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 
can_init_stats(struct net * net)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 
calc_rate(unsigned long oldjif,unsigned long newjif,unsigned long count)99 static 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 
can_stat_update(struct timer_list * t)115 void can_stat_update(struct timer_list *t)
116 {
117 	struct net *net = from_timer(net, t, can.stattimer);
118 	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
119 	unsigned long j = jiffies; /* snapshot */
120 
121 	/* restart counting in timer context on user request */
122 	if (user_reset)
123 		can_init_stats(net);
124 
125 	/* restart counting on jiffies overflow */
126 	if (j < pkg_stats->jiffies_init)
127 		can_init_stats(net);
128 
129 	/* prevent overflow in calc_rate() */
130 	if (pkg_stats->rx_frames > (ULONG_MAX / HZ))
131 		can_init_stats(net);
132 
133 	/* prevent overflow in calc_rate() */
134 	if (pkg_stats->tx_frames > (ULONG_MAX / HZ))
135 		can_init_stats(net);
136 
137 	/* matches overflow - very improbable */
138 	if (pkg_stats->matches > (ULONG_MAX / 100))
139 		can_init_stats(net);
140 
141 	/* calc total values */
142 	if (pkg_stats->rx_frames)
143 		pkg_stats->total_rx_match_ratio = (pkg_stats->matches * 100) /
144 			pkg_stats->rx_frames;
145 
146 	pkg_stats->total_tx_rate = calc_rate(pkg_stats->jiffies_init, j,
147 					    pkg_stats->tx_frames);
148 	pkg_stats->total_rx_rate = calc_rate(pkg_stats->jiffies_init, j,
149 					    pkg_stats->rx_frames);
150 
151 	/* calc current values */
152 	if (pkg_stats->rx_frames_delta)
153 		pkg_stats->current_rx_match_ratio =
154 			(pkg_stats->matches_delta * 100) /
155 			pkg_stats->rx_frames_delta;
156 
157 	pkg_stats->current_tx_rate = calc_rate(0, HZ, pkg_stats->tx_frames_delta);
158 	pkg_stats->current_rx_rate = calc_rate(0, HZ, pkg_stats->rx_frames_delta);
159 
160 	/* check / update maximum values */
161 	if (pkg_stats->max_tx_rate < pkg_stats->current_tx_rate)
162 		pkg_stats->max_tx_rate = pkg_stats->current_tx_rate;
163 
164 	if (pkg_stats->max_rx_rate < pkg_stats->current_rx_rate)
165 		pkg_stats->max_rx_rate = pkg_stats->current_rx_rate;
166 
167 	if (pkg_stats->max_rx_match_ratio < pkg_stats->current_rx_match_ratio)
168 		pkg_stats->max_rx_match_ratio = pkg_stats->current_rx_match_ratio;
169 
170 	/* clear values for 'current rate' calculation */
171 	pkg_stats->tx_frames_delta = 0;
172 	pkg_stats->rx_frames_delta = 0;
173 	pkg_stats->matches_delta   = 0;
174 
175 	/* restart timer (one second) */
176 	mod_timer(&net->can.stattimer, round_jiffies(jiffies + HZ));
177 }
178 
179 /*
180  * proc read functions
181  */
182 
can_print_rcvlist(struct seq_file * m,struct hlist_head * rx_list,struct net_device * dev)183 static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list,
184 			      struct net_device *dev)
185 {
186 	struct receiver *r;
187 
188 	hlist_for_each_entry_rcu(r, rx_list, list) {
189 		char *fmt = (r->can_id & CAN_EFF_FLAG)?
190 			"   %-5s  %08x  %08x  %pK  %pK  %8ld  %s\n" :
191 			"   %-5s     %03x    %08x  %pK  %pK  %8ld  %s\n";
192 
193 		seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
194 				r->func, r->data, r->matches, r->ident);
195 	}
196 }
197 
can_print_recv_banner(struct seq_file * m)198 static void can_print_recv_banner(struct seq_file *m)
199 {
200 	/*
201 	 *                  can1.  00000000  00000000  00000000
202 	 *                 .......          0  tp20
203 	 */
204 	if (IS_ENABLED(CONFIG_64BIT))
205 		seq_puts(m, "  device   can_id   can_mask      function          userdata       matches  ident\n");
206 	else
207 		seq_puts(m, "  device   can_id   can_mask  function  userdata   matches  ident\n");
208 }
209 
can_stats_proc_show(struct seq_file * m,void * v)210 static int can_stats_proc_show(struct seq_file *m, void *v)
211 {
212 	struct net *net = m->private;
213 	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
214 	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
215 
216 	seq_putc(m, '\n');
217 	seq_printf(m, " %8ld transmitted frames (TXF)\n", pkg_stats->tx_frames);
218 	seq_printf(m, " %8ld received frames (RXF)\n", pkg_stats->rx_frames);
219 	seq_printf(m, " %8ld matched frames (RXMF)\n", pkg_stats->matches);
220 
221 	seq_putc(m, '\n');
222 
223 	if (net->can.stattimer.function == can_stat_update) {
224 		seq_printf(m, " %8ld %% total match ratio (RXMR)\n",
225 				pkg_stats->total_rx_match_ratio);
226 
227 		seq_printf(m, " %8ld frames/s total tx rate (TXR)\n",
228 				pkg_stats->total_tx_rate);
229 		seq_printf(m, " %8ld frames/s total rx rate (RXR)\n",
230 				pkg_stats->total_rx_rate);
231 
232 		seq_putc(m, '\n');
233 
234 		seq_printf(m, " %8ld %% current match ratio (CRXMR)\n",
235 				pkg_stats->current_rx_match_ratio);
236 
237 		seq_printf(m, " %8ld frames/s current tx rate (CTXR)\n",
238 				pkg_stats->current_tx_rate);
239 		seq_printf(m, " %8ld frames/s current rx rate (CRXR)\n",
240 				pkg_stats->current_rx_rate);
241 
242 		seq_putc(m, '\n');
243 
244 		seq_printf(m, " %8ld %% max match ratio (MRXMR)\n",
245 				pkg_stats->max_rx_match_ratio);
246 
247 		seq_printf(m, " %8ld frames/s max tx rate (MTXR)\n",
248 				pkg_stats->max_tx_rate);
249 		seq_printf(m, " %8ld frames/s max rx rate (MRXR)\n",
250 				pkg_stats->max_rx_rate);
251 
252 		seq_putc(m, '\n');
253 	}
254 
255 	seq_printf(m, " %8ld current receive list entries (CRCV)\n",
256 			rcv_lists_stats->rcv_entries);
257 	seq_printf(m, " %8ld maximum receive list entries (MRCV)\n",
258 			rcv_lists_stats->rcv_entries_max);
259 
260 	if (rcv_lists_stats->stats_reset)
261 		seq_printf(m, "\n %8ld statistic resets (STR)\n",
262 				rcv_lists_stats->stats_reset);
263 
264 	if (rcv_lists_stats->user_reset)
265 		seq_printf(m, " %8ld user statistic resets (USTR)\n",
266 				rcv_lists_stats->user_reset);
267 
268 	seq_putc(m, '\n');
269 	return 0;
270 }
271 
can_reset_stats_proc_show(struct seq_file * m,void * v)272 static int can_reset_stats_proc_show(struct seq_file *m, void *v)
273 {
274 	struct net *net = m->private;
275 	struct can_rcv_lists_stats *rcv_lists_stats = net->can.rcv_lists_stats;
276 	struct can_pkg_stats *pkg_stats = net->can.pkg_stats;
277 
278 	user_reset = 1;
279 
280 	if (net->can.stattimer.function == can_stat_update) {
281 		seq_printf(m, "Scheduled statistic reset #%ld.\n",
282 				rcv_lists_stats->stats_reset + 1);
283 	} else {
284 		if (pkg_stats->jiffies_init != jiffies)
285 			can_init_stats(net);
286 
287 		seq_printf(m, "Performed statistic reset #%ld.\n",
288 				rcv_lists_stats->stats_reset);
289 	}
290 	return 0;
291 }
292 
can_rcvlist_proc_show_one(struct seq_file * m,int idx,struct net_device * dev,struct can_dev_rcv_lists * dev_rcv_lists)293 static inline void can_rcvlist_proc_show_one(struct seq_file *m, int idx,
294 					     struct net_device *dev,
295 					     struct can_dev_rcv_lists *dev_rcv_lists)
296 {
297 	if (!hlist_empty(&dev_rcv_lists->rx[idx])) {
298 		can_print_recv_banner(m);
299 		can_print_rcvlist(m, &dev_rcv_lists->rx[idx], dev);
300 	} else
301 		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
302 
303 }
304 
can_rcvlist_proc_show(struct seq_file * m,void * v)305 static int can_rcvlist_proc_show(struct seq_file *m, void *v)
306 {
307 	/* double cast to prevent GCC warning */
308 	int idx = (int)(long)PDE_DATA(m->file->f_inode);
309 	struct net_device *dev;
310 	struct can_dev_rcv_lists *dev_rcv_lists;
311 	struct net *net = m->private;
312 
313 	seq_printf(m, "\nreceive list '%s':\n", rx_list_name[idx]);
314 
315 	rcu_read_lock();
316 
317 	/* receive list for 'all' CAN devices (dev == NULL) */
318 	dev_rcv_lists = net->can.rx_alldev_list;
319 	can_rcvlist_proc_show_one(m, idx, NULL, dev_rcv_lists);
320 
321 	/* receive list for registered CAN devices */
322 	for_each_netdev_rcu(net, dev) {
323 		struct can_ml_priv *can_ml = can_get_ml_priv(dev);
324 
325 		if (can_ml)
326 			can_rcvlist_proc_show_one(m, idx, dev,
327 						  &can_ml->dev_rcv_lists);
328 	}
329 
330 	rcu_read_unlock();
331 
332 	seq_putc(m, '\n');
333 	return 0;
334 }
335 
can_rcvlist_proc_show_array(struct seq_file * m,struct net_device * dev,struct hlist_head * rcv_array,unsigned int rcv_array_sz)336 static inline void can_rcvlist_proc_show_array(struct seq_file *m,
337 					       struct net_device *dev,
338 					       struct hlist_head *rcv_array,
339 					       unsigned int rcv_array_sz)
340 {
341 	unsigned int i;
342 	int all_empty = 1;
343 
344 	/* check whether at least one list is non-empty */
345 	for (i = 0; i < rcv_array_sz; i++)
346 		if (!hlist_empty(&rcv_array[i])) {
347 			all_empty = 0;
348 			break;
349 		}
350 
351 	if (!all_empty) {
352 		can_print_recv_banner(m);
353 		for (i = 0; i < rcv_array_sz; i++) {
354 			if (!hlist_empty(&rcv_array[i]))
355 				can_print_rcvlist(m, &rcv_array[i], dev);
356 		}
357 	} else
358 		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
359 }
360 
can_rcvlist_sff_proc_show(struct seq_file * m,void * v)361 static int can_rcvlist_sff_proc_show(struct seq_file *m, void *v)
362 {
363 	struct net_device *dev;
364 	struct can_dev_rcv_lists *dev_rcv_lists;
365 	struct net *net = m->private;
366 
367 	/* RX_SFF */
368 	seq_puts(m, "\nreceive list 'rx_sff':\n");
369 
370 	rcu_read_lock();
371 
372 	/* sff receive list for 'all' CAN devices (dev == NULL) */
373 	dev_rcv_lists = net->can.rx_alldev_list;
374 	can_rcvlist_proc_show_array(m, NULL, dev_rcv_lists->rx_sff,
375 				    ARRAY_SIZE(dev_rcv_lists->rx_sff));
376 
377 	/* sff receive list for registered CAN devices */
378 	for_each_netdev_rcu(net, dev) {
379 		struct can_ml_priv *can_ml = can_get_ml_priv(dev);
380 
381 		if (can_ml) {
382 			dev_rcv_lists = &can_ml->dev_rcv_lists;
383 			can_rcvlist_proc_show_array(m, dev, dev_rcv_lists->rx_sff,
384 						    ARRAY_SIZE(dev_rcv_lists->rx_sff));
385 		}
386 	}
387 
388 	rcu_read_unlock();
389 
390 	seq_putc(m, '\n');
391 	return 0;
392 }
393 
can_rcvlist_eff_proc_show(struct seq_file * m,void * v)394 static int can_rcvlist_eff_proc_show(struct seq_file *m, void *v)
395 {
396 	struct net_device *dev;
397 	struct can_dev_rcv_lists *dev_rcv_lists;
398 	struct net *net = m->private;
399 
400 	/* RX_EFF */
401 	seq_puts(m, "\nreceive list 'rx_eff':\n");
402 
403 	rcu_read_lock();
404 
405 	/* eff receive list for 'all' CAN devices (dev == NULL) */
406 	dev_rcv_lists = net->can.rx_alldev_list;
407 	can_rcvlist_proc_show_array(m, NULL, dev_rcv_lists->rx_eff,
408 				    ARRAY_SIZE(dev_rcv_lists->rx_eff));
409 
410 	/* eff receive list for registered CAN devices */
411 	for_each_netdev_rcu(net, dev) {
412 		struct can_ml_priv *can_ml = can_get_ml_priv(dev);
413 
414 		if (can_ml) {
415 			dev_rcv_lists = &can_ml->dev_rcv_lists;
416 			can_rcvlist_proc_show_array(m, dev, dev_rcv_lists->rx_eff,
417 						    ARRAY_SIZE(dev_rcv_lists->rx_eff));
418 		}
419 	}
420 
421 	rcu_read_unlock();
422 
423 	seq_putc(m, '\n');
424 	return 0;
425 }
426 
427 /*
428  * can_init_proc - create main CAN proc directory and procfs entries
429  */
can_init_proc(struct net * net)430 void can_init_proc(struct net *net)
431 {
432 	/* create /proc/net/can directory */
433 	net->can.proc_dir = proc_net_mkdir(net, "can", net->proc_net);
434 
435 	if (!net->can.proc_dir) {
436 		printk(KERN_INFO "can: failed to create /proc/net/can . "
437 			   "CONFIG_PROC_FS missing?\n");
438 		return;
439 	}
440 
441 	/* own procfs entries from the AF_CAN core */
442 	net->can.pde_stats = proc_create_net_single(CAN_PROC_STATS, 0644,
443 			net->can.proc_dir, can_stats_proc_show, NULL);
444 	net->can.pde_reset_stats = proc_create_net_single(CAN_PROC_RESET_STATS,
445 			0644, net->can.proc_dir, can_reset_stats_proc_show,
446 			NULL);
447 	net->can.pde_rcvlist_err = proc_create_net_single(CAN_PROC_RCVLIST_ERR,
448 			0644, net->can.proc_dir, can_rcvlist_proc_show,
449 			(void *)RX_ERR);
450 	net->can.pde_rcvlist_all = proc_create_net_single(CAN_PROC_RCVLIST_ALL,
451 			0644, net->can.proc_dir, can_rcvlist_proc_show,
452 			(void *)RX_ALL);
453 	net->can.pde_rcvlist_fil = proc_create_net_single(CAN_PROC_RCVLIST_FIL,
454 			0644, net->can.proc_dir, can_rcvlist_proc_show,
455 			(void *)RX_FIL);
456 	net->can.pde_rcvlist_inv = proc_create_net_single(CAN_PROC_RCVLIST_INV,
457 			0644, net->can.proc_dir, can_rcvlist_proc_show,
458 			(void *)RX_INV);
459 	net->can.pde_rcvlist_eff = proc_create_net_single(CAN_PROC_RCVLIST_EFF,
460 			0644, net->can.proc_dir, can_rcvlist_eff_proc_show, NULL);
461 	net->can.pde_rcvlist_sff = proc_create_net_single(CAN_PROC_RCVLIST_SFF,
462 			0644, net->can.proc_dir, can_rcvlist_sff_proc_show, NULL);
463 }
464 
465 /*
466  * can_remove_proc - remove procfs entries and main CAN proc directory
467  */
can_remove_proc(struct net * net)468 void can_remove_proc(struct net *net)
469 {
470 	if (!net->can.proc_dir)
471 		return;
472 
473 	if (net->can.pde_stats)
474 		remove_proc_entry(CAN_PROC_STATS, net->can.proc_dir);
475 
476 	if (net->can.pde_reset_stats)
477 		remove_proc_entry(CAN_PROC_RESET_STATS, net->can.proc_dir);
478 
479 	if (net->can.pde_rcvlist_err)
480 		remove_proc_entry(CAN_PROC_RCVLIST_ERR, net->can.proc_dir);
481 
482 	if (net->can.pde_rcvlist_all)
483 		remove_proc_entry(CAN_PROC_RCVLIST_ALL, net->can.proc_dir);
484 
485 	if (net->can.pde_rcvlist_fil)
486 		remove_proc_entry(CAN_PROC_RCVLIST_FIL, net->can.proc_dir);
487 
488 	if (net->can.pde_rcvlist_inv)
489 		remove_proc_entry(CAN_PROC_RCVLIST_INV, net->can.proc_dir);
490 
491 	if (net->can.pde_rcvlist_eff)
492 		remove_proc_entry(CAN_PROC_RCVLIST_EFF, net->can.proc_dir);
493 
494 	if (net->can.pde_rcvlist_sff)
495 		remove_proc_entry(CAN_PROC_RCVLIST_SFF, net->can.proc_dir);
496 
497 	remove_proc_entry("can", net->proc_net);
498 }
499