/spare/repo/libata-dev branch 'master'

1 files changed, 398 insertions, 0 deletions

diff --git a/net/dccp/ccids/lib/packet_history.c b/net/dccp/ccids/lib/packet_history.c
new file mode 100644
index 00000000000..d3f9d205383
--- /dev/null
+++ b/net/dccp/ccids/lib/packet_history.c
@@ -0,0 +1,398 @@
+/*
+ *  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");