diff options
Diffstat (limited to 'net/dccp/ccids/lib')
-rw-r--r-- | net/dccp/ccids/lib/Makefile | 3 | ||||
-rw-r--r-- | net/dccp/ccids/lib/loss_interval.c | 144 | ||||
-rw-r--r-- | net/dccp/ccids/lib/loss_interval.h | 61 | ||||
-rw-r--r-- | net/dccp/ccids/lib/packet_history.c | 398 | ||||
-rw-r--r-- | net/dccp/ccids/lib/packet_history.h | 199 | ||||
-rw-r--r-- | net/dccp/ccids/lib/tfrc.h | 22 | ||||
-rw-r--r-- | net/dccp/ccids/lib/tfrc_equation.c | 644 |
7 files changed, 1471 insertions, 0 deletions
diff --git a/net/dccp/ccids/lib/Makefile b/net/dccp/ccids/lib/Makefile new file mode 100644 index 0000000..5f940a6 --- /dev/null +++ b/net/dccp/ccids/lib/Makefile @@ -0,0 +1,3 @@ +obj-$(CONFIG_IP_DCCP_TFRC_LIB) += dccp_tfrc_lib.o + +dccp_tfrc_lib-y := loss_interval.o packet_history.o tfrc_equation.o diff --git a/net/dccp/ccids/lib/loss_interval.c b/net/dccp/ccids/lib/loss_interval.c new file mode 100644 index 0000000..4c01a54 --- /dev/null +++ b/net/dccp/ccids/lib/loss_interval.c @@ -0,0 +1,144 @@ +/* + * net/dccp/ccids/lib/loss_interval.c + * + * Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand. + * Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz> + * 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. + */ + +#include <linux/config.h> +#include <linux/module.h> + +#include "loss_interval.h" + +struct dccp_li_hist *dccp_li_hist_new(const char *name) +{ + struct dccp_li_hist *hist = kmalloc(sizeof(*hist), GFP_ATOMIC); + static const char dccp_li_hist_mask[] = "li_hist_%s"; + char *slab_name; + + if (hist == NULL) + goto out; + + slab_name = kmalloc(strlen(name) + sizeof(dccp_li_hist_mask) - 1, + GFP_ATOMIC); + if (slab_name == NULL) + goto out_free_hist; + + sprintf(slab_name, dccp_li_hist_mask, name); + hist->dccplih_slab = kmem_cache_create(slab_name, + sizeof(struct dccp_li_hist_entry), + 0, SLAB_HWCACHE_ALIGN, + NULL, NULL); + if (hist->dccplih_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_li_hist_new); + +void dccp_li_hist_delete(struct dccp_li_hist *hist) +{ + const char* name = kmem_cache_name(hist->dccplih_slab); + + kmem_cache_destroy(hist->dccplih_slab); + kfree(name); + kfree(hist); +} + +EXPORT_SYMBOL_GPL(dccp_li_hist_delete); + +void dccp_li_hist_purge(struct dccp_li_hist *hist, struct list_head *list) +{ + struct dccp_li_hist_entry *entry, *next; + + list_for_each_entry_safe(entry, next, list, dccplih_node) { + list_del_init(&entry->dccplih_node); + kmem_cache_free(hist->dccplih_slab, entry); + } +} + +EXPORT_SYMBOL_GPL(dccp_li_hist_purge); + +/* Weights used to calculate loss event rate */ +/* + * These are integers as per section 8 of RFC3448. We can then divide by 4 * + * when we use it. + */ +static const int dccp_li_hist_w[DCCP_LI_HIST_IVAL_F_LENGTH] = { + 4, 4, 4, 4, 3, 2, 1, 1, +}; + +u32 dccp_li_hist_calc_i_mean(struct list_head *list) +{ + struct dccp_li_hist_entry *li_entry, *li_next; + int i = 0; + u32 i_tot; + u32 i_tot0 = 0; + u32 i_tot1 = 0; + u32 w_tot = 0; + + list_for_each_entry_safe(li_entry, li_next, list, dccplih_node) { + if (i < DCCP_LI_HIST_IVAL_F_LENGTH) { + i_tot0 += li_entry->dccplih_interval * dccp_li_hist_w[i]; + w_tot += dccp_li_hist_w[i]; + } + + if (i != 0) + i_tot1 += li_entry->dccplih_interval * dccp_li_hist_w[i - 1]; + + if (++i > DCCP_LI_HIST_IVAL_F_LENGTH) + break; + } + + if (i != DCCP_LI_HIST_IVAL_F_LENGTH) + return 0; + + i_tot = max(i_tot0, i_tot1); + + /* FIXME: Why do we do this? -Ian McDonald */ + if (i_tot * 4 < w_tot) + i_tot = w_tot * 4; + + return i_tot * 4 / w_tot; +} + +EXPORT_SYMBOL_GPL(dccp_li_hist_calc_i_mean); + +struct dccp_li_hist_entry *dccp_li_hist_interval_new(struct dccp_li_hist *hist, + struct list_head *list, + const u64 seq_loss, + const u8 win_loss) +{ + struct dccp_li_hist_entry *tail = NULL, *entry; + int i; + + for (i = 0; i <= DCCP_LI_HIST_IVAL_F_LENGTH; ++i) { + entry = dccp_li_hist_entry_new(hist, SLAB_ATOMIC); + if (entry == NULL) { + dccp_li_hist_purge(hist, list); + return NULL; + } + if (tail == NULL) + tail = entry; + list_add(&entry->dccplih_node, list); + } + + entry->dccplih_seqno = seq_loss; + entry->dccplih_win_count = win_loss; + return tail; +} + +EXPORT_SYMBOL_GPL(dccp_li_hist_interval_new); diff --git a/net/dccp/ccids/lib/loss_interval.h b/net/dccp/ccids/lib/loss_interval.h new file mode 100644 index 0000000..13ad47b --- /dev/null +++ b/net/dccp/ccids/lib/loss_interval.h @@ -0,0 +1,61 @@ +#ifndef _DCCP_LI_HIST_ +#define _DCCP_LI_HIST_ +/* + * net/dccp/ccids/lib/loss_interval.h + * + * Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand. + * Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz> + * 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. + */ + +#include <linux/config.h> +#include <linux/list.h> +#include <linux/slab.h> +#include <linux/time.h> + +#define DCCP_LI_HIST_IVAL_F_LENGTH 8 + +struct dccp_li_hist { + kmem_cache_t *dccplih_slab; +}; + +extern struct dccp_li_hist *dccp_li_hist_new(const char *name); +extern void dccp_li_hist_delete(struct dccp_li_hist *hist); + +struct dccp_li_hist_entry { + struct list_head dccplih_node; + u64 dccplih_seqno:48, + dccplih_win_count:4; + u32 dccplih_interval; +}; + +static inline struct dccp_li_hist_entry * + dccp_li_hist_entry_new(struct dccp_li_hist *hist, + const unsigned int __nocast prio) +{ + return kmem_cache_alloc(hist->dccplih_slab, prio); +} + +static inline void dccp_li_hist_entry_delete(struct dccp_li_hist *hist, + struct dccp_li_hist_entry *entry) +{ + if (entry != NULL) + kmem_cache_free(hist->dccplih_slab, entry); +} + +extern void dccp_li_hist_purge(struct dccp_li_hist *hist, + struct list_head *list); + +extern u32 dccp_li_hist_calc_i_mean(struct list_head *list); + +extern struct dccp_li_hist_entry * + dccp_li_hist_interval_new(struct dccp_li_hist *hist, + struct list_head *list, + const u64 seq_loss, + const u8 win_loss); +#endif /* _DCCP_LI_HIST_ */ diff --git a/net/dccp/ccids/lib/packet_history.c b/net/dccp/ccids/lib/packet_history.c new file mode 100644 index 0000000..d3f9d20 --- /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"); diff --git a/net/dccp/ccids/lib/packet_history.h b/net/dccp/ccids/lib/packet_history.h new file mode 100644 index 0000000..fb90a91 --- /dev/null +++ b/net/dccp/ccids/lib/packet_history.h @@ -0,0 +1,199 @@ +/* + * 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. + */ + +#ifndef _DCCP_PKT_HIST_ +#define _DCCP_PKT_HIST_ + +#include <linux/config.h> +#include <linux/list.h> +#include <linux/slab.h> +#include <linux/time.h> + +#include "../../dccp.h" + +/* Number of later packets received before one is considered lost */ +#define TFRC_RECV_NUM_LATE_LOSS 3 + +#define TFRC_WIN_COUNT_PER_RTT 4 +#define TFRC_WIN_COUNT_LIMIT 16 + +struct dccp_tx_hist_entry { + struct list_head dccphtx_node; + u64 dccphtx_seqno:48, + dccphtx_ccval:4, + dccphtx_sent:1; + u32 dccphtx_rtt; + struct timeval dccphtx_tstamp; +}; + +struct dccp_rx_hist_entry { + struct list_head dccphrx_node; + u64 dccphrx_seqno:48, + dccphrx_ccval:4, + dccphrx_type:4; + u32 dccphrx_ndp; /* In fact it is from 8 to 24 bits */ + struct timeval dccphrx_tstamp; +}; + +struct dccp_tx_hist { + kmem_cache_t *dccptxh_slab; +}; + +extern struct dccp_tx_hist *dccp_tx_hist_new(const char *name); +extern void dccp_tx_hist_delete(struct dccp_tx_hist *hist); + +struct dccp_rx_hist { + kmem_cache_t *dccprxh_slab; +}; + +extern struct dccp_rx_hist *dccp_rx_hist_new(const char *name); +extern void dccp_rx_hist_delete(struct dccp_rx_hist *hist); +extern struct dccp_rx_hist_entry * + dccp_rx_hist_find_data_packet(const struct list_head *list); + +static inline struct dccp_tx_hist_entry * + dccp_tx_hist_entry_new(struct dccp_tx_hist *hist, + const unsigned int __nocast prio) +{ + struct dccp_tx_hist_entry *entry = kmem_cache_alloc(hist->dccptxh_slab, + prio); + + if (entry != NULL) + entry->dccphtx_sent = 0; + + return entry; +} + +static inline void dccp_tx_hist_entry_delete(struct dccp_tx_hist *hist, + struct dccp_tx_hist_entry *entry) +{ + if (entry != NULL) + kmem_cache_free(hist->dccptxh_slab, entry); +} + +extern struct dccp_tx_hist_entry * + dccp_tx_hist_find_entry(const struct list_head *list, + const u64 seq); + +static inline void dccp_tx_hist_add_entry(struct list_head *list, + struct dccp_tx_hist_entry *entry) +{ + list_add(&entry->dccphtx_node, list); +} + +extern void dccp_tx_hist_purge_older(struct dccp_tx_hist *hist, + struct list_head *list, + struct dccp_tx_hist_entry *next); + +extern void dccp_tx_hist_purge(struct dccp_tx_hist *hist, + struct list_head *list); + +static inline struct dccp_tx_hist_entry * + dccp_tx_hist_head(struct list_head *list) +{ + struct dccp_tx_hist_entry *head = NULL; + + if (!list_empty(list)) + head = list_entry(list->next, struct dccp_tx_hist_entry, + dccphtx_node); + return head; +} + +static inline struct dccp_rx_hist_entry * + dccp_rx_hist_entry_new(struct dccp_rx_hist *hist, + const u32 ndp, + const struct sk_buff *skb, + const unsigned int __nocast prio) +{ + struct dccp_rx_hist_entry *entry = kmem_cache_alloc(hist->dccprxh_slab, + prio); + + if (entry != NULL) { + const struct dccp_hdr *dh = dccp_hdr(skb); + + entry->dccphrx_seqno = DCCP_SKB_CB(skb)->dccpd_seq; + entry->dccphrx_ccval = dh->dccph_ccval; + entry->dccphrx_type = dh->dccph_type; + entry->dccphrx_ndp = ndp; + do_gettimeofday(&(entry->dccphrx_tstamp)); + } + + return entry; +} + +static inline void dccp_rx_hist_entry_delete(struct dccp_rx_hist *hist, + struct dccp_rx_hist_entry *entry) +{ + if (entry != NULL) + kmem_cache_free(hist->dccprxh_slab, entry); +} + +extern void dccp_rx_hist_purge(struct dccp_rx_hist *hist, + struct list_head *list); + +static inline void dccp_rx_hist_add_entry(struct list_head *list, + struct dccp_rx_hist_entry *entry) +{ + list_add(&entry->dccphrx_node, list); +} + +static inline struct dccp_rx_hist_entry * + dccp_rx_hist_head(struct list_head *list) +{ + struct dccp_rx_hist_entry *head = NULL; + + if (!list_empty(list)) + head = list_entry(list->next, struct dccp_rx_hist_entry, + dccphrx_node); + return head; +} + +static inline int + dccp_rx_hist_entry_data_packet(const struct dccp_rx_hist_entry *entry) +{ + return entry->dccphrx_type == DCCP_PKT_DATA || + entry->dccphrx_type == DCCP_PKT_DATAACK; +} + +extern 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); + +extern u64 dccp_rx_hist_detect_loss(struct list_head *rx_list, + struct list_head *li_list, u8 *win_loss); + +#endif /* _DCCP_PKT_HIST_ */ diff --git a/net/dccp/ccids/lib/tfrc.h b/net/dccp/ccids/lib/tfrc.h new file mode 100644 index 0000000..130c4c4 --- /dev/null +++ b/net/dccp/ccids/lib/tfrc.h @@ -0,0 +1,22 @@ +#ifndef _TFRC_H_ +#define _TFRC_H_ +/* + * net/dccp/ccids/lib/tfrc.h + * + * Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand. + * Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz> + * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br> + * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon + * + * 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. + */ + +#include <linux/types.h> + +extern u32 tfrc_calc_x(u16 s, u32 R, u32 p); +extern u32 tfrc_calc_x_reverse_lookup(u32 fvalue); + +#endif /* _TFRC_H_ */ diff --git a/net/dccp/ccids/lib/tfrc_equation.c b/net/dccp/ccids/lib/tfrc_equation.c new file mode 100644 index 0000000..d2b5933 --- /dev/null +++ b/net/dccp/ccids/lib/tfrc_equation.c @@ -0,0 +1,644 @@ +/* + * net/dccp/ccids/lib/tfrc_equation.c + * + * Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand. + * Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz> + * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br> + * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon + * + * 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. + */ + +#include <linux/config.h> +#include <linux/module.h> + +#include <asm/bug.h> +#include <asm/div64.h> + +#include "tfrc.h" + +#define TFRC_CALC_X_ARRSIZE 500 + +#define TFRC_CALC_X_SPLIT 50000 +/* equivalent to 0.05 */ + +static const u32 tfrc_calc_x_lookup[TFRC_CALC_X_ARRSIZE][2] = { + { 37172, 8172 }, + { 53499, 11567 }, + { 66664, 14180 }, + { 78298, 16388 }, + { 89021, 18339 }, + { 99147, 20108 }, + { 108858, 21738 }, + { 118273, 23260 }, + { 127474, 24693 }, + { 136520, 26052 }, + { 145456, 27348 }, + { 154316, 28589 }, + { 163130, 29783 }, + { 171919, 30935 }, + { 180704, 32049 }, + { 189502, 33130 }, + { 198328, 34180 }, + { 207194, 35202 }, + { 216114, 36198 }, + { 225097, 37172 }, + { 234153, 38123 }, + { 243294, 39055 }, + { 252527, 39968 }, + { 261861, 40864 }, + { 271305, 41743 }, + { 280866, 42607 }, + { 290553, 43457 }, + { 300372, 44293 }, + { 310333, 45117 }, + { 320441, 45929 }, + { 330705, 46729 }, + { 341131, 47518 }, + { 351728, 48297 }, + { 362501, 49066 }, + { 373460, 49826 }, + { 384609, 50577 }, + { 395958, 51320 }, + { 407513, 52054 }, + { 419281, 52780 }, + { 431270, 53499 }, + { 443487, 54211 }, + { 455940, 54916 }, + { 468635, 55614 }, + { 481581, 56306 }, + { 494785, 56991 }, + { 508254, 57671 }, + { 521996, 58345 }, + { 536019, 59014 }, + { 550331, 59677 }, + { 564939, 60335 }, + { 579851, 60988 }, + { 595075, 61636 }, + { 610619, 62279 }, + { 626491, 62918 }, + { 642700, 63553 }, + { 659253, 64183 }, + { 676158, 64809 }, + { 693424, 65431 }, + { 711060, 66050 }, + { 729073, 66664 }, + { 747472, 67275 }, + { 766266, 67882 }, + { 785464, 68486 }, + { 805073, 69087 }, + { 825103, 69684 }, + { 845562, 70278 }, + { 866460, 70868 }, + { 887805, 71456 }, + { 909606, 72041 }, + { 931873, 72623 }, + { 954614, 73202 }, + { 977839, 73778 }, + { 1001557, 74352 }, + { 1025777, 74923 }, + { 1050508, 75492 }, + { 1075761, 76058 }, + { 1101544, 76621 }, + { 1127867, 77183 }, + { 1154739, 77741 }, + { 1182172, 78298 }, + { 1210173, 78852 }, + { 1238753, 79405 }, + { 1267922, 79955 }, + { 1297689, 80503 }, + { 1328066, 81049 }, + { 1359060, 81593 }, + { 1390684, 82135 }, + { 1422947, 82675 }, + { 1455859, 83213 }, + { 1489430, 83750 }, + { 1523671, 84284 }, + { 1558593, 84817 }, + { 1594205, 85348 }, + { 1630518, 85878 }, + { 1667543, 86406 }, + { 1705290, 86932 }, + { 1743770, 87457 }, + { 1782994, 87980 }, + { 1822973, 88501 }, + { 1863717, 89021 }, + { 1905237, 89540 }, + { 1947545, 90057 }, + { 1990650, 90573 }, + { 2034566, 91087 }, + { 2079301, 91600 }, + { 2124869, 92111 }, + { 2171279, 92622 }, + { 2218543, 93131 }, + { 2266673, 93639 }, + { 2315680, 94145 }, + { 2365575, 94650 }, + { 2416371, 95154 }, + { 2468077, 95657 }, + { 2520707, 96159 }, + { 2574271, 96660 }, + { 2628782, 97159 }, + { 2684250, 97658 }, + { 2740689, 98155 }, + { 2798110, 98651 }, + { 2856524, 99147 }, + { 2915944, 99641 }, + { 2976382, 100134 }, + { 3037850, 100626 }, + { 3100360, 101117 }, + { 3163924, 101608 }, + { 3228554, 102097 }, + { 3294263, 102586 }, + { 3361063, 103073 }, + { 3428966, 103560 }, + { 3497984, 104045 }, + { 3568131, 104530 }, + { 3639419, 105014 }, + { 3711860, 105498 }, + { 3785467, 105980 }, + { 3860253, 106462 }, + { 3936229, 106942 }, + { 4013410, 107422 }, + { 4091808, 107902 }, + { 4171435, 108380 }, + { 4252306, 108858 }, + { 4334431, 109335 }, + { 4417825, 109811 }, + { 4502501, 110287 }, + { 4588472, 110762 }, + { 4675750, 111236 }, + { 4764349, 111709 }, + { 4854283, 112182 }, + { 4945564, 112654 }, + { 5038206, 113126 }, + { 5132223, 113597 }, + { 5227627, 114067 }, + { 5324432, 114537 }, + { 5422652, 115006 }, + { 5522299, 115474 }, + { 5623389, 115942 }, + { 5725934, 116409 }, + { 5829948, 116876 }, + { 5935446, 117342 }, + { 6042439, 117808 }, + { 6150943, 118273 }, + { 6260972, 118738 }, + { 6372538, 119202 }, + { 6485657, 119665 }, + { 6600342, 120128 }, + { 6716607, 120591 }, + { 6834467, 121053 }, + { 6953935, 121514 }, + { 7075025, 121976 }, + { 7197752, 122436 }, + { 7322131, 122896 }, + { 7448175, 123356 }, + { 7575898, 123815 }, + { 7705316, 124274 }, + { 7836442, 124733 }, + { 7969291, 125191 }, + { 8103877, 125648 }, + { 8240216, 126105 }, + { 8378321, 126562 }, + { 8518208, 127018 }, + { 8659890, 127474 }, + { 8803384, 127930 }, + { 8948702, 128385 }, + { 9095861, 128840 }, + { 9244875, 129294 }, + { 9395760, 129748 }, + { 9548529, 130202 }, + { 9703198, 130655 }, + { 9859782, 131108 }, + { 10018296, 131561 }, + { 10178755, 132014 }, + { 10341174, 132466 }, + { 10505569, 132917 }, + { 10671954, 133369 }, + { 10840345, 133820 }, + { 11010757, 134271 }, + { 11183206, 134721 }, + { 11357706, 135171 }, + { 11534274, 135621 }, + { 11712924, 136071 }, + { 11893673, 136520 }, + { 12076536, 136969 }, + { 12261527, 137418 }, + { 12448664, 137867 }, + { 12637961, 138315 }, + { 12829435, 138763 }, + { 13023101, 139211 }, + { 13218974, 139658 }, + { 13417071, 140106 }, + { 13617407, 140553 }, + { 13819999, 140999 }, + { 14024862, 141446 }, + { 14232012, 141892 }, + { 14441465, 142339 }, + { 14653238, 142785 }, + { 14867346, 143230 }, + { 15083805, 143676 }, + { 15302632, 144121 }, + { 15523842, 144566 }, + { 15747453, 145011 }, + { 15973479, 145456 }, + { 16201939, 145900 }, + { 16432847, 146345 }, + { 16666221, 146789 }, + { 16902076, 147233 }, + { 17140429, 147677 }, + { 17381297, 148121 }, + { 17624696, 148564 }, + { 17870643, 149007 }, + { 18119154, 149451 }, + { 18370247, 149894 }, + { 18623936, 150336 }, + { 18880241, 150779 }, + { 19139176, 151222 }, + { 19400759, 151664 }, + { 19665007, 152107 }, + { 19931936, 152549 }, + { 20201564, 152991 }, + { 20473907, 153433 }, + { 20748982, 153875 }, + { 21026807, 154316 }, + { 21307399, 154758 }, + { 21590773, 155199 }, + { 21876949, 155641 }, + { 22165941, 156082 }, + { 22457769, 156523 }, + { 22752449, 156964 }, + { 23049999, 157405 }, + { 23350435, 157846 }, + { 23653774, 158287 }, + { 23960036, 158727 }, + { 24269236, 159168 }, + { 24581392, 159608 }, + { 24896521, 160049 }, + { 25214642, 160489 }, + { 25535772, 160929 }, + { 25859927, 161370 }, + { 26187127, 161810 }, + { 26517388, 162250 }, + { 26850728, 162690 }, + { 27187165, 163130 }, + { 27526716, 163569 }, + { 27869400, 164009 }, + { 28215234, 164449 }, + { 28564236, 164889 }, + { 28916423, 165328 }, + { 29271815, 165768 }, + { 29630428, 166208 }, + { 29992281, 166647 }, + { 30357392, 167087 }, + { 30725779, 167526 }, + { 31097459, 167965 }, + { 31472452, 168405 }, + { 31850774, 168844 }, + { 32232445, 169283 }, + { 32617482, 169723 }, + { 33005904, 170162 }, + { 33397730, 170601 }, + { 33792976, 171041 }, + { 34191663, 171480 }, + { 34593807, 171919 }, + { 34999428, 172358 }, + { 35408544, 172797 }, + { 35821174, 173237 }, + { 36237335, 173676 }, + { 36657047, 174115 }, + { 37080329, 174554 }, + { 37507197, 174993 }, + { 37937673, 175433 }, + { 38371773, 175872 }, + { 38809517, 176311 }, + { 39250924, 176750 }, + { 39696012, 177190 }, + { 40144800, 177629 }, + { 40597308, 178068 }, + { 41053553, 178507 }, + { 41513554, 178947 }, + { 41977332, 179386 }, + { 42444904, 179825 }, + { 42916290, 180265 }, + { 43391509, 180704 }, + { 43870579, 181144 }, + { 44353520, 181583 }, + { 44840352, 182023 }, + { 45331092, 182462 }, + { 45825761, 182902 }, + { 46324378, 183342 }, + { 46826961, 183781 }, + { 47333531, 184221 }, + { 47844106, 184661 }, + { 48358706, 185101 }, + { 48877350, 185541 }, + { 49400058, 185981 }, + { 49926849, 186421 }, + { 50457743, 186861 }, + { 50992759, 187301 }, + { 51531916, 187741 }, + { 52075235, 188181 }, + { 52622735, 188622 }, + { 53174435, 189062 }, + { 53730355, 189502 }, + { 54290515, 189943 }, + { 54854935, 190383 }, + { 55423634, 190824 }, + { 55996633, 191265 }, + { 56573950, 191706 }, + { 57155606, 192146 }, + { 57741621, 192587 }, + { 58332014, 193028 }, + { 58926806, 193470 }, + { 59526017, 193911 }, + { 60129666, 194352 }, + { 60737774, 194793 }, + { 61350361, 195235 }, + { 61967446, 195677 }, + { 62589050, 196118 }, + { 63215194, 196560 }, + { 63845897, 197002 }, + { 64481179, 197444 }, + { 65121061, 197886 }, + { 65765563, 198328 }, + { 66414705, 198770 }, + { 67068508, 199213 }, + { 67726992, 199655 }, + { 68390177, 200098 }, + { 69058085, 200540 }, + { 69730735, 200983 }, + { 70408147, 201426 }, + { 71090343, 201869 }, + { 71777343, 202312 }, + { 72469168, 202755 }, + { 73165837, 203199 }, + { 73867373, 203642 }, + { 74573795, 204086 }, + { 75285124, 204529 }, + { 76001380, 204973 }, + { 76722586, 205417 }, + { 77448761, 205861 }, + { 78179926, 206306 }, + { 78916102, 206750 }, + { 79657310, 207194 }, + { 80403571, 207639 }, + { 81154906, 208084 }, + { 81911335, 208529 }, + { 82672880, 208974 }, + { 83439562, 209419 }, + { 84211402, 209864 }, + { 84988421, 210309 }, + { 85770640, 210755 }, + { 86558080, 211201 }, + { 87350762, 211647 }, + { 88148708, 212093 }, + { 88951938, 212539 }, + { 89760475, 212985 }, + { 90574339, 213432 }, + { 91393551, 213878 }, + { 92218133, 214325 }, + { 93048107, 214772 }, + { 93883493, 215219 }, + { 94724314, 215666 }, + { 95570590, 216114 }, + { 96422343, 216561 }, + { 97279594, 217009 }, + { 98142366, 217457 }, + { 99010679, 217905 }, + { 99884556, 218353 }, + { 100764018, 218801 }, + { 101649086, 219250 }, + { 102539782, 219698 }, + { 103436128, 220147 }, + { 104338146, 220596 }, + { 105245857, 221046 }, + { 106159284, 221495 }, + { 107078448, 221945 }, + { 108003370, 222394 }, + { 108934074, 222844 }, + { 109870580, 223294 }, + { 110812910, 223745 }, + { 111761087, 224195 }, + { 112715133, 224646 }, + { 113675069, 225097 }, + { 114640918, 225548 }, + { 115612702, 225999 }, + { 116590442, 226450 }, + { 117574162, 226902 }, + { 118563882, 227353 }, + { 119559626, 227805 }, + { 120561415, 228258 }, + { 121569272, 228710 }, + { 122583219, 229162 }, + { 123603278, 229615 }, + { 124629471, 230068 }, + { 125661822, 230521 }, + { 126700352, 230974 }, + { 127745083, 231428 }, + { 128796039, 231882 }, + { 129853241, 232336 }, + { 130916713, 232790 }, + { 131986475, 233244 }, + { 133062553, 233699 }, + { 134144966, 234153 }, + { 135233739, 234608 }, + { 136328894, 235064 }, + { 137430453, 235519 }, + { 138538440, 235975 }, + { 139652876, 236430 }, + { 140773786, 236886 }, + { 141901190, 237343 }, + { 143035113, 237799 }, + { 144175576, 238256 }, + { 145322604, 238713 }, + { 146476218, 239170 }, + { 147636442, 239627 }, + { 148803298, 240085 }, + { 149976809, 240542 }, + { 151156999, 241000 }, + { 152343890, 241459 }, + { 153537506, 241917 }, + { 154737869, 242376 }, + { 155945002, 242835 }, + { 157158929, 243294 }, + { 158379673, 243753 }, + { 159607257, 244213 }, + { 160841704, 244673 }, + { 162083037, 245133 }, + { 163331279, 245593 }, + { 164586455, 246054 }, + { 165848586, 246514 }, + { 167117696, 246975 }, + { 168393810, 247437 }, + { 169676949, 247898 }, + { 170967138, 248360 }, + { 172264399, 248822 }, + { 173568757, 249284 }, + { 174880235, 249747 }, + { 176198856, 250209 }, + { 177524643, 250672 }, + { 178857621, 251136 }, + { 180197813, 251599 }, + { 181545242, 252063 }, + { 182899933, 252527 }, + { 184261908, 252991 }, + { 185631191, 253456 }, + { 187007807, 253920 }, + { 188391778, 254385 }, + { 189783129, 254851 }, + { 191181884, 255316 }, + { 192588065, 255782 }, + { 194001698, 256248 }, + { 195422805, 256714 }, + { 196851411, 257181 }, + { 198287540, 257648 }, + { 199731215, 258115 }, + { 201182461, 258582 }, + { 202641302, 259050 }, + { 204107760, 259518 }, + { 205581862, 259986 }, + { 207063630, 260454 }, + { 208553088, 260923 }, + { 210050262, 261392 }, + { 211555174, 261861 }, + { 213067849, 262331 }, + { 214588312, 262800 }, + { 216116586, 263270 }, + { 217652696, 263741 }, + { 219196666, 264211 }, + { 220748520, 264682 }, + { 222308282, 265153 }, + { 223875978, 265625 }, + { 225451630, 266097 }, + { 227035265, 266569 }, + { 228626905, 267041 }, + { 230226576, 267514 }, + { 231834302, 267986 }, + { 233450107, 268460 }, + { 235074016, 268933 }, + { 236706054, 269407 }, + { 238346244, 269881 }, + { 239994613, 270355 }, + { 241651183, 270830 }, + { 243315981, 271305 } +}; + +/* Calculate the send rate as per section 3.1 of RFC3448 + +Returns send rate in bytes per second + +Integer maths and lookups are used as not allowed floating point in kernel + +The function for Xcalc as per section 3.1 of RFC3448 is: + +X = s + ------------------------------------------------------------- + R*sqrt(2*b*p/3) + (t_RTO * (3*sqrt(3*b*p/8) * p * (1+32*p^2))) + +where +X is the trasmit rate in bytes/second +s is the packet size in bytes +R is the round trip time in seconds +p is the loss event rate, between 0 and 1.0, of the number of loss events + as a fraction of the number of packets transmitted +t_RTO is the TCP retransmission timeout value in seconds +b is the number of packets acknowledged by a single TCP acknowledgement + +we can assume that b = 1 and t_RTO is 4 * R. With this the equation becomes: + +X = s + ----------------------------------------------------------------------- + R * sqrt(2 * p / 3) + (12 * R * (sqrt(3 * p / 8) * p * (1 + 32 * p^2))) + + +which we can break down into: + +X = s + -------- + R * f(p) + +where f(p) = sqrt(2 * p / 3) + (12 * sqrt(3 * p / 8) * p * (1 + 32 * p * p)) + +Function parameters: +s - bytes +R - RTT in usecs +p - loss rate (decimal fraction multiplied by 1,000,000) + +Returns Xcalc in bytes per second + +DON'T alter this code unless you run test cases against it as the code +has been manipulated to stop underflow/overlow. + +*/ +u32 tfrc_calc_x(u16 s, u32 R, u32 p) +{ + int index; + u32 f; + u64 tmp1, tmp2; + + if (p < TFRC_CALC_X_SPLIT) + index = (p / (TFRC_CALC_X_SPLIT / TFRC_CALC_X_ARRSIZE)) - 1; + else + index = (p / (1000000 / TFRC_CALC_X_ARRSIZE)) - 1; + + if (index < 0) + /* p should be 0 unless there is a bug in my code */ + index = 0; + + if (R == 0) + R = 1; /* RTT can't be zero or else divide by zero */ + + BUG_ON(index >= TFRC_CALC_X_ARRSIZE); + + if (p >= TFRC_CALC_X_SPLIT) + f = tfrc_calc_x_lookup[index][0]; + else + f = tfrc_calc_x_lookup[index][1]; + + tmp1 = ((u64)s * 100000000); + tmp2 = ((u64)R * (u64)f); + do_div(tmp2, 10000); + do_div(tmp1, tmp2); + /* Don't alter above math unless you test due to overflow on 32 bit */ + + return (u32)tmp1; +} + +EXPORT_SYMBOL_GPL(tfrc_calc_x); + +/* + * args: fvalue - function value to match + * returns: p closest to that value + * + * both fvalue and p are multiplied by 1,000,000 to use ints + */ +u32 tfrc_calc_x_reverse_lookup(u32 fvalue) +{ + int ctr = 0; + int small; + + if (fvalue < tfrc_calc_x_lookup[0][1]) + return 0; + + if (fvalue <= tfrc_calc_x_lookup[TFRC_CALC_X_ARRSIZE - 1][1]) + small = 1; + else if (fvalue > tfrc_calc_x_lookup[TFRC_CALC_X_ARRSIZE - 1][0]) + return 1000000; + else + small = 0; + + while (fvalue > tfrc_calc_x_lookup[ctr][small]) + ctr++; + + if (small) + return TFRC_CALC_X_SPLIT * ctr / TFRC_CALC_X_ARRSIZE; + else + return 1000000 * ctr / TFRC_CALC_X_ARRSIZE; +} + +EXPORT_SYMBOL_GPL(tfrc_calc_x_reverse_lookup); |