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  * Two character prefixes based on the type of interface:
  28  *   en -- ethernet
  29  *   wl -- wlan
  30  *   ww -- wwan
  31  *
  32  * Type of names:
  33  *   o<index>                              -- on-board device index number
  34  *   s<slot>[f<function>][d<dev_id>]       -- hotplug slot index number
  35  *   x<MAC>                                -- MAC address
  36  *   p<bus>s<slot>[f<function>][d<dev_id>] -- PCI geographical location
  37  *   p<bus>s<slot>[f<function>][u<port>][..][c<config>][i<interface>]
  38  *                                         -- USB port number chain
  39  *
  40  * All multi-function PCI devices will carry the [f<function>] number in the
  41  * device name, including the function 0 device.
  42  *
  43  * For USB devices the full chain of port numbers of hubs is composed. If the
  44  * name gets longer than the maximum number of 15 characters, the name is not
  45  * exported.
  46  * The usual USB configuration == 1 and interface == 0 values are suppressed.
  47  *
  48  * PCI ethernet card with firmware index "1":
  49  *   ID_NET_NAME_ONBOARD=eno1
  50  *   ID_NET_NAME_ONBOARD_LABEL=Ethernet Port 1
  51  *
  52  * PCI ethernet card in hotplug slot with firmware index number:
  53  *   /sys/devices/pci0000:00/0000:00:1c.3/0000:05:00.0/net/ens1
  54  *   ID_NET_NAME_MAC=enx000000000466
  55  *   ID_NET_NAME_PATH=enp5s0
  56  *   ID_NET_NAME_SLOT=ens1
  57  *
  58  * PCI ethernet multi-function card with 2 ports:
  59  *   /sys/devices/pci0000:00/0000:00:1c.0/0000:02:00.0/net/enp2s0f0
  60  *   ID_NET_NAME_MAC=enx78e7d1ea46da
  61  *   ID_NET_NAME_PATH=enp2s0f0
  62  *   /sys/devices/pci0000:00/0000:00:1c.0/0000:02:00.1/net/enp2s0f1
  63  *   ID_NET_NAME_MAC=enx78e7d1ea46dc
  64  *   ID_NET_NAME_PATH=enp2s0f1
  65  *
  66  * PCI wlan card:
  67  *   /sys/devices/pci0000:00/0000:00:1c.1/0000:03:00.0/net/wlp3s0
  68  *   ID_NET_NAME_MAC=wlx0024d7e31130
  69  *   ID_NET_NAME_PATH=wlp3s0
  70  *
  71  * USB built-in 3G modem:
  72  *   /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4/2-1.4:1.6/net/wwp0s29u1u4i6
  73  *   ID_NET_NAME_MAC=wwx028037ec0200
  74  *   ID_NET_NAME_PATH=wwp0s29u1u4i6
  75  *
  76  * USB Android phone:
  77  *   /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.2/2-1.2:1.0/net/enp0s29u1u2
  78  *   ID_NET_NAME_MAC=enxd626b3450fb5
  79  *   ID_NET_NAME_PATH=enp0s29u1u2
  80  */
  81
  82 #include <stdio.h>
  83 #include <stdlib.h>
  84 #include <stdarg.h>
  85 #include <unistd.h>
  86 #include <string.h>
  87 #include <errno.h>
  88 #include <net/if.h>
  89 #include <linux/pci_regs.h>
  90
  91 #include "udev.h"
  92
  93 enum netname_type{
  94         NET_UNDEF,
  95         NET_PCI,
  96         NET_USB,
  97         NET_BCMA,
  98 };
  99
 100 struct netnames {
 101         enum netname_type type;
 102
 103         uint8_t mac[6];
 104         bool mac_valid;
 105
 106         struct udev_device *pcidev;
 107         char pci_slot[IFNAMSIZ];
 108         char pci_path[IFNAMSIZ];
 109         char pci_onboard[IFNAMSIZ];
 110         const char *pci_onboard_label;
 111
 112         char usb_ports[IFNAMSIZ];
 113
 114         char bcma_core[IFNAMSIZ];
 115 };
 116
 117 /* retrieve on-board index number and label from firmware */
 118 static int dev_pci_onboard(struct udev_device *dev, struct netnames *names) {
 119         const char *index;
 120         int idx;
 121
 122         /* ACPI _DSM  -- device specific method for naming a PCI or PCI Express device */
 123         index = udev_device_get_sysattr_value(names->pcidev, "acpi_index");
 124         /* SMBIOS type 41 -- Onboard Devices Extended Information */
 125         if (!index)
 126                 index = udev_device_get_sysattr_value(names->pcidev, "index");
 127         if (!index)
 128                 return -ENOENT;
 129         idx = strtoul(index, NULL, 0);
 130         if (idx <= 0)
 131                 return -EINVAL;
 132         snprintf(names->pci_onboard, sizeof(names->pci_onboard), "o%d", idx);
 133
 134         names->pci_onboard_label = udev_device_get_sysattr_value(names->pcidev, "label");
 135         return 0;
 136 }
 137
 138 /* read the 256 bytes PCI configuration space to check the multi-function bit */
 139 static bool is_pci_multifunction(struct udev_device *dev) {
 140         char filename[256];
 141         FILE *f = NULL;
 142         char config[64];
 143         bool multi = false;
 144
 145         snprintf(filename, sizeof(filename), "%s/config", udev_device_get_syspath(dev));
 146         f = fopen(filename, "re");
 147         if (!f)
 148                 goto out;
 149         if (fread(&config, sizeof(config), 1, f) != 1)
 150                 goto out;
 151
 152         /* bit 0-6 header type, bit 7 multi/single function device */
 153         if ((config[PCI_HEADER_TYPE] & 0x80) != 0)
 154                 multi = true;
 155 out:
 156         if(f)
 157                 fclose(f);
 158         return multi;
 159 }
 160
 161 static int dev_pci_slot(struct udev_device *dev, struct netnames *names) {
 162         struct udev *udev = udev_device_get_udev(names->pcidev);
 163         unsigned int bus;
 164         unsigned int slot;
 165         unsigned int func;
 166         unsigned int dev_id = 0;
 167         size_t l;
 168         char *s;
 169         const char *attr;
 170         struct udev_device *pci = NULL;
 171         char slots[256];
 172         DIR *dir;
 173         struct dirent *dent;
 174         char str[256];
 175         int hotplug_slot = 0;
 176         int err = 0;
 177
 178         if (sscanf(udev_device_get_sysname(names->pcidev), "0000:%x:%x.%d", &bus, &slot, &func) != 3)
 179                 return -ENOENT;
 180
 181         /* kernel provided multi-device index */
 182         attr = udev_device_get_sysattr_value(dev, "dev_id");
 183         if (attr)
 184                 dev_id = strtol(attr, NULL, 16);
 185
 186         /* compose a name based on the raw kernel's PCI bus, slot numbers */
 187         s = names->pci_path;
 188         l = strpcpyf(&s, sizeof(names->pci_path), "p%ds%d", bus, slot);
 189         if (func > 0 || is_pci_multifunction(names->pcidev))
 190                 l = strpcpyf(&s, l, "f%d", func);
 191         if (dev_id > 0)
 192                 l = strpcpyf(&s, l, "d%d", dev_id);
 193         if (l == 0)
 194                 names->pci_path[0] = '\0';
 195
 196         /* ACPI _SUN  -- slot user number */
 197         pci = udev_device_new_from_subsystem_sysname(udev, "subsystem", "pci");
 198         if (!pci) {
 199                 err = -ENOENT;
 200                 goto out;
 201         }
 202         snprintf(slots, sizeof(slots), "%s/slots", udev_device_get_syspath(pci));
 203         dir = opendir(slots);
 204         if (!dir) {
 205                 err = -errno;
 206                 goto out;
 207         }
 208
 209         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 210                 int i;
 211                 char *rest;
 212                 char *address;
 213
 214                 if (dent->d_name[0] == '.')
 215                         continue;
 216                 i = strtol(dent->d_name, &rest, 10);
 217                 if (rest[0] != '\0')
 218                         continue;
 219                 if (i < 1)
 220                         continue;
 221                 snprintf(str, sizeof(str), "%s/%s/address", slots, dent->d_name);
 222                 if (read_one_line_file(str, &address) >= 0) {
 223                         /* match slot address with device by stripping the function */
 224                         if (strncmp(address, udev_device_get_sysname(names->pcidev), strlen(address)) == 0)
 225                                 hotplug_slot = i;
 226                         free(address);
 227                 }
 228
 229                 if (hotplug_slot > 0)
 230                         break;
 231         }
 232         closedir(dir);
 233
 234         if (hotplug_slot > 0) {
 235                 s = names->pci_slot;
 236                 l = strpcpyf(&s, sizeof(names->pci_slot), "s%d", hotplug_slot);
 237                 if (func > 0 || is_pci_multifunction(names->pcidev))
 238                         l = strpcpyf(&s, l, "f%d", func);
 239                 if (dev_id > 0)
 240                         l = strpcpyf(&s, l, "d%d", dev_id);
 241                 if (l == 0)
 242                         names->pci_path[0] = '\0';
 243         }
 244 out:
 245         udev_device_unref(pci);
 246         return err;
 247 }
 248
 249 static int names_pci(struct udev_device *dev, struct netnames *names) {
 250         struct udev_device *parent;
 251
 252         parent = udev_device_get_parent(dev);
 253         if (!parent)
 254                 return -ENOENT;
 255         /* check if our direct parent is a PCI device with no other bus in-between */
 256         if (streq("pci", udev_device_get_subsystem(parent))) {
 257                 names->type = NET_PCI;
 258                 names->pcidev = parent;
 259         } else {
 260                 names->pcidev = udev_device_get_parent_with_subsystem_devtype(dev, "pci", NULL);
 261                 if (!names->pcidev)
 262                         return -ENOENT;
 263         }
 264         dev_pci_onboard(dev, names);
 265         dev_pci_slot(dev, names);
 266         return 0;
 267 }
 268
 269 static int names_usb(struct udev_device *dev, struct netnames *names) {
 270         struct udev_device *usbdev;
 271         char name[256];
 272         char *ports;
 273         char *config;
 274         char *interf;
 275         size_t l;
 276         char *s;
 277
 278         usbdev = udev_device_get_parent_with_subsystem_devtype(dev, "usb", "usb_interface");
 279         if (!usbdev)
 280                 return -ENOENT;
 281
 282         /* get USB port number chain, configuration, interface */
 283         strscpy(name, sizeof(name), udev_device_get_sysname(usbdev));
 284         s = strchr(name, '-');
 285         if (!s)
 286                 return -EINVAL;
 287         ports = s+1;
 288
 289         s = strchr(ports, ':');
 290         if (!s)
 291                 return -EINVAL;
 292         s[0] = '\0';
 293         config = s+1;
 294
 295         s = strchr(config, '.');
 296         if (!s)
 297                 return -EINVAL;
 298         s[0] = '\0';
 299         interf = s+1;
 300
 301         /* prefix every port number in the chain with "u"*/
 302         s = ports;
 303         while ((s = strchr(s, '.')))
 304                 s[0] = 'u';
 305         s = names->usb_ports;
 306         l = strpcpyl(&s, sizeof(names->usb_ports), "u", ports, NULL);
 307
 308         /* append USB config number, suppress the common config == 1 */
 309         if (!streq(config, "1"))
 310                 l = strpcpyl(&s, sizeof(names->usb_ports), "c", config, NULL);
 311
 312         /* append USB interface number, suppress the interface == 0 */
 313         if (!streq(interf, "0"))
 314                 l = strpcpyl(&s, sizeof(names->usb_ports), "i", interf, NULL);
 315         if (l == 0)
 316                 return -ENAMETOOLONG;
 317
 318         names->type = NET_USB;
 319         return 0;
 320 }
 321
 322 static int names_bcma(struct udev_device *dev, struct netnames *names) {
 323         struct udev_device *bcmadev;
 324         unsigned int core;
 325
 326         bcmadev = udev_device_get_parent_with_subsystem_devtype(dev, "bcma", NULL);
 327         if (!bcmadev)
 328                 return -ENOENT;
 329
 330         /* bus num, core num */
 331         if (sscanf(udev_device_get_sysname(bcmadev), "bcma%*d:%d", &core) != 1)
 332                 return -EINVAL;
 333         snprintf(names->bcma_core, sizeof(names->bcma_core), "b%d", core);
 334         names->type = NET_BCMA;
 335         return 0;
 336 }
 337
 338 static int names_mac(struct udev_device *dev, struct netnames *names) {
 339         const char *s;
 340         unsigned int i;
 341         unsigned int a1, a2, a3, a4, a5, a6;
 342
 343         /* check for NET_ADDR_PERM, skip random MAC addresses */
 344         s = udev_device_get_sysattr_value(dev, "addr_assign_type");
 345         if (!s)
 346                 return EXIT_FAILURE;
 347         i = strtoul(s, NULL, 0);
 348         if (i != 0)
 349                 return 0;
 350
 351         s = udev_device_get_sysattr_value(dev, "address");
 352         if (!s)
 353                 return -ENOENT;
 354         if (sscanf(s, "%x:%x:%x:%x:%x:%x", &a1, &a2, &a3, &a4, &a5, &a6) != 6)
 355                 return -EINVAL;
 356
 357         /* skip empty MAC addresses */
 358         if (a1 + a2 + a3 + a4 + a5 + a6 == 0)
 359                 return -EINVAL;
 360
 361         names->mac[0] = a1;
 362         names->mac[1] = a2;
 363         names->mac[2] = a3;
 364         names->mac[3] = a4;
 365         names->mac[4] = a5;
 366         names->mac[5] = a6;
 367         names->mac_valid = true;
 368         return 0;
 369 }
 370
 371 /* IEEE Organizationally Unique Identifier vendor string */
 372 static int ieee_oui(struct udev_device *dev, struct netnames *names, bool test) {
 373         char str[32];
 374
 375         if (!names->mac_valid)
 376                 return -ENOENT;
 377         /* skip commonly misused 00:00:00 (Xerox) prefix */
 378         if (memcmp(names->mac, "\0\0\0", 3) == 0)
 379                 return -EINVAL;
 380         snprintf(str, sizeof(str), "OUI:%02X%02X%02X%02X%02X%02X",
 381                  names->mac[0], names->mac[1], names->mac[2],
 382                  names->mac[3], names->mac[4], names->mac[5]);
 383         udev_builtin_hwdb_lookup(dev, str, test);
 384         return 0;
 385 }
 386
 387 static int builtin_net_id(struct udev_device *dev, int argc, char *argv[], bool test) {
 388         const char *s;
 389         const char *p;
 390         unsigned int i;
 391         const char *devtype;
 392         const char *prefix = "en";
 393         struct netnames names;
 394         int err;
 395
 396         /* handle only ARPHRD_ETHER devices */
 397         s = udev_device_get_sysattr_value(dev, "type");
 398         if (!s)
 399                 return EXIT_FAILURE;
 400         i = strtoul(s, NULL, 0);
 401         if (i != 1)
 402                 return 0;
 403
 404         /* skip stacked devices, like VLANs, ... */
 405         s = udev_device_get_sysattr_value(dev, "ifindex");
 406         if (!s)
 407                 return EXIT_FAILURE;
 408         p = udev_device_get_sysattr_value(dev, "iflink");
 409         if (!p)
 410                 return EXIT_FAILURE;
 411         if (strcmp(s, p) != 0)
 412                 return 0;
 413
 414         devtype = udev_device_get_devtype(dev);
 415         if (devtype) {
 416                 if (streq("wlan", devtype))
 417                         prefix = "wl";
 418                 else if (streq("wwan", devtype))
 419                         prefix = "ww";
 420         }
 421
 422         zero(names);
 423         err = names_mac(dev, &names);
 424         if (err >= 0 && names.mac_valid) {
 425                 char str[IFNAMSIZ];
 426
 427                 snprintf(str, sizeof(str), "%sx%02x%02x%02x%02x%02x%02x", prefix,
 428                          names.mac[0], names.mac[1], names.mac[2],
 429                          names.mac[3], names.mac[4], names.mac[5]);
 430                 udev_builtin_add_property(dev, test, "ID_NET_NAME_MAC", str);
 431
 432                 ieee_oui(dev, &names, test);
 433         }
 434
 435         /* get PCI based path names, we compose only PCI based paths */
 436         err = names_pci(dev, &names);
 437         if (err < 0)
 438                 goto out;
 439
 440         /* plain PCI device */
 441         if (names.type == NET_PCI) {
 442                 char str[IFNAMSIZ];
 443
 444                 if (names.pci_onboard[0])
 445                         if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_onboard) < (int)sizeof(str))
 446                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_ONBOARD", str);
 447
 448                 if (names.pci_onboard_label)
 449                         if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_onboard_label) < (int)sizeof(str))
 450                                 udev_builtin_add_property(dev, test, "ID_NET_LABEL_ONBOARD", str);
 451
 452                 if (names.pci_path[0])
 453                         if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_path) < (int)sizeof(str))
 454                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
 455
 456                 if (names.pci_slot[0])
 457                         if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_slot) < (int)sizeof(str))
 458                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
 459                 goto out;
 460         }
 461
 462         /* USB device */
 463         err = names_usb(dev, &names);
 464         if (err >= 0 && names.type == NET_USB) {
 465                 char str[IFNAMSIZ];
 466
 467                 if (names.pci_path[0])
 468                         if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_path, names.usb_ports) < (int)sizeof(str))
 469                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
 470
 471                 if (names.pci_slot[0])
 472                         if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_slot, names.usb_ports) < (int)sizeof(str))
 473                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
 474                 goto out;
 475         }
 476
 477         /* Broadcom bus */
 478         err = names_bcma(dev, &names);
 479         if (err >= 0 && names.type == NET_BCMA) {
 480                 char str[IFNAMSIZ];
 481
 482                 if (names.pci_path[0])
 483                         if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_path, names.bcma_core) < (int)sizeof(str))
 484                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
 485
 486                 if (names.pci_slot[0])
 487                         if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_slot, names.bcma_core) < (int)sizeof(str))
 488                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
 489                 goto out;
 490         }
 491
 492 out:
 493         return EXIT_SUCCESS;
 494 }
 495
 496 const struct udev_builtin udev_builtin_net_id = {
 497         .name = "net_id",
 498         .cmd = builtin_net_id,
 499         .help = "network device properties",
 500 };