net/can/proc.c

   1 /*
   2  * proc.c - procfs support for Protocol family CAN core module
   3  *
   4  * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of Volkswagen nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * Alternatively, provided that this notice is retained in full, this
  20  * software may be distributed under the terms of the GNU General
  21  * Public License ("GPL") version 2, in which case the provisions of the
  22  * GPL apply INSTEAD OF those given above.
  23  *
  24  * The provided data structures and external interfaces from this code
  25  * are not restricted to be used by modules with a GPL compatible license.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  28  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  29  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  30  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  31  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  32  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  33  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  34  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  35  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  36  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  37  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
  38  * DAMAGE.
  39  *
  40  * Send feedback to <socketcan-users@lists.berlios.de>
  41  *
  42  */
  43
  44 #include <linux/module.h>
  45 #include <linux/proc_fs.h>
  46 #include <linux/list.h>
  47 #include <linux/rcupdate.h>
  48 #include <linux/can/core.h>
  49
  50 #include "af_can.h"
  51
  52 /*
  53  * proc filenames for the PF_CAN core
  54  */
  55
  56 #define CAN_PROC_VERSION     "version"
  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 struct proc_dir_entry *can_dir;
  67 static struct proc_dir_entry *pde_version;
  68 static struct proc_dir_entry *pde_stats;
  69 static struct proc_dir_entry *pde_reset_stats;
  70 static struct proc_dir_entry *pde_rcvlist_all;
  71 static struct proc_dir_entry *pde_rcvlist_fil;
  72 static struct proc_dir_entry *pde_rcvlist_inv;
  73 static struct proc_dir_entry *pde_rcvlist_sff;
  74 static struct proc_dir_entry *pde_rcvlist_eff;
  75 static struct proc_dir_entry *pde_rcvlist_err;
  76
  77 static int user_reset;
  78
  79 static const char rx_list_name[][8] = {
  80         [RX_ERR] = "rx_err",
  81         [RX_ALL] = "rx_all",
  82         [RX_FIL] = "rx_fil",
  83         [RX_INV] = "rx_inv",
  84         [RX_EFF] = "rx_eff",
  85 };
  86
  87 /*
  88  * af_can statistics stuff
  89  */
  90
  91 static void can_init_stats(void)
  92 {
  93         /*
  94          * This memset function is called from a timer context (when
  95          * can_stattimer is active which is the default) OR in a process
  96          * context (reading the proc_fs when can_stattimer is disabled).
  97          */
  98         memset(&can_stats, 0, sizeof(can_stats));
  99         can_stats.jiffies_init = jiffies;
 100
 101         can_pstats.stats_reset++;
 102
 103         if (user_reset) {
 104                 user_reset = 0;
 105                 can_pstats.user_reset++;
 106         }
 107 }
 108
 109 static unsigned long calc_rate(unsigned long oldjif, unsigned long newjif,
 110                                unsigned long count)
 111 {
 112         unsigned long rate;
 113
 114         if (oldjif == newjif)
 115                 return 0;
 116
 117         /* see can_stat_update() - this should NEVER happen! */
 118         if (count > (ULONG_MAX / HZ)) {
 119                 printk(KERN_ERR "can: calc_rate: count exceeded! %ld\n",
 120                        count);
 121                 return 99999999;
 122         }
 123
 124         rate = (count * HZ) / (newjif - oldjif);
 125
 126         return rate;
 127 }
 128
 129 void can_stat_update(unsigned long data)
 130 {
 131         unsigned long j = jiffies; /* snapshot */
 132
 133         /* restart counting in timer context on user request */
 134         if (user_reset)
 135                 can_init_stats();
 136
 137         /* restart counting on jiffies overflow */
 138         if (j < can_stats.jiffies_init)
 139                 can_init_stats();
 140
 141         /* prevent overflow in calc_rate() */
 142         if (can_stats.rx_frames > (ULONG_MAX / HZ))
 143                 can_init_stats();
 144
 145         /* prevent overflow in calc_rate() */
 146         if (can_stats.tx_frames > (ULONG_MAX / HZ))
 147                 can_init_stats();
 148
 149         /* matches overflow - very improbable */
 150         if (can_stats.matches > (ULONG_MAX / 100))
 151                 can_init_stats();
 152
 153         /* calc total values */
 154         if (can_stats.rx_frames)
 155                 can_stats.total_rx_match_ratio = (can_stats.matches * 100) /
 156                         can_stats.rx_frames;
 157
 158         can_stats.total_tx_rate = calc_rate(can_stats.jiffies_init, j,
 159                                             can_stats.tx_frames);
 160         can_stats.total_rx_rate = calc_rate(can_stats.jiffies_init, j,
 161                                             can_stats.rx_frames);
 162
 163         /* calc current values */
 164         if (can_stats.rx_frames_delta)
 165                 can_stats.current_rx_match_ratio =
 166                         (can_stats.matches_delta * 100) /
 167                         can_stats.rx_frames_delta;
 168
 169         can_stats.current_tx_rate = calc_rate(0, HZ, can_stats.tx_frames_delta);
 170         can_stats.current_rx_rate = calc_rate(0, HZ, can_stats.rx_frames_delta);
 171
 172         /* check / update maximum values */
 173         if (can_stats.max_tx_rate < can_stats.current_tx_rate)
 174                 can_stats.max_tx_rate = can_stats.current_tx_rate;
 175
 176         if (can_stats.max_rx_rate < can_stats.current_rx_rate)
 177                 can_stats.max_rx_rate = can_stats.current_rx_rate;
 178
 179         if (can_stats.max_rx_match_ratio < can_stats.current_rx_match_ratio)
 180                 can_stats.max_rx_match_ratio = can_stats.current_rx_match_ratio;
 181
 182         /* clear values for 'current rate' calculation */
 183         can_stats.tx_frames_delta = 0;
 184         can_stats.rx_frames_delta = 0;
 185         can_stats.matches_delta   = 0;
 186
 187         /* restart timer (one second) */
 188         mod_timer(&can_stattimer, round_jiffies(jiffies + HZ));
 189 }
 190
 191 /*
 192  * proc read functions
 193  *
 194  * From known use-cases we expect about 10 entries in a receive list to be
 195  * printed in the proc_fs. So PAGE_SIZE is definitely enough space here.
 196  *
 197  */
 198
 199 static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list,
 200                               struct net_device *dev)
 201 {
 202         struct receiver *r;
 203         struct hlist_node *n;
 204
 205         rcu_read_lock();
 206         hlist_for_each_entry_rcu(r, n, rx_list, list) {
 207                 char *fmt = (r->can_id & CAN_EFF_FLAG)?
 208                         "   %-5s  %08X  %08x  %08x  %08x  %8ld  %s\n" :
 209                         "   %-5s     %03X    %08x  %08lx  %08lx  %8ld  %s\n";
 210
 211                 seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
 212                                 (unsigned long)r->func, (unsigned long)r->data,
 213                                 r->matches, r->ident);
 214         }
 215         rcu_read_unlock();
 216 }
 217
 218 static void can_print_recv_banner(struct seq_file *m)
 219 {
 220         /*
 221          *                  can1.  00000000  00000000  00000000
 222          *                 .......          0  tp20
 223          */
 224         seq_puts(m, "  device   can_id   can_mask  function"
 225                         "  userdata   matches  ident\n");
 226 }
 227
 228 static int can_stats_proc_show(struct seq_file *m, void *v)
 229 {
 230         seq_putc(m, '\n');
 231         seq_printf(m, " %8ld transmitted frames (TXF)\n", can_stats.tx_frames);
 232         seq_printf(m, " %8ld received frames (RXF)\n", can_stats.rx_frames);
 233         seq_printf(m, " %8ld matched frames (RXMF)\n", can_stats.matches);
 234
 235         seq_putc(m, '\n');
 236
 237         if (can_stattimer.function == can_stat_update) {
 238                 seq_printf(m, " %8ld %% total match ratio (RXMR)\n",
 239                                 can_stats.total_rx_match_ratio);
 240
 241                 seq_printf(m, " %8ld frames/s total tx rate (TXR)\n",
 242                                 can_stats.total_tx_rate);
 243                 seq_printf(m, " %8ld frames/s total rx rate (RXR)\n",
 244                                 can_stats.total_rx_rate);
 245
 246                 seq_putc(m, '\n');
 247
 248                 seq_printf(m, " %8ld %% current match ratio (CRXMR)\n",
 249                                 can_stats.current_rx_match_ratio);
 250
 251                 seq_printf(m, " %8ld frames/s current tx rate (CTXR)\n",
 252                                 can_stats.current_tx_rate);
 253                 seq_printf(m, " %8ld frames/s current rx rate (CRXR)\n",
 254                                 can_stats.current_rx_rate);
 255
 256                 seq_putc(m, '\n');
 257
 258                 seq_printf(m, " %8ld %% max match ratio (MRXMR)\n",
 259                                 can_stats.max_rx_match_ratio);
 260
 261                 seq_printf(m, " %8ld frames/s max tx rate (MTXR)\n",
 262                                 can_stats.max_tx_rate);
 263                 seq_printf(m, " %8ld frames/s max rx rate (MRXR)\n",
 264                                 can_stats.max_rx_rate);
 265
 266                 seq_putc(m, '\n');
 267         }
 268
 269         seq_printf(m, " %8ld current receive list entries (CRCV)\n",
 270                         can_pstats.rcv_entries);
 271         seq_printf(m, " %8ld maximum receive list entries (MRCV)\n",
 272                         can_pstats.rcv_entries_max);
 273
 274         if (can_pstats.stats_reset)
 275                 seq_printf(m, "\n %8ld statistic resets (STR)\n",
 276                                 can_pstats.stats_reset);
 277
 278         if (can_pstats.user_reset)
 279                 seq_printf(m, " %8ld user statistic resets (USTR)\n",
 280                                 can_pstats.user_reset);
 281
 282         seq_putc(m, '\n');
 283         return 0;
 284 }
 285
 286 static int can_stats_proc_open(struct inode *inode, struct file *file)
 287 {
 288         return single_open(file, can_stats_proc_show, NULL);
 289 }
 290
 291 static const struct file_operations can_stats_proc_fops = {
 292         .owner          = THIS_MODULE,
 293         .open           = can_stats_proc_open,
 294         .read           = seq_read,
 295         .llseek         = seq_lseek,
 296         .release        = single_release,
 297 };
 298
 299 static int can_reset_stats_proc_show(struct seq_file *m, void *v)
 300 {
 301         user_reset = 1;
 302
 303         if (can_stattimer.function == can_stat_update) {
 304                 seq_printf(m, "Scheduled statistic reset #%ld.\n",
 305                                 can_pstats.stats_reset + 1);
 306
 307         } else {
 308                 if (can_stats.jiffies_init != jiffies)
 309                         can_init_stats();
 310
 311                 seq_printf(m, "Performed statistic reset #%ld.\n",
 312                                 can_pstats.stats_reset);
 313         }
 314         return 0;
 315 }
 316
 317 static int can_reset_stats_proc_open(struct inode *inode, struct file *file)
 318 {
 319         return single_open(file, can_reset_stats_proc_show, NULL);
 320 }
 321
 322 static const struct file_operations can_reset_stats_proc_fops = {
 323         .owner          = THIS_MODULE,
 324         .open           = can_reset_stats_proc_open,
 325         .read           = seq_read,
 326         .llseek         = seq_lseek,
 327         .release        = single_release,
 328 };
 329
 330 static int can_version_proc_show(struct seq_file *m, void *v)
 331 {
 332         seq_printf(m, "%s\n", CAN_VERSION_STRING);
 333         return 0;
 334 }
 335
 336 static int can_version_proc_open(struct inode *inode, struct file *file)
 337 {
 338         return single_open(file, can_version_proc_show, NULL);
 339 }
 340
 341 static const struct file_operations can_version_proc_fops = {
 342         .owner          = THIS_MODULE,
 343         .open           = can_version_proc_open,
 344         .read           = seq_read,
 345         .llseek         = seq_lseek,
 346         .release        = single_release,
 347 };
 348
 349 static int can_rcvlist_proc_show(struct seq_file *m, void *v)
 350 {
 351         /* double cast to prevent GCC warning */
 352         int idx = (int)(long)m->private;
 353         struct dev_rcv_lists *d;
 354         struct hlist_node *n;
 355
 356         seq_printf(m, "\nreceive list '%s':\n", rx_list_name[idx]);
 357
 358         rcu_read_lock();
 359         hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) {
 360
 361                 if (!hlist_empty(&d->rx[idx])) {
 362                         can_print_recv_banner(m);
 363                         can_print_rcvlist(m, &d->rx[idx], d->dev);
 364                 } else
 365                         seq_printf(m, "  (%s: no entry)\n", DNAME(d->dev));
 366         }
 367         rcu_read_unlock();
 368
 369         seq_putc(m, '\n');
 370         return 0;
 371 }
 372
 373 static int can_rcvlist_proc_open(struct inode *inode, struct file *file)
 374 {
 375         return single_open(file, can_rcvlist_proc_show, PDE(inode)->data);
 376 }
 377
 378 static const struct file_operations can_rcvlist_proc_fops = {
 379         .owner          = THIS_MODULE,
 380         .open           = can_rcvlist_proc_open,
 381         .read           = seq_read,
 382         .llseek         = seq_lseek,
 383         .release        = single_release,
 384 };
 385
 386 static int can_rcvlist_sff_proc_show(struct seq_file *m, void *v)
 387 {
 388         struct dev_rcv_lists *d;
 389         struct hlist_node *n;
 390
 391         /* RX_SFF */
 392         seq_puts(m, "\nreceive list 'rx_sff':\n");
 393
 394         rcu_read_lock();
 395         hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) {
 396                 int i, all_empty = 1;
 397                 /* check wether at least one list is non-empty */
 398                 for (i = 0; i < 0x800; i++)
 399                         if (!hlist_empty(&d->rx_sff[i])) {
 400                                 all_empty = 0;
 401                                 break;
 402                         }
 403
 404                 if (!all_empty) {
 405                         can_print_recv_banner(m);
 406                         for (i = 0; i < 0x800; i++) {
 407                                 if (!hlist_empty(&d->rx_sff[i]))
 408                                         can_print_rcvlist(m, &d->rx_sff[i],
 409                                                           d->dev);
 410                         }
 411                 } else
 412                         seq_printf(m, "  (%s: no entry)\n", DNAME(d->dev));
 413         }
 414         rcu_read_unlock();
 415
 416         seq_putc(m, '\n');
 417         return 0;
 418 }
 419
 420 static int can_rcvlist_sff_proc_open(struct inode *inode, struct file *file)
 421 {
 422         return single_open(file, can_rcvlist_sff_proc_show, NULL);
 423 }
 424
 425 static const struct file_operations can_rcvlist_sff_proc_fops = {
 426         .owner          = THIS_MODULE,
 427         .open           = can_rcvlist_sff_proc_open,
 428         .read           = seq_read,
 429         .llseek         = seq_lseek,
 430         .release        = single_release,
 431 };
 432
 433 /*
 434  * proc utility functions
 435  */
 436
 437 static void can_remove_proc_readentry(const char *name)
 438 {
 439         if (can_dir)
 440                 remove_proc_entry(name, can_dir);
 441 }
 442
 443 /*
 444  * can_init_proc - create main CAN proc directory and procfs entries
 445  */
 446 void can_init_proc(void)
 447 {
 448         /* create /proc/net/can directory */
 449         can_dir = proc_mkdir("can", init_net.proc_net);
 450
 451         if (!can_dir) {
 452                 printk(KERN_INFO "can: failed to create /proc/net/can . "
 453                        "CONFIG_PROC_FS missing?\n");
 454                 return;
 455         }
 456
 457         /* own procfs entries from the AF_CAN core */
 458         pde_version     = proc_create(CAN_PROC_VERSION, 0644, can_dir,
 459                                       &can_version_proc_fops);
 460         pde_stats       = proc_create(CAN_PROC_STATS, 0644, can_dir,
 461                                       &can_stats_proc_fops);
 462         pde_reset_stats = proc_create(CAN_PROC_RESET_STATS, 0644, can_dir,
 463                                       &can_reset_stats_proc_fops);
 464         pde_rcvlist_err = proc_create_data(CAN_PROC_RCVLIST_ERR, 0644, can_dir,
 465                                            &can_rcvlist_proc_fops, (void *)RX_ERR);
 466         pde_rcvlist_all = proc_create_data(CAN_PROC_RCVLIST_ALL, 0644, can_dir,
 467                                            &can_rcvlist_proc_fops, (void *)RX_ALL);
 468         pde_rcvlist_fil = proc_create_data(CAN_PROC_RCVLIST_FIL, 0644, can_dir,
 469                                            &can_rcvlist_proc_fops, (void *)RX_FIL);
 470         pde_rcvlist_inv = proc_create_data(CAN_PROC_RCVLIST_INV, 0644, can_dir,
 471                                            &can_rcvlist_proc_fops, (void *)RX_INV);
 472         pde_rcvlist_eff = proc_create_data(CAN_PROC_RCVLIST_EFF, 0644, can_dir,
 473                                            &can_rcvlist_proc_fops, (void *)RX_EFF);
 474         pde_rcvlist_sff = proc_create(CAN_PROC_RCVLIST_SFF, 0644, can_dir,
 475                                       &can_rcvlist_sff_proc_fops);
 476 }
 477
 478 /*
 479  * can_remove_proc - remove procfs entries and main CAN proc directory
 480  */
 481 void can_remove_proc(void)
 482 {
 483         if (pde_version)
 484                 can_remove_proc_readentry(CAN_PROC_VERSION);
 485
 486         if (pde_stats)
 487                 can_remove_proc_readentry(CAN_PROC_STATS);
 488
 489         if (pde_reset_stats)
 490                 can_remove_proc_readentry(CAN_PROC_RESET_STATS);
 491
 492         if (pde_rcvlist_err)
 493                 can_remove_proc_readentry(CAN_PROC_RCVLIST_ERR);
 494
 495         if (pde_rcvlist_all)
 496                 can_remove_proc_readentry(CAN_PROC_RCVLIST_ALL);
 497
 498         if (pde_rcvlist_fil)
 499                 can_remove_proc_readentry(CAN_PROC_RCVLIST_FIL);
 500
 501         if (pde_rcvlist_inv)
 502                 can_remove_proc_readentry(CAN_PROC_RCVLIST_INV);
 503
 504         if (pde_rcvlist_eff)
 505                 can_remove_proc_readentry(CAN_PROC_RCVLIST_EFF);
 506
 507         if (pde_rcvlist_sff)
 508                 can_remove_proc_readentry(CAN_PROC_RCVLIST_SFF);
 509
 510         if (can_dir)
 511                 proc_net_remove(&init_net, "can");
 512 }