xref: /openbmc/linux/net/can/proc.c (revision 9d749629)
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 	struct hlist_node *n;
199 
200 	hlist_for_each_entry_rcu(r, n, rx_list, list) {
201 		char *fmt = (r->can_id & CAN_EFF_FLAG)?
202 			"   %-5s  %08x  %08x  %pK  %pK  %8ld  %s\n" :
203 			"   %-5s     %03x    %08x  %pK  %pK  %8ld  %s\n";
204 
205 		seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
206 				r->func, r->data, r->matches, r->ident);
207 	}
208 }
209 
210 static void can_print_recv_banner(struct seq_file *m)
211 {
212 	/*
213 	 *                  can1.  00000000  00000000  00000000
214 	 *                 .......          0  tp20
215 	 */
216 	seq_puts(m, "  device   can_id   can_mask  function"
217 			"  userdata   matches  ident\n");
218 }
219 
220 static int can_stats_proc_show(struct seq_file *m, void *v)
221 {
222 	seq_putc(m, '\n');
223 	seq_printf(m, " %8ld transmitted frames (TXF)\n", can_stats.tx_frames);
224 	seq_printf(m, " %8ld received frames (RXF)\n", can_stats.rx_frames);
225 	seq_printf(m, " %8ld matched frames (RXMF)\n", can_stats.matches);
226 
227 	seq_putc(m, '\n');
228 
229 	if (can_stattimer.function == can_stat_update) {
230 		seq_printf(m, " %8ld %% total match ratio (RXMR)\n",
231 				can_stats.total_rx_match_ratio);
232 
233 		seq_printf(m, " %8ld frames/s total tx rate (TXR)\n",
234 				can_stats.total_tx_rate);
235 		seq_printf(m, " %8ld frames/s total rx rate (RXR)\n",
236 				can_stats.total_rx_rate);
237 
238 		seq_putc(m, '\n');
239 
240 		seq_printf(m, " %8ld %% current match ratio (CRXMR)\n",
241 				can_stats.current_rx_match_ratio);
242 
243 		seq_printf(m, " %8ld frames/s current tx rate (CTXR)\n",
244 				can_stats.current_tx_rate);
245 		seq_printf(m, " %8ld frames/s current rx rate (CRXR)\n",
246 				can_stats.current_rx_rate);
247 
248 		seq_putc(m, '\n');
249 
250 		seq_printf(m, " %8ld %% max match ratio (MRXMR)\n",
251 				can_stats.max_rx_match_ratio);
252 
253 		seq_printf(m, " %8ld frames/s max tx rate (MTXR)\n",
254 				can_stats.max_tx_rate);
255 		seq_printf(m, " %8ld frames/s max rx rate (MRXR)\n",
256 				can_stats.max_rx_rate);
257 
258 		seq_putc(m, '\n');
259 	}
260 
261 	seq_printf(m, " %8ld current receive list entries (CRCV)\n",
262 			can_pstats.rcv_entries);
263 	seq_printf(m, " %8ld maximum receive list entries (MRCV)\n",
264 			can_pstats.rcv_entries_max);
265 
266 	if (can_pstats.stats_reset)
267 		seq_printf(m, "\n %8ld statistic resets (STR)\n",
268 				can_pstats.stats_reset);
269 
270 	if (can_pstats.user_reset)
271 		seq_printf(m, " %8ld user statistic resets (USTR)\n",
272 				can_pstats.user_reset);
273 
274 	seq_putc(m, '\n');
275 	return 0;
276 }
277 
278 static int can_stats_proc_open(struct inode *inode, struct file *file)
279 {
280 	return single_open(file, can_stats_proc_show, NULL);
281 }
282 
283 static const struct file_operations can_stats_proc_fops = {
284 	.owner		= THIS_MODULE,
285 	.open		= can_stats_proc_open,
286 	.read		= seq_read,
287 	.llseek		= seq_lseek,
288 	.release	= single_release,
289 };
290 
291 static int can_reset_stats_proc_show(struct seq_file *m, void *v)
292 {
293 	user_reset = 1;
294 
295 	if (can_stattimer.function == can_stat_update) {
296 		seq_printf(m, "Scheduled statistic reset #%ld.\n",
297 				can_pstats.stats_reset + 1);
298 
299 	} else {
300 		if (can_stats.jiffies_init != jiffies)
301 			can_init_stats();
302 
303 		seq_printf(m, "Performed statistic reset #%ld.\n",
304 				can_pstats.stats_reset);
305 	}
306 	return 0;
307 }
308 
309 static int can_reset_stats_proc_open(struct inode *inode, struct file *file)
310 {
311 	return single_open(file, can_reset_stats_proc_show, NULL);
312 }
313 
314 static const struct file_operations can_reset_stats_proc_fops = {
315 	.owner		= THIS_MODULE,
316 	.open		= can_reset_stats_proc_open,
317 	.read		= seq_read,
318 	.llseek		= seq_lseek,
319 	.release	= single_release,
320 };
321 
322 static int can_version_proc_show(struct seq_file *m, void *v)
323 {
324 	seq_printf(m, "%s\n", CAN_VERSION_STRING);
325 	return 0;
326 }
327 
328 static int can_version_proc_open(struct inode *inode, struct file *file)
329 {
330 	return single_open(file, can_version_proc_show, NULL);
331 }
332 
333 static const struct file_operations can_version_proc_fops = {
334 	.owner		= THIS_MODULE,
335 	.open		= can_version_proc_open,
336 	.read		= seq_read,
337 	.llseek		= seq_lseek,
338 	.release	= single_release,
339 };
340 
341 static inline void can_rcvlist_proc_show_one(struct seq_file *m, int idx,
342 					     struct net_device *dev,
343 					     struct dev_rcv_lists *d)
344 {
345 	if (!hlist_empty(&d->rx[idx])) {
346 		can_print_recv_banner(m);
347 		can_print_rcvlist(m, &d->rx[idx], dev);
348 	} else
349 		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
350 
351 }
352 
353 static int can_rcvlist_proc_show(struct seq_file *m, void *v)
354 {
355 	/* double cast to prevent GCC warning */
356 	int idx = (int)(long)m->private;
357 	struct net_device *dev;
358 	struct dev_rcv_lists *d;
359 
360 	seq_printf(m, "\nreceive list '%s':\n", rx_list_name[idx]);
361 
362 	rcu_read_lock();
363 
364 	/* receive list for 'all' CAN devices (dev == NULL) */
365 	d = &can_rx_alldev_list;
366 	can_rcvlist_proc_show_one(m, idx, NULL, d);
367 
368 	/* receive list for registered CAN devices */
369 	for_each_netdev_rcu(&init_net, dev) {
370 		if (dev->type == ARPHRD_CAN && dev->ml_priv)
371 			can_rcvlist_proc_show_one(m, idx, dev, dev->ml_priv);
372 	}
373 
374 	rcu_read_unlock();
375 
376 	seq_putc(m, '\n');
377 	return 0;
378 }
379 
380 static int can_rcvlist_proc_open(struct inode *inode, struct file *file)
381 {
382 	return single_open(file, can_rcvlist_proc_show, PDE(inode)->data);
383 }
384 
385 static const struct file_operations can_rcvlist_proc_fops = {
386 	.owner		= THIS_MODULE,
387 	.open		= can_rcvlist_proc_open,
388 	.read		= seq_read,
389 	.llseek		= seq_lseek,
390 	.release	= single_release,
391 };
392 
393 static inline void can_rcvlist_sff_proc_show_one(struct seq_file *m,
394 						 struct net_device *dev,
395 						 struct dev_rcv_lists *d)
396 {
397 	int i;
398 	int all_empty = 1;
399 
400 	/* check whether at least one list is non-empty */
401 	for (i = 0; i < 0x800; i++)
402 		if (!hlist_empty(&d->rx_sff[i])) {
403 			all_empty = 0;
404 			break;
405 		}
406 
407 	if (!all_empty) {
408 		can_print_recv_banner(m);
409 		for (i = 0; i < 0x800; i++) {
410 			if (!hlist_empty(&d->rx_sff[i]))
411 				can_print_rcvlist(m, &d->rx_sff[i], dev);
412 		}
413 	} else
414 		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
415 }
416 
417 static int can_rcvlist_sff_proc_show(struct seq_file *m, void *v)
418 {
419 	struct net_device *dev;
420 	struct dev_rcv_lists *d;
421 
422 	/* RX_SFF */
423 	seq_puts(m, "\nreceive list 'rx_sff':\n");
424 
425 	rcu_read_lock();
426 
427 	/* sff receive list for 'all' CAN devices (dev == NULL) */
428 	d = &can_rx_alldev_list;
429 	can_rcvlist_sff_proc_show_one(m, NULL, d);
430 
431 	/* sff receive list for registered CAN devices */
432 	for_each_netdev_rcu(&init_net, dev) {
433 		if (dev->type == ARPHRD_CAN && dev->ml_priv)
434 			can_rcvlist_sff_proc_show_one(m, dev, dev->ml_priv);
435 	}
436 
437 	rcu_read_unlock();
438 
439 	seq_putc(m, '\n');
440 	return 0;
441 }
442 
443 static int can_rcvlist_sff_proc_open(struct inode *inode, struct file *file)
444 {
445 	return single_open(file, can_rcvlist_sff_proc_show, NULL);
446 }
447 
448 static const struct file_operations can_rcvlist_sff_proc_fops = {
449 	.owner		= THIS_MODULE,
450 	.open		= can_rcvlist_sff_proc_open,
451 	.read		= seq_read,
452 	.llseek		= seq_lseek,
453 	.release	= single_release,
454 };
455 
456 /*
457  * proc utility functions
458  */
459 
460 static void can_remove_proc_readentry(const char *name)
461 {
462 	if (can_dir)
463 		remove_proc_entry(name, can_dir);
464 }
465 
466 /*
467  * can_init_proc - create main CAN proc directory and procfs entries
468  */
469 void can_init_proc(void)
470 {
471 	/* create /proc/net/can directory */
472 	can_dir = proc_mkdir("can", init_net.proc_net);
473 
474 	if (!can_dir) {
475 		printk(KERN_INFO "can: failed to create /proc/net/can . "
476 		       "CONFIG_PROC_FS missing?\n");
477 		return;
478 	}
479 
480 	/* own procfs entries from the AF_CAN core */
481 	pde_version     = proc_create(CAN_PROC_VERSION, 0644, can_dir,
482 				      &can_version_proc_fops);
483 	pde_stats       = proc_create(CAN_PROC_STATS, 0644, can_dir,
484 				      &can_stats_proc_fops);
485 	pde_reset_stats = proc_create(CAN_PROC_RESET_STATS, 0644, can_dir,
486 				      &can_reset_stats_proc_fops);
487 	pde_rcvlist_err = proc_create_data(CAN_PROC_RCVLIST_ERR, 0644, can_dir,
488 					   &can_rcvlist_proc_fops, (void *)RX_ERR);
489 	pde_rcvlist_all = proc_create_data(CAN_PROC_RCVLIST_ALL, 0644, can_dir,
490 					   &can_rcvlist_proc_fops, (void *)RX_ALL);
491 	pde_rcvlist_fil = proc_create_data(CAN_PROC_RCVLIST_FIL, 0644, can_dir,
492 					   &can_rcvlist_proc_fops, (void *)RX_FIL);
493 	pde_rcvlist_inv = proc_create_data(CAN_PROC_RCVLIST_INV, 0644, can_dir,
494 					   &can_rcvlist_proc_fops, (void *)RX_INV);
495 	pde_rcvlist_eff = proc_create_data(CAN_PROC_RCVLIST_EFF, 0644, can_dir,
496 					   &can_rcvlist_proc_fops, (void *)RX_EFF);
497 	pde_rcvlist_sff = proc_create(CAN_PROC_RCVLIST_SFF, 0644, can_dir,
498 				      &can_rcvlist_sff_proc_fops);
499 }
500 
501 /*
502  * can_remove_proc - remove procfs entries and main CAN proc directory
503  */
504 void can_remove_proc(void)
505 {
506 	if (pde_version)
507 		can_remove_proc_readentry(CAN_PROC_VERSION);
508 
509 	if (pde_stats)
510 		can_remove_proc_readentry(CAN_PROC_STATS);
511 
512 	if (pde_reset_stats)
513 		can_remove_proc_readentry(CAN_PROC_RESET_STATS);
514 
515 	if (pde_rcvlist_err)
516 		can_remove_proc_readentry(CAN_PROC_RCVLIST_ERR);
517 
518 	if (pde_rcvlist_all)
519 		can_remove_proc_readentry(CAN_PROC_RCVLIST_ALL);
520 
521 	if (pde_rcvlist_fil)
522 		can_remove_proc_readentry(CAN_PROC_RCVLIST_FIL);
523 
524 	if (pde_rcvlist_inv)
525 		can_remove_proc_readentry(CAN_PROC_RCVLIST_INV);
526 
527 	if (pde_rcvlist_eff)
528 		can_remove_proc_readentry(CAN_PROC_RCVLIST_EFF);
529 
530 	if (pde_rcvlist_sff)
531 		can_remove_proc_readentry(CAN_PROC_RCVLIST_SFF);
532 
533 	if (can_dir)
534 		remove_proc_entry("can", init_net.proc_net);
535 }
536