/* SPDX-FileCopyrightText: 2016-2019, Matthias Schiffer <mschiffer@universe-factory.net> */
/* SPDX-License-Identifier: BSD-2-Clause */

#include "respondd-common.h"

#include <batadv-genl.h>
#include <libgluonutil.h>

#include <json-c/json.h>

#include <netlink/netlink.h>
#include <netlink/genl/genl.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <net/if.h>


struct neigh_netlink_opts {
	struct json_object *interfaces;
	struct batadv_nlquery_opts query_opts;
};


static struct json_object * ifnames2addrs(struct json_object *interfaces) {
	struct json_object *ret = json_object_new_object();

	json_object_object_foreach(interfaces, ifname, interface) {
		char *ifaddr = gluonutil_get_interface_address(ifname);
		if (!ifaddr)
			continue;

		struct json_object *obj = json_object_new_object();
		json_object_object_add(obj, "neighbours", json_object_get(interface));
		json_object_object_add(ret, ifaddr, obj);

		free(ifaddr);
	}

	json_object_put(interfaces);

	return ret;
}

static const enum batadv_nl_attrs parse_orig_list_mandatory[] = {
	BATADV_ATTR_ORIG_ADDRESS,
	BATADV_ATTR_NEIGH_ADDRESS,
	BATADV_ATTR_TQ,
	BATADV_ATTR_HARD_IFINDEX,
	BATADV_ATTR_LAST_SEEN_MSECS,
};

static int parse_orig_list_netlink_cb(struct nl_msg *msg, void *arg)
{
	struct nlattr *attrs[BATADV_ATTR_MAX+1];
	struct nlmsghdr *nlh = nlmsg_hdr(msg);
	struct batadv_nlquery_opts *query_opts = arg;
	struct genlmsghdr *ghdr;
	uint8_t *orig;
	uint8_t *dest;
	uint8_t tq;
	uint32_t hardif;
	uint32_t lastseen;
	char ifname_buf[IF_NAMESIZE], *ifname;
	struct neigh_netlink_opts *opts;
	char mac1[18];

	opts = batadv_container_of(query_opts, struct neigh_netlink_opts,
			query_opts);

	if (!genlmsg_valid_hdr(nlh, 0))
		return NL_OK;

	ghdr = nlmsg_data(nlh);

	if (ghdr->cmd != BATADV_CMD_GET_ORIGINATORS)
		return NL_OK;

	if (nla_parse(attrs, BATADV_ATTR_MAX, genlmsg_attrdata(ghdr, 0),
				genlmsg_len(ghdr), batadv_genl_policy))
		return NL_OK;

	if (batadv_genl_missing_attrs(attrs, parse_orig_list_mandatory,
				BATADV_ARRAY_SIZE(parse_orig_list_mandatory)))
		return NL_OK;

	orig = nla_data(attrs[BATADV_ATTR_ORIG_ADDRESS]);
	dest = nla_data(attrs[BATADV_ATTR_NEIGH_ADDRESS]);
	tq = nla_get_u8(attrs[BATADV_ATTR_TQ]);
	hardif = nla_get_u32(attrs[BATADV_ATTR_HARD_IFINDEX]);
	lastseen = nla_get_u32(attrs[BATADV_ATTR_LAST_SEEN_MSECS]);

	if (memcmp(orig, dest, 6) != 0)
		return NL_OK;

	ifname = if_indextoname(hardif, ifname_buf);
	if (!ifname)
		return NL_OK;

	sprintf(mac1, "%02x:%02x:%02x:%02x:%02x:%02x",
		orig[0], orig[1], orig[2], orig[3], orig[4], orig[5]);

	struct json_object *obj = json_object_new_object();
	if (!obj)
		return NL_OK;

	struct json_object *interface;
	if (!json_object_object_get_ex(opts->interfaces, ifname, &interface)) {
		interface = json_object_new_object();
		json_object_object_add(opts->interfaces, ifname, interface);
	}

	json_object_object_add(obj, "tq", json_object_new_int(tq));
	json_object_object_add(obj, "lastseen", json_object_new_double(lastseen / 1000.));
	json_object_object_add(obj, "best", json_object_new_boolean(!!attrs[BATADV_ATTR_FLAG_BEST]));
	json_object_object_add(interface, mac1, obj);

	return NL_OK;
}

static struct json_object * get_batadv(void) {
	struct neigh_netlink_opts opts = {
		.query_opts = {
			.err = 0,
		},
	};
	int ret;

	opts.interfaces = json_object_new_object();
	if (!opts.interfaces)
		return NULL;

	ret = batadv_genl_query("bat0", BATADV_CMD_GET_ORIGINATORS,
				parse_orig_list_netlink_cb, NLM_F_DUMP,
				&opts.query_opts);
	if (ret < 0) {
		json_object_put(opts.interfaces);
		return NULL;
	}

	return ifnames2addrs(opts.interfaces);
}

struct json_object * respondd_provider_neighbours(void) {
	struct json_object *ret = json_object_new_object();

	struct json_object *batadv = get_batadv();
	if (batadv)
		json_object_object_add(ret, "batadv", batadv);

	return ret;
}