linux/net/mac80211/rc80211_minstrel_debugfs.c
Karl Beldan 11b2357d5d mac80211: minstrels: fix buffer overflow in HT debugfs rc_stats
ATM an HT rc_stats line is 106 chars.
Times 8(MCS_GROUP_RATES)*3(SS)*2(GI)*2(BW) + CCK(4), i.e. x100, this is
well above the current 8192 - sizeof(*ms) currently allocated.

Fix this by squeezing the output as follows (not that we're short on
memory but this also improves readability and range, the new format adds
one more digit to *ok/*cum and ok/cum):

- Before (HT) (106 ch):
type           rate     throughput  ewma prob   this prob  retry   this succ/attempt   success    attempts
CCK/LP          5.5M           0.0        0.0         0.0      0              0(  0)         0           0
HT20/LGI ABCDP MCS0            0.0        0.0         0.0      1              0(  0)         0           0
- After (75 ch):
type           rate     tpt eprob *prob ret  *ok(*cum)        ok(      cum)
CCK/LP          5.5M    0.0   0.0   0.0   0    0(   0)         0(        0)
HT20/LGI ABCDP MCS0     0.0   0.0   0.0   1    0(   0)         0(        0)

- Align non-HT format Before (non-HT) (83 ch):
rate      throughput  ewma prob  this prob  this succ/attempt   success    attempts
ABCDP  6         0.0        0.0        0.0             0(  0)         0           0
      54         0.0        0.0        0.0             0(  0)         0           0
- After (61 ch):
rate          tpt eprob *prob  *ok(*cum)        ok(      cum)
ABCDP  1      0.0   0.0   0.0    0(   0)         0(        0)
      54      0.0   0.0   0.0    0(   0)         0(        0)

*This also adds dynamic checks for overflow, lowers the size of the
non-HT request (allowing > 30 entries) and replaces the buddy-rounded
allocations (s/sizeof(*ms) + 8192/8192).

Signed-off-by: Karl Beldan <karl.beldan@rivierawaves.com>
Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2014-10-20 16:37:01 +02:00

150 lines
4.9 KiB
C

/*
* Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Based on minstrel.c:
* Copyright (C) 2005-2007 Derek Smithies <derek@indranet.co.nz>
* Sponsored by Indranet Technologies Ltd
*
* Based on sample.c:
* Copyright (c) 2005 John Bicket
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
* redistribution must be conditioned upon including a substantially
* similar Disclaimer requirement for further binary redistribution.
* 3. Neither the names of the above-listed copyright holders nor the names
* of any contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* NO WARRANTY
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
* OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
* IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGES.
*/
#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/skbuff.h>
#include <linux/debugfs.h>
#include <linux/ieee80211.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <net/mac80211.h>
#include "rc80211_minstrel.h"
int
minstrel_stats_open(struct inode *inode, struct file *file)
{
struct minstrel_sta_info *mi = inode->i_private;
struct minstrel_debugfs_info *ms;
unsigned int i, tp, prob, eprob;
char *p;
ms = kmalloc(2048, GFP_KERNEL);
if (!ms)
return -ENOMEM;
file->private_data = ms;
p = ms->buf;
p += sprintf(p, "rate tpt eprob *prob"
" *ok(*cum) ok( cum)\n");
for (i = 0; i < mi->n_rates; i++) {
struct minstrel_rate *mr = &mi->r[i];
struct minstrel_rate_stats *mrs = &mi->r[i].stats;
*(p++) = (i == mi->max_tp_rate[0]) ? 'A' : ' ';
*(p++) = (i == mi->max_tp_rate[1]) ? 'B' : ' ';
*(p++) = (i == mi->max_tp_rate[2]) ? 'C' : ' ';
*(p++) = (i == mi->max_tp_rate[3]) ? 'D' : ' ';
*(p++) = (i == mi->max_prob_rate) ? 'P' : ' ';
p += sprintf(p, "%3u%s", mr->bitrate / 2,
(mr->bitrate & 1 ? ".5" : " "));
tp = MINSTREL_TRUNC(mrs->cur_tp / 10);
prob = MINSTREL_TRUNC(mrs->cur_prob * 1000);
eprob = MINSTREL_TRUNC(mrs->probability * 1000);
p += sprintf(p, " %4u.%1u %3u.%1u %3u.%1u"
" %4u(%4u) %9llu(%9llu)\n",
tp / 10, tp % 10,
eprob / 10, eprob % 10,
prob / 10, prob % 10,
mrs->last_success,
mrs->last_attempts,
(unsigned long long)mrs->succ_hist,
(unsigned long long)mrs->att_hist);
}
p += sprintf(p, "\nTotal packet count:: ideal %d "
"lookaround %d\n\n",
mi->total_packets - mi->sample_packets,
mi->sample_packets);
ms->len = p - ms->buf;
WARN_ON(ms->len + sizeof(*ms) > 2048);
return 0;
}
ssize_t
minstrel_stats_read(struct file *file, char __user *buf, size_t len, loff_t *ppos)
{
struct minstrel_debugfs_info *ms;
ms = file->private_data;
return simple_read_from_buffer(buf, len, ppos, ms->buf, ms->len);
}
int
minstrel_stats_release(struct inode *inode, struct file *file)
{
kfree(file->private_data);
return 0;
}
static const struct file_operations minstrel_stat_fops = {
.owner = THIS_MODULE,
.open = minstrel_stats_open,
.read = minstrel_stats_read,
.release = minstrel_stats_release,
.llseek = default_llseek,
};
void
minstrel_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir)
{
struct minstrel_sta_info *mi = priv_sta;
mi->dbg_stats = debugfs_create_file("rc_stats", S_IRUGO, dir, mi,
&minstrel_stat_fops);
}
void
minstrel_remove_sta_debugfs(void *priv, void *priv_sta)
{
struct minstrel_sta_info *mi = priv_sta;
debugfs_remove(mi->dbg_stats);
}