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