aboutsummaryrefslogtreecommitdiff
path: root/net/dccp/ccids/lib/packet_history.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/dccp/ccids/lib/packet_history.c')
-rw-r--r--net/dccp/ccids/lib/packet_history.c398
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");
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-15 16:00:40 +0000