/*
- * net/dccp/packet_history.c
+ * net/dccp/packet_history.h
*
- * Copyright (c) 2005-6 The University of Waikato, Hamilton, New Zealand.
+ * 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 - ian.mcdonald@jandi.co.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:
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
+#include <linux/config.h>
#include <linux/module.h>
#include <linux/string.h>
EXPORT_SYMBOL_GPL(dccp_rx_hist_find_data_packet);
-void dccp_rx_hist_add_packet(struct dccp_rx_hist *hist,
+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,
- u64 nonloss_seqno)
+ struct dccp_rx_hist_entry *packet)
{
- struct dccp_rx_hist_entry *entry, *next;
+ struct dccp_rx_hist_entry *entry, *next, *iter;
u8 num_later = 0;
- list_add(&packet->dccphrx_node, rx_list);
+ 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) {
- if (after48(nonloss_seqno,
- entry->dccphrx_seqno)) {
- list_del_init(&entry->dccphrx_node);
- dccp_rx_hist_entry_delete(hist, entry);
- }
+ list_del_init(&entry->dccphrx_node);
+ dccp_rx_hist_entry_delete(hist, entry);
} else if (dccp_rx_hist_entry_data_packet(entry))
--num_later;
}
--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);
EXPORT_SYMBOL_GPL(dccp_tx_hist_find_entry);
-int dccp_rx_hist_find_entry(const struct list_head *list, const u64 seq,
- u8 *ccval)
-{
- struct dccp_rx_hist_entry *packet = NULL, *entry;
-
- list_for_each_entry(entry, list, dccphrx_node)
- if (entry->dccphrx_seqno == seq) {
- packet = entry;
- break;
- }
-
- if (packet)
- *ccval = packet->dccphrx_ccval;
-
- return packet != NULL;
-}
-
-EXPORT_SYMBOL_GPL(dccp_rx_hist_find_entry);
-
void dccp_tx_hist_purge_older(struct dccp_tx_hist *hist,
struct list_head *list,
struct dccp_tx_hist_entry *packet)
EXPORT_SYMBOL_GPL(dccp_tx_hist_purge);
-MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>, "
+MODULE_AUTHOR("Ian McDonald <iam4@cs.waikato.ac.nz>, "
"Arnaldo Carvalho de Melo <acme@ghostprotocols.net>");
MODULE_DESCRIPTION("DCCP TFRC library");
MODULE_LICENSE("GPL");
git://git.onelab.eu / linux-2.6.git / blobdiff