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>][...][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 };
  98
  99 struct netnames {
 100         enum netname_type type;
 101
 102         uint8_t mac[6];
 103         bool mac_valid;
 104
 105         struct udev_device *pcidev;
 106         char pci_slot[IFNAMSIZ];
 107         char pci_path[IFNAMSIZ];
 108         char pci_onboard[IFNAMSIZ];
 109         const char *pci_onboard_label;
 110
 111         struct udev_device *usbdev;
 112         char usb_ports[IFNAMSIZ];
 113 };
 114
 115 /* retrieve on-board index number and label from firmware */
 116 static int dev_pci_onboard(struct udev_device *dev, struct netnames *names) {
 117         const char *index;
 118         int idx;
 119
 120         /* ACPI _DSM  -- device specific method for naming a PCI or PCI Express device */
 121         index = udev_device_get_sysattr_value(names->pcidev, "acpi_index");
 122         /* SMBIOS type 41 -- Onboard Devices Extended Information */
 123         if (!index)
 124                 index = udev_device_get_sysattr_value(names->pcidev, "index");
 125         if (!index)
 126                 return -ENOENT;
 127         idx = strtoul(index, NULL, 0);
 128         if (idx <= 0)
 129                 return -EINVAL;
 130         snprintf(names->pci_onboard, sizeof(names->pci_onboard), "o%d", idx);
 131
 132         names->pci_onboard_label = udev_device_get_sysattr_value(names->pcidev, "label");
 133         return 0;
 134 }
 135
 136 /* read the 256 bytes PCI configuration space to check the multi-function bit */
 137 static bool is_pci_singlefunction(struct udev_device *dev) {
 138         char filename[256];
 139         FILE *f;
 140         char config[64];
 141         bool single = false;
 142
 143         snprintf(filename, sizeof(filename), "%s/config", udev_device_get_syspath(dev));
 144         f = fopen(filename, "re");
 145         if (!f)
 146                 goto out;
 147         if (fread(&config, sizeof(config), 1, f) != 1)
 148                 goto out;
 149
 150         /* bit 0-6 header type, bit 7 multi/single function device */
 151         if ((config[PCI_HEADER_TYPE] & 0x80) == 0)
 152                 single = true;
 153 out:
 154         fclose(f);
 155         return single;
 156 }
 157
 158 static int dev_pci_slot(struct udev_device *dev, struct netnames *names) {
 159         struct udev *udev = udev_device_get_udev(names->pcidev);
 160         unsigned int bus;
 161         unsigned int slot;
 162         unsigned int func;
 163         struct udev_device *pci = NULL;
 164         char slots[256];
 165         DIR *dir;
 166         struct dirent *dent;
 167         char str[256];
 168         int hotplug_slot = 0;
 169         int err = 0;
 170
 171         /* compose a name based on the raw kernel's PCI bus, slot numbers */
 172         if (sscanf(udev_device_get_sysname(names->pcidev), "0000:%x:%x.%d", &bus, &slot, &func) != 3)
 173                 return -ENOENT;
 174         if (func == 0 && is_pci_singlefunction(names->pcidev))
 175                 snprintf(names->pci_path, sizeof(names->pci_path), "p%ds%d", bus, slot);
 176         else
 177                 snprintf(names->pci_path, sizeof(names->pci_path), "p%ds%df%d", bus, slot, func);
 178
 179         /* ACPI _SUN  -- slot user number */
 180         pci = udev_device_new_from_subsystem_sysname(udev, "subsystem", "pci");
 181         if (!pci) {
 182                 err = -ENOENT;
 183                 goto out;
 184         }
 185         snprintf(slots, sizeof(slots), "%s/slots", udev_device_get_syspath(pci));
 186         dir = opendir(slots);
 187         if (!dir) {
 188                 err = -errno;
 189                 goto out;
 190         }
 191
 192         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 193                 int i;
 194                 char *rest;
 195                 char *address;
 196
 197                 if (dent->d_name[0] == '.')
 198                         continue;
 199                 i = strtol(dent->d_name, &rest, 10);
 200                 if (rest[0] != '\0')
 201                         continue;
 202                 if (i < 1)
 203                         continue;
 204                 snprintf(str, sizeof(str), "%s/%s/address", slots, dent->d_name);
 205                 if (read_one_line_file(str, &address) >= 0) {
 206                         /* match slot address with device by stripping the function */
 207                         if (strncmp(address, udev_device_get_sysname(names->pcidev), strlen(address)) == 0)
 208                                 hotplug_slot = i;
 209                         free(address);
 210                 }
 211
 212                 if (hotplug_slot > 0)
 213                         break;
 214         }
 215         closedir(dir);
 216
 217         if (hotplug_slot > 0) {
 218                 if (func == 0 && is_pci_singlefunction(names->pcidev))
 219                         snprintf(names->pci_slot, sizeof(names->pci_slot), "s%d", hotplug_slot);
 220                 else
 221                         snprintf(names->pci_slot, sizeof(names->pci_slot), "s%df%d", hotplug_slot, func);
 222         }
 223 out:
 224         udev_device_unref(pci);
 225         return err;
 226 }
 227
 228 static int names_pci(struct udev_device *dev, struct netnames *names) {
 229         struct udev_device *parent;
 230
 231         parent = udev_device_get_parent(dev);
 232         if (!parent)
 233                 return -ENOENT;
 234         /* check if our direct parent is a PCI device with no other bus in-between */
 235         if (streq("pci", udev_device_get_subsystem(parent))) {
 236                 names->type = NET_PCI;
 237                 names->pcidev = parent;
 238         } else {
 239                 names->pcidev = udev_device_get_parent_with_subsystem_devtype(dev, "pci", NULL);
 240                 if (!names->pcidev)
 241                         return -ENOENT;
 242         }
 243         dev_pci_onboard(dev, names);
 244         dev_pci_slot(dev, names);
 245         return 0;
 246 }
 247
 248 static int names_usb(struct udev_device *dev, struct netnames *names) {
 249         char name[256];
 250         char *ports;
 251         char *config;
 252         char *interf;
 253         size_t l;
 254         char *s;
 255
 256         names->usbdev = udev_device_get_parent_with_subsystem_devtype(dev, "usb", "usb_interface");
 257         if (!names->usbdev)
 258                 return -ENOENT;
 259
 260         /* get USB port number chain, configuration, interface */
 261         util_strscpy(name, sizeof(name), udev_device_get_sysname(names->usbdev));
 262         s = strchr(name, '-');
 263         if (!s)
 264                 return -EINVAL;
 265         ports = s+1;
 266
 267         s = strchr(ports, ':');
 268         if (!s)
 269                 return -EINVAL;
 270         s[0] = '\0';
 271         config = s+1;
 272
 273         s = strchr(config, '.');
 274         if (!s)
 275                 return -EINVAL;
 276         s[0] = '\0';
 277         interf = s+1;
 278
 279         /* prefix every port number in the chain with "u"*/
 280         s = ports;
 281         while ((s = strchr(s, '.')))
 282                 s[0] = 'u';
 283         s = names->usb_ports;
 284         l = util_strpcpyl(&s, sizeof(names->usb_ports), "u", ports, NULL);
 285
 286         /* append USB config number, suppress the common config == 1 */
 287         if (!streq(config, "1"))
 288                 l = util_strpcpyl(&s, sizeof(names->usb_ports), "c", config, NULL);
 289
 290         /* append USB interface number, suppress the interface == 0 */
 291         if (!streq(interf, "0"))
 292                 l = util_strpcpyl(&s, sizeof(names->usb_ports), "i", interf, NULL);
 293         if (l == 0)
 294                 return -ENAMETOOLONG;
 295
 296         names->type = NET_USB;
 297         return 0;
 298 }
 299
 300 static int names_mac(struct udev_device *dev, struct netnames *names) {
 301         const char *s;
 302         unsigned int i;
 303         unsigned int a1, a2, a3, a4, a5, a6;
 304
 305         /* check for NET_ADDR_PERM, skip random MAC addresses */
 306         s = udev_device_get_sysattr_value(dev, "addr_assign_type");
 307         if (!s)
 308                 return EXIT_FAILURE;
 309         i = strtoul(s, NULL, 0);
 310         if (i != 0)
 311                 return 0;
 312
 313         s = udev_device_get_sysattr_value(dev, "address");
 314         if (!s)
 315                 return -ENOENT;
 316         if (sscanf(s, "%x:%x:%x:%x:%x:%x", &a1, &a2, &a3, &a4, &a5, &a6) != 6)
 317                 return -EINVAL;
 318
 319         /* skip empty MAC addresses */
 320         if (a1 + a2 + a3 + a4 + a5 + a6 == 0)
 321                 return -EINVAL;
 322
 323         names->mac[0] = a1;
 324         names->mac[1] = a2;
 325         names->mac[2] = a3;
 326         names->mac[3] = a4;
 327         names->mac[4] = a5;
 328         names->mac[5] = a6;
 329         names->mac_valid = true;
 330         return 0;
 331 }
 332
 333 /* IEEE Organizationally Unique Identifier vendor string */
 334 static int ieee_oui(struct udev_device *dev, struct netnames *names, bool test) {
 335         char str[32];
 336
 337         if (!names->mac_valid)
 338                 return -ENOENT;
 339         /* skip commonly misused 00:00:00 (Xerox) prefix */
 340         if (memcmp(names->mac, "\0\0\0", 3) == 0)
 341                 return -EINVAL;
 342         snprintf(str, sizeof(str), "OUI:%02X%02X%02X%02X%02X%02X",
 343                  names->mac[0], names->mac[1], names->mac[2],
 344                  names->mac[3], names->mac[4], names->mac[5]);
 345         udev_builtin_hwdb_lookup(dev, str, test);
 346         return 0;
 347 }
 348
 349 static int builtin_net_id(struct udev_device *dev, int argc, char *argv[], bool test) {
 350         const char *s;
 351         unsigned int i;
 352         const char *devtype;
 353         const char *prefix = "en";
 354         struct netnames names;
 355         int err;
 356
 357         /* handle only ARPHRD_ETHER devices */
 358         s = udev_device_get_sysattr_value(dev, "type");
 359         if (!s)
 360                 return EXIT_FAILURE;
 361         i = strtoul(s, NULL, 0);
 362         if (i != 1)
 363                 return 0;
 364
 365         devtype = udev_device_get_devtype(dev);
 366         if (devtype) {
 367                 if (streq("wlan", devtype))
 368                         prefix = "wl";
 369                 else if (streq("wwan", devtype))
 370                         prefix = "ww";
 371         }
 372
 373         zero(names);
 374         err = names_mac(dev, &names);
 375         if (err >= 0 && names.mac_valid) {
 376                 char str[IFNAMSIZ];
 377
 378                 snprintf(str, sizeof(str), "%sx%02x%02x%02x%02x%02x%02x", prefix,
 379                          names.mac[0], names.mac[1], names.mac[2],
 380                          names.mac[3], names.mac[4], names.mac[5]);
 381                 udev_builtin_add_property(dev, test, "ID_NET_NAME_MAC", str);
 382
 383                 ieee_oui(dev, &names, test);
 384         }
 385
 386         /* get PCI based path names, we compose only PCI based paths */
 387         err = names_pci(dev, &names);
 388         if (err < 0)
 389                 goto out;
 390
 391         /* plain PCI device */
 392         if (names.type == NET_PCI) {
 393                 char str[IFNAMSIZ];
 394
 395                 if (names.pci_onboard[0])
 396                         if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_onboard) < (int)sizeof(str))
 397                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_ONBOARD", str);
 398
 399                 if (names.pci_onboard_label)
 400                         if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_onboard_label) < (int)sizeof(str))
 401                                 udev_builtin_add_property(dev, test, "ID_NET_LABEL_ONBOARD", str);
 402
 403                 if (names.pci_path[0])
 404                         if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_path) < (int)sizeof(str))
 405                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
 406
 407                 if (names.pci_slot[0])
 408                         if (snprintf(str, sizeof(str), "%s%s", prefix, names.pci_slot) < (int)sizeof(str))
 409                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
 410                 goto out;
 411         }
 412
 413         /* USB device */
 414         err = names_usb(dev, &names);
 415         if (err >= 0 && names.type == NET_USB) {
 416                 char str[IFNAMSIZ];
 417
 418                 if (names.pci_path[0])
 419                         if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_path, names.usb_ports) < (int)sizeof(str))
 420                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
 421
 422                 if (names.pci_slot[0])
 423                         if (snprintf(str, sizeof(str), "%s%s%s", prefix, names.pci_slot, names.usb_ports) < (int)sizeof(str))
 424                                 udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
 425         }
 426 out:
 427         return EXIT_SUCCESS;
 428 }
 429
 430 const struct udev_builtin udev_builtin_net_id = {
 431         .name = "net_id",
 432         .cmd = builtin_net_id,
 433         .help = "network device properties",
 434 };