proc.c

  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	if (oldjif == newjif)
103		return 0;
104
105	/* see can_stat_update() - this should NEVER happen! */
106	if (count > (ULONG_MAX / HZ)) {
107		printk(KERN_ERR "can: calc_rate: count exceeded! %ld\n",
108		       count);
109		return 99999999;
110	}
111
112	return (count * HZ) / (newjif - oldjif);
113}
114
115void can_stat_update(struct timer_list *t)
116{
117	struct net *net = timer_container_of(net, t, can.stattimer);
118	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
119	unsigned long j = jiffies; /* snapshot */
120
121	long rx_frames = atomic_long_read(&pkg_stats->rx_frames);
122	long tx_frames = atomic_long_read(&pkg_stats->tx_frames);
123	long matches = atomic_long_read(&pkg_stats->matches);
124	long rx_frames_delta = atomic_long_read(&pkg_stats->rx_frames_delta);
125	long tx_frames_delta = atomic_long_read(&pkg_stats->tx_frames_delta);
126	long matches_delta = atomic_long_read(&pkg_stats->matches_delta);
127
128	/* restart counting in timer context on user request */
129	if (user_reset)
130		can_init_stats(net);
131
132	/* restart counting on jiffies overflow */
133	if (j < pkg_stats->jiffies_init)
134		can_init_stats(net);
135
136	/* prevent overflow in calc_rate() */
137	if (rx_frames > (LONG_MAX / HZ))
138		can_init_stats(net);
139
140	/* prevent overflow in calc_rate() */
141	if (tx_frames > (LONG_MAX / HZ))
142		can_init_stats(net);
143
144	/* matches overflow - very improbable */
145	if (matches > (LONG_MAX / 100))
146		can_init_stats(net);
147
148	/* calc total values */
149	if (rx_frames)
150		pkg_stats->total_rx_match_ratio = (matches * 100) / rx_frames;
151
152	pkg_stats->total_tx_rate = calc_rate(pkg_stats->jiffies_init, j,
153					    tx_frames);
154	pkg_stats->total_rx_rate = calc_rate(pkg_stats->jiffies_init, j,
155					    rx_frames);
156
157	/* calc current values */
158	if (rx_frames_delta)
159		pkg_stats->current_rx_match_ratio =
160			(matches_delta * 100) /	rx_frames_delta;
161
162	pkg_stats->current_tx_rate = calc_rate(0, HZ, tx_frames_delta);
163	pkg_stats->current_rx_rate = calc_rate(0, HZ, 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	atomic_long_set(&pkg_stats->tx_frames_delta, 0);
177	atomic_long_set(&pkg_stats->rx_frames_delta, 0);
178	atomic_long_set(&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
188static 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, atomic_long_read(&r->matches),
200			   r->ident);
201	}
202}
203
204static void can_print_recv_banner(struct seq_file *m)
205{
206	/*
207	 *                  can1.  00000000  00000000  00000000
208	 *                 .......          0  tp20
209	 */
210	if (IS_ENABLED(CONFIG_64BIT))
211		seq_puts(m, "  device   can_id   can_mask      function          userdata       matches  ident\n");
212	else
213		seq_puts(m, "  device   can_id   can_mask  function  userdata   matches  ident\n");
214}
215
216static int can_stats_proc_show(struct seq_file *m, void *v)
217{
218	struct net *net = m->private;
219	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
220	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
221
222	seq_putc(m, '\n');
223	seq_printf(m, " %8ld transmitted frames (TXF)\n",
224		   atomic_long_read(&pkg_stats->tx_frames));
225	seq_printf(m, " %8ld received frames (RXF)\n",
226		   atomic_long_read(&pkg_stats->rx_frames));
227	seq_printf(m, " %8ld matched frames (RXMF)\n",
228		   atomic_long_read(&pkg_stats->matches));
229
230	seq_putc(m, '\n');
231
232	if (net->can.stattimer.function == can_stat_update) {
233		seq_printf(m, " %8ld %% total match ratio (RXMR)\n",
234				pkg_stats->total_rx_match_ratio);
235
236		seq_printf(m, " %8ld frames/s total tx rate (TXR)\n",
237				pkg_stats->total_tx_rate);
238		seq_printf(m, " %8ld frames/s total rx rate (RXR)\n",
239				pkg_stats->total_rx_rate);
240
241		seq_putc(m, '\n');
242
243		seq_printf(m, " %8ld %% current match ratio (CRXMR)\n",
244				pkg_stats->current_rx_match_ratio);
245
246		seq_printf(m, " %8ld frames/s current tx rate (CTXR)\n",
247				pkg_stats->current_tx_rate);
248		seq_printf(m, " %8ld frames/s current rx rate (CRXR)\n",
249				pkg_stats->current_rx_rate);
250
251		seq_putc(m, '\n');
252
253		seq_printf(m, " %8ld %% max match ratio (MRXMR)\n",
254				pkg_stats->max_rx_match_ratio);
255
256		seq_printf(m, " %8ld frames/s max tx rate (MTXR)\n",
257				pkg_stats->max_tx_rate);
258		seq_printf(m, " %8ld frames/s max rx rate (MRXR)\n",
259				pkg_stats->max_rx_rate);
260
261		seq_putc(m, '\n');
262	}
263
264	seq_printf(m, " %8ld current receive list entries (CRCV)\n",
265			rcv_lists_stats->rcv_entries);
266	seq_printf(m, " %8ld maximum receive list entries (MRCV)\n",
267			rcv_lists_stats->rcv_entries_max);
268
269	if (rcv_lists_stats->stats_reset)
270		seq_printf(m, "\n %8ld statistic resets (STR)\n",
271				rcv_lists_stats->stats_reset);
272
273	if (rcv_lists_stats->user_reset)
274		seq_printf(m, " %8ld user statistic resets (USTR)\n",
275				rcv_lists_stats->user_reset);
276
277	seq_putc(m, '\n');
278	return 0;
279}
280
281static int can_reset_stats_proc_show(struct seq_file *m, void *v)
282{
283	struct net *net = m->private;
284	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
285	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
286
287	user_reset = 1;
288
289	if (net->can.stattimer.function == can_stat_update) {
290		seq_printf(m, "Scheduled statistic reset #%ld.\n",
291				rcv_lists_stats->stats_reset + 1);
292	} else {
293		if (pkg_stats->jiffies_init != jiffies)
294			can_init_stats(net);
295
296		seq_printf(m, "Performed statistic reset #%ld.\n",
297				rcv_lists_stats->stats_reset);
298	}
299	return 0;
300}
301
302static 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
314static 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		struct can_ml_priv *can_ml = can_get_ml_priv(dev);
333
334		if (can_ml)
335			can_rcvlist_proc_show_one(m, idx, dev,
336						  &can_ml->dev_rcv_lists);
337	}
338
339	rcu_read_unlock();
340
341	seq_putc(m, '\n');
342	return 0;
343}
344
345static inline void can_rcvlist_proc_show_array(struct seq_file *m,
346					       struct net_device *dev,
347					       struct hlist_head *rcv_array,
348					       unsigned int rcv_array_sz)
349{
350	unsigned int i;
351	int all_empty = 1;
352
353	/* check whether at least one list is non-empty */
354	for (i = 0; i < rcv_array_sz; i++)
355		if (!hlist_empty(&rcv_array[i])) {
356			all_empty = 0;
357			break;
358		}
359
360	if (!all_empty) {
361		can_print_recv_banner(m);
362		for (i = 0; i < rcv_array_sz; i++) {
363			if (!hlist_empty(&rcv_array[i]))
364				can_print_rcvlist(m, &rcv_array[i], dev);
365		}
366	} else
367		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
368}
369
370static int can_rcvlist_sff_proc_show(struct seq_file *m, void *v)
371{
372	struct net_device *dev;
373	struct can_dev_rcv_lists *dev_rcv_lists;
374	struct net *net = m->private;
375
376	/* RX_SFF */
377	seq_puts(m, "\nreceive list 'rx_sff':\n");
378
379	rcu_read_lock();
380
381	/* sff receive list for 'all' CAN devices (dev == NULL) */
382	dev_rcv_lists = net->can.rx_alldev_list;
383	can_rcvlist_proc_show_array(m, NULL, dev_rcv_lists->rx_sff,
384				    ARRAY_SIZE(dev_rcv_lists->rx_sff));
385
386	/* sff receive list for registered CAN devices */
387	for_each_netdev_rcu(net, dev) {
388		struct can_ml_priv *can_ml = can_get_ml_priv(dev);
389
390		if (can_ml) {
391			dev_rcv_lists = &can_ml->dev_rcv_lists;
392			can_rcvlist_proc_show_array(m, dev, dev_rcv_lists->rx_sff,
393						    ARRAY_SIZE(dev_rcv_lists->rx_sff));
394		}
395	}
396
397	rcu_read_unlock();
398
399	seq_putc(m, '\n');
400	return 0;
401}
402
403static int can_rcvlist_eff_proc_show(struct seq_file *m, void *v)
404{
405	struct net_device *dev;
406	struct can_dev_rcv_lists *dev_rcv_lists;
407	struct net *net = m->private;
408
409	/* RX_EFF */
410	seq_puts(m, "\nreceive list 'rx_eff':\n");
411
412	rcu_read_lock();
413
414	/* eff receive list for 'all' CAN devices (dev == NULL) */
415	dev_rcv_lists = net->can.rx_alldev_list;
416	can_rcvlist_proc_show_array(m, NULL, dev_rcv_lists->rx_eff,
417				    ARRAY_SIZE(dev_rcv_lists->rx_eff));
418
419	/* eff receive list for registered CAN devices */
420	for_each_netdev_rcu(net, dev) {
421		struct can_ml_priv *can_ml = can_get_ml_priv(dev);
422
423		if (can_ml) {
424			dev_rcv_lists = &can_ml->dev_rcv_lists;
425			can_rcvlist_proc_show_array(m, dev, dev_rcv_lists->rx_eff,
426						    ARRAY_SIZE(dev_rcv_lists->rx_eff));
427		}
428	}
429
430	rcu_read_unlock();
431
432	seq_putc(m, '\n');
433	return 0;
434}
435
436/*
437 * can_init_proc - create main CAN proc directory and procfs entries
438 */
439void can_init_proc(struct net *net)
440{
441	/* create /proc/net/can directory */
442	net->can.proc_dir = proc_net_mkdir(net, "can", net->proc_net);
443
444	if (!net->can.proc_dir) {
445		printk(KERN_INFO "can: failed to create /proc/net/can . "
446			   "CONFIG_PROC_FS missing?\n");
447		return;
448	}
449
450	/* own procfs entries from the AF_CAN core */
451	net->can.pde_stats = proc_create_net_single(CAN_PROC_STATS, 0644,
452			net->can.proc_dir, can_stats_proc_show, NULL);
453	net->can.pde_reset_stats = proc_create_net_single(CAN_PROC_RESET_STATS,
454			0644, net->can.proc_dir, can_reset_stats_proc_show,
455			NULL);
456	net->can.pde_rcvlist_err = proc_create_net_single(CAN_PROC_RCVLIST_ERR,
457			0644, net->can.proc_dir, can_rcvlist_proc_show,
458			(void *)RX_ERR);
459	net->can.pde_rcvlist_all = proc_create_net_single(CAN_PROC_RCVLIST_ALL,
460			0644, net->can.proc_dir, can_rcvlist_proc_show,
461			(void *)RX_ALL);
462	net->can.pde_rcvlist_fil = proc_create_net_single(CAN_PROC_RCVLIST_FIL,
463			0644, net->can.proc_dir, can_rcvlist_proc_show,
464			(void *)RX_FIL);
465	net->can.pde_rcvlist_inv = proc_create_net_single(CAN_PROC_RCVLIST_INV,
466			0644, net->can.proc_dir, can_rcvlist_proc_show,
467			(void *)RX_INV);
468	net->can.pde_rcvlist_eff = proc_create_net_single(CAN_PROC_RCVLIST_EFF,
469			0644, net->can.proc_dir, can_rcvlist_eff_proc_show, NULL);
470	net->can.pde_rcvlist_sff = proc_create_net_single(CAN_PROC_RCVLIST_SFF,
471			0644, net->can.proc_dir, can_rcvlist_sff_proc_show, NULL);
472}
473
474/*
475 * can_remove_proc - remove procfs entries and main CAN proc directory
476 */
477void can_remove_proc(struct net *net)
478{
479	if (!net->can.proc_dir)
480		return;
481
482	if (net->can.pde_stats)
483		remove_proc_entry(CAN_PROC_STATS, net->can.proc_dir);
484
485	if (net->can.pde_reset_stats)
486		remove_proc_entry(CAN_PROC_RESET_STATS, net->can.proc_dir);
487
488	if (net->can.pde_rcvlist_err)
489		remove_proc_entry(CAN_PROC_RCVLIST_ERR, net->can.proc_dir);
490
491	if (net->can.pde_rcvlist_all)
492		remove_proc_entry(CAN_PROC_RCVLIST_ALL, net->can.proc_dir);
493
494	if (net->can.pde_rcvlist_fil)
495		remove_proc_entry(CAN_PROC_RCVLIST_FIL, net->can.proc_dir);
496
497	if (net->can.pde_rcvlist_inv)
498		remove_proc_entry(CAN_PROC_RCVLIST_INV, net->can.proc_dir);
499
500	if (net->can.pde_rcvlist_eff)
501		remove_proc_entry(CAN_PROC_RCVLIST_EFF, net->can.proc_dir);
502
503	if (net->can.pde_rcvlist_sff)
504		remove_proc_entry(CAN_PROC_RCVLIST_SFF, net->can.proc_dir);
505
506	remove_proc_entry("can", net->proc_net);
507}