net/core/net-sysfs.c

   1 /*
   2  * net-sysfs.c - network device class and attributes
   3  *
   4  * Copyright (c) 2003 Stephen Hemminger <shemminger@osdl.org>
   5  *
   6  *      This program is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU General Public License
   8  *      as published by the Free Software Foundation; either version
   9  *      2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/capability.h>
  13 #include <linux/kernel.h>
  14 #include <linux/netdevice.h>
  15 #include <linux/if_arp.h>
  16 #include <net/sock.h>
  17 #include <linux/rtnetlink.h>
  18 #include <linux/wireless.h>
  19 #include <net/wext.h>
  20
  21 #include "net-sysfs.h"
  22
  23 #ifdef CONFIG_SYSFS
  24 static const char fmt_hex[] = "%#x\n";
  25 static const char fmt_long_hex[] = "%#lx\n";
  26 static const char fmt_dec[] = "%d\n";
  27 static const char fmt_ulong[] = "%lu\n";
  28
  29 static inline int dev_isalive(const struct net_device *dev)
  30 {
  31         return dev->reg_state <= NETREG_REGISTERED;
  32 }
  33
  34 /* use same locking rules as GIF* ioctl's */
  35 static ssize_t netdev_show(const struct device *dev,
  36                            struct device_attribute *attr, char *buf,
  37                            ssize_t (*format)(const struct net_device *, char *))
  38 {
  39         struct net_device *net = to_net_dev(dev);
  40         ssize_t ret = -EINVAL;
  41
  42         read_lock(&dev_base_lock);
  43         if (dev_isalive(net))
  44                 ret = (*format)(net, buf);
  45         read_unlock(&dev_base_lock);
  46
  47         return ret;
  48 }
  49
  50 /* generate a show function for simple field */
  51 #define NETDEVICE_SHOW(field, format_string)                            \
  52 static ssize_t format_##field(const struct net_device *net, char *buf)  \
  53 {                                                                       \
  54         return sprintf(buf, format_string, net->field);                 \
  55 }                                                                       \
  56 static ssize_t show_##field(struct device *dev,                         \
  57                             struct device_attribute *attr, char *buf)   \
  58 {                                                                       \
  59         return netdev_show(dev, attr, buf, format_##field);             \
  60 }
  61
  62
  63 /* use same locking and permission rules as SIF* ioctl's */
  64 static ssize_t netdev_store(struct device *dev, struct device_attribute *attr,
  65                             const char *buf, size_t len,
  66                             int (*set)(struct net_device *, unsigned long))
  67 {
  68         struct net_device *net = to_net_dev(dev);
  69         char *endp;
  70         unsigned long new;
  71         int ret = -EINVAL;
  72
  73         if (!capable(CAP_NET_ADMIN))
  74                 return -EPERM;
  75
  76         new = simple_strtoul(buf, &endp, 0);
  77         if (endp == buf)
  78                 goto err;
  79
  80         if (!rtnl_trylock())
  81                 return restart_syscall();
  82
  83         if (dev_isalive(net)) {
  84                 if ((ret = (*set)(net, new)) == 0)
  85                         ret = len;
  86         }
  87         rtnl_unlock();
  88  err:
  89         return ret;
  90 }
  91
  92 NETDEVICE_SHOW(dev_id, fmt_hex);
  93 NETDEVICE_SHOW(addr_len, fmt_dec);
  94 NETDEVICE_SHOW(iflink, fmt_dec);
  95 NETDEVICE_SHOW(ifindex, fmt_dec);
  96 NETDEVICE_SHOW(features, fmt_long_hex);
  97 NETDEVICE_SHOW(type, fmt_dec);
  98 NETDEVICE_SHOW(link_mode, fmt_dec);
  99
 100 /* use same locking rules as GIFHWADDR ioctl's */
 101 static ssize_t show_address(struct device *dev, struct device_attribute *attr,
 102                             char *buf)
 103 {
 104         struct net_device *net = to_net_dev(dev);
 105         ssize_t ret = -EINVAL;
 106
 107         read_lock(&dev_base_lock);
 108         if (dev_isalive(net))
 109                 ret = sysfs_format_mac(buf, net->dev_addr, net->addr_len);
 110         read_unlock(&dev_base_lock);
 111         return ret;
 112 }
 113
 114 static ssize_t show_broadcast(struct device *dev,
 115                             struct device_attribute *attr, char *buf)
 116 {
 117         struct net_device *net = to_net_dev(dev);
 118         if (dev_isalive(net))
 119                 return sysfs_format_mac(buf, net->broadcast, net->addr_len);
 120         return -EINVAL;
 121 }
 122
 123 static ssize_t show_carrier(struct device *dev,
 124                             struct device_attribute *attr, char *buf)
 125 {
 126         struct net_device *netdev = to_net_dev(dev);
 127         if (netif_running(netdev)) {
 128                 return sprintf(buf, fmt_dec, !!netif_carrier_ok(netdev));
 129         }
 130         return -EINVAL;
 131 }
 132
 133 static ssize_t show_dormant(struct device *dev,
 134                             struct device_attribute *attr, char *buf)
 135 {
 136         struct net_device *netdev = to_net_dev(dev);
 137
 138         if (netif_running(netdev))
 139                 return sprintf(buf, fmt_dec, !!netif_dormant(netdev));
 140
 141         return -EINVAL;
 142 }
 143
 144 static const char *const operstates[] = {
 145         "unknown",
 146         "notpresent", /* currently unused */
 147         "down",
 148         "lowerlayerdown",
 149         "testing", /* currently unused */
 150         "dormant",
 151         "up"
 152 };
 153
 154 static ssize_t show_operstate(struct device *dev,
 155                               struct device_attribute *attr, char *buf)
 156 {
 157         const struct net_device *netdev = to_net_dev(dev);
 158         unsigned char operstate;
 159
 160         read_lock(&dev_base_lock);
 161         operstate = netdev->operstate;
 162         if (!netif_running(netdev))
 163                 operstate = IF_OPER_DOWN;
 164         read_unlock(&dev_base_lock);
 165
 166         if (operstate >= ARRAY_SIZE(operstates))
 167                 return -EINVAL; /* should not happen */
 168
 169         return sprintf(buf, "%s\n", operstates[operstate]);
 170 }
 171
 172 /* read-write attributes */
 173 NETDEVICE_SHOW(mtu, fmt_dec);
 174
 175 static int change_mtu(struct net_device *net, unsigned long new_mtu)
 176 {
 177         return dev_set_mtu(net, (int) new_mtu);
 178 }
 179
 180 static ssize_t store_mtu(struct device *dev, struct device_attribute *attr,
 181                          const char *buf, size_t len)
 182 {
 183         return netdev_store(dev, attr, buf, len, change_mtu);
 184 }
 185
 186 NETDEVICE_SHOW(flags, fmt_hex);
 187
 188 static int change_flags(struct net_device *net, unsigned long new_flags)
 189 {
 190         return dev_change_flags(net, (unsigned) new_flags);
 191 }
 192
 193 static ssize_t store_flags(struct device *dev, struct device_attribute *attr,
 194                            const char *buf, size_t len)
 195 {
 196         return netdev_store(dev, attr, buf, len, change_flags);
 197 }
 198
 199 NETDEVICE_SHOW(tx_queue_len, fmt_ulong);
 200
 201 static int change_tx_queue_len(struct net_device *net, unsigned long new_len)
 202 {
 203         net->tx_queue_len = new_len;
 204         return 0;
 205 }
 206
 207 static ssize_t store_tx_queue_len(struct device *dev,
 208                                   struct device_attribute *attr,
 209                                   const char *buf, size_t len)
 210 {
 211         return netdev_store(dev, attr, buf, len, change_tx_queue_len);
 212 }
 213
 214 static ssize_t store_ifalias(struct device *dev, struct device_attribute *attr,
 215                              const char *buf, size_t len)
 216 {
 217         struct net_device *netdev = to_net_dev(dev);
 218         size_t count = len;
 219         ssize_t ret;
 220
 221         if (!capable(CAP_NET_ADMIN))
 222                 return -EPERM;
 223
 224         /* ignore trailing newline */
 225         if (len >  0 && buf[len - 1] == '\n')
 226                 --count;
 227
 228         if (!rtnl_trylock())
 229                 return restart_syscall();
 230         ret = dev_set_alias(netdev, buf, count);
 231         rtnl_unlock();
 232
 233         return ret < 0 ? ret : len;
 234 }
 235
 236 static ssize_t show_ifalias(struct device *dev,
 237                             struct device_attribute *attr, char *buf)
 238 {
 239         const struct net_device *netdev = to_net_dev(dev);
 240         ssize_t ret = 0;
 241
 242         if (!rtnl_trylock())
 243                 return restart_syscall();
 244         if (netdev->ifalias)
 245                 ret = sprintf(buf, "%s\n", netdev->ifalias);
 246         rtnl_unlock();
 247         return ret;
 248 }
 249
 250 static struct device_attribute net_class_attributes[] = {
 251         __ATTR(addr_len, S_IRUGO, show_addr_len, NULL),
 252         __ATTR(dev_id, S_IRUGO, show_dev_id, NULL),
 253         __ATTR(ifalias, S_IRUGO | S_IWUSR, show_ifalias, store_ifalias),
 254         __ATTR(iflink, S_IRUGO, show_iflink, NULL),
 255         __ATTR(ifindex, S_IRUGO, show_ifindex, NULL),
 256         __ATTR(features, S_IRUGO, show_features, NULL),
 257         __ATTR(type, S_IRUGO, show_type, NULL),
 258         __ATTR(link_mode, S_IRUGO, show_link_mode, NULL),
 259         __ATTR(address, S_IRUGO, show_address, NULL),
 260         __ATTR(broadcast, S_IRUGO, show_broadcast, NULL),
 261         __ATTR(carrier, S_IRUGO, show_carrier, NULL),
 262         __ATTR(dormant, S_IRUGO, show_dormant, NULL),
 263         __ATTR(operstate, S_IRUGO, show_operstate, NULL),
 264         __ATTR(mtu, S_IRUGO | S_IWUSR, show_mtu, store_mtu),
 265         __ATTR(flags, S_IRUGO | S_IWUSR, show_flags, store_flags),
 266         __ATTR(tx_queue_len, S_IRUGO | S_IWUSR, show_tx_queue_len,
 267                store_tx_queue_len),
 268         {}
 269 };
 270
 271 /* Show a given an attribute in the statistics group */
 272 static ssize_t netstat_show(const struct device *d,
 273                             struct device_attribute *attr, char *buf,
 274                             unsigned long offset)
 275 {
 276         struct net_device *dev = to_net_dev(d);
 277         ssize_t ret = -EINVAL;
 278
 279         WARN_ON(offset > sizeof(struct net_device_stats) ||
 280                         offset % sizeof(unsigned long) != 0);
 281
 282         read_lock(&dev_base_lock);
 283         if (dev_isalive(dev)) {
 284                 const struct net_device_stats *stats = dev_get_stats(dev);
 285                 ret = sprintf(buf, fmt_ulong,
 286                               *(unsigned long *)(((u8 *) stats) + offset));
 287         }
 288         read_unlock(&dev_base_lock);
 289         return ret;
 290 }
 291
 292 /* generate a read-only statistics attribute */
 293 #define NETSTAT_ENTRY(name)                                             \
 294 static ssize_t show_##name(struct device *d,                            \
 295                            struct device_attribute *attr, char *buf)    \
 296 {                                                                       \
 297         return netstat_show(d, attr, buf,                               \
 298                             offsetof(struct net_device_stats, name));   \
 299 }                                                                       \
 300 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
 301
 302 NETSTAT_ENTRY(rx_packets);
 303 NETSTAT_ENTRY(tx_packets);
 304 NETSTAT_ENTRY(rx_bytes);
 305 NETSTAT_ENTRY(tx_bytes);
 306 NETSTAT_ENTRY(rx_errors);
 307 NETSTAT_ENTRY(tx_errors);
 308 NETSTAT_ENTRY(rx_dropped);
 309 NETSTAT_ENTRY(tx_dropped);
 310 NETSTAT_ENTRY(multicast);
 311 NETSTAT_ENTRY(collisions);
 312 NETSTAT_ENTRY(rx_length_errors);
 313 NETSTAT_ENTRY(rx_over_errors);
 314 NETSTAT_ENTRY(rx_crc_errors);
 315 NETSTAT_ENTRY(rx_frame_errors);
 316 NETSTAT_ENTRY(rx_fifo_errors);
 317 NETSTAT_ENTRY(rx_missed_errors);
 318 NETSTAT_ENTRY(tx_aborted_errors);
 319 NETSTAT_ENTRY(tx_carrier_errors);
 320 NETSTAT_ENTRY(tx_fifo_errors);
 321 NETSTAT_ENTRY(tx_heartbeat_errors);
 322 NETSTAT_ENTRY(tx_window_errors);
 323 NETSTAT_ENTRY(rx_compressed);
 324 NETSTAT_ENTRY(tx_compressed);
 325
 326 static struct attribute *netstat_attrs[] = {
 327         &dev_attr_rx_packets.attr,
 328         &dev_attr_tx_packets.attr,
 329         &dev_attr_rx_bytes.attr,
 330         &dev_attr_tx_bytes.attr,
 331         &dev_attr_rx_errors.attr,
 332         &dev_attr_tx_errors.attr,
 333         &dev_attr_rx_dropped.attr,
 334         &dev_attr_tx_dropped.attr,
 335         &dev_attr_multicast.attr,
 336         &dev_attr_collisions.attr,
 337         &dev_attr_rx_length_errors.attr,
 338         &dev_attr_rx_over_errors.attr,
 339         &dev_attr_rx_crc_errors.attr,
 340         &dev_attr_rx_frame_errors.attr,
 341         &dev_attr_rx_fifo_errors.attr,
 342         &dev_attr_rx_missed_errors.attr,
 343         &dev_attr_tx_aborted_errors.attr,
 344         &dev_attr_tx_carrier_errors.attr,
 345         &dev_attr_tx_fifo_errors.attr,
 346         &dev_attr_tx_heartbeat_errors.attr,
 347         &dev_attr_tx_window_errors.attr,
 348         &dev_attr_rx_compressed.attr,
 349         &dev_attr_tx_compressed.attr,
 350         NULL
 351 };
 352
 353
 354 static struct attribute_group netstat_group = {
 355         .name  = "statistics",
 356         .attrs  = netstat_attrs,
 357 };
 358
 359 #ifdef CONFIG_WIRELESS_EXT_SYSFS
 360 /* helper function that does all the locking etc for wireless stats */
 361 static ssize_t wireless_show(struct device *d, char *buf,
 362                              ssize_t (*format)(const struct iw_statistics *,
 363                                                char *))
 364 {
 365         struct net_device *dev = to_net_dev(d);
 366         const struct iw_statistics *iw;
 367         ssize_t ret = -EINVAL;
 368
 369         if (!rtnl_trylock())
 370                 return restart_syscall();
 371         if (dev_isalive(dev)) {
 372                 iw = get_wireless_stats(dev);
 373                 if (iw)
 374                         ret = (*format)(iw, buf);
 375         }
 376         rtnl_unlock();
 377
 378         return ret;
 379 }
 380
 381 /* show function template for wireless fields */
 382 #define WIRELESS_SHOW(name, field, format_string)                       \
 383 static ssize_t format_iw_##name(const struct iw_statistics *iw, char *buf) \
 384 {                                                                       \
 385         return sprintf(buf, format_string, iw->field);                  \
 386 }                                                                       \
 387 static ssize_t show_iw_##name(struct device *d,                         \
 388                               struct device_attribute *attr, char *buf) \
 389 {                                                                       \
 390         return wireless_show(d, buf, format_iw_##name);                 \
 391 }                                                                       \
 392 static DEVICE_ATTR(name, S_IRUGO, show_iw_##name, NULL)
 393
 394 WIRELESS_SHOW(status, status, fmt_hex);
 395 WIRELESS_SHOW(link, qual.qual, fmt_dec);
 396 WIRELESS_SHOW(level, qual.level, fmt_dec);
 397 WIRELESS_SHOW(noise, qual.noise, fmt_dec);
 398 WIRELESS_SHOW(nwid, discard.nwid, fmt_dec);
 399 WIRELESS_SHOW(crypt, discard.code, fmt_dec);
 400 WIRELESS_SHOW(fragment, discard.fragment, fmt_dec);
 401 WIRELESS_SHOW(misc, discard.misc, fmt_dec);
 402 WIRELESS_SHOW(retries, discard.retries, fmt_dec);
 403 WIRELESS_SHOW(beacon, miss.beacon, fmt_dec);
 404
 405 static struct attribute *wireless_attrs[] = {
 406         &dev_attr_status.attr,
 407         &dev_attr_link.attr,
 408         &dev_attr_level.attr,
 409         &dev_attr_noise.attr,
 410         &dev_attr_nwid.attr,
 411         &dev_attr_crypt.attr,
 412         &dev_attr_fragment.attr,
 413         &dev_attr_retries.attr,
 414         &dev_attr_misc.attr,
 415         &dev_attr_beacon.attr,
 416         NULL
 417 };
 418
 419 static struct attribute_group wireless_group = {
 420         .name = "wireless",
 421         .attrs = wireless_attrs,
 422 };
 423 #endif
 424
 425 #endif /* CONFIG_SYSFS */
 426
 427 #ifdef CONFIG_HOTPLUG
 428 static int netdev_uevent(struct device *d, struct kobj_uevent_env *env)
 429 {
 430         struct net_device *dev = to_net_dev(d);
 431         int retval;
 432
 433         if (!net_eq(dev_net(dev), &init_net))
 434                 return 0;
 435
 436         /* pass interface to uevent. */
 437         retval = add_uevent_var(env, "INTERFACE=%s", dev->name);
 438         if (retval)
 439                 goto exit;
 440
 441         /* pass ifindex to uevent.
 442          * ifindex is useful as it won't change (interface name may change)
 443          * and is what RtNetlink uses natively. */
 444         retval = add_uevent_var(env, "IFINDEX=%d", dev->ifindex);
 445
 446 exit:
 447         return retval;
 448 }
 449 #endif
 450
 451 /*
 452  *      netdev_release -- destroy and free a dead device.
 453  *      Called when last reference to device kobject is gone.
 454  */
 455 static void netdev_release(struct device *d)
 456 {
 457         struct net_device *dev = to_net_dev(d);
 458
 459         BUG_ON(dev->reg_state != NETREG_RELEASED);
 460
 461         kfree(dev->ifalias);
 462         kfree((char *)dev - dev->padded);
 463 }
 464
 465 static struct class net_class = {
 466         .name = "net",
 467         .dev_release = netdev_release,
 468 #ifdef CONFIG_SYSFS
 469         .dev_attrs = net_class_attributes,
 470 #endif /* CONFIG_SYSFS */
 471 #ifdef CONFIG_HOTPLUG
 472         .dev_uevent = netdev_uevent,
 473 #endif
 474 };
 475
 476 /* Delete sysfs entries but hold kobject reference until after all
 477  * netdev references are gone.
 478  */
 479 void netdev_unregister_kobject(struct net_device * net)
 480 {
 481         struct device *dev = &(net->dev);
 482
 483         kobject_get(&dev->kobj);
 484
 485         if (dev_net(net) != &init_net)
 486                 return;
 487
 488         device_del(dev);
 489 }
 490
 491 /* Create sysfs entries for network device. */
 492 int netdev_register_kobject(struct net_device *net)
 493 {
 494         struct device *dev = &(net->dev);
 495         const struct attribute_group **groups = net->sysfs_groups;
 496
 497         dev->class = &net_class;
 498         dev->platform_data = net;
 499         dev->groups = groups;
 500
 501         dev_set_name(dev, "%s", net->name);
 502
 503 #ifdef CONFIG_SYSFS
 504         *groups++ = &netstat_group;
 505
 506 #ifdef CONFIG_WIRELESS_EXT_SYSFS
 507         if (net->wireless_handlers || net->ieee80211_ptr)
 508                 *groups++ = &wireless_group;
 509 #endif
 510 #endif /* CONFIG_SYSFS */
 511
 512         if (dev_net(net) != &init_net)
 513                 return 0;
 514
 515         return device_add(dev);
 516 }
 517
 518 int netdev_class_create_file(struct class_attribute *class_attr)
 519 {
 520         return class_create_file(&net_class, class_attr);
 521 }
 522
 523 void netdev_class_remove_file(struct class_attribute *class_attr)
 524 {
 525         class_remove_file(&net_class, class_attr);
 526 }
 527
 528 EXPORT_SYMBOL(netdev_class_create_file);
 529 EXPORT_SYMBOL(netdev_class_remove_file);
 530
 531 void netdev_initialize_kobject(struct net_device *net)
 532 {
 533         struct device *device = &(net->dev);
 534         device_initialize(device);
 535 }
 536
 537 int netdev_kobject_init(void)
 538 {
 539         return class_register(&net_class);
 540 }