settings: change filename for per-connection metadata (previously UUID nm-loaded symlinks)

We may want to store meta-data for a profile to disk. The immediate
need are "tombstones": markers that the particular UUID is shadowed
and the profile does not exist (despite being in read-only location).

Change the filename of these symlinks from

  ".loaded-${UUID}.nmconnection"

to

  "${UUID}.nmmeta"

The leading dot is not desirable as tools tend to hide such files.
Use a different scheme for the filename that does not have the leading dot.
Note that nm_keyfile_utils_ignore_filename() would also ignore ".nmmeta"
as not a valid keyfile. This is just what we want, and influences the
choice of this file suffix.

Also, "nmmeta" is a better name, because this name alludes that there is
a wider use for the file: namely to have addtional per-profile metadata.
That is regardless that the upcoming first use will be only to store symlinks
to "/dev/null" to indicate the tombstones.

Note that per-profile metadata is not new. Currently we write the files

  /var/lib/NetworkManager/{seen-bssids,timestamps}

that have a similar purpose. Maybe the content from these files could one
day be migrated to the ".nmmeta" file. The naming scheme would make it
suitable.

5 files changed, 68 insertions, 54 deletions

diff --git a/libnm-core/nm-keyfile-internal.h b/libnm-core/nm-keyfile-internal.h
index 941fe0a18b..47838bb639 100644
--- a/libnm-core/nm-keyfile-internal.h
+++ b/libnm-core/nm-keyfile-internal.h
@@ -176,9 +176,9 @@ gboolean _nm_keyfile_has_values (GKeyFile *keyfile);
 
 #define NM_KEYFILE_PATH_SUFFIX_NMCONNECTION      ".nmconnection"
 
-#define NM_KEYFILE_PATH_PREFIX_NMLOADED          ".loaded-"
+#define NM_KEYFILE_PATH_SUFFIX_NMMETA            ".nmmeta"
 
-#define NM_KEYFILE_PATH_NMLOADED_NULL            "/dev/null"
+#define NM_KEYFILE_PATH_NMMETA_SYMLINK_NULL      "/dev/null"
 
 gboolean nm_keyfile_utils_ignore_filename (const char *filename, gboolean require_extension);
 
diff --git a/libnm-core/nm-keyfile.c b/libnm-core/nm-keyfile.c
index 8add4bfccf..1d3f24cfd6 100644
--- a/libnm-core/nm-keyfile.c
+++ b/libnm-core/nm-keyfile.c
@@ -3981,7 +3981,7 @@ nm_keyfile_utils_ignore_filename (const char *filename, gboolean require_extensi
 
 	if (require_extension) {
 		if (   l <= NM_STRLEN (NM_KEYFILE_PATH_SUFFIX_NMCONNECTION)
-		    || !g_str_has_suffix (base, NM_KEYFILE_PATH_SUFFIX_NMCONNECTION))
+		    || !NM_STR_HAS_SUFFIX (base, NM_KEYFILE_PATH_SUFFIX_NMCONNECTION))
 			return TRUE;
 		return FALSE;
 	}
@@ -3990,7 +3990,10 @@ nm_keyfile_utils_ignore_filename (const char *filename, gboolean require_extensi
 	if (base[l - 1] == '~')
 		return TRUE;
 
-	/* Ignore temporary files */
+	/* Ignore temporary files
+	 *
+	 * This check is also important to ignore .nmload files (see
+	 * %NM_KEYFILE_PATH_SUFFIX_NMMETA). */
 	if (check_mkstemp_suffix (base))
 		return TRUE;
 
diff --git a/src/settings/plugins/keyfile/nms-keyfile-utils.c b/src/settings/plugins/keyfile/nms-keyfile-utils.c
index 50e00263f7..f474181388 100644
--- a/src/settings/plugins/keyfile/nms-keyfile-utils.c
+++ b/src/settings/plugins/keyfile/nms-keyfile-utils.c
@@ -33,30 +33,71 @@
 
 /*****************************************************************************/
 
+const char *
+nms_keyfile_loaded_uuid_is_filename (const char *filename,
+                                     guint *out_uuid_len)
+{
+	const char *uuid;
+	const char *s;
+	gsize len;
+
+	s = strrchr (filename, '/');
+	if (s)
+		filename = &s[1];
+
+	len = strlen (filename);
+	if (   len <= NM_STRLEN (NM_KEYFILE_PATH_SUFFIX_NMMETA)
+	    || memcmp (&filename[len - NM_STRLEN (NM_KEYFILE_PATH_SUFFIX_NMMETA)],
+	               NM_KEYFILE_PATH_SUFFIX_NMMETA,
+	               NM_STRLEN (NM_KEYFILE_PATH_SUFFIX_NMMETA)) != 0) {
+		/* the filename does not have the right suffix. */
+		return NULL;
+	}
+
+	len -= NM_STRLEN (NM_KEYFILE_PATH_SUFFIX_NMMETA);
+
+	if (!NM_IN_SET (len, 36, 40)) {
+		/* the remaining part of the filename has not the right length to
+		 * contain a UUID (according to nm_utils_is_uuid()). */
+		return NULL;
+	}
+
+	uuid = nm_strndup_a (100, filename, len, NULL);
+	if (!nm_utils_is_uuid (uuid))
+		return NULL;
+
+	NM_SET_OUT (out_uuid_len, len);
+	return filename;
+}
+
 char *
 nms_keyfile_loaded_uuid_filename (const char *dirname,
                                   const char *uuid,
                                   gboolean temporary)
 {
 	char filename[250];
+	char *s;
 
 	nm_assert (dirname && dirname[0] == '/');
-	nm_assert (uuid && nm_utils_is_uuid (uuid) && !strchr (uuid, '/'));
+	nm_assert (   nm_utils_is_uuid (uuid)
+	           && !strchr (uuid, '/'));
 
 	if (g_snprintf (filename,
 	                sizeof (filename),
-	                "%s%s%s%s",
-	                NM_KEYFILE_PATH_PREFIX_NMLOADED,
+	                "%s%s%s",
 	                uuid,
-	                NM_KEYFILE_PATH_SUFFIX_NMCONNECTION,
+	                NM_KEYFILE_PATH_SUFFIX_NMMETA,
 	                temporary ? "~" : "") >= sizeof (filename)) {
-		/* valid uuids are limited in length. The buffer should always be large
-		 * enough. */
+		/* valid uuids are limited in length (nm_utils_is_uuid). The buffer should always
+		 * be large enough. */
 		nm_assert_not_reached ();
-		return NULL;
 	}
 
-	return g_build_filename (dirname, filename, NULL);
+	s = g_build_filename (dirname, filename, NULL);
+
+	nm_assert (nm_keyfile_utils_ignore_filename (s, FALSE));
+
+	return s;
 }
 
 gboolean
@@ -68,48 +109,15 @@ nms_keyfile_loaded_uuid_read (const char *dirname,
                               struct stat *out_st)
 {
 	const char *uuid;
-	const char *tmp;
-	gsize len;
+	guint uuid_len;
 	gs_free char *full_filename = NULL;
 	gs_free char *ln = NULL;
 
 	nm_assert (dirname && dirname[0] == '/');
 	nm_assert (filename && filename[0] && !strchr (filename, '/'));
 
-	if (filename[0] != '.') {
-		/* the hidden-uuid filename must start with '.'. That is,
-		 * so that it does not conflict with regular keyfiles according
-		 * to nm_keyfile_utils_ignore_filename(). */
-		return FALSE;
-	}
-
-	len = strlen (filename);
-	if (   len <= NM_STRLEN (NM_KEYFILE_PATH_PREFIX_NMLOADED)
-	    || memcmp (filename, NM_KEYFILE_PATH_PREFIX_NMLOADED, NM_STRLEN (NM_KEYFILE_PATH_PREFIX_NMLOADED)) != 0) {
-		/* the filename does not have the right prefix. */
-		return FALSE;
-	}
-
-	tmp = &filename[NM_STRLEN (NM_KEYFILE_PATH_PREFIX_NMLOADED)];
-	len -= NM_STRLEN (NM_KEYFILE_PATH_PREFIX_NMLOADED);
-
-	if (   len <= NM_STRLEN (NM_KEYFILE_PATH_SUFFIX_NMCONNECTION)
-	    || memcmp (&tmp[len - NM_STRLEN (NM_KEYFILE_PATH_SUFFIX_NMCONNECTION)],
-	               NM_KEYFILE_PATH_SUFFIX_NMCONNECTION,
-	               NM_STRLEN (NM_KEYFILE_PATH_SUFFIX_NMCONNECTION)) != 0) {
-		/* the file does not have the right suffix. */
-		return FALSE;
-	}
-	len -= NM_STRLEN (NM_KEYFILE_PATH_SUFFIX_NMCONNECTION);
-
-	if (!NM_IN_SET (len, 36, 40)) {
-		/* the remaining part of the filename has not the right length to
-		 * contain a UUID (according to nm_utils_is_uuid()). */
-		return FALSE;
-	}
-
-	uuid = nm_strndup_a (100, tmp, len, NULL);
-	if (!nm_utils_is_uuid (uuid))
+	uuid = nms_keyfile_loaded_uuid_is_filename (filename, &uuid_len);
+	if (!uuid)
 		return FALSE;
 
 	full_filename = g_build_filename (dirname, filename, NULL);
@@ -124,7 +132,7 @@ nms_keyfile_loaded_uuid_read (const char *dirname,
 	if (!ln)
 		return FALSE;
 
-	NM_SET_OUT (out_uuid, g_strdup (uuid));
+	NM_SET_OUT (out_uuid, g_strndup (uuid, uuid_len));
 	NM_SET_OUT (out_full_filename, g_steal_pointer (&full_filename));
 	NM_SET_OUT (out_loaded_path, g_steal_pointer (&ln));
 	return TRUE;
@@ -169,7 +177,8 @@ nms_keyfile_loaded_uuid_write (const char *dirname,
 	gs_free char *full_filename = NULL;
 
 	nm_assert (dirname && dirname[0] == '/');
-	nm_assert (uuid && nm_utils_is_uuid (uuid) && !strchr (uuid, '/'));
+	nm_assert (   nm_utils_is_uuid (uuid)
+	           && !strchr (uuid, '/'));
 	nm_assert (!loaded_path || loaded_path[0] == '/');
 
 	full_filename_tmp = nms_keyfile_loaded_uuid_filename (dirname, uuid, TRUE);
diff --git a/src/settings/plugins/keyfile/nms-keyfile-utils.h b/src/settings/plugins/keyfile/nms-keyfile-utils.h
index 8a31232d08..43748cbdbd 100644
--- a/src/settings/plugins/keyfile/nms-keyfile-utils.h
+++ b/src/settings/plugins/keyfile/nms-keyfile-utils.h
@@ -37,6 +37,9 @@ const char *nms_keyfile_utils_get_path (void);
 
 /*****************************************************************************/
 
+const char *nms_keyfile_loaded_uuid_is_filename (const char *filename,
+                                                 guint *out_uuid_len);
+
 char *nms_keyfile_loaded_uuid_filename (const char *dirname,
                                         const char *uuid,
                                         gboolean temporary);
diff --git a/src/settings/plugins/keyfile/tests/test-keyfile-settings.c b/src/settings/plugins/keyfile/tests/test-keyfile-settings.c
index 4d02c58b7f..0604560599 100644
--- a/src/settings/plugins/keyfile/tests/test-keyfile-settings.c
+++ b/src/settings/plugins/keyfile/tests/test-keyfile-settings.c
@@ -2578,14 +2578,13 @@ static void
 test_loaded_uuid (void)
 {
 	const char *uuid = "3c03fd17-ddc3-4100-a954-88b6fafff959";
-	gs_free char *filename = g_strdup_printf ("%s%s%s",
-	                                          NM_KEYFILE_PATH_PREFIX_NMLOADED,
+	gs_free char *filename = g_strdup_printf ("%s%s",
 	                                          uuid,
-	                                          NM_KEYFILE_PATH_SUFFIX_NMCONNECTION);
+	                                          NM_KEYFILE_PATH_SUFFIX_NMMETA);
 	gs_free char *full_filename = g_strdup_printf ("%s/%s",
 	                                               TEST_SCRATCH_DIR,
 	                                               filename);
-	const char *loaded_path0 = NM_KEYFILE_PATH_NMLOADED_NULL;
+	const char *loaded_path0 = NM_KEYFILE_PATH_NMMETA_SYMLINK_NULL;
 	const char *loaded_path1 = "/some/where/but/not/scratch/dir";
 	const char *filename2 = "foo1";
 	gs_free char *loaded_path2 = g_strdup_printf ("%s/%s",