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 * http://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames
29 * Two character prefixes based on the type of interface:
35 * o<index> -- on-board device index number
36 * s<slot>[f<function>][d<dev_id>] -- hotplug slot index number
37 * x<MAC> -- MAC address
38 * p<bus>s<slot>[f<function>][d<dev_id>] -- PCI geographical location
39 * p<bus>s<slot>[f<function>][u<port>][..][c<config>][i<interface>]
40 * -- USB port number chain
42 * All multi-function PCI devices will carry the [f<function>] number in the
43 * device name, including the function 0 device.
45 * For USB devices the full chain of port numbers of hubs is composed. If the
46 * name gets longer than the maximum number of 15 characters, the name is not
48 * The usual USB configuration == 1 and interface == 0 values are suppressed.
50 * PCI ethernet card with firmware index "1":
51 * ID_NET_NAME_ONBOARD=eno1
52 * ID_NET_NAME_ONBOARD_LABEL=Ethernet Port 1
54 * PCI ethernet card in hotplug slot with firmware index number:
55 * /sys/devices/pci0000:00/0000:00:1c.3/0000:05:00.0/net/ens1
56 * ID_NET_NAME_MAC=enx000000000466
57 * ID_NET_NAME_PATH=enp5s0
58 * ID_NET_NAME_SLOT=ens1
60 * PCI ethernet multi-function card with 2 ports:
61 * /sys/devices/pci0000:00/0000:00:1c.0/0000:02:00.0/net/enp2s0f0
62 * ID_NET_NAME_MAC=enx78e7d1ea46da
63 * ID_NET_NAME_PATH=enp2s0f0
64 * /sys/devices/pci0000:00/0000:00:1c.0/0000:02:00.1/net/enp2s0f1
65 * ID_NET_NAME_MAC=enx78e7d1ea46dc
66 * ID_NET_NAME_PATH=enp2s0f1
69 * /sys/devices/pci0000:00/0000:00:1c.1/0000:03:00.0/net/wlp3s0
70 * ID_NET_NAME_MAC=wlx0024d7e31130
71 * ID_NET_NAME_PATH=wlp3s0
73 * USB built-in 3G modem:
74 * /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4:1.6/net/wwp0s29u1u4i6
75 * ID_NET_NAME_MAC=wwx028037ec0200
76 * ID_NET_NAME_PATH=wwp0s29u1u4i6
79 * /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0/net/enp0s29u1u2
80 * ID_NET_NAME_MAC=enxd626b3450fb5
81 * ID_NET_NAME_PATH=enp0s29u1u2
91 #include <linux/pci_regs.h>
104 enum netname_type type;
109 struct udev_device *pcidev;
110 char pci_slot[IFNAMSIZ];
111 char pci_path[IFNAMSIZ];
112 char pci_onboard[IFNAMSIZ];
113 const char *pci_onboard_label;
115 char usb_ports[IFNAMSIZ];
117 char bcma_core[IFNAMSIZ];
120 /* retrieve on-board index number and label from firmware */
121 static int dev_pci_onboard(struct udev_device *dev, struct netnames *names) {
125 /* ACPI _DSM -- device specific method for naming a PCI or PCI Express device */
126 index = udev_device_get_sysattr_value(names->pcidev, "acpi_index");
127 /* SMBIOS type 41 -- Onboard Devices Extended Information */
129 index = udev_device_get_sysattr_value(names->pcidev, "index");
132 idx = strtoul(index, NULL, 0);
135 snprintf(names->pci_onboard, sizeof(names->pci_onboard), "o%d", idx);
137 names->pci_onboard_label = udev_device_get_sysattr_value(names->pcidev, "label");
141 /* read the 256 bytes PCI configuration space to check the multi-function bit */
142 static bool is_pci_multifunction(struct udev_device *dev) {
148 snprintf(filename, sizeof(filename), "%s/config", udev_device_get_syspath(dev));
149 f = fopen(filename, "re");
152 if (fread(&config, sizeof(config), 1, f) != 1)
155 /* bit 0-6 header type, bit 7 multi/single function device */
156 if ((config[PCI_HEADER_TYPE] & 0x80) != 0)
164 static int dev_pci_slot(struct udev_device *dev, struct netnames *names) {
165 struct udev *udev = udev_device_get_udev(names->pcidev);
169 unsigned int dev_id = 0;
173 struct udev_device *pci = NULL;
178 int hotplug_slot = 0;
181 if (sscanf(udev_device_get_sysname(names->pcidev), "0000:%x:%x.%d", &bus, &slot, &func) != 3)
184 /* kernel provided multi-device index */
185 attr = udev_device_get_sysattr_value(dev, "dev_id");
187 dev_id = strtol(attr, NULL, 16);
189 /* compose a name based on the raw kernel's PCI bus, slot numbers */
191 l = strpcpyf(&s, sizeof(names->pci_path), "p%ds%d", bus, slot);
192 if (func > 0 || is_pci_multifunction(names->pcidev))
193 l = strpcpyf(&s, l, "f%d", func);
195 l = strpcpyf(&s, l, "d%d", dev_id);
197 names->pci_path[0] = '\0';
199 /* ACPI _SUN -- slot user number */
200 pci = udev_device_new_from_subsystem_sysname(udev, "subsystem", "pci");
205 snprintf(slots, sizeof(slots), "%s/slots", udev_device_get_syspath(pci));
206 dir = opendir(slots);
212 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
217 if (dent->d_name[0] == '.')
219 i = strtol(dent->d_name, &rest, 10);
224 snprintf(str, sizeof(str), "%s/%s/address", slots, dent->d_name);
225 if (read_one_line_file(str, &address) >= 0) {
226 /* match slot address with device by stripping the function */
227 if (strneq(address, udev_device_get_sysname(names->pcidev), strlen(address)))
232 if (hotplug_slot > 0)
237 if (hotplug_slot > 0) {
239 l = strpcpyf(&s, sizeof(names->pci_slot), "s%d", hotplug_slot);
240 if (func > 0 || is_pci_multifunction(names->pcidev))
241 l = strpcpyf(&s, l, "f%d", func);
243 l = strpcpyf(&s, l, "d%d", dev_id);
245 names->pci_path[0] = '\0';
248 udev_device_unref(pci);
252 static int names_pci(struct udev_device *dev, struct netnames *names) {
253 struct udev_device *parent;
255 parent = udev_device_get_parent(dev);
258 /* check if our direct parent is a PCI device with no other bus in-between */
259 if (streq_ptr("pci", udev_device_get_subsystem(parent))) {
260 names->type = NET_PCI;
261 names->pcidev = parent;
263 names->pcidev = udev_device_get_parent_with_subsystem_devtype(dev, "pci", NULL);
267 dev_pci_onboard(dev, names);
268 dev_pci_slot(dev, names);
272 static int names_usb(struct udev_device *dev, struct netnames *names) {
273 struct udev_device *usbdev;
281 usbdev = udev_device_get_parent_with_subsystem_devtype(dev, "usb", "usb_interface");
285 /* get USB port number chain, configuration, interface */
286 strscpy(name, sizeof(name), udev_device_get_sysname(usbdev));
287 s = strchr(name, '-');
292 s = strchr(ports, ':');
298 s = strchr(config, '.');
304 /* prefix every port number in the chain with "u"*/
306 while ((s = strchr(s, '.')))
308 s = names->usb_ports;
309 l = strpcpyl(&s, sizeof(names->usb_ports), "u", ports, NULL);
311 /* append USB config number, suppress the common config == 1 */
312 if (!streq(config, "1"))
313 l = strpcpyl(&s, sizeof(names->usb_ports), "c", config, NULL);
315 /* append USB interface number, suppress the interface == 0 */
316 if (!streq(interf, "0"))
317 l = strpcpyl(&s, sizeof(names->usb_ports), "i", interf, NULL);
319 return -ENAMETOOLONG;
321 names->type = NET_USB;
325 static int names_bcma(struct udev_device *dev, struct netnames *names) {
326 struct udev_device *bcmadev;
329 bcmadev = udev_device_get_parent_with_subsystem_devtype(dev, "bcma", NULL);
333 /* bus num:core num */
334 if (sscanf(udev_device_get_sysname(bcmadev), "bcma%*d:%d", &core) != 1)
336 /* suppress the common core == 0 */
338 snprintf(names->bcma_core, sizeof(names->bcma_core), "b%d", core);
340 names->type = NET_BCMA;
344 static int names_mac(struct udev_device *dev, struct netnames *names) {
347 unsigned int a1, a2, a3, a4, a5, a6;
349 /* check for NET_ADDR_PERM, skip random MAC addresses */
350 s = udev_device_get_sysattr_value(dev, "addr_assign_type");
353 i = strtoul(s, NULL, 0);
357 s = udev_device_get_sysattr_value(dev, "address");
360 if (sscanf(s, "%x:%x:%x:%x:%x:%x", &a1, &a2, &a3, &a4, &a5, &a6) != 6)
363 /* skip empty MAC addresses */
364 if (a1 + a2 + a3 + a4 + a5 + a6 == 0)
373 names->mac_valid = true;
377 /* IEEE Organizationally Unique Identifier vendor string */
378 static int ieee_oui(struct udev_device *dev, struct netnames *names, bool test) {
381 if (!names->mac_valid)
383 /* skip commonly misused 00:00:00 (Xerox) prefix */
384 if (memcmp(names->mac, "\0\0\0", 3) == 0)
386 snprintf(str, sizeof(str), "OUI:%02X%02X%02X%02X%02X%02X",
387 names->mac[0], names->mac[1], names->mac[2],
388 names->mac[3], names->mac[4], names->mac[5]);
389 udev_builtin_hwdb_lookup(dev, str, test);
393 static int builtin_net_id(struct udev_device *dev, int argc, char *argv[], bool test) {
398 const char *prefix = "en";
399 struct netnames names;
402 /* handle only ARPHRD_ETHER devices */
403 s = udev_device_get_sysattr_value(dev, "type");
406 i = strtoul(s, NULL, 0);
410 /* skip stacked devices, like VLANs, ... */
411 s = udev_device_get_sysattr_value(dev, "ifindex");
414 p = udev_device_get_sysattr_value(dev, "iflink");
420 devtype = udev_device_get_devtype(dev);
422 if (streq("wlan", devtype))
424 else if (streq("wwan", devtype))
429 err = names_mac(dev, &names);
430 if (err >= 0 && names.mac_valid) {
433 snprintf(str, sizeof(str), "%sx%02x%02x%02x%02x%02x%02x", prefix,
434 names.mac[0], names.mac[1], names.mac[2],
435 names.mac[3], names.mac[4], names.mac[5]);
436 udev_builtin_add_property(dev, test, "ID_NET_NAME_MAC", str);
438 ieee_oui(dev, &names, test);
441 /* get PCI based path names, we compose only PCI based paths */
442 err = names_pci(dev, &names);
446 /* plain PCI device */
447 if (names.type == NET_PCI) {
450 if (names.pci_onboard[0])
451 if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_onboard) < (int)sizeof(str))
452 udev_builtin_add_property(dev, test, "ID_NET_NAME_ONBOARD", str);
454 if (names.pci_onboard_label)
455 if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_onboard_label) < (int)sizeof(str))
456 udev_builtin_add_property(dev, test, "ID_NET_LABEL_ONBOARD", str);
458 if (names.pci_path[0])
459 if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_path) < (int)sizeof(str))
460 udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
462 if (names.pci_slot[0])
463 if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_slot) < (int)sizeof(str))
464 udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
469 err = names_usb(dev, &names);
470 if (err >= 0 && names.type == NET_USB) {
473 if (names.pci_path[0])
474 if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_path, names.usb_ports) < (int)sizeof(str))
475 udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
477 if (names.pci_slot[0])
478 if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_slot, names.usb_ports) < (int)sizeof(str))
479 udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
484 err = names_bcma(dev, &names);
485 if (err >= 0 && names.type == NET_BCMA) {
488 if (names.pci_path[0])
489 if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_path, names.bcma_core) < (int)sizeof(str))
490 udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
492 if (names.pci_slot[0])
493 if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_slot, names.bcma_core) < (int)sizeof(str))
494 udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
502 const struct udev_builtin udev_builtin_net_id = {
504 .cmd = builtin_net_id,
505 .help = "network device properties",