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  */
  41
  42 #include <linux/module.h>
  43 #include <linux/proc_fs.h>
  44 #include <linux/list.h>
  45 #include <linux/rcupdate.h>
  46 #include <linux/if_arp.h>
  47 #include <linux/can/core.h>
  48
  49 #include "af_can.h"
  50
  51 /*
  52  * proc filenames for the PF_CAN core
  53  */
  54
  55 #define CAN_PROC_VERSION     "version"
  56 #define CAN_PROC_STATS       "stats"
  57 #define CAN_PROC_RESET_STATS "reset_stats"
  58 #define CAN_PROC_RCVLIST_ALL "rcvlist_all"
  59 #define CAN_PROC_RCVLIST_FIL "rcvlist_fil"
  60 #define CAN_PROC_RCVLIST_INV "rcvlist_inv"
  61 #define CAN_PROC_RCVLIST_SFF "rcvlist_sff"
  62 #define CAN_PROC_RCVLIST_EFF "rcvlist_eff"
  63 #define CAN_PROC_RCVLIST_ERR "rcvlist_err"
  64
  65 static struct proc_dir_entry *can_dir;
  66 static struct proc_dir_entry *pde_version;
  67 static struct proc_dir_entry *pde_stats;
  68 static struct proc_dir_entry *pde_reset_stats;
  69 static struct proc_dir_entry *pde_rcvlist_all;
  70 static struct proc_dir_entry *pde_rcvlist_fil;
  71 static struct proc_dir_entry *pde_rcvlist_inv;
  72 static struct proc_dir_entry *pde_rcvlist_sff;
  73 static struct proc_dir_entry *pde_rcvlist_eff;
  74 static struct proc_dir_entry *pde_rcvlist_err;
  75
  76 static int user_reset;
  77
  78 static const char rx_list_name[][8] = {
  79         [RX_ERR] = "rx_err",
  80         [RX_ALL] = "rx_all",
  81         [RX_FIL] = "rx_fil",
  82         [RX_INV] = "rx_inv",
  83         [RX_EFF] = "rx_eff",
  84 };
  85
  86 /*
  87  * af_can statistics stuff
  88  */
  89
  90 static void can_init_stats(void)
  91 {
  92         /*
  93          * This memset function is called from a timer context (when
  94          * can_stattimer is active which is the default) OR in a process
  95          * context (reading the proc_fs when can_stattimer is disabled).
  96          */
  97         memset(&can_stats, 0, sizeof(can_stats));
  98         can_stats.jiffies_init = jiffies;
  99
 100         can_pstats.stats_reset++;
 101
 102         if (user_reset) {
 103                 user_reset = 0;
 104                 can_pstats.user_reset++;
 105         }
 106 }
 107
 108 static unsigned long calc_rate(unsigned long oldjif, unsigned long newjif,
 109                                unsigned long count)
 110 {
 111         unsigned long rate;
 112
 113         if (oldjif == newjif)
 114                 return 0;
 115
 116         /* see can_stat_update() - this should NEVER happen! */
 117         if (count > (ULONG_MAX / HZ)) {
 118                 printk(KERN_ERR "can: calc_rate: count exceeded! %ld\n",
 119                        count);
 120                 return 99999999;
 121         }
 122
 123         rate = (count * HZ) / (newjif - oldjif);
 124
 125         return rate;
 126 }
 127
 128 void can_stat_update(unsigned long data)
 129 {
 130         unsigned long j = jiffies; /* snapshot */
 131
 132         /* restart counting in timer context on user request */
 133         if (user_reset)
 134                 can_init_stats();
 135
 136         /* restart counting on jiffies overflow */
 137         if (j < can_stats.jiffies_init)
 138                 can_init_stats();
 139
 140         /* prevent overflow in calc_rate() */
 141         if (can_stats.rx_frames > (ULONG_MAX / HZ))
 142                 can_init_stats();
 143
 144         /* prevent overflow in calc_rate() */
 145         if (can_stats.tx_frames > (ULONG_MAX / HZ))
 146                 can_init_stats();
 147
 148         /* matches overflow - very improbable */
 149         if (can_stats.matches > (ULONG_MAX / 100))
 150                 can_init_stats();
 151
 152         /* calc total values */
 153         if (can_stats.rx_frames)
 154                 can_stats.total_rx_match_ratio = (can_stats.matches * 100) /
 155                         can_stats.rx_frames;
 156
 157         can_stats.total_tx_rate = calc_rate(can_stats.jiffies_init, j,
 158                                             can_stats.tx_frames);
 159         can_stats.total_rx_rate = calc_rate(can_stats.jiffies_init, j,
 160                                             can_stats.rx_frames);
 161
 162         /* calc current values */
 163         if (can_stats.rx_frames_delta)
 164                 can_stats.current_rx_match_ratio =
 165                         (can_stats.matches_delta * 100) /
 166                         can_stats.rx_frames_delta;
 167
 168         can_stats.current_tx_rate = calc_rate(0, HZ, can_stats.tx_frames_delta);
 169         can_stats.current_rx_rate = calc_rate(0, HZ, can_stats.rx_frames_delta);
 170
 171         /* check / update maximum values */
 172         if (can_stats.max_tx_rate < can_stats.current_tx_rate)
 173                 can_stats.max_tx_rate = can_stats.current_tx_rate;
 174
 175         if (can_stats.max_rx_rate < can_stats.current_rx_rate)
 176                 can_stats.max_rx_rate = can_stats.current_rx_rate;
 177
 178         if (can_stats.max_rx_match_ratio < can_stats.current_rx_match_ratio)
 179                 can_stats.max_rx_match_ratio = can_stats.current_rx_match_ratio;
 180
 181         /* clear values for 'current rate' calculation */
 182         can_stats.tx_frames_delta = 0;
 183         can_stats.rx_frames_delta = 0;
 184         can_stats.matches_delta   = 0;
 185
 186         /* restart timer (one second) */
 187         mod_timer(&can_stattimer, round_jiffies(jiffies + HZ));
 188 }
 189
 190 /*
 191  * proc read functions
 192  */
 193
 194 static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list,
 195                               struct net_device *dev)
 196 {
 197         struct receiver *r;
 198         struct hlist_node *n;
 199
 200         hlist_for_each_entry_rcu(r, n, rx_list, list) {
 201                 char *fmt = (r->can_id & CAN_EFF_FLAG)?
 202                         "   %-5s  %08x  %08x  %pK  %pK  %8ld  %s\n" :
 203                         "   %-5s     %03x    %08x  %pK  %pK  %8ld  %s\n";
 204
 205                 seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
 206                                 r->func, r->data, r->matches, r->ident);
 207         }
 208 }
 209
 210 static void can_print_recv_banner(struct seq_file *m)
 211 {
 212         /*
 213          *                  can1.  00000000  00000000  00000000
 214          *                 .......          0  tp20
 215          */
 216         seq_puts(m, "  device   can_id   can_mask  function"
 217                         "  userdata   matches  ident\n");
 218 }
 219
 220 static int can_stats_proc_show(struct seq_file *m, void *v)
 221 {
 222         seq_putc(m, '\n');
 223         seq_printf(m, " %8ld transmitted frames (TXF)\n", can_stats.tx_frames);
 224         seq_printf(m, " %8ld received frames (RXF)\n", can_stats.rx_frames);
 225         seq_printf(m, " %8ld matched frames (RXMF)\n", can_stats.matches);
 226
 227         seq_putc(m, '\n');
 228
 229         if (can_stattimer.function == can_stat_update) {
 230                 seq_printf(m, " %8ld %% total match ratio (RXMR)\n",
 231                                 can_stats.total_rx_match_ratio);
 232
 233                 seq_printf(m, " %8ld frames/s total tx rate (TXR)\n",
 234                                 can_stats.total_tx_rate);
 235                 seq_printf(m, " %8ld frames/s total rx rate (RXR)\n",
 236                                 can_stats.total_rx_rate);
 237
 238                 seq_putc(m, '\n');
 239
 240                 seq_printf(m, " %8ld %% current match ratio (CRXMR)\n",
 241                                 can_stats.current_rx_match_ratio);
 242
 243                 seq_printf(m, " %8ld frames/s current tx rate (CTXR)\n",
 244                                 can_stats.current_tx_rate);
 245                 seq_printf(m, " %8ld frames/s current rx rate (CRXR)\n",
 246                                 can_stats.current_rx_rate);
 247
 248                 seq_putc(m, '\n');
 249
 250                 seq_printf(m, " %8ld %% max match ratio (MRXMR)\n",
 251                                 can_stats.max_rx_match_ratio);
 252
 253                 seq_printf(m, " %8ld frames/s max tx rate (MTXR)\n",
 254                                 can_stats.max_tx_rate);
 255                 seq_printf(m, " %8ld frames/s max rx rate (MRXR)\n",
 256                                 can_stats.max_rx_rate);
 257
 258                 seq_putc(m, '\n');
 259         }
 260
 261         seq_printf(m, " %8ld current receive list entries (CRCV)\n",
 262                         can_pstats.rcv_entries);
 263         seq_printf(m, " %8ld maximum receive list entries (MRCV)\n",
 264                         can_pstats.rcv_entries_max);
 265
 266         if (can_pstats.stats_reset)
 267                 seq_printf(m, "\n %8ld statistic resets (STR)\n",
 268                                 can_pstats.stats_reset);
 269
 270         if (can_pstats.user_reset)
 271                 seq_printf(m, " %8ld user statistic resets (USTR)\n",
 272                                 can_pstats.user_reset);
 273
 274         seq_putc(m, '\n');
 275         return 0;
 276 }
 277
 278 static int can_stats_proc_open(struct inode *inode, struct file *file)
 279 {
 280         return single_open(file, can_stats_proc_show, NULL);
 281 }
 282
 283 static const struct file_operations can_stats_proc_fops = {
 284         .owner          = THIS_MODULE,
 285         .open           = can_stats_proc_open,
 286         .read           = seq_read,
 287         .llseek         = seq_lseek,
 288         .release        = single_release,
 289 };
 290
 291 static int can_reset_stats_proc_show(struct seq_file *m, void *v)
 292 {
 293         user_reset = 1;
 294
 295         if (can_stattimer.function == can_stat_update) {
 296                 seq_printf(m, "Scheduled statistic reset #%ld.\n",
 297                                 can_pstats.stats_reset + 1);
 298
 299         } else {
 300                 if (can_stats.jiffies_init != jiffies)
 301                         can_init_stats();
 302
 303                 seq_printf(m, "Performed statistic reset #%ld.\n",
 304                                 can_pstats.stats_reset);
 305         }
 306         return 0;
 307 }
 308
 309 static int can_reset_stats_proc_open(struct inode *inode, struct file *file)
 310 {
 311         return single_open(file, can_reset_stats_proc_show, NULL);
 312 }
 313
 314 static const struct file_operations can_reset_stats_proc_fops = {
 315         .owner          = THIS_MODULE,
 316         .open           = can_reset_stats_proc_open,
 317         .read           = seq_read,
 318         .llseek         = seq_lseek,
 319         .release        = single_release,
 320 };
 321
 322 static int can_version_proc_show(struct seq_file *m, void *v)
 323 {
 324         seq_printf(m, "%s\n", CAN_VERSION_STRING);
 325         return 0;
 326 }
 327
 328 static int can_version_proc_open(struct inode *inode, struct file *file)
 329 {
 330         return single_open(file, can_version_proc_show, NULL);
 331 }
 332
 333 static const struct file_operations can_version_proc_fops = {
 334         .owner          = THIS_MODULE,
 335         .open           = can_version_proc_open,
 336         .read           = seq_read,
 337         .llseek         = seq_lseek,
 338         .release        = single_release,
 339 };
 340
 341 static inline void can_rcvlist_proc_show_one(struct seq_file *m, int idx,
 342                                              struct net_device *dev,
 343                                              struct dev_rcv_lists *d)
 344 {
 345         if (!hlist_empty(&d->rx[idx])) {
 346                 can_print_recv_banner(m);
 347                 can_print_rcvlist(m, &d->rx[idx], dev);
 348         } else
 349                 seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
 350
 351 }
 352
 353 static int can_rcvlist_proc_show(struct seq_file *m, void *v)
 354 {
 355         /* double cast to prevent GCC warning */
 356         int idx = (int)(long)m->private;
 357         struct net_device *dev;
 358         struct dev_rcv_lists *d;
 359
 360         seq_printf(m, "\nreceive list '%s':\n", rx_list_name[idx]);
 361
 362         rcu_read_lock();
 363
 364         /* receive list for 'all' CAN devices (dev == NULL) */
 365         d = &can_rx_alldev_list;
 366         can_rcvlist_proc_show_one(m, idx, NULL, d);
 367
 368         /* receive list for registered CAN devices */
 369         for_each_netdev_rcu(&init_net, dev) {
 370                 if (dev->type == ARPHRD_CAN && dev->ml_priv)
 371                         can_rcvlist_proc_show_one(m, idx, dev, dev->ml_priv);
 372         }
 373
 374         rcu_read_unlock();
 375
 376         seq_putc(m, '\n');
 377         return 0;
 378 }
 379
 380 static int can_rcvlist_proc_open(struct inode *inode, struct file *file)
 381 {
 382         return single_open(file, can_rcvlist_proc_show, PDE(inode)->data);
 383 }
 384
 385 static const struct file_operations can_rcvlist_proc_fops = {
 386         .owner          = THIS_MODULE,
 387         .open           = can_rcvlist_proc_open,
 388         .read           = seq_read,
 389         .llseek         = seq_lseek,
 390         .release        = single_release,
 391 };
 392
 393 static inline void can_rcvlist_sff_proc_show_one(struct seq_file *m,
 394                                                  struct net_device *dev,
 395                                                  struct dev_rcv_lists *d)
 396 {
 397         int i;
 398         int all_empty = 1;
 399
 400         /* check whether at least one list is non-empty */
 401         for (i = 0; i < 0x800; i++)
 402                 if (!hlist_empty(&d->rx_sff[i])) {
 403                         all_empty = 0;
 404                         break;
 405                 }
 406
 407         if (!all_empty) {
 408                 can_print_recv_banner(m);
 409                 for (i = 0; i < 0x800; i++) {
 410                         if (!hlist_empty(&d->rx_sff[i]))
 411                                 can_print_rcvlist(m, &d->rx_sff[i], dev);
 412                 }
 413         } else
 414                 seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
 415 }
 416
 417 static int can_rcvlist_sff_proc_show(struct seq_file *m, void *v)
 418 {
 419         struct net_device *dev;
 420         struct dev_rcv_lists *d;
 421
 422         /* RX_SFF */
 423         seq_puts(m, "\nreceive list 'rx_sff':\n");
 424
 425         rcu_read_lock();
 426
 427         /* sff receive list for 'all' CAN devices (dev == NULL) */
 428         d = &can_rx_alldev_list;
 429         can_rcvlist_sff_proc_show_one(m, NULL, d);
 430
 431         /* sff receive list for registered CAN devices */
 432         for_each_netdev_rcu(&init_net, dev) {
 433                 if (dev->type == ARPHRD_CAN && dev->ml_priv)
 434                         can_rcvlist_sff_proc_show_one(m, dev, dev->ml_priv);
 435         }
 436
 437         rcu_read_unlock();
 438
 439         seq_putc(m, '\n');
 440         return 0;
 441 }
 442
 443 static int can_rcvlist_sff_proc_open(struct inode *inode, struct file *file)
 444 {
 445         return single_open(file, can_rcvlist_sff_proc_show, NULL);
 446 }
 447
 448 static const struct file_operations can_rcvlist_sff_proc_fops = {
 449         .owner          = THIS_MODULE,
 450         .open           = can_rcvlist_sff_proc_open,
 451         .read           = seq_read,
 452         .llseek         = seq_lseek,
 453         .release        = single_release,
 454 };
 455
 456 /*
 457  * proc utility functions
 458  */
 459
 460 static void can_remove_proc_readentry(const char *name)
 461 {
 462         if (can_dir)
 463                 remove_proc_entry(name, can_dir);
 464 }
 465
 466 /*
 467  * can_init_proc - create main CAN proc directory and procfs entries
 468  */
 469 void can_init_proc(void)
 470 {
 471         /* create /proc/net/can directory */
 472         can_dir = proc_mkdir("can", init_net.proc_net);
 473
 474         if (!can_dir) {
 475                 printk(KERN_INFO "can: failed to create /proc/net/can . "
 476                        "CONFIG_PROC_FS missing?\n");
 477                 return;
 478         }
 479
 480         /* own procfs entries from the AF_CAN core */
 481         pde_version     = proc_create(CAN_PROC_VERSION, 0644, can_dir,
 482                                       &can_version_proc_fops);
 483         pde_stats       = proc_create(CAN_PROC_STATS, 0644, can_dir,
 484                                       &can_stats_proc_fops);
 485         pde_reset_stats = proc_create(CAN_PROC_RESET_STATS, 0644, can_dir,
 486                                       &can_reset_stats_proc_fops);
 487         pde_rcvlist_err = proc_create_data(CAN_PROC_RCVLIST_ERR, 0644, can_dir,
 488                                            &can_rcvlist_proc_fops, (void *)RX_ERR);
 489         pde_rcvlist_all = proc_create_data(CAN_PROC_RCVLIST_ALL, 0644, can_dir,
 490                                            &can_rcvlist_proc_fops, (void *)RX_ALL);
 491         pde_rcvlist_fil = proc_create_data(CAN_PROC_RCVLIST_FIL, 0644, can_dir,
 492                                            &can_rcvlist_proc_fops, (void *)RX_FIL);
 493         pde_rcvlist_inv = proc_create_data(CAN_PROC_RCVLIST_INV, 0644, can_dir,
 494                                            &can_rcvlist_proc_fops, (void *)RX_INV);
 495         pde_rcvlist_eff = proc_create_data(CAN_PROC_RCVLIST_EFF, 0644, can_dir,
 496                                            &can_rcvlist_proc_fops, (void *)RX_EFF);
 497         pde_rcvlist_sff = proc_create(CAN_PROC_RCVLIST_SFF, 0644, can_dir,
 498                                       &can_rcvlist_sff_proc_fops);
 499 }
 500
 501 /*
 502  * can_remove_proc - remove procfs entries and main CAN proc directory
 503  */
 504 void can_remove_proc(void)
 505 {
 506         if (pde_version)
 507                 can_remove_proc_readentry(CAN_PROC_VERSION);
 508
 509         if (pde_stats)
 510                 can_remove_proc_readentry(CAN_PROC_STATS);
 511
 512         if (pde_reset_stats)
 513                 can_remove_proc_readentry(CAN_PROC_RESET_STATS);
 514
 515         if (pde_rcvlist_err)
 516                 can_remove_proc_readentry(CAN_PROC_RCVLIST_ERR);
 517
 518         if (pde_rcvlist_all)
 519                 can_remove_proc_readentry(CAN_PROC_RCVLIST_ALL);
 520
 521         if (pde_rcvlist_fil)
 522                 can_remove_proc_readentry(CAN_PROC_RCVLIST_FIL);
 523
 524         if (pde_rcvlist_inv)
 525                 can_remove_proc_readentry(CAN_PROC_RCVLIST_INV);
 526
 527         if (pde_rcvlist_eff)
 528                 can_remove_proc_readentry(CAN_PROC_RCVLIST_EFF);
 529
 530         if (pde_rcvlist_sff)
 531                 can_remove_proc_readentry(CAN_PROC_RCVLIST_SFF);
 532
 533         if (can_dir)
 534                 proc_net_remove(&init_net, "can");
 535 }