xref: /openbmc/linux/net/can/proc.c (revision 9d56dd3b083a3bec56e9da35ce07baca81030b03)
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 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 	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 		seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
212 				(unsigned long)r->func, (unsigned long)r->data,
213 				r->matches, r->ident);
214 	}
215 	rcu_read_unlock();
216 }
217 
218 static void can_print_recv_banner(struct seq_file *m)
219 {
220 	/*
221 	 *                  can1.  00000000  00000000  00000000
222 	 *                 .......          0  tp20
223 	 */
224 	seq_puts(m, "  device   can_id   can_mask  function"
225 			"  userdata   matches  ident\n");
226 }
227 
228 static int can_stats_proc_show(struct seq_file *m, void *v)
229 {
230 	seq_putc(m, '\n');
231 	seq_printf(m, " %8ld transmitted frames (TXF)\n", can_stats.tx_frames);
232 	seq_printf(m, " %8ld received frames (RXF)\n", can_stats.rx_frames);
233 	seq_printf(m, " %8ld matched frames (RXMF)\n", can_stats.matches);
234 
235 	seq_putc(m, '\n');
236 
237 	if (can_stattimer.function == can_stat_update) {
238 		seq_printf(m, " %8ld %% total match ratio (RXMR)\n",
239 				can_stats.total_rx_match_ratio);
240 
241 		seq_printf(m, " %8ld frames/s total tx rate (TXR)\n",
242 				can_stats.total_tx_rate);
243 		seq_printf(m, " %8ld frames/s total rx rate (RXR)\n",
244 				can_stats.total_rx_rate);
245 
246 		seq_putc(m, '\n');
247 
248 		seq_printf(m, " %8ld %% current match ratio (CRXMR)\n",
249 				can_stats.current_rx_match_ratio);
250 
251 		seq_printf(m, " %8ld frames/s current tx rate (CTXR)\n",
252 				can_stats.current_tx_rate);
253 		seq_printf(m, " %8ld frames/s current rx rate (CRXR)\n",
254 				can_stats.current_rx_rate);
255 
256 		seq_putc(m, '\n');
257 
258 		seq_printf(m, " %8ld %% max match ratio (MRXMR)\n",
259 				can_stats.max_rx_match_ratio);
260 
261 		seq_printf(m, " %8ld frames/s max tx rate (MTXR)\n",
262 				can_stats.max_tx_rate);
263 		seq_printf(m, " %8ld frames/s max rx rate (MRXR)\n",
264 				can_stats.max_rx_rate);
265 
266 		seq_putc(m, '\n');
267 	}
268 
269 	seq_printf(m, " %8ld current receive list entries (CRCV)\n",
270 			can_pstats.rcv_entries);
271 	seq_printf(m, " %8ld maximum receive list entries (MRCV)\n",
272 			can_pstats.rcv_entries_max);
273 
274 	if (can_pstats.stats_reset)
275 		seq_printf(m, "\n %8ld statistic resets (STR)\n",
276 				can_pstats.stats_reset);
277 
278 	if (can_pstats.user_reset)
279 		seq_printf(m, " %8ld user statistic resets (USTR)\n",
280 				can_pstats.user_reset);
281 
282 	seq_putc(m, '\n');
283 	return 0;
284 }
285 
286 static int can_stats_proc_open(struct inode *inode, struct file *file)
287 {
288 	return single_open(file, can_stats_proc_show, NULL);
289 }
290 
291 static const struct file_operations can_stats_proc_fops = {
292 	.owner		= THIS_MODULE,
293 	.open		= can_stats_proc_open,
294 	.read		= seq_read,
295 	.llseek		= seq_lseek,
296 	.release	= single_release,
297 };
298 
299 static int can_reset_stats_proc_show(struct seq_file *m, void *v)
300 {
301 	user_reset = 1;
302 
303 	if (can_stattimer.function == can_stat_update) {
304 		seq_printf(m, "Scheduled statistic reset #%ld.\n",
305 				can_pstats.stats_reset + 1);
306 
307 	} else {
308 		if (can_stats.jiffies_init != jiffies)
309 			can_init_stats();
310 
311 		seq_printf(m, "Performed statistic reset #%ld.\n",
312 				can_pstats.stats_reset);
313 	}
314 	return 0;
315 }
316 
317 static int can_reset_stats_proc_open(struct inode *inode, struct file *file)
318 {
319 	return single_open(file, can_reset_stats_proc_show, NULL);
320 }
321 
322 static const struct file_operations can_reset_stats_proc_fops = {
323 	.owner		= THIS_MODULE,
324 	.open		= can_reset_stats_proc_open,
325 	.read		= seq_read,
326 	.llseek		= seq_lseek,
327 	.release	= single_release,
328 };
329 
330 static int can_version_proc_show(struct seq_file *m, void *v)
331 {
332 	seq_printf(m, "%s\n", CAN_VERSION_STRING);
333 	return 0;
334 }
335 
336 static int can_version_proc_open(struct inode *inode, struct file *file)
337 {
338 	return single_open(file, can_version_proc_show, NULL);
339 }
340 
341 static const struct file_operations can_version_proc_fops = {
342 	.owner		= THIS_MODULE,
343 	.open		= can_version_proc_open,
344 	.read		= seq_read,
345 	.llseek		= seq_lseek,
346 	.release	= single_release,
347 };
348 
349 static int can_rcvlist_proc_show(struct seq_file *m, void *v)
350 {
351 	/* double cast to prevent GCC warning */
352 	int idx = (int)(long)m->private;
353 	struct dev_rcv_lists *d;
354 	struct hlist_node *n;
355 
356 	seq_printf(m, "\nreceive list '%s':\n", rx_list_name[idx]);
357 
358 	rcu_read_lock();
359 	hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) {
360 
361 		if (!hlist_empty(&d->rx[idx])) {
362 			can_print_recv_banner(m);
363 			can_print_rcvlist(m, &d->rx[idx], d->dev);
364 		} else
365 			seq_printf(m, "  (%s: no entry)\n", DNAME(d->dev));
366 	}
367 	rcu_read_unlock();
368 
369 	seq_putc(m, '\n');
370 	return 0;
371 }
372 
373 static int can_rcvlist_proc_open(struct inode *inode, struct file *file)
374 {
375 	return single_open(file, can_rcvlist_proc_show, PDE(inode)->data);
376 }
377 
378 static const struct file_operations can_rcvlist_proc_fops = {
379 	.owner		= THIS_MODULE,
380 	.open		= can_rcvlist_proc_open,
381 	.read		= seq_read,
382 	.llseek		= seq_lseek,
383 	.release	= single_release,
384 };
385 
386 static int can_rcvlist_sff_proc_show(struct seq_file *m, void *v)
387 {
388 	struct dev_rcv_lists *d;
389 	struct hlist_node *n;
390 
391 	/* RX_SFF */
392 	seq_puts(m, "\nreceive list 'rx_sff':\n");
393 
394 	rcu_read_lock();
395 	hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) {
396 		int i, all_empty = 1;
397 		/* check wether at least one list is non-empty */
398 		for (i = 0; i < 0x800; i++)
399 			if (!hlist_empty(&d->rx_sff[i])) {
400 				all_empty = 0;
401 				break;
402 			}
403 
404 		if (!all_empty) {
405 			can_print_recv_banner(m);
406 			for (i = 0; i < 0x800; i++) {
407 				if (!hlist_empty(&d->rx_sff[i]))
408 					can_print_rcvlist(m, &d->rx_sff[i],
409 							  d->dev);
410 			}
411 		} else
412 			seq_printf(m, "  (%s: no entry)\n", DNAME(d->dev));
413 	}
414 	rcu_read_unlock();
415 
416 	seq_putc(m, '\n');
417 	return 0;
418 }
419 
420 static int can_rcvlist_sff_proc_open(struct inode *inode, struct file *file)
421 {
422 	return single_open(file, can_rcvlist_sff_proc_show, NULL);
423 }
424 
425 static const struct file_operations can_rcvlist_sff_proc_fops = {
426 	.owner		= THIS_MODULE,
427 	.open		= can_rcvlist_sff_proc_open,
428 	.read		= seq_read,
429 	.llseek		= seq_lseek,
430 	.release	= single_release,
431 };
432 
433 /*
434  * proc utility functions
435  */
436 
437 static void can_remove_proc_readentry(const char *name)
438 {
439 	if (can_dir)
440 		remove_proc_entry(name, can_dir);
441 }
442 
443 /*
444  * can_init_proc - create main CAN proc directory and procfs entries
445  */
446 void can_init_proc(void)
447 {
448 	/* create /proc/net/can directory */
449 	can_dir = proc_mkdir("can", init_net.proc_net);
450 
451 	if (!can_dir) {
452 		printk(KERN_INFO "can: failed to create /proc/net/can . "
453 		       "CONFIG_PROC_FS missing?\n");
454 		return;
455 	}
456 
457 	/* own procfs entries from the AF_CAN core */
458 	pde_version     = proc_create(CAN_PROC_VERSION, 0644, can_dir,
459 				      &can_version_proc_fops);
460 	pde_stats       = proc_create(CAN_PROC_STATS, 0644, can_dir,
461 				      &can_stats_proc_fops);
462 	pde_reset_stats = proc_create(CAN_PROC_RESET_STATS, 0644, can_dir,
463 				      &can_reset_stats_proc_fops);
464 	pde_rcvlist_err = proc_create_data(CAN_PROC_RCVLIST_ERR, 0644, can_dir,
465 					   &can_rcvlist_proc_fops, (void *)RX_ERR);
466 	pde_rcvlist_all = proc_create_data(CAN_PROC_RCVLIST_ALL, 0644, can_dir,
467 					   &can_rcvlist_proc_fops, (void *)RX_ALL);
468 	pde_rcvlist_fil = proc_create_data(CAN_PROC_RCVLIST_FIL, 0644, can_dir,
469 					   &can_rcvlist_proc_fops, (void *)RX_FIL);
470 	pde_rcvlist_inv = proc_create_data(CAN_PROC_RCVLIST_INV, 0644, can_dir,
471 					   &can_rcvlist_proc_fops, (void *)RX_INV);
472 	pde_rcvlist_eff = proc_create_data(CAN_PROC_RCVLIST_EFF, 0644, can_dir,
473 					   &can_rcvlist_proc_fops, (void *)RX_EFF);
474 	pde_rcvlist_sff = proc_create(CAN_PROC_RCVLIST_SFF, 0644, can_dir,
475 				      &can_rcvlist_sff_proc_fops);
476 }
477 
478 /*
479  * can_remove_proc - remove procfs entries and main CAN proc directory
480  */
481 void can_remove_proc(void)
482 {
483 	if (pde_version)
484 		can_remove_proc_readentry(CAN_PROC_VERSION);
485 
486 	if (pde_stats)
487 		can_remove_proc_readentry(CAN_PROC_STATS);
488 
489 	if (pde_reset_stats)
490 		can_remove_proc_readentry(CAN_PROC_RESET_STATS);
491 
492 	if (pde_rcvlist_err)
493 		can_remove_proc_readentry(CAN_PROC_RCVLIST_ERR);
494 
495 	if (pde_rcvlist_all)
496 		can_remove_proc_readentry(CAN_PROC_RCVLIST_ALL);
497 
498 	if (pde_rcvlist_fil)
499 		can_remove_proc_readentry(CAN_PROC_RCVLIST_FIL);
500 
501 	if (pde_rcvlist_inv)
502 		can_remove_proc_readentry(CAN_PROC_RCVLIST_INV);
503 
504 	if (pde_rcvlist_eff)
505 		can_remove_proc_readentry(CAN_PROC_RCVLIST_EFF);
506 
507 	if (pde_rcvlist_sff)
508 		can_remove_proc_readentry(CAN_PROC_RCVLIST_SFF);
509 
510 	if (can_dir)
511 		proc_net_remove(&init_net, "can");
512 }
513