xref: /openbmc/linux/net/can/proc.c (revision e5bd61e8)
1 // SPDX-License-Identifier: (GPL-2.0 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_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 can_pkg_stats *pkg_stats = net->can.pkg_stats;
82 	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
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(pkg_stats, 0, sizeof(struct can_pkg_stats));
89 	pkg_stats->jiffies_init = jiffies;
90 
91 	rcv_lists_stats->stats_reset++;
92 
93 	if (user_reset) {
94 		user_reset = 0;
95 		rcv_lists_stats->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.stattimer);
122 	struct can_pkg_stats *pkg_stats = net->can.pkg_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 < pkg_stats->jiffies_init)
131 		can_init_stats(net);
132 
133 	/* prevent overflow in calc_rate() */
134 	if (pkg_stats->rx_frames > (ULONG_MAX / HZ))
135 		can_init_stats(net);
136 
137 	/* prevent overflow in calc_rate() */
138 	if (pkg_stats->tx_frames > (ULONG_MAX / HZ))
139 		can_init_stats(net);
140 
141 	/* matches overflow - very improbable */
142 	if (pkg_stats->matches > (ULONG_MAX / 100))
143 		can_init_stats(net);
144 
145 	/* calc total values */
146 	if (pkg_stats->rx_frames)
147 		pkg_stats->total_rx_match_ratio = (pkg_stats->matches * 100) /
148 			pkg_stats->rx_frames;
149 
150 	pkg_stats->total_tx_rate = calc_rate(pkg_stats->jiffies_init, j,
151 					    pkg_stats->tx_frames);
152 	pkg_stats->total_rx_rate = calc_rate(pkg_stats->jiffies_init, j,
153 					    pkg_stats->rx_frames);
154 
155 	/* calc current values */
156 	if (pkg_stats->rx_frames_delta)
157 		pkg_stats->current_rx_match_ratio =
158 			(pkg_stats->matches_delta * 100) /
159 			pkg_stats->rx_frames_delta;
160 
161 	pkg_stats->current_tx_rate = calc_rate(0, HZ, pkg_stats->tx_frames_delta);
162 	pkg_stats->current_rx_rate = calc_rate(0, HZ, pkg_stats->rx_frames_delta);
163 
164 	/* check / update maximum values */
165 	if (pkg_stats->max_tx_rate < pkg_stats->current_tx_rate)
166 		pkg_stats->max_tx_rate = pkg_stats->current_tx_rate;
167 
168 	if (pkg_stats->max_rx_rate < pkg_stats->current_rx_rate)
169 		pkg_stats->max_rx_rate = pkg_stats->current_rx_rate;
170 
171 	if (pkg_stats->max_rx_match_ratio < pkg_stats->current_rx_match_ratio)
172 		pkg_stats->max_rx_match_ratio = pkg_stats->current_rx_match_ratio;
173 
174 	/* clear values for 'current rate' calculation */
175 	pkg_stats->tx_frames_delta = 0;
176 	pkg_stats->rx_frames_delta = 0;
177 	pkg_stats->matches_delta   = 0;
178 
179 	/* restart timer (one second) */
180 	mod_timer(&net->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 	if (IS_ENABLED(CONFIG_64BIT))
209 		seq_puts(m, "  device   can_id   can_mask      function          userdata       matches  ident\n");
210 	else
211 		seq_puts(m, "  device   can_id   can_mask  function  userdata   matches  ident\n");
212 }
213 
214 static int can_stats_proc_show(struct seq_file *m, void *v)
215 {
216 	struct net *net = m->private;
217 	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
218 	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
219 
220 	seq_putc(m, '\n');
221 	seq_printf(m, " %8ld transmitted frames (TXF)\n", pkg_stats->tx_frames);
222 	seq_printf(m, " %8ld received frames (RXF)\n", pkg_stats->rx_frames);
223 	seq_printf(m, " %8ld matched frames (RXMF)\n", pkg_stats->matches);
224 
225 	seq_putc(m, '\n');
226 
227 	if (net->can.stattimer.function == can_stat_update) {
228 		seq_printf(m, " %8ld %% total match ratio (RXMR)\n",
229 				pkg_stats->total_rx_match_ratio);
230 
231 		seq_printf(m, " %8ld frames/s total tx rate (TXR)\n",
232 				pkg_stats->total_tx_rate);
233 		seq_printf(m, " %8ld frames/s total rx rate (RXR)\n",
234 				pkg_stats->total_rx_rate);
235 
236 		seq_putc(m, '\n');
237 
238 		seq_printf(m, " %8ld %% current match ratio (CRXMR)\n",
239 				pkg_stats->current_rx_match_ratio);
240 
241 		seq_printf(m, " %8ld frames/s current tx rate (CTXR)\n",
242 				pkg_stats->current_tx_rate);
243 		seq_printf(m, " %8ld frames/s current rx rate (CRXR)\n",
244 				pkg_stats->current_rx_rate);
245 
246 		seq_putc(m, '\n');
247 
248 		seq_printf(m, " %8ld %% max match ratio (MRXMR)\n",
249 				pkg_stats->max_rx_match_ratio);
250 
251 		seq_printf(m, " %8ld frames/s max tx rate (MTXR)\n",
252 				pkg_stats->max_tx_rate);
253 		seq_printf(m, " %8ld frames/s max rx rate (MRXR)\n",
254 				pkg_stats->max_rx_rate);
255 
256 		seq_putc(m, '\n');
257 	}
258 
259 	seq_printf(m, " %8ld current receive list entries (CRCV)\n",
260 			rcv_lists_stats->rcv_entries);
261 	seq_printf(m, " %8ld maximum receive list entries (MRCV)\n",
262 			rcv_lists_stats->rcv_entries_max);
263 
264 	if (rcv_lists_stats->stats_reset)
265 		seq_printf(m, "\n %8ld statistic resets (STR)\n",
266 				rcv_lists_stats->stats_reset);
267 
268 	if (rcv_lists_stats->user_reset)
269 		seq_printf(m, " %8ld user statistic resets (USTR)\n",
270 				rcv_lists_stats->user_reset);
271 
272 	seq_putc(m, '\n');
273 	return 0;
274 }
275 
276 static int can_reset_stats_proc_show(struct seq_file *m, void *v)
277 {
278 	struct net *net = m->private;
279 	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
280 	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
281 
282 	user_reset = 1;
283 
284 	if (net->can.stattimer.function == can_stat_update) {
285 		seq_printf(m, "Scheduled statistic reset #%ld.\n",
286 				rcv_lists_stats->stats_reset + 1);
287 	} else {
288 		if (pkg_stats->jiffies_init != jiffies)
289 			can_init_stats(net);
290 
291 		seq_printf(m, "Performed statistic reset #%ld.\n",
292 				rcv_lists_stats->stats_reset);
293 	}
294 	return 0;
295 }
296 
297 static inline void can_rcvlist_proc_show_one(struct seq_file *m, int idx,
298 					     struct net_device *dev,
299 					     struct can_dev_rcv_lists *dev_rcv_lists)
300 {
301 	if (!hlist_empty(&dev_rcv_lists->rx[idx])) {
302 		can_print_recv_banner(m);
303 		can_print_rcvlist(m, &dev_rcv_lists->rx[idx], dev);
304 	} else
305 		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
306 
307 }
308 
309 static int can_rcvlist_proc_show(struct seq_file *m, void *v)
310 {
311 	/* double cast to prevent GCC warning */
312 	int idx = (int)(long)PDE_DATA(m->file->f_inode);
313 	struct net_device *dev;
314 	struct can_dev_rcv_lists *dev_rcv_lists;
315 	struct net *net = m->private;
316 
317 	seq_printf(m, "\nreceive list '%s':\n", rx_list_name[idx]);
318 
319 	rcu_read_lock();
320 
321 	/* receive list for 'all' CAN devices (dev == NULL) */
322 	dev_rcv_lists = net->can.rx_alldev_list;
323 	can_rcvlist_proc_show_one(m, idx, NULL, dev_rcv_lists);
324 
325 	/* receive list for registered CAN devices */
326 	for_each_netdev_rcu(net, dev) {
327 		struct can_ml_priv *can_ml = can_get_ml_priv(dev);
328 
329 		if (can_ml)
330 			can_rcvlist_proc_show_one(m, idx, dev,
331 						  &can_ml->dev_rcv_lists);
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 *dev_rcv_lists;
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 	dev_rcv_lists = net->can.rx_alldev_list;
378 	can_rcvlist_proc_show_array(m, NULL, dev_rcv_lists->rx_sff,
379 				    ARRAY_SIZE(dev_rcv_lists->rx_sff));
380 
381 	/* sff receive list for registered CAN devices */
382 	for_each_netdev_rcu(net, dev) {
383 		struct can_ml_priv *can_ml = can_get_ml_priv(dev);
384 
385 		if (can_ml) {
386 			dev_rcv_lists = &can_ml->dev_rcv_lists;
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 		struct can_ml_priv *can_ml = can_get_ml_priv(dev);
417 
418 		if (can_ml) {
419 			dev_rcv_lists = &can_ml->dev_rcv_lists;
420 			can_rcvlist_proc_show_array(m, dev, dev_rcv_lists->rx_eff,
421 						    ARRAY_SIZE(dev_rcv_lists->rx_eff));
422 		}
423 	}
424 
425 	rcu_read_unlock();
426 
427 	seq_putc(m, '\n');
428 	return 0;
429 }
430 
431 /*
432  * can_init_proc - create main CAN proc directory and procfs entries
433  */
434 void can_init_proc(struct net *net)
435 {
436 	/* create /proc/net/can directory */
437 	net->can.proc_dir = proc_net_mkdir(net, "can", net->proc_net);
438 
439 	if (!net->can.proc_dir) {
440 		printk(KERN_INFO "can: failed to create /proc/net/can . "
441 			   "CONFIG_PROC_FS missing?\n");
442 		return;
443 	}
444 
445 	/* own procfs entries from the AF_CAN core */
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.proc_dir)
475 		return;
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 	remove_proc_entry("can", net->proc_net);
502 }
503