xref: /kernel/linux/linux-5.10/net/can/proc.c (revision 8c2ecf20)
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
66static int user_reset;
67
68static 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
79static 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
99static 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
119void 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
187static 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
202static 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
212static int can_stats_proc_show(struct seq_file *m, void *v)
213{
214	struct net *net = m->private;
215	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
216	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
217
218	seq_putc(m, '\n');
219	seq_printf(m, " %8ld transmitted frames (TXF)\n", pkg_stats->tx_frames);
220	seq_printf(m, " %8ld received frames (RXF)\n", pkg_stats->rx_frames);
221	seq_printf(m, " %8ld matched frames (RXMF)\n", pkg_stats->matches);
222
223	seq_putc(m, '\n');
224
225	if (net->can.stattimer.function == can_stat_update) {
226		seq_printf(m, " %8ld %% total match ratio (RXMR)\n",
227				pkg_stats->total_rx_match_ratio);
228
229		seq_printf(m, " %8ld frames/s total tx rate (TXR)\n",
230				pkg_stats->total_tx_rate);
231		seq_printf(m, " %8ld frames/s total rx rate (RXR)\n",
232				pkg_stats->total_rx_rate);
233
234		seq_putc(m, '\n');
235
236		seq_printf(m, " %8ld %% current match ratio (CRXMR)\n",
237				pkg_stats->current_rx_match_ratio);
238
239		seq_printf(m, " %8ld frames/s current tx rate (CTXR)\n",
240				pkg_stats->current_tx_rate);
241		seq_printf(m, " %8ld frames/s current rx rate (CRXR)\n",
242				pkg_stats->current_rx_rate);
243
244		seq_putc(m, '\n');
245
246		seq_printf(m, " %8ld %% max match ratio (MRXMR)\n",
247				pkg_stats->max_rx_match_ratio);
248
249		seq_printf(m, " %8ld frames/s max tx rate (MTXR)\n",
250				pkg_stats->max_tx_rate);
251		seq_printf(m, " %8ld frames/s max rx rate (MRXR)\n",
252				pkg_stats->max_rx_rate);
253
254		seq_putc(m, '\n');
255	}
256
257	seq_printf(m, " %8ld current receive list entries (CRCV)\n",
258			rcv_lists_stats->rcv_entries);
259	seq_printf(m, " %8ld maximum receive list entries (MRCV)\n",
260			rcv_lists_stats->rcv_entries_max);
261
262	if (rcv_lists_stats->stats_reset)
263		seq_printf(m, "\n %8ld statistic resets (STR)\n",
264				rcv_lists_stats->stats_reset);
265
266	if (rcv_lists_stats->user_reset)
267		seq_printf(m, " %8ld user statistic resets (USTR)\n",
268				rcv_lists_stats->user_reset);
269
270	seq_putc(m, '\n');
271	return 0;
272}
273
274static int can_reset_stats_proc_show(struct seq_file *m, void *v)
275{
276	struct net *net = m->private;
277	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
278	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
279
280	user_reset = 1;
281
282	if (net->can.stattimer.function == can_stat_update) {
283		seq_printf(m, "Scheduled statistic reset #%ld.\n",
284				rcv_lists_stats->stats_reset + 1);
285	} else {
286		if (pkg_stats->jiffies_init != jiffies)
287			can_init_stats(net);
288
289		seq_printf(m, "Performed statistic reset #%ld.\n",
290				rcv_lists_stats->stats_reset);
291	}
292	return 0;
293}
294
295static inline void can_rcvlist_proc_show_one(struct seq_file *m, int idx,
296					     struct net_device *dev,
297					     struct can_dev_rcv_lists *dev_rcv_lists)
298{
299	if (!hlist_empty(&dev_rcv_lists->rx[idx])) {
300		can_print_recv_banner(m);
301		can_print_rcvlist(m, &dev_rcv_lists->rx[idx], dev);
302	} else
303		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
304
305}
306
307static int can_rcvlist_proc_show(struct seq_file *m, void *v)
308{
309	/* double cast to prevent GCC warning */
310	int idx = (int)(long)PDE_DATA(m->file->f_inode);
311	struct net_device *dev;
312	struct can_dev_rcv_lists *dev_rcv_lists;
313	struct net *net = m->private;
314
315	seq_printf(m, "\nreceive list '%s':\n", rx_list_name[idx]);
316
317	rcu_read_lock();
318
319	/* receive list for 'all' CAN devices (dev == NULL) */
320	dev_rcv_lists = net->can.rx_alldev_list;
321	can_rcvlist_proc_show_one(m, idx, NULL, dev_rcv_lists);
322
323	/* receive list for registered CAN devices */
324	for_each_netdev_rcu(net, dev) {
325		struct can_ml_priv *can_ml = can_get_ml_priv(dev);
326
327		if (can_ml)
328			can_rcvlist_proc_show_one(m, idx, dev,
329						  &can_ml->dev_rcv_lists);
330	}
331
332	rcu_read_unlock();
333
334	seq_putc(m, '\n');
335	return 0;
336}
337
338static inline void can_rcvlist_proc_show_array(struct seq_file *m,
339					       struct net_device *dev,
340					       struct hlist_head *rcv_array,
341					       unsigned int rcv_array_sz)
342{
343	unsigned int i;
344	int all_empty = 1;
345
346	/* check whether at least one list is non-empty */
347	for (i = 0; i < rcv_array_sz; i++)
348		if (!hlist_empty(&rcv_array[i])) {
349			all_empty = 0;
350			break;
351		}
352
353	if (!all_empty) {
354		can_print_recv_banner(m);
355		for (i = 0; i < rcv_array_sz; i++) {
356			if (!hlist_empty(&rcv_array[i]))
357				can_print_rcvlist(m, &rcv_array[i], dev);
358		}
359	} else
360		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
361}
362
363static int can_rcvlist_sff_proc_show(struct seq_file *m, void *v)
364{
365	struct net_device *dev;
366	struct can_dev_rcv_lists *dev_rcv_lists;
367	struct net *net = m->private;
368
369	/* RX_SFF */
370	seq_puts(m, "\nreceive list 'rx_sff':\n");
371
372	rcu_read_lock();
373
374	/* sff receive list for 'all' CAN devices (dev == NULL) */
375	dev_rcv_lists = net->can.rx_alldev_list;
376	can_rcvlist_proc_show_array(m, NULL, dev_rcv_lists->rx_sff,
377				    ARRAY_SIZE(dev_rcv_lists->rx_sff));
378
379	/* sff receive list for registered CAN devices */
380	for_each_netdev_rcu(net, dev) {
381		struct can_ml_priv *can_ml = can_get_ml_priv(dev);
382
383		if (can_ml) {
384			dev_rcv_lists = &can_ml->dev_rcv_lists;
385			can_rcvlist_proc_show_array(m, dev, dev_rcv_lists->rx_sff,
386						    ARRAY_SIZE(dev_rcv_lists->rx_sff));
387		}
388	}
389
390	rcu_read_unlock();
391
392	seq_putc(m, '\n');
393	return 0;
394}
395
396static int can_rcvlist_eff_proc_show(struct seq_file *m, void *v)
397{
398	struct net_device *dev;
399	struct can_dev_rcv_lists *dev_rcv_lists;
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	dev_rcv_lists = net->can.rx_alldev_list;
409	can_rcvlist_proc_show_array(m, NULL, dev_rcv_lists->rx_eff,
410				    ARRAY_SIZE(dev_rcv_lists->rx_eff));
411
412	/* eff receive list for registered CAN devices */
413	for_each_netdev_rcu(net, dev) {
414		struct can_ml_priv *can_ml = can_get_ml_priv(dev);
415
416		if (can_ml) {
417			dev_rcv_lists = &can_ml->dev_rcv_lists;
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 */
432void 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_stats = proc_create_net_single(CAN_PROC_STATS, 0644,
445			net->can.proc_dir, can_stats_proc_show, NULL);
446	net->can.pde_reset_stats = proc_create_net_single(CAN_PROC_RESET_STATS,
447			0644, net->can.proc_dir, can_reset_stats_proc_show,
448			NULL);
449	net->can.pde_rcvlist_err = proc_create_net_single(CAN_PROC_RCVLIST_ERR,
450			0644, net->can.proc_dir, can_rcvlist_proc_show,
451			(void *)RX_ERR);
452	net->can.pde_rcvlist_all = proc_create_net_single(CAN_PROC_RCVLIST_ALL,
453			0644, net->can.proc_dir, can_rcvlist_proc_show,
454			(void *)RX_ALL);
455	net->can.pde_rcvlist_fil = proc_create_net_single(CAN_PROC_RCVLIST_FIL,
456			0644, net->can.proc_dir, can_rcvlist_proc_show,
457			(void *)RX_FIL);
458	net->can.pde_rcvlist_inv = proc_create_net_single(CAN_PROC_RCVLIST_INV,
459			0644, net->can.proc_dir, can_rcvlist_proc_show,
460			(void *)RX_INV);
461	net->can.pde_rcvlist_eff = proc_create_net_single(CAN_PROC_RCVLIST_EFF,
462			0644, net->can.proc_dir, can_rcvlist_eff_proc_show, NULL);
463	net->can.pde_rcvlist_sff = proc_create_net_single(CAN_PROC_RCVLIST_SFF,
464			0644, net->can.proc_dir, can_rcvlist_sff_proc_show, NULL);
465}
466
467/*
468 * can_remove_proc - remove procfs entries and main CAN proc directory
469 */
470void can_remove_proc(struct net *net)
471{
472	if (!net->can.proc_dir)
473		return;
474
475	if (net->can.pde_stats)
476		remove_proc_entry(CAN_PROC_STATS, net->can.proc_dir);
477
478	if (net->can.pde_reset_stats)
479		remove_proc_entry(CAN_PROC_RESET_STATS, net->can.proc_dir);
480
481	if (net->can.pde_rcvlist_err)
482		remove_proc_entry(CAN_PROC_RCVLIST_ERR, net->can.proc_dir);
483
484	if (net->can.pde_rcvlist_all)
485		remove_proc_entry(CAN_PROC_RCVLIST_ALL, net->can.proc_dir);
486
487	if (net->can.pde_rcvlist_fil)
488		remove_proc_entry(CAN_PROC_RCVLIST_FIL, net->can.proc_dir);
489
490	if (net->can.pde_rcvlist_inv)
491		remove_proc_entry(CAN_PROC_RCVLIST_INV, net->can.proc_dir);
492
493	if (net->can.pde_rcvlist_eff)
494		remove_proc_entry(CAN_PROC_RCVLIST_EFF, net->can.proc_dir);
495
496	if (net->can.pde_rcvlist_sff)
497		remove_proc_entry(CAN_PROC_RCVLIST_SFF, net->can.proc_dir);
498
499	remove_proc_entry("can", net->proc_net);
500}
501