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 int can_print_rcvlist(char *page, int len, 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                 len += snprintf(page + len, PAGE_SIZE - len, fmt,
 212                                 DNAME(dev), r->can_id, r->mask,
 213                                 (unsigned long)r->func, (unsigned long)r->data,
 214                                 r->matches, r->ident);
 215
 216                 /* does a typical line fit into the current buffer? */
 217
 218                 /* 100 Bytes before end of buffer */
 219                 if (len > PAGE_SIZE - 100) {
 220                         /* mark output cut off */
 221                         len += snprintf(page + len, PAGE_SIZE - len,
 222                                         "   (..)\n");
 223                         break;
 224                 }
 225         }
 226         rcu_read_unlock();
 227
 228         return len;
 229 }
 230
 231 static int can_print_recv_banner(char *page, int len)
 232 {
 233         /*
 234          *                  can1.  00000000  00000000  00000000
 235          *                 .......          0  tp20
 236          */
 237         len += snprintf(page + len, PAGE_SIZE - len,
 238                         "  device   can_id   can_mask  function"
 239                         "  userdata   matches  ident\n");
 240
 241         return len;
 242 }
 243
 244 static int can_proc_read_stats(char *page, char **start, off_t off,
 245                                int count, int *eof, void *data)
 246 {
 247         int len = 0;
 248
 249         len += snprintf(page + len, PAGE_SIZE - len, "\n");
 250         len += snprintf(page + len, PAGE_SIZE - len,
 251                         " %8ld transmitted frames (TXF)\n",
 252                         can_stats.tx_frames);
 253         len += snprintf(page + len, PAGE_SIZE - len,
 254                         " %8ld received frames (RXF)\n", can_stats.rx_frames);
 255         len += snprintf(page + len, PAGE_SIZE - len,
 256                         " %8ld matched frames (RXMF)\n", can_stats.matches);
 257
 258         len += snprintf(page + len, PAGE_SIZE - len, "\n");
 259
 260         if (can_stattimer.function == can_stat_update) {
 261                 len += snprintf(page + len, PAGE_SIZE - len,
 262                                 " %8ld %% total match ratio (RXMR)\n",
 263                                 can_stats.total_rx_match_ratio);
 264
 265                 len += snprintf(page + len, PAGE_SIZE - len,
 266                                 " %8ld frames/s total tx rate (TXR)\n",
 267                                 can_stats.total_tx_rate);
 268                 len += snprintf(page + len, PAGE_SIZE - len,
 269                                 " %8ld frames/s total rx rate (RXR)\n",
 270                                 can_stats.total_rx_rate);
 271
 272                 len += snprintf(page + len, PAGE_SIZE - len, "\n");
 273
 274                 len += snprintf(page + len, PAGE_SIZE - len,
 275                                 " %8ld %% current match ratio (CRXMR)\n",
 276                                 can_stats.current_rx_match_ratio);
 277
 278                 len += snprintf(page + len, PAGE_SIZE - len,
 279                                 " %8ld frames/s current tx rate (CTXR)\n",
 280                                 can_stats.current_tx_rate);
 281                 len += snprintf(page + len, PAGE_SIZE - len,
 282                                 " %8ld frames/s current rx rate (CRXR)\n",
 283                                 can_stats.current_rx_rate);
 284
 285                 len += snprintf(page + len, PAGE_SIZE - len, "\n");
 286
 287                 len += snprintf(page + len, PAGE_SIZE - len,
 288                                 " %8ld %% max match ratio (MRXMR)\n",
 289                                 can_stats.max_rx_match_ratio);
 290
 291                 len += snprintf(page + len, PAGE_SIZE - len,
 292                                 " %8ld frames/s max tx rate (MTXR)\n",
 293                                 can_stats.max_tx_rate);
 294                 len += snprintf(page + len, PAGE_SIZE - len,
 295                                 " %8ld frames/s max rx rate (MRXR)\n",
 296                                 can_stats.max_rx_rate);
 297
 298                 len += snprintf(page + len, PAGE_SIZE - len, "\n");
 299         }
 300
 301         len += snprintf(page + len, PAGE_SIZE - len,
 302                         " %8ld current receive list entries (CRCV)\n",
 303                         can_pstats.rcv_entries);
 304         len += snprintf(page + len, PAGE_SIZE - len,
 305                         " %8ld maximum receive list entries (MRCV)\n",
 306                         can_pstats.rcv_entries_max);
 307
 308         if (can_pstats.stats_reset)
 309                 len += snprintf(page + len, PAGE_SIZE - len,
 310                                 "\n %8ld statistic resets (STR)\n",
 311                                 can_pstats.stats_reset);
 312
 313         if (can_pstats.user_reset)
 314                 len += snprintf(page + len, PAGE_SIZE - len,
 315                                 " %8ld user statistic resets (USTR)\n",
 316                                 can_pstats.user_reset);
 317
 318         len += snprintf(page + len, PAGE_SIZE - len, "\n");
 319
 320         *eof = 1;
 321         return len;
 322 }
 323
 324 static int can_proc_read_reset_stats(char *page, char **start, off_t off,
 325                                      int count, int *eof, void *data)
 326 {
 327         int len = 0;
 328
 329         user_reset = 1;
 330
 331         if (can_stattimer.function == can_stat_update) {
 332                 len += snprintf(page + len, PAGE_SIZE - len,
 333                                 "Scheduled statistic reset #%ld.\n",
 334                                 can_pstats.stats_reset + 1);
 335
 336         } else {
 337                 if (can_stats.jiffies_init != jiffies)
 338                         can_init_stats();
 339
 340                 len += snprintf(page + len, PAGE_SIZE - len,
 341                                 "Performed statistic reset #%ld.\n",
 342                                 can_pstats.stats_reset);
 343         }
 344
 345         *eof = 1;
 346         return len;
 347 }
 348
 349 static int can_proc_read_version(char *page, char **start, off_t off,
 350                                  int count, int *eof, void *data)
 351 {
 352         int len = 0;
 353
 354         len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
 355                         CAN_VERSION_STRING);
 356         *eof = 1;
 357         return len;
 358 }
 359
 360 static int can_proc_read_rcvlist(char *page, char **start, off_t off,
 361                                  int count, int *eof, void *data)
 362 {
 363         /* double cast to prevent GCC warning */
 364         int idx = (int)(long)data;
 365         int len = 0;
 366         struct dev_rcv_lists *d;
 367         struct hlist_node *n;
 368
 369         len += snprintf(page + len, PAGE_SIZE - len,
 370                         "\nreceive list '%s':\n", rx_list_name[idx]);
 371
 372         rcu_read_lock();
 373         hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) {
 374
 375                 if (!hlist_empty(&d->rx[idx])) {
 376                         len = can_print_recv_banner(page, len);
 377                         len = can_print_rcvlist(page, len, &d->rx[idx], d->dev);
 378                 } else
 379                         len += snprintf(page + len, PAGE_SIZE - len,
 380                                         "  (%s: no entry)\n", DNAME(d->dev));
 381
 382                 /* exit on end of buffer? */
 383                 if (len > PAGE_SIZE - 100)
 384                         break;
 385         }
 386         rcu_read_unlock();
 387
 388         len += snprintf(page + len, PAGE_SIZE - len, "\n");
 389
 390         *eof = 1;
 391         return len;
 392 }
 393
 394 static int can_proc_read_rcvlist_sff(char *page, char **start, off_t off,
 395                                      int count, int *eof, void *data)
 396 {
 397         int len = 0;
 398         struct dev_rcv_lists *d;
 399         struct hlist_node *n;
 400
 401         /* RX_SFF */
 402         len += snprintf(page + len, PAGE_SIZE - len,
 403                         "\nreceive list 'rx_sff':\n");
 404
 405         rcu_read_lock();
 406         hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) {
 407                 int i, all_empty = 1;
 408                 /* check wether at least one list is non-empty */
 409                 for (i = 0; i < 0x800; i++)
 410                         if (!hlist_empty(&d->rx_sff[i])) {
 411                                 all_empty = 0;
 412                                 break;
 413                         }
 414
 415                 if (!all_empty) {
 416                         len = can_print_recv_banner(page, len);
 417                         for (i = 0; i < 0x800; i++) {
 418                                 if (!hlist_empty(&d->rx_sff[i]) &&
 419                                     len < PAGE_SIZE - 100)
 420                                         len = can_print_rcvlist(page, len,
 421                                                                 &d->rx_sff[i],
 422                                                                 d->dev);
 423                         }
 424                 } else
 425                         len += snprintf(page + len, PAGE_SIZE - len,
 426                                         "  (%s: no entry)\n", DNAME(d->dev));
 427
 428                 /* exit on end of buffer? */
 429                 if (len > PAGE_SIZE - 100)
 430                         break;
 431         }
 432         rcu_read_unlock();
 433
 434         len += snprintf(page + len, PAGE_SIZE - len, "\n");
 435
 436         *eof = 1;
 437         return len;
 438 }
 439
 440 /*
 441  * proc utility functions
 442  */
 443
 444 static struct proc_dir_entry *can_create_proc_readentry(const char *name,
 445                                                         mode_t mode,
 446                                                         read_proc_t *read_proc,
 447                                                         void *data)
 448 {
 449         if (can_dir)
 450                 return create_proc_read_entry(name, mode, can_dir, read_proc,
 451                                               data);
 452         else
 453                 return NULL;
 454 }
 455
 456 static void can_remove_proc_readentry(const char *name)
 457 {
 458         if (can_dir)
 459                 remove_proc_entry(name, can_dir);
 460 }
 461
 462 /*
 463  * can_init_proc - create main CAN proc directory and procfs entries
 464  */
 465 void can_init_proc(void)
 466 {
 467         /* create /proc/net/can directory */
 468         can_dir = proc_mkdir("can", init_net.proc_net);
 469
 470         if (!can_dir) {
 471                 printk(KERN_INFO "can: failed to create /proc/net/can . "
 472                        "CONFIG_PROC_FS missing?\n");
 473                 return;
 474         }
 475
 476         /* own procfs entries from the AF_CAN core */
 477         pde_version     = can_create_proc_readentry(CAN_PROC_VERSION, 0644,
 478                                         can_proc_read_version, NULL);
 479         pde_stats       = can_create_proc_readentry(CAN_PROC_STATS, 0644,
 480                                         can_proc_read_stats, NULL);
 481         pde_reset_stats = can_create_proc_readentry(CAN_PROC_RESET_STATS, 0644,
 482                                         can_proc_read_reset_stats, NULL);
 483         pde_rcvlist_err = can_create_proc_readentry(CAN_PROC_RCVLIST_ERR, 0644,
 484                                         can_proc_read_rcvlist, (void *)RX_ERR);
 485         pde_rcvlist_all = can_create_proc_readentry(CAN_PROC_RCVLIST_ALL, 0644,
 486                                         can_proc_read_rcvlist, (void *)RX_ALL);
 487         pde_rcvlist_fil = can_create_proc_readentry(CAN_PROC_RCVLIST_FIL, 0644,
 488                                         can_proc_read_rcvlist, (void *)RX_FIL);
 489         pde_rcvlist_inv = can_create_proc_readentry(CAN_PROC_RCVLIST_INV, 0644,
 490                                         can_proc_read_rcvlist, (void *)RX_INV);
 491         pde_rcvlist_eff = can_create_proc_readentry(CAN_PROC_RCVLIST_EFF, 0644,
 492                                         can_proc_read_rcvlist, (void *)RX_EFF);
 493         pde_rcvlist_sff = can_create_proc_readentry(CAN_PROC_RCVLIST_SFF, 0644,
 494                                         can_proc_read_rcvlist_sff, NULL);
 495 }
 496
 497 /*
 498  * can_remove_proc - remove procfs entries and main CAN proc directory
 499  */
 500 void can_remove_proc(void)
 501 {
 502         if (pde_version)
 503                 can_remove_proc_readentry(CAN_PROC_VERSION);
 504
 505         if (pde_stats)
 506                 can_remove_proc_readentry(CAN_PROC_STATS);
 507
 508         if (pde_reset_stats)
 509                 can_remove_proc_readentry(CAN_PROC_RESET_STATS);
 510
 511         if (pde_rcvlist_err)
 512                 can_remove_proc_readentry(CAN_PROC_RCVLIST_ERR);
 513
 514         if (pde_rcvlist_all)
 515                 can_remove_proc_readentry(CAN_PROC_RCVLIST_ALL);
 516
 517         if (pde_rcvlist_fil)
 518                 can_remove_proc_readentry(CAN_PROC_RCVLIST_FIL);
 519
 520         if (pde_rcvlist_inv)
 521                 can_remove_proc_readentry(CAN_PROC_RCVLIST_INV);
 522
 523         if (pde_rcvlist_eff)
 524                 can_remove_proc_readentry(CAN_PROC_RCVLIST_EFF);
 525
 526         if (pde_rcvlist_sff)
 527                 can_remove_proc_readentry(CAN_PROC_RCVLIST_SFF);
 528
 529         if (can_dir)
 530                 proc_net_remove(&init_net, "can");
 531 }