summaryrefslogtreecommitdiff
path: root/src/udev/udev-builtin-net_id.c
blob: fd84e6e24fbc9c21f045f997a77b6bc24792e4df (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
/***
  This file is part of systemd.

  Copyright 2012 Kay Sievers <kay@vrfy.org>

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  systemd is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

/*
 * predictable network interface device names based on:
 *  - firmware/bios-provided index numbers for on-board devices
 *  - firmware-provided pci-express hotplug slot index number
 *  - physical/geographical location of the hardware
 *  - the interface's MAC address
 *
 * two character prefixes based on the type of interface:
 *   en -- ethernet
 *   wl -- wlan
 *   ww -- wwan
 *
 * type of names:
 *   o<index>                   -- on-board device index number
 *   s<slot>[f<function>]       -- hotplug slot index number
 *   x<MAC>                     -- MAC address
 *   p<bus>s<slot>[f<function>] -- PCI geographical location
 *
 * All multi-function devices will carry the [f<function>] number in the
 * device name, including the function 0 device.
 *
 * examples:
 *   ID_NET_NAME_ONBOARD=eno1
 *   ID_NET_NAME_SLOT=ens1
 *   ID_NET_NAME_SLOT=ens2f0
 *   ID_NET_NAME_SLOT=ens2f1
 *   ID_NET_NAME_MAC=enxf0def180d479
 *   ID_NET_NAME_PATH=enp0s25
 *   ID_NET_NAME_PATH=enp19s3f0
 *   ID_NET_NAME_PATH=enp19s3f1
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <linux/pci_regs.h>

#include "udev.h"

/* retrieve on-board index number and label from firmware */
static int dev_pci_onboard(struct udev_device *dev, struct udev_device *parent, const char *prefix, bool test) {
        const char *index;
        int idx;
        const char *label;
        char s[16];
        int err;

        /* ACPI _DSM  -- device specific method for naming a PCI or PCI Express device */
        index = udev_device_get_sysattr_value(parent, "acpi_index");
        /* SMBIOS type 41 -- Onboard Devices Extended Information */
        if (!index)
                index = udev_device_get_sysattr_value(parent, "index");
        if (!index)
                return -ENOENT;
        idx = strtoul(index, NULL, 0);
        if (idx <= 0)
                return -EINVAL;
        snprintf(s, sizeof(s), "%so%d", prefix, idx);
        err = udev_builtin_add_property(dev, test, "ID_NET_NAME_ONBOARD", s);
        if (err < 0)
                return err;

        label = udev_device_get_sysattr_value(parent, "label");
        if (label) {
                err = udev_builtin_add_property(dev, test, "ID_NET_LABEL_ONBOARD", label);
                if (err < 0)
                        return err;
        }
        return 0;
}

/* read the 256 bytes PCI configuration space to check for multi-function */
static bool is_pci_singlefunction(struct udev_device *dev) {
        char filename[256];
        FILE *f;
        char config[256];
        bool single = false;

        snprintf(filename, sizeof(filename), "%s/config", udev_device_get_syspath(dev));
        f = fopen(filename, "re");
        if (!f)
                goto out;
        if (fread(&config, sizeof(config), 1, f) != 1)
                goto out;

        /* bit 0-6 header type, bit 7 multi/single function device */
        if ((config[PCI_HEADER_TYPE] & 0x80) == 0)
                single = true;
out:
        fclose(f);
        return single;
}

static int dev_pci_slot(struct udev_device *dev, struct udev_device *parent, const char *prefix, bool test) {
        struct udev *udev = udev_device_get_udev(dev);
        unsigned int bus;
        unsigned int slot;
        unsigned int func;
        struct udev_device *pci = NULL;
        char slots[256];
        DIR *dir;
        struct dirent *dent;
        char str[256];
        int hotplug_slot = 0;
        int err = 0;

        /* compose a name based on the raw kernel's PCI bus, slot numbers */
        if (sscanf(udev_device_get_sysname(parent), "0000:%x:%x.%d", &bus, &slot, &func) != 3)
                return -ENOENT;
        if (func == 0 && is_pci_singlefunction(parent))
                snprintf(str, sizeof(str), "%sp%ds%d", prefix, bus, slot);
        else
                snprintf(str, sizeof(str), "%sp%ds%df%d", prefix, bus, slot, func);
        err = udev_builtin_add_property(dev, test, "ID_NET_NAME_PATH", str);
        if (err < 0)
                return err;

        /* ACPI _SUN  -- slot user number */
        pci = udev_device_new_from_subsystem_sysname(udev, "subsystem", "pci");
        if (!pci) {
                err = -ENOENT;
                goto out;
        }
        snprintf(slots, sizeof(slots), "%s/slots", udev_device_get_syspath(pci));
        dir = opendir(slots);
        if (!dir) {
                err = -errno;
                goto out;
        }

        for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
                int i;
                char *rest;
                char *address;

                if (dent->d_name[0] == '.')
                        continue;
                i = strtol(dent->d_name, &rest, 10);
                if (rest[0] != '\0')
                        continue;
                if (i < 1)
                        continue;
                snprintf(str, sizeof(str), "%s/%s/address", slots, dent->d_name);
                if (read_one_line_file(str, &address) >= 0) {
                        /* match slot address with device by stripping the function */
                        if (strncmp(address, udev_device_get_sysname(parent), strlen(address)) == 0)
                                hotplug_slot = i;
                        free(address);
                }

                if (hotplug_slot > 0)
                        break;
        }
        closedir(dir);

        if (hotplug_slot > 0) {
                if (func == 0 && is_pci_singlefunction(parent))
                        snprintf(str, sizeof(str), "%ss%d", prefix, hotplug_slot);
                else
                        snprintf(str, sizeof(str), "%ss%df%d", prefix, hotplug_slot, func);
                err = udev_builtin_add_property(dev, test, "ID_NET_NAME_SLOT", str);
        }
out:
        udev_device_unref(pci);
        return err;
}

static int dev_pci(struct udev_device *dev, const char *prefix, bool test) {
        struct udev_device *parent;

        /* skip other buses than direct PCI parents */
        parent = udev_device_get_parent(dev);
        if (!parent || !streq("pci", udev_device_get_subsystem(parent)))
                return -ENOENT;

        dev_pci_onboard(dev, parent, prefix, test);
        dev_pci_slot(dev, parent, prefix, test);
        return 0;
}

static int dev_mac(struct udev_device *dev, const char *prefix, bool test) {
        const char *s;
        unsigned int i;
        unsigned int a1, a2, a3, a4, a5, a6;
        char str[16];

        /* check for NET_ADDR_PERM, skip random MAC addresses */
        s = udev_device_get_sysattr_value(dev, "addr_assign_type");
        if (!s)
                return EXIT_FAILURE;
        i = strtoul(s, NULL, 0);
        if (i != 0)
                return 0;

        s = udev_device_get_sysattr_value(dev, "address");
        if (!s)
                return -ENOENT;
        if (sscanf(s, "%x:%x:%x:%x:%x:%x", &a1, &a2, &a3, &a4, &a5, &a6) != 6)
                return -EINVAL;

        /* skip empty MAC addresses */
        if (a1 + a2 + a3 + a4 + a5 + a6 == 0)
                return -EINVAL;

        /* add IEEE Organizationally Unique Identifier */
        if (a1 + a2 + a3 > 0) {
                snprintf(str, sizeof(str), "OUI:%02X%02X%02X", a1, a2, a3);
                udev_builtin_hwdb_lookup(dev, str, test);
        }

        snprintf(str, sizeof(str), "%sx%02x%02x%02x%02x%02x%02x", prefix, a1, a2, a3, a4, a5, a6);
        return udev_builtin_add_property(dev, test, "ID_NET_NAME_MAC", str);
}

static int builtin_net_id(struct udev_device *dev, int argc, char *argv[], bool test) {
        const char *s;
        unsigned int i;
        const char *devtype;
        const char *prefix = "en";

        /* handle only ARPHRD_ETHER devices */
        s = udev_device_get_sysattr_value(dev, "type");
        if (!s)
                return EXIT_FAILURE;
        i = strtoul(s, NULL, 0);
        if (i != 1)
                return 0;

        devtype = udev_device_get_devtype(dev);
        if (devtype) {
                if (streq("wlan", devtype))
                        prefix = "wl";
                else if (streq("wwan", devtype))
                        prefix = "ww";
        }

        dev_pci(dev, prefix, test);
        dev_mac(dev, prefix, test);
        return EXIT_SUCCESS;
}

const struct udev_builtin udev_builtin_net_id = {
        .name = "net_id",
        .cmd = builtin_net_id,
        .help = "network device properties",
};