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