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