 0;
	47
	48	if (len > 3)
	49	value += *bf++ << 24;
	50	if (len > 2)
	51	value += *bf++ << 16;
	52	if (len > 1)
	53	value += *bf++ << 8;
	54	if (len > 0)
	55	value += *bf;
	56
	57	return value;
	58	}
	59
	60	int dccp_parse_options(struct sock sk, struct sk_buff skb)
	61	{
	62	struct dccp_sock *dp = dccp_sk(sk);
7c657876 ACM	63	const struct dccp_hdr *dh = dccp_hdr(skb);
	64	const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type;
	65	unsigned char options = (unsigned char )dh + dccp_hdr_len(skb);
	66	unsigned char *opt_ptr = options;
7690af3f ACM	67	const unsigned char opt_end = (unsigned char )dh +
7690af3f ACM	68	(dh->dccph_doff * 4);
7c657876 ACM	69	struct dccp_options_received *opt_recv = &dp->dccps_options_received;
	70	unsigned char opt, len;
	71	unsigned char *value;
1c14ac0a	72	u32 elapsed_time;
afe00251 AB	73	int rc;
afe00251 AB	74	int mandatory = 0;
7c657876 ACM	75
	76	memset(opt_recv, 0, sizeof(*opt_recv));
	77
fb950496	78	opt = len = 0;
7c657876 ACM	79	while (opt_ptr != opt_end) {
	80	opt = *opt_ptr++;
	81	len = 0;
	82	value = NULL;
	83
	84	/* Check if this isn't a single byte option */
	85	if (opt > DCCPO_MAX_RESERVED) {
	86	if (opt_ptr == opt_end)
	87	goto out_invalid_option;
	88
	89	len = *opt_ptr++;
	90	if (len < 3)
	91	goto out_invalid_option;
	92	/*
	93	* Remove the type and len fields, leaving
	94	* just the value size
	95	*/
	96	len -= 2;
	97	value = opt_ptr;
	98	opt_ptr += len;
	99
	100	if (opt_ptr > opt_end)
	101	goto out_invalid_option;
	102	}
	103
	104	switch (opt) {
	105	case DCCPO_PADDING:
	106	break;
afe00251 AB	107	case DCCPO_MANDATORY:
	108	if (mandatory)
	109	goto out_invalid_option;
6df9424a ACM	110	if (pkt_type != DCCP_PKT_DATA)
6df9424a ACM	111	mandatory = 1;
afe00251	112	break;
7c657876 ACM	113	case DCCPO_NDP_COUNT:
	114	if (len > 3)
	115	goto out_invalid_option;
	116
	117	opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
09dbc389	118	dccp_pr_debug("%s rx opt: NDP count=%d\n", dccp_role(sk),
7690af3f	119	opt_recv->dccpor_ndp);
7c657876	120	break;
afe00251 AB	121	case DCCPO_CHANGE_L:
	122	/* fall through */
	123	case DCCPO_CHANGE_R:
	124	if (len < 2)
	125	goto out_invalid_option;
	126	rc = dccp_feat_change_recv(sk, opt, *value, value + 1,
	127	len - 1);
	128	/*
	129	* When there is a change error, change_recv is
	130	* responsible for dealing with it. i.e. reply with an
	131	* empty confirm.
	132	* If the change was mandatory, then we need to die.
	133	*/
	134	if (rc && mandatory)
	135	goto out_invalid_option;
	136	break;
	137	case DCCPO_CONFIRM_L:
	138	/* fall through */
	139	case DCCPO_CONFIRM_R:
	140	if (len < 2)
	141	goto out_invalid_option;
	142	if (dccp_feat_confirm_recv(sk, opt, *value,
	143	value + 1, len - 1))
	144	goto out_invalid_option;
	145	break;
7c657876	146	case DCCPO_ACK_VECTOR_0:
ae31c339	147	case DCCPO_ACK_VECTOR_1:
7c657876	148	if (pkt_type == DCCP_PKT_DATA)
e5a6de91	149	break;
7c657876	150
a4bf3902	151	if (dccp_msk(sk)->dccpms_send_ack_vector &&
ae31c339 ACM	152	dccp_ackvec_parse(sk, skb, opt, value, len))
ae31c339 ACM	153	goto out_invalid_option;
7c657876 ACM	154	break;
	155	case DCCPO_TIMESTAMP:
	156	if (len != 4)
	157	goto out_invalid_option;
	158
60fe62e7	159	opt_recv->dccpor_timestamp = ntohl((__be32 )value);
7c657876 ACM	160
7c657876 ACM	161	dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp;
b0e56780	162	dccp_timestamp(sk, &dp->dccps_timestamp_time);
7c657876	163
09dbc389 GR	164	dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n",
09dbc389 GR	165	dccp_role(sk), opt_recv->dccpor_timestamp,
f6ccf554	166	(unsigned long long)
7c657876 ACM	167	DCCP_SKB_CB(skb)->dccpd_ack_seq);
	168	break;
	169	case DCCPO_TIMESTAMP_ECHO:
1bc09869	170	if (len != 4 && len != 6 && len != 8)
7c657876 ACM	171	goto out_invalid_option;
7c657876 ACM	172
60fe62e7	173	opt_recv->dccpor_timestamp_echo = ntohl((__be32 )value);
7c657876	174
09dbc389 GR	175	dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, "
09dbc389 GR	176	"ackno=%llu, ", dccp_role(sk),
7690af3f	177	opt_recv->dccpor_timestamp_echo,
f6ccf554 DM	178	len + 2,
f6ccf554 DM	179	(unsigned long long)
1bc09869 IM	180	DCCP_SKB_CB(skb)->dccpd_ack_seq);
1bc09869 IM	181
1bc09869	182
1c14ac0a ACM	183	if (len == 4)
	184	break;
	185
	186	if (len == 6)
60fe62e7	187	elapsed_time = ntohs((__be16 )(value + 4));
1c14ac0a	188	else
60fe62e7	189	elapsed_time = ntohl((__be32 )(value + 4));
1c14ac0a ACM	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;
7c657876 ACM	194	break;
7c657876 ACM	195	case DCCPO_ELAPSED_TIME:
1bc09869	196	if (len != 2 && len != 4)
7c657876 ACM	197	goto out_invalid_option;
	198
	199	if (pkt_type == DCCP_PKT_DATA)
	200	continue;
1bc09869 IM	201
1bc09869 IM	202	if (len == 2)
60fe62e7	203	elapsed_time = ntohs((__be16 )value);
1bc09869	204	else
60fe62e7	205	elapsed_time = ntohl((__be32 )value);
1c14ac0a ACM	206
	207	if (elapsed_time > opt_recv->dccpor_elapsed_time)
	208	opt_recv->dccpor_elapsed_time = elapsed_time;
1bc09869	209
09dbc389 GR	210	dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n",
09dbc389 GR	211	dccp_role(sk), elapsed_time);
7c657876 ACM	212	break;
7c657876 ACM	213	/*
0e64e94e	214	* From RFC 4340, sec. 10.3:
7c657876	215	*
7690af3f ACM	216	* Option numbers 128 through 191 are for
	217	* options sent from the HC-Sender to the
	218	* HC-Receiver; option numbers 192 through 255
	219	* are for options sent from the HC-Receiver to
	220	* the HC-Sender.
7c657876 ACM	221	*/
	222	case 128 ... 191: {
	223	const u16 idx = value - options;
	224
7690af3f ACM	225	if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
	226	opt, len, idx,
	227	value) != 0)
7c657876 ACM	228	goto out_invalid_option;
	229	}
	230	break;
	231	case 192 ... 255: {
	232	const u16 idx = value - options;
	233
7690af3f ACM	234	if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
	235	opt, len, idx,
	236	value) != 0)
7c657876 ACM	237	goto out_invalid_option;
	238	}
	239	break;
	240	default:
7690af3f ACM	241	pr_info("DCCP(%p): option %d(len=%d) not "
7690af3f ACM	242	"implemented, ignoring\n",
7c657876 ACM	243	sk, opt, len);
	244	break;
	245	}
afe00251 AB	246
	247	if (opt != DCCPO_MANDATORY)
	248	mandatory = 0;
7c657876 ACM	249	}
7c657876 ACM	250
6df9424a ACM	251	/* mandatory was the last byte in option list -> reset connection */
	252	if (mandatory)
	253	goto out_invalid_option;
	254
7c657876 ACM	255	return 0;
	256
	257	out_invalid_option:
	258	DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
	259	DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_OPTION_ERROR;
	260	pr_info("DCCP(%p): invalid option %d, len=%d\n", sk, opt, len);
	261	return -1;
	262	}
	263
b61fafc4 ACM	264	EXPORT_SYMBOL_GPL(dccp_parse_options);
b61fafc4 ACM	265
7c657876 ACM	266	static void dccp_encode_value_var(const u32 value, unsigned char *to,
	267	const unsigned int len)
	268	{
	269	if (len > 3)
	270	*to++ = (value & 0xFF000000) >> 24;
	271	if (len > 2)
	272	*to++ = (value & 0xFF0000) >> 16;
	273	if (len > 1)
	274	*to++ = (value & 0xFF00) >> 8;
	275	if (len > 0)
	276	*to++ = (value & 0xFF);
	277	}
	278
	279	static inline int dccp_ndp_len(const int ndp)
	280	{
	281	return likely(ndp <= 0xFF) ? 1 : ndp <= 0xFFFF ? 2 : 3;
	282	}
	283
2d0817d1	284	int dccp_insert_option(struct sock sk, struct sk_buff skb,
7c657876 ACM	285	const unsigned char option,
	286	const void *value, const unsigned char len)
	287	{
	288	unsigned char *to;
	289
2d0817d1 ACM	290	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN)
2d0817d1 ACM	291	return -1;
7c657876 ACM	292
	293	DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
	294
	295	to = skb_push(skb, len + 2);
	296	*to++ = option;
	297	*to++ = len + 2;
	298
	299	memcpy(to, value, len);
2d0817d1	300	return 0;
7c657876 ACM	301	}
	302
	303	EXPORT_SYMBOL_GPL(dccp_insert_option);
	304
2d0817d1	305	static int dccp_insert_option_ndp(struct sock sk, struct sk_buff skb)
7c657876 ACM	306	{
	307	struct dccp_sock *dp = dccp_sk(sk);
	308	int ndp = dp->dccps_ndp_count;
	309
	310	if (dccp_non_data_packet(skb))
	311	++dp->dccps_ndp_count;
	312	else
	313	dp->dccps_ndp_count = 0;
	314
	315	if (ndp > 0) {
	316	unsigned char *ptr;
	317	const int ndp_len = dccp_ndp_len(ndp);
	318	const int len = ndp_len + 2;
	319
	320	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
2d0817d1	321	return -1;
7c657876 ACM	322
	323	DCCP_SKB_CB(skb)->dccpd_opt_len += len;
	324
	325	ptr = skb_push(skb, len);
	326	*ptr++ = DCCPO_NDP_COUNT;
	327	*ptr++ = len;
	328	dccp_encode_value_var(ndp, ptr, ndp_len);
	329	}
2d0817d1 ACM	330
2d0817d1 ACM	331	return 0;
7c657876 ACM	332	}
	333
	334	static inline int dccp_elapsed_time_len(const u32 elapsed_time)
	335	{
b1c9fe7b	336	return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
7c657876 ACM	337	}
7c657876 ACM	338
2d0817d1 ACM	339	int dccp_insert_option_elapsed_time(struct sock sk, struct sk_buff skb,
2d0817d1 ACM	340	u32 elapsed_time)
7c657876	341	{
7c657876 ACM	342	const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
	343	const int len = 2 + elapsed_time_len;
	344	unsigned char *to;
	345
1bc09869	346	if (elapsed_time_len == 0)
2d0817d1	347	return 0;
7c657876	348
2d0817d1 ACM	349	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
2d0817d1 ACM	350	return -1;
7c657876 ACM	351
	352	DCCP_SKB_CB(skb)->dccpd_opt_len += len;
	353
	354	to = skb_push(skb, len);
	355	*to++ = DCCPO_ELAPSED_TIME;
	356	*to++ = len;
	357
1bc09869	358	if (elapsed_time_len == 2) {
60fe62e7	359	const __be16 var16 = htons((u16)elapsed_time);
1bc09869 IM	360	memcpy(to, &var16, 2);
1bc09869 IM	361	} else {
60fe62e7	362	const __be32 var32 = htonl(elapsed_time);
1bc09869 IM	363	memcpy(to, &var32, 4);
1bc09869 IM	364	}
7c657876	365
2d0817d1	366	return 0;
7c657876 ACM	367	}
7c657876 ACM	368
d4b81ff7	369	EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
7c657876	370
b0e56780 ACM	371	void dccp_timestamp(const struct sock sk, struct timeval tv)
	372	{
	373	const struct dccp_sock *dp = dccp_sk(sk);
	374
	375	do_gettimeofday(tv);
	376	tv->tv_sec -= dp->dccps_epoch.tv_sec;
	377	tv->tv_usec -= dp->dccps_epoch.tv_usec;
	378
	379	while (tv->tv_usec < 0) {
	380	tv->tv_sec--;
	381	tv->tv_usec += USEC_PER_SEC;
	382	}
	383	}
	384
	385	EXPORT_SYMBOL_GPL(dccp_timestamp);
	386
2d0817d1	387	int dccp_insert_option_timestamp(struct sock sk, struct sk_buff skb)
7c657876	388	{
1bc09869	389	struct timeval tv;
60fe62e7	390	__be32 now;
afe00251	391
b0e56780	392	dccp_timestamp(sk, &tv);
60fe62e7	393	now = htonl(timeval_usecs(&tv) / 10);
1bc09869 IM	394	/* yes this will overflow but that is the point as we want a
	395	* 10 usec 32 bit timer which mean it wraps every 11.9 hours */
	396
2d0817d1	397	return dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
7c657876 ACM	398	}
7c657876 ACM	399
d4b81ff7 ACM	400	EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp);
d4b81ff7 ACM	401
2d0817d1 ACM	402	static int dccp_insert_option_timestamp_echo(struct sock *sk,
2d0817d1 ACM	403	struct sk_buff *skb)
7c657876 ACM	404	{
7c657876 ACM	405	struct dccp_sock *dp = dccp_sk(sk);
b0e56780	406	struct timeval now;
60fe62e7	407	__be32 tstamp_echo;
b0e56780 ACM	408	u32 elapsed_time;
b0e56780 ACM	409	int len, elapsed_time_len;
7c657876 ACM	410	unsigned char *to;
7c657876 ACM	411
b0e56780 ACM	412	dccp_timestamp(sk, &now);
	413	elapsed_time = timeval_delta(&now, &dp->dccps_timestamp_time) / 10;
	414	elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
	415	len = 6 + elapsed_time_len;
	416
2d0817d1 ACM	417	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
2d0817d1 ACM	418	return -1;
7c657876 ACM	419
	420	DCCP_SKB_CB(skb)->dccpd_opt_len += len;
	421
	422	to = skb_push(skb, len);
	423	*to++ = DCCPO_TIMESTAMP_ECHO;
	424	*to++ = len;
	425
	426	tstamp_echo = htonl(dp->dccps_timestamp_echo);
	427	memcpy(to, &tstamp_echo, 4);
	428	to += 4;
afe00251	429
1bc09869	430	if (elapsed_time_len == 2) {
60fe62e7	431	const __be16 var16 = htons((u16)elapsed_time);
1bc09869 IM	432	memcpy(to, &var16, 2);
1bc09869 IM	433	} else if (elapsed_time_len == 4) {
60fe62e7	434	const __be32 var32 = htonl(elapsed_time);
1bc09869 IM	435	memcpy(to, &var32, 4);
1bc09869 IM	436	}
7c657876	437
7c657876	438	dp->dccps_timestamp_echo = 0;
1bc09869 IM	439	dp->dccps_timestamp_time.tv_sec = 0;
1bc09869 IM	440	dp->dccps_timestamp_time.tv_usec = 0;
2d0817d1	441	return 0;
7c657876 ACM	442	}
7c657876 ACM	443
afe00251 AB	444	static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat,
	445	u8 *val, u8 len)
	446	{
	447	u8 *to;
	448
	449	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 3 > DCCP_MAX_OPT_LEN) {
	450	LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small"
	451	" to insert feature %d option!\n", feat);
	452	return -1;
	453	}
	454
	455	DCCP_SKB_CB(skb)->dccpd_opt_len += len + 3;
	456
	457	to = skb_push(skb, len + 3);
	458	*to++ = type;
	459	*to++ = len + 3;
	460	*to++ = feat;
	461
	462	if (len)
	463	memcpy(to, val, len);
afe00251	464
c02fdc0e GR	465	dccp_pr_debug("%s(%s (%d), ...), length %d\n",
	466	dccp_feat_typename(type),
	467	dccp_feat_name(feat), feat, len);
afe00251 AB	468	return 0;
	469	}
	470
2d0817d1	471	static int dccp_insert_options_feat(struct sock sk, struct sk_buff skb)
afe00251 AB	472	{
afe00251 AB	473	struct dccp_sock *dp = dccp_sk(sk);
a4bf3902	474	struct dccp_minisock *dmsk = dccp_msk(sk);
afe00251 AB	475	struct dccp_opt_pend opt, next;
	476	int change = 0;
	477
	478	/* confirm any options [NN opts] */
a4bf3902	479	list_for_each_entry_safe(opt, next, &dmsk->dccpms_conf, dccpop_node) {
afe00251 AB	480	dccp_insert_feat_opt(skb, opt->dccpop_type,
	481	opt->dccpop_feat, opt->dccpop_val,
	482	opt->dccpop_len);
	483	/* fear empty confirms */
	484	if (opt->dccpop_val)
	485	kfree(opt->dccpop_val);
	486	kfree(opt);
	487	}
a4bf3902	488	INIT_LIST_HEAD(&dmsk->dccpms_conf);
afe00251 AB	489
afe00251 AB	490	/* see which features we need to send */
a4bf3902	491	list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
afe00251 AB	492	/* see if we need to send any confirm */
	493	if (opt->dccpop_sc) {
	494	dccp_insert_feat_opt(skb, opt->dccpop_type + 1,
	495	opt->dccpop_feat,
	496	opt->dccpop_sc->dccpoc_val,
	497	opt->dccpop_sc->dccpoc_len);
	498
	499	BUG_ON(!opt->dccpop_sc->dccpoc_val);
	500	kfree(opt->dccpop_sc->dccpoc_val);
	501	kfree(opt->dccpop_sc);
	502	opt->dccpop_sc = NULL;
	503	}
	504
	505	/* any option not confirmed, re-send it */
	506	if (!opt->dccpop_conf) {
	507	dccp_insert_feat_opt(skb, opt->dccpop_type,
	508	opt->dccpop_feat, opt->dccpop_val,
	509	opt->dccpop_len);
	510	change++;
	511	}
	512	}
	513
	514	/* Retransmit timer.
	515	* If this is the master listening sock, we don't set a timer on it. It
	516	* should be fine because if the dude doesn't receive our RESPONSE
	517	* [which will contain the CHANGE] he will send another REQUEST which
	518	* will "retrnasmit" the change.
	519	*/
	520	if (change && dp->dccps_role != DCCP_ROLE_LISTEN) {
	521	dccp_pr_debug("reset feat negotiation timer %p\n", sk);
	522
	523	/* XXX don't reset the timer on re-transmissions. I.e. reset it
	524	* only when sending new stuff i guess. Currently the timer
	525	* never backs off because on re-transmission it just resets it!
	526	*/
	527	inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
	528	inet_csk(sk)->icsk_rto, DCCP_RTO_MAX);
	529	}
2d0817d1 ACM	530
2d0817d1 ACM	531	return 0;
afe00251 AB	532	}
afe00251 AB	533
2d0817d1	534	int dccp_insert_options(struct sock sk, struct sk_buff skb)
7c657876 ACM	535	{
7c657876 ACM	536	struct dccp_sock *dp = dccp_sk(sk);
a4bf3902	537	struct dccp_minisock *dmsk = dccp_msk(sk);
7c657876 ACM	538
	539	DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
	540
a4bf3902	541	if (dmsk->dccpms_send_ndp_count &&
2d0817d1 ACM	542	dccp_insert_option_ndp(sk, skb))
2d0817d1 ACM	543	return -1;
7c657876 ACM	544
7c657876 ACM	545	if (!dccp_packet_without_ack(skb)) {
a4bf3902	546	if (dmsk->dccpms_send_ack_vector &&
2d0817d1 ACM	547	dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) &&
	548	dccp_insert_option_ackvec(sk, skb))
	549	return -1;
	550
	551	if (dp->dccps_timestamp_echo != 0 &&
	552	dccp_insert_option_timestamp_echo(sk, skb))
	553	return -1;
7c657876 ACM	554	}
7c657876 ACM	555
507d37cf	556	if (dp->dccps_hc_rx_insert_options) {
2d0817d1 ACM	557	if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb))
2d0817d1 ACM	558	return -1;
507d37cf ACM	559	dp->dccps_hc_rx_insert_options = 0;
	560	}
	561	if (dp->dccps_hc_tx_insert_options) {
2d0817d1 ACM	562	if (ccid_hc_tx_insert_options(dp->dccps_hc_tx_ccid, sk, skb))
2d0817d1 ACM	563	return -1;
507d37cf ACM	564	dp->dccps_hc_tx_insert_options = 0;
507d37cf ACM	565	}
7c657876	566
afe00251	567	/* Feature negotiation */
2d0817d1 ACM	568	/* Data packets can't do feat negotiation */
	569	if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA &&
	570	DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATAACK &&
	571	dccp_insert_options_feat(sk, skb))
	572	return -1;
afe00251	573
7c657876 ACM	574	/* XXX: insert other options when appropriate */
	575
	576	if (DCCP_SKB_CB(skb)->dccpd_opt_len != 0) {
	577	/* The length of all options has to be a multiple of 4 */
	578	int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4;
	579
	580	if (padding != 0) {
	581	padding = 4 - padding;
	582	memset(skb_push(skb, padding), 0, padding);
	583	DCCP_SKB_CB(skb)->dccpd_opt_len += padding;
	584	}
	585	}
2d0817d1 ACM	586
2d0817d1 ACM	587	return 0;
7c657876	588	}