xref: /openbmc/linux/net/can/proc.c (revision 565d76cb)
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  * Send feedback to <socketcan-users@lists.berlios.de>
41  *
42  */
43 
44 #include <linux/module.h>
45 #include <linux/proc_fs.h>
46 #include <linux/list.h>
47 #include <linux/rcupdate.h>
48 #include <linux/if_arp.h>
49 #include <linux/can/core.h>
50 
51 #include "af_can.h"
52 
53 /*
54  * proc filenames for the PF_CAN core
55  */
56 
57 #define CAN_PROC_VERSION     "version"
58 #define CAN_PROC_STATS       "stats"
59 #define CAN_PROC_RESET_STATS "reset_stats"
60 #define CAN_PROC_RCVLIST_ALL "rcvlist_all"
61 #define CAN_PROC_RCVLIST_FIL "rcvlist_fil"
62 #define CAN_PROC_RCVLIST_INV "rcvlist_inv"
63 #define CAN_PROC_RCVLIST_SFF "rcvlist_sff"
64 #define CAN_PROC_RCVLIST_EFF "rcvlist_eff"
65 #define CAN_PROC_RCVLIST_ERR "rcvlist_err"
66 
67 static struct proc_dir_entry *can_dir;
68 static struct proc_dir_entry *pde_version;
69 static struct proc_dir_entry *pde_stats;
70 static struct proc_dir_entry *pde_reset_stats;
71 static struct proc_dir_entry *pde_rcvlist_all;
72 static struct proc_dir_entry *pde_rcvlist_fil;
73 static struct proc_dir_entry *pde_rcvlist_inv;
74 static struct proc_dir_entry *pde_rcvlist_sff;
75 static struct proc_dir_entry *pde_rcvlist_eff;
76 static struct proc_dir_entry *pde_rcvlist_err;
77 
78 static int user_reset;
79 
80 static const char rx_list_name[][8] = {
81 	[RX_ERR] = "rx_err",
82 	[RX_ALL] = "rx_all",
83 	[RX_FIL] = "rx_fil",
84 	[RX_INV] = "rx_inv",
85 	[RX_EFF] = "rx_eff",
86 };
87 
88 /* receive filters subscribed for 'all' CAN devices */
89 extern struct dev_rcv_lists can_rx_alldev_list;
90 
91 /*
92  * af_can statistics stuff
93  */
94 
95 static void can_init_stats(void)
96 {
97 	/*
98 	 * This memset function is called from a timer context (when
99 	 * can_stattimer is active which is the default) OR in a process
100 	 * context (reading the proc_fs when can_stattimer is disabled).
101 	 */
102 	memset(&can_stats, 0, sizeof(can_stats));
103 	can_stats.jiffies_init = jiffies;
104 
105 	can_pstats.stats_reset++;
106 
107 	if (user_reset) {
108 		user_reset = 0;
109 		can_pstats.user_reset++;
110 	}
111 }
112 
113 static unsigned long calc_rate(unsigned long oldjif, unsigned long newjif,
114 			       unsigned long count)
115 {
116 	unsigned long rate;
117 
118 	if (oldjif == newjif)
119 		return 0;
120 
121 	/* see can_stat_update() - this should NEVER happen! */
122 	if (count > (ULONG_MAX / HZ)) {
123 		printk(KERN_ERR "can: calc_rate: count exceeded! %ld\n",
124 		       count);
125 		return 99999999;
126 	}
127 
128 	rate = (count * HZ) / (newjif - oldjif);
129 
130 	return rate;
131 }
132 
133 void can_stat_update(unsigned long data)
134 {
135 	unsigned long j = jiffies; /* snapshot */
136 
137 	/* restart counting in timer context on user request */
138 	if (user_reset)
139 		can_init_stats();
140 
141 	/* restart counting on jiffies overflow */
142 	if (j < can_stats.jiffies_init)
143 		can_init_stats();
144 
145 	/* prevent overflow in calc_rate() */
146 	if (can_stats.rx_frames > (ULONG_MAX / HZ))
147 		can_init_stats();
148 
149 	/* prevent overflow in calc_rate() */
150 	if (can_stats.tx_frames > (ULONG_MAX / HZ))
151 		can_init_stats();
152 
153 	/* matches overflow - very improbable */
154 	if (can_stats.matches > (ULONG_MAX / 100))
155 		can_init_stats();
156 
157 	/* calc total values */
158 	if (can_stats.rx_frames)
159 		can_stats.total_rx_match_ratio = (can_stats.matches * 100) /
160 			can_stats.rx_frames;
161 
162 	can_stats.total_tx_rate = calc_rate(can_stats.jiffies_init, j,
163 					    can_stats.tx_frames);
164 	can_stats.total_rx_rate = calc_rate(can_stats.jiffies_init, j,
165 					    can_stats.rx_frames);
166 
167 	/* calc current values */
168 	if (can_stats.rx_frames_delta)
169 		can_stats.current_rx_match_ratio =
170 			(can_stats.matches_delta * 100) /
171 			can_stats.rx_frames_delta;
172 
173 	can_stats.current_tx_rate = calc_rate(0, HZ, can_stats.tx_frames_delta);
174 	can_stats.current_rx_rate = calc_rate(0, HZ, can_stats.rx_frames_delta);
175 
176 	/* check / update maximum values */
177 	if (can_stats.max_tx_rate < can_stats.current_tx_rate)
178 		can_stats.max_tx_rate = can_stats.current_tx_rate;
179 
180 	if (can_stats.max_rx_rate < can_stats.current_rx_rate)
181 		can_stats.max_rx_rate = can_stats.current_rx_rate;
182 
183 	if (can_stats.max_rx_match_ratio < can_stats.current_rx_match_ratio)
184 		can_stats.max_rx_match_ratio = can_stats.current_rx_match_ratio;
185 
186 	/* clear values for 'current rate' calculation */
187 	can_stats.tx_frames_delta = 0;
188 	can_stats.rx_frames_delta = 0;
189 	can_stats.matches_delta   = 0;
190 
191 	/* restart timer (one second) */
192 	mod_timer(&can_stattimer, round_jiffies(jiffies + HZ));
193 }
194 
195 /*
196  * proc read functions
197  */
198 
199 static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list,
200 			      struct net_device *dev)
201 {
202 	struct receiver *r;
203 	struct hlist_node *n;
204 
205 	hlist_for_each_entry_rcu(r, n, rx_list, list) {
206 		char *fmt = (r->can_id & CAN_EFF_FLAG)?
207 			"   %-5s  %08X  %08x  %08x  %08x  %8ld  %s\n" :
208 			"   %-5s     %03X    %08x  %08lx  %08lx  %8ld  %s\n";
209 
210 		seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
211 				(unsigned long)r->func, (unsigned long)r->data,
212 				r->matches, r->ident);
213 	}
214 }
215 
216 static void can_print_recv_banner(struct seq_file *m)
217 {
218 	/*
219 	 *                  can1.  00000000  00000000  00000000
220 	 *                 .......          0  tp20
221 	 */
222 	seq_puts(m, "  device   can_id   can_mask  function"
223 			"  userdata   matches  ident\n");
224 }
225 
226 static int can_stats_proc_show(struct seq_file *m, void *v)
227 {
228 	seq_putc(m, '\n');
229 	seq_printf(m, " %8ld transmitted frames (TXF)\n", can_stats.tx_frames);
230 	seq_printf(m, " %8ld received frames (RXF)\n", can_stats.rx_frames);
231 	seq_printf(m, " %8ld matched frames (RXMF)\n", can_stats.matches);
232 
233 	seq_putc(m, '\n');
234 
235 	if (can_stattimer.function == can_stat_update) {
236 		seq_printf(m, " %8ld %% total match ratio (RXMR)\n",
237 				can_stats.total_rx_match_ratio);
238 
239 		seq_printf(m, " %8ld frames/s total tx rate (TXR)\n",
240 				can_stats.total_tx_rate);
241 		seq_printf(m, " %8ld frames/s total rx rate (RXR)\n",
242 				can_stats.total_rx_rate);
243 
244 		seq_putc(m, '\n');
245 
246 		seq_printf(m, " %8ld %% current match ratio (CRXMR)\n",
247 				can_stats.current_rx_match_ratio);
248 
249 		seq_printf(m, " %8ld frames/s current tx rate (CTXR)\n",
250 				can_stats.current_tx_rate);
251 		seq_printf(m, " %8ld frames/s current rx rate (CRXR)\n",
252 				can_stats.current_rx_rate);
253 
254 		seq_putc(m, '\n');
255 
256 		seq_printf(m, " %8ld %% max match ratio (MRXMR)\n",
257 				can_stats.max_rx_match_ratio);
258 
259 		seq_printf(m, " %8ld frames/s max tx rate (MTXR)\n",
260 				can_stats.max_tx_rate);
261 		seq_printf(m, " %8ld frames/s max rx rate (MRXR)\n",
262 				can_stats.max_rx_rate);
263 
264 		seq_putc(m, '\n');
265 	}
266 
267 	seq_printf(m, " %8ld current receive list entries (CRCV)\n",
268 			can_pstats.rcv_entries);
269 	seq_printf(m, " %8ld maximum receive list entries (MRCV)\n",
270 			can_pstats.rcv_entries_max);
271 
272 	if (can_pstats.stats_reset)
273 		seq_printf(m, "\n %8ld statistic resets (STR)\n",
274 				can_pstats.stats_reset);
275 
276 	if (can_pstats.user_reset)
277 		seq_printf(m, " %8ld user statistic resets (USTR)\n",
278 				can_pstats.user_reset);
279 
280 	seq_putc(m, '\n');
281 	return 0;
282 }
283 
284 static int can_stats_proc_open(struct inode *inode, struct file *file)
285 {
286 	return single_open(file, can_stats_proc_show, NULL);
287 }
288 
289 static const struct file_operations can_stats_proc_fops = {
290 	.owner		= THIS_MODULE,
291 	.open		= can_stats_proc_open,
292 	.read		= seq_read,
293 	.llseek		= seq_lseek,
294 	.release	= single_release,
295 };
296 
297 static int can_reset_stats_proc_show(struct seq_file *m, void *v)
298 {
299 	user_reset = 1;
300 
301 	if (can_stattimer.function == can_stat_update) {
302 		seq_printf(m, "Scheduled statistic reset #%ld.\n",
303 				can_pstats.stats_reset + 1);
304 
305 	} else {
306 		if (can_stats.jiffies_init != jiffies)
307 			can_init_stats();
308 
309 		seq_printf(m, "Performed statistic reset #%ld.\n",
310 				can_pstats.stats_reset);
311 	}
312 	return 0;
313 }
314 
315 static int can_reset_stats_proc_open(struct inode *inode, struct file *file)
316 {
317 	return single_open(file, can_reset_stats_proc_show, NULL);
318 }
319 
320 static const struct file_operations can_reset_stats_proc_fops = {
321 	.owner		= THIS_MODULE,
322 	.open		= can_reset_stats_proc_open,
323 	.read		= seq_read,
324 	.llseek		= seq_lseek,
325 	.release	= single_release,
326 };
327 
328 static int can_version_proc_show(struct seq_file *m, void *v)
329 {
330 	seq_printf(m, "%s\n", CAN_VERSION_STRING);
331 	return 0;
332 }
333 
334 static int can_version_proc_open(struct inode *inode, struct file *file)
335 {
336 	return single_open(file, can_version_proc_show, NULL);
337 }
338 
339 static const struct file_operations can_version_proc_fops = {
340 	.owner		= THIS_MODULE,
341 	.open		= can_version_proc_open,
342 	.read		= seq_read,
343 	.llseek		= seq_lseek,
344 	.release	= single_release,
345 };
346 
347 static inline void can_rcvlist_proc_show_one(struct seq_file *m, int idx,
348 					     struct net_device *dev,
349 					     struct dev_rcv_lists *d)
350 {
351 	if (!hlist_empty(&d->rx[idx])) {
352 		can_print_recv_banner(m);
353 		can_print_rcvlist(m, &d->rx[idx], dev);
354 	} else
355 		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
356 
357 }
358 
359 static int can_rcvlist_proc_show(struct seq_file *m, void *v)
360 {
361 	/* double cast to prevent GCC warning */
362 	int idx = (int)(long)m->private;
363 	struct net_device *dev;
364 	struct dev_rcv_lists *d;
365 
366 	seq_printf(m, "\nreceive list '%s':\n", rx_list_name[idx]);
367 
368 	rcu_read_lock();
369 
370 	/* receive list for 'all' CAN devices (dev == NULL) */
371 	d = &can_rx_alldev_list;
372 	can_rcvlist_proc_show_one(m, idx, NULL, d);
373 
374 	/* receive list for registered CAN devices */
375 	for_each_netdev_rcu(&init_net, dev) {
376 		if (dev->type == ARPHRD_CAN && dev->ml_priv)
377 			can_rcvlist_proc_show_one(m, idx, dev, dev->ml_priv);
378 	}
379 
380 	rcu_read_unlock();
381 
382 	seq_putc(m, '\n');
383 	return 0;
384 }
385 
386 static int can_rcvlist_proc_open(struct inode *inode, struct file *file)
387 {
388 	return single_open(file, can_rcvlist_proc_show, PDE(inode)->data);
389 }
390 
391 static const struct file_operations can_rcvlist_proc_fops = {
392 	.owner		= THIS_MODULE,
393 	.open		= can_rcvlist_proc_open,
394 	.read		= seq_read,
395 	.llseek		= seq_lseek,
396 	.release	= single_release,
397 };
398 
399 static inline void can_rcvlist_sff_proc_show_one(struct seq_file *m,
400 						 struct net_device *dev,
401 						 struct dev_rcv_lists *d)
402 {
403 	int i;
404 	int all_empty = 1;
405 
406 	/* check wether at least one list is non-empty */
407 	for (i = 0; i < 0x800; i++)
408 		if (!hlist_empty(&d->rx_sff[i])) {
409 			all_empty = 0;
410 			break;
411 		}
412 
413 	if (!all_empty) {
414 		can_print_recv_banner(m);
415 		for (i = 0; i < 0x800; i++) {
416 			if (!hlist_empty(&d->rx_sff[i]))
417 				can_print_rcvlist(m, &d->rx_sff[i], dev);
418 		}
419 	} else
420 		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
421 }
422 
423 static int can_rcvlist_sff_proc_show(struct seq_file *m, void *v)
424 {
425 	struct net_device *dev;
426 	struct dev_rcv_lists *d;
427 
428 	/* RX_SFF */
429 	seq_puts(m, "\nreceive list 'rx_sff':\n");
430 
431 	rcu_read_lock();
432 
433 	/* sff receive list for 'all' CAN devices (dev == NULL) */
434 	d = &can_rx_alldev_list;
435 	can_rcvlist_sff_proc_show_one(m, NULL, d);
436 
437 	/* sff receive list for registered CAN devices */
438 	for_each_netdev_rcu(&init_net, dev) {
439 		if (dev->type == ARPHRD_CAN && dev->ml_priv)
440 			can_rcvlist_sff_proc_show_one(m, dev, dev->ml_priv);
441 	}
442 
443 	rcu_read_unlock();
444 
445 	seq_putc(m, '\n');
446 	return 0;
447 }
448 
449 static int can_rcvlist_sff_proc_open(struct inode *inode, struct file *file)
450 {
451 	return single_open(file, can_rcvlist_sff_proc_show, NULL);
452 }
453 
454 static const struct file_operations can_rcvlist_sff_proc_fops = {
455 	.owner		= THIS_MODULE,
456 	.open		= can_rcvlist_sff_proc_open,
457 	.read		= seq_read,
458 	.llseek		= seq_lseek,
459 	.release	= single_release,
460 };
461 
462 /*
463  * proc utility functions
464  */
465 
466 static void can_remove_proc_readentry(const char *name)
467 {
468 	if (can_dir)
469 		remove_proc_entry(name, can_dir);
470 }
471 
472 /*
473  * can_init_proc - create main CAN proc directory and procfs entries
474  */
475 void can_init_proc(void)
476 {
477 	/* create /proc/net/can directory */
478 	can_dir = proc_mkdir("can", init_net.proc_net);
479 
480 	if (!can_dir) {
481 		printk(KERN_INFO "can: failed to create /proc/net/can . "
482 		       "CONFIG_PROC_FS missing?\n");
483 		return;
484 	}
485 
486 	/* own procfs entries from the AF_CAN core */
487 	pde_version     = proc_create(CAN_PROC_VERSION, 0644, can_dir,
488 				      &can_version_proc_fops);
489 	pde_stats       = proc_create(CAN_PROC_STATS, 0644, can_dir,
490 				      &can_stats_proc_fops);
491 	pde_reset_stats = proc_create(CAN_PROC_RESET_STATS, 0644, can_dir,
492 				      &can_reset_stats_proc_fops);
493 	pde_rcvlist_err = proc_create_data(CAN_PROC_RCVLIST_ERR, 0644, can_dir,
494 					   &can_rcvlist_proc_fops, (void *)RX_ERR);
495 	pde_rcvlist_all = proc_create_data(CAN_PROC_RCVLIST_ALL, 0644, can_dir,
496 					   &can_rcvlist_proc_fops, (void *)RX_ALL);
497 	pde_rcvlist_fil = proc_create_data(CAN_PROC_RCVLIST_FIL, 0644, can_dir,
498 					   &can_rcvlist_proc_fops, (void *)RX_FIL);
499 	pde_rcvlist_inv = proc_create_data(CAN_PROC_RCVLIST_INV, 0644, can_dir,
500 					   &can_rcvlist_proc_fops, (void *)RX_INV);
501 	pde_rcvlist_eff = proc_create_data(CAN_PROC_RCVLIST_EFF, 0644, can_dir,
502 					   &can_rcvlist_proc_fops, (void *)RX_EFF);
503 	pde_rcvlist_sff = proc_create(CAN_PROC_RCVLIST_SFF, 0644, can_dir,
504 				      &can_rcvlist_sff_proc_fops);
505 }
506 
507 /*
508  * can_remove_proc - remove procfs entries and main CAN proc directory
509  */
510 void can_remove_proc(void)
511 {
512 	if (pde_version)
513 		can_remove_proc_readentry(CAN_PROC_VERSION);
514 
515 	if (pde_stats)
516 		can_remove_proc_readentry(CAN_PROC_STATS);
517 
518 	if (pde_reset_stats)
519 		can_remove_proc_readentry(CAN_PROC_RESET_STATS);
520 
521 	if (pde_rcvlist_err)
522 		can_remove_proc_readentry(CAN_PROC_RCVLIST_ERR);
523 
524 	if (pde_rcvlist_all)
525 		can_remove_proc_readentry(CAN_PROC_RCVLIST_ALL);
526 
527 	if (pde_rcvlist_fil)
528 		can_remove_proc_readentry(CAN_PROC_RCVLIST_FIL);
529 
530 	if (pde_rcvlist_inv)
531 		can_remove_proc_readentry(CAN_PROC_RCVLIST_INV);
532 
533 	if (pde_rcvlist_eff)
534 		can_remove_proc_readentry(CAN_PROC_RCVLIST_EFF);
535 
536 	if (pde_rcvlist_sff)
537 		can_remove_proc_readentry(CAN_PROC_RCVLIST_SFF);
538 
539 	if (can_dir)
540 		proc_net_remove(&init_net, "can");
541 }
542