linux_dsm_epyc7002/net/dccp/ccids/lib/packet_history.c
Arnaldo Carvalho de Melo d58d1af03a [TFRC]: Rename dccp_rx_ to tfrc_rx_
This is in preparation for merging the new rx history code written by Gerrit Renker.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:56:42 -08:00

298 lines
7.5 KiB
C

/*
* net/dccp/packet_history.c
*
* Copyright (c) 2007 The University of Aberdeen, Scotland, UK
* Copyright (c) 2005-7 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
*
* 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/string.h>
#include "packet_history.h"
/**
* tfrc_tx_hist_entry - Simple singly-linked TX history list
* @next: next oldest entry (LIFO order)
* @seqno: sequence number of this entry
* @stamp: send time of packet with sequence number @seqno
*/
struct tfrc_tx_hist_entry {
struct tfrc_tx_hist_entry *next;
u64 seqno;
ktime_t stamp;
};
/*
* Transmitter History Routines
*/
static struct kmem_cache *tfrc_tx_hist_slab;
static struct tfrc_tx_hist_entry *
tfrc_tx_hist_find_entry(struct tfrc_tx_hist_entry *head, u64 seqno)
{
while (head != NULL && head->seqno != seqno)
head = head->next;
return head;
}
int tfrc_tx_hist_add(struct tfrc_tx_hist_entry **headp, u64 seqno)
{
struct tfrc_tx_hist_entry *entry = kmem_cache_alloc(tfrc_tx_hist_slab, gfp_any());
if (entry == NULL)
return -ENOBUFS;
entry->seqno = seqno;
entry->stamp = ktime_get_real();
entry->next = *headp;
*headp = entry;
return 0;
}
EXPORT_SYMBOL_GPL(tfrc_tx_hist_add);
void tfrc_tx_hist_purge(struct tfrc_tx_hist_entry **headp)
{
struct tfrc_tx_hist_entry *head = *headp;
while (head != NULL) {
struct tfrc_tx_hist_entry *next = head->next;
kmem_cache_free(tfrc_tx_hist_slab, head);
head = next;
}
*headp = NULL;
}
EXPORT_SYMBOL_GPL(tfrc_tx_hist_purge);
u32 tfrc_tx_hist_rtt(struct tfrc_tx_hist_entry *head, const u64 seqno,
const ktime_t now)
{
u32 rtt = 0;
struct tfrc_tx_hist_entry *packet = tfrc_tx_hist_find_entry(head, seqno);
if (packet != NULL) {
rtt = ktime_us_delta(now, packet->stamp);
/*
* Garbage-collect older (irrelevant) entries:
*/
tfrc_tx_hist_purge(&packet->next);
}
return rtt;
}
EXPORT_SYMBOL_GPL(tfrc_tx_hist_rtt);
/*
* Receiver History Routines
*/
static struct kmem_cache *tfrc_rx_hist_slab;
struct tfrc_rx_hist_entry *tfrc_rx_hist_entry_new(const u32 ndp,
const struct sk_buff *skb,
const gfp_t prio)
{
struct tfrc_rx_hist_entry *entry = kmem_cache_alloc(tfrc_rx_hist_slab,
prio);
if (entry != NULL) {
const struct dccp_hdr *dh = dccp_hdr(skb);
entry->tfrchrx_seqno = DCCP_SKB_CB(skb)->dccpd_seq;
entry->tfrchrx_ccval = dh->dccph_ccval;
entry->tfrchrx_type = dh->dccph_type;
entry->tfrchrx_ndp = ndp;
entry->tfrchrx_tstamp = ktime_get_real();
}
return entry;
}
EXPORT_SYMBOL_GPL(tfrc_rx_hist_entry_new);
static inline void tfrc_rx_hist_entry_delete(struct tfrc_rx_hist_entry *entry)
{
kmem_cache_free(tfrc_rx_hist_slab, entry);
}
int tfrc_rx_hist_find_entry(const struct list_head *list, const u64 seq,
u8 *ccval)
{
struct tfrc_rx_hist_entry *packet = NULL, *entry;
list_for_each_entry(entry, list, tfrchrx_node)
if (entry->tfrchrx_seqno == seq) {
packet = entry;
break;
}
if (packet)
*ccval = packet->tfrchrx_ccval;
return packet != NULL;
}
EXPORT_SYMBOL_GPL(tfrc_rx_hist_find_entry);
struct tfrc_rx_hist_entry *
tfrc_rx_hist_find_data_packet(const struct list_head *list)
{
struct tfrc_rx_hist_entry *entry, *packet = NULL;
list_for_each_entry(entry, list, tfrchrx_node)
if (entry->tfrchrx_type == DCCP_PKT_DATA ||
entry->tfrchrx_type == DCCP_PKT_DATAACK) {
packet = entry;
break;
}
return packet;
}
EXPORT_SYMBOL_GPL(tfrc_rx_hist_find_data_packet);
void tfrc_rx_hist_add_packet(struct list_head *rx_list,
struct list_head *li_list,
struct tfrc_rx_hist_entry *packet,
u64 nonloss_seqno)
{
struct tfrc_rx_hist_entry *entry, *next;
u8 num_later = 0;
list_add(&packet->tfrchrx_node, rx_list);
num_later = TFRC_RECV_NUM_LATE_LOSS + 1;
if (!list_empty(li_list)) {
list_for_each_entry_safe(entry, next, rx_list, tfrchrx_node) {
if (num_later == 0) {
if (after48(nonloss_seqno,
entry->tfrchrx_seqno)) {
list_del_init(&entry->tfrchrx_node);
tfrc_rx_hist_entry_delete(entry);
}
} else if (tfrc_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, tfrchrx_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->tfrchrx_ccval;
break;
case 2:
tmp = win_count - entry->tfrchrx_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->tfrchrx_node);
tfrc_rx_hist_entry_delete(entry);
break;
}
} else if (tfrc_rx_hist_entry_data_packet(entry))
--num_later;
}
}
}
EXPORT_SYMBOL_GPL(tfrc_rx_hist_add_packet);
void tfrc_rx_hist_purge(struct list_head *list)
{
struct tfrc_rx_hist_entry *entry, *next;
list_for_each_entry_safe(entry, next, list, tfrchrx_node) {
list_del_init(&entry->tfrchrx_node);
tfrc_rx_hist_entry_delete(entry);
}
}
EXPORT_SYMBOL_GPL(tfrc_rx_hist_purge);
__init int packet_history_init(void)
{
tfrc_tx_hist_slab = kmem_cache_create("tfrc_tx_hist",
sizeof(struct tfrc_tx_hist_entry), 0,
SLAB_HWCACHE_ALIGN, NULL);
if (tfrc_tx_hist_slab == NULL)
goto out_err;
tfrc_rx_hist_slab = kmem_cache_create("tfrc_rx_hist",
sizeof(struct tfrc_rx_hist_entry), 0,
SLAB_HWCACHE_ALIGN, NULL);
if (tfrc_rx_hist_slab == NULL)
goto out_free_tx;
return 0;
out_free_tx:
kmem_cache_destroy(tfrc_tx_hist_slab);
tfrc_tx_hist_slab = NULL;
out_err:
return -ENOBUFS;
}
void packet_history_exit(void)
{
if (tfrc_tx_hist_slab != NULL) {
kmem_cache_destroy(tfrc_tx_hist_slab);
tfrc_tx_hist_slab = NULL;
}
if (tfrc_rx_hist_slab != NULL) {
kmem_cache_destroy(tfrc_rx_hist_slab);
tfrc_rx_hist_slab = NULL;
}
}