[GitHub/mt8127/android_kernel_alcatel_ttab.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;
			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)
				continue;

			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;
	}

	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;
}

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;
}

void 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) {
		LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to insert "
			       "%d option!\n", option);
		return;
	}

	DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;

	to    = skb_push(skb, len + 2);
	*to++ = option;
	*to++ = len + 2;

	memcpy(to, value, len);
}

EXPORT_SYMBOL_GPL(dccp_insert_option);

static void 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;

		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);
	}
}

static inline int dccp_elapsed_time_len(const u32 elapsed_time)
{
	return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
}

void dccp_insert_option_elapsed_time(struct sock *sk,
				     struct sk_buff *skb,
				     u32 elapsed_time)
{
#ifdef CONFIG_IP_DCCP_DEBUG
	struct dccp_sock *dp = dccp_sk(sk);
	const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
					"CLIENT TX opt: " : "server TX opt: ";
#endif
	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;

	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) {
		LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to "
					 "insert elapsed time!\n");
		return;
	}

	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);
	}

	dccp_pr_debug("%sELAPSED_TIME=%u, len=%d, seqno=%llu\n",
		      debug_prefix, elapsed_time,
		      len,
		      (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
}

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);

void 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 */

	dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
}

EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp);

static void dccp_insert_option_timestamp_echo(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 TX opt: " : "server TX opt: ";
#endif
	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) {
		LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to insert "
					 "timestamp echo!\n");
		return;
	}

	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);
	}

	dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, seqno=%llu\n",
		      debug_prefix, dp->dccps_timestamp_echo,
		      len,
		      (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);

	dp->dccps_timestamp_echo = 0;
	dp->dccps_timestamp_time.tv_sec = 0;
	dp->dccps_timestamp_time.tv_usec = 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 void dccp_insert_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);
	}
}

void 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);

	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);
		if (dp->dccps_timestamp_echo != 0)
			dccp_insert_option_timestamp_echo(sk, skb);
	}

	if (dp->dccps_hc_rx_insert_options) {
		ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb);
		dp->dccps_hc_rx_insert_options = 0;
	}
	if (dp->dccps_hc_tx_insert_options) {
		ccid_hc_tx_insert_options(dp->dccps_hc_tx_ccid, sk, skb);
		dp->dccps_hc_tx_insert_options = 0;
	}

	/* Feature negotiation */
	switch(DCCP_SKB_CB(skb)->dccpd_type) {
		/* Data packets can't do feat negotiation */
	case DCCP_PKT_DATA:
	case DCCP_PKT_DATAACK:
		break;
	default:
		dccp_insert_feat(sk, skb);
		break;
	}

	/* 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;
		}
	}
}
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;
	112	mandatory = 1;
	113	break;
7c657876 ACM	114	case DCCPO_NDP_COUNT:
	115	if (len > 3)
	116	goto out_invalid_option;
	117
	118	opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
7690af3f ACM	119	dccp_pr_debug("%sNDP count=%d\n", debug_prefix,
7690af3f ACM	120	opt_recv->dccpor_ndp);
7c657876	121	break;
afe00251 AB	122	case DCCPO_CHANGE_L:
	123	/* fall through */
	124	case DCCPO_CHANGE_R:
	125	if (len < 2)
	126	goto out_invalid_option;
	127	rc = dccp_feat_change_recv(sk, opt, *value, value + 1,
	128	len - 1);
	129	/*
	130	* When there is a change error, change_recv is
	131	* responsible for dealing with it. i.e. reply with an
	132	* empty confirm.
	133	* If the change was mandatory, then we need to die.
	134	*/
	135	if (rc && mandatory)
	136	goto out_invalid_option;
	137	break;
	138	case DCCPO_CONFIRM_L:
	139	/* fall through */
	140	case DCCPO_CONFIRM_R:
	141	if (len < 2)
	142	goto out_invalid_option;
	143	if (dccp_feat_confirm_recv(sk, opt, *value,
	144	value + 1, len - 1))
	145	goto out_invalid_option;
	146	break;
7c657876	147	case DCCPO_ACK_VECTOR_0:
ae31c339	148	case DCCPO_ACK_VECTOR_1:
7c657876 ACM	149	if (pkt_type == DCCP_PKT_DATA)
	150	continue;
	151
ae31c339 ACM	152	if (dp->dccps_options.dccpo_send_ack_vector &&
	153	dccp_ackvec_parse(sk, skb, opt, value, len))
	154	goto out_invalid_option;
7c657876 ACM	155	break;
	156	case DCCPO_TIMESTAMP:
	157	if (len != 4)
	158	goto out_invalid_option;
	159
60fe62e7	160	opt_recv->dccpor_timestamp = ntohl((__be32 )value);
7c657876 ACM	161
7c657876 ACM	162	dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp;
b0e56780	163	dccp_timestamp(sk, &dp->dccps_timestamp_time);
7c657876 ACM	164
	165	dccp_pr_debug("%sTIMESTAMP=%u, ackno=%llu\n",
	166	debug_prefix, opt_recv->dccpor_timestamp,
f6ccf554	167	(unsigned long long)
7c657876 ACM	168	DCCP_SKB_CB(skb)->dccpd_ack_seq);
	169	break;
	170	case DCCPO_TIMESTAMP_ECHO:
1bc09869	171	if (len != 4 && len != 6 && len != 8)
7c657876 ACM	172	goto out_invalid_option;
7c657876 ACM	173
60fe62e7	174	opt_recv->dccpor_timestamp_echo = ntohl((__be32 )value);
7c657876	175
1bc09869	176	dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, ackno=%llu, ",
7690af3f ACM	177	debug_prefix,
7690af3f ACM	178	opt_recv->dccpor_timestamp_echo,
f6ccf554 DM	179	len + 2,
f6ccf554 DM	180	(unsigned long long)
1bc09869 IM	181	DCCP_SKB_CB(skb)->dccpd_ack_seq);
1bc09869 IM	182
1bc09869	183
1c14ac0a ACM	184	if (len == 4)
	185	break;
	186
	187	if (len == 6)
60fe62e7	188	elapsed_time = ntohs((__be16 )(value + 4));
1c14ac0a	189	else
60fe62e7	190	elapsed_time = ntohl((__be32 )(value + 4));
1c14ac0a ACM	191
	192	/* Give precedence to the biggest ELAPSED_TIME */
	193	if (elapsed_time > opt_recv->dccpor_elapsed_time)
	194	opt_recv->dccpor_elapsed_time = elapsed_time;
7c657876 ACM	195	break;
7c657876 ACM	196	case DCCPO_ELAPSED_TIME:
1bc09869	197	if (len != 2 && len != 4)
7c657876 ACM	198	goto out_invalid_option;
	199
	200	if (pkt_type == DCCP_PKT_DATA)
	201	continue;
1bc09869 IM	202
1bc09869 IM	203	if (len == 2)
60fe62e7	204	elapsed_time = ntohs((__be16 )value);
1bc09869	205	else
60fe62e7	206	elapsed_time = ntohl((__be32 )value);
1c14ac0a ACM	207
	208	if (elapsed_time > opt_recv->dccpor_elapsed_time)
	209	opt_recv->dccpor_elapsed_time = elapsed_time;
1bc09869	210
7c657876	211	dccp_pr_debug("%sELAPSED_TIME=%d\n", debug_prefix,
1c14ac0a	212	elapsed_time);
7c657876 ACM	213	break;
	214	/*
	215	* From draft-ietf-dccp-spec-11.txt:
	216	*
7690af3f ACM	217	* Option numbers 128 through 191 are for
	218	* options sent from the HC-Sender to the
	219	* HC-Receiver; option numbers 192 through 255
	220	* are for options sent from the HC-Receiver to
	221	* the HC-Sender.
7c657876 ACM	222	*/
	223	case 128 ... 191: {
	224	const u16 idx = value - options;
	225
7690af3f ACM	226	if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
	227	opt, len, idx,
	228	value) != 0)
7c657876 ACM	229	goto out_invalid_option;
	230	}
	231	break;
	232	case 192 ... 255: {
	233	const u16 idx = value - options;
	234
7690af3f ACM	235	if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
	236	opt, len, idx,
	237	value) != 0)
7c657876 ACM	238	goto out_invalid_option;
	239	}
	240	break;
	241	default:
7690af3f ACM	242	pr_info("DCCP(%p): option %d(len=%d) not "
7690af3f ACM	243	"implemented, ignoring\n",
7c657876 ACM	244	sk, opt, len);
	245	break;
	246	}
afe00251 AB	247
	248	if (opt != DCCPO_MANDATORY)
	249	mandatory = 0;
7c657876 ACM	250	}
	251
	252	return 0;
	253
	254	out_invalid_option:
	255	DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
	256	DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_OPTION_ERROR;
	257	pr_info("DCCP(%p): invalid option %d, len=%d\n", sk, opt, len);
	258	return -1;
	259	}
	260
	261	static void dccp_encode_value_var(const u32 value, unsigned char *to,
	262	const unsigned int len)
	263	{
	264	if (len > 3)
	265	*to++ = (value & 0xFF000000) >> 24;
	266	if (len > 2)
	267	*to++ = (value & 0xFF0000) >> 16;
	268	if (len > 1)
	269	*to++ = (value & 0xFF00) >> 8;
	270	if (len > 0)
	271	*to++ = (value & 0xFF);
	272	}
	273
	274	static inline int dccp_ndp_len(const int ndp)
	275	{
	276	return likely(ndp <= 0xFF) ? 1 : ndp <= 0xFFFF ? 2 : 3;
	277	}
	278
	279	void dccp_insert_option(struct sock sk, struct sk_buff skb,
	280	const unsigned char option,
	281	const void *value, const unsigned char len)
	282	{
	283	unsigned char *to;
	284
	285	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN) {
7690af3f ACM	286	LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to insert "
7690af3f ACM	287	"%d option!\n", option);
7c657876 ACM	288	return;
	289	}
	290
	291	DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
	292
	293	to = skb_push(skb, len + 2);
	294	*to++ = option;
	295	*to++ = len + 2;
	296
	297	memcpy(to, value, len);
	298	}
	299
	300	EXPORT_SYMBOL_GPL(dccp_insert_option);
	301
	302	static void dccp_insert_option_ndp(struct sock sk, struct sk_buff skb)
	303	{
	304	struct dccp_sock *dp = dccp_sk(sk);
	305	int ndp = dp->dccps_ndp_count;
	306
	307	if (dccp_non_data_packet(skb))
	308	++dp->dccps_ndp_count;
	309	else
	310	dp->dccps_ndp_count = 0;
	311
	312	if (ndp > 0) {
	313	unsigned char *ptr;
	314	const int ndp_len = dccp_ndp_len(ndp);
	315	const int len = ndp_len + 2;
	316
	317	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
	318	return;
	319
	320	DCCP_SKB_CB(skb)->dccpd_opt_len += len;
	321
	322	ptr = skb_push(skb, len);
	323	*ptr++ = DCCPO_NDP_COUNT;
	324	*ptr++ = len;
	325	dccp_encode_value_var(ndp, ptr, ndp_len);
	326	}
	327	}
	328
	329	static inline int dccp_elapsed_time_len(const u32 elapsed_time)
	330	{
b1c9fe7b	331	return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
7c657876 ACM	332	}
	333
	334	void dccp_insert_option_elapsed_time(struct sock *sk,
	335	struct sk_buff *skb,
	336	u32 elapsed_time)
	337	{
725ba8ee	338	#ifdef CONFIG_IP_DCCP_DEBUG
7c657876	339	struct dccp_sock *dp = dccp_sk(sk);
7690af3f ACM	340	const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
7690af3f ACM	341	"CLIENT TX opt: " : "server TX opt: ";
7c657876 ACM	342	#endif
	343	const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
	344	const int len = 2 + elapsed_time_len;
	345	unsigned char *to;
	346
1bc09869	347	if (elapsed_time_len == 0)
7c657876 ACM	348	return;
	349
	350	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) {
7690af3f ACM	351	LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to "
7690af3f ACM	352	"insert elapsed time!\n");
7c657876 ACM	353	return;
	354	}
	355
	356	DCCP_SKB_CB(skb)->dccpd_opt_len += len;
	357
	358	to = skb_push(skb, len);
	359	*to++ = DCCPO_ELAPSED_TIME;
	360	*to++ = len;
	361
1bc09869	362	if (elapsed_time_len == 2) {
60fe62e7	363	const __be16 var16 = htons((u16)elapsed_time);
1bc09869 IM	364	memcpy(to, &var16, 2);
1bc09869 IM	365	} else {
60fe62e7	366	const __be32 var32 = htonl(elapsed_time);
1bc09869 IM	367	memcpy(to, &var32, 4);
1bc09869 IM	368	}
7c657876 ACM	369
	370	dccp_pr_debug("%sELAPSED_TIME=%u, len=%d, seqno=%llu\n",
	371	debug_prefix, elapsed_time,
f6ccf554 DM	372	len,
f6ccf554 DM	373	(unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
7c657876 ACM	374	}
7c657876 ACM	375
d4b81ff7	376	EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
7c657876	377
b0e56780 ACM	378	void dccp_timestamp(const struct sock sk, struct timeval tv)
	379	{
	380	const struct dccp_sock *dp = dccp_sk(sk);
	381
	382	do_gettimeofday(tv);
	383	tv->tv_sec -= dp->dccps_epoch.tv_sec;
	384	tv->tv_usec -= dp->dccps_epoch.tv_usec;
	385
	386	while (tv->tv_usec < 0) {
	387	tv->tv_sec--;
	388	tv->tv_usec += USEC_PER_SEC;
	389	}
	390	}
	391
	392	EXPORT_SYMBOL_GPL(dccp_timestamp);
	393
d4b81ff7	394	void dccp_insert_option_timestamp(struct sock sk, struct sk_buff skb)
7c657876	395	{
1bc09869	396	struct timeval tv;
60fe62e7	397	__be32 now;
afe00251	398
b0e56780	399	dccp_timestamp(sk, &tv);
60fe62e7	400	now = htonl(timeval_usecs(&tv) / 10);
1bc09869 IM	401	/* yes this will overflow but that is the point as we want a
	402	* 10 usec 32 bit timer which mean it wraps every 11.9 hours */
	403
7c657876 ACM	404	dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
	405	}
	406
d4b81ff7 ACM	407	EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp);
d4b81ff7 ACM	408
7690af3f ACM	409	static void dccp_insert_option_timestamp_echo(struct sock *sk,
7690af3f ACM	410	struct sk_buff *skb)
7c657876 ACM	411	{
7c657876 ACM	412	struct dccp_sock *dp = dccp_sk(sk);
725ba8ee	413	#ifdef CONFIG_IP_DCCP_DEBUG
7690af3f ACM	414	const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
7690af3f ACM	415	"CLIENT TX opt: " : "server TX opt: ";
7c657876	416	#endif
b0e56780	417	struct timeval now;
60fe62e7	418	__be32 tstamp_echo;
b0e56780 ACM	419	u32 elapsed_time;
b0e56780 ACM	420	int len, elapsed_time_len;
7c657876 ACM	421	unsigned char *to;
7c657876 ACM	422
b0e56780 ACM	423	dccp_timestamp(sk, &now);
	424	elapsed_time = timeval_delta(&now, &dp->dccps_timestamp_time) / 10;
	425	elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
	426	len = 6 + elapsed_time_len;
	427
7c657876	428	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) {
7690af3f ACM	429	LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to insert "
7690af3f ACM	430	"timestamp echo!\n");
7c657876 ACM	431	return;
	432	}
	433
	434	DCCP_SKB_CB(skb)->dccpd_opt_len += len;
	435
	436	to = skb_push(skb, len);
	437	*to++ = DCCPO_TIMESTAMP_ECHO;
	438	*to++ = len;
	439
	440	tstamp_echo = htonl(dp->dccps_timestamp_echo);
	441	memcpy(to, &tstamp_echo, 4);
	442	to += 4;
afe00251	443
1bc09869	444	if (elapsed_time_len == 2) {
60fe62e7	445	const __be16 var16 = htons((u16)elapsed_time);
1bc09869 IM	446	memcpy(to, &var16, 2);
1bc09869 IM	447	} else if (elapsed_time_len == 4) {
60fe62e7	448	const __be32 var32 = htonl(elapsed_time);
1bc09869 IM	449	memcpy(to, &var32, 4);
1bc09869 IM	450	}
7c657876 ACM	451
	452	dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, seqno=%llu\n",
	453	debug_prefix, dp->dccps_timestamp_echo,
f6ccf554 DM	454	len,
f6ccf554 DM	455	(unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
7c657876 ACM	456
7c657876 ACM	457	dp->dccps_timestamp_echo = 0;
1bc09869 IM	458	dp->dccps_timestamp_time.tv_sec = 0;
1bc09869 IM	459	dp->dccps_timestamp_time.tv_usec = 0;
7c657876 ACM	460	}
7c657876 ACM	461
afe00251 AB	462	static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat,
	463	u8 *val, u8 len)
	464	{
	465	u8 *to;
	466
	467	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 3 > DCCP_MAX_OPT_LEN) {
	468	LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small"
	469	" to insert feature %d option!\n", feat);
	470	return -1;
	471	}
	472
	473	DCCP_SKB_CB(skb)->dccpd_opt_len += len + 3;
	474
	475	to = skb_push(skb, len + 3);
	476	*to++ = type;
	477	*to++ = len + 3;
	478	*to++ = feat;
	479
	480	if (len)
	481	memcpy(to, val, len);
	482	dccp_pr_debug("option %d feat %d len %d\n", type, feat, len);
	483
	484	return 0;
	485	}
	486
	487	static void dccp_insert_feat(struct sock sk, struct sk_buff skb)
	488	{
	489	struct dccp_sock *dp = dccp_sk(sk);
	490	struct dccp_opt_pend opt, next;
	491	int change = 0;
	492
	493	/* confirm any options [NN opts] */
	494	list_for_each_entry_safe(opt, next, &dp->dccps_options.dccpo_conf,
	495	dccpop_node) {
	496	dccp_insert_feat_opt(skb, opt->dccpop_type,
	497	opt->dccpop_feat, opt->dccpop_val,
	498	opt->dccpop_len);
	499	/* fear empty confirms */
	500	if (opt->dccpop_val)
	501	kfree(opt->dccpop_val);
	502	kfree(opt);
	503	}
	504	INIT_LIST_HEAD(&dp->dccps_options.dccpo_conf);
	505
	506	/* see which features we need to send */
	507	list_for_each_entry(opt, &dp->dccps_options.dccpo_pending,
	508	dccpop_node) {
	509	/* see if we need to send any confirm */
	510	if (opt->dccpop_sc) {
	511	dccp_insert_feat_opt(skb, opt->dccpop_type + 1,
	512	opt->dccpop_feat,
	513	opt->dccpop_sc->dccpoc_val,
	514	opt->dccpop_sc->dccpoc_len);
	515
	516	BUG_ON(!opt->dccpop_sc->dccpoc_val);
	517	kfree(opt->dccpop_sc->dccpoc_val);
	518	kfree(opt->dccpop_sc);
	519	opt->dccpop_sc = NULL;
	520	}
	521
	522	/* any option not confirmed, re-send it */
	523	if (!opt->dccpop_conf) {
	524	dccp_insert_feat_opt(skb, opt->dccpop_type,
	525	opt->dccpop_feat, opt->dccpop_val,
526	opt->dccpop_len);
527	change++;
528	}
529	}
530
531	/* Retransmit timer.
532	* If this is the master listening sock, we don't set a timer on it. It
533	* should be fine because if the dude doesn't receive our RESPONSE
534	* [which will contain the CHANGE] he will send another REQUEST which
535	* will "retrnasmit" the change.
536	*/
537	if (change && dp->dccps_role != DCCP_ROLE_LISTEN) {
538	dccp_pr_debug("reset feat negotiation timer %p\n", sk);
539
540	/* XXX don't reset the timer on re-transmissions. I.e. reset it
541	* only when sending new stuff i guess. Currently the timer
542	* never backs off because on re-transmission it just resets it!
543	*/
544	inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
545	inet_csk(sk)->icsk_rto, DCCP_RTO_MAX);
546	}
547	}
548
7c657876 ACM	549	void dccp_insert_options(struct sock sk, struct sk_buff skb)
	550	{
	551	struct dccp_sock *dp = dccp_sk(sk);
	552
	553	DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
	554
	555	if (dp->dccps_options.dccpo_send_ndp_count)
	556	dccp_insert_option_ndp(sk, skb);
	557
	558	if (!dccp_packet_without_ack(skb)) {
	559	if (dp->dccps_options.dccpo_send_ack_vector &&
ae31c339 ACM	560	dccp_ackvec_pending(dp->dccps_hc_rx_ackvec))
ae31c339 ACM	561	dccp_insert_option_ackvec(sk, skb);
7c657876 ACM	562	if (dp->dccps_timestamp_echo != 0)
	563	dccp_insert_option_timestamp_echo(sk, skb);
	564	}
	565
507d37cf ACM	566	if (dp->dccps_hc_rx_insert_options) {
	567	ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb);
	568	dp->dccps_hc_rx_insert_options = 0;
	569	}
	570	if (dp->dccps_hc_tx_insert_options) {
	571	ccid_hc_tx_insert_options(dp->dccps_hc_tx_ccid, sk, skb);
	572	dp->dccps_hc_tx_insert_options = 0;
	573	}
7c657876	574
afe00251 AB	575	/* Feature negotiation */
	576	switch(DCCP_SKB_CB(skb)->dccpd_type) {
	577	/* Data packets can't do feat negotiation */
	578	case DCCP_PKT_DATA:
	579	case DCCP_PKT_DATAACK:
	580	break;
	581	default:
	582	dccp_insert_feat(sk, skb);
	583	break;
	584	}
	585
7c657876 ACM	586	/* XXX: insert other options when appropriate */
	587
	588	if (DCCP_SKB_CB(skb)->dccpd_opt_len != 0) {
	589	/* The length of all options has to be a multiple of 4 */
	590	int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4;
	591
	592	if (padding != 0) {
	593	padding = 4 - padding;
	594	memset(skb_push(skb, padding), 0, padding);
	595	DCCP_SKB_CB(skb)->dccpd_opt_len += padding;
	596	}
	597	}
	598	}