xref: /openbmc/linux/net/can/proc.c (revision 7a2eb736)
1 // SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)
2 /*
3  * proc.c - procfs support for Protocol family CAN core module
4  *
5  * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of Volkswagen nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * Alternatively, provided that this notice is retained in full, this
21  * software may be distributed under the terms of the GNU General
22  * Public License ("GPL") version 2, in which case the provisions of the
23  * GPL apply INSTEAD OF those given above.
24  *
25  * The provided data structures and external interfaces from this code
26  * are not restricted to be used by modules with a GPL compatible license.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
32  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
33  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
38  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
39  * DAMAGE.
40  *
41  */
42 
43 #include <linux/module.h>
44 #include <linux/proc_fs.h>
45 #include <linux/list.h>
46 #include <linux/rcupdate.h>
47 #include <linux/if_arp.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 int user_reset;
67 
68 static const char rx_list_name[][8] = {
69 	[RX_ERR] = "rx_err",
70 	[RX_ALL] = "rx_all",
71 	[RX_FIL] = "rx_fil",
72 	[RX_INV] = "rx_inv",
73 };
74 
75 /*
76  * af_can statistics stuff
77  */
78 
79 static void can_init_stats(struct net *net)
80 {
81 	struct s_stats *can_stats = net->can.can_stats;
82 	struct s_pstats *can_pstats = net->can.can_pstats;
83 	/*
84 	 * This memset function is called from a timer context (when
85 	 * can_stattimer is active which is the default) OR in a process
86 	 * context (reading the proc_fs when can_stattimer is disabled).
87 	 */
88 	memset(can_stats, 0, sizeof(struct s_stats));
89 	can_stats->jiffies_init = jiffies;
90 
91 	can_pstats->stats_reset++;
92 
93 	if (user_reset) {
94 		user_reset = 0;
95 		can_pstats->user_reset++;
96 	}
97 }
98 
99 static unsigned long calc_rate(unsigned long oldjif, unsigned long newjif,
100 			       unsigned long count)
101 {
102 	unsigned long rate;
103 
104 	if (oldjif == newjif)
105 		return 0;
106 
107 	/* see can_stat_update() - this should NEVER happen! */
108 	if (count > (ULONG_MAX / HZ)) {
109 		printk(KERN_ERR "can: calc_rate: count exceeded! %ld\n",
110 		       count);
111 		return 99999999;
112 	}
113 
114 	rate = (count * HZ) / (newjif - oldjif);
115 
116 	return rate;
117 }
118 
119 void can_stat_update(struct timer_list *t)
120 {
121 	struct net *net = from_timer(net, t, can.can_stattimer);
122 	struct s_stats *can_stats = net->can.can_stats;
123 	unsigned long j = jiffies; /* snapshot */
124 
125 	/* restart counting in timer context on user request */
126 	if (user_reset)
127 		can_init_stats(net);
128 
129 	/* restart counting on jiffies overflow */
130 	if (j < can_stats->jiffies_init)
131 		can_init_stats(net);
132 
133 	/* prevent overflow in calc_rate() */
134 	if (can_stats->rx_frames > (ULONG_MAX / HZ))
135 		can_init_stats(net);
136 
137 	/* prevent overflow in calc_rate() */
138 	if (can_stats->tx_frames > (ULONG_MAX / HZ))
139 		can_init_stats(net);
140 
141 	/* matches overflow - very improbable */
142 	if (can_stats->matches > (ULONG_MAX / 100))
143 		can_init_stats(net);
144 
145 	/* calc total values */
146 	if (can_stats->rx_frames)
147 		can_stats->total_rx_match_ratio = (can_stats->matches * 100) /
148 			can_stats->rx_frames;
149 
150 	can_stats->total_tx_rate = calc_rate(can_stats->jiffies_init, j,
151 					    can_stats->tx_frames);
152 	can_stats->total_rx_rate = calc_rate(can_stats->jiffies_init, j,
153 					    can_stats->rx_frames);
154 
155 	/* calc current values */
156 	if (can_stats->rx_frames_delta)
157 		can_stats->current_rx_match_ratio =
158 			(can_stats->matches_delta * 100) /
159 			can_stats->rx_frames_delta;
160 
161 	can_stats->current_tx_rate = calc_rate(0, HZ, can_stats->tx_frames_delta);
162 	can_stats->current_rx_rate = calc_rate(0, HZ, can_stats->rx_frames_delta);
163 
164 	/* check / update maximum values */
165 	if (can_stats->max_tx_rate < can_stats->current_tx_rate)
166 		can_stats->max_tx_rate = can_stats->current_tx_rate;
167 
168 	if (can_stats->max_rx_rate < can_stats->current_rx_rate)
169 		can_stats->max_rx_rate = can_stats->current_rx_rate;
170 
171 	if (can_stats->max_rx_match_ratio < can_stats->current_rx_match_ratio)
172 		can_stats->max_rx_match_ratio = can_stats->current_rx_match_ratio;
173 
174 	/* clear values for 'current rate' calculation */
175 	can_stats->tx_frames_delta = 0;
176 	can_stats->rx_frames_delta = 0;
177 	can_stats->matches_delta   = 0;
178 
179 	/* restart timer (one second) */
180 	mod_timer(&net->can.can_stattimer, round_jiffies(jiffies + HZ));
181 }
182 
183 /*
184  * proc read functions
185  */
186 
187 static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list,
188 			      struct net_device *dev)
189 {
190 	struct receiver *r;
191 
192 	hlist_for_each_entry_rcu(r, rx_list, list) {
193 		char *fmt = (r->can_id & CAN_EFF_FLAG)?
194 			"   %-5s  %08x  %08x  %pK  %pK  %8ld  %s\n" :
195 			"   %-5s     %03x    %08x  %pK  %pK  %8ld  %s\n";
196 
197 		seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
198 				r->func, r->data, r->matches, r->ident);
199 	}
200 }
201 
202 static void can_print_recv_banner(struct seq_file *m)
203 {
204 	/*
205 	 *                  can1.  00000000  00000000  00000000
206 	 *                 .......          0  tp20
207 	 */
208 	seq_puts(m, "  device   can_id   can_mask  function"
209 			"  userdata   matches  ident\n");
210 }
211 
212 static int can_stats_proc_show(struct seq_file *m, void *v)
213 {
214 	struct net *net = m->private;
215 	struct s_stats *can_stats = net->can.can_stats;
216 	struct s_pstats *can_pstats = net->can.can_pstats;
217 
218 	seq_putc(m, '\n');
219 	seq_printf(m, " %8ld transmitted frames (TXF)\n", can_stats->tx_frames);
220 	seq_printf(m, " %8ld received frames (RXF)\n", can_stats->rx_frames);
221 	seq_printf(m, " %8ld matched frames (RXMF)\n", can_stats->matches);
222 
223 	seq_putc(m, '\n');
224 
225 	if (net->can.can_stattimer.function == can_stat_update) {
226 		seq_printf(m, " %8ld %% total match ratio (RXMR)\n",
227 				can_stats->total_rx_match_ratio);
228 
229 		seq_printf(m, " %8ld frames/s total tx rate (TXR)\n",
230 				can_stats->total_tx_rate);
231 		seq_printf(m, " %8ld frames/s total rx rate (RXR)\n",
232 				can_stats->total_rx_rate);
233 
234 		seq_putc(m, '\n');
235 
236 		seq_printf(m, " %8ld %% current match ratio (CRXMR)\n",
237 				can_stats->current_rx_match_ratio);
238 
239 		seq_printf(m, " %8ld frames/s current tx rate (CTXR)\n",
240 				can_stats->current_tx_rate);
241 		seq_printf(m, " %8ld frames/s current rx rate (CRXR)\n",
242 				can_stats->current_rx_rate);
243 
244 		seq_putc(m, '\n');
245 
246 		seq_printf(m, " %8ld %% max match ratio (MRXMR)\n",
247 				can_stats->max_rx_match_ratio);
248 
249 		seq_printf(m, " %8ld frames/s max tx rate (MTXR)\n",
250 				can_stats->max_tx_rate);
251 		seq_printf(m, " %8ld frames/s max rx rate (MRXR)\n",
252 				can_stats->max_rx_rate);
253 
254 		seq_putc(m, '\n');
255 	}
256 
257 	seq_printf(m, " %8ld current receive list entries (CRCV)\n",
258 			can_pstats->rcv_entries);
259 	seq_printf(m, " %8ld maximum receive list entries (MRCV)\n",
260 			can_pstats->rcv_entries_max);
261 
262 	if (can_pstats->stats_reset)
263 		seq_printf(m, "\n %8ld statistic resets (STR)\n",
264 				can_pstats->stats_reset);
265 
266 	if (can_pstats->user_reset)
267 		seq_printf(m, " %8ld user statistic resets (USTR)\n",
268 				can_pstats->user_reset);
269 
270 	seq_putc(m, '\n');
271 	return 0;
272 }
273 
274 static int can_reset_stats_proc_show(struct seq_file *m, void *v)
275 {
276 	struct net *net = m->private;
277 	struct s_pstats *can_pstats = net->can.can_pstats;
278 	struct s_stats *can_stats = net->can.can_stats;
279 
280 	user_reset = 1;
281 
282 	if (net->can.can_stattimer.function == can_stat_update) {
283 		seq_printf(m, "Scheduled statistic reset #%ld.\n",
284 				can_pstats->stats_reset + 1);
285 	} else {
286 		if (can_stats->jiffies_init != jiffies)
287 			can_init_stats(net);
288 
289 		seq_printf(m, "Performed statistic reset #%ld.\n",
290 				can_pstats->stats_reset);
291 	}
292 	return 0;
293 }
294 
295 static int can_version_proc_show(struct seq_file *m, void *v)
296 {
297 	seq_printf(m, "%s\n", CAN_VERSION_STRING);
298 	return 0;
299 }
300 
301 static inline void can_rcvlist_proc_show_one(struct seq_file *m, int idx,
302 					     struct net_device *dev,
303 					     struct can_dev_rcv_lists *d)
304 {
305 	if (!hlist_empty(&d->rx[idx])) {
306 		can_print_recv_banner(m);
307 		can_print_rcvlist(m, &d->rx[idx], dev);
308 	} else
309 		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
310 
311 }
312 
313 static int can_rcvlist_proc_show(struct seq_file *m, void *v)
314 {
315 	/* double cast to prevent GCC warning */
316 	int idx = (int)(long)PDE_DATA(m->file->f_inode);
317 	struct net_device *dev;
318 	struct can_dev_rcv_lists *d;
319 	struct net *net = m->private;
320 
321 	seq_printf(m, "\nreceive list '%s':\n", rx_list_name[idx]);
322 
323 	rcu_read_lock();
324 
325 	/* receive list for 'all' CAN devices (dev == NULL) */
326 	d = net->can.can_rx_alldev_list;
327 	can_rcvlist_proc_show_one(m, idx, NULL, d);
328 
329 	/* receive list for registered CAN devices */
330 	for_each_netdev_rcu(net, dev) {
331 		if (dev->type == ARPHRD_CAN && dev->ml_priv)
332 			can_rcvlist_proc_show_one(m, idx, dev, dev->ml_priv);
333 	}
334 
335 	rcu_read_unlock();
336 
337 	seq_putc(m, '\n');
338 	return 0;
339 }
340 
341 static inline void can_rcvlist_proc_show_array(struct seq_file *m,
342 					       struct net_device *dev,
343 					       struct hlist_head *rcv_array,
344 					       unsigned int rcv_array_sz)
345 {
346 	unsigned int i;
347 	int all_empty = 1;
348 
349 	/* check whether at least one list is non-empty */
350 	for (i = 0; i < rcv_array_sz; i++)
351 		if (!hlist_empty(&rcv_array[i])) {
352 			all_empty = 0;
353 			break;
354 		}
355 
356 	if (!all_empty) {
357 		can_print_recv_banner(m);
358 		for (i = 0; i < rcv_array_sz; i++) {
359 			if (!hlist_empty(&rcv_array[i]))
360 				can_print_rcvlist(m, &rcv_array[i], dev);
361 		}
362 	} else
363 		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
364 }
365 
366 static int can_rcvlist_sff_proc_show(struct seq_file *m, void *v)
367 {
368 	struct net_device *dev;
369 	struct can_dev_rcv_lists *d;
370 	struct net *net = m->private;
371 
372 	/* RX_SFF */
373 	seq_puts(m, "\nreceive list 'rx_sff':\n");
374 
375 	rcu_read_lock();
376 
377 	/* sff receive list for 'all' CAN devices (dev == NULL) */
378 	d = net->can.can_rx_alldev_list;
379 	can_rcvlist_proc_show_array(m, NULL, d->rx_sff, ARRAY_SIZE(d->rx_sff));
380 
381 	/* sff receive list for registered CAN devices */
382 	for_each_netdev_rcu(net, dev) {
383 		if (dev->type == ARPHRD_CAN && dev->ml_priv) {
384 			d = dev->ml_priv;
385 			can_rcvlist_proc_show_array(m, dev, d->rx_sff,
386 						    ARRAY_SIZE(d->rx_sff));
387 		}
388 	}
389 
390 	rcu_read_unlock();
391 
392 	seq_putc(m, '\n');
393 	return 0;
394 }
395 
396 static int can_rcvlist_eff_proc_show(struct seq_file *m, void *v)
397 {
398 	struct net_device *dev;
399 	struct can_dev_rcv_lists *d;
400 	struct net *net = m->private;
401 
402 	/* RX_EFF */
403 	seq_puts(m, "\nreceive list 'rx_eff':\n");
404 
405 	rcu_read_lock();
406 
407 	/* eff receive list for 'all' CAN devices (dev == NULL) */
408 	d = net->can.can_rx_alldev_list;
409 	can_rcvlist_proc_show_array(m, NULL, d->rx_eff, ARRAY_SIZE(d->rx_eff));
410 
411 	/* eff receive list for registered CAN devices */
412 	for_each_netdev_rcu(net, dev) {
413 		if (dev->type == ARPHRD_CAN && dev->ml_priv) {
414 			d = dev->ml_priv;
415 			can_rcvlist_proc_show_array(m, dev, d->rx_eff,
416 						    ARRAY_SIZE(d->rx_eff));
417 		}
418 	}
419 
420 	rcu_read_unlock();
421 
422 	seq_putc(m, '\n');
423 	return 0;
424 }
425 
426 /*
427  * can_init_proc - create main CAN proc directory and procfs entries
428  */
429 void can_init_proc(struct net *net)
430 {
431 	/* create /proc/net/can directory */
432 	net->can.proc_dir = proc_net_mkdir(net, "can", net->proc_net);
433 
434 	if (!net->can.proc_dir) {
435 		printk(KERN_INFO "can: failed to create /proc/net/can . "
436 			   "CONFIG_PROC_FS missing?\n");
437 		return;
438 	}
439 
440 	/* own procfs entries from the AF_CAN core */
441 	net->can.pde_version = proc_create_net_single(CAN_PROC_VERSION, 0644,
442 			net->can.proc_dir, can_version_proc_show, NULL);
443 	net->can.pde_stats = proc_create_net_single(CAN_PROC_STATS, 0644,
444 			net->can.proc_dir, can_stats_proc_show, NULL);
445 	net->can.pde_reset_stats = proc_create_net_single(CAN_PROC_RESET_STATS,
446 			0644, net->can.proc_dir, can_reset_stats_proc_show,
447 			NULL);
448 	net->can.pde_rcvlist_err = proc_create_net_single(CAN_PROC_RCVLIST_ERR,
449 			0644, net->can.proc_dir, can_rcvlist_proc_show,
450 			(void *)RX_ERR);
451 	net->can.pde_rcvlist_all = proc_create_net_single(CAN_PROC_RCVLIST_ALL,
452 			0644, net->can.proc_dir, can_rcvlist_proc_show,
453 			(void *)RX_ALL);
454 	net->can.pde_rcvlist_fil = proc_create_net_single(CAN_PROC_RCVLIST_FIL,
455 			0644, net->can.proc_dir, can_rcvlist_proc_show,
456 			(void *)RX_FIL);
457 	net->can.pde_rcvlist_inv = proc_create_net_single(CAN_PROC_RCVLIST_INV,
458 			0644, net->can.proc_dir, can_rcvlist_proc_show,
459 			(void *)RX_INV);
460 	net->can.pde_rcvlist_eff = proc_create_net_single(CAN_PROC_RCVLIST_EFF,
461 			0644, net->can.proc_dir, can_rcvlist_eff_proc_show, NULL);
462 	net->can.pde_rcvlist_sff = proc_create_net_single(CAN_PROC_RCVLIST_SFF,
463 			0644, net->can.proc_dir, can_rcvlist_sff_proc_show, NULL);
464 }
465 
466 /*
467  * can_remove_proc - remove procfs entries and main CAN proc directory
468  */
469 void can_remove_proc(struct net *net)
470 {
471 	if (net->can.pde_version)
472 		remove_proc_entry(CAN_PROC_VERSION, net->can.proc_dir);
473 
474 	if (net->can.pde_stats)
475 		remove_proc_entry(CAN_PROC_STATS, net->can.proc_dir);
476 
477 	if (net->can.pde_reset_stats)
478 		remove_proc_entry(CAN_PROC_RESET_STATS, net->can.proc_dir);
479 
480 	if (net->can.pde_rcvlist_err)
481 		remove_proc_entry(CAN_PROC_RCVLIST_ERR, net->can.proc_dir);
482 
483 	if (net->can.pde_rcvlist_all)
484 		remove_proc_entry(CAN_PROC_RCVLIST_ALL, net->can.proc_dir);
485 
486 	if (net->can.pde_rcvlist_fil)
487 		remove_proc_entry(CAN_PROC_RCVLIST_FIL, net->can.proc_dir);
488 
489 	if (net->can.pde_rcvlist_inv)
490 		remove_proc_entry(CAN_PROC_RCVLIST_INV, net->can.proc_dir);
491 
492 	if (net->can.pde_rcvlist_eff)
493 		remove_proc_entry(CAN_PROC_RCVLIST_EFF, net->can.proc_dir);
494 
495 	if (net->can.pde_rcvlist_sff)
496 		remove_proc_entry(CAN_PROC_RCVLIST_SFF, net->can.proc_dir);
497 
498 	if (net->can.proc_dir)
499 		remove_proc_entry("can", net->proc_net);
500 }
501