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  *   wl -- wlan
  32  *   ww -- wwan
  33  *
  34  * Type of names:
  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
  41  *
  42  * All multi-function PCI devices will carry the [f<function>] number in the
  43  * device name, including the function 0 device.
  44  *
  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
  47  * exported.
  48  * The usual USB configuration == 1 and interface == 0 values are suppressed.
  49  *
  50  * PCI ethernet card with firmware index "1":
  51  *   ID_NET_NAME_ONBOARD=eno1
  52  *   ID_NET_NAME_ONBOARD_LABEL=Ethernet Port 1
  53  *
  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
  59  *
  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
  67  *
  68  * PCI wlan card:
  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
  72  *
  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
  77  *
  78  * USB Android phone:
  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
  82  */
  83
  84 #include <stdio.h>
  85 #include <stdlib.h>
  86 #include <stdarg.h>
  87 #include <unistd.h>
  88 #include <string.h>
  89 #include <errno.h>
  90 #include <net/if.h>
  91 #include <linux/pci_regs.h>
  92
  93 #include "udev.h"
  94 #include "fileio.h"
  95
  96 enum netname_type{
  97         NET_UNDEF,
  98         NET_PCI,
  99         NET_USB,
 100         NET_BCMA,
 101 };
 102
 103 struct netnames {
 104         enum netname_type type;
 105
 106         uint8_t mac[6];
 107         bool mac_valid;
 108
 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;
 114
 115         char usb_ports[IFNAMSIZ];
 116
 117         char bcma_core[IFNAMSIZ];
 118 };
 119
 120 /* retrieve on-board index number and label from firmware */
 121 static int dev_pci_onboard(struct udev_device *dev, struct netnames *names) {
 122         const char *index;
 123         int idx;
 124
 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 */
 128         if (!index)
 129                 index = udev_device_get_sysattr_value(names->pcidev, "index");
 130         if (!index)
 131                 return -ENOENT;
 132         idx = strtoul(index, NULL, 0);
 133         if (idx <= 0)
 134                 return -EINVAL;
 135         snprintf(names->pci_onboard, sizeof(names->pci_onboard), "o%d", idx);
 136
 137         names->pci_onboard_label = udev_device_get_sysattr_value(names->pcidev, "label");
 138         return 0;
 139 }
 140
 141 /* read the 256 bytes PCI configuration space to check the multi-function bit */
 142 static bool is_pci_multifunction(struct udev_device *dev) {
 143         char filename[256];
 144         FILE *f = NULL;
 145         char config[64];
 146         bool multi = false;
 147
 148         snprintf(filename, sizeof(filename), "%s/config", udev_device_get_syspath(dev));
 149         f = fopen(filename, "re");
 150         if (!f)
 151                 goto out;
 152         if (fread(&config, sizeof(config), 1, f) != 1)
 153                 goto out;
 154
 155         /* bit 0-6 header type, bit 7 multi/single function device */
 156         if ((config[PCI_HEADER_TYPE] & 0x80) != 0)
 157                 multi = true;
 158 out:
 159         if(f)
 160                 fclose(f);
 161         return multi;
 162 }
 163
 164 static int dev_pci_slot(struct udev_device *dev, struct netnames *names) {
 165         struct udev *udev = udev_device_get_udev(names->pcidev);
 166         unsigned int bus;
 167         unsigned int slot;
 168         unsigned int func;
 169         unsigned int dev_id = 0;
 170         size_t l;
 171         char *s;
 172         const char *attr;
 173         struct udev_device *pci = NULL;
 174         char slots[256];
 175         DIR *dir;
 176         struct dirent *dent;
 177         char str[256];
 178         int hotplug_slot = 0;
 179         int err = 0;
 180
 181         if (sscanf(udev_device_get_sysname(names->pcidev), "0000:%x:%x.%d", &bus, &slot, &func) != 3)
 182                 return -ENOENT;
 183
 184         /* kernel provided multi-device index */
 185         attr = udev_device_get_sysattr_value(dev, "dev_id");
 186         if (attr)
 187                 dev_id = strtol(attr, NULL, 16);
 188
 189         /* compose a name based on the raw kernel's PCI bus, slot numbers */
 190         s = names->pci_path;
 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);
 194         if (dev_id > 0)
 195                 l = strpcpyf(&s, l, "d%d", dev_id);
 196         if (l == 0)
 197                 names->pci_path[0] = '\0';
 198
 199         /* ACPI _SUN  -- slot user number */
 200         pci = udev_device_new_from_subsystem_sysname(udev, "subsystem", "pci");
 201         if (!pci) {
 202                 err = -ENOENT;
 203                 goto out;
 204         }
 205         snprintf(slots, sizeof(slots), "%s/slots", udev_device_get_syspath(pci));
 206         dir = opendir(slots);
 207         if (!dir) {
 208                 err = -errno;
 209                 goto out;
 210         }
 211
 212         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 213                 int i;
 214                 char *rest;
 215                 char *address;
 216
 217                 if (dent->d_name[0] == '.')
 218                         continue;
 219                 i = strtol(dent->d_name, &rest, 10);
 220                 if (rest[0] != '\0')
 221                         continue;
 222                 if (i < 1)
 223                         continue;
 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)))
 228                                 hotplug_slot = i;
 229                         free(address);
 230                 }
 231
 232                 if (hotplug_slot > 0)
 233                         break;
 234         }
 235         closedir(dir);
 236
 237         if (hotplug_slot > 0) {
 238                 s = names->pci_slot;
 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);
 242                 if (dev_id > 0)
 243                         l = strpcpyf(&s, l, "d%d", dev_id);
 244                 if (l == 0)
 245                         names->pci_path[0] = '\0';
 246         }
 247 out:
 248         udev_device_unref(pci);
 249         return err;
 250 }
 251
 252 static int names_pci(struct udev_device *dev, struct netnames *names) {
 253         struct udev_device *parent;
 254
 255         parent = udev_device_get_parent(dev);
 256         if (!parent)
 257                 return -ENOENT;
 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;
 262         } else {
 263                 names->pcidev = udev_device_get_parent_with_subsystem_devtype(dev, "pci", NULL);
 264                 if (!names->pcidev)
 265                         return -ENOENT;
 266         }
 267         dev_pci_onboard(dev, names);
 268         dev_pci_slot(dev, names);
 269         return 0;
 270 }
 271
 272 static int names_usb(struct udev_device *dev, struct netnames *names) {
 273         struct udev_device *usbdev;
 274         char name[256];
 275         char *ports;
 276         char *config;
 277         char *interf;
 278         size_t l;
 279         char *s;
 280
 281         usbdev = udev_device_get_parent_with_subsystem_devtype(dev, "usb", "usb_interface");
 282         if (!usbdev)
 283                 return -ENOENT;
 284
 285         /* get USB port number chain, configuration, interface */
 286         strscpy(name, sizeof(name), udev_device_get_sysname(usbdev));
 287         s = strchr(name, '-');
 288         if (!s)
 289                 return -EINVAL;
 290         ports = s+1;
 291
 292         s = strchr(ports, ':');
 293         if (!s)
 294                 return -EINVAL;
 295         s[0] = '\0';
 296         config = s+1;
 297
 298         s = strchr(config, '.');
 299         if (!s)
 300                 return -EINVAL;
 301         s[0] = '\0';
 302         interf = s+1;
 303
 304         /* prefix every port number in the chain with "u"*/
 305         s = ports;
 306         while ((s = strchr(s, '.')))
 307                 s[0] = 'u';
 308         s = names->usb_ports;
 309         l = strpcpyl(&s, sizeof(names->usb_ports), "u", ports, NULL);
 310
 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);
 314
 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);
 318         if (l == 0)
 319                 return -ENAMETOOLONG;
 320
 321         names->type = NET_USB;
 322         return 0;
 323 }
 324
 325 static int names_bcma(struct udev_device *dev, struct netnames *names) {
 326         struct udev_device *bcmadev;
 327         unsigned int core;
 328
 329         bcmadev = udev_device_get_parent_with_subsystem_devtype(dev, "bcma", NULL);
 330         if (!bcmadev)
 331                 return -ENOENT;
 332
 333         /* bus num:core num */
 334         if (sscanf(udev_device_get_sysname(bcmadev), "bcma%*d:%d", &core) != 1)
 335                 return -EINVAL;
 336         /* suppress the common core == 0 */
 337         if (core > 0)
 338                 snprintf(names->bcma_core, sizeof(names->bcma_core), "b%d", core);
 339
 340         names->type = NET_BCMA;
 341         return 0;
 342 }
 343
 344 static int names_mac(struct udev_device *dev, struct netnames *names) {
 345         const char *s;
 346         unsigned int i;
 347         unsigned int a1, a2, a3, a4, a5, a6;
 348
 349         /* check for NET_ADDR_PERM, skip random MAC addresses */
 350         s = udev_device_get_sysattr_value(dev, "addr_assign_type");
 351         if (!s)
 352                 return EXIT_FAILURE;
 353         i = strtoul(s, NULL, 0);
 354         if (i != 0)
 355                 return 0;
 356
 357         s = udev_device_get_sysattr_value(dev, "address");
 358         if (!s)
 359                 return -ENOENT;
 360         if (sscanf(s, "%x:%x:%x:%x:%x:%x", &a1, &a2, &a3, &a4, &a5, &a6) != 6)
 361                 return -EINVAL;
 362
 363         /* skip empty MAC addresses */
 364         if (a1 + a2 + a3 + a4 + a5 + a6 == 0)
 365                 return -EINVAL;
 366
 367         names->mac[0] = a1;
 368         names->mac[1] = a2;
 369         names->mac[2] = a3;
 370         names->mac[3] = a4;
 371         names->mac[4] = a5;
 372         names->mac[5] = a6;
 373         names->mac_valid = true;
 374         return 0;
 375 }
 376
 377 /* IEEE Organizationally Unique Identifier vendor string */
 378 static int ieee_oui(struct udev_device *dev, struct netnames *names, bool test) {
 379         char str[32];
 380
 381         if (!names->mac_valid)
 382                 return -ENOENT;
 383         /* skip commonly misused 00:00:00 (Xerox) prefix */
 384         if (memcmp(names->mac, "\0\0\0", 3) == 0)
 385                 return -EINVAL;
 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);
 390         return 0;
 391 }
 392
 393 static int builtin_net_id(struct udev_device *dev, int argc, char *argv[], bool test) {
 394         const char *s;
 395         const char *p;
 396         unsigned int i;
 397         const char *devtype;
 398         const char *prefix = "en";
 399         struct netnames names = {};
 400         int err;
 401
 402         /* handle only ARPHRD_ETHER devices */
 403         s = udev_device_get_sysattr_value(dev, "type");
 404         if (!s)
 405                 return EXIT_FAILURE;
 406         i = strtoul(s, NULL, 0);
 407         if (i != 1)
 408                 return 0;
 409
 410         /* skip stacked devices, like VLANs, ... */
 411         s = udev_device_get_sysattr_value(dev, "ifindex");
 412         if (!s)
 413                 return EXIT_FAILURE;
 414         p = udev_device_get_sysattr_value(dev, "iflink");
 415         if (!p)
 416                 return EXIT_FAILURE;
 417         if (!streq(s, p))
 418                 return 0;
 419
 420         devtype = udev_device_get_devtype(dev);
 421         if (devtype) {
 422                 if (streq("wlan", devtype))
 423                         prefix = "wl";
 424                 else if (streq("wwan", devtype))
 425                         prefix = "ww";
 426         }
 427
 428         err = names_mac(dev, &names);
 429         if (err >= 0 && names.mac_valid) {
 430                 char str[IFNAMSIZ];
 431
 432                 snprintf(str, sizeof(str), "%sx%02x%02x%02x%02x%02x%02x", prefix,
 433                          names.mac[0], names.mac[1], names.mac[2],
 434                          names.mac[3], names.mac[4], names.mac[5]);
 435                 udev_builtin_add_property(dev, test, "ID_NET_NAME_MAC", str);
 436
 437                 ieee_oui(dev, &names, test);
 438         }
 439
 440         /* get PCI based path names, we compose only PCI based paths */
 441         err = names_pci(dev, &names);
 442         if (err < 0)
 443                 goto out;
 444
 445         /* plain PCI device */
 446         if (names.type == NET_PCI) {
 447                 char str[IFNAMSIZ];
 448
 449                 if (names.pci_onboard[0])
 450                         if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_onboard) < (int)sizeof(str))
 451                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_ONBOARD", str);
 452
 453                 if (names.pci_onboard_label)
 454                         if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_onboard_label) < (int)sizeof(str))
 455                                 udev_builtin_add_property(dev, test, "ID_NET_LABEL_ONBOARD", str);
 456
 457                 if (names.pci_path[0])
 458                         if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_path) < (int)sizeof(str))
 459                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
 460
 461                 if (names.pci_slot[0])
 462                         if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_slot) < (int)sizeof(str))
 463                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
 464                 goto out;
 465         }
 466
 467         /* USB device */
 468         err = names_usb(dev, &names);
 469         if (err >= 0 && names.type == NET_USB) {
 470                 char str[IFNAMSIZ];
 471
 472                 if (names.pci_path[0])
 473                         if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_path, names.usb_ports) < (int)sizeof(str))
 474                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
 475
 476                 if (names.pci_slot[0])
 477                         if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_slot, names.usb_ports) < (int)sizeof(str))
 478                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
 479                 goto out;
 480         }
 481
 482         /* Broadcom bus */
 483         err = names_bcma(dev, &names);
 484         if (err >= 0 && names.type == NET_BCMA) {
 485                 char str[IFNAMSIZ];
 486
 487                 if (names.pci_path[0])
 488                         if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_path, names.bcma_core) < (int)sizeof(str))
 489                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
 490
 491                 if (names.pci_slot[0])
 492                         if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_slot, names.bcma_core) < (int)sizeof(str))
 493                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
 494                 goto out;
 495         }
 496
 497 out:
 498         return EXIT_SUCCESS;
 499 }
 500
 501 const struct udev_builtin udev_builtin_net_id = {
 502         .name = "net_id",
 503         .cmd = builtin_net_id,
 504         .help = "network device properties",
 505 };