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>] -- hotplug slot index number
35 * x<MAC> -- MAC address
36 * p<bus>s<slot>[f<function>] -- 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
49 * ID_NET_NAME_ONBOARD=eno1
50 * ID_NET_NAME_ONBOARD_LABEL=Ethernet Port 1
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 card in hotplug slot with firmware index number:
59 * /sys/devices/pci0000:00/0000:00:1c.3/0000:05:00.0/net/ens1
60 * ID_NET_NAME_MAC=enx000000000466
61 * ID_NET_NAME_PATH=enp5s0
62 * ID_NET_NAME_SLOT=ens1
65 * /sys/devices/pci0000:00/0000:00:1c.1/0000:03:00.0/net/wlp3s0
66 * ID_NET_NAME_MAC=wlx0024d7e31130
67 * ID_NET_NAME_PATH=wlp3s0
69 * USB built-in 3G modem:
70 * /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4:1.6/net/wwp0s29u1u4i6
71 * ID_NET_NAME_MAC=wwx028037ec0200
72 * ID_NET_NAME_PATH=wwp0s29u1u4i6
75 * /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0/net/enp0s29u1u2
76 * ID_NET_NAME_MAC=enxd626b3450fb5
77 * ID_NET_NAME_PATH=enp0s29u1u2
87 #include <linux/pci_regs.h>
98 enum netname_type type;
103 struct udev_device *pcidev;
104 char pci_slot[IFNAMSIZ];
105 char pci_path[IFNAMSIZ];
106 char pci_onboard[IFNAMSIZ];
107 const char *pci_onboard_label;
109 struct udev_device *usbdev;
110 char usb_ports[IFNAMSIZ];
113 /* retrieve on-board index number and label from firmware */
114 static int dev_pci_onboard(struct udev_device *dev, struct netnames *names) {
118 /* ACPI _DSM -- device specific method for naming a PCI or PCI Express device */
119 index = udev_device_get_sysattr_value(names->pcidev, "acpi_index");
120 /* SMBIOS type 41 -- Onboard Devices Extended Information */
122 index = udev_device_get_sysattr_value(names->pcidev, "index");
125 idx = strtoul(index, NULL, 0);
128 snprintf(names->pci_onboard, sizeof(names->pci_onboard), "o%d", idx);
130 names->pci_onboard_label = udev_device_get_sysattr_value(names->pcidev, "label");
134 /* read the 256 bytes PCI configuration space to check the multi-function bit */
135 static bool is_pci_singlefunction(struct udev_device *dev) {
141 snprintf(filename, sizeof(filename), "%s/config", udev_device_get_syspath(dev));
142 f = fopen(filename, "re");
145 if (fread(&config, sizeof(config), 1, f) != 1)
148 /* bit 0-6 header type, bit 7 multi/single function device */
149 if ((config[PCI_HEADER_TYPE] & 0x80) == 0)
156 static int dev_pci_slot(struct udev_device *dev, struct netnames *names) {
157 struct udev *udev = udev_device_get_udev(names->pcidev);
161 struct udev_device *pci = NULL;
166 int hotplug_slot = 0;
169 /* compose a name based on the raw kernel's PCI bus, slot numbers */
170 if (sscanf(udev_device_get_sysname(names->pcidev), "0000:%x:%x.%d", &bus, &slot, &func) != 3)
172 if (func == 0 && is_pci_singlefunction(names->pcidev))
173 snprintf(names->pci_path, sizeof(names->pci_path), "p%ds%d", bus, slot);
175 snprintf(names->pci_path, sizeof(names->pci_path), "p%ds%df%d", bus, slot, func);
177 /* ACPI _SUN -- slot user number */
178 pci = udev_device_new_from_subsystem_sysname(udev, "subsystem", "pci");
183 snprintf(slots, sizeof(slots), "%s/slots", udev_device_get_syspath(pci));
184 dir = opendir(slots);
190 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
195 if (dent->d_name[0] == '.')
197 i = strtol(dent->d_name, &rest, 10);
202 snprintf(str, sizeof(str), "%s/%s/address", slots, dent->d_name);
203 if (read_one_line_file(str, &address) >= 0) {
204 /* match slot address with device by stripping the function */
205 if (strncmp(address, udev_device_get_sysname(names->pcidev), strlen(address)) == 0)
210 if (hotplug_slot > 0)
215 if (hotplug_slot > 0) {
216 if (func == 0 && is_pci_singlefunction(names->pcidev))
217 snprintf(names->pci_slot, sizeof(names->pci_slot), "s%d", hotplug_slot);
219 snprintf(names->pci_slot, sizeof(names->pci_slot), "s%df%d", hotplug_slot, func);
222 udev_device_unref(pci);
226 static int names_pci(struct udev_device *dev, struct netnames *names) {
227 struct udev_device *parent;
229 parent = udev_device_get_parent(dev);
232 /* check if our direct parent is a PCI device with no other bus in-between */
233 if (streq("pci", udev_device_get_subsystem(parent))) {
234 names->type = NET_PCI;
235 names->pcidev = parent;
237 names->pcidev = udev_device_get_parent_with_subsystem_devtype(dev, "pci", NULL);
241 dev_pci_onboard(dev, names);
242 dev_pci_slot(dev, names);
246 static int names_usb(struct udev_device *dev, struct netnames *names) {
254 names->usbdev = udev_device_get_parent_with_subsystem_devtype(dev, "usb", "usb_interface");
258 /* get USB port number chain, configuration, interface */
259 util_strscpy(name, sizeof(name), udev_device_get_sysname(names->usbdev));
260 s = strchr(name, '-');
265 s = strchr(ports, ':');
271 s = strchr(config, '.');
277 /* prefix every port number in the chain with "u"*/
279 while ((s = strchr(s, '.')))
281 s = names->usb_ports;
282 l = util_strpcpyl(&s, sizeof(names->usb_ports), "u", ports, NULL);
284 /* append USB config number, suppress the common config == 1 */
285 if (!streq(config, "1"))
286 l = util_strpcpyl(&s, sizeof(names->usb_ports), "c", config, NULL);
288 /* append USB interface number, suppress the interface == 0 */
289 if (!streq(interf, "0"))
290 l = util_strpcpyl(&s, sizeof(names->usb_ports), "i", interf, NULL);
292 return -ENAMETOOLONG;
294 names->type = NET_USB;
298 static int names_mac(struct udev_device *dev, struct netnames *names) {
301 unsigned int a1, a2, a3, a4, a5, a6;
303 /* check for NET_ADDR_PERM, skip random MAC addresses */
304 s = udev_device_get_sysattr_value(dev, "addr_assign_type");
307 i = strtoul(s, NULL, 0);
311 s = udev_device_get_sysattr_value(dev, "address");
314 if (sscanf(s, "%x:%x:%x:%x:%x:%x", &a1, &a2, &a3, &a4, &a5, &a6) != 6)
317 /* skip empty MAC addresses */
318 if (a1 + a2 + a3 + a4 + a5 + a6 == 0)
327 names->mac_valid = true;
331 /* IEEE Organizationally Unique Identifier vendor string */
332 static int ieee_oui(struct udev_device *dev, struct netnames *names, bool test) {
335 if (!names->mac_valid)
337 /* skip commonly misused 00:00:00 (Xerox) prefix */
338 if (memcmp(names->mac, "\0\0\0", 3) == 0)
340 snprintf(str, sizeof(str), "OUI:%02X%02X%02X%02X%02X%02X",
341 names->mac[0], names->mac[1], names->mac[2],
342 names->mac[3], names->mac[4], names->mac[5]);
343 udev_builtin_hwdb_lookup(dev, str, test);
347 static int builtin_net_id(struct udev_device *dev, int argc, char *argv[], bool test) {
351 const char *prefix = "en";
352 struct netnames names;
355 /* handle only ARPHRD_ETHER devices */
356 s = udev_device_get_sysattr_value(dev, "type");
359 i = strtoul(s, NULL, 0);
363 devtype = udev_device_get_devtype(dev);
365 if (streq("wlan", devtype))
367 else if (streq("wwan", devtype))
372 err = names_mac(dev, &names);
373 if (err >= 0 && names.mac_valid) {
376 snprintf(str, sizeof(str), "%sx%02x%02x%02x%02x%02x%02x", prefix,
377 names.mac[0], names.mac[1], names.mac[2],
378 names.mac[3], names.mac[4], names.mac[5]);
379 udev_builtin_add_property(dev, test, "ID_NET_NAME_MAC", str);
381 ieee_oui(dev, &names, test);
384 /* get PCI based path names, we compose only PCI based paths */
385 err = names_pci(dev, &names);
389 /* plain PCI device */
390 if (names.type == NET_PCI) {
393 if (names.pci_onboard[0])
394 if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_onboard) < (int)sizeof(str))
395 udev_builtin_add_property(dev, test, "ID_NET_NAME_ONBOARD", str);
397 if (names.pci_onboard_label)
398 if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_onboard_label) < (int)sizeof(str))
399 udev_builtin_add_property(dev, test, "ID_NET_LABEL_ONBOARD", str);
401 if (names.pci_path[0])
402 if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_path) < (int)sizeof(str))
403 udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
405 if (names.pci_slot[0])
406 if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_slot) < (int)sizeof(str))
407 udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
412 err = names_usb(dev, &names);
413 if (err >= 0 && names.type == NET_USB) {
416 if (names.pci_path[0])
417 if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_path, names.usb_ports) < (int)sizeof(str))
418 udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
420 if (names.pci_slot[0])
421 if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_slot, names.usb_ports) < (int)sizeof(str))
422 udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
428 const struct udev_builtin udev_builtin_net_id = {
430 .cmd = builtin_net_id,
431 .help = "network device properties",