2 This file is part of systemd.
4 Copyright 2012 Kay Sievers <kay@vrfy.org>
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.
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.
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/>.
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
27 * Two character prefixes based on the type of interface:
33 * o<index> -- on-board device index number
34 * s<slot>[f<function>][d<dev_id>] -- hotplug slot index number
35 * x<MAC> -- MAC address
36 * p<bus>s<slot>[f<function>][d<dev_id>] -- PCI geographical location
37 * p<bus>s<slot>[f<function>][u<port>][..][c<config>][i<interface>]
38 * -- USB port number chain
40 * All multi-function PCI devices will carry the [f<function>] number in the
41 * device name, including the function 0 device.
43 * For USB devices the full chain of port numbers of hubs is composed. If the
44 * name gets longer than the maximum number of 15 characters, the name is not
46 * The usual USB configuration == 1 and interface == 0 values are suppressed.
48 * PCI ethernet card with firmware index "1":
49 * ID_NET_NAME_ONBOARD=eno1
50 * ID_NET_NAME_ONBOARD_LABEL=Ethernet Port 1
52 * PCI ethernet card in hotplug slot with firmware index number:
53 * /sys/devices/pci0000:00/0000:00:1c.3/0000:05:00.0/net/ens1
54 * ID_NET_NAME_MAC=enx000000000466
55 * ID_NET_NAME_PATH=enp5s0
56 * ID_NET_NAME_SLOT=ens1
58 * PCI ethernet multi-function card with 2 ports:
59 * /sys/devices/pci0000:00/0000:00:1c.0/0000:02:00.0/net/enp2s0f0
60 * ID_NET_NAME_MAC=enx78e7d1ea46da
61 * ID_NET_NAME_PATH=enp2s0f0
62 * /sys/devices/pci0000:00/0000:00:1c.0/0000:02:00.1/net/enp2s0f1
63 * ID_NET_NAME_MAC=enx78e7d1ea46dc
64 * ID_NET_NAME_PATH=enp2s0f1
67 * /sys/devices/pci0000:00/0000:00:1c.1/0000:03:00.0/net/wlp3s0
68 * ID_NET_NAME_MAC=wlx0024d7e31130
69 * ID_NET_NAME_PATH=wlp3s0
71 * USB built-in 3G modem:
72 * /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4:1.6/net/wwp0s29u1u4i6
73 * ID_NET_NAME_MAC=wwx028037ec0200
74 * ID_NET_NAME_PATH=wwp0s29u1u4i6
77 * /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0/net/enp0s29u1u2
78 * ID_NET_NAME_MAC=enxd626b3450fb5
79 * ID_NET_NAME_PATH=enp0s29u1u2
89 #include <linux/pci_regs.h>
100 enum netname_type type;
105 struct udev_device *pcidev;
106 char pci_slot[IFNAMSIZ];
107 char pci_path[IFNAMSIZ];
108 char pci_onboard[IFNAMSIZ];
109 const char *pci_onboard_label;
111 struct udev_device *usbdev;
112 char usb_ports[IFNAMSIZ];
115 /* retrieve on-board index number and label from firmware */
116 static int dev_pci_onboard(struct udev_device *dev, struct netnames *names) {
120 /* ACPI _DSM -- device specific method for naming a PCI or PCI Express device */
121 index = udev_device_get_sysattr_value(names->pcidev, "acpi_index");
122 /* SMBIOS type 41 -- Onboard Devices Extended Information */
124 index = udev_device_get_sysattr_value(names->pcidev, "index");
127 idx = strtoul(index, NULL, 0);
130 snprintf(names->pci_onboard, sizeof(names->pci_onboard), "o%d", idx);
132 names->pci_onboard_label = udev_device_get_sysattr_value(names->pcidev, "label");
136 /* read the 256 bytes PCI configuration space to check the multi-function bit */
137 static bool is_pci_multifunction(struct udev_device *dev) {
143 snprintf(filename, sizeof(filename), "%s/config", udev_device_get_syspath(dev));
144 f = fopen(filename, "re");
147 if (fread(&config, sizeof(config), 1, f) != 1)
150 /* bit 0-6 header type, bit 7 multi/single function device */
151 if ((config[PCI_HEADER_TYPE] & 0x80) != 0)
159 static int dev_pci_slot(struct udev_device *dev, struct netnames *names) {
160 struct udev *udev = udev_device_get_udev(names->pcidev);
164 unsigned int dev_id = 0;
168 struct udev_device *pci = NULL;
173 int hotplug_slot = 0;
176 if (sscanf(udev_device_get_sysname(names->pcidev), "0000:%x:%x.%d", &bus, &slot, &func) != 3)
179 /* kernel provided multi-device index */
180 attr = udev_device_get_sysattr_value(dev, "dev_id");
182 dev_id = strtol(attr, NULL, 16);
184 /* compose a name based on the raw kernel's PCI bus, slot numbers */
186 l = strpcpyf(&s, sizeof(names->pci_path), "p%ds%d", bus, slot);
187 if (func > 0 || is_pci_multifunction(names->pcidev))
188 l = strpcpyf(&s, l, "f%d", func);
190 l = strpcpyf(&s, l, "d%d", dev_id);
192 names->pci_path[0] = '\0';
194 /* ACPI _SUN -- slot user number */
195 pci = udev_device_new_from_subsystem_sysname(udev, "subsystem", "pci");
200 snprintf(slots, sizeof(slots), "%s/slots", udev_device_get_syspath(pci));
201 dir = opendir(slots);
207 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
212 if (dent->d_name[0] == '.')
214 i = strtol(dent->d_name, &rest, 10);
219 snprintf(str, sizeof(str), "%s/%s/address", slots, dent->d_name);
220 if (read_one_line_file(str, &address) >= 0) {
221 /* match slot address with device by stripping the function */
222 if (strncmp(address, udev_device_get_sysname(names->pcidev), strlen(address)) == 0)
227 if (hotplug_slot > 0)
232 if (hotplug_slot > 0) {
234 l = strpcpyf(&s, sizeof(names->pci_slot), "s%d", hotplug_slot);
235 if (func > 0 || is_pci_multifunction(names->pcidev))
236 l = strpcpyf(&s, l, "f%d", func);
238 l = strpcpyf(&s, l, "d%d", dev_id);
240 names->pci_path[0] = '\0';
243 udev_device_unref(pci);
247 static int names_pci(struct udev_device *dev, struct netnames *names) {
248 struct udev_device *parent;
250 parent = udev_device_get_parent(dev);
253 /* check if our direct parent is a PCI device with no other bus in-between */
254 if (streq("pci", udev_device_get_subsystem(parent))) {
255 names->type = NET_PCI;
256 names->pcidev = parent;
258 names->pcidev = udev_device_get_parent_with_subsystem_devtype(dev, "pci", NULL);
262 dev_pci_onboard(dev, names);
263 dev_pci_slot(dev, names);
267 static int names_usb(struct udev_device *dev, struct netnames *names) {
275 names->usbdev = udev_device_get_parent_with_subsystem_devtype(dev, "usb", "usb_interface");
279 /* get USB port number chain, configuration, interface */
280 strscpy(name, sizeof(name), udev_device_get_sysname(names->usbdev));
281 s = strchr(name, '-');
286 s = strchr(ports, ':');
292 s = strchr(config, '.');
298 /* prefix every port number in the chain with "u"*/
300 while ((s = strchr(s, '.')))
302 s = names->usb_ports;
303 l = strpcpyl(&s, sizeof(names->usb_ports), "u", ports, NULL);
305 /* append USB config number, suppress the common config == 1 */
306 if (!streq(config, "1"))
307 l = strpcpyl(&s, sizeof(names->usb_ports), "c", config, NULL);
309 /* append USB interface number, suppress the interface == 0 */
310 if (!streq(interf, "0"))
311 l = strpcpyl(&s, sizeof(names->usb_ports), "i", interf, NULL);
313 return -ENAMETOOLONG;
315 names->type = NET_USB;
319 static int names_mac(struct udev_device *dev, struct netnames *names) {
322 unsigned int a1, a2, a3, a4, a5, a6;
324 /* check for NET_ADDR_PERM, skip random MAC addresses */
325 s = udev_device_get_sysattr_value(dev, "addr_assign_type");
328 i = strtoul(s, NULL, 0);
332 s = udev_device_get_sysattr_value(dev, "address");
335 if (sscanf(s, "%x:%x:%x:%x:%x:%x", &a1, &a2, &a3, &a4, &a5, &a6) != 6)
338 /* skip empty MAC addresses */
339 if (a1 + a2 + a3 + a4 + a5 + a6 == 0)
348 names->mac_valid = true;
352 /* IEEE Organizationally Unique Identifier vendor string */
353 static int ieee_oui(struct udev_device *dev, struct netnames *names, bool test) {
356 if (!names->mac_valid)
358 /* skip commonly misused 00:00:00 (Xerox) prefix */
359 if (memcmp(names->mac, "\0\0\0", 3) == 0)
361 snprintf(str, sizeof(str), "OUI:%02X%02X%02X%02X%02X%02X",
362 names->mac[0], names->mac[1], names->mac[2],
363 names->mac[3], names->mac[4], names->mac[5]);
364 udev_builtin_hwdb_lookup(dev, str, test);
368 static int builtin_net_id(struct udev_device *dev, int argc, char *argv[], bool test) {
373 const char *prefix = "en";
374 struct netnames names;
377 /* handle only ARPHRD_ETHER devices */
378 s = udev_device_get_sysattr_value(dev, "type");
381 i = strtoul(s, NULL, 0);
385 /* skip stacked devices, like VLANs, ... */
386 s = udev_device_get_sysattr_value(dev, "ifindex");
389 p = udev_device_get_sysattr_value(dev, "iflink");
392 if (strcmp(s, p) != 0)
395 devtype = udev_device_get_devtype(dev);
397 if (streq("wlan", devtype))
399 else if (streq("wwan", devtype))
404 err = names_mac(dev, &names);
405 if (err >= 0 && names.mac_valid) {
408 snprintf(str, sizeof(str), "%sx%02x%02x%02x%02x%02x%02x", prefix,
409 names.mac[0], names.mac[1], names.mac[2],
410 names.mac[3], names.mac[4], names.mac[5]);
411 udev_builtin_add_property(dev, test, "ID_NET_NAME_MAC", str);
413 ieee_oui(dev, &names, test);
416 /* get PCI based path names, we compose only PCI based paths */
417 err = names_pci(dev, &names);
421 /* plain PCI device */
422 if (names.type == NET_PCI) {
425 if (names.pci_onboard[0])
426 if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_onboard) < (int)sizeof(str))
427 udev_builtin_add_property(dev, test, "ID_NET_NAME_ONBOARD", str);
429 if (names.pci_onboard_label)
430 if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_onboard_label) < (int)sizeof(str))
431 udev_builtin_add_property(dev, test, "ID_NET_LABEL_ONBOARD", str);
433 if (names.pci_path[0])
434 if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_path) < (int)sizeof(str))
435 udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
437 if (names.pci_slot[0])
438 if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_slot) < (int)sizeof(str))
439 udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
444 err = names_usb(dev, &names);
445 if (err >= 0 && names.type == NET_USB) {
448 if (names.pci_path[0])
449 if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_path, names.usb_ports) < (int)sizeof(str))
450 udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
452 if (names.pci_slot[0])
453 if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_slot, names.usb_ports) < (int)sizeof(str))
454 udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
460 const struct udev_builtin udev_builtin_net_id = {
462 .cmd = builtin_net_id,
463 .help = "network device properties",