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