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