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