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