udev: move naming-scheme bits into their own file

4 files changed, 114 insertions, 98 deletions

diff --git a/src/udev/meson.build b/src/udev/meson.build
index a9d6c6363f..9d3f6d1c56 100644
--- a/src/udev/meson.build
+++ b/src/udev/meson.build
@@ -41,6 +41,8 @@ libudev_core_sources = '''
         net/link-config.h
         net/ethtool-util.c
         net/ethtool-util.h
+        net/naming-scheme.c
+        net/naming-scheme.h
 '''.split()
 
 if conf.get('HAVE_KMOD') == 1
diff --git a/src/udev/net/naming-scheme.c b/src/udev/net/naming-scheme.c
new file mode 100644
index 0000000000..27cede5e2e
--- /dev/null
+++ b/src/udev/net/naming-scheme.c
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#include "alloc-util.h"
+#include "naming-scheme.h"
+#include "proc-cmdline.h"
+#include "string-util.h"
+
+static const NamingScheme naming_schemes[] = {
+        { "v238", NAMING_V238 },
+        { "v239", NAMING_V239 },
+        { "v240", NAMING_V240 },
+        /* … add more schemes here, as the logic to name devices is updated … */
+};
+
+static const NamingScheme* naming_scheme_from_name(const char *name) {
+        size_t i;
+
+        if (streq(name, "latest"))
+                return naming_schemes + ELEMENTSOF(naming_schemes) - 1;
+
+        for (i = 0; i < ELEMENTSOF(naming_schemes); i++)
+                if (streq(naming_schemes[i].name, name))
+                        return naming_schemes + i;
+
+        return NULL;
+}
+
+const NamingScheme* naming_scheme(void) {
+        static const NamingScheme *cache = NULL;
+        _cleanup_free_ char *buffer = NULL;
+        const char *e, *k;
+
+        if (cache)
+                return cache;
+
+        /* Acquire setting from the kernel command line */
+        (void) proc_cmdline_get_key("net.naming-scheme", 0, &buffer);
+
+        /* Also acquire it from an env var */
+        e = getenv("NET_NAMING_SCHEME");
+        if (e) {
+                if (*e == ':') {
+                        /* If prefixed with ':' the kernel cmdline takes precedence */
+                        k = buffer ?: e + 1;
+                } else
+                        k = e; /* Otherwise the env var takes precedence */
+        } else
+                k = buffer;
+
+        if (k) {
+                cache = naming_scheme_from_name(k);
+                if (cache) {
+                        log_info("Using interface naming scheme '%s'.", cache->name);
+                        return cache;
+                }
+
+                log_warning("Unknown interface naming scheme '%s' requested, ignoring.", k);
+        }
+
+        cache = naming_scheme_from_name(DEFAULT_NET_NAMING_SCHEME);
+        assert(cache);
+        log_info("Using default interface naming scheme '%s'.", cache->name);
+
+        return cache;
+}
diff --git a/src/udev/net/naming-scheme.h b/src/udev/net/naming-scheme.h
new file mode 100644
index 0000000000..c7f9505ab7
--- /dev/null
+++ b/src/udev/net/naming-scheme.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <stdbool.h>
+
+#include "macro.h"
+
+/* So here's the deal: net_id is supposed to be an excercise 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 609948c7043a40008b8299529c978ed8e11de8f6*/
+        NAMING_NPAR_ARI        = 1 << 1, /* Use NPAR "ARI", see 6bc04997b6eab35d1cb9fa73889892702c27be09 */
+        NAMING_INFINIBAND      = 1 << 2, /* Use "ib" prefix for infiniband, see 938d30aa98df887797c9e05074a562ddacdcdf5e */
+        NAMING_ZERO_ACPI_INDEX = 1 << 3, /* Allow zero acpi_index field, see d81186ef4f6a888a70f20a1e73a812d6acb9e22f */
+
+        /* 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_SCHEME_FLAGS_INVALID = -1,
+} NamingSchemeFlags;
+
+typedef struct NamingScheme {
+        const char *name;
+        NamingSchemeFlags flags;
+} NamingScheme;
+
+const NamingScheme* naming_scheme(void);
+
+static inline bool naming_scheme_has(NamingSchemeFlags flags) {
+        return FLAGS_SET(naming_scheme()->flags, flags);
+}
diff --git a/src/udev/udev-builtin-net_id.c b/src/udev/udev-builtin-net_id.c
index e4d40b149c..03b281a771 100644
--- a/src/udev/udev-builtin-net_id.c
+++ b/src/udev/udev-builtin-net_id.c
@@ -106,6 +106,7 @@
 #include "fd-util.h"
 #include "fileio.h"
 #include "fs-util.h"
+#include "naming-scheme.h"
 #include "parse-util.h"
 #include "proc-cmdline.h"
 #include "stdio-util.h"
@@ -116,48 +117,6 @@
 
 #define ONBOARD_INDEX_MAX (16*1024-1)
 
-/* So here's the deal: net_id is supposed to be an excercise 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 609948c7043a40008b8299529c978ed8e11de8f6*/
-        NAMING_NPAR_ARI        = 1 << 1, /* Use NPAR "ARI", see 6bc04997b6eab35d1cb9fa73889892702c27be09 */
-        NAMING_INFINIBAND      = 1 << 2, /* Use "ib" prefix for infiniband, see 938d30aa98df887797c9e05074a562ddacdcdf5e */
-        NAMING_ZERO_ACPI_INDEX = 1 << 3, /* Allow zero acpi_index field, see d81186ef4f6a888a70f20a1e73a812d6acb9e22f */
-
-        /* 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_SCHEME_FLAGS_INVALID = -1,
-} NamingSchemeFlags;
-
-typedef struct NamingScheme {
-        const char *name;
-        NamingSchemeFlags flags;
-} NamingScheme;
-
-static const NamingScheme naming_schemes[] = {
-        { "v238", NAMING_V238 },
-        { "v239", NAMING_V239 },
-        { "v240", NAMING_V240 },
-        /* … add more schemes here, as the logic to name devices is updated … */
-};
-
 enum netname_type{
         NET_UNDEF,
         NET_PCI,
@@ -193,62 +152,6 @@ struct virtfn_info {
         char suffix[IFNAMSIZ];
 };
 
-static const NamingScheme* naming_scheme_from_name(const char *name) {
-        size_t i;
-
-        if (streq(name, "latest"))
-                return naming_schemes + ELEMENTSOF(naming_schemes) - 1;
-
-        for (i = 0; i < ELEMENTSOF(naming_schemes); i++)
-                if (streq(naming_schemes[i].name, name))
-                        return naming_schemes + i;
-
-        return NULL;
-}
-
-static const NamingScheme* naming_scheme(void) {
-        static const NamingScheme *cache = NULL;
-        _cleanup_free_ char *buffer = NULL;
-        const char *e, *k;
-
-        if (cache)
-                return cache;
-
-        /* Acquire setting from the kernel command line */
-        (void) proc_cmdline_get_key("net.naming-scheme", 0, &buffer);
-
-        /* Also acquire it from an env var */
-        e = getenv("NET_NAMING_SCHEME");
-        if (e) {
-                if (*e == ':') {
-                        /* If prefixed with ':' the kernel cmdline takes precedence */
-                        k = buffer ?: e + 1;
-                } else
-                        k = e; /* Otherwise the env var takes precedence */
-        } else
-                k = buffer;
-
-        if (k) {
-                cache = naming_scheme_from_name(k);
-                if (cache) {
-                        log_info("Using interface naming scheme '%s'.", cache->name);
-                        return cache;
-                }
-
-                log_warning("Unknown interface naming scheme '%s' requested, ignoring.", k);
-        }
-
-        cache = naming_scheme_from_name(DEFAULT_NET_NAMING_SCHEME);
-        assert(cache);
-        log_info("Using default interface naming scheme '%s'.", cache->name);
-
-        return cache;
-}
-
-static bool naming_scheme_has(NamingSchemeFlags flags) {
-        return FLAGS_SET(naming_scheme()->flags, flags);
-}
-
 /* skip intermediate virtio devices */
 static sd_device *skip_virtio(sd_device *dev) {
         sd_device *parent;