1 files changed, 107 insertions, 0 deletions
diff --git a/src/shared/netif-naming-scheme.c b/src/shared/netif-naming-scheme.c
new file mode 100644
index 0000000..18748e5
--- /dev/null
+++ b/src/shared/netif-naming-scheme.c
@@ -0,0 +1,107 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "alloc-util.h"
+#include "netif-naming-scheme.h"
+#include "proc-cmdline.h"
+#include "string-util.h"
+#include "string-table.h"
+
+#ifdef _DEFAULT_NET_NAMING_SCHEME_TEST
+/* The primary purpose of this check is to verify that _DEFAULT_NET_NAMING_SCHEME_TEST
+ * is a valid identifier. If an invalid name is given during configuration, this will
+ * fail with a name error. */
+assert_cc(_DEFAULT_NET_NAMING_SCHEME_TEST >= 0);
+#endif
+
+static const NamingScheme naming_schemes[] = {
+        { "v238", NAMING_V238 },
+        { "v239", NAMING_V239 },
+        { "v240", NAMING_V240 },
+        { "v241", NAMING_V241 },
+        { "v243", NAMING_V243 },
+        { "v245", NAMING_V245 },
+        { "v247", NAMING_V247 },
+        { "v249", NAMING_V249 },
+        { "v250", NAMING_V250 },
+        { "v251", NAMING_V251 },
+        { "v252", NAMING_V252 },
+        /* … add more schemes here, as the logic to name devices is updated … */
+
+        EXTRA_NET_NAMING_MAP
+};
+
+const NamingScheme* naming_scheme_from_name(const char *name) {
+        /* "latest" may either be defined explicitly by the extra map, in which case we will find it in
+         * the table like any other name. After iterating through the table, we check for "latest" again,
+         * which means that if not mapped explicitly, it maps to the last defined entry, whatever that is. */
+
+        for (size_t i = 0; i < ELEMENTSOF(naming_schemes); i++)
+                if (streq(naming_schemes[i].name, name))
+                        return naming_schemes + i;
+
+        if (streq(name, "latest"))
+                return naming_schemes + ELEMENTSOF(naming_schemes) - 1;
+
+        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;
+}
+
+static const char* const name_policy_table[_NAMEPOLICY_MAX] = {
+        [NAMEPOLICY_KERNEL] = "kernel",
+        [NAMEPOLICY_KEEP] = "keep",
+        [NAMEPOLICY_DATABASE] = "database",
+        [NAMEPOLICY_ONBOARD] = "onboard",
+        [NAMEPOLICY_SLOT] = "slot",
+        [NAMEPOLICY_PATH] = "path",
+        [NAMEPOLICY_MAC] = "mac",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(name_policy, NamePolicy);
+
+static const char* const alternative_names_policy_table[_NAMEPOLICY_MAX] = {
+        [NAMEPOLICY_DATABASE] = "database",
+        [NAMEPOLICY_ONBOARD] = "onboard",
+        [NAMEPOLICY_SLOT] = "slot",
+        [NAMEPOLICY_PATH] = "path",
+        [NAMEPOLICY_MAC] = "mac",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(alternative_names_policy, NamePolicy);