batman-adv: move bat_algo functions into a separate file

The bat_algo functionality in main.c is mostly unrelated to the rest of the
content. It still takes up a large portion of this source file (~15%, 103
lines). Moving it to a separate file makes it better visible as a main
component of the batman-adv implementation and hides it less in the other
helper functions in main.c.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
diff --git a/net/batman-adv/bat_algo.c b/net/batman-adv/bat_algo.c
new file mode 100644
index 0000000..610d4de
--- /dev/null
+++ b/net/batman-adv/bat_algo.c
@@ -0,0 +1,140 @@
+/* Copyright (C) 2007-2016  B.A.T.M.A.N. contributors:
+ *
+ * Marek Lindner, Simon Wunderlich
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "main.h"
+
+#include <linux/errno.h>
+#include <linux/list.h>
+#include <linux/moduleparam.h>
+#include <linux/printk.h>
+#include <linux/seq_file.h>
+#include <linux/stddef.h>
+#include <linux/string.h>
+
+#include "bat_algo.h"
+
+char batadv_routing_algo[20] = "BATMAN_IV";
+static struct hlist_head batadv_algo_list;
+
+/**
+ * batadv_algo_init - Initialize batman-adv algorithm management data structures
+ */
+void batadv_algo_init(void)
+{
+	INIT_HLIST_HEAD(&batadv_algo_list);
+}
+
+static struct batadv_algo_ops *batadv_algo_get(char *name)
+{
+	struct batadv_algo_ops *bat_algo_ops = NULL, *bat_algo_ops_tmp;
+
+	hlist_for_each_entry(bat_algo_ops_tmp, &batadv_algo_list, list) {
+		if (strcmp(bat_algo_ops_tmp->name, name) != 0)
+			continue;
+
+		bat_algo_ops = bat_algo_ops_tmp;
+		break;
+	}
+
+	return bat_algo_ops;
+}
+
+int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops)
+{
+	struct batadv_algo_ops *bat_algo_ops_tmp;
+
+	bat_algo_ops_tmp = batadv_algo_get(bat_algo_ops->name);
+	if (bat_algo_ops_tmp) {
+		pr_info("Trying to register already registered routing algorithm: %s\n",
+			bat_algo_ops->name);
+		return -EEXIST;
+	}
+
+	/* all algorithms must implement all ops (for now) */
+	if (!bat_algo_ops->bat_iface_enable ||
+	    !bat_algo_ops->bat_iface_disable ||
+	    !bat_algo_ops->bat_iface_update_mac ||
+	    !bat_algo_ops->bat_primary_iface_set ||
+	    !bat_algo_ops->bat_neigh_cmp ||
+	    !bat_algo_ops->bat_neigh_is_similar_or_better) {
+		pr_info("Routing algo '%s' does not implement required ops\n",
+			bat_algo_ops->name);
+		return -EINVAL;
+	}
+
+	INIT_HLIST_NODE(&bat_algo_ops->list);
+	hlist_add_head(&bat_algo_ops->list, &batadv_algo_list);
+
+	return 0;
+}
+
+int batadv_algo_select(struct batadv_priv *bat_priv, char *name)
+{
+	struct batadv_algo_ops *bat_algo_ops;
+
+	bat_algo_ops = batadv_algo_get(name);
+	if (!bat_algo_ops)
+		return -EINVAL;
+
+	bat_priv->bat_algo_ops = bat_algo_ops;
+
+	return 0;
+}
+
+int batadv_algo_seq_print_text(struct seq_file *seq, void *offset)
+{
+	struct batadv_algo_ops *bat_algo_ops;
+
+	seq_puts(seq, "Available routing algorithms:\n");
+
+	hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
+		seq_printf(seq, " * %s\n", bat_algo_ops->name);
+	}
+
+	return 0;
+}
+
+static int batadv_param_set_ra(const char *val, const struct kernel_param *kp)
+{
+	struct batadv_algo_ops *bat_algo_ops;
+	char *algo_name = (char *)val;
+	size_t name_len = strlen(algo_name);
+
+	if (name_len > 0 && algo_name[name_len - 1] == '\n')
+		algo_name[name_len - 1] = '\0';
+
+	bat_algo_ops = batadv_algo_get(algo_name);
+	if (!bat_algo_ops) {
+		pr_err("Routing algorithm '%s' is not supported\n", algo_name);
+		return -EINVAL;
+	}
+
+	return param_set_copystring(algo_name, kp);
+}
+
+static const struct kernel_param_ops batadv_param_ops_ra = {
+	.set = batadv_param_set_ra,
+	.get = param_get_string,
+};
+
+static struct kparam_string batadv_param_string_ra = {
+	.maxlen = sizeof(batadv_routing_algo),
+	.string = batadv_routing_algo,
+};
+
+module_param_cb(routing_algo, &batadv_param_ops_ra, &batadv_param_string_ra,
+		0644);