xref: /openbmc/linux/net/can/proc.c (revision c4ee0af3)
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 	[RX_EFF] = "rx_eff",
84 };
85 
86 /*
87  * af_can statistics stuff
88  */
89 
90 static void can_init_stats(void)
91 {
92 	/*
93 	 * This memset function is called from a timer context (when
94 	 * can_stattimer is active which is the default) OR in a process
95 	 * context (reading the proc_fs when can_stattimer is disabled).
96 	 */
97 	memset(&can_stats, 0, sizeof(can_stats));
98 	can_stats.jiffies_init = jiffies;
99 
100 	can_pstats.stats_reset++;
101 
102 	if (user_reset) {
103 		user_reset = 0;
104 		can_pstats.user_reset++;
105 	}
106 }
107 
108 static unsigned long calc_rate(unsigned long oldjif, unsigned long newjif,
109 			       unsigned long count)
110 {
111 	unsigned long rate;
112 
113 	if (oldjif == newjif)
114 		return 0;
115 
116 	/* see can_stat_update() - this should NEVER happen! */
117 	if (count > (ULONG_MAX / HZ)) {
118 		printk(KERN_ERR "can: calc_rate: count exceeded! %ld\n",
119 		       count);
120 		return 99999999;
121 	}
122 
123 	rate = (count * HZ) / (newjif - oldjif);
124 
125 	return rate;
126 }
127 
128 void can_stat_update(unsigned long data)
129 {
130 	unsigned long j = jiffies; /* snapshot */
131 
132 	/* restart counting in timer context on user request */
133 	if (user_reset)
134 		can_init_stats();
135 
136 	/* restart counting on jiffies overflow */
137 	if (j < can_stats.jiffies_init)
138 		can_init_stats();
139 
140 	/* prevent overflow in calc_rate() */
141 	if (can_stats.rx_frames > (ULONG_MAX / HZ))
142 		can_init_stats();
143 
144 	/* prevent overflow in calc_rate() */
145 	if (can_stats.tx_frames > (ULONG_MAX / HZ))
146 		can_init_stats();
147 
148 	/* matches overflow - very improbable */
149 	if (can_stats.matches > (ULONG_MAX / 100))
150 		can_init_stats();
151 
152 	/* calc total values */
153 	if (can_stats.rx_frames)
154 		can_stats.total_rx_match_ratio = (can_stats.matches * 100) /
155 			can_stats.rx_frames;
156 
157 	can_stats.total_tx_rate = calc_rate(can_stats.jiffies_init, j,
158 					    can_stats.tx_frames);
159 	can_stats.total_rx_rate = calc_rate(can_stats.jiffies_init, j,
160 					    can_stats.rx_frames);
161 
162 	/* calc current values */
163 	if (can_stats.rx_frames_delta)
164 		can_stats.current_rx_match_ratio =
165 			(can_stats.matches_delta * 100) /
166 			can_stats.rx_frames_delta;
167 
168 	can_stats.current_tx_rate = calc_rate(0, HZ, can_stats.tx_frames_delta);
169 	can_stats.current_rx_rate = calc_rate(0, HZ, can_stats.rx_frames_delta);
170 
171 	/* check / update maximum values */
172 	if (can_stats.max_tx_rate < can_stats.current_tx_rate)
173 		can_stats.max_tx_rate = can_stats.current_tx_rate;
174 
175 	if (can_stats.max_rx_rate < can_stats.current_rx_rate)
176 		can_stats.max_rx_rate = can_stats.current_rx_rate;
177 
178 	if (can_stats.max_rx_match_ratio < can_stats.current_rx_match_ratio)
179 		can_stats.max_rx_match_ratio = can_stats.current_rx_match_ratio;
180 
181 	/* clear values for 'current rate' calculation */
182 	can_stats.tx_frames_delta = 0;
183 	can_stats.rx_frames_delta = 0;
184 	can_stats.matches_delta   = 0;
185 
186 	/* restart timer (one second) */
187 	mod_timer(&can_stattimer, round_jiffies(jiffies + HZ));
188 }
189 
190 /*
191  * proc read functions
192  */
193 
194 static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list,
195 			      struct net_device *dev)
196 {
197 	struct receiver *r;
198 
199 	hlist_for_each_entry_rcu(r, rx_list, list) {
200 		char *fmt = (r->can_id & CAN_EFF_FLAG)?
201 			"   %-5s  %08x  %08x  %pK  %pK  %8ld  %s\n" :
202 			"   %-5s     %03x    %08x  %pK  %pK  %8ld  %s\n";
203 
204 		seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
205 				r->func, r->data, r->matches, r->ident);
206 	}
207 }
208 
209 static void can_print_recv_banner(struct seq_file *m)
210 {
211 	/*
212 	 *                  can1.  00000000  00000000  00000000
213 	 *                 .......          0  tp20
214 	 */
215 	seq_puts(m, "  device   can_id   can_mask  function"
216 			"  userdata   matches  ident\n");
217 }
218 
219 static int can_stats_proc_show(struct seq_file *m, void *v)
220 {
221 	seq_putc(m, '\n');
222 	seq_printf(m, " %8ld transmitted frames (TXF)\n", can_stats.tx_frames);
223 	seq_printf(m, " %8ld received frames (RXF)\n", can_stats.rx_frames);
224 	seq_printf(m, " %8ld matched frames (RXMF)\n", can_stats.matches);
225 
226 	seq_putc(m, '\n');
227 
228 	if (can_stattimer.function == can_stat_update) {
229 		seq_printf(m, " %8ld %% total match ratio (RXMR)\n",
230 				can_stats.total_rx_match_ratio);
231 
232 		seq_printf(m, " %8ld frames/s total tx rate (TXR)\n",
233 				can_stats.total_tx_rate);
234 		seq_printf(m, " %8ld frames/s total rx rate (RXR)\n",
235 				can_stats.total_rx_rate);
236 
237 		seq_putc(m, '\n');
238 
239 		seq_printf(m, " %8ld %% current match ratio (CRXMR)\n",
240 				can_stats.current_rx_match_ratio);
241 
242 		seq_printf(m, " %8ld frames/s current tx rate (CTXR)\n",
243 				can_stats.current_tx_rate);
244 		seq_printf(m, " %8ld frames/s current rx rate (CRXR)\n",
245 				can_stats.current_rx_rate);
246 
247 		seq_putc(m, '\n');
248 
249 		seq_printf(m, " %8ld %% max match ratio (MRXMR)\n",
250 				can_stats.max_rx_match_ratio);
251 
252 		seq_printf(m, " %8ld frames/s max tx rate (MTXR)\n",
253 				can_stats.max_tx_rate);
254 		seq_printf(m, " %8ld frames/s max rx rate (MRXR)\n",
255 				can_stats.max_rx_rate);
256 
257 		seq_putc(m, '\n');
258 	}
259 
260 	seq_printf(m, " %8ld current receive list entries (CRCV)\n",
261 			can_pstats.rcv_entries);
262 	seq_printf(m, " %8ld maximum receive list entries (MRCV)\n",
263 			can_pstats.rcv_entries_max);
264 
265 	if (can_pstats.stats_reset)
266 		seq_printf(m, "\n %8ld statistic resets (STR)\n",
267 				can_pstats.stats_reset);
268 
269 	if (can_pstats.user_reset)
270 		seq_printf(m, " %8ld user statistic resets (USTR)\n",
271 				can_pstats.user_reset);
272 
273 	seq_putc(m, '\n');
274 	return 0;
275 }
276 
277 static int can_stats_proc_open(struct inode *inode, struct file *file)
278 {
279 	return single_open(file, can_stats_proc_show, NULL);
280 }
281 
282 static const struct file_operations can_stats_proc_fops = {
283 	.owner		= THIS_MODULE,
284 	.open		= can_stats_proc_open,
285 	.read		= seq_read,
286 	.llseek		= seq_lseek,
287 	.release	= single_release,
288 };
289 
290 static int can_reset_stats_proc_show(struct seq_file *m, void *v)
291 {
292 	user_reset = 1;
293 
294 	if (can_stattimer.function == can_stat_update) {
295 		seq_printf(m, "Scheduled statistic reset #%ld.\n",
296 				can_pstats.stats_reset + 1);
297 
298 	} else {
299 		if (can_stats.jiffies_init != jiffies)
300 			can_init_stats();
301 
302 		seq_printf(m, "Performed statistic reset #%ld.\n",
303 				can_pstats.stats_reset);
304 	}
305 	return 0;
306 }
307 
308 static int can_reset_stats_proc_open(struct inode *inode, struct file *file)
309 {
310 	return single_open(file, can_reset_stats_proc_show, NULL);
311 }
312 
313 static const struct file_operations can_reset_stats_proc_fops = {
314 	.owner		= THIS_MODULE,
315 	.open		= can_reset_stats_proc_open,
316 	.read		= seq_read,
317 	.llseek		= seq_lseek,
318 	.release	= single_release,
319 };
320 
321 static int can_version_proc_show(struct seq_file *m, void *v)
322 {
323 	seq_printf(m, "%s\n", CAN_VERSION_STRING);
324 	return 0;
325 }
326 
327 static int can_version_proc_open(struct inode *inode, struct file *file)
328 {
329 	return single_open(file, can_version_proc_show, NULL);
330 }
331 
332 static const struct file_operations can_version_proc_fops = {
333 	.owner		= THIS_MODULE,
334 	.open		= can_version_proc_open,
335 	.read		= seq_read,
336 	.llseek		= seq_lseek,
337 	.release	= single_release,
338 };
339 
340 static inline void can_rcvlist_proc_show_one(struct seq_file *m, int idx,
341 					     struct net_device *dev,
342 					     struct dev_rcv_lists *d)
343 {
344 	if (!hlist_empty(&d->rx[idx])) {
345 		can_print_recv_banner(m);
346 		can_print_rcvlist(m, &d->rx[idx], dev);
347 	} else
348 		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
349 
350 }
351 
352 static int can_rcvlist_proc_show(struct seq_file *m, void *v)
353 {
354 	/* double cast to prevent GCC warning */
355 	int idx = (int)(long)m->private;
356 	struct net_device *dev;
357 	struct dev_rcv_lists *d;
358 
359 	seq_printf(m, "\nreceive list '%s':\n", rx_list_name[idx]);
360 
361 	rcu_read_lock();
362 
363 	/* receive list for 'all' CAN devices (dev == NULL) */
364 	d = &can_rx_alldev_list;
365 	can_rcvlist_proc_show_one(m, idx, NULL, d);
366 
367 	/* receive list for registered CAN devices */
368 	for_each_netdev_rcu(&init_net, dev) {
369 		if (dev->type == ARPHRD_CAN && dev->ml_priv)
370 			can_rcvlist_proc_show_one(m, idx, dev, dev->ml_priv);
371 	}
372 
373 	rcu_read_unlock();
374 
375 	seq_putc(m, '\n');
376 	return 0;
377 }
378 
379 static int can_rcvlist_proc_open(struct inode *inode, struct file *file)
380 {
381 	return single_open(file, can_rcvlist_proc_show, PDE_DATA(inode));
382 }
383 
384 static const struct file_operations can_rcvlist_proc_fops = {
385 	.owner		= THIS_MODULE,
386 	.open		= can_rcvlist_proc_open,
387 	.read		= seq_read,
388 	.llseek		= seq_lseek,
389 	.release	= single_release,
390 };
391 
392 static inline void can_rcvlist_sff_proc_show_one(struct seq_file *m,
393 						 struct net_device *dev,
394 						 struct dev_rcv_lists *d)
395 {
396 	int i;
397 	int all_empty = 1;
398 
399 	/* check whether at least one list is non-empty */
400 	for (i = 0; i < 0x800; i++)
401 		if (!hlist_empty(&d->rx_sff[i])) {
402 			all_empty = 0;
403 			break;
404 		}
405 
406 	if (!all_empty) {
407 		can_print_recv_banner(m);
408 		for (i = 0; i < 0x800; i++) {
409 			if (!hlist_empty(&d->rx_sff[i]))
410 				can_print_rcvlist(m, &d->rx_sff[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_sff_proc_show_one(m, NULL, d);
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 			can_rcvlist_sff_proc_show_one(m, dev, dev->ml_priv);
434 	}
435 
436 	rcu_read_unlock();
437 
438 	seq_putc(m, '\n');
439 	return 0;
440 }
441 
442 static int can_rcvlist_sff_proc_open(struct inode *inode, struct file *file)
443 {
444 	return single_open(file, can_rcvlist_sff_proc_show, NULL);
445 }
446 
447 static const struct file_operations can_rcvlist_sff_proc_fops = {
448 	.owner		= THIS_MODULE,
449 	.open		= can_rcvlist_sff_proc_open,
450 	.read		= seq_read,
451 	.llseek		= seq_lseek,
452 	.release	= single_release,
453 };
454 
455 /*
456  * proc utility functions
457  */
458 
459 static void can_remove_proc_readentry(const char *name)
460 {
461 	if (can_dir)
462 		remove_proc_entry(name, can_dir);
463 }
464 
465 /*
466  * can_init_proc - create main CAN proc directory and procfs entries
467  */
468 void can_init_proc(void)
469 {
470 	/* create /proc/net/can directory */
471 	can_dir = proc_mkdir("can", init_net.proc_net);
472 
473 	if (!can_dir) {
474 		printk(KERN_INFO "can: failed to create /proc/net/can . "
475 		       "CONFIG_PROC_FS missing?\n");
476 		return;
477 	}
478 
479 	/* own procfs entries from the AF_CAN core */
480 	pde_version     = proc_create(CAN_PROC_VERSION, 0644, can_dir,
481 				      &can_version_proc_fops);
482 	pde_stats       = proc_create(CAN_PROC_STATS, 0644, can_dir,
483 				      &can_stats_proc_fops);
484 	pde_reset_stats = proc_create(CAN_PROC_RESET_STATS, 0644, can_dir,
485 				      &can_reset_stats_proc_fops);
486 	pde_rcvlist_err = proc_create_data(CAN_PROC_RCVLIST_ERR, 0644, can_dir,
487 					   &can_rcvlist_proc_fops, (void *)RX_ERR);
488 	pde_rcvlist_all = proc_create_data(CAN_PROC_RCVLIST_ALL, 0644, can_dir,
489 					   &can_rcvlist_proc_fops, (void *)RX_ALL);
490 	pde_rcvlist_fil = proc_create_data(CAN_PROC_RCVLIST_FIL, 0644, can_dir,
491 					   &can_rcvlist_proc_fops, (void *)RX_FIL);
492 	pde_rcvlist_inv = proc_create_data(CAN_PROC_RCVLIST_INV, 0644, can_dir,
493 					   &can_rcvlist_proc_fops, (void *)RX_INV);
494 	pde_rcvlist_eff = proc_create_data(CAN_PROC_RCVLIST_EFF, 0644, can_dir,
495 					   &can_rcvlist_proc_fops, (void *)RX_EFF);
496 	pde_rcvlist_sff = proc_create(CAN_PROC_RCVLIST_SFF, 0644, can_dir,
497 				      &can_rcvlist_sff_proc_fops);
498 }
499 
500 /*
501  * can_remove_proc - remove procfs entries and main CAN proc directory
502  */
503 void can_remove_proc(void)
504 {
505 	if (pde_version)
506 		can_remove_proc_readentry(CAN_PROC_VERSION);
507 
508 	if (pde_stats)
509 		can_remove_proc_readentry(CAN_PROC_STATS);
510 
511 	if (pde_reset_stats)
512 		can_remove_proc_readentry(CAN_PROC_RESET_STATS);
513 
514 	if (pde_rcvlist_err)
515 		can_remove_proc_readentry(CAN_PROC_RCVLIST_ERR);
516 
517 	if (pde_rcvlist_all)
518 		can_remove_proc_readentry(CAN_PROC_RCVLIST_ALL);
519 
520 	if (pde_rcvlist_fil)
521 		can_remove_proc_readentry(CAN_PROC_RCVLIST_FIL);
522 
523 	if (pde_rcvlist_inv)
524 		can_remove_proc_readentry(CAN_PROC_RCVLIST_INV);
525 
526 	if (pde_rcvlist_eff)
527 		can_remove_proc_readentry(CAN_PROC_RCVLIST_EFF);
528 
529 	if (pde_rcvlist_sff)
530 		can_remove_proc_readentry(CAN_PROC_RCVLIST_SFF);
531 
532 	if (can_dir)
533 		remove_proc_entry("can", init_net.proc_net);
534 }
535