xref: /openbmc/linux/net/can/proc.c (revision 22246614)
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/can/core.h>
49 
50 #include "af_can.h"
51 
52 /*
53  * proc filenames for the PF_CAN core
54  */
55 
56 #define CAN_PROC_VERSION     "version"
57 #define CAN_PROC_STATS       "stats"
58 #define CAN_PROC_RESET_STATS "reset_stats"
59 #define CAN_PROC_RCVLIST_ALL "rcvlist_all"
60 #define CAN_PROC_RCVLIST_FIL "rcvlist_fil"
61 #define CAN_PROC_RCVLIST_INV "rcvlist_inv"
62 #define CAN_PROC_RCVLIST_SFF "rcvlist_sff"
63 #define CAN_PROC_RCVLIST_EFF "rcvlist_eff"
64 #define CAN_PROC_RCVLIST_ERR "rcvlist_err"
65 
66 static struct proc_dir_entry *can_dir;
67 static struct proc_dir_entry *pde_version;
68 static struct proc_dir_entry *pde_stats;
69 static struct proc_dir_entry *pde_reset_stats;
70 static struct proc_dir_entry *pde_rcvlist_all;
71 static struct proc_dir_entry *pde_rcvlist_fil;
72 static struct proc_dir_entry *pde_rcvlist_inv;
73 static struct proc_dir_entry *pde_rcvlist_sff;
74 static struct proc_dir_entry *pde_rcvlist_eff;
75 static struct proc_dir_entry *pde_rcvlist_err;
76 
77 static int user_reset;
78 
79 static const char rx_list_name[][8] = {
80 	[RX_ERR] = "rx_err",
81 	[RX_ALL] = "rx_all",
82 	[RX_FIL] = "rx_fil",
83 	[RX_INV] = "rx_inv",
84 	[RX_EFF] = "rx_eff",
85 };
86 
87 /*
88  * af_can statistics stuff
89  */
90 
91 static void can_init_stats(void)
92 {
93 	/*
94 	 * This memset function is called from a timer context (when
95 	 * can_stattimer is active which is the default) OR in a process
96 	 * context (reading the proc_fs when can_stattimer is disabled).
97 	 */
98 	memset(&can_stats, 0, sizeof(can_stats));
99 	can_stats.jiffies_init = jiffies;
100 
101 	can_pstats.stats_reset++;
102 
103 	if (user_reset) {
104 		user_reset = 0;
105 		can_pstats.user_reset++;
106 	}
107 }
108 
109 static unsigned long calc_rate(unsigned long oldjif, unsigned long newjif,
110 			       unsigned long count)
111 {
112 	unsigned long rate;
113 
114 	if (oldjif == newjif)
115 		return 0;
116 
117 	/* see can_stat_update() - this should NEVER happen! */
118 	if (count > (ULONG_MAX / HZ)) {
119 		printk(KERN_ERR "can: calc_rate: count exceeded! %ld\n",
120 		       count);
121 		return 99999999;
122 	}
123 
124 	rate = (count * HZ) / (newjif - oldjif);
125 
126 	return rate;
127 }
128 
129 void can_stat_update(unsigned long data)
130 {
131 	unsigned long j = jiffies; /* snapshot */
132 
133 	/* restart counting in timer context on user request */
134 	if (user_reset)
135 		can_init_stats();
136 
137 	/* restart counting on jiffies overflow */
138 	if (j < can_stats.jiffies_init)
139 		can_init_stats();
140 
141 	/* prevent overflow in calc_rate() */
142 	if (can_stats.rx_frames > (ULONG_MAX / HZ))
143 		can_init_stats();
144 
145 	/* prevent overflow in calc_rate() */
146 	if (can_stats.tx_frames > (ULONG_MAX / HZ))
147 		can_init_stats();
148 
149 	/* matches overflow - very improbable */
150 	if (can_stats.matches > (ULONG_MAX / 100))
151 		can_init_stats();
152 
153 	/* calc total values */
154 	if (can_stats.rx_frames)
155 		can_stats.total_rx_match_ratio = (can_stats.matches * 100) /
156 			can_stats.rx_frames;
157 
158 	can_stats.total_tx_rate = calc_rate(can_stats.jiffies_init, j,
159 					    can_stats.tx_frames);
160 	can_stats.total_rx_rate = calc_rate(can_stats.jiffies_init, j,
161 					    can_stats.rx_frames);
162 
163 	/* calc current values */
164 	if (can_stats.rx_frames_delta)
165 		can_stats.current_rx_match_ratio =
166 			(can_stats.matches_delta * 100) /
167 			can_stats.rx_frames_delta;
168 
169 	can_stats.current_tx_rate = calc_rate(0, HZ, can_stats.tx_frames_delta);
170 	can_stats.current_rx_rate = calc_rate(0, HZ, can_stats.rx_frames_delta);
171 
172 	/* check / update maximum values */
173 	if (can_stats.max_tx_rate < can_stats.current_tx_rate)
174 		can_stats.max_tx_rate = can_stats.current_tx_rate;
175 
176 	if (can_stats.max_rx_rate < can_stats.current_rx_rate)
177 		can_stats.max_rx_rate = can_stats.current_rx_rate;
178 
179 	if (can_stats.max_rx_match_ratio < can_stats.current_rx_match_ratio)
180 		can_stats.max_rx_match_ratio = can_stats.current_rx_match_ratio;
181 
182 	/* clear values for 'current rate' calculation */
183 	can_stats.tx_frames_delta = 0;
184 	can_stats.rx_frames_delta = 0;
185 	can_stats.matches_delta   = 0;
186 
187 	/* restart timer (one second) */
188 	mod_timer(&can_stattimer, round_jiffies(jiffies + HZ));
189 }
190 
191 /*
192  * proc read functions
193  *
194  * From known use-cases we expect about 10 entries in a receive list to be
195  * printed in the proc_fs. So PAGE_SIZE is definitely enough space here.
196  *
197  */
198 
199 static int can_print_rcvlist(char *page, int len, struct hlist_head *rx_list,
200 			     struct net_device *dev)
201 {
202 	struct receiver *r;
203 	struct hlist_node *n;
204 
205 	rcu_read_lock();
206 	hlist_for_each_entry_rcu(r, n, rx_list, list) {
207 		char *fmt = (r->can_id & CAN_EFF_FLAG)?
208 			"   %-5s  %08X  %08x  %08x  %08x  %8ld  %s\n" :
209 			"   %-5s     %03X    %08x  %08lx  %08lx  %8ld  %s\n";
210 
211 		len += snprintf(page + len, PAGE_SIZE - len, fmt,
212 				DNAME(dev), r->can_id, r->mask,
213 				(unsigned long)r->func, (unsigned long)r->data,
214 				r->matches, r->ident);
215 
216 		/* does a typical line fit into the current buffer? */
217 
218 		/* 100 Bytes before end of buffer */
219 		if (len > PAGE_SIZE - 100) {
220 			/* mark output cut off */
221 			len += snprintf(page + len, PAGE_SIZE - len,
222 					"   (..)\n");
223 			break;
224 		}
225 	}
226 	rcu_read_unlock();
227 
228 	return len;
229 }
230 
231 static int can_print_recv_banner(char *page, int len)
232 {
233 	/*
234 	 *                  can1.  00000000  00000000  00000000
235 	 *                 .......          0  tp20
236 	 */
237 	len += snprintf(page + len, PAGE_SIZE - len,
238 			"  device   can_id   can_mask  function"
239 			"  userdata   matches  ident\n");
240 
241 	return len;
242 }
243 
244 static int can_proc_read_stats(char *page, char **start, off_t off,
245 			       int count, int *eof, void *data)
246 {
247 	int len = 0;
248 
249 	len += snprintf(page + len, PAGE_SIZE - len, "\n");
250 	len += snprintf(page + len, PAGE_SIZE - len,
251 			" %8ld transmitted frames (TXF)\n",
252 			can_stats.tx_frames);
253 	len += snprintf(page + len, PAGE_SIZE - len,
254 			" %8ld received frames (RXF)\n", can_stats.rx_frames);
255 	len += snprintf(page + len, PAGE_SIZE - len,
256 			" %8ld matched frames (RXMF)\n", can_stats.matches);
257 
258 	len += snprintf(page + len, PAGE_SIZE - len, "\n");
259 
260 	if (can_stattimer.function == can_stat_update) {
261 		len += snprintf(page + len, PAGE_SIZE - len,
262 				" %8ld %% total match ratio (RXMR)\n",
263 				can_stats.total_rx_match_ratio);
264 
265 		len += snprintf(page + len, PAGE_SIZE - len,
266 				" %8ld frames/s total tx rate (TXR)\n",
267 				can_stats.total_tx_rate);
268 		len += snprintf(page + len, PAGE_SIZE - len,
269 				" %8ld frames/s total rx rate (RXR)\n",
270 				can_stats.total_rx_rate);
271 
272 		len += snprintf(page + len, PAGE_SIZE - len, "\n");
273 
274 		len += snprintf(page + len, PAGE_SIZE - len,
275 				" %8ld %% current match ratio (CRXMR)\n",
276 				can_stats.current_rx_match_ratio);
277 
278 		len += snprintf(page + len, PAGE_SIZE - len,
279 				" %8ld frames/s current tx rate (CTXR)\n",
280 				can_stats.current_tx_rate);
281 		len += snprintf(page + len, PAGE_SIZE - len,
282 				" %8ld frames/s current rx rate (CRXR)\n",
283 				can_stats.current_rx_rate);
284 
285 		len += snprintf(page + len, PAGE_SIZE - len, "\n");
286 
287 		len += snprintf(page + len, PAGE_SIZE - len,
288 				" %8ld %% max match ratio (MRXMR)\n",
289 				can_stats.max_rx_match_ratio);
290 
291 		len += snprintf(page + len, PAGE_SIZE - len,
292 				" %8ld frames/s max tx rate (MTXR)\n",
293 				can_stats.max_tx_rate);
294 		len += snprintf(page + len, PAGE_SIZE - len,
295 				" %8ld frames/s max rx rate (MRXR)\n",
296 				can_stats.max_rx_rate);
297 
298 		len += snprintf(page + len, PAGE_SIZE - len, "\n");
299 	}
300 
301 	len += snprintf(page + len, PAGE_SIZE - len,
302 			" %8ld current receive list entries (CRCV)\n",
303 			can_pstats.rcv_entries);
304 	len += snprintf(page + len, PAGE_SIZE - len,
305 			" %8ld maximum receive list entries (MRCV)\n",
306 			can_pstats.rcv_entries_max);
307 
308 	if (can_pstats.stats_reset)
309 		len += snprintf(page + len, PAGE_SIZE - len,
310 				"\n %8ld statistic resets (STR)\n",
311 				can_pstats.stats_reset);
312 
313 	if (can_pstats.user_reset)
314 		len += snprintf(page + len, PAGE_SIZE - len,
315 				" %8ld user statistic resets (USTR)\n",
316 				can_pstats.user_reset);
317 
318 	len += snprintf(page + len, PAGE_SIZE - len, "\n");
319 
320 	*eof = 1;
321 	return len;
322 }
323 
324 static int can_proc_read_reset_stats(char *page, char **start, off_t off,
325 				     int count, int *eof, void *data)
326 {
327 	int len = 0;
328 
329 	user_reset = 1;
330 
331 	if (can_stattimer.function == can_stat_update) {
332 		len += snprintf(page + len, PAGE_SIZE - len,
333 				"Scheduled statistic reset #%ld.\n",
334 				can_pstats.stats_reset + 1);
335 
336 	} else {
337 		if (can_stats.jiffies_init != jiffies)
338 			can_init_stats();
339 
340 		len += snprintf(page + len, PAGE_SIZE - len,
341 				"Performed statistic reset #%ld.\n",
342 				can_pstats.stats_reset);
343 	}
344 
345 	*eof = 1;
346 	return len;
347 }
348 
349 static int can_proc_read_version(char *page, char **start, off_t off,
350 				 int count, int *eof, void *data)
351 {
352 	int len = 0;
353 
354 	len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
355 			CAN_VERSION_STRING);
356 	*eof = 1;
357 	return len;
358 }
359 
360 static int can_proc_read_rcvlist(char *page, char **start, off_t off,
361 				 int count, int *eof, void *data)
362 {
363 	/* double cast to prevent GCC warning */
364 	int idx = (int)(long)data;
365 	int len = 0;
366 	struct dev_rcv_lists *d;
367 	struct hlist_node *n;
368 
369 	len += snprintf(page + len, PAGE_SIZE - len,
370 			"\nreceive list '%s':\n", rx_list_name[idx]);
371 
372 	rcu_read_lock();
373 	hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) {
374 
375 		if (!hlist_empty(&d->rx[idx])) {
376 			len = can_print_recv_banner(page, len);
377 			len = can_print_rcvlist(page, len, &d->rx[idx], d->dev);
378 		} else
379 			len += snprintf(page + len, PAGE_SIZE - len,
380 					"  (%s: no entry)\n", DNAME(d->dev));
381 
382 		/* exit on end of buffer? */
383 		if (len > PAGE_SIZE - 100)
384 			break;
385 	}
386 	rcu_read_unlock();
387 
388 	len += snprintf(page + len, PAGE_SIZE - len, "\n");
389 
390 	*eof = 1;
391 	return len;
392 }
393 
394 static int can_proc_read_rcvlist_sff(char *page, char **start, off_t off,
395 				     int count, int *eof, void *data)
396 {
397 	int len = 0;
398 	struct dev_rcv_lists *d;
399 	struct hlist_node *n;
400 
401 	/* RX_SFF */
402 	len += snprintf(page + len, PAGE_SIZE - len,
403 			"\nreceive list 'rx_sff':\n");
404 
405 	rcu_read_lock();
406 	hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) {
407 		int i, all_empty = 1;
408 		/* check wether at least one list is non-empty */
409 		for (i = 0; i < 0x800; i++)
410 			if (!hlist_empty(&d->rx_sff[i])) {
411 				all_empty = 0;
412 				break;
413 			}
414 
415 		if (!all_empty) {
416 			len = can_print_recv_banner(page, len);
417 			for (i = 0; i < 0x800; i++) {
418 				if (!hlist_empty(&d->rx_sff[i]) &&
419 				    len < PAGE_SIZE - 100)
420 					len = can_print_rcvlist(page, len,
421 								&d->rx_sff[i],
422 								d->dev);
423 			}
424 		} else
425 			len += snprintf(page + len, PAGE_SIZE - len,
426 					"  (%s: no entry)\n", DNAME(d->dev));
427 
428 		/* exit on end of buffer? */
429 		if (len > PAGE_SIZE - 100)
430 			break;
431 	}
432 	rcu_read_unlock();
433 
434 	len += snprintf(page + len, PAGE_SIZE - len, "\n");
435 
436 	*eof = 1;
437 	return len;
438 }
439 
440 /*
441  * proc utility functions
442  */
443 
444 static struct proc_dir_entry *can_create_proc_readentry(const char *name,
445 							mode_t mode,
446 							read_proc_t *read_proc,
447 							void *data)
448 {
449 	if (can_dir)
450 		return create_proc_read_entry(name, mode, can_dir, read_proc,
451 					      data);
452 	else
453 		return NULL;
454 }
455 
456 static void can_remove_proc_readentry(const char *name)
457 {
458 	if (can_dir)
459 		remove_proc_entry(name, can_dir);
460 }
461 
462 /*
463  * can_init_proc - create main CAN proc directory and procfs entries
464  */
465 void can_init_proc(void)
466 {
467 	/* create /proc/net/can directory */
468 	can_dir = proc_mkdir("can", init_net.proc_net);
469 
470 	if (!can_dir) {
471 		printk(KERN_INFO "can: failed to create /proc/net/can . "
472 		       "CONFIG_PROC_FS missing?\n");
473 		return;
474 	}
475 
476 	can_dir->owner = THIS_MODULE;
477 
478 	/* own procfs entries from the AF_CAN core */
479 	pde_version     = can_create_proc_readentry(CAN_PROC_VERSION, 0644,
480 					can_proc_read_version, NULL);
481 	pde_stats       = can_create_proc_readentry(CAN_PROC_STATS, 0644,
482 					can_proc_read_stats, NULL);
483 	pde_reset_stats = can_create_proc_readentry(CAN_PROC_RESET_STATS, 0644,
484 					can_proc_read_reset_stats, NULL);
485 	pde_rcvlist_err = can_create_proc_readentry(CAN_PROC_RCVLIST_ERR, 0644,
486 					can_proc_read_rcvlist, (void *)RX_ERR);
487 	pde_rcvlist_all = can_create_proc_readentry(CAN_PROC_RCVLIST_ALL, 0644,
488 					can_proc_read_rcvlist, (void *)RX_ALL);
489 	pde_rcvlist_fil = can_create_proc_readentry(CAN_PROC_RCVLIST_FIL, 0644,
490 					can_proc_read_rcvlist, (void *)RX_FIL);
491 	pde_rcvlist_inv = can_create_proc_readentry(CAN_PROC_RCVLIST_INV, 0644,
492 					can_proc_read_rcvlist, (void *)RX_INV);
493 	pde_rcvlist_eff = can_create_proc_readentry(CAN_PROC_RCVLIST_EFF, 0644,
494 					can_proc_read_rcvlist, (void *)RX_EFF);
495 	pde_rcvlist_sff = can_create_proc_readentry(CAN_PROC_RCVLIST_SFF, 0644,
496 					can_proc_read_rcvlist_sff, NULL);
497 }
498 
499 /*
500  * can_remove_proc - remove procfs entries and main CAN proc directory
501  */
502 void can_remove_proc(void)
503 {
504 	if (pde_version)
505 		can_remove_proc_readentry(CAN_PROC_VERSION);
506 
507 	if (pde_stats)
508 		can_remove_proc_readentry(CAN_PROC_STATS);
509 
510 	if (pde_reset_stats)
511 		can_remove_proc_readentry(CAN_PROC_RESET_STATS);
512 
513 	if (pde_rcvlist_err)
514 		can_remove_proc_readentry(CAN_PROC_RCVLIST_ERR);
515 
516 	if (pde_rcvlist_all)
517 		can_remove_proc_readentry(CAN_PROC_RCVLIST_ALL);
518 
519 	if (pde_rcvlist_fil)
520 		can_remove_proc_readentry(CAN_PROC_RCVLIST_FIL);
521 
522 	if (pde_rcvlist_inv)
523 		can_remove_proc_readentry(CAN_PROC_RCVLIST_INV);
524 
525 	if (pde_rcvlist_eff)
526 		can_remove_proc_readentry(CAN_PROC_RCVLIST_EFF);
527 
528 	if (pde_rcvlist_sff)
529 		can_remove_proc_readentry(CAN_PROC_RCVLIST_SFF);
530 
531 	if (can_dir)
532 		proc_net_remove(&init_net, "can");
533 }
534