xref: /openbmc/linux/net/can/proc.c (revision 4f139972b489f8bc2c821aa25ac65018d92af3f7)
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 int user_reset;
66 
67 static const char rx_list_name[][8] = {
68 	[RX_ERR] = "rx_err",
69 	[RX_ALL] = "rx_all",
70 	[RX_FIL] = "rx_fil",
71 	[RX_INV] = "rx_inv",
72 };
73 
74 /*
75  * af_can statistics stuff
76  */
77 
78 static void can_init_stats(void)
79 {
80 	/*
81 	 * This memset function is called from a timer context (when
82 	 * can_stattimer is active which is the default) OR in a process
83 	 * context (reading the proc_fs when can_stattimer is disabled).
84 	 */
85 	memset(&can_stats, 0, sizeof(can_stats));
86 	can_stats.jiffies_init = jiffies;
87 
88 	can_pstats.stats_reset++;
89 
90 	if (user_reset) {
91 		user_reset = 0;
92 		can_pstats.user_reset++;
93 	}
94 }
95 
96 static unsigned long calc_rate(unsigned long oldjif, unsigned long newjif,
97 			       unsigned long count)
98 {
99 	unsigned long rate;
100 
101 	if (oldjif == newjif)
102 		return 0;
103 
104 	/* see can_stat_update() - this should NEVER happen! */
105 	if (count > (ULONG_MAX / HZ)) {
106 		printk(KERN_ERR "can: calc_rate: count exceeded! %ld\n",
107 		       count);
108 		return 99999999;
109 	}
110 
111 	rate = (count * HZ) / (newjif - oldjif);
112 
113 	return rate;
114 }
115 
116 void can_stat_update(unsigned long data)
117 {
118 	unsigned long j = jiffies; /* snapshot */
119 
120 	/* restart counting in timer context on user request */
121 	if (user_reset)
122 		can_init_stats();
123 
124 	/* restart counting on jiffies overflow */
125 	if (j < can_stats.jiffies_init)
126 		can_init_stats();
127 
128 	/* prevent overflow in calc_rate() */
129 	if (can_stats.rx_frames > (ULONG_MAX / HZ))
130 		can_init_stats();
131 
132 	/* prevent overflow in calc_rate() */
133 	if (can_stats.tx_frames > (ULONG_MAX / HZ))
134 		can_init_stats();
135 
136 	/* matches overflow - very improbable */
137 	if (can_stats.matches > (ULONG_MAX / 100))
138 		can_init_stats();
139 
140 	/* calc total values */
141 	if (can_stats.rx_frames)
142 		can_stats.total_rx_match_ratio = (can_stats.matches * 100) /
143 			can_stats.rx_frames;
144 
145 	can_stats.total_tx_rate = calc_rate(can_stats.jiffies_init, j,
146 					    can_stats.tx_frames);
147 	can_stats.total_rx_rate = calc_rate(can_stats.jiffies_init, j,
148 					    can_stats.rx_frames);
149 
150 	/* calc current values */
151 	if (can_stats.rx_frames_delta)
152 		can_stats.current_rx_match_ratio =
153 			(can_stats.matches_delta * 100) /
154 			can_stats.rx_frames_delta;
155 
156 	can_stats.current_tx_rate = calc_rate(0, HZ, can_stats.tx_frames_delta);
157 	can_stats.current_rx_rate = calc_rate(0, HZ, can_stats.rx_frames_delta);
158 
159 	/* check / update maximum values */
160 	if (can_stats.max_tx_rate < can_stats.current_tx_rate)
161 		can_stats.max_tx_rate = can_stats.current_tx_rate;
162 
163 	if (can_stats.max_rx_rate < can_stats.current_rx_rate)
164 		can_stats.max_rx_rate = can_stats.current_rx_rate;
165 
166 	if (can_stats.max_rx_match_ratio < can_stats.current_rx_match_ratio)
167 		can_stats.max_rx_match_ratio = can_stats.current_rx_match_ratio;
168 
169 	/* clear values for 'current rate' calculation */
170 	can_stats.tx_frames_delta = 0;
171 	can_stats.rx_frames_delta = 0;
172 	can_stats.matches_delta   = 0;
173 
174 	/* restart timer (one second) */
175 	mod_timer(&can_stattimer, round_jiffies(jiffies + HZ));
176 }
177 
178 /*
179  * proc read functions
180  */
181 
182 static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list,
183 			      struct net_device *dev)
184 {
185 	struct receiver *r;
186 
187 	hlist_for_each_entry_rcu(r, rx_list, list) {
188 		char *fmt = (r->can_id & CAN_EFF_FLAG)?
189 			"   %-5s  %08x  %08x  %pK  %pK  %8ld  %s\n" :
190 			"   %-5s     %03x    %08x  %pK  %pK  %8ld  %s\n";
191 
192 		seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
193 				r->func, r->data, r->matches, r->ident);
194 	}
195 }
196 
197 static void can_print_recv_banner(struct seq_file *m)
198 {
199 	/*
200 	 *                  can1.  00000000  00000000  00000000
201 	 *                 .......          0  tp20
202 	 */
203 	seq_puts(m, "  device   can_id   can_mask  function"
204 			"  userdata   matches  ident\n");
205 }
206 
207 static int can_stats_proc_show(struct seq_file *m, void *v)
208 {
209 	seq_putc(m, '\n');
210 	seq_printf(m, " %8ld transmitted frames (TXF)\n", can_stats.tx_frames);
211 	seq_printf(m, " %8ld received frames (RXF)\n", can_stats.rx_frames);
212 	seq_printf(m, " %8ld matched frames (RXMF)\n", can_stats.matches);
213 
214 	seq_putc(m, '\n');
215 
216 	if (can_stattimer.function == can_stat_update) {
217 		seq_printf(m, " %8ld %% total match ratio (RXMR)\n",
218 				can_stats.total_rx_match_ratio);
219 
220 		seq_printf(m, " %8ld frames/s total tx rate (TXR)\n",
221 				can_stats.total_tx_rate);
222 		seq_printf(m, " %8ld frames/s total rx rate (RXR)\n",
223 				can_stats.total_rx_rate);
224 
225 		seq_putc(m, '\n');
226 
227 		seq_printf(m, " %8ld %% current match ratio (CRXMR)\n",
228 				can_stats.current_rx_match_ratio);
229 
230 		seq_printf(m, " %8ld frames/s current tx rate (CTXR)\n",
231 				can_stats.current_tx_rate);
232 		seq_printf(m, " %8ld frames/s current rx rate (CRXR)\n",
233 				can_stats.current_rx_rate);
234 
235 		seq_putc(m, '\n');
236 
237 		seq_printf(m, " %8ld %% max match ratio (MRXMR)\n",
238 				can_stats.max_rx_match_ratio);
239 
240 		seq_printf(m, " %8ld frames/s max tx rate (MTXR)\n",
241 				can_stats.max_tx_rate);
242 		seq_printf(m, " %8ld frames/s max rx rate (MRXR)\n",
243 				can_stats.max_rx_rate);
244 
245 		seq_putc(m, '\n');
246 	}
247 
248 	seq_printf(m, " %8ld current receive list entries (CRCV)\n",
249 			can_pstats.rcv_entries);
250 	seq_printf(m, " %8ld maximum receive list entries (MRCV)\n",
251 			can_pstats.rcv_entries_max);
252 
253 	if (can_pstats.stats_reset)
254 		seq_printf(m, "\n %8ld statistic resets (STR)\n",
255 				can_pstats.stats_reset);
256 
257 	if (can_pstats.user_reset)
258 		seq_printf(m, " %8ld user statistic resets (USTR)\n",
259 				can_pstats.user_reset);
260 
261 	seq_putc(m, '\n');
262 	return 0;
263 }
264 
265 static int can_stats_proc_open(struct inode *inode, struct file *file)
266 {
267 	return single_open(file, can_stats_proc_show, NULL);
268 }
269 
270 static const struct file_operations can_stats_proc_fops = {
271 	.owner		= THIS_MODULE,
272 	.open		= can_stats_proc_open,
273 	.read		= seq_read,
274 	.llseek		= seq_lseek,
275 	.release	= single_release,
276 };
277 
278 static int can_reset_stats_proc_show(struct seq_file *m, void *v)
279 {
280 	user_reset = 1;
281 
282 	if (can_stattimer.function == can_stat_update) {
283 		seq_printf(m, "Scheduled statistic reset #%ld.\n",
284 				can_pstats.stats_reset + 1);
285 
286 	} else {
287 		if (can_stats.jiffies_init != jiffies)
288 			can_init_stats();
289 
290 		seq_printf(m, "Performed statistic reset #%ld.\n",
291 				can_pstats.stats_reset);
292 	}
293 	return 0;
294 }
295 
296 static int can_reset_stats_proc_open(struct inode *inode, struct file *file)
297 {
298 	return single_open(file, can_reset_stats_proc_show, NULL);
299 }
300 
301 static const struct file_operations can_reset_stats_proc_fops = {
302 	.owner		= THIS_MODULE,
303 	.open		= can_reset_stats_proc_open,
304 	.read		= seq_read,
305 	.llseek		= seq_lseek,
306 	.release	= single_release,
307 };
308 
309 static int can_version_proc_show(struct seq_file *m, void *v)
310 {
311 	seq_printf(m, "%s\n", CAN_VERSION_STRING);
312 	return 0;
313 }
314 
315 static int can_version_proc_open(struct inode *inode, struct file *file)
316 {
317 	return single_open(file, can_version_proc_show, NULL);
318 }
319 
320 static const struct file_operations can_version_proc_fops = {
321 	.owner		= THIS_MODULE,
322 	.open		= can_version_proc_open,
323 	.read		= seq_read,
324 	.llseek		= seq_lseek,
325 	.release	= single_release,
326 };
327 
328 static inline void can_rcvlist_proc_show_one(struct seq_file *m, int idx,
329 					     struct net_device *dev,
330 					     struct dev_rcv_lists *d)
331 {
332 	if (!hlist_empty(&d->rx[idx])) {
333 		can_print_recv_banner(m);
334 		can_print_rcvlist(m, &d->rx[idx], dev);
335 	} else
336 		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
337 
338 }
339 
340 static int can_rcvlist_proc_show(struct seq_file *m, void *v)
341 {
342 	/* double cast to prevent GCC warning */
343 	int idx = (int)(long)PDE_DATA(m->file->f_inode);
344 	struct net_device *dev;
345 	struct dev_rcv_lists *d;
346 	struct net *net = m->private;
347 
348 	seq_printf(m, "\nreceive list '%s':\n", rx_list_name[idx]);
349 
350 	rcu_read_lock();
351 
352 	/* receive list for 'all' CAN devices (dev == NULL) */
353 	d = net->can.can_rx_alldev_list;
354 	can_rcvlist_proc_show_one(m, idx, NULL, d);
355 
356 	/* receive list for registered CAN devices */
357 	for_each_netdev_rcu(net, dev) {
358 		if (dev->type == ARPHRD_CAN && dev->ml_priv)
359 			can_rcvlist_proc_show_one(m, idx, dev, dev->ml_priv);
360 	}
361 
362 	rcu_read_unlock();
363 
364 	seq_putc(m, '\n');
365 	return 0;
366 }
367 
368 static int can_rcvlist_proc_open(struct inode *inode, struct file *file)
369 {
370 	return single_open_net(inode, file, can_rcvlist_proc_show);
371 }
372 
373 static const struct file_operations can_rcvlist_proc_fops = {
374 	.owner		= THIS_MODULE,
375 	.open		= can_rcvlist_proc_open,
376 	.read		= seq_read,
377 	.llseek		= seq_lseek,
378 	.release	= single_release,
379 };
380 
381 static inline void can_rcvlist_proc_show_array(struct seq_file *m,
382 					       struct net_device *dev,
383 					       struct hlist_head *rcv_array,
384 					       unsigned int rcv_array_sz)
385 {
386 	unsigned int i;
387 	int all_empty = 1;
388 
389 	/* check whether at least one list is non-empty */
390 	for (i = 0; i < rcv_array_sz; i++)
391 		if (!hlist_empty(&rcv_array[i])) {
392 			all_empty = 0;
393 			break;
394 		}
395 
396 	if (!all_empty) {
397 		can_print_recv_banner(m);
398 		for (i = 0; i < rcv_array_sz; i++) {
399 			if (!hlist_empty(&rcv_array[i]))
400 				can_print_rcvlist(m, &rcv_array[i], dev);
401 		}
402 	} else
403 		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
404 }
405 
406 static int can_rcvlist_sff_proc_show(struct seq_file *m, void *v)
407 {
408 	struct net_device *dev;
409 	struct dev_rcv_lists *d;
410 	struct net *net = m->private;
411 
412 	/* RX_SFF */
413 	seq_puts(m, "\nreceive list 'rx_sff':\n");
414 
415 	rcu_read_lock();
416 
417 	/* sff receive list for 'all' CAN devices (dev == NULL) */
418 	d = net->can.can_rx_alldev_list;
419 	can_rcvlist_proc_show_array(m, NULL, d->rx_sff, ARRAY_SIZE(d->rx_sff));
420 
421 	/* sff receive list for registered CAN devices */
422 	for_each_netdev_rcu(net, dev) {
423 		if (dev->type == ARPHRD_CAN && dev->ml_priv) {
424 			d = dev->ml_priv;
425 			can_rcvlist_proc_show_array(m, dev, d->rx_sff,
426 						    ARRAY_SIZE(d->rx_sff));
427 		}
428 	}
429 
430 	rcu_read_unlock();
431 
432 	seq_putc(m, '\n');
433 	return 0;
434 }
435 
436 static int can_rcvlist_sff_proc_open(struct inode *inode, struct file *file)
437 {
438 	return single_open_net(inode, file, can_rcvlist_sff_proc_show);
439 }
440 
441 static const struct file_operations can_rcvlist_sff_proc_fops = {
442 	.owner		= THIS_MODULE,
443 	.open		= can_rcvlist_sff_proc_open,
444 	.read		= seq_read,
445 	.llseek		= seq_lseek,
446 	.release	= single_release,
447 };
448 
449 
450 static int can_rcvlist_eff_proc_show(struct seq_file *m, void *v)
451 {
452 	struct net_device *dev;
453 	struct dev_rcv_lists *d;
454 	struct net *net = m->private;
455 
456 	/* RX_EFF */
457 	seq_puts(m, "\nreceive list 'rx_eff':\n");
458 
459 	rcu_read_lock();
460 
461 	/* eff receive list for 'all' CAN devices (dev == NULL) */
462 	d = net->can.can_rx_alldev_list;
463 	can_rcvlist_proc_show_array(m, NULL, d->rx_eff, ARRAY_SIZE(d->rx_eff));
464 
465 	/* eff receive list for registered CAN devices */
466 	for_each_netdev_rcu(net, dev) {
467 		if (dev->type == ARPHRD_CAN && dev->ml_priv) {
468 			d = dev->ml_priv;
469 			can_rcvlist_proc_show_array(m, dev, d->rx_eff,
470 						    ARRAY_SIZE(d->rx_eff));
471 		}
472 	}
473 
474 	rcu_read_unlock();
475 
476 	seq_putc(m, '\n');
477 	return 0;
478 }
479 
480 static int can_rcvlist_eff_proc_open(struct inode *inode, struct file *file)
481 {
482 	return single_open_net(inode, file, can_rcvlist_eff_proc_show);
483 }
484 
485 static const struct file_operations can_rcvlist_eff_proc_fops = {
486 	.owner		= THIS_MODULE,
487 	.open		= can_rcvlist_eff_proc_open,
488 	.read		= seq_read,
489 	.llseek		= seq_lseek,
490 	.release	= single_release,
491 };
492 
493 /*
494  * can_init_proc - create main CAN proc directory and procfs entries
495  */
496 void can_init_proc(struct net *net)
497 {
498 	/* create /proc/net/can directory */
499 	net->can.proc_dir = proc_net_mkdir(net, "can", net->proc_net);
500 
501 	if (!net->can.proc_dir) {
502 		printk(KERN_INFO "can: failed to create /proc/net/can . "
503 			   "CONFIG_PROC_FS missing?\n");
504 		return;
505 	}
506 
507 	/* own procfs entries from the AF_CAN core */
508 	net->can.pde_version     = proc_create(CAN_PROC_VERSION, 0644,
509 					       net->can.proc_dir,
510 					       &can_version_proc_fops);
511 	net->can.pde_stats       = proc_create(CAN_PROC_STATS, 0644,
512 					       net->can.proc_dir,
513 					       &can_stats_proc_fops);
514 	net->can.pde_reset_stats = proc_create(CAN_PROC_RESET_STATS, 0644,
515 					       net->can.proc_dir,
516 					       &can_reset_stats_proc_fops);
517 	net->can.pde_rcvlist_err = proc_create_data(CAN_PROC_RCVLIST_ERR, 0644,
518 						    net->can.proc_dir,
519 						    &can_rcvlist_proc_fops,
520 						    (void *)RX_ERR);
521 	net->can.pde_rcvlist_all = proc_create_data(CAN_PROC_RCVLIST_ALL, 0644,
522 						    net->can.proc_dir,
523 						    &can_rcvlist_proc_fops,
524 						    (void *)RX_ALL);
525 	net->can.pde_rcvlist_fil = proc_create_data(CAN_PROC_RCVLIST_FIL, 0644,
526 						    net->can.proc_dir,
527 						    &can_rcvlist_proc_fops,
528 						    (void *)RX_FIL);
529 	net->can.pde_rcvlist_inv = proc_create_data(CAN_PROC_RCVLIST_INV, 0644,
530 						    net->can.proc_dir,
531 						    &can_rcvlist_proc_fops,
532 						    (void *)RX_INV);
533 	net->can.pde_rcvlist_eff = proc_create(CAN_PROC_RCVLIST_EFF, 0644,
534 					       net->can.proc_dir,
535 					       &can_rcvlist_eff_proc_fops);
536 	net->can.pde_rcvlist_sff = proc_create(CAN_PROC_RCVLIST_SFF, 0644,
537 					       net->can.proc_dir,
538 					       &can_rcvlist_sff_proc_fops);
539 }
540 
541 /*
542  * can_remove_proc - remove procfs entries and main CAN proc directory
543  */
544 void can_remove_proc(struct net *net)
545 {
546 	if (net->can.pde_version)
547 		remove_proc_entry(CAN_PROC_VERSION, net->can.proc_dir);
548 
549 	if (net->can.pde_stats)
550 		remove_proc_entry(CAN_PROC_STATS, net->can.proc_dir);
551 
552 	if (net->can.pde_reset_stats)
553 		remove_proc_entry(CAN_PROC_RESET_STATS, net->can.proc_dir);
554 
555 	if (net->can.pde_rcvlist_err)
556 		remove_proc_entry(CAN_PROC_RCVLIST_ERR, net->can.proc_dir);
557 
558 	if (net->can.pde_rcvlist_all)
559 		remove_proc_entry(CAN_PROC_RCVLIST_ALL, net->can.proc_dir);
560 
561 	if (net->can.pde_rcvlist_fil)
562 		remove_proc_entry(CAN_PROC_RCVLIST_FIL, net->can.proc_dir);
563 
564 	if (net->can.pde_rcvlist_inv)
565 		remove_proc_entry(CAN_PROC_RCVLIST_INV, net->can.proc_dir);
566 
567 	if (net->can.pde_rcvlist_eff)
568 		remove_proc_entry(CAN_PROC_RCVLIST_EFF, net->can.proc_dir);
569 
570 	if (net->can.pde_rcvlist_sff)
571 		remove_proc_entry(CAN_PROC_RCVLIST_SFF, net->can.proc_dir);
572 
573 	if (net->can.proc_dir)
574 		remove_proc_entry("can", net->proc_net);
575 }
576