301 lines
7.6 KiB
C
301 lines
7.6 KiB
C
/*
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* net/dccp/packet_history.c
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*
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* Copyright (c) 2005-6 The University of Waikato, Hamilton, New Zealand.
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*
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* An implementation of the DCCP protocol
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*
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* This code has been developed by the University of Waikato WAND
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* research group. For further information please see http://www.wand.net.nz/
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* or e-mail Ian McDonald - ian.mcdonald@jandi.co.nz
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*
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* This code also uses code from Lulea University, rereleased as GPL by its
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* authors:
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* Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
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*
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* Changes to meet Linux coding standards, to make it meet latest ccid3 draft
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* and to make it work as a loadable module in the DCCP stack written by
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* Arnaldo Carvalho de Melo <acme@conectiva.com.br>.
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*
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* Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/module.h>
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#include <linux/string.h>
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#include "packet_history.h"
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/*
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* Transmitter History Routines
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*/
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struct dccp_tx_hist *dccp_tx_hist_new(const char *name)
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{
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struct dccp_tx_hist *hist = kmalloc(sizeof(*hist), GFP_ATOMIC);
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static const char dccp_tx_hist_mask[] = "tx_hist_%s";
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char *slab_name;
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if (hist == NULL)
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goto out;
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slab_name = kmalloc(strlen(name) + sizeof(dccp_tx_hist_mask) - 1,
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GFP_ATOMIC);
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if (slab_name == NULL)
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goto out_free_hist;
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sprintf(slab_name, dccp_tx_hist_mask, name);
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hist->dccptxh_slab = kmem_cache_create(slab_name,
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sizeof(struct dccp_tx_hist_entry),
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0, SLAB_HWCACHE_ALIGN,
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NULL, NULL);
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if (hist->dccptxh_slab == NULL)
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goto out_free_slab_name;
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out:
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return hist;
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out_free_slab_name:
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kfree(slab_name);
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out_free_hist:
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kfree(hist);
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hist = NULL;
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goto out;
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}
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EXPORT_SYMBOL_GPL(dccp_tx_hist_new);
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void dccp_tx_hist_delete(struct dccp_tx_hist *hist)
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{
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const char* name = kmem_cache_name(hist->dccptxh_slab);
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kmem_cache_destroy(hist->dccptxh_slab);
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kfree(name);
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kfree(hist);
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}
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EXPORT_SYMBOL_GPL(dccp_tx_hist_delete);
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struct dccp_tx_hist_entry *
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dccp_tx_hist_find_entry(const struct list_head *list, const u64 seq)
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{
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struct dccp_tx_hist_entry *packet = NULL, *entry;
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list_for_each_entry(entry, list, dccphtx_node)
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if (entry->dccphtx_seqno == seq) {
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packet = entry;
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break;
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}
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return packet;
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}
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EXPORT_SYMBOL_GPL(dccp_tx_hist_find_entry);
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void dccp_tx_hist_purge(struct dccp_tx_hist *hist, struct list_head *list)
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{
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struct dccp_tx_hist_entry *entry, *next;
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list_for_each_entry_safe(entry, next, list, dccphtx_node) {
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list_del_init(&entry->dccphtx_node);
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dccp_tx_hist_entry_delete(hist, entry);
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}
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}
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EXPORT_SYMBOL_GPL(dccp_tx_hist_purge);
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void dccp_tx_hist_purge_older(struct dccp_tx_hist *hist,
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struct list_head *list,
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struct dccp_tx_hist_entry *packet)
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{
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struct dccp_tx_hist_entry *next;
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list_for_each_entry_safe_continue(packet, next, list, dccphtx_node) {
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list_del_init(&packet->dccphtx_node);
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dccp_tx_hist_entry_delete(hist, packet);
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}
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}
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EXPORT_SYMBOL_GPL(dccp_tx_hist_purge_older);
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/*
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* Receiver History Routines
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*/
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struct dccp_rx_hist *dccp_rx_hist_new(const char *name)
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{
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struct dccp_rx_hist *hist = kmalloc(sizeof(*hist), GFP_ATOMIC);
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static const char dccp_rx_hist_mask[] = "rx_hist_%s";
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char *slab_name;
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if (hist == NULL)
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goto out;
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slab_name = kmalloc(strlen(name) + sizeof(dccp_rx_hist_mask) - 1,
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GFP_ATOMIC);
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if (slab_name == NULL)
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goto out_free_hist;
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sprintf(slab_name, dccp_rx_hist_mask, name);
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hist->dccprxh_slab = kmem_cache_create(slab_name,
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sizeof(struct dccp_rx_hist_entry),
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0, SLAB_HWCACHE_ALIGN,
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NULL, NULL);
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if (hist->dccprxh_slab == NULL)
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goto out_free_slab_name;
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out:
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return hist;
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out_free_slab_name:
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kfree(slab_name);
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out_free_hist:
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kfree(hist);
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hist = NULL;
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goto out;
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}
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EXPORT_SYMBOL_GPL(dccp_rx_hist_new);
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void dccp_rx_hist_delete(struct dccp_rx_hist *hist)
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{
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const char* name = kmem_cache_name(hist->dccprxh_slab);
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kmem_cache_destroy(hist->dccprxh_slab);
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kfree(name);
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kfree(hist);
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}
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EXPORT_SYMBOL_GPL(dccp_rx_hist_delete);
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int dccp_rx_hist_find_entry(const struct list_head *list, const u64 seq,
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u8 *ccval)
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{
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struct dccp_rx_hist_entry *packet = NULL, *entry;
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list_for_each_entry(entry, list, dccphrx_node)
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if (entry->dccphrx_seqno == seq) {
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packet = entry;
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break;
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}
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if (packet)
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*ccval = packet->dccphrx_ccval;
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return packet != NULL;
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}
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EXPORT_SYMBOL_GPL(dccp_rx_hist_find_entry);
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struct dccp_rx_hist_entry *
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dccp_rx_hist_find_data_packet(const struct list_head *list)
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{
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struct dccp_rx_hist_entry *entry, *packet = NULL;
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list_for_each_entry(entry, list, dccphrx_node)
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if (entry->dccphrx_type == DCCP_PKT_DATA ||
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entry->dccphrx_type == DCCP_PKT_DATAACK) {
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packet = entry;
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break;
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}
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return packet;
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}
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EXPORT_SYMBOL_GPL(dccp_rx_hist_find_data_packet);
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void dccp_rx_hist_add_packet(struct dccp_rx_hist *hist,
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struct list_head *rx_list,
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struct list_head *li_list,
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struct dccp_rx_hist_entry *packet,
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u64 nonloss_seqno)
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{
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struct dccp_rx_hist_entry *entry, *next;
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u8 num_later = 0;
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list_add(&packet->dccphrx_node, rx_list);
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num_later = TFRC_RECV_NUM_LATE_LOSS + 1;
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if (!list_empty(li_list)) {
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list_for_each_entry_safe(entry, next, rx_list, dccphrx_node) {
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if (num_later == 0) {
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if (after48(nonloss_seqno,
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entry->dccphrx_seqno)) {
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list_del_init(&entry->dccphrx_node);
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dccp_rx_hist_entry_delete(hist, entry);
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}
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} else if (dccp_rx_hist_entry_data_packet(entry))
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--num_later;
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}
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} else {
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int step = 0;
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u8 win_count = 0; /* Not needed, but lets shut up gcc */
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int tmp;
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/*
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* We have no loss interval history so we need at least one
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* rtt:s of data packets to approximate rtt.
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*/
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list_for_each_entry_safe(entry, next, rx_list, dccphrx_node) {
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if (num_later == 0) {
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switch (step) {
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case 0:
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step = 1;
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/* OK, find next data packet */
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num_later = 1;
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break;
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case 1:
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step = 2;
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/* OK, find next data packet */
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num_later = 1;
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win_count = entry->dccphrx_ccval;
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break;
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case 2:
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tmp = win_count - entry->dccphrx_ccval;
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if (tmp < 0)
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tmp += TFRC_WIN_COUNT_LIMIT;
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if (tmp > TFRC_WIN_COUNT_PER_RTT + 1) {
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/*
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* We have found a packet older
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* than one rtt remove the rest
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*/
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step = 3;
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} else /* OK, find next data packet */
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num_later = 1;
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break;
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case 3:
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list_del_init(&entry->dccphrx_node);
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dccp_rx_hist_entry_delete(hist, entry);
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break;
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}
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} else if (dccp_rx_hist_entry_data_packet(entry))
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--num_later;
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}
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}
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}
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EXPORT_SYMBOL_GPL(dccp_rx_hist_add_packet);
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void dccp_rx_hist_purge(struct dccp_rx_hist *hist, struct list_head *list)
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{
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struct dccp_rx_hist_entry *entry, *next;
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list_for_each_entry_safe(entry, next, list, dccphrx_node) {
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list_del_init(&entry->dccphrx_node);
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kmem_cache_free(hist->dccprxh_slab, entry);
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}
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}
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EXPORT_SYMBOL_GPL(dccp_rx_hist_purge);
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MODULE_AUTHOR("Ian McDonald <ian.mcdonald@jandi.co.nz>, "
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"Arnaldo Carvalho de Melo <acme@ghostprotocols.net>");
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MODULE_DESCRIPTION("DCCP TFRC library");
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MODULE_LICENSE("GPL");
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