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Diffstat (limited to 'src/shared/netif-naming-scheme.h')
| -rw-r--r-- | src/shared/netif-naming-scheme.h | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/src/shared/netif-naming-scheme.h b/src/shared/netif-naming-scheme.h new file mode 100644 index 0000000..3f7be08 --- /dev/null +++ b/src/shared/netif-naming-scheme.h @@ -0,0 +1,97 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +#include <stdbool.h> + +#include "macro.h" + +/* So here's the deal: net_id is supposed to be an exercise in providing stable names for network devices. However, we + * also want to keep updating the naming scheme used in future versions of net_id. These two goals of course are + * contradictory: on one hand we want things to not change and on the other hand we want them to improve. Our way out + * of this dilemma is to introduce the "naming scheme" concept: each time we improve the naming logic we define a new + * flag for it. Then, we keep a list of schemes, each identified by a name associated with the flags it implements. Via + * a kernel command line and environment variable we then allow the user to pick the scheme they want us to follow: + * installers could "freeze" the used scheme at the moment of installation this way. + * + * Developers: each time you tweak the naming logic here, define a new flag below, and condition the tweak with + * it. Each time we do a release we'll then add a new scheme entry and include all newly defined flags. + * + * Note that this is only half a solution to the problem though: not only udev/net_id gets updated all the time, the + * kernel gets too. And thus a kernel that previously didn't expose some sysfs attribute we look for might eventually + * do, and thus affect our naming scheme too. Thus, enforcing a naming scheme will make interfacing more stable across + * OS versions, but not fully stabilize them. */ +typedef enum NamingSchemeFlags { + /* First, the individual features */ + NAMING_SR_IOV_V = 1 << 0, /* Use "v" suffix for SR-IOV, see 609948c7043a */ + NAMING_NPAR_ARI = 1 << 1, /* Use NPAR "ARI", see 6bc04997b6ea */ + NAMING_INFINIBAND = 1 << 2, /* Use "ib" prefix for infiniband, see 938d30aa98df */ + NAMING_ZERO_ACPI_INDEX = 1 << 3, /* Use zero acpi_index field, see d81186ef4f6a */ + NAMING_ALLOW_RERENAMES = 1 << 4, /* Allow re-renaming of devices, see #9006 */ + NAMING_STABLE_VIRTUAL_MACS = 1 << 5, /* Use device name to generate MAC, see 6d3646406560 */ + NAMING_NETDEVSIM = 1 << 6, /* Generate names for netdevsim devices, see eaa9d507d855 */ + NAMING_LABEL_NOPREFIX = 1 << 7, /* Don't prepend ID_NET_LABEL_ONBOARD with interface type prefix */ + NAMING_NSPAWN_LONG_HASH = 1 << 8, /* Shorten nspawn interfaces by including 24bit hash, instead of simple truncation */ + NAMING_BRIDGE_NO_SLOT = 1 << 9, /* Don't use PCI hotplug slot information if the corresponding device is a PCI bridge */ + NAMING_SLOT_FUNCTION_ID = 1 << 10, /* Use function_id if present to identify PCI hotplug slots */ + NAMING_16BIT_INDEX = 1 << 11, /* Allow full 16-bit for the onboard index */ + NAMING_REPLACE_STRICTLY = 1 << 12, /* Use udev_replace_ifname() for NAME= rule */ + NAMING_XEN_VIF = 1 << 13, /* Generate names for Xen netfront devices */ + NAMING_BRIDGE_MULTIFUNCTION_SLOT = 1 << 14, /* Use PCI hotplug slot information associated with bridge, but only if PCI device is multifunction. + * This is disabled since v255, as it seems not to work at least for some setups. See issue #28929. */ + NAMING_DEVICETREE_ALIASES = 1 << 15, /* Generate names from devicetree aliases */ + NAMING_USB_HOST = 1 << 16, /* Generate names for usb host */ + NAMING_SR_IOV_R = 1 << 17, /* Use "r" suffix for SR-IOV VF representors */ + + /* And now the masks that combine the features above */ + NAMING_V238 = 0, + NAMING_V239 = NAMING_V238 | NAMING_SR_IOV_V | NAMING_NPAR_ARI, + NAMING_V240 = NAMING_V239 | NAMING_INFINIBAND | NAMING_ZERO_ACPI_INDEX | NAMING_ALLOW_RERENAMES, + NAMING_V241 = NAMING_V240 | NAMING_STABLE_VIRTUAL_MACS, + NAMING_V243 = NAMING_V241 | NAMING_NETDEVSIM | NAMING_LABEL_NOPREFIX, + NAMING_V245 = NAMING_V243 | NAMING_NSPAWN_LONG_HASH, + NAMING_V247 = NAMING_V245 | NAMING_BRIDGE_NO_SLOT, + NAMING_V249 = NAMING_V247 | NAMING_SLOT_FUNCTION_ID | NAMING_16BIT_INDEX | NAMING_REPLACE_STRICTLY, + NAMING_V250 = NAMING_V249 | NAMING_XEN_VIF, + NAMING_V251 = NAMING_V250 | NAMING_BRIDGE_MULTIFUNCTION_SLOT, + NAMING_V252 = NAMING_V251 | NAMING_DEVICETREE_ALIASES, + NAMING_V253 = NAMING_V252 | NAMING_USB_HOST, + NAMING_V254 = NAMING_V253 | NAMING_SR_IOV_R, /* Despite the name, "v254" is NOT the default scheme + * for systemd version 254. It was added in a follow-up + * patch later. NAMING_SR_IOV_R is enabled by default in + * systemd version 255, naming scheme "v255". */ + NAMING_V255 = NAMING_V254 & ~NAMING_BRIDGE_MULTIFUNCTION_SLOT, + + EXTRA_NET_NAMING_SCHEMES + + _NAMING_SCHEME_FLAGS_INVALID = -EINVAL, +} NamingSchemeFlags; + +typedef struct NamingScheme { + const char *name; + NamingSchemeFlags flags; +} NamingScheme; + +const NamingScheme* naming_scheme_from_name(const char *name); +const NamingScheme* naming_scheme(void); + +static inline bool naming_scheme_has(NamingSchemeFlags flags) { + return FLAGS_SET(naming_scheme()->flags, flags); +} + +typedef enum NamePolicy { + NAMEPOLICY_KERNEL, + NAMEPOLICY_KEEP, + NAMEPOLICY_DATABASE, + NAMEPOLICY_ONBOARD, + NAMEPOLICY_SLOT, + NAMEPOLICY_PATH, + NAMEPOLICY_MAC, + _NAMEPOLICY_MAX, + _NAMEPOLICY_INVALID = -EINVAL, +} NamePolicy; + +const char *name_policy_to_string(NamePolicy p) _const_; +NamePolicy name_policy_from_string(const char *p) _pure_; + +const char *alternative_names_policy_to_string(NamePolicy p) _const_; +NamePolicy alternative_names_policy_from_string(const char *p) _pure_; |