xref: /openbmc/linux/net/can/proc.c (revision f9a82c48)
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 int user_reset;
66 
67 static const char rx_list_name[][8] = {
68 	[RX_ERR] = "rx_err",
69 	[RX_ALL] = "rx_all",
70 	[RX_FIL] = "rx_fil",
71 	[RX_INV] = "rx_inv",
72 };
73 
74 /*
75  * af_can statistics stuff
76  */
77 
78 static void can_init_stats(struct net *net)
79 {
80 	struct s_stats *can_stats = net->can.can_stats;
81 	struct s_pstats *can_pstats = net->can.can_pstats;
82 	/*
83 	 * This memset function is called from a timer context (when
84 	 * can_stattimer is active which is the default) OR in a process
85 	 * context (reading the proc_fs when can_stattimer is disabled).
86 	 */
87 	memset(can_stats, 0, sizeof(struct s_stats));
88 	can_stats->jiffies_init = jiffies;
89 
90 	can_pstats->stats_reset++;
91 
92 	if (user_reset) {
93 		user_reset = 0;
94 		can_pstats->user_reset++;
95 	}
96 }
97 
98 static unsigned long calc_rate(unsigned long oldjif, unsigned long newjif,
99 			       unsigned long count)
100 {
101 	unsigned long rate;
102 
103 	if (oldjif == newjif)
104 		return 0;
105 
106 	/* see can_stat_update() - this should NEVER happen! */
107 	if (count > (ULONG_MAX / HZ)) {
108 		printk(KERN_ERR "can: calc_rate: count exceeded! %ld\n",
109 		       count);
110 		return 99999999;
111 	}
112 
113 	rate = (count * HZ) / (newjif - oldjif);
114 
115 	return rate;
116 }
117 
118 void can_stat_update(struct timer_list *t)
119 {
120 	struct net *net = from_timer(net, t, can.can_stattimer);
121 	struct s_stats *can_stats = net->can.can_stats;
122 	unsigned long j = jiffies; /* snapshot */
123 
124 	/* restart counting in timer context on user request */
125 	if (user_reset)
126 		can_init_stats(net);
127 
128 	/* restart counting on jiffies overflow */
129 	if (j < can_stats->jiffies_init)
130 		can_init_stats(net);
131 
132 	/* prevent overflow in calc_rate() */
133 	if (can_stats->rx_frames > (ULONG_MAX / HZ))
134 		can_init_stats(net);
135 
136 	/* prevent overflow in calc_rate() */
137 	if (can_stats->tx_frames > (ULONG_MAX / HZ))
138 		can_init_stats(net);
139 
140 	/* matches overflow - very improbable */
141 	if (can_stats->matches > (ULONG_MAX / 100))
142 		can_init_stats(net);
143 
144 	/* calc total values */
145 	if (can_stats->rx_frames)
146 		can_stats->total_rx_match_ratio = (can_stats->matches * 100) /
147 			can_stats->rx_frames;
148 
149 	can_stats->total_tx_rate = calc_rate(can_stats->jiffies_init, j,
150 					    can_stats->tx_frames);
151 	can_stats->total_rx_rate = calc_rate(can_stats->jiffies_init, j,
152 					    can_stats->rx_frames);
153 
154 	/* calc current values */
155 	if (can_stats->rx_frames_delta)
156 		can_stats->current_rx_match_ratio =
157 			(can_stats->matches_delta * 100) /
158 			can_stats->rx_frames_delta;
159 
160 	can_stats->current_tx_rate = calc_rate(0, HZ, can_stats->tx_frames_delta);
161 	can_stats->current_rx_rate = calc_rate(0, HZ, can_stats->rx_frames_delta);
162 
163 	/* check / update maximum values */
164 	if (can_stats->max_tx_rate < can_stats->current_tx_rate)
165 		can_stats->max_tx_rate = can_stats->current_tx_rate;
166 
167 	if (can_stats->max_rx_rate < can_stats->current_rx_rate)
168 		can_stats->max_rx_rate = can_stats->current_rx_rate;
169 
170 	if (can_stats->max_rx_match_ratio < can_stats->current_rx_match_ratio)
171 		can_stats->max_rx_match_ratio = can_stats->current_rx_match_ratio;
172 
173 	/* clear values for 'current rate' calculation */
174 	can_stats->tx_frames_delta = 0;
175 	can_stats->rx_frames_delta = 0;
176 	can_stats->matches_delta   = 0;
177 
178 	/* restart timer (one second) */
179 	mod_timer(&net->can.can_stattimer, round_jiffies(jiffies + HZ));
180 }
181 
182 /*
183  * proc read functions
184  */
185 
186 static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list,
187 			      struct net_device *dev)
188 {
189 	struct receiver *r;
190 
191 	hlist_for_each_entry_rcu(r, rx_list, list) {
192 		char *fmt = (r->can_id & CAN_EFF_FLAG)?
193 			"   %-5s  %08x  %08x  %pK  %pK  %8ld  %s\n" :
194 			"   %-5s     %03x    %08x  %pK  %pK  %8ld  %s\n";
195 
196 		seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
197 				r->func, r->data, r->matches, r->ident);
198 	}
199 }
200 
201 static void can_print_recv_banner(struct seq_file *m)
202 {
203 	/*
204 	 *                  can1.  00000000  00000000  00000000
205 	 *                 .......          0  tp20
206 	 */
207 	seq_puts(m, "  device   can_id   can_mask  function"
208 			"  userdata   matches  ident\n");
209 }
210 
211 static int can_stats_proc_show(struct seq_file *m, void *v)
212 {
213 	struct net *net = m->private;
214 	struct s_stats *can_stats = net->can.can_stats;
215 	struct s_pstats *can_pstats = net->can.can_pstats;
216 
217 	seq_putc(m, '\n');
218 	seq_printf(m, " %8ld transmitted frames (TXF)\n", can_stats->tx_frames);
219 	seq_printf(m, " %8ld received frames (RXF)\n", can_stats->rx_frames);
220 	seq_printf(m, " %8ld matched frames (RXMF)\n", can_stats->matches);
221 
222 	seq_putc(m, '\n');
223 
224 	if (net->can.can_stattimer.function == can_stat_update) {
225 		seq_printf(m, " %8ld %% total match ratio (RXMR)\n",
226 				can_stats->total_rx_match_ratio);
227 
228 		seq_printf(m, " %8ld frames/s total tx rate (TXR)\n",
229 				can_stats->total_tx_rate);
230 		seq_printf(m, " %8ld frames/s total rx rate (RXR)\n",
231 				can_stats->total_rx_rate);
232 
233 		seq_putc(m, '\n');
234 
235 		seq_printf(m, " %8ld %% current match ratio (CRXMR)\n",
236 				can_stats->current_rx_match_ratio);
237 
238 		seq_printf(m, " %8ld frames/s current tx rate (CTXR)\n",
239 				can_stats->current_tx_rate);
240 		seq_printf(m, " %8ld frames/s current rx rate (CRXR)\n",
241 				can_stats->current_rx_rate);
242 
243 		seq_putc(m, '\n');
244 
245 		seq_printf(m, " %8ld %% max match ratio (MRXMR)\n",
246 				can_stats->max_rx_match_ratio);
247 
248 		seq_printf(m, " %8ld frames/s max tx rate (MTXR)\n",
249 				can_stats->max_tx_rate);
250 		seq_printf(m, " %8ld frames/s max rx rate (MRXR)\n",
251 				can_stats->max_rx_rate);
252 
253 		seq_putc(m, '\n');
254 	}
255 
256 	seq_printf(m, " %8ld current receive list entries (CRCV)\n",
257 			can_pstats->rcv_entries);
258 	seq_printf(m, " %8ld maximum receive list entries (MRCV)\n",
259 			can_pstats->rcv_entries_max);
260 
261 	if (can_pstats->stats_reset)
262 		seq_printf(m, "\n %8ld statistic resets (STR)\n",
263 				can_pstats->stats_reset);
264 
265 	if (can_pstats->user_reset)
266 		seq_printf(m, " %8ld user statistic resets (USTR)\n",
267 				can_pstats->user_reset);
268 
269 	seq_putc(m, '\n');
270 	return 0;
271 }
272 
273 static int can_reset_stats_proc_show(struct seq_file *m, void *v)
274 {
275 	struct net *net = m->private;
276 	struct s_pstats *can_pstats = net->can.can_pstats;
277 	struct s_stats *can_stats = net->can.can_stats;
278 
279 	user_reset = 1;
280 
281 	if (net->can.can_stattimer.function == can_stat_update) {
282 		seq_printf(m, "Scheduled statistic reset #%ld.\n",
283 				can_pstats->stats_reset + 1);
284 	} else {
285 		if (can_stats->jiffies_init != jiffies)
286 			can_init_stats(net);
287 
288 		seq_printf(m, "Performed statistic reset #%ld.\n",
289 				can_pstats->stats_reset);
290 	}
291 	return 0;
292 }
293 
294 static int can_version_proc_show(struct seq_file *m, void *v)
295 {
296 	seq_printf(m, "%s\n", CAN_VERSION_STRING);
297 	return 0;
298 }
299 
300 static inline void can_rcvlist_proc_show_one(struct seq_file *m, int idx,
301 					     struct net_device *dev,
302 					     struct can_dev_rcv_lists *d)
303 {
304 	if (!hlist_empty(&d->rx[idx])) {
305 		can_print_recv_banner(m);
306 		can_print_rcvlist(m, &d->rx[idx], dev);
307 	} else
308 		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
309 
310 }
311 
312 static int can_rcvlist_proc_show(struct seq_file *m, void *v)
313 {
314 	/* double cast to prevent GCC warning */
315 	int idx = (int)(long)PDE_DATA(m->file->f_inode);
316 	struct net_device *dev;
317 	struct can_dev_rcv_lists *d;
318 	struct net *net = m->private;
319 
320 	seq_printf(m, "\nreceive list '%s':\n", rx_list_name[idx]);
321 
322 	rcu_read_lock();
323 
324 	/* receive list for 'all' CAN devices (dev == NULL) */
325 	d = net->can.can_rx_alldev_list;
326 	can_rcvlist_proc_show_one(m, idx, NULL, d);
327 
328 	/* receive list for registered CAN devices */
329 	for_each_netdev_rcu(net, dev) {
330 		if (dev->type == ARPHRD_CAN && dev->ml_priv)
331 			can_rcvlist_proc_show_one(m, idx, dev, dev->ml_priv);
332 	}
333 
334 	rcu_read_unlock();
335 
336 	seq_putc(m, '\n');
337 	return 0;
338 }
339 
340 static inline void can_rcvlist_proc_show_array(struct seq_file *m,
341 					       struct net_device *dev,
342 					       struct hlist_head *rcv_array,
343 					       unsigned int rcv_array_sz)
344 {
345 	unsigned int i;
346 	int all_empty = 1;
347 
348 	/* check whether at least one list is non-empty */
349 	for (i = 0; i < rcv_array_sz; i++)
350 		if (!hlist_empty(&rcv_array[i])) {
351 			all_empty = 0;
352 			break;
353 		}
354 
355 	if (!all_empty) {
356 		can_print_recv_banner(m);
357 		for (i = 0; i < rcv_array_sz; i++) {
358 			if (!hlist_empty(&rcv_array[i]))
359 				can_print_rcvlist(m, &rcv_array[i], dev);
360 		}
361 	} else
362 		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
363 }
364 
365 static int can_rcvlist_sff_proc_show(struct seq_file *m, void *v)
366 {
367 	struct net_device *dev;
368 	struct can_dev_rcv_lists *d;
369 	struct net *net = m->private;
370 
371 	/* RX_SFF */
372 	seq_puts(m, "\nreceive list 'rx_sff':\n");
373 
374 	rcu_read_lock();
375 
376 	/* sff receive list for 'all' CAN devices (dev == NULL) */
377 	d = net->can.can_rx_alldev_list;
378 	can_rcvlist_proc_show_array(m, NULL, d->rx_sff, ARRAY_SIZE(d->rx_sff));
379 
380 	/* sff receive list for registered CAN devices */
381 	for_each_netdev_rcu(net, dev) {
382 		if (dev->type == ARPHRD_CAN && dev->ml_priv) {
383 			d = dev->ml_priv;
384 			can_rcvlist_proc_show_array(m, dev, d->rx_sff,
385 						    ARRAY_SIZE(d->rx_sff));
386 		}
387 	}
388 
389 	rcu_read_unlock();
390 
391 	seq_putc(m, '\n');
392 	return 0;
393 }
394 
395 static int can_rcvlist_eff_proc_show(struct seq_file *m, void *v)
396 {
397 	struct net_device *dev;
398 	struct can_dev_rcv_lists *d;
399 	struct net *net = m->private;
400 
401 	/* RX_EFF */
402 	seq_puts(m, "\nreceive list 'rx_eff':\n");
403 
404 	rcu_read_lock();
405 
406 	/* eff receive list for 'all' CAN devices (dev == NULL) */
407 	d = net->can.can_rx_alldev_list;
408 	can_rcvlist_proc_show_array(m, NULL, d->rx_eff, ARRAY_SIZE(d->rx_eff));
409 
410 	/* eff receive list for registered CAN devices */
411 	for_each_netdev_rcu(net, dev) {
412 		if (dev->type == ARPHRD_CAN && dev->ml_priv) {
413 			d = dev->ml_priv;
414 			can_rcvlist_proc_show_array(m, dev, d->rx_eff,
415 						    ARRAY_SIZE(d->rx_eff));
416 		}
417 	}
418 
419 	rcu_read_unlock();
420 
421 	seq_putc(m, '\n');
422 	return 0;
423 }
424 
425 /*
426  * can_init_proc - create main CAN proc directory and procfs entries
427  */
428 void can_init_proc(struct net *net)
429 {
430 	/* create /proc/net/can directory */
431 	net->can.proc_dir = proc_net_mkdir(net, "can", net->proc_net);
432 
433 	if (!net->can.proc_dir) {
434 		printk(KERN_INFO "can: failed to create /proc/net/can . "
435 			   "CONFIG_PROC_FS missing?\n");
436 		return;
437 	}
438 
439 	/* own procfs entries from the AF_CAN core */
440 	net->can.pde_version = proc_create_net_single(CAN_PROC_VERSION, 0644,
441 			net->can.proc_dir, can_version_proc_show, NULL);
442 	net->can.pde_stats = proc_create_net_single(CAN_PROC_STATS, 0644,
443 			net->can.proc_dir, can_stats_proc_show, NULL);
444 	net->can.pde_reset_stats = proc_create_net_single(CAN_PROC_RESET_STATS,
445 			0644, net->can.proc_dir, can_reset_stats_proc_show,
446 			NULL);
447 	net->can.pde_rcvlist_err = proc_create_net_single(CAN_PROC_RCVLIST_ERR,
448 			0644, net->can.proc_dir, can_rcvlist_proc_show,
449 			(void *)RX_ERR);
450 	net->can.pde_rcvlist_all = proc_create_net_single(CAN_PROC_RCVLIST_ALL,
451 			0644, net->can.proc_dir, can_rcvlist_proc_show,
452 			(void *)RX_ALL);
453 	net->can.pde_rcvlist_fil = proc_create_net_single(CAN_PROC_RCVLIST_FIL,
454 			0644, net->can.proc_dir, can_rcvlist_proc_show,
455 			(void *)RX_FIL);
456 	net->can.pde_rcvlist_inv = proc_create_net_single(CAN_PROC_RCVLIST_INV,
457 			0644, net->can.proc_dir, can_rcvlist_proc_show,
458 			(void *)RX_INV);
459 	net->can.pde_rcvlist_eff = proc_create_net_single(CAN_PROC_RCVLIST_EFF,
460 			0644, net->can.proc_dir, can_rcvlist_eff_proc_show, NULL);
461 	net->can.pde_rcvlist_sff = proc_create_net_single(CAN_PROC_RCVLIST_SFF,
462 			0644, net->can.proc_dir, can_rcvlist_sff_proc_show, NULL);
463 }
464 
465 /*
466  * can_remove_proc - remove procfs entries and main CAN proc directory
467  */
468 void can_remove_proc(struct net *net)
469 {
470 	if (net->can.pde_version)
471 		remove_proc_entry(CAN_PROC_VERSION, net->can.proc_dir);
472 
473 	if (net->can.pde_stats)
474 		remove_proc_entry(CAN_PROC_STATS, net->can.proc_dir);
475 
476 	if (net->can.pde_reset_stats)
477 		remove_proc_entry(CAN_PROC_RESET_STATS, net->can.proc_dir);
478 
479 	if (net->can.pde_rcvlist_err)
480 		remove_proc_entry(CAN_PROC_RCVLIST_ERR, net->can.proc_dir);
481 
482 	if (net->can.pde_rcvlist_all)
483 		remove_proc_entry(CAN_PROC_RCVLIST_ALL, net->can.proc_dir);
484 
485 	if (net->can.pde_rcvlist_fil)
486 		remove_proc_entry(CAN_PROC_RCVLIST_FIL, net->can.proc_dir);
487 
488 	if (net->can.pde_rcvlist_inv)
489 		remove_proc_entry(CAN_PROC_RCVLIST_INV, net->can.proc_dir);
490 
491 	if (net->can.pde_rcvlist_eff)
492 		remove_proc_entry(CAN_PROC_RCVLIST_EFF, net->can.proc_dir);
493 
494 	if (net->can.pde_rcvlist_sff)
495 		remove_proc_entry(CAN_PROC_RCVLIST_SFF, net->can.proc_dir);
496 
497 	if (net->can.proc_dir)
498 		remove_proc_entry("can", net->proc_net);
499 }
500