linux/net/can/proc.c
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   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
  66static struct proc_dir_entry *can_dir;
  67static struct proc_dir_entry *pde_version;
  68static struct proc_dir_entry *pde_stats;
  69static struct proc_dir_entry *pde_reset_stats;
  70static struct proc_dir_entry *pde_rcvlist_all;
  71static struct proc_dir_entry *pde_rcvlist_fil;
  72static struct proc_dir_entry *pde_rcvlist_inv;
  73static struct proc_dir_entry *pde_rcvlist_sff;
  74static struct proc_dir_entry *pde_rcvlist_eff;
  75static struct proc_dir_entry *pde_rcvlist_err;
  76
  77static int user_reset;
  78
  79static 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
  91static 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
 109static 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
 129void 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
 199static 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
 231static 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
 244static 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
 324static 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
 349static 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
 360static 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
 394static 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
 444static 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
 456static 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 */
 465void 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 */
 500void 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}
 532