shared: add NMKeyFileDB API

It will be used for "/var/lib/NetworkManager/seen-bssids" and
"/var/lib/NetworkManager/timestamps" which currently is implemented
in NMSettingConnection.

2 files changed, 443 insertions, 0 deletions

diff --git a/shared/nm-glib-aux/nm-keyfile-aux.c b/shared/nm-glib-aux/nm-keyfile-aux.c
index a0d8186d8d..0257bcca7f 100644
--- a/shared/nm-glib-aux/nm-keyfile-aux.c
+++ b/shared/nm-glib-aux/nm-keyfile-aux.c
@@ -22,3 +22,392 @@
 
 #include "nm-keyfile-aux.h"
 
+#include <syslog.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include "nm-io-utils.h"
+
+/*****************************************************************************/
+
+struct _NMKeyFileDB {
+	NMKeyFileDBLogFcn log_fcn;
+	NMKeyFileDBGotDirtyFcn got_dirty_fcn;
+	gpointer user_data;
+	const char *group_name;
+	GKeyFile *kf;
+	guint ref_count;
+
+	bool is_started:1;
+	bool dirty:1;
+	bool destroyed:1;
+
+	char filename[];
+};
+
+#define _NMLOG(self, \
+               syslog_level, \
+               fmt, \
+               ...) \
+	G_STMT_START { \
+		NMKeyFileDB *_self = (self); \
+		\
+		nm_assert (_self); \
+		nm_assert (!_self->destroyed); \
+		\
+		if (_self->log_fcn) { \
+			_self->log_fcn (_self, \
+			                (syslog_level), \
+			                _self->user_data, \
+			                ""fmt"", \
+			                ##__VA_ARGS__); \
+		}; \
+	} G_STMT_END
+
+#define _LOGD(...) _NMLOG (self, LOG_DEBUG, __VA_ARGS__)
+
+static gboolean
+_IS_KEY_FILE_DB (NMKeyFileDB *self, gboolean require_is_started, gboolean allow_destroyed)
+{
+	if (self == NULL)
+		return FALSE;
+	if (self->ref_count <= 0) {
+		nm_assert_not_reached ();
+		return FALSE;
+	}
+	if (   require_is_started
+	    && !self->is_started)
+		return FALSE;
+	if (   !allow_destroyed
+	    && self->destroyed)
+		return FALSE;
+	return TRUE;
+}
+
+/*****************************************************************************/
+
+NMKeyFileDB *
+nm_key_file_db_new (const char *filename,
+                    const char *group_name,
+                    NMKeyFileDBLogFcn log_fcn,
+                    NMKeyFileDBGotDirtyFcn got_dirty_fcn,
+                    gpointer user_data)
+{
+	NMKeyFileDB *self;
+	gsize l_filename;
+	gsize l_group;
+
+	g_return_val_if_fail (filename && filename[0], NULL);
+	g_return_val_if_fail (group_name && group_name[0], NULL);
+
+	l_filename = strlen (filename);
+	l_group = strlen (group_name);
+
+	self = g_malloc0 (sizeof (NMKeyFileDB) + l_filename + 1 + l_group + 1);
+	self->ref_count = 1;
+	self->log_fcn = log_fcn;
+	self->got_dirty_fcn = got_dirty_fcn;
+	self->user_data = user_data;
+	self->kf = g_key_file_new ();
+	g_key_file_set_list_separator (self->kf, ',');
+	memcpy (self->filename, filename, l_filename + 1);
+	self->group_name = &self->filename[l_filename + 1];
+	memcpy ((char *) self->group_name, group_name, l_group + 1);
+
+	return self;
+}
+
+NMKeyFileDB *
+nm_key_file_db_ref (NMKeyFileDB *self)
+{
+	if (!self)
+		return NULL;
+
+	g_return_val_if_fail (_IS_KEY_FILE_DB (self, FALSE, TRUE), NULL);
+
+	nm_assert (self->ref_count <= G_MAXUINT);
+	self->ref_count++;
+	return self;
+}
+
+void
+nm_key_file_db_unref (NMKeyFileDB *self)
+{
+	if (!self)
+		return;
+
+	g_return_if_fail (_IS_KEY_FILE_DB (self, FALSE, TRUE));
+
+	if (--self->ref_count > 0)
+		return;
+
+	g_key_file_unref (self->kf);
+
+	g_free (self);
+}
+
+/* destroy() is like unref, but it also makes the instance unusable.
+ * All changes afterwards fail with an assertion.
+ *
+ * The point is that NMKeyFileDB is ref-counted in principle. But there
+ * is a primary owner who also provides the log_fcn().
+ *
+ * When the primary owner goes out of scope and gives up the reference, it does
+ * not want to receive any log notifications anymore.
+ *
+ * The way NMKeyFileDB is intended to be used is in a very strict context:
+ * NMSettings owns the NMKeyFileDB instance and receives logging notifications.
+ * It's also the last one to persist the data to disk. Afterwards, no other user
+ * is supposed to be around and do anything with NMKeyFileDB. But since NMKeyFileDB
+ * is ref-counted it's hard to ensure that this is truly honored. So we start
+ * asserting at that point.
+ */
+void
+nm_key_file_db_destroy (NMKeyFileDB *self)
+{
+	if (!self)
+		return;
+
+	g_return_if_fail (_IS_KEY_FILE_DB (self, FALSE, FALSE));
+	g_return_if_fail (!self->destroyed);
+
+	self->destroyed = TRUE;
+	nm_key_file_db_unref (self);
+}
+
+/*****************************************************************************/
+
+/* nm_key_file_db_start() is supposed to be called right away, after creating the
+ * instance.
+ *
+ * It's not done as separate step after nm_key_file_db_new(), because we want to log,
+ * and the log_fcn returns the self pointer (which we should not expose before
+ * nm_key_file_db_new() returns. */
+void
+nm_key_file_db_start (NMKeyFileDB *self)
+{
+	int r;
+	gs_free char *contents = NULL;
+	gsize contents_len;
+	gs_free_error GError *error = NULL;
+
+	g_return_if_fail (_IS_KEY_FILE_DB (self, FALSE, FALSE));
+	g_return_if_fail (!self->is_started);
+
+	self->is_started = TRUE;
+
+	r = nm_utils_file_get_contents (-1,
+	                                self->filename,
+	                                20*1024*1024,
+	                                NM_UTILS_FILE_GET_CONTENTS_FLAG_NONE,
+	                                &contents,
+	                                &contents_len,
+	                                &error);
+	if (r < 0) {
+		_LOGD ("failed to read \"%s\": %s", self->filename, error->message);
+		return;
+	}
+
+	if (!g_key_file_load_from_data (self->kf,
+	                                contents,
+	                                contents_len,
+	                                G_KEY_FILE_KEEP_COMMENTS,
+	                                &error)) {
+		_LOGD ("failed to load keyfile \"%s\": %s", self->filename, error->message);
+		return;
+	}
+
+	_LOGD ("loaded keyfile-db for \"%s\"", self->filename);
+}
+
+/*****************************************************************************/
+
+const char *
+nm_key_file_db_get_filename (NMKeyFileDB *self)
+{
+	g_return_val_if_fail (_IS_KEY_FILE_DB (self, FALSE, TRUE), NULL);
+
+	return self->filename;
+}
+
+gboolean
+nm_key_file_db_is_dirty (NMKeyFileDB *self)
+{
+	g_return_val_if_fail (_IS_KEY_FILE_DB (self, FALSE, TRUE), FALSE);
+
+	return self->dirty;
+}
+
+/*****************************************************************************/
+
+char *
+nm_key_file_db_get_value (NMKeyFileDB *self,
+                          const char *key)
+{
+	g_return_val_if_fail (_IS_KEY_FILE_DB (self, TRUE, TRUE), NULL);
+
+	return g_key_file_get_value (self->kf, self->group_name, key, NULL);
+}
+
+char **
+nm_key_file_db_get_string_list (NMKeyFileDB *self,
+                                const char *key,
+                                gsize *out_len)
+{
+	g_return_val_if_fail (_IS_KEY_FILE_DB (self, TRUE, TRUE), NULL);
+
+	return g_key_file_get_string_list (self->kf, self->group_name, key, out_len, NULL);
+}
+
+/*****************************************************************************/
+
+static void
+_got_dirty (NMKeyFileDB *self,
+            const char *key)
+{
+	nm_assert (_IS_KEY_FILE_DB (self, TRUE, FALSE));
+	nm_assert (!self->dirty);
+
+	_LOGD ("updated entry for %s.%s", self->group_name, key);
+
+	self->dirty = TRUE;
+	if (self->got_dirty_fcn)
+		self->got_dirty_fcn (self, self->user_data);
+}
+
+/*****************************************************************************/
+
+void
+nm_key_file_db_remove_key (NMKeyFileDB *self,
+                           const char *key)
+{
+	gboolean got_dirty = FALSE;
+
+	g_return_if_fail (_IS_KEY_FILE_DB (self, TRUE, FALSE));
+
+	if (!key)
+		return;
+
+	if (!self->dirty) {
+		gs_free_error GError *error = NULL;
+
+		g_key_file_has_key (self->kf, self->group_name, key, &error);
+		got_dirty = (error != NULL);
+	}
+	g_key_file_remove_key (self->kf, self->group_name, key, NULL);
+
+	if (got_dirty)
+		_got_dirty (self, key);
+}
+
+void
+nm_key_file_db_set_value (NMKeyFileDB *self,
+                          const char *key,
+                          const char *value)
+{
+	gs_free char *old_value = NULL;
+	gboolean got_dirty = FALSE;
+
+	g_return_if_fail (_IS_KEY_FILE_DB (self, TRUE, FALSE));
+	g_return_if_fail (key);
+
+	if (!value) {
+		nm_key_file_db_remove_key (self, key);
+		return;
+	}
+
+	if (!self->dirty) {
+		gs_free_error GError *error = NULL;
+
+		old_value = g_key_file_get_value (self->kf, self->group_name, key, &error);
+		if (error)
+			got_dirty = TRUE;
+	}
+
+	g_key_file_set_value (self->kf, self->group_name, key, value);
+
+	if (   !self->dirty
+	    && !got_dirty) {
+		gs_free_error GError *error = NULL;
+		gs_free char *new_value = NULL;
+
+		new_value = g_key_file_get_value (self->kf, self->group_name, key, &error);
+		if (   error
+		    || !new_value
+		    || !nm_streq0 (old_value, new_value))
+			got_dirty = TRUE;
+	}
+
+	if (got_dirty)
+		_got_dirty (self, key);
+}
+
+void
+nm_key_file_db_set_string_list (NMKeyFileDB *self,
+                                const char *key,
+                                const char *const*value,
+                                gssize len)
+{
+	gs_free char *old_value = NULL;
+	gboolean got_dirty = FALSE;;
+
+	g_return_if_fail (_IS_KEY_FILE_DB (self, TRUE, FALSE));
+	g_return_if_fail (key);
+
+	if (!value) {
+		nm_key_file_db_remove_key (self, key);
+		return;
+	}
+
+	if (!self->dirty) {
+		gs_free_error GError *error = NULL;
+
+		old_value = g_key_file_get_value (self->kf, self->group_name, key, &error);
+		if (error)
+			got_dirty = TRUE;
+	}
+
+	if (len < 0)
+		len = NM_PTRARRAY_LEN (value);
+
+	g_key_file_set_string_list (self->kf, self->group_name, key, value, len);
+
+	if (   !self->dirty
+	    && !got_dirty) {
+		gs_free_error GError *error = NULL;
+		gs_free char *new_value = NULL;
+
+		new_value = g_key_file_get_value (self->kf, self->group_name, key, &error);
+		if (   error
+		    || !new_value
+		    || !nm_streq0 (old_value, new_value))
+			got_dirty = TRUE;
+	}
+
+	if (got_dirty)
+		_got_dirty (self, key);
+}
+
+/*****************************************************************************/
+
+void
+nm_key_file_db_to_file (NMKeyFileDB *self,
+                        gboolean force)
+{
+	gs_free_error GError *error = NULL;
+
+	g_return_if_fail (_IS_KEY_FILE_DB (self, TRUE, FALSE));
+
+	if (   !force
+	    && !self->dirty)
+		return;
+
+	self->dirty = FALSE;
+
+	if (!g_key_file_save_to_file (self->kf,
+	                              self->filename,
+	                              &error)) {
+		_LOGD ("failure to write keyfile \"%s\": %s", self->filename, error->message);
+	} else
+		_LOGD ("write keyfile: \"%s\"", self->filename);
+}
diff --git a/shared/nm-glib-aux/nm-keyfile-aux.h b/shared/nm-glib-aux/nm-keyfile-aux.h
index f7ef866c92..8563f4d186 100644
--- a/shared/nm-glib-aux/nm-keyfile-aux.h
+++ b/shared/nm-glib-aux/nm-keyfile-aux.h
@@ -21,4 +21,58 @@
 #ifndef __NM_KEYFILE_AUX_H__
 #define __NM_KEYFILE_AUX_H__
 
+/*****************************************************************************/
+
+typedef struct _NMKeyFileDB NMKeyFileDB;
+
+typedef void (*NMKeyFileDBLogFcn) (NMKeyFileDB *self,
+                                   int syslog_level,
+                                   gpointer user_data,
+                                   const char *fmt,
+                                   ...) G_GNUC_PRINTF (4, 5);
+
+typedef void (*NMKeyFileDBGotDirtyFcn) (NMKeyFileDB *self,
+                                        gpointer user_data);
+
+NMKeyFileDB *nm_key_file_db_new (const char *filename,
+                                 const char *group,
+                                 NMKeyFileDBLogFcn log_fcn,
+                                 NMKeyFileDBGotDirtyFcn got_dirty_fcn,
+                                 gpointer user_data);
+
+void nm_key_file_db_start (NMKeyFileDB *self);
+
+NMKeyFileDB *nm_key_file_db_ref (NMKeyFileDB *self);
+void nm_key_file_db_unref (NMKeyFileDB *self);
+
+void nm_key_file_db_destroy (NMKeyFileDB *self);
+
+const char *nm_key_file_db_get_filename (NMKeyFileDB *self);
+
+gboolean nm_key_file_db_is_dirty (NMKeyFileDB *self);
+
+char *nm_key_file_db_get_value (NMKeyFileDB *self,
+                                const char *key);
+
+char **nm_key_file_db_get_string_list (NMKeyFileDB *self,
+                                       const char *key,
+                                       gsize *out_len);
+
+void nm_key_file_db_remove_key (NMKeyFileDB *self,
+                                const char *key);
+
+void nm_key_file_db_set_value (NMKeyFileDB *self,
+                               const char *key,
+                               const char *value);
+
+void nm_key_file_db_set_string_list (NMKeyFileDB *self,
+                                     const char *key,
+                                     const char *const*value,
+                                     gssize len);
+
+void nm_key_file_db_to_file (NMKeyFileDB *self,
+                             gboolean force);
+
+/*****************************************************************************/
+
 #endif /* __NM_KEYFILE_AUX_H__ */