1/*
2 * proc.c - procfs support for Protocol family CAN core module
3 *
4 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of Volkswagen nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * Alternatively, provided that this notice is retained in full, this
20 * software may be distributed under the terms of the GNU General
21 * Public License ("GPL") version 2, in which case the provisions of the
22 * GPL apply INSTEAD OF those given above.
23 *
24 * The provided data structures and external interfaces from this code
25 * are not restricted to be used by modules with a GPL compatible license.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
38 * DAMAGE.
39 *
40 */
41
42#include <linux/module.h>
43#include <linux/proc_fs.h>
44#include <linux/list.h>
45#include <linux/rcupdate.h>
46#include <linux/if_arp.h>
47#include <linux/can/core.h>
48
49#include "af_can.h"
50
51/*
52 * proc filenames for the PF_CAN core
53 */
54
55#define CAN_PROC_VERSION     "version"
56#define CAN_PROC_STATS       "stats"
57#define CAN_PROC_RESET_STATS "reset_stats"
58#define CAN_PROC_RCVLIST_ALL "rcvlist_all"
59#define CAN_PROC_RCVLIST_FIL "rcvlist_fil"
60#define CAN_PROC_RCVLIST_INV "rcvlist_inv"
61#define CAN_PROC_RCVLIST_SFF "rcvlist_sff"
62#define CAN_PROC_RCVLIST_EFF "rcvlist_eff"
63#define CAN_PROC_RCVLIST_ERR "rcvlist_err"
64
65static struct proc_dir_entry *can_dir;
66static struct proc_dir_entry *pde_version;
67static struct proc_dir_entry *pde_stats;
68static struct proc_dir_entry *pde_reset_stats;
69static struct proc_dir_entry *pde_rcvlist_all;
70static struct proc_dir_entry *pde_rcvlist_fil;
71static struct proc_dir_entry *pde_rcvlist_inv;
72static struct proc_dir_entry *pde_rcvlist_sff;
73static struct proc_dir_entry *pde_rcvlist_eff;
74static struct proc_dir_entry *pde_rcvlist_err;
75
76static int user_reset;
77
78static const char rx_list_name[][8] = {
79	[RX_ERR] = "rx_err",
80	[RX_ALL] = "rx_all",
81	[RX_FIL] = "rx_fil",
82	[RX_INV] = "rx_inv",
83};
84
85/*
86 * af_can statistics stuff
87 */
88
89static void can_init_stats(void)
90{
91	/*
92	 * This memset function is called from a timer context (when
93	 * can_stattimer is active which is the default) OR in a process
94	 * context (reading the proc_fs when can_stattimer is disabled).
95	 */
96	memset(&can_stats, 0, sizeof(can_stats));
97	can_stats.jiffies_init = jiffies;
98
99	can_pstats.stats_reset++;
100
101	if (user_reset) {
102		user_reset = 0;
103		can_pstats.user_reset++;
104	}
105}
106
107static unsigned long calc_rate(unsigned long oldjif, unsigned long newjif,
108			       unsigned long count)
109{
110	unsigned long rate;
111
112	if (oldjif == newjif)
113		return 0;
114
115	/* see can_stat_update() - this should NEVER happen! */
116	if (count > (ULONG_MAX / HZ)) {
117		printk(KERN_ERR "can: calc_rate: count exceeded! %ld\n",
118		       count);
119		return 99999999;
120	}
121
122	rate = (count * HZ) / (newjif - oldjif);
123
124	return rate;
125}
126
127void can_stat_update(unsigned long data)
128{
129	unsigned long j = jiffies; /* snapshot */
130
131	/* restart counting in timer context on user request */
132	if (user_reset)
133		can_init_stats();
134
135	/* restart counting on jiffies overflow */
136	if (j < can_stats.jiffies_init)
137		can_init_stats();
138
139	/* prevent overflow in calc_rate() */
140	if (can_stats.rx_frames > (ULONG_MAX / HZ))
141		can_init_stats();
142
143	/* prevent overflow in calc_rate() */
144	if (can_stats.tx_frames > (ULONG_MAX / HZ))
145		can_init_stats();
146
147	/* matches overflow - very improbable */
148	if (can_stats.matches > (ULONG_MAX / 100))
149		can_init_stats();
150
151	/* calc total values */
152	if (can_stats.rx_frames)
153		can_stats.total_rx_match_ratio = (can_stats.matches * 100) /
154			can_stats.rx_frames;
155
156	can_stats.total_tx_rate = calc_rate(can_stats.jiffies_init, j,
157					    can_stats.tx_frames);
158	can_stats.total_rx_rate = calc_rate(can_stats.jiffies_init, j,
159					    can_stats.rx_frames);
160
161	/* calc current values */
162	if (can_stats.rx_frames_delta)
163		can_stats.current_rx_match_ratio =
164			(can_stats.matches_delta * 100) /
165			can_stats.rx_frames_delta;
166
167	can_stats.current_tx_rate = calc_rate(0, HZ, can_stats.tx_frames_delta);
168	can_stats.current_rx_rate = calc_rate(0, HZ, can_stats.rx_frames_delta);
169
170	/* check / update maximum values */
171	if (can_stats.max_tx_rate < can_stats.current_tx_rate)
172		can_stats.max_tx_rate = can_stats.current_tx_rate;
173
174	if (can_stats.max_rx_rate < can_stats.current_rx_rate)
175		can_stats.max_rx_rate = can_stats.current_rx_rate;
176
177	if (can_stats.max_rx_match_ratio < can_stats.current_rx_match_ratio)
178		can_stats.max_rx_match_ratio = can_stats.current_rx_match_ratio;
179
180	/* clear values for 'current rate' calculation */
181	can_stats.tx_frames_delta = 0;
182	can_stats.rx_frames_delta = 0;
183	can_stats.matches_delta   = 0;
184
185	/* restart timer (one second) */
186	mod_timer(&can_stattimer, round_jiffies(jiffies + HZ));
187}
188
189/*
190 * proc read functions
191 */
192
193static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list,
194			      struct net_device *dev)
195{
196	struct receiver *r;
197
198	hlist_for_each_entry_rcu(r, rx_list, list) {
199		char *fmt = (r->can_id & CAN_EFF_FLAG)?
200			"   %-5s  %08x  %08x  %pK  %pK  %8ld  %s\n" :
201			"   %-5s     %03x    %08x  %pK  %pK  %8ld  %s\n";
202
203		seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
204				r->func, r->data, r->matches, r->ident);
205	}
206}
207
208static void can_print_recv_banner(struct seq_file *m)
209{
210	/*
211	 *                  can1.  00000000  00000000  00000000
212	 *                 .......          0  tp20
213	 */
214	seq_puts(m, "  device   can_id   can_mask  function"
215			"  userdata   matches  ident\n");
216}
217
218static int can_stats_proc_show(struct seq_file *m, void *v)
219{
220	seq_putc(m, '\n');
221	seq_printf(m, " %8ld transmitted frames (TXF)\n", can_stats.tx_frames);
222	seq_printf(m, " %8ld received frames (RXF)\n", can_stats.rx_frames);
223	seq_printf(m, " %8ld matched frames (RXMF)\n", can_stats.matches);
224
225	seq_putc(m, '\n');
226
227	if (can_stattimer.function == can_stat_update) {
228		seq_printf(m, " %8ld %% total match ratio (RXMR)\n",
229				can_stats.total_rx_match_ratio);
230
231		seq_printf(m, " %8ld frames/s total tx rate (TXR)\n",
232				can_stats.total_tx_rate);
233		seq_printf(m, " %8ld frames/s total rx rate (RXR)\n",
234				can_stats.total_rx_rate);
235
236		seq_putc(m, '\n');
237
238		seq_printf(m, " %8ld %% current match ratio (CRXMR)\n",
239				can_stats.current_rx_match_ratio);
240
241		seq_printf(m, " %8ld frames/s current tx rate (CTXR)\n",
242				can_stats.current_tx_rate);
243		seq_printf(m, " %8ld frames/s current rx rate (CRXR)\n",
244				can_stats.current_rx_rate);
245
246		seq_putc(m, '\n');
247
248		seq_printf(m, " %8ld %% max match ratio (MRXMR)\n",
249				can_stats.max_rx_match_ratio);
250
251		seq_printf(m, " %8ld frames/s max tx rate (MTXR)\n",
252				can_stats.max_tx_rate);
253		seq_printf(m, " %8ld frames/s max rx rate (MRXR)\n",
254				can_stats.max_rx_rate);
255
256		seq_putc(m, '\n');
257	}
258
259	seq_printf(m, " %8ld current receive list entries (CRCV)\n",
260			can_pstats.rcv_entries);
261	seq_printf(m, " %8ld maximum receive list entries (MRCV)\n",
262			can_pstats.rcv_entries_max);
263
264	if (can_pstats.stats_reset)
265		seq_printf(m, "\n %8ld statistic resets (STR)\n",
266				can_pstats.stats_reset);
267
268	if (can_pstats.user_reset)
269		seq_printf(m, " %8ld user statistic resets (USTR)\n",
270				can_pstats.user_reset);
271
272	seq_putc(m, '\n');
273	return 0;
274}
275
276static int can_stats_proc_open(struct inode *inode, struct file *file)
277{
278	return single_open(file, can_stats_proc_show, NULL);
279}
280
281static const struct file_operations can_stats_proc_fops = {
282	.owner		= THIS_MODULE,
283	.open		= can_stats_proc_open,
284	.read		= seq_read,
285	.llseek		= seq_lseek,
286	.release	= single_release,
287};
288
289static int can_reset_stats_proc_show(struct seq_file *m, void *v)
290{
291	user_reset = 1;
292
293	if (can_stattimer.function == can_stat_update) {
294		seq_printf(m, "Scheduled statistic reset #%ld.\n",
295				can_pstats.stats_reset + 1);
296
297	} else {
298		if (can_stats.jiffies_init != jiffies)
299			can_init_stats();
300
301		seq_printf(m, "Performed statistic reset #%ld.\n",
302				can_pstats.stats_reset);
303	}
304	return 0;
305}
306
307static int can_reset_stats_proc_open(struct inode *inode, struct file *file)
308{
309	return single_open(file, can_reset_stats_proc_show, NULL);
310}
311
312static const struct file_operations can_reset_stats_proc_fops = {
313	.owner		= THIS_MODULE,
314	.open		= can_reset_stats_proc_open,
315	.read		= seq_read,
316	.llseek		= seq_lseek,
317	.release	= single_release,
318};
319
320static int can_version_proc_show(struct seq_file *m, void *v)
321{
322	seq_printf(m, "%s\n", CAN_VERSION_STRING);
323	return 0;
324}
325
326static int can_version_proc_open(struct inode *inode, struct file *file)
327{
328	return single_open(file, can_version_proc_show, NULL);
329}
330
331static const struct file_operations can_version_proc_fops = {
332	.owner		= THIS_MODULE,
333	.open		= can_version_proc_open,
334	.read		= seq_read,
335	.llseek		= seq_lseek,
336	.release	= single_release,
337};
338
339static inline void can_rcvlist_proc_show_one(struct seq_file *m, int idx,
340					     struct net_device *dev,
341					     struct dev_rcv_lists *d)
342{
343	if (!hlist_empty(&d->rx[idx])) {
344		can_print_recv_banner(m);
345		can_print_rcvlist(m, &d->rx[idx], dev);
346	} else
347		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
348
349}
350
351static int can_rcvlist_proc_show(struct seq_file *m, void *v)
352{
353	/* double cast to prevent GCC warning */
354	int idx = (int)(long)m->private;
355	struct net_device *dev;
356	struct dev_rcv_lists *d;
357
358	seq_printf(m, "\nreceive list '%s':\n", rx_list_name[idx]);
359
360	rcu_read_lock();
361
362	/* receive list for 'all' CAN devices (dev == NULL) */
363	d = &can_rx_alldev_list;
364	can_rcvlist_proc_show_one(m, idx, NULL, d);
365
366	/* receive list for registered CAN devices */
367	for_each_netdev_rcu(&init_net, dev) {
368		if (dev->type == ARPHRD_CAN && dev->ml_priv)
369			can_rcvlist_proc_show_one(m, idx, dev, dev->ml_priv);
370	}
371
372	rcu_read_unlock();
373
374	seq_putc(m, '\n');
375	return 0;
376}
377
378static int can_rcvlist_proc_open(struct inode *inode, struct file *file)
379{
380	return single_open(file, can_rcvlist_proc_show, PDE_DATA(inode));
381}
382
383static const struct file_operations can_rcvlist_proc_fops = {
384	.owner		= THIS_MODULE,
385	.open		= can_rcvlist_proc_open,
386	.read		= seq_read,
387	.llseek		= seq_lseek,
388	.release	= single_release,
389};
390
391static inline void can_rcvlist_proc_show_array(struct seq_file *m,
392					       struct net_device *dev,
393					       struct hlist_head *rcv_array,
394					       unsigned int rcv_array_sz)
395{
396	unsigned int i;
397	int all_empty = 1;
398
399	/* check whether at least one list is non-empty */
400	for (i = 0; i < rcv_array_sz; i++)
401		if (!hlist_empty(&rcv_array[i])) {
402			all_empty = 0;
403			break;
404		}
405
406	if (!all_empty) {
407		can_print_recv_banner(m);
408		for (i = 0; i < rcv_array_sz; i++) {
409			if (!hlist_empty(&rcv_array[i]))
410				can_print_rcvlist(m, &rcv_array[i], dev);
411		}
412	} else
413		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
414}
415
416static int can_rcvlist_sff_proc_show(struct seq_file *m, void *v)
417{
418	struct net_device *dev;
419	struct dev_rcv_lists *d;
420
421	/* RX_SFF */
422	seq_puts(m, "\nreceive list 'rx_sff':\n");
423
424	rcu_read_lock();
425
426	/* sff receive list for 'all' CAN devices (dev == NULL) */
427	d = &can_rx_alldev_list;
428	can_rcvlist_proc_show_array(m, NULL, d->rx_sff, ARRAY_SIZE(d->rx_sff));
429
430	/* sff receive list for registered CAN devices */
431	for_each_netdev_rcu(&init_net, dev) {
432		if (dev->type == ARPHRD_CAN && dev->ml_priv) {
433			d = dev->ml_priv;
434			can_rcvlist_proc_show_array(m, dev, d->rx_sff,
435						    ARRAY_SIZE(d->rx_sff));
436		}
437	}
438
439	rcu_read_unlock();
440
441	seq_putc(m, '\n');
442	return 0;
443}
444
445static int can_rcvlist_sff_proc_open(struct inode *inode, struct file *file)
446{
447	return single_open(file, can_rcvlist_sff_proc_show, NULL);
448}
449
450static const struct file_operations can_rcvlist_sff_proc_fops = {
451	.owner		= THIS_MODULE,
452	.open		= can_rcvlist_sff_proc_open,
453	.read		= seq_read,
454	.llseek		= seq_lseek,
455	.release	= single_release,
456};
457
458
459static int can_rcvlist_eff_proc_show(struct seq_file *m, void *v)
460{
461	struct net_device *dev;
462	struct dev_rcv_lists *d;
463
464	/* RX_EFF */
465	seq_puts(m, "\nreceive list 'rx_eff':\n");
466
467	rcu_read_lock();
468
469	/* eff receive list for 'all' CAN devices (dev == NULL) */
470	d = &can_rx_alldev_list;
471	can_rcvlist_proc_show_array(m, NULL, d->rx_eff, ARRAY_SIZE(d->rx_eff));
472
473	/* eff receive list for registered CAN devices */
474	for_each_netdev_rcu(&init_net, dev) {
475		if (dev->type == ARPHRD_CAN && dev->ml_priv) {
476			d = dev->ml_priv;
477			can_rcvlist_proc_show_array(m, dev, d->rx_eff,
478						    ARRAY_SIZE(d->rx_eff));
479		}
480	}
481
482	rcu_read_unlock();
483
484	seq_putc(m, '\n');
485	return 0;
486}
487
488static int can_rcvlist_eff_proc_open(struct inode *inode, struct file *file)
489{
490	return single_open(file, can_rcvlist_eff_proc_show, NULL);
491}
492
493static const struct file_operations can_rcvlist_eff_proc_fops = {
494	.owner		= THIS_MODULE,
495	.open		= can_rcvlist_eff_proc_open,
496	.read		= seq_read,
497	.llseek		= seq_lseek,
498	.release	= single_release,
499};
500
501/*
502 * proc utility functions
503 */
504
505static void can_remove_proc_readentry(const char *name)
506{
507	if (can_dir)
508		remove_proc_entry(name, can_dir);
509}
510
511/*
512 * can_init_proc - create main CAN proc directory and procfs entries
513 */
514void can_init_proc(void)
515{
516	/* create /proc/net/can directory */
517	can_dir = proc_mkdir("can", init_net.proc_net);
518
519	if (!can_dir) {
520		printk(KERN_INFO "can: failed to create /proc/net/can . "
521		       "CONFIG_PROC_FS missing?\n");
522		return;
523	}
524
525	/* own procfs entries from the AF_CAN core */
526	pde_version     = proc_create(CAN_PROC_VERSION, 0644, can_dir,
527				      &can_version_proc_fops);
528	pde_stats       = proc_create(CAN_PROC_STATS, 0644, can_dir,
529				      &can_stats_proc_fops);
530	pde_reset_stats = proc_create(CAN_PROC_RESET_STATS, 0644, can_dir,
531				      &can_reset_stats_proc_fops);
532	pde_rcvlist_err = proc_create_data(CAN_PROC_RCVLIST_ERR, 0644, can_dir,
533					   &can_rcvlist_proc_fops, (void *)RX_ERR);
534	pde_rcvlist_all = proc_create_data(CAN_PROC_RCVLIST_ALL, 0644, can_dir,
535					   &can_rcvlist_proc_fops, (void *)RX_ALL);
536	pde_rcvlist_fil = proc_create_data(CAN_PROC_RCVLIST_FIL, 0644, can_dir,
537					   &can_rcvlist_proc_fops, (void *)RX_FIL);
538	pde_rcvlist_inv = proc_create_data(CAN_PROC_RCVLIST_INV, 0644, can_dir,
539					   &can_rcvlist_proc_fops, (void *)RX_INV);
540	pde_rcvlist_eff = proc_create(CAN_PROC_RCVLIST_EFF, 0644, can_dir,
541				      &can_rcvlist_eff_proc_fops);
542	pde_rcvlist_sff = proc_create(CAN_PROC_RCVLIST_SFF, 0644, can_dir,
543				      &can_rcvlist_sff_proc_fops);
544}
545
546/*
547 * can_remove_proc - remove procfs entries and main CAN proc directory
548 */
549void can_remove_proc(void)
550{
551	if (pde_version)
552		can_remove_proc_readentry(CAN_PROC_VERSION);
553
554	if (pde_stats)
555		can_remove_proc_readentry(CAN_PROC_STATS);
556
557	if (pde_reset_stats)
558		can_remove_proc_readentry(CAN_PROC_RESET_STATS);
559
560	if (pde_rcvlist_err)
561		can_remove_proc_readentry(CAN_PROC_RCVLIST_ERR);
562
563	if (pde_rcvlist_all)
564		can_remove_proc_readentry(CAN_PROC_RCVLIST_ALL);
565
566	if (pde_rcvlist_fil)
567		can_remove_proc_readentry(CAN_PROC_RCVLIST_FIL);
568
569	if (pde_rcvlist_inv)
570		can_remove_proc_readentry(CAN_PROC_RCVLIST_INV);
571
572	if (pde_rcvlist_eff)
573		can_remove_proc_readentry(CAN_PROC_RCVLIST_EFF);
574
575	if (pde_rcvlist_sff)
576		can_remove_proc_readentry(CAN_PROC_RCVLIST_SFF);
577
578	if (can_dir)
579		remove_proc_entry("can", init_net.proc_net);
580}
581