initrd: accept a zero-byte prefix for BOOTIF

The BOOTIF MAC address can be prefixed with a hardware address
type. Typically it is 01 (for ethernet), but the legacy network module
accepts (and strips) any byte value.

It seems wrong to take any address type without validation. In
addition to "01", also accept a zero type which, according to the
bugzilla below, is used in some configurations to mean "undefined".

While at it, also accept ':' as separator for the first byte.

https://bugzilla.redhat.com/show_bug.cgi?id=1904099
https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/merge_requests/713

2 files changed, 66 insertions, 46 deletions

diff --git a/src/initrd/nmi-cmdline-reader.c b/src/initrd/nmi-cmdline-reader.c
index 7c9982bbff..62891fa2cf 100644
--- a/src/initrd/nmi-cmdline-reader.c
+++ b/src/initrd/nmi-cmdline-reader.c
@@ -1154,14 +1154,21 @@ nmi_cmdline_reader_parse(const char *sysfs_dir, const char *const *argv, char **
         NMConnection *  connection;
         NMSettingWired *s_wired;
         const char *    bootif = bootif_val;
-
-        if (!nm_utils_hwaddr_valid(bootif, ETH_ALEN) && g_str_has_prefix(bootif, "01-")
-            && nm_utils_hwaddr_valid(&bootif[3], ETH_ALEN)) {
-            /*
-             * BOOTIF MAC address can be prefixed with a hardware type identifier.
-             * "01" stays for "wired", no other are known.
-             */
-            bootif += 3;
+        char            prefix[4];
+
+        if (!nm_utils_hwaddr_valid(bootif, ETH_ALEN)) {
+            strncpy(prefix, bootif, 3);
+            prefix[3] = '\0';
+
+            if (NM_IN_STRSET(prefix, "01-", "01:", "00-", "00:")
+                && nm_utils_hwaddr_valid(&bootif[3], ETH_ALEN)) {
+                /*
+                 * BOOTIF MAC address can be prefixed with a hardware type identifier.
+                 * "01" stays for "wired", "00" is also accepted as it means "undefined".
+                 * No others are known.
+                 */
+                bootif += 3;
+            }
         }
 
         connection = reader_get_connection(reader, NULL, NM_SETTING_WIRED_SETTING_NAME, FALSE);
diff --git a/src/initrd/tests/test-cmdline-reader.c b/src/initrd/tests/test-cmdline-reader.c
index 07faf96a1f..a809dff93c 100644
--- a/src/initrd/tests/test-cmdline-reader.c
+++ b/src/initrd/tests/test-cmdline-reader.c
@@ -1952,58 +1952,71 @@ static void
 test_bootif_hwtype(void)
 {
     gs_unref_hashtable GHashTable *connections = NULL;
-    const char *const *ARGV = NM_MAKE_STRV("ip=eth0:dhcp", "BOOTIF=01-00-53-AB-cd-02-03");
+    const char *const *ARGV0  = NM_MAKE_STRV("ip=eth0:dhcp", "BOOTIF=01-00-53-AB-cd-02-03");
+    const char *const *ARGV1  = NM_MAKE_STRV("ip=eth0:dhcp", "BOOTIF=00-00-53-Ab-cD-02-03");
+    const char *const *ARGV[] = {ARGV0, ARGV1};
     NMConnection *     connection;
     NMSettingWired *   s_wired;
     NMSettingIPConfig *s_ip4;
     NMSettingIPConfig *s_ip6;
     gs_free char *     hostname = NULL;
+    guint              i;
 
-    connections = nmi_cmdline_reader_parse(TEST_INITRD_DIR "/sysfs", ARGV, &hostname);
-    g_assert(connections);
-    g_assert_cmpint(g_hash_table_size(connections), ==, 2);
-    g_assert_cmpstr(hostname, ==, NULL);
+    for (i = 0; i < G_N_ELEMENTS(ARGV); i++) {
+        connections = nmi_cmdline_reader_parse(TEST_INITRD_DIR "/sysfs", ARGV[i], &hostname);
+        g_assert(connections);
+        g_assert_cmpint(g_hash_table_size(connections), ==, 2);
+        g_assert_cmpstr(hostname, ==, NULL);
 
-    connection = g_hash_table_lookup(connections, "eth0");
-    g_assert(connection);
-    nmtst_assert_connection_verifies_without_normalization(connection);
-    g_assert_cmpstr(nm_connection_get_id(connection), ==, "eth0");
+        connection = g_hash_table_lookup(connections, "eth0");
+        g_assert(connection);
+        nmtst_assert_connection_verifies_without_normalization(connection);
+        g_assert_cmpstr(nm_connection_get_id(connection), ==, "eth0");
 
-    s_wired = nm_connection_get_setting_wired(connection);
-    g_assert(!nm_setting_wired_get_mac_address(s_wired));
-    g_assert(s_wired);
+        s_wired = nm_connection_get_setting_wired(connection);
+        g_assert(!nm_setting_wired_get_mac_address(s_wired));
+        g_assert(s_wired);
 
-    s_ip4 = nm_connection_get_setting_ip4_config(connection);
-    g_assert(s_ip4);
-    g_assert_cmpstr(nm_setting_ip_config_get_method(s_ip4), ==, NM_SETTING_IP4_CONFIG_METHOD_AUTO);
-    g_assert(!nm_setting_ip_config_get_ignore_auto_dns(s_ip4));
-    g_assert(!nm_setting_ip_config_get_may_fail(s_ip4));
+        s_ip4 = nm_connection_get_setting_ip4_config(connection);
+        g_assert(s_ip4);
+        g_assert_cmpstr(nm_setting_ip_config_get_method(s_ip4),
+                        ==,
+                        NM_SETTING_IP4_CONFIG_METHOD_AUTO);
+        g_assert(!nm_setting_ip_config_get_ignore_auto_dns(s_ip4));
+        g_assert(!nm_setting_ip_config_get_may_fail(s_ip4));
 
-    s_ip6 = nm_connection_get_setting_ip6_config(connection);
-    g_assert(s_ip6);
-    g_assert_cmpstr(nm_setting_ip_config_get_method(s_ip6), ==, NM_SETTING_IP6_CONFIG_METHOD_AUTO);
-    g_assert(!nm_setting_ip_config_get_ignore_auto_dns(s_ip6));
+        s_ip6 = nm_connection_get_setting_ip6_config(connection);
+        g_assert(s_ip6);
+        g_assert_cmpstr(nm_setting_ip_config_get_method(s_ip6),
+                        ==,
+                        NM_SETTING_IP6_CONFIG_METHOD_AUTO);
+        g_assert(!nm_setting_ip_config_get_ignore_auto_dns(s_ip6));
 
-    connection = g_hash_table_lookup(connections, "bootif_connection");
-    g_assert(connection);
-    nmtst_assert_connection_verifies_without_normalization(connection);
-    g_assert_cmpstr(nm_connection_get_id(connection), ==, "BOOTIF Connection");
+        connection = g_hash_table_lookup(connections, "bootif_connection");
+        g_assert(connection);
+        nmtst_assert_connection_verifies_without_normalization(connection);
+        g_assert_cmpstr(nm_connection_get_id(connection), ==, "BOOTIF Connection");
 
-    s_wired = nm_connection_get_setting_wired(connection);
-    g_assert_cmpstr(nm_setting_wired_get_mac_address(s_wired), ==, "00:53:AB:CD:02:03");
-    g_assert(s_wired);
+        s_wired = nm_connection_get_setting_wired(connection);
+        g_assert_cmpstr(nm_setting_wired_get_mac_address(s_wired), ==, "00:53:AB:CD:02:03");
+        g_assert(s_wired);
 
-    s_ip4 = nm_connection_get_setting_ip4_config(connection);
-    g_assert(s_ip4);
-    g_assert_cmpstr(nm_setting_ip_config_get_method(s_ip4), ==, NM_SETTING_IP4_CONFIG_METHOD_AUTO);
-    g_assert(!nm_setting_ip_config_get_ignore_auto_dns(s_ip4));
-    g_assert(nm_setting_ip_config_get_may_fail(s_ip4));
+        s_ip4 = nm_connection_get_setting_ip4_config(connection);
+        g_assert(s_ip4);
+        g_assert_cmpstr(nm_setting_ip_config_get_method(s_ip4),
+                        ==,
+                        NM_SETTING_IP4_CONFIG_METHOD_AUTO);
+        g_assert(!nm_setting_ip_config_get_ignore_auto_dns(s_ip4));
+        g_assert(nm_setting_ip_config_get_may_fail(s_ip4));
 
-    s_ip6 = nm_connection_get_setting_ip6_config(connection);
-    g_assert(s_ip6);
-    g_assert_cmpstr(nm_setting_ip_config_get_method(s_ip6), ==, NM_SETTING_IP6_CONFIG_METHOD_AUTO);
-    g_assert(!nm_setting_ip_config_get_ignore_auto_dns(s_ip6));
-    g_assert(nm_setting_ip_config_get_may_fail(s_ip6));
+        s_ip6 = nm_connection_get_setting_ip6_config(connection);
+        g_assert(s_ip6);
+        g_assert_cmpstr(nm_setting_ip_config_get_method(s_ip6),
+                        ==,
+                        NM_SETTING_IP6_CONFIG_METHOD_AUTO);
+        g_assert(!nm_setting_ip_config_get_ignore_auto_dns(s_ip6));
+        g_assert(nm_setting_ip_config_get_may_fail(s_ip6));
+    }
 }
 
 /* Check that nameservers are assigned to all existing