src/udev/udev-builtin-net_id.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2012 Kay Sievers <kay@vrfy.org>
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 /*
  21  * Predictable network interface device names based on:
  22  *  - firmware/bios-provided index numbers for on-board devices
  23  *  - firmware-provided pci-express hotplug slot index number
  24  *  - physical/geographical location of the hardware
  25  *  - the interface's MAC address
  26  *
  27  * http://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames
  28  *
  29  * Two character prefixes based on the type of interface:
  30  *   en -- ethernet
  31  *   sl -- serial line IP (slip)
  32  *   wl -- wlan
  33  *   ww -- wwan
  34  *
  35  * Type of names:
  36  *   b<number>                             -- BCMA bus core number
  37  *   ccw<name>                             -- CCW bus group name
  38  *   o<index>[d<dev_port>]                 -- on-board device index number
  39  *   s<slot>[f<function>][d<dev_port>]     -- hotplug slot index number
  40  *   x<MAC>                                -- MAC address
  41  *   [P<domain>]p<bus>s<slot>[f<function>][d<dev_port>]
  42  *                                         -- PCI geographical location
  43  *   [P<domain>]p<bus>s<slot>[f<function>][u<port>][..][c<config>][i<interface>]
  44  *                                         -- USB port number chain
  45  *
  46  * All multi-function PCI devices will carry the [f<function>] number in the
  47  * device name, including the function 0 device.
  48  *
  49  * When using PCI geography, The PCI domain is only prepended when it is not 0.
  50  *
  51  * For USB devices the full chain of port numbers of hubs is composed. If the
  52  * name gets longer than the maximum number of 15 characters, the name is not
  53  * exported.
  54  * The usual USB configuration == 1 and interface == 0 values are suppressed.
  55  *
  56  * PCI ethernet card with firmware index "1":
  57  *   ID_NET_NAME_ONBOARD=eno1
  58  *   ID_NET_NAME_ONBOARD_LABEL=Ethernet Port 1
  59  *
  60  * PCI ethernet card in hotplug slot with firmware index number:
  61  *   /sys/devices/pci0000:00/0000:00:1c.3/0000:05:00.0/net/ens1
  62  *   ID_NET_NAME_MAC=enx000000000466
  63  *   ID_NET_NAME_PATH=enp5s0
  64  *   ID_NET_NAME_SLOT=ens1
  65  *
  66  * PCI ethernet multi-function card with 2 ports:
  67  *   /sys/devices/pci0000:00/0000:00:1c.0/0000:02:00.0/net/enp2s0f0
  68  *   ID_NET_NAME_MAC=enx78e7d1ea46da
  69  *   ID_NET_NAME_PATH=enp2s0f0
  70  *   /sys/devices/pci0000:00/0000:00:1c.0/0000:02:00.1/net/enp2s0f1
  71  *   ID_NET_NAME_MAC=enx78e7d1ea46dc
  72  *   ID_NET_NAME_PATH=enp2s0f1
  73  *
  74  * PCI wlan card:
  75  *   /sys/devices/pci0000:00/0000:00:1c.1/0000:03:00.0/net/wlp3s0
  76  *   ID_NET_NAME_MAC=wlx0024d7e31130
  77  *   ID_NET_NAME_PATH=wlp3s0
  78  *
  79  * USB built-in 3G modem:
  80  *   /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4:1.6/net/wwp0s29u1u4i6
  81  *   ID_NET_NAME_MAC=wwx028037ec0200
  82  *   ID_NET_NAME_PATH=wwp0s29u1u4i6
  83  *
  84  * USB Android phone:
  85  *   /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0/net/enp0s29u1u2
  86  *   ID_NET_NAME_MAC=enxd626b3450fb5
  87  *   ID_NET_NAME_PATH=enp0s29u1u2
  88  */
  89
  90 #include <errno.h>
  91 #include <fcntl.h>
  92 #include <net/if.h>
  93 #include <net/if_arp.h>
  94 #include <stdarg.h>
  95 #include <stdio.h>
  96 #include <stdlib.h>
  97 #include <string.h>
  98 #include <unistd.h>
  99 #include <linux/pci_regs.h>
 100
 101 #include "fileio.h"
 102 #include "string-util.h"
 103 #include "udev.h"
 104
 105 enum netname_type{
 106         NET_UNDEF,
 107         NET_PCI,
 108         NET_USB,
 109         NET_BCMA,
 110         NET_VIRTIO,
 111         NET_CCWGROUP,
 112 };
 113
 114 struct netnames {
 115         enum netname_type type;
 116
 117         uint8_t mac[6];
 118         bool mac_valid;
 119
 120         struct udev_device *pcidev;
 121         char pci_slot[IFNAMSIZ];
 122         char pci_path[IFNAMSIZ];
 123         char pci_onboard[IFNAMSIZ];
 124         const char *pci_onboard_label;
 125
 126         char usb_ports[IFNAMSIZ];
 127         char bcma_core[IFNAMSIZ];
 128         char ccw_group[IFNAMSIZ];
 129 };
 130
 131 /* retrieve on-board index number and label from firmware */
 132 static int dev_pci_onboard(struct udev_device *dev, struct netnames *names) {
 133         unsigned dev_port = 0;
 134         size_t l;
 135         char *s;
 136         const char *attr;
 137         int idx;
 138
 139         /* ACPI _DSM  -- device specific method for naming a PCI or PCI Express device */
 140         attr = udev_device_get_sysattr_value(names->pcidev, "acpi_index");
 141         /* SMBIOS type 41 -- Onboard Devices Extended Information */
 142         if (!attr)
 143                 attr = udev_device_get_sysattr_value(names->pcidev, "index");
 144         if (!attr)
 145                 return -ENOENT;
 146
 147         idx = strtoul(attr, NULL, 0);
 148         if (idx <= 0)
 149                 return -EINVAL;
 150
 151         /* kernel provided port index for multiple ports on a single PCI function */
 152         attr = udev_device_get_sysattr_value(dev, "dev_port");
 153         if (attr)
 154                 dev_port = strtol(attr, NULL, 10);
 155
 156         s = names->pci_onboard;
 157         l = sizeof(names->pci_onboard);
 158         l = strpcpyf(&s, l, "o%d", idx);
 159         if (dev_port > 0)
 160                 l = strpcpyf(&s, l, "d%d", dev_port);
 161         if (l == 0)
 162                 names->pci_onboard[0] = '\0';
 163
 164         names->pci_onboard_label = udev_device_get_sysattr_value(names->pcidev, "label");
 165
 166         return 0;
 167 }
 168
 169 /* read the 256 bytes PCI configuration space to check the multi-function bit */
 170 static bool is_pci_multifunction(struct udev_device *dev) {
 171         _cleanup_close_ int fd = -1;
 172         const char *filename;
 173         uint8_t config[64];
 174
 175         filename = strjoina(udev_device_get_syspath(dev), "/config");
 176         fd = open(filename, O_RDONLY | O_CLOEXEC);
 177         if (fd < 0)
 178                 return false;
 179         if (read(fd, &config, sizeof(config)) != sizeof(config))
 180                 return false;
 181
 182         /* bit 0-6 header type, bit 7 multi/single function device */
 183         if ((config[PCI_HEADER_TYPE] & 0x80) != 0)
 184                 return true;
 185
 186         return false;
 187 }
 188
 189 static int dev_pci_slot(struct udev_device *dev, struct netnames *names) {
 190         struct udev *udev = udev_device_get_udev(names->pcidev);
 191         unsigned domain, bus, slot, func, dev_port = 0;
 192         size_t l;
 193         char *s;
 194         const char *attr;
 195         struct udev_device *pci = NULL;
 196         char slots[256], str[256];
 197         _cleanup_closedir_ DIR *dir = NULL;
 198         struct dirent *dent;
 199         int hotplug_slot = 0, err = 0;
 200
 201         if (sscanf(udev_device_get_sysname(names->pcidev), "%x:%x:%x.%u", &domain, &bus, &slot, &func) != 4)
 202                 return -ENOENT;
 203
 204         /* kernel provided port index for multiple ports on a single PCI function */
 205         attr = udev_device_get_sysattr_value(dev, "dev_port");
 206         if (attr)
 207                 dev_port = strtol(attr, NULL, 10);
 208
 209         /* compose a name based on the raw kernel's PCI bus, slot numbers */
 210         s = names->pci_path;
 211         l = sizeof(names->pci_path);
 212         if (domain > 0)
 213                 l = strpcpyf(&s, l, "P%u", domain);
 214         l = strpcpyf(&s, l, "p%us%u", bus, slot);
 215         if (func > 0 || is_pci_multifunction(names->pcidev))
 216                 l = strpcpyf(&s, l, "f%u", func);
 217         if (dev_port > 0)
 218                 l = strpcpyf(&s, l, "d%u", dev_port);
 219         if (l == 0)
 220                 names->pci_path[0] = '\0';
 221
 222         /* ACPI _SUN  -- slot user number */
 223         pci = udev_device_new_from_subsystem_sysname(udev, "subsystem", "pci");
 224         if (!pci) {
 225                 err = -ENOENT;
 226                 goto out;
 227         }
 228         snprintf(slots, sizeof(slots), "%s/slots", udev_device_get_syspath(pci));
 229         dir = opendir(slots);
 230         if (!dir) {
 231                 err = -errno;
 232                 goto out;
 233         }
 234
 235         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 236                 int i;
 237                 char *rest;
 238                 char *address;
 239
 240                 if (dent->d_name[0] == '.')
 241                         continue;
 242                 i = strtol(dent->d_name, &rest, 10);
 243                 if (rest[0] != '\0')
 244                         continue;
 245                 if (i < 1)
 246                         continue;
 247                 snprintf(str, sizeof(str), "%s/%s/address", slots, dent->d_name);
 248                 if (read_one_line_file(str, &address) >= 0) {
 249                         /* match slot address with device by stripping the function */
 250                         if (strneq(address, udev_device_get_sysname(names->pcidev), strlen(address)))
 251                                 hotplug_slot = i;
 252                         free(address);
 253                 }
 254
 255                 if (hotplug_slot > 0)
 256                         break;
 257         }
 258
 259         if (hotplug_slot > 0) {
 260                 s = names->pci_slot;
 261                 l = sizeof(names->pci_slot);
 262                 if (domain > 0)
 263                         l = strpcpyf(&s, l, "P%d", domain);
 264                 l = strpcpyf(&s, l, "s%d", hotplug_slot);
 265                 if (func > 0 || is_pci_multifunction(names->pcidev))
 266                         l = strpcpyf(&s, l, "f%d", func);
 267                 if (dev_port > 0)
 268                         l = strpcpyf(&s, l, "d%d", dev_port);
 269                 if (l == 0)
 270                         names->pci_slot[0] = '\0';
 271         }
 272 out:
 273         udev_device_unref(pci);
 274         return err;
 275 }
 276
 277 static int names_pci(struct udev_device *dev, struct netnames *names) {
 278         struct udev_device *parent;
 279
 280         assert(dev);
 281         assert(names);
 282
 283         parent = udev_device_get_parent(dev);
 284
 285         /* there can only ever be one virtio bus per parent device, so we can
 286            safely ignore any virtio buses. see
 287            <http://lists.linuxfoundation.org/pipermail/virtualization/2015-August/030331.html> */
 288         while (parent && streq_ptr("virtio", udev_device_get_subsystem(parent)))
 289                 parent = udev_device_get_parent(parent);
 290
 291         if (!parent)
 292                 return -ENOENT;
 293
 294         /* check if our direct parent is a PCI device with no other bus in-between */
 295         if (streq_ptr("pci", udev_device_get_subsystem(parent))) {
 296                 names->type = NET_PCI;
 297                 names->pcidev = parent;
 298         } else {
 299                 names->pcidev = udev_device_get_parent_with_subsystem_devtype(dev, "pci", NULL);
 300                 if (!names->pcidev)
 301                         return -ENOENT;
 302         }
 303         dev_pci_onboard(dev, names);
 304         dev_pci_slot(dev, names);
 305         return 0;
 306 }
 307
 308 static int names_usb(struct udev_device *dev, struct netnames *names) {
 309         struct udev_device *usbdev;
 310         char name[256];
 311         char *ports;
 312         char *config;
 313         char *interf;
 314         size_t l;
 315         char *s;
 316
 317         assert(dev);
 318         assert(names);
 319
 320         usbdev = udev_device_get_parent_with_subsystem_devtype(dev, "usb", "usb_interface");
 321         if (!usbdev)
 322                 return -ENOENT;
 323
 324         /* get USB port number chain, configuration, interface */
 325         strscpy(name, sizeof(name), udev_device_get_sysname(usbdev));
 326         s = strchr(name, '-');
 327         if (!s)
 328                 return -EINVAL;
 329         ports = s+1;
 330
 331         s = strchr(ports, ':');
 332         if (!s)
 333                 return -EINVAL;
 334         s[0] = '\0';
 335         config = s+1;
 336
 337         s = strchr(config, '.');
 338         if (!s)
 339                 return -EINVAL;
 340         s[0] = '\0';
 341         interf = s+1;
 342
 343         /* prefix every port number in the chain with "u" */
 344         s = ports;
 345         while ((s = strchr(s, '.')))
 346                 s[0] = 'u';
 347         s = names->usb_ports;
 348         l = strpcpyl(&s, sizeof(names->usb_ports), "u", ports, NULL);
 349
 350         /* append USB config number, suppress the common config == 1 */
 351         if (!streq(config, "1"))
 352                 l = strpcpyl(&s, sizeof(names->usb_ports), "c", config, NULL);
 353
 354         /* append USB interface number, suppress the interface == 0 */
 355         if (!streq(interf, "0"))
 356                 l = strpcpyl(&s, sizeof(names->usb_ports), "i", interf, NULL);
 357         if (l == 0)
 358                 return -ENAMETOOLONG;
 359
 360         names->type = NET_USB;
 361         return 0;
 362 }
 363
 364 static int names_bcma(struct udev_device *dev, struct netnames *names) {
 365         struct udev_device *bcmadev;
 366         unsigned int core;
 367
 368         assert(dev);
 369         assert(names);
 370
 371         bcmadev = udev_device_get_parent_with_subsystem_devtype(dev, "bcma", NULL);
 372         if (!bcmadev)
 373                 return -ENOENT;
 374
 375         /* bus num:core num */
 376         if (sscanf(udev_device_get_sysname(bcmadev), "bcma%*u:%u", &core) != 1)
 377                 return -EINVAL;
 378         /* suppress the common core == 0 */
 379         if (core > 0)
 380                 snprintf(names->bcma_core, sizeof(names->bcma_core), "b%u", core);
 381
 382         names->type = NET_BCMA;
 383         return 0;
 384 }
 385
 386 static int names_ccw(struct  udev_device *dev, struct netnames *names) {
 387         struct udev_device *cdev;
 388         const char *bus_id;
 389         size_t bus_id_len;
 390         int rc;
 391
 392         assert(dev);
 393         assert(names);
 394
 395         /* Retrieve the associated CCW device */
 396         cdev = udev_device_get_parent(dev);
 397         if (!cdev)
 398                 return -ENOENT;
 399
 400         /* Network devices are always grouped CCW devices */
 401         if (!streq_ptr("ccwgroup", udev_device_get_subsystem(cdev)))
 402                 return -ENOENT;
 403
 404         /* Retrieve bus-ID of the grouped CCW device.  The bus-ID uniquely
 405          * identifies the network device on the Linux on System z channel
 406          * subsystem.  Note that the bus-ID contains lowercase characters.
 407          */
 408         bus_id = udev_device_get_sysname(cdev);
 409         if (!bus_id)
 410                 return -ENOENT;
 411
 412         /* Check the length of the bus-ID.  Rely on that the kernel provides
 413          * a correct bus-ID; alternatively, improve this check and parse and
 414          * verify each bus-ID part...
 415          */
 416         bus_id_len = strlen(bus_id);
 417         if (!bus_id_len || bus_id_len < 8 || bus_id_len > 9)
 418                 return -EINVAL;
 419
 420         /* Store the CCW bus-ID for use as network device name */
 421         rc = snprintf(names->ccw_group, sizeof(names->ccw_group), "ccw%s", bus_id);
 422         if (rc >= 0 && rc < (int)sizeof(names->ccw_group))
 423                 names->type = NET_CCWGROUP;
 424         return 0;
 425 }
 426
 427 static int names_mac(struct udev_device *dev, struct netnames *names) {
 428         const char *s;
 429         unsigned int i;
 430         unsigned int a1, a2, a3, a4, a5, a6;
 431
 432         /* check for NET_ADDR_PERM, skip random MAC addresses */
 433         s = udev_device_get_sysattr_value(dev, "addr_assign_type");
 434         if (!s)
 435                 return EXIT_FAILURE;
 436         i = strtoul(s, NULL, 0);
 437         if (i != 0)
 438                 return 0;
 439
 440         s = udev_device_get_sysattr_value(dev, "address");
 441         if (!s)
 442                 return -ENOENT;
 443         if (sscanf(s, "%x:%x:%x:%x:%x:%x", &a1, &a2, &a3, &a4, &a5, &a6) != 6)
 444                 return -EINVAL;
 445
 446         /* skip empty MAC addresses */
 447         if (a1 + a2 + a3 + a4 + a5 + a6 == 0)
 448                 return -EINVAL;
 449
 450         names->mac[0] = a1;
 451         names->mac[1] = a2;
 452         names->mac[2] = a3;
 453         names->mac[3] = a4;
 454         names->mac[4] = a5;
 455         names->mac[5] = a6;
 456         names->mac_valid = true;
 457         return 0;
 458 }
 459
 460 /* IEEE Organizationally Unique Identifier vendor string */
 461 static int ieee_oui(struct udev_device *dev, struct netnames *names, bool test) {
 462         char str[32];
 463
 464         if (!names->mac_valid)
 465                 return -ENOENT;
 466         /* skip commonly misused 00:00:00 (Xerox) prefix */
 467         if (memcmp(names->mac, "\0\0\0", 3) == 0)
 468                 return -EINVAL;
 469         snprintf(str, sizeof(str), "OUI:%02X%02X%02X%02X%02X%02X",
 470                  names->mac[0], names->mac[1], names->mac[2],
 471                  names->mac[3], names->mac[4], names->mac[5]);
 472         udev_builtin_hwdb_lookup(dev, NULL, str, NULL, test);
 473         return 0;
 474 }
 475
 476 static int builtin_net_id(struct udev_device *dev, int argc, char *argv[], bool test) {
 477         const char *s;
 478         const char *p;
 479         unsigned int i;
 480         const char *devtype;
 481         const char *prefix = "en";
 482         struct netnames names = {};
 483         int err;
 484
 485         /* handle only ARPHRD_ETHER and ARPHRD_SLIP devices */
 486         s = udev_device_get_sysattr_value(dev, "type");
 487         if (!s)
 488                 return EXIT_FAILURE;
 489         i = strtoul(s, NULL, 0);
 490         switch (i) {
 491         case ARPHRD_ETHER:
 492                 prefix = "en";
 493                 break;
 494         case ARPHRD_SLIP:
 495                 prefix = "sl";
 496                 break;
 497         default:
 498                 return 0;
 499         }
 500
 501         /* skip stacked devices, like VLANs, ... */
 502         s = udev_device_get_sysattr_value(dev, "ifindex");
 503         if (!s)
 504                 return EXIT_FAILURE;
 505         p = udev_device_get_sysattr_value(dev, "iflink");
 506         if (!p)
 507                 return EXIT_FAILURE;
 508         if (!streq(s, p))
 509                 return 0;
 510
 511         devtype = udev_device_get_devtype(dev);
 512         if (devtype) {
 513                 if (streq("wlan", devtype))
 514                         prefix = "wl";
 515                 else if (streq("wwan", devtype))
 516                         prefix = "ww";
 517         }
 518
 519         err = names_mac(dev, &names);
 520         if (err >= 0 && names.mac_valid) {
 521                 char str[IFNAMSIZ];
 522
 523                 snprintf(str, sizeof(str), "%sx%02x%02x%02x%02x%02x%02x", prefix,
 524                          names.mac[0], names.mac[1], names.mac[2],
 525                          names.mac[3], names.mac[4], names.mac[5]);
 526                 udev_builtin_add_property(dev, test, "ID_NET_NAME_MAC", str);
 527
 528                 ieee_oui(dev, &names, test);
 529         }
 530
 531         /* get path names for Linux on System z network devices */
 532         err = names_ccw(dev, &names);
 533         if (err >= 0 && names.type == NET_CCWGROUP) {
 534                 char str[IFNAMSIZ];
 535
 536                 if (snprintf(str, sizeof(str), "%s%s", prefix, names.ccw_group) < (int)sizeof(str))
 537                         udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
 538                 goto out;
 539         }
 540
 541         /* get PCI based path names, we compose only PCI based paths */
 542         err = names_pci(dev, &names);
 543         if (err < 0)
 544                 goto out;
 545
 546         /* plain PCI device */
 547         if (names.type == NET_PCI) {
 548                 char str[IFNAMSIZ];
 549
 550                 if (names.pci_onboard[0])
 551                         if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_onboard) < (int)sizeof(str))
 552                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_ONBOARD", str);
 553
 554                 if (names.pci_onboard_label)
 555                         if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_onboard_label) < (int)sizeof(str))
 556                                 udev_builtin_add_property(dev, test, "ID_NET_LABEL_ONBOARD", str);
 557
 558                 if (names.pci_path[0])
 559                         if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_path) < (int)sizeof(str))
 560                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
 561
 562                 if (names.pci_slot[0])
 563                         if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_slot) < (int)sizeof(str))
 564                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
 565                 goto out;
 566         }
 567
 568         /* USB device */
 569         err = names_usb(dev, &names);
 570         if (err >= 0 && names.type == NET_USB) {
 571                 char str[IFNAMSIZ];
 572
 573                 if (names.pci_path[0])
 574                         if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_path, names.usb_ports) < (int)sizeof(str))
 575                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
 576
 577                 if (names.pci_slot[0])
 578                         if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_slot, names.usb_ports) < (int)sizeof(str))
 579                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
 580                 goto out;
 581         }
 582
 583         /* Broadcom bus */
 584         err = names_bcma(dev, &names);
 585         if (err >= 0 && names.type == NET_BCMA) {
 586                 char str[IFNAMSIZ];
 587
 588                 if (names.pci_path[0])
 589                         if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_path, names.bcma_core) < (int)sizeof(str))
 590                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
 591
 592                 if (names.pci_slot[0])
 593                         if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_slot, names.bcma_core) < (int)sizeof(str))
 594                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
 595                 goto out;
 596         }
 597 out:
 598         return EXIT_SUCCESS;
 599 }
 600
 601 const struct udev_builtin udev_builtin_net_id = {
 602         .name = "net_id",
 603         .cmd = builtin_net_id,
 604         .help = "Network device properties",
 605 };