[deliverable/linux.git] / net / dccp / ccids / lib / packet_history.c

/*
 *  net/dccp/packet_history.h
 *
 *  Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
 *
 *  An implementation of the DCCP protocol
 *
 *  This code has been developed by the University of Waikato WAND
 *  research group. For further information please see http://www.wand.net.nz/
 *  or e-mail Ian McDonald - iam4@cs.waikato.ac.nz
 *
 *  This code also uses code from Lulea University, rereleased as GPL by its
 *  authors:
 *  Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
 *
 *  Changes to meet Linux coding standards, to make it meet latest ccid3 draft
 *  and to make it work as a loadable module in the DCCP stack written by
 *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>.
 *
 *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
 *
 *  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.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/string.h>

#include "packet_history.h"

struct dccp_rx_hist *dccp_rx_hist_new(const char *name)
{
	struct dccp_rx_hist *hist = kmalloc(sizeof(*hist), GFP_ATOMIC);
	static const char dccp_rx_hist_mask[] = "rx_hist_%s";
	char *slab_name;

	if (hist == NULL)
		goto out;

	slab_name = kmalloc(strlen(name) + sizeof(dccp_rx_hist_mask) - 1,
			    GFP_ATOMIC);
	if (slab_name == NULL)
		goto out_free_hist;

	sprintf(slab_name, dccp_rx_hist_mask, name);
	hist->dccprxh_slab = kmem_cache_create(slab_name,
					     sizeof(struct dccp_rx_hist_entry),
					       0, SLAB_HWCACHE_ALIGN,
					       NULL, NULL);
	if (hist->dccprxh_slab == NULL)
		goto out_free_slab_name;
out:
	return hist;
out_free_slab_name:
	kfree(slab_name);
out_free_hist:
	kfree(hist);
	hist = NULL;
	goto out;
}

EXPORT_SYMBOL_GPL(dccp_rx_hist_new);

void dccp_rx_hist_delete(struct dccp_rx_hist *hist)
{
	const char* name = kmem_cache_name(hist->dccprxh_slab);

	kmem_cache_destroy(hist->dccprxh_slab);
	kfree(name);
	kfree(hist);
}

EXPORT_SYMBOL_GPL(dccp_rx_hist_delete);

void dccp_rx_hist_purge(struct dccp_rx_hist *hist, struct list_head *list)
{
	struct dccp_rx_hist_entry *entry, *next;

	list_for_each_entry_safe(entry, next, list, dccphrx_node) {
		list_del_init(&entry->dccphrx_node);
		kmem_cache_free(hist->dccprxh_slab, entry);
	}
}

EXPORT_SYMBOL_GPL(dccp_rx_hist_purge);

struct dccp_rx_hist_entry *
		dccp_rx_hist_find_data_packet(const struct list_head *list)
{
	struct dccp_rx_hist_entry *entry, *packet = NULL;

	list_for_each_entry(entry, list, dccphrx_node)
		if (entry->dccphrx_type == DCCP_PKT_DATA ||
		    entry->dccphrx_type == DCCP_PKT_DATAACK) {
			packet = entry;
			break;
		}

	return packet;
}

EXPORT_SYMBOL_GPL(dccp_rx_hist_find_data_packet);

int dccp_rx_hist_add_packet(struct dccp_rx_hist *hist,
			    struct list_head *rx_list,
			    struct list_head *li_list,
			    struct dccp_rx_hist_entry *packet)
{
	struct dccp_rx_hist_entry *entry, *next, *iter;
	u8 num_later = 0;

	iter = dccp_rx_hist_head(rx_list);
	if (iter == NULL)
		dccp_rx_hist_add_entry(rx_list, packet);
	else {
		const u64 seqno = packet->dccphrx_seqno;

		if (after48(seqno, iter->dccphrx_seqno))
			dccp_rx_hist_add_entry(rx_list, packet);
		else {
			if (dccp_rx_hist_entry_data_packet(iter))
				num_later = 1;

			list_for_each_entry_continue(iter, rx_list,
						     dccphrx_node) {
				if (after48(seqno, iter->dccphrx_seqno)) {
					dccp_rx_hist_add_entry(&iter->dccphrx_node,
							       packet);
					goto trim_history;
				}

				if (dccp_rx_hist_entry_data_packet(iter))
					num_later++;

				if (num_later == TFRC_RECV_NUM_LATE_LOSS) {
					dccp_rx_hist_entry_delete(hist, packet);
					return 1;
				}
			}

			if (num_later < TFRC_RECV_NUM_LATE_LOSS)
				dccp_rx_hist_add_entry(rx_list, packet);
			/*
			 * FIXME: else what? should we destroy the packet
			 * like above?
			 */
		}
	}

trim_history:
	/*
	 * Trim history (remove all packets after the NUM_LATE_LOSS + 1
	 * data packets)
	 */
	num_later = TFRC_RECV_NUM_LATE_LOSS + 1;

	if (!list_empty(li_list)) {
		list_for_each_entry_safe(entry, next, rx_list, dccphrx_node) {
			if (num_later == 0) {
				list_del_init(&entry->dccphrx_node);
				dccp_rx_hist_entry_delete(hist, entry);
			} else if (dccp_rx_hist_entry_data_packet(entry))
				--num_later;
		}
	} else {
		int step = 0;
		u8 win_count = 0; /* Not needed, but lets shut up gcc */
		int tmp;
		/*
		 * We have no loss interval history so we need at least one
		 * rtt:s of data packets to approximate rtt.
		 */
		list_for_each_entry_safe(entry, next, rx_list, dccphrx_node) {
			if (num_later == 0) {
				switch (step) {
				case 0:
					step = 1;
					/* OK, find next data packet */
					num_later = 1;
					break;
				case 1:
					step = 2;
					/* OK, find next data packet */
					num_later = 1;
					win_count = entry->dccphrx_ccval;
					break;
				case 2:
					tmp = win_count - entry->dccphrx_ccval;
					if (tmp < 0)
						tmp += TFRC_WIN_COUNT_LIMIT;
					if (tmp > TFRC_WIN_COUNT_PER_RTT + 1) {
						/*
						 * We have found a packet older
						 * than one rtt remove the rest
						 */
						step = 3;
					} else /* OK, find next data packet */
						num_later = 1;
					break;
				case 3:
					list_del_init(&entry->dccphrx_node);
					dccp_rx_hist_entry_delete(hist, entry);
					break;
				}
			} else if (dccp_rx_hist_entry_data_packet(entry))
				--num_later;
		}
	}

	return 0;
}

EXPORT_SYMBOL_GPL(dccp_rx_hist_add_packet);

u64 dccp_rx_hist_detect_loss(struct list_head *rx_list,
			     struct list_head *li_list, u8 *win_loss)
{
	struct dccp_rx_hist_entry *entry, *next, *packet;
	struct dccp_rx_hist_entry *a_loss = NULL;
	struct dccp_rx_hist_entry *b_loss = NULL;
	u64 seq_loss = DCCP_MAX_SEQNO + 1;
	u8 num_later = TFRC_RECV_NUM_LATE_LOSS;

	list_for_each_entry_safe(entry, next, rx_list, dccphrx_node) {
		if (num_later == 0) {
			b_loss = entry;
			break;
		} else if (dccp_rx_hist_entry_data_packet(entry))
			--num_later;
	}

	if (b_loss == NULL)
		goto out;

	num_later = 1;
	list_for_each_entry_safe_continue(entry, next, rx_list, dccphrx_node) {
		if (num_later == 0) {
			a_loss = entry;
			break;
		} else if (dccp_rx_hist_entry_data_packet(entry))
			--num_later;
	}

	if (a_loss == NULL) {
		if (list_empty(li_list)) {
			/* no loss event have occured yet */
			LIMIT_NETDEBUG("%s: TODO: find a lost data packet by "
				       "comparing to initial seqno\n",
				       __FUNCTION__);
			goto out;
		} else {
			LIMIT_NETDEBUG("%s: Less than 4 data pkts in history!",
				       __FUNCTION__);
			goto out;
		}
	}

	/* Locate a lost data packet */
	entry = packet = b_loss;
	list_for_each_entry_safe_continue(entry, next, rx_list, dccphrx_node) {
		u64 delta = dccp_delta_seqno(entry->dccphrx_seqno,
					     packet->dccphrx_seqno);

		if (delta != 0) {
			if (dccp_rx_hist_entry_data_packet(packet))
				--delta;
			/*
			 * FIXME: check this, probably this % usage is because
			 * in earlier drafts the ndp count was just 8 bits
			 * long, but now it cam be up to 24 bits long.
			 */
#if 0
			if (delta % DCCP_NDP_LIMIT !=
			    (packet->dccphrx_ndp -
			     entry->dccphrx_ndp) % DCCP_NDP_LIMIT)
#endif
			if (delta != packet->dccphrx_ndp - entry->dccphrx_ndp) {
				seq_loss = entry->dccphrx_seqno;
				dccp_inc_seqno(&seq_loss);
			}
		}
		packet = entry;
		if (packet == a_loss)
			break;
	}
out:
	if (seq_loss != DCCP_MAX_SEQNO + 1)
		*win_loss = a_loss->dccphrx_ccval;
	else
		*win_loss = 0; /* Paranoia */

	return seq_loss;
}

EXPORT_SYMBOL_GPL(dccp_rx_hist_detect_loss);

struct dccp_tx_hist *dccp_tx_hist_new(const char *name)
{
	struct dccp_tx_hist *hist = kmalloc(sizeof(*hist), GFP_ATOMIC);
	static const char dccp_tx_hist_mask[] = "tx_hist_%s";
	char *slab_name;

	if (hist == NULL)
		goto out;

	slab_name = kmalloc(strlen(name) + sizeof(dccp_tx_hist_mask) - 1,
			    GFP_ATOMIC);
	if (slab_name == NULL)
		goto out_free_hist;

	sprintf(slab_name, dccp_tx_hist_mask, name);
	hist->dccptxh_slab = kmem_cache_create(slab_name,
					     sizeof(struct dccp_tx_hist_entry),
					       0, SLAB_HWCACHE_ALIGN,
					       NULL, NULL);
	if (hist->dccptxh_slab == NULL)
		goto out_free_slab_name;
out:
	return hist;
out_free_slab_name:
	kfree(slab_name);
out_free_hist:
	kfree(hist);
	hist = NULL;
	goto out;
}

EXPORT_SYMBOL_GPL(dccp_tx_hist_new);

void dccp_tx_hist_delete(struct dccp_tx_hist *hist)
{
	const char* name = kmem_cache_name(hist->dccptxh_slab);

	kmem_cache_destroy(hist->dccptxh_slab);
	kfree(name);
	kfree(hist);
}

EXPORT_SYMBOL_GPL(dccp_tx_hist_delete);

struct dccp_tx_hist_entry *
	dccp_tx_hist_find_entry(const struct list_head *list, const u64 seq)
{
	struct dccp_tx_hist_entry *packet = NULL, *entry;

	list_for_each_entry(entry, list, dccphtx_node)
		if (entry->dccphtx_seqno == seq) {
			packet = entry;
			break;
		}

	return packet;
}

EXPORT_SYMBOL_GPL(dccp_tx_hist_find_entry);

void dccp_tx_hist_purge_older(struct dccp_tx_hist *hist,
			      struct list_head *list,
			      struct dccp_tx_hist_entry *packet)
{
	struct dccp_tx_hist_entry *next;

	list_for_each_entry_safe_continue(packet, next, list, dccphtx_node) {
		list_del_init(&packet->dccphtx_node);
		dccp_tx_hist_entry_delete(hist, packet);
	}
}

EXPORT_SYMBOL_GPL(dccp_tx_hist_purge_older);

void dccp_tx_hist_purge(struct dccp_tx_hist *hist, struct list_head *list)
{
	struct dccp_tx_hist_entry *entry, *next;

	list_for_each_entry_safe(entry, next, list, dccphtx_node) {
		list_del_init(&entry->dccphtx_node);
		dccp_tx_hist_entry_delete(hist, entry);
	}
}

EXPORT_SYMBOL_GPL(dccp_tx_hist_purge);

MODULE_AUTHOR("Ian McDonald <iam4@cs.waikato.ac.nz>, "
	      "Arnaldo Carvalho de Melo <acme@ghostprotocols.net>");
MODULE_DESCRIPTION("DCCP TFRC library");
MODULE_LICENSE("GPL");
Commit	Line	Data
8c60f3fa ACM	1	/*
	2	* net/dccp/packet_history.h
	3	*
	4	* Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
	5	*
	6	* An implementation of the DCCP protocol
	7	*
	8	* This code has been developed by the University of Waikato WAND
	9	* research group. For further information please see http://www.wand.net.nz/
	10	* or e-mail Ian McDonald - iam4@cs.waikato.ac.nz
	11	*
	12	* This code also uses code from Lulea University, rereleased as GPL by its
	13	* authors:
	14	* Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
	15	*
	16	* Changes to meet Linux coding standards, to make it meet latest ccid3 draft
	17	* and to make it work as a loadable module in the DCCP stack written by
	18	* Arnaldo Carvalho de Melo <acme@conectiva.com.br>.
	19	*
	20	* Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
	21	*
	22	* This program is free software; you can redistribute it and/or modify
	23	* it under the terms of the GNU General Public License as published by
	24	* the Free Software Foundation; either version 2 of the License, or
	25	* (at your option) any later version.
	26	*
	27	* This program is distributed in the hope that it will be useful,
	28	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	29	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	30	* GNU General Public License for more details.
	31	*
	32	* You should have received a copy of the GNU General Public License
	33	* along with this program; if not, write to the Free Software
	34	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	35	*/
	36
	37	#include <linux/config.h>
5cea0ddc	38	#include <linux/module.h>
8c60f3fa ACM	39	#include <linux/string.h>
	40
	41	#include "packet_history.h"
	42
	43	struct dccp_rx_hist dccp_rx_hist_new(const char name)
	44	{
	45	struct dccp_rx_hist hist = kmalloc(sizeof(hist), GFP_ATOMIC);
	46	static const char dccp_rx_hist_mask[] = "rx_hist_%s";
	47	char *slab_name;
	48
	49	if (hist == NULL)
	50	goto out;
	51
	52	slab_name = kmalloc(strlen(name) + sizeof(dccp_rx_hist_mask) - 1,
	53	GFP_ATOMIC);
	54	if (slab_name == NULL)
	55	goto out_free_hist;
	56
	57	sprintf(slab_name, dccp_rx_hist_mask, name);
	58	hist->dccprxh_slab = kmem_cache_create(slab_name,
7690af3f	59	sizeof(struct dccp_rx_hist_entry),
8c60f3fa ACM	60	0, SLAB_HWCACHE_ALIGN,
	61	NULL, NULL);
	62	if (hist->dccprxh_slab == NULL)
	63	goto out_free_slab_name;
	64	out:
	65	return hist;
	66	out_free_slab_name:
	67	kfree(slab_name);
	68	out_free_hist:
	69	kfree(hist);
	70	hist = NULL;
	71	goto out;
	72	}
	73
	74	EXPORT_SYMBOL_GPL(dccp_rx_hist_new);
	75
	76	void dccp_rx_hist_delete(struct dccp_rx_hist *hist)
	77	{
	78	const char* name = kmem_cache_name(hist->dccprxh_slab);
	79
	80	kmem_cache_destroy(hist->dccprxh_slab);
	81	kfree(name);
	82	kfree(hist);
	83	}
	84
	85	EXPORT_SYMBOL_GPL(dccp_rx_hist_delete);
	86
	87	void dccp_rx_hist_purge(struct dccp_rx_hist hist, struct list_head list)
	88	{
	89	struct dccp_rx_hist_entry entry, next;
	90
	91	list_for_each_entry_safe(entry, next, list, dccphrx_node) {
	92	list_del_init(&entry->dccphrx_node);
	93	kmem_cache_free(hist->dccprxh_slab, entry);
	94	}
	95	}
	96
	97	EXPORT_SYMBOL_GPL(dccp_rx_hist_purge);
	98
	99	struct dccp_rx_hist_entry *
	100	dccp_rx_hist_find_data_packet(const struct list_head *list)
	101	{
	102	struct dccp_rx_hist_entry entry, packet = NULL;
	103
	104	list_for_each_entry(entry, list, dccphrx_node)
	105	if (entry->dccphrx_type == DCCP_PKT_DATA \|\|
	106	entry->dccphrx_type == DCCP_PKT_DATAACK) {
	107	packet = entry;
	108	break;
	109	}
	110
	111	return packet;
	112	}
	113
	114	EXPORT_SYMBOL_GPL(dccp_rx_hist_find_data_packet);
	115
072ab6c6 ACM	116	int dccp_rx_hist_add_packet(struct dccp_rx_hist *hist,
	117	struct list_head *rx_list,
	118	struct list_head *li_list,
	119	struct dccp_rx_hist_entry *packet)
	120	{
	121	struct dccp_rx_hist_entry entry, next, *iter;
	122	u8 num_later = 0;
	123
	124	iter = dccp_rx_hist_head(rx_list);
	125	if (iter == NULL)
	126	dccp_rx_hist_add_entry(rx_list, packet);
	127	else {
	128	const u64 seqno = packet->dccphrx_seqno;
	129
	130	if (after48(seqno, iter->dccphrx_seqno))
	131	dccp_rx_hist_add_entry(rx_list, packet);
	132	else {
	133	if (dccp_rx_hist_entry_data_packet(iter))
	134	num_later = 1;
	135
	136	list_for_each_entry_continue(iter, rx_list,
	137	dccphrx_node) {
	138	if (after48(seqno, iter->dccphrx_seqno)) {
	139	dccp_rx_hist_add_entry(&iter->dccphrx_node,
	140	packet);
	141	goto trim_history;
	142	}
	143
	144	if (dccp_rx_hist_entry_data_packet(iter))
	145	num_later++;
	146
	147	if (num_later == TFRC_RECV_NUM_LATE_LOSS) {
	148	dccp_rx_hist_entry_delete(hist, packet);
	149	return 1;
	150	}
	151	}
	152
	153	if (num_later < TFRC_RECV_NUM_LATE_LOSS)
	154	dccp_rx_hist_add_entry(rx_list, packet);
	155	/*
	156	* FIXME: else what? should we destroy the packet
	157	* like above?
	158	*/
	159	}
	160	}
	161
	162	trim_history:
	163	/*
	164	* Trim history (remove all packets after the NUM_LATE_LOSS + 1
	165	* data packets)
	166	*/
	167	num_later = TFRC_RECV_NUM_LATE_LOSS + 1;
	168
	169	if (!list_empty(li_list)) {
	170	list_for_each_entry_safe(entry, next, rx_list, dccphrx_node) {
	171	if (num_later == 0) {
	172	list_del_init(&entry->dccphrx_node);
	173	dccp_rx_hist_entry_delete(hist, entry);
	174	} else if (dccp_rx_hist_entry_data_packet(entry))
	175	--num_later;
	176	}
	177	} else {
	178	int step = 0;
	179	u8 win_count = 0; /* Not needed, but lets shut up gcc */
180	int tmp;
181	/*
182	* We have no loss interval history so we need at least one
183	* rtt:s of data packets to approximate rtt.
184	*/
185	list_for_each_entry_safe(entry, next, rx_list, dccphrx_node) {
186	if (num_later == 0) {
187	switch (step) {
188	case 0:
189	step = 1;
190	/* OK, find next data packet */
191	num_later = 1;
192	break;
193	case 1:
194	step = 2;
195	/* OK, find next data packet */
196	num_later = 1;
197	win_count = entry->dccphrx_ccval;
198	break;
199	case 2:
200	tmp = win_count - entry->dccphrx_ccval;
201	if (tmp < 0)
202	tmp += TFRC_WIN_COUNT_LIMIT;
203	if (tmp > TFRC_WIN_COUNT_PER_RTT + 1) {
204	/*
205	* We have found a packet older
206	* than one rtt remove the rest
207	*/
208	step = 3;
209	} else /* OK, find next data packet */
210	num_later = 1;
211	break;
212	case 3:
213	list_del_init(&entry->dccphrx_node);
214	dccp_rx_hist_entry_delete(hist, entry);
215	break;
216	}
217	} else if (dccp_rx_hist_entry_data_packet(entry))
218	--num_later;
219	}
220	}
221
222	return 0;
223	}
224
225	EXPORT_SYMBOL_GPL(dccp_rx_hist_add_packet);
226
29e4f8b3 ACM	227	u64 dccp_rx_hist_detect_loss(struct list_head *rx_list,
	228	struct list_head li_list, u8 win_loss)
	229	{
	230	struct dccp_rx_hist_entry entry, next, *packet;
	231	struct dccp_rx_hist_entry *a_loss = NULL;
	232	struct dccp_rx_hist_entry *b_loss = NULL;
	233	u64 seq_loss = DCCP_MAX_SEQNO + 1;
	234	u8 num_later = TFRC_RECV_NUM_LATE_LOSS;
	235
	236	list_for_each_entry_safe(entry, next, rx_list, dccphrx_node) {
	237	if (num_later == 0) {
	238	b_loss = entry;
	239	break;
	240	} else if (dccp_rx_hist_entry_data_packet(entry))
	241	--num_later;
	242	}
	243
	244	if (b_loss == NULL)
	245	goto out;
	246
	247	num_later = 1;
	248	list_for_each_entry_safe_continue(entry, next, rx_list, dccphrx_node) {
	249	if (num_later == 0) {
	250	a_loss = entry;
	251	break;
	252	} else if (dccp_rx_hist_entry_data_packet(entry))
	253	--num_later;
	254	}
	255
	256	if (a_loss == NULL) {
	257	if (list_empty(li_list)) {
	258	/* no loss event have occured yet */
	259	LIMIT_NETDEBUG("%s: TODO: find a lost data packet by "
	260	"comparing to initial seqno\n",
	261	__FUNCTION__);
	262	goto out;
	263	} else {
	264	LIMIT_NETDEBUG("%s: Less than 4 data pkts in history!",
	265	__FUNCTION__);
	266	goto out;
	267	}
	268	}
	269
	270	/* Locate a lost data packet */
	271	entry = packet = b_loss;
	272	list_for_each_entry_safe_continue(entry, next, rx_list, dccphrx_node) {
	273	u64 delta = dccp_delta_seqno(entry->dccphrx_seqno,
	274	packet->dccphrx_seqno);
	275
	276	if (delta != 0) {
	277	if (dccp_rx_hist_entry_data_packet(packet))
	278	--delta;
	279	/*
	280	* FIXME: check this, probably this % usage is because
	281	* in earlier drafts the ndp count was just 8 bits
	282	* long, but now it cam be up to 24 bits long.
	283	*/
	284	#if 0
	285	if (delta % DCCP_NDP_LIMIT !=
	286	(packet->dccphrx_ndp -
	287	entry->dccphrx_ndp) % DCCP_NDP_LIMIT)
	288	#endif
	289	if (delta != packet->dccphrx_ndp - entry->dccphrx_ndp) {
	290	seq_loss = entry->dccphrx_seqno;
291	dccp_inc_seqno(&seq_loss);
292	}
293	}
294	packet = entry;
295	if (packet == a_loss)
296	break;
297	}
298	out:
299	if (seq_loss != DCCP_MAX_SEQNO + 1)
300	*win_loss = a_loss->dccphrx_ccval;
301	else
302	win_loss = 0; / Paranoia */
303
304	return seq_loss;
305	}
306
307	EXPORT_SYMBOL_GPL(dccp_rx_hist_detect_loss);
308
8c60f3fa ACM	309	struct dccp_tx_hist dccp_tx_hist_new(const char name)
	310	{
	311	struct dccp_tx_hist hist = kmalloc(sizeof(hist), GFP_ATOMIC);
	312	static const char dccp_tx_hist_mask[] = "tx_hist_%s";
	313	char *slab_name;
	314
	315	if (hist == NULL)
	316	goto out;
	317
	318	slab_name = kmalloc(strlen(name) + sizeof(dccp_tx_hist_mask) - 1,
	319	GFP_ATOMIC);
	320	if (slab_name == NULL)
	321	goto out_free_hist;
	322
	323	sprintf(slab_name, dccp_tx_hist_mask, name);
	324	hist->dccptxh_slab = kmem_cache_create(slab_name,
7690af3f	325	sizeof(struct dccp_tx_hist_entry),
8c60f3fa ACM	326	0, SLAB_HWCACHE_ALIGN,
	327	NULL, NULL);
	328	if (hist->dccptxh_slab == NULL)
	329	goto out_free_slab_name;
	330	out:
	331	return hist;
	332	out_free_slab_name:
	333	kfree(slab_name);
	334	out_free_hist:
	335	kfree(hist);
	336	hist = NULL;
	337	goto out;
	338	}
	339
	340	EXPORT_SYMBOL_GPL(dccp_tx_hist_new);
	341
	342	void dccp_tx_hist_delete(struct dccp_tx_hist *hist)
	343	{
	344	const char* name = kmem_cache_name(hist->dccptxh_slab);
	345
	346	kmem_cache_destroy(hist->dccptxh_slab);
	347	kfree(name);
	348	kfree(hist);
	349	}
	350
	351	EXPORT_SYMBOL_GPL(dccp_tx_hist_delete);
	352
7690af3f ACM	353	struct dccp_tx_hist_entry *
7690af3f ACM	354	dccp_tx_hist_find_entry(const struct list_head *list, const u64 seq)
8c60f3fa ACM	355	{
	356	struct dccp_tx_hist_entry packet = NULL, entry;
	357
	358	list_for_each_entry(entry, list, dccphtx_node)
	359	if (entry->dccphtx_seqno == seq) {
	360	packet = entry;
	361	break;
	362	}
	363
	364	return packet;
	365	}
	366
	367	EXPORT_SYMBOL_GPL(dccp_tx_hist_find_entry);
	368
7690af3f ACM	369	void dccp_tx_hist_purge_older(struct dccp_tx_hist *hist,
7690af3f ACM	370	struct list_head *list,
8c60f3fa ACM	371	struct dccp_tx_hist_entry *packet)
	372	{
	373	struct dccp_tx_hist_entry *next;
	374
	375	list_for_each_entry_safe_continue(packet, next, list, dccphtx_node) {
	376	list_del_init(&packet->dccphtx_node);
	377	dccp_tx_hist_entry_delete(hist, packet);
	378	}
	379	}
	380
	381	EXPORT_SYMBOL_GPL(dccp_tx_hist_purge_older);
	382
	383	void dccp_tx_hist_purge(struct dccp_tx_hist hist, struct list_head list)
	384	{
	385	struct dccp_tx_hist_entry entry, next;
	386
	387	list_for_each_entry_safe(entry, next, list, dccphtx_node) {
	388	list_del_init(&entry->dccphtx_node);
	389	dccp_tx_hist_entry_delete(hist, entry);
	390	}
	391	}
	392
	393	EXPORT_SYMBOL_GPL(dccp_tx_hist_purge);
5cea0ddc ACM	394
	395	MODULE_AUTHOR("Ian McDonald <iam4@cs.waikato.ac.nz>, "
	396	"Arnaldo Carvalho de Melo <acme@ghostprotocols.net>");
	397	MODULE_DESCRIPTION("DCCP TFRC library");
	398	MODULE_LICENSE("GPL");