xref: /openbmc/linux/net/can/proc.c (revision 2572f00d)
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 
65 static struct proc_dir_entry *can_dir;
66 static struct proc_dir_entry *pde_version;
67 static struct proc_dir_entry *pde_stats;
68 static struct proc_dir_entry *pde_reset_stats;
69 static struct proc_dir_entry *pde_rcvlist_all;
70 static struct proc_dir_entry *pde_rcvlist_fil;
71 static struct proc_dir_entry *pde_rcvlist_inv;
72 static struct proc_dir_entry *pde_rcvlist_sff;
73 static struct proc_dir_entry *pde_rcvlist_eff;
74 static struct proc_dir_entry *pde_rcvlist_err;
75 
76 static int user_reset;
77 
78 static 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 
89 static 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 
107 static 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 
127 void 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 
193 static 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 
208 static 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 
218 static 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 
276 static int can_stats_proc_open(struct inode *inode, struct file *file)
277 {
278 	return single_open(file, can_stats_proc_show, NULL);
279 }
280 
281 static 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 
289 static 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 
307 static 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 
312 static 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 
320 static 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 
326 static int can_version_proc_open(struct inode *inode, struct file *file)
327 {
328 	return single_open(file, can_version_proc_show, NULL);
329 }
330 
331 static 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 
339 static 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 
351 static 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 
378 static 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 
383 static 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 
391 static 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 
416 static 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 
445 static 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 
450 static 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 
459 static 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 
488 static 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 
493 static 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 
505 static 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  */
514 void 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  */
549 void 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