1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
2 #pragma once
3
4 #include <stdbool.h>
5
6 #include "macro.h"
7
8 /* So here's the deal: net_id is supposed to be an exercise in providing stable names for network devices. However, we
9 * also want to keep updating the naming scheme used in future versions of net_id. These two goals of course are
10 * contradictory: on one hand we want things to not change and on the other hand we want them to improve. Our way out
11 * of this dilemma is to introduce the "naming scheme" concept: each time we improve the naming logic we define a new
12 * flag for it. Then, we keep a list of schemes, each identified by a name associated with the flags it implements. Via
13 * a kernel command line and environment variable we then allow the user to pick the scheme they want us to follow:
14 * installers could "freeze" the used scheme at the moment of installation this way.
15 *
16 * Developers: each time you tweak the naming logic here, define a new flag below, and condition the tweak with
17 * it. Each time we do a release we'll then add a new scheme entry and include all newly defined flags.
18 *
19 * Note that this is only half a solution to the problem though: not only udev/net_id gets updated all the time, the
20 * kernel gets too. And thus a kernel that previously didn't expose some sysfs attribute we look for might eventually
21 * do, and thus affect our naming scheme too. Thus, enforcing a naming scheme will make interfacing more stable across
22 * OS versions, but not fully stabilize them. */
23 typedef enum NamingSchemeFlags {
24 /* First, the individual features */
25 NAMING_SR_IOV_V = 1 << 0, /* Use "v" suffix for SR-IOV, see 609948c7043a */
26 NAMING_NPAR_ARI = 1 << 1, /* Use NPAR "ARI", see 6bc04997b6ea */
27 NAMING_INFINIBAND = 1 << 2, /* Use "ib" prefix for infiniband, see 938d30aa98df */
28 NAMING_ZERO_ACPI_INDEX = 1 << 3, /* Use zero acpi_index field, see d81186ef4f6a */
29 NAMING_ALLOW_RERENAMES = 1 << 4, /* Allow re-renaming of devices, see #9006 */
30 NAMING_STABLE_VIRTUAL_MACS = 1 << 5, /* Use device name to generate MAC, see 6d3646406560 */
31 NAMING_NETDEVSIM = 1 << 6, /* Generate names for netdevsim devices, see eaa9d507d855 */
32 NAMING_LABEL_NOPREFIX = 1 << 7, /* Don't prepend ID_NET_LABEL_ONBOARD with interface type prefix */
33 NAMING_NSPAWN_LONG_HASH = 1 << 8, /* Shorten nspawn interfaces by including 24bit hash, instead of simple truncation */
34 NAMING_BRIDGE_NO_SLOT = 1 << 9, /* Don't use PCI hotplug slot information if the corresponding device is a PCI bridge */
35 NAMING_SLOT_FUNCTION_ID = 1 << 10, /* Use function_id if present to identify PCI hotplug slots */
36 NAMING_16BIT_INDEX = 1 << 11, /* Allow full 16-bit for the onboard index */
37 NAMING_REPLACE_STRICTLY = 1 << 12, /* Use udev_replace_ifname() for NAME= rule */
38 NAMING_XEN_VIF = 1 << 13, /* Generate names for Xen netfront devices */
39 NAMING_BRIDGE_MULTIFUNCTION_SLOT = 1 << 14, /* Use PCI hotplug slot information associated with bridge, but only if PCI device is multifunction */
40
41 /* And now the masks that combine the features above */
42 NAMING_V238 = 0,
43 NAMING_V239 = NAMING_V238 | NAMING_SR_IOV_V | NAMING_NPAR_ARI,
44 NAMING_V240 = NAMING_V239 | NAMING_INFINIBAND | NAMING_ZERO_ACPI_INDEX | NAMING_ALLOW_RERENAMES,
45 NAMING_V241 = NAMING_V240 | NAMING_STABLE_VIRTUAL_MACS,
46 NAMING_V243 = NAMING_V241 | NAMING_NETDEVSIM | NAMING_LABEL_NOPREFIX,
47 NAMING_V245 = NAMING_V243 | NAMING_NSPAWN_LONG_HASH,
48 NAMING_V247 = NAMING_V245 | NAMING_BRIDGE_NO_SLOT,
49 NAMING_V249 = NAMING_V247 | NAMING_SLOT_FUNCTION_ID | NAMING_16BIT_INDEX | NAMING_REPLACE_STRICTLY,
50 NAMING_V250 = NAMING_V249 | NAMING_XEN_VIF,
51 NAMING_V251 = NAMING_V250 | NAMING_BRIDGE_MULTIFUNCTION_SLOT,
52
53 EXTRA_NET_NAMING_SCHEMES
54
55 _NAMING_SCHEME_FLAGS_INVALID = -EINVAL,
56 } NamingSchemeFlags;
57
58 typedef struct NamingScheme {
59 const char *name;
60 NamingSchemeFlags flags;
61 } NamingScheme;
62
63 const NamingScheme* naming_scheme_from_name(const char *name);
64 const NamingScheme* naming_scheme(void);
65
naming_scheme_has(NamingSchemeFlags flags)66 static inline bool naming_scheme_has(NamingSchemeFlags flags) {
67 return FLAGS_SET(naming_scheme()->flags, flags);
68 }
69
70 typedef enum NamePolicy {
71 NAMEPOLICY_KERNEL,
72 NAMEPOLICY_KEEP,
73 NAMEPOLICY_DATABASE,
74 NAMEPOLICY_ONBOARD,
75 NAMEPOLICY_SLOT,
76 NAMEPOLICY_PATH,
77 NAMEPOLICY_MAC,
78 _NAMEPOLICY_MAX,
79 _NAMEPOLICY_INVALID = -EINVAL,
80 } NamePolicy;
81
82 const char *name_policy_to_string(NamePolicy p) _const_;
83 NamePolicy name_policy_from_string(const char *p) _pure_;
84
85 const char *alternative_names_policy_to_string(NamePolicy p) _const_;
86 NamePolicy alternative_names_policy_from_string(const char *p) _pure_;
87