xref: /linux/net/can/proc.c (revision ca64d84e93762f4e587e040a44ad9f6089afc777)
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/can-ml.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 int user_reset;
68 
69 static const char rx_list_name[][8] = {
70 	[RX_ERR] = "rx_err",
71 	[RX_ALL] = "rx_all",
72 	[RX_FIL] = "rx_fil",
73 	[RX_INV] = "rx_inv",
74 };
75 
76 /*
77  * af_can statistics stuff
78  */
79 
80 static void can_init_stats(struct net *net)
81 {
82 	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
83 	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
84 	/*
85 	 * This memset function is called from a timer context (when
86 	 * can_stattimer is active which is the default) OR in a process
87 	 * context (reading the proc_fs when can_stattimer is disabled).
88 	 */
89 	memset(pkg_stats, 0, sizeof(struct can_pkg_stats));
90 	pkg_stats->jiffies_init = jiffies;
91 
92 	rcv_lists_stats->stats_reset++;
93 
94 	if (user_reset) {
95 		user_reset = 0;
96 		rcv_lists_stats->user_reset++;
97 	}
98 }
99 
100 static unsigned long calc_rate(unsigned long oldjif, unsigned long newjif,
101 			       unsigned long count)
102 {
103 	unsigned long rate;
104 
105 	if (oldjif == newjif)
106 		return 0;
107 
108 	/* see can_stat_update() - this should NEVER happen! */
109 	if (count > (ULONG_MAX / HZ)) {
110 		printk(KERN_ERR "can: calc_rate: count exceeded! %ld\n",
111 		       count);
112 		return 99999999;
113 	}
114 
115 	rate = (count * HZ) / (newjif - oldjif);
116 
117 	return rate;
118 }
119 
120 void can_stat_update(struct timer_list *t)
121 {
122 	struct net *net = from_timer(net, t, can.stattimer);
123 	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
124 	unsigned long j = jiffies; /* snapshot */
125 
126 	/* restart counting in timer context on user request */
127 	if (user_reset)
128 		can_init_stats(net);
129 
130 	/* restart counting on jiffies overflow */
131 	if (j < pkg_stats->jiffies_init)
132 		can_init_stats(net);
133 
134 	/* prevent overflow in calc_rate() */
135 	if (pkg_stats->rx_frames > (ULONG_MAX / HZ))
136 		can_init_stats(net);
137 
138 	/* prevent overflow in calc_rate() */
139 	if (pkg_stats->tx_frames > (ULONG_MAX / HZ))
140 		can_init_stats(net);
141 
142 	/* matches overflow - very improbable */
143 	if (pkg_stats->matches > (ULONG_MAX / 100))
144 		can_init_stats(net);
145 
146 	/* calc total values */
147 	if (pkg_stats->rx_frames)
148 		pkg_stats->total_rx_match_ratio = (pkg_stats->matches * 100) /
149 			pkg_stats->rx_frames;
150 
151 	pkg_stats->total_tx_rate = calc_rate(pkg_stats->jiffies_init, j,
152 					    pkg_stats->tx_frames);
153 	pkg_stats->total_rx_rate = calc_rate(pkg_stats->jiffies_init, j,
154 					    pkg_stats->rx_frames);
155 
156 	/* calc current values */
157 	if (pkg_stats->rx_frames_delta)
158 		pkg_stats->current_rx_match_ratio =
159 			(pkg_stats->matches_delta * 100) /
160 			pkg_stats->rx_frames_delta;
161 
162 	pkg_stats->current_tx_rate = calc_rate(0, HZ, pkg_stats->tx_frames_delta);
163 	pkg_stats->current_rx_rate = calc_rate(0, HZ, pkg_stats->rx_frames_delta);
164 
165 	/* check / update maximum values */
166 	if (pkg_stats->max_tx_rate < pkg_stats->current_tx_rate)
167 		pkg_stats->max_tx_rate = pkg_stats->current_tx_rate;
168 
169 	if (pkg_stats->max_rx_rate < pkg_stats->current_rx_rate)
170 		pkg_stats->max_rx_rate = pkg_stats->current_rx_rate;
171 
172 	if (pkg_stats->max_rx_match_ratio < pkg_stats->current_rx_match_ratio)
173 		pkg_stats->max_rx_match_ratio = pkg_stats->current_rx_match_ratio;
174 
175 	/* clear values for 'current rate' calculation */
176 	pkg_stats->tx_frames_delta = 0;
177 	pkg_stats->rx_frames_delta = 0;
178 	pkg_stats->matches_delta   = 0;
179 
180 	/* restart timer (one second) */
181 	mod_timer(&net->can.stattimer, round_jiffies(jiffies + HZ));
182 }
183 
184 /*
185  * proc read functions
186  */
187 
188 static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list,
189 			      struct net_device *dev)
190 {
191 	struct receiver *r;
192 
193 	hlist_for_each_entry_rcu(r, rx_list, list) {
194 		char *fmt = (r->can_id & CAN_EFF_FLAG)?
195 			"   %-5s  %08x  %08x  %pK  %pK  %8ld  %s\n" :
196 			"   %-5s     %03x    %08x  %pK  %pK  %8ld  %s\n";
197 
198 		seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
199 				r->func, r->data, r->matches, r->ident);
200 	}
201 }
202 
203 static void can_print_recv_banner(struct seq_file *m)
204 {
205 	/*
206 	 *                  can1.  00000000  00000000  00000000
207 	 *                 .......          0  tp20
208 	 */
209 	seq_puts(m, "  device   can_id   can_mask  function"
210 			"  userdata   matches  ident\n");
211 }
212 
213 static int can_stats_proc_show(struct seq_file *m, void *v)
214 {
215 	struct net *net = m->private;
216 	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
217 	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
218 
219 	seq_putc(m, '\n');
220 	seq_printf(m, " %8ld transmitted frames (TXF)\n", pkg_stats->tx_frames);
221 	seq_printf(m, " %8ld received frames (RXF)\n", pkg_stats->rx_frames);
222 	seq_printf(m, " %8ld matched frames (RXMF)\n", pkg_stats->matches);
223 
224 	seq_putc(m, '\n');
225 
226 	if (net->can.stattimer.function == can_stat_update) {
227 		seq_printf(m, " %8ld %% total match ratio (RXMR)\n",
228 				pkg_stats->total_rx_match_ratio);
229 
230 		seq_printf(m, " %8ld frames/s total tx rate (TXR)\n",
231 				pkg_stats->total_tx_rate);
232 		seq_printf(m, " %8ld frames/s total rx rate (RXR)\n",
233 				pkg_stats->total_rx_rate);
234 
235 		seq_putc(m, '\n');
236 
237 		seq_printf(m, " %8ld %% current match ratio (CRXMR)\n",
238 				pkg_stats->current_rx_match_ratio);
239 
240 		seq_printf(m, " %8ld frames/s current tx rate (CTXR)\n",
241 				pkg_stats->current_tx_rate);
242 		seq_printf(m, " %8ld frames/s current rx rate (CRXR)\n",
243 				pkg_stats->current_rx_rate);
244 
245 		seq_putc(m, '\n');
246 
247 		seq_printf(m, " %8ld %% max match ratio (MRXMR)\n",
248 				pkg_stats->max_rx_match_ratio);
249 
250 		seq_printf(m, " %8ld frames/s max tx rate (MTXR)\n",
251 				pkg_stats->max_tx_rate);
252 		seq_printf(m, " %8ld frames/s max rx rate (MRXR)\n",
253 				pkg_stats->max_rx_rate);
254 
255 		seq_putc(m, '\n');
256 	}
257 
258 	seq_printf(m, " %8ld current receive list entries (CRCV)\n",
259 			rcv_lists_stats->rcv_entries);
260 	seq_printf(m, " %8ld maximum receive list entries (MRCV)\n",
261 			rcv_lists_stats->rcv_entries_max);
262 
263 	if (rcv_lists_stats->stats_reset)
264 		seq_printf(m, "\n %8ld statistic resets (STR)\n",
265 				rcv_lists_stats->stats_reset);
266 
267 	if (rcv_lists_stats->user_reset)
268 		seq_printf(m, " %8ld user statistic resets (USTR)\n",
269 				rcv_lists_stats->user_reset);
270 
271 	seq_putc(m, '\n');
272 	return 0;
273 }
274 
275 static int can_reset_stats_proc_show(struct seq_file *m, void *v)
276 {
277 	struct net *net = m->private;
278 	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
279 	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
280 
281 	user_reset = 1;
282 
283 	if (net->can.stattimer.function == can_stat_update) {
284 		seq_printf(m, "Scheduled statistic reset #%ld.\n",
285 				rcv_lists_stats->stats_reset + 1);
286 	} else {
287 		if (pkg_stats->jiffies_init != jiffies)
288 			can_init_stats(net);
289 
290 		seq_printf(m, "Performed statistic reset #%ld.\n",
291 				rcv_lists_stats->stats_reset);
292 	}
293 	return 0;
294 }
295 
296 static int can_version_proc_show(struct seq_file *m, void *v)
297 {
298 	seq_printf(m, "%s\n", CAN_VERSION_STRING);
299 	return 0;
300 }
301 
302 static inline void can_rcvlist_proc_show_one(struct seq_file *m, int idx,
303 					     struct net_device *dev,
304 					     struct can_dev_rcv_lists *dev_rcv_lists)
305 {
306 	if (!hlist_empty(&dev_rcv_lists->rx[idx])) {
307 		can_print_recv_banner(m);
308 		can_print_rcvlist(m, &dev_rcv_lists->rx[idx], dev);
309 	} else
310 		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
311 
312 }
313 
314 static int can_rcvlist_proc_show(struct seq_file *m, void *v)
315 {
316 	/* double cast to prevent GCC warning */
317 	int idx = (int)(long)PDE_DATA(m->file->f_inode);
318 	struct net_device *dev;
319 	struct can_dev_rcv_lists *dev_rcv_lists;
320 	struct net *net = m->private;
321 
322 	seq_printf(m, "\nreceive list '%s':\n", rx_list_name[idx]);
323 
324 	rcu_read_lock();
325 
326 	/* receive list for 'all' CAN devices (dev == NULL) */
327 	dev_rcv_lists = net->can.rx_alldev_list;
328 	can_rcvlist_proc_show_one(m, idx, NULL, dev_rcv_lists);
329 
330 	/* receive list for registered CAN devices */
331 	for_each_netdev_rcu(net, dev) {
332 		if (dev->type == ARPHRD_CAN && dev->ml_priv)
333 			can_rcvlist_proc_show_one(m, idx, dev, dev->ml_priv);
334 	}
335 
336 	rcu_read_unlock();
337 
338 	seq_putc(m, '\n');
339 	return 0;
340 }
341 
342 static inline void can_rcvlist_proc_show_array(struct seq_file *m,
343 					       struct net_device *dev,
344 					       struct hlist_head *rcv_array,
345 					       unsigned int rcv_array_sz)
346 {
347 	unsigned int i;
348 	int all_empty = 1;
349 
350 	/* check whether at least one list is non-empty */
351 	for (i = 0; i < rcv_array_sz; i++)
352 		if (!hlist_empty(&rcv_array[i])) {
353 			all_empty = 0;
354 			break;
355 		}
356 
357 	if (!all_empty) {
358 		can_print_recv_banner(m);
359 		for (i = 0; i < rcv_array_sz; i++) {
360 			if (!hlist_empty(&rcv_array[i]))
361 				can_print_rcvlist(m, &rcv_array[i], dev);
362 		}
363 	} else
364 		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
365 }
366 
367 static int can_rcvlist_sff_proc_show(struct seq_file *m, void *v)
368 {
369 	struct net_device *dev;
370 	struct can_dev_rcv_lists *dev_rcv_lists;
371 	struct net *net = m->private;
372 
373 	/* RX_SFF */
374 	seq_puts(m, "\nreceive list 'rx_sff':\n");
375 
376 	rcu_read_lock();
377 
378 	/* sff receive list for 'all' CAN devices (dev == NULL) */
379 	dev_rcv_lists = net->can.rx_alldev_list;
380 	can_rcvlist_proc_show_array(m, NULL, dev_rcv_lists->rx_sff,
381 				    ARRAY_SIZE(dev_rcv_lists->rx_sff));
382 
383 	/* sff receive list for registered CAN devices */
384 	for_each_netdev_rcu(net, dev) {
385 		if (dev->type == ARPHRD_CAN && dev->ml_priv) {
386 			dev_rcv_lists = dev->ml_priv;
387 			can_rcvlist_proc_show_array(m, dev, dev_rcv_lists->rx_sff,
388 						    ARRAY_SIZE(dev_rcv_lists->rx_sff));
389 		}
390 	}
391 
392 	rcu_read_unlock();
393 
394 	seq_putc(m, '\n');
395 	return 0;
396 }
397 
398 static int can_rcvlist_eff_proc_show(struct seq_file *m, void *v)
399 {
400 	struct net_device *dev;
401 	struct can_dev_rcv_lists *dev_rcv_lists;
402 	struct net *net = m->private;
403 
404 	/* RX_EFF */
405 	seq_puts(m, "\nreceive list 'rx_eff':\n");
406 
407 	rcu_read_lock();
408 
409 	/* eff receive list for 'all' CAN devices (dev == NULL) */
410 	dev_rcv_lists = net->can.rx_alldev_list;
411 	can_rcvlist_proc_show_array(m, NULL, dev_rcv_lists->rx_eff,
412 				    ARRAY_SIZE(dev_rcv_lists->rx_eff));
413 
414 	/* eff receive list for registered CAN devices */
415 	for_each_netdev_rcu(net, dev) {
416 		if (dev->type == ARPHRD_CAN && dev->ml_priv) {
417 			dev_rcv_lists = dev->ml_priv;
418 			can_rcvlist_proc_show_array(m, dev, dev_rcv_lists->rx_eff,
419 						    ARRAY_SIZE(dev_rcv_lists->rx_eff));
420 		}
421 	}
422 
423 	rcu_read_unlock();
424 
425 	seq_putc(m, '\n');
426 	return 0;
427 }
428 
429 /*
430  * can_init_proc - create main CAN proc directory and procfs entries
431  */
432 void can_init_proc(struct net *net)
433 {
434 	/* create /proc/net/can directory */
435 	net->can.proc_dir = proc_net_mkdir(net, "can", net->proc_net);
436 
437 	if (!net->can.proc_dir) {
438 		printk(KERN_INFO "can: failed to create /proc/net/can . "
439 			   "CONFIG_PROC_FS missing?\n");
440 		return;
441 	}
442 
443 	/* own procfs entries from the AF_CAN core */
444 	net->can.pde_version = proc_create_net_single(CAN_PROC_VERSION, 0644,
445 			net->can.proc_dir, can_version_proc_show, NULL);
446 	net->can.pde_stats = proc_create_net_single(CAN_PROC_STATS, 0644,
447 			net->can.proc_dir, can_stats_proc_show, NULL);
448 	net->can.pde_reset_stats = proc_create_net_single(CAN_PROC_RESET_STATS,
449 			0644, net->can.proc_dir, can_reset_stats_proc_show,
450 			NULL);
451 	net->can.pde_rcvlist_err = proc_create_net_single(CAN_PROC_RCVLIST_ERR,
452 			0644, net->can.proc_dir, can_rcvlist_proc_show,
453 			(void *)RX_ERR);
454 	net->can.pde_rcvlist_all = proc_create_net_single(CAN_PROC_RCVLIST_ALL,
455 			0644, net->can.proc_dir, can_rcvlist_proc_show,
456 			(void *)RX_ALL);
457 	net->can.pde_rcvlist_fil = proc_create_net_single(CAN_PROC_RCVLIST_FIL,
458 			0644, net->can.proc_dir, can_rcvlist_proc_show,
459 			(void *)RX_FIL);
460 	net->can.pde_rcvlist_inv = proc_create_net_single(CAN_PROC_RCVLIST_INV,
461 			0644, net->can.proc_dir, can_rcvlist_proc_show,
462 			(void *)RX_INV);
463 	net->can.pde_rcvlist_eff = proc_create_net_single(CAN_PROC_RCVLIST_EFF,
464 			0644, net->can.proc_dir, can_rcvlist_eff_proc_show, NULL);
465 	net->can.pde_rcvlist_sff = proc_create_net_single(CAN_PROC_RCVLIST_SFF,
466 			0644, net->can.proc_dir, can_rcvlist_sff_proc_show, NULL);
467 }
468 
469 /*
470  * can_remove_proc - remove procfs entries and main CAN proc directory
471  */
472 void can_remove_proc(struct net *net)
473 {
474 	if (net->can.pde_version)
475 		remove_proc_entry(CAN_PROC_VERSION, net->can.proc_dir);
476 
477 	if (net->can.pde_stats)
478 		remove_proc_entry(CAN_PROC_STATS, net->can.proc_dir);
479 
480 	if (net->can.pde_reset_stats)
481 		remove_proc_entry(CAN_PROC_RESET_STATS, net->can.proc_dir);
482 
483 	if (net->can.pde_rcvlist_err)
484 		remove_proc_entry(CAN_PROC_RCVLIST_ERR, net->can.proc_dir);
485 
486 	if (net->can.pde_rcvlist_all)
487 		remove_proc_entry(CAN_PROC_RCVLIST_ALL, net->can.proc_dir);
488 
489 	if (net->can.pde_rcvlist_fil)
490 		remove_proc_entry(CAN_PROC_RCVLIST_FIL, net->can.proc_dir);
491 
492 	if (net->can.pde_rcvlist_inv)
493 		remove_proc_entry(CAN_PROC_RCVLIST_INV, net->can.proc_dir);
494 
495 	if (net->can.pde_rcvlist_eff)
496 		remove_proc_entry(CAN_PROC_RCVLIST_EFF, net->can.proc_dir);
497 
498 	if (net->can.pde_rcvlist_sff)
499 		remove_proc_entry(CAN_PROC_RCVLIST_SFF, net->can.proc_dir);
500 
501 	if (net->can.proc_dir)
502 		remove_proc_entry("can", net->proc_net);
503 }
504