[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 <iam4@cs.waikato.ac.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/config.h>
#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 dccp_feat_default_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW;
int dccp_feat_default_rx_ccid	      = DCCPF_INITIAL_CCID;
int dccp_feat_default_tx_ccid	      = DCCPF_INITIAL_CCID;
int dccp_feat_default_ack_ratio	      = DCCPF_INITIAL_ACK_RATIO;
int dccp_feat_default_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR;
int dccp_feat_default_send_ndp_count  = DCCPF_INITIAL_SEND_NDP_COUNT;

void dccp_options_init(struct dccp_options *dccpo)
{
	dccpo->dccpo_sequence_window = dccp_feat_default_sequence_window;
	dccpo->dccpo_rx_ccid	     = dccp_feat_default_rx_ccid;
	dccpo->dccpo_tx_ccid	     = dccp_feat_default_tx_ccid;
	dccpo->dccpo_ack_ratio	     = dccp_feat_default_ack_ratio;
	dccpo->dccpo_send_ack_vector = dccp_feat_default_send_ack_vector;
	dccpo->dccpo_send_ndp_count  = dccp_feat_default_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);
#ifdef CONFIG_IP_DCCP_DEBUG
	const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
					"CLIENT rx opt: " : "server rx opt: ";
#endif
	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));

	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("%sNDP count=%d\n", debug_prefix,
				      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 (dp->dccps_options.dccpo_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("%sTIMESTAMP=%u, ackno=%llu\n",
				      debug_prefix, 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("%sTIMESTAMP_ECHO=%u, len=%d, ackno=%llu, ",
				      debug_prefix,
				      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("%sELAPSED_TIME=%d\n", debug_prefix,
				      elapsed_time);
			break;
			/*
			 * From draft-ietf-dccp-spec-11.txt:
			 *
			 *	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("option %d feat %d len %d\n", type, 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_opt_pend *opt, *next;
	int change = 0;

	/* confirm any options [NN opts] */
	list_for_each_entry_safe(opt, next, &dp->dccps_options.dccpo_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(&dp->dccps_options.dccpo_conf);

	/* see which features we need to send */
	list_for_each_entry(opt, &dp->dccps_options.dccpo_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);

	DCCP_SKB_CB(skb)->dccpd_opt_len = 0;

	if (dp->dccps_options.dccpo_send_ndp_count &&
	    dccp_insert_option_ndp(sk, skb))
		return -1;

	if (!dccp_packet_without_ack(skb)) {
		if (dp->dccps_options.dccpo_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>
	6	* Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
	7	* Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.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	*/
	14	#include <linux/config.h>
	15	#include <linux/dccp.h>
	16	#include <linux/module.h>
	17	#include <linux/types.h>
	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
e55d912f ACM	26	int dccp_feat_default_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW;
	27	int dccp_feat_default_rx_ccid = DCCPF_INITIAL_CCID;
	28	int dccp_feat_default_tx_ccid = DCCPF_INITIAL_CCID;
	29	int dccp_feat_default_ack_ratio = DCCPF_INITIAL_ACK_RATIO;
	30	int dccp_feat_default_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR;
	31	int dccp_feat_default_send_ndp_count = DCCPF_INITIAL_SEND_NDP_COUNT;
7c657876 ACM	32
	33	void dccp_options_init(struct dccp_options *dccpo)
	34	{
e55d912f ACM	35	dccpo->dccpo_sequence_window = dccp_feat_default_sequence_window;
	36	dccpo->dccpo_rx_ccid = dccp_feat_default_rx_ccid;
	37	dccpo->dccpo_tx_ccid = dccp_feat_default_tx_ccid;
	38	dccpo->dccpo_ack_ratio = dccp_feat_default_ack_ratio;
	39	dccpo->dccpo_send_ack_vector = dccp_feat_default_send_ack_vector;
	40	dccpo->dccpo_send_ndp_count = dccp_feat_default_send_ndp_count;
7c657876 ACM	41	}
	42
	43	static u32 dccp_decode_value_var(const unsigned char *bf, const u8 len)
	44	{
	45	u32 value = 0;
	46
	47	if (len > 3)
	48	value += *bf++ << 24;
	49	if (len > 2)
	50	value += *bf++ << 16;
	51	if (len > 1)
	52	value += *bf++ << 8;
	53	if (len > 0)
	54	value += *bf;
	55
	56	return value;
	57	}
	58
	59	int dccp_parse_options(struct sock sk, struct sk_buff skb)
	60	{
	61	struct dccp_sock *dp = dccp_sk(sk);
725ba8ee	62	#ifdef CONFIG_IP_DCCP_DEBUG
7690af3f ACM	63	const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
7690af3f ACM	64	"CLIENT rx opt: " : "server rx opt: ";
7c657876 ACM	65	#endif
	66	const struct dccp_hdr *dh = dccp_hdr(skb);
	67	const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type;
	68	unsigned char options = (unsigned char )dh + dccp_hdr_len(skb);
	69	unsigned char *opt_ptr = options;
7690af3f ACM	70	const unsigned char opt_end = (unsigned char )dh +
7690af3f ACM	71	(dh->dccph_doff * 4);
7c657876 ACM	72	struct dccp_options_received *opt_recv = &dp->dccps_options_received;
	73	unsigned char opt, len;
	74	unsigned char *value;
1c14ac0a	75	u32 elapsed_time;
afe00251 AB	76	int rc;
afe00251 AB	77	int mandatory = 0;
7c657876 ACM	78
	79	memset(opt_recv, 0, sizeof(*opt_recv));
	80
	81	while (opt_ptr != opt_end) {
	82	opt = *opt_ptr++;
	83	len = 0;
	84	value = NULL;
	85
	86	/* Check if this isn't a single byte option */
	87	if (opt > DCCPO_MAX_RESERVED) {
	88	if (opt_ptr == opt_end)
	89	goto out_invalid_option;
	90
	91	len = *opt_ptr++;
	92	if (len < 3)
	93	goto out_invalid_option;
	94	/*
	95	* Remove the type and len fields, leaving
	96	* just the value size
	97	*/
	98	len -= 2;
	99	value = opt_ptr;
	100	opt_ptr += len;
	101
	102	if (opt_ptr > opt_end)
	103	goto out_invalid_option;
	104	}
	105
	106	switch (opt) {
	107	case DCCPO_PADDING:
	108	break;
afe00251 AB	109	case DCCPO_MANDATORY:
	110	if (mandatory)
	111	goto out_invalid_option;
6df9424a ACM	112	if (pkt_type != DCCP_PKT_DATA)
6df9424a ACM	113	mandatory = 1;
afe00251	114	break;
7c657876 ACM	115	case DCCPO_NDP_COUNT:
	116	if (len > 3)
	117	goto out_invalid_option;
	118
	119	opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
7690af3f ACM	120	dccp_pr_debug("%sNDP count=%d\n", debug_prefix,
7690af3f ACM	121	opt_recv->dccpor_ndp);
7c657876	122	break;
afe00251 AB	123	case DCCPO_CHANGE_L:
	124	/* fall through */
	125	case DCCPO_CHANGE_R:
	126	if (len < 2)
	127	goto out_invalid_option;
	128	rc = dccp_feat_change_recv(sk, opt, *value, value + 1,
	129	len - 1);
	130	/*
	131	* When there is a change error, change_recv is
	132	* responsible for dealing with it. i.e. reply with an
	133	* empty confirm.
	134	* If the change was mandatory, then we need to die.
	135	*/
	136	if (rc && mandatory)
	137	goto out_invalid_option;
	138	break;
	139	case DCCPO_CONFIRM_L:
	140	/* fall through */
	141	case DCCPO_CONFIRM_R:
	142	if (len < 2)
	143	goto out_invalid_option;
	144	if (dccp_feat_confirm_recv(sk, opt, *value,
	145	value + 1, len - 1))
	146	goto out_invalid_option;
	147	break;
7c657876	148	case DCCPO_ACK_VECTOR_0:
ae31c339	149	case DCCPO_ACK_VECTOR_1:
7c657876	150	if (pkt_type == DCCP_PKT_DATA)
e5a6de91	151	break;
7c657876	152
ae31c339 ACM	153	if (dp->dccps_options.dccpo_send_ack_vector &&
	154	dccp_ackvec_parse(sk, skb, opt, value, len))
	155	goto out_invalid_option;
7c657876 ACM	156	break;
	157	case DCCPO_TIMESTAMP:
	158	if (len != 4)
	159	goto out_invalid_option;
	160
60fe62e7	161	opt_recv->dccpor_timestamp = ntohl((__be32 )value);
7c657876 ACM	162
7c657876 ACM	163	dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp;
b0e56780	164	dccp_timestamp(sk, &dp->dccps_timestamp_time);
7c657876 ACM	165
	166	dccp_pr_debug("%sTIMESTAMP=%u, ackno=%llu\n",
	167	debug_prefix, opt_recv->dccpor_timestamp,
f6ccf554	168	(unsigned long long)
7c657876 ACM	169	DCCP_SKB_CB(skb)->dccpd_ack_seq);
	170	break;
	171	case DCCPO_TIMESTAMP_ECHO:
1bc09869	172	if (len != 4 && len != 6 && len != 8)
7c657876 ACM	173	goto out_invalid_option;
7c657876 ACM	174
60fe62e7	175	opt_recv->dccpor_timestamp_echo = ntohl((__be32 )value);
7c657876	176
1bc09869	177	dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, ackno=%llu, ",
7690af3f ACM	178	debug_prefix,
7690af3f ACM	179	opt_recv->dccpor_timestamp_echo,
f6ccf554 DM	180	len + 2,
f6ccf554 DM	181	(unsigned long long)
1bc09869 IM	182	DCCP_SKB_CB(skb)->dccpd_ack_seq);
1bc09869 IM	183
1bc09869	184
1c14ac0a ACM	185	if (len == 4)
	186	break;
	187
	188	if (len == 6)
60fe62e7	189	elapsed_time = ntohs((__be16 )(value + 4));
1c14ac0a	190	else
60fe62e7	191	elapsed_time = ntohl((__be32 )(value + 4));
1c14ac0a ACM	192
	193	/* Give precedence to the biggest ELAPSED_TIME */
	194	if (elapsed_time > opt_recv->dccpor_elapsed_time)
	195	opt_recv->dccpor_elapsed_time = elapsed_time;
7c657876 ACM	196	break;
7c657876 ACM	197	case DCCPO_ELAPSED_TIME:
1bc09869	198	if (len != 2 && len != 4)
7c657876 ACM	199	goto out_invalid_option;
	200
	201	if (pkt_type == DCCP_PKT_DATA)
	202	continue;
1bc09869 IM	203
1bc09869 IM	204	if (len == 2)
60fe62e7	205	elapsed_time = ntohs((__be16 )value);
1bc09869	206	else
60fe62e7	207	elapsed_time = ntohl((__be32 )value);
1c14ac0a ACM	208
	209	if (elapsed_time > opt_recv->dccpor_elapsed_time)
	210	opt_recv->dccpor_elapsed_time = elapsed_time;
1bc09869	211
7c657876	212	dccp_pr_debug("%sELAPSED_TIME=%d\n", debug_prefix,
1c14ac0a	213	elapsed_time);
7c657876 ACM	214	break;
	215	/*
	216	* From draft-ietf-dccp-spec-11.txt:
	217	*
7690af3f ACM	218	* Option numbers 128 through 191 are for
	219	* options sent from the HC-Sender to the
	220	* HC-Receiver; option numbers 192 through 255
	221	* are for options sent from the HC-Receiver to
	222	* the HC-Sender.
7c657876 ACM	223	*/
	224	case 128 ... 191: {
	225	const u16 idx = value - options;
	226
7690af3f ACM	227	if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
	228	opt, len, idx,
	229	value) != 0)
7c657876 ACM	230	goto out_invalid_option;
	231	}
	232	break;
	233	case 192 ... 255: {
	234	const u16 idx = value - options;
	235
7690af3f ACM	236	if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
	237	opt, len, idx,
	238	value) != 0)
7c657876 ACM	239	goto out_invalid_option;
	240	}
	241	break;
	242	default:
7690af3f ACM	243	pr_info("DCCP(%p): option %d(len=%d) not "
7690af3f ACM	244	"implemented, ignoring\n",
7c657876 ACM	245	sk, opt, len);
	246	break;
	247	}
afe00251 AB	248
	249	if (opt != DCCPO_MANDATORY)
	250	mandatory = 0;
7c657876 ACM	251	}
7c657876 ACM	252
6df9424a ACM	253	/* mandatory was the last byte in option list -> reset connection */
	254	if (mandatory)
	255	goto out_invalid_option;
	256
7c657876 ACM	257	return 0;
	258
	259	out_invalid_option:
	260	DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
	261	DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_OPTION_ERROR;
	262	pr_info("DCCP(%p): invalid option %d, len=%d\n", sk, opt, len);
	263	return -1;
	264	}
	265
b61fafc4 ACM	266	EXPORT_SYMBOL_GPL(dccp_parse_options);
b61fafc4 ACM	267
7c657876 ACM	268	static void dccp_encode_value_var(const u32 value, unsigned char *to,
	269	const unsigned int len)
	270	{
	271	if (len > 3)
	272	*to++ = (value & 0xFF000000) >> 24;
	273	if (len > 2)
	274	*to++ = (value & 0xFF0000) >> 16;
	275	if (len > 1)
	276	*to++ = (value & 0xFF00) >> 8;
	277	if (len > 0)
	278	*to++ = (value & 0xFF);
	279	}
	280
	281	static inline int dccp_ndp_len(const int ndp)
	282	{
	283	return likely(ndp <= 0xFF) ? 1 : ndp <= 0xFFFF ? 2 : 3;
	284	}
	285
2d0817d1	286	int dccp_insert_option(struct sock sk, struct sk_buff skb,
7c657876 ACM	287	const unsigned char option,
	288	const void *value, const unsigned char len)
	289	{
	290	unsigned char *to;
	291
2d0817d1 ACM	292	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN)
2d0817d1 ACM	293	return -1;
7c657876 ACM	294
	295	DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
	296
	297	to = skb_push(skb, len + 2);
	298	*to++ = option;
	299	*to++ = len + 2;
	300
	301	memcpy(to, value, len);
2d0817d1	302	return 0;
7c657876 ACM	303	}
	304
	305	EXPORT_SYMBOL_GPL(dccp_insert_option);
	306
2d0817d1	307	static int dccp_insert_option_ndp(struct sock sk, struct sk_buff skb)
7c657876 ACM	308	{
	309	struct dccp_sock *dp = dccp_sk(sk);
	310	int ndp = dp->dccps_ndp_count;
	311
	312	if (dccp_non_data_packet(skb))
	313	++dp->dccps_ndp_count;
	314	else
	315	dp->dccps_ndp_count = 0;
	316
	317	if (ndp > 0) {
	318	unsigned char *ptr;
	319	const int ndp_len = dccp_ndp_len(ndp);
	320	const int len = ndp_len + 2;
	321
	322	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
2d0817d1	323	return -1;
7c657876 ACM	324
	325	DCCP_SKB_CB(skb)->dccpd_opt_len += len;
	326
	327	ptr = skb_push(skb, len);
	328	*ptr++ = DCCPO_NDP_COUNT;
	329	*ptr++ = len;
	330	dccp_encode_value_var(ndp, ptr, ndp_len);
	331	}
2d0817d1 ACM	332
2d0817d1 ACM	333	return 0;
7c657876 ACM	334	}
	335
	336	static inline int dccp_elapsed_time_len(const u32 elapsed_time)
	337	{
b1c9fe7b	338	return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
7c657876 ACM	339	}
7c657876 ACM	340
2d0817d1 ACM	341	int dccp_insert_option_elapsed_time(struct sock sk, struct sk_buff skb,
2d0817d1 ACM	342	u32 elapsed_time)
7c657876	343	{
7c657876 ACM	344	const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
	345	const int len = 2 + elapsed_time_len;
	346	unsigned char *to;
	347
1bc09869	348	if (elapsed_time_len == 0)
2d0817d1	349	return 0;
7c657876	350
2d0817d1 ACM	351	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
2d0817d1 ACM	352	return -1;
7c657876 ACM	353
	354	DCCP_SKB_CB(skb)->dccpd_opt_len += len;
	355
	356	to = skb_push(skb, len);
	357	*to++ = DCCPO_ELAPSED_TIME;
	358	*to++ = len;
	359
1bc09869	360	if (elapsed_time_len == 2) {
60fe62e7	361	const __be16 var16 = htons((u16)elapsed_time);
1bc09869 IM	362	memcpy(to, &var16, 2);
1bc09869 IM	363	} else {
60fe62e7	364	const __be32 var32 = htonl(elapsed_time);
1bc09869 IM	365	memcpy(to, &var32, 4);
1bc09869 IM	366	}
7c657876	367
2d0817d1	368	return 0;
7c657876 ACM	369	}
7c657876 ACM	370
d4b81ff7	371	EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
7c657876	372
b0e56780 ACM	373	void dccp_timestamp(const struct sock sk, struct timeval tv)
	374	{
	375	const struct dccp_sock *dp = dccp_sk(sk);
	376
	377	do_gettimeofday(tv);
	378	tv->tv_sec -= dp->dccps_epoch.tv_sec;
	379	tv->tv_usec -= dp->dccps_epoch.tv_usec;
	380
	381	while (tv->tv_usec < 0) {
	382	tv->tv_sec--;
	383	tv->tv_usec += USEC_PER_SEC;
	384	}
	385	}
	386
	387	EXPORT_SYMBOL_GPL(dccp_timestamp);
	388
2d0817d1	389	int dccp_insert_option_timestamp(struct sock sk, struct sk_buff skb)
7c657876	390	{
1bc09869	391	struct timeval tv;
60fe62e7	392	__be32 now;
afe00251	393
b0e56780	394	dccp_timestamp(sk, &tv);
60fe62e7	395	now = htonl(timeval_usecs(&tv) / 10);
1bc09869 IM	396	/* yes this will overflow but that is the point as we want a
	397	* 10 usec 32 bit timer which mean it wraps every 11.9 hours */
	398
2d0817d1	399	return dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
7c657876 ACM	400	}
7c657876 ACM	401
d4b81ff7 ACM	402	EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp);
d4b81ff7 ACM	403
2d0817d1 ACM	404	static int dccp_insert_option_timestamp_echo(struct sock *sk,
2d0817d1 ACM	405	struct sk_buff *skb)
7c657876 ACM	406	{
7c657876 ACM	407	struct dccp_sock *dp = dccp_sk(sk);
b0e56780	408	struct timeval now;
60fe62e7	409	__be32 tstamp_echo;
b0e56780 ACM	410	u32 elapsed_time;
b0e56780 ACM	411	int len, elapsed_time_len;
7c657876 ACM	412	unsigned char *to;
7c657876 ACM	413
b0e56780 ACM	414	dccp_timestamp(sk, &now);
	415	elapsed_time = timeval_delta(&now, &dp->dccps_timestamp_time) / 10;
	416	elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
	417	len = 6 + elapsed_time_len;
	418
2d0817d1 ACM	419	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
2d0817d1 ACM	420	return -1;
7c657876 ACM	421
	422	DCCP_SKB_CB(skb)->dccpd_opt_len += len;
	423
	424	to = skb_push(skb, len);
	425	*to++ = DCCPO_TIMESTAMP_ECHO;
	426	*to++ = len;
	427
	428	tstamp_echo = htonl(dp->dccps_timestamp_echo);
	429	memcpy(to, &tstamp_echo, 4);
	430	to += 4;
afe00251	431
1bc09869	432	if (elapsed_time_len == 2) {
60fe62e7	433	const __be16 var16 = htons((u16)elapsed_time);
1bc09869 IM	434	memcpy(to, &var16, 2);
1bc09869 IM	435	} else if (elapsed_time_len == 4) {
60fe62e7	436	const __be32 var32 = htonl(elapsed_time);
1bc09869 IM	437	memcpy(to, &var32, 4);
1bc09869 IM	438	}
7c657876	439
7c657876	440	dp->dccps_timestamp_echo = 0;
1bc09869 IM	441	dp->dccps_timestamp_time.tv_sec = 0;
1bc09869 IM	442	dp->dccps_timestamp_time.tv_usec = 0;
2d0817d1	443	return 0;
7c657876 ACM	444	}
7c657876 ACM	445
afe00251 AB	446	static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat,
	447	u8 *val, u8 len)
	448	{
	449	u8 *to;
	450
	451	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 3 > DCCP_MAX_OPT_LEN) {
	452	LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small"
	453	" to insert feature %d option!\n", feat);
	454	return -1;
	455	}
	456
	457	DCCP_SKB_CB(skb)->dccpd_opt_len += len + 3;
	458
	459	to = skb_push(skb, len + 3);
	460	*to++ = type;
	461	*to++ = len + 3;
	462	*to++ = feat;
	463
	464	if (len)
	465	memcpy(to, val, len);
	466	dccp_pr_debug("option %d feat %d len %d\n", type, feat, len);
	467
	468	return 0;
	469	}
	470
2d0817d1	471	static int dccp_insert_options_feat(struct sock sk, struct sk_buff skb)
afe00251 AB	472	{
	473	struct dccp_sock *dp = dccp_sk(sk);
	474	struct dccp_opt_pend opt, next;
	475	int change = 0;
	476
	477	/* confirm any options [NN opts] */
	478	list_for_each_entry_safe(opt, next, &dp->dccps_options.dccpo_conf,
	479	dccpop_node) {
	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	}
	488	INIT_LIST_HEAD(&dp->dccps_options.dccpo_conf);
	489
	490	/* see which features we need to send */
	491	list_for_each_entry(opt, &dp->dccps_options.dccpo_pending,
	492	dccpop_node) {
	493	/* see if we need to send any confirm */
	494	if (opt->dccpop_sc) {
	495	dccp_insert_feat_opt(skb, opt->dccpop_type + 1,
	496	opt->dccpop_feat,
	497	opt->dccpop_sc->dccpoc_val,
	498	opt->dccpop_sc->dccpoc_len);
	499
	500	BUG_ON(!opt->dccpop_sc->dccpoc_val);
	501	kfree(opt->dccpop_sc->dccpoc_val);
	502	kfree(opt->dccpop_sc);
	503	opt->dccpop_sc = NULL;
	504	}
	505
	506	/* any option not confirmed, re-send it */
	507	if (!opt->dccpop_conf) {
	508	dccp_insert_feat_opt(skb, opt->dccpop_type,
	509	opt->dccpop_feat, opt->dccpop_val,
	510	opt->dccpop_len);
	511	change++;
	512	}
	513	}
	514
	515	/* Retransmit timer.
	516	* If this is the master listening sock, we don't set a timer on it. It
	517	* should be fine because if the dude doesn't receive our RESPONSE
	518	* [which will contain the CHANGE] he will send another REQUEST which
	519	* will "retrnasmit" the change.
	520	*/
	521	if (change && dp->dccps_role != DCCP_ROLE_LISTEN) {
	522	dccp_pr_debug("reset feat negotiation timer %p\n", sk);
	523
	524	/* XXX don't reset the timer on re-transmissions. I.e. reset it
	525	* only when sending new stuff i guess. Currently the timer
	526	* never backs off because on re-transmission it just resets it!
	527	*/
	528	inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
	529	inet_csk(sk)->icsk_rto, DCCP_RTO_MAX);
	530	}
2d0817d1 ACM	531
2d0817d1 ACM	532	return 0;
afe00251 AB	533	}
afe00251 AB	534
2d0817d1	535	int dccp_insert_options(struct sock sk, struct sk_buff skb)
7c657876 ACM	536	{
	537	struct dccp_sock *dp = dccp_sk(sk);
	538
	539	DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
	540
2d0817d1 ACM	541	if (dp->dccps_options.dccpo_send_ndp_count &&
	542	dccp_insert_option_ndp(sk, skb))
	543	return -1;
7c657876 ACM	544
	545	if (!dccp_packet_without_ack(skb)) {
	546	if (dp->dccps_options.dccpo_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	}