knownnetworks: Add known frequencies

Add functionality to read and parse the known frequencies
from permanent storage on start of the service. On service
shutdown, we sync the known frequencies back to the permanent
storage.

src/knownnetworks.c

@@ -2,7 +2,7 @@
  *
  *  Wireless daemon for Linux
  *
- *  Copyright (C) 2016  Intel Corporation. All rights reserved.
+ *  Copyright (C) 2016-2019  Intel Corporation. All rights reserved.
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public
@@ -420,6 +420,153 @@ static void known_networks_watch_destroy(void *user_data)
 	storage_dir_watch = NULL;
 }
 
+static struct l_queue *known_frequencies_from_string(char *freq_set_str)
+{
+	struct l_queue *known_frequencies;
+	struct known_frequency *known_freq;
+	uint16_t t;
+
+	if (!freq_set_str)
+		return NULL;
+
+	if (*freq_set_str == '\0')
+		return NULL;
+
+	known_frequencies = l_queue_new();
+
+	while (*freq_set_str != '\0') {
+		errno = 0;
+
+		t = strtoul(freq_set_str, &freq_set_str, 10);
+
+		if (unlikely(errno == ERANGE || !t || t > 6000))
+			goto error;
+
+		known_freq = l_new(struct known_frequency, 1);
+		known_freq->frequency = t;
+
+		l_queue_push_tail(known_frequencies, known_freq);
+	}
+
+	if (l_queue_isempty(known_frequencies))
+		goto error;
+
+	return known_frequencies;
+
+error:
+	l_queue_destroy(known_frequencies, l_free);
+
+	return NULL;
+}
+
+static void known_frequency_to_string(void *data, void *user_data)
+{
+	struct known_frequency *known_freq = data;
+	struct l_string *str = user_data;
+
+	l_string_append_printf(str, " %u", known_freq->frequency);
+}
+
+static char *known_frequencies_to_string(struct l_queue *known_frequencies)
+{
+	struct l_string *str;
+
+	str = l_string_new(100);
+
+	l_queue_foreach(known_frequencies, known_frequency_to_string, str);
+
+	return l_string_unwrap(str);
+}
+
+static void known_network_frequencies_load(void)
+{
+	char **network_names;
+	struct l_settings *known_freqs;
+	struct l_queue *known_frequencies;
+	uint32_t i;
+
+	known_freqs = storage_known_frequencies_load();
+	if (!known_freqs) {
+		l_debug("No known frequency file found.");
+		return;
+	}
+
+	network_names = l_settings_get_groups(known_freqs);
+	if (!network_names[0])
+		goto done;
+
+	for (i = 0; network_names[i]; i++) {
+		struct network_info *network_info;
+		enum security security;
+		const char *ssid;
+		char *freq_list;
+
+		ssid = storage_network_ssid_from_path(network_names[i],
+								&security);
+		if (!ssid)
+			continue;
+
+		freq_list = l_settings_get_string(known_freqs, network_names[i],
+									"list");
+		if (!freq_list)
+			continue;
+
+		network_info = known_networks_find(ssid, security);
+		if (!network_info)
+			goto next;
+
+		known_frequencies = known_frequencies_from_string(freq_list);
+		if (!known_frequencies)
+			goto next;
+
+		network_info->known_frequencies = known_frequencies;
+next:
+		l_free(freq_list);
+	}
+
+done:
+	l_strv_free(network_names);
+	l_settings_free(known_freqs);
+}
+
+static bool known_network_frequencies_to_settings(
+					const struct network_info *network_info,
+					void *user_data)
+{
+	struct l_settings *known_freqs = user_data;
+	char *freq_list_str;
+	char *network_path;
+
+	if (!network_info->known_frequencies)
+		return true;
+
+	freq_list_str = known_frequencies_to_string(
+					network_info->known_frequencies);
+
+	network_path = storage_get_network_file_path(network_info->type,
+							network_info->ssid);
+
+	l_settings_set_value(known_freqs, network_path, "list", freq_list_str);
+	l_free(network_path);
+	l_free(freq_list_str);
+
+	return true;
+}
+
+static void known_network_frequencies_sync(void)
+{
+	struct l_settings *known_freqs;
+
+	known_freqs = l_settings_new();
+
+	known_networks_foreach(known_network_frequencies_to_settings,
+								known_freqs);
+
+	storage_known_frequencies_sync(known_freqs);
+
+	l_settings_free(known_freqs);
+}
+
 bool known_networks_init(void)
 {
 	struct l_dbus *dbus = dbus_get_bus();
@@ -470,6 +617,8 @@ bool known_networks_init(void)
 
 	closedir(dir);
 
+	known_network_frequencies_load();
+
 	storage_dir_watch = l_dir_watch_new(DAEMON_STORAGEDIR,
 						known_networks_watch_cb, NULL,
 						known_networks_watch_destroy);
@@ -483,6 +632,8 @@ void known_networks_exit(void)
 
 	l_dir_watch_destroy(storage_dir_watch);
 
+	known_network_frequencies_sync();
+
 	l_queue_destroy(known_networks, network_info_free);
 	known_networks = NULL;