/*
 * lib/route/class.c            Queueing Classes
 *
 *	This library is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU Lesser General Public
 *	License as published by the Free Software Foundation version 2.1
 *	of the License.
 *
 * Copyright (c) 2003-2010 Thomas Graf <tgraf@suug.ch>
 */

/**
 * @ingroup tc
 * @defgroup class Queueing Classes
 * @{
 */

#include <netlink-local.h>
#include <netlink-tc.h>
#include <netlink/netlink.h>
#include <netlink/route/tc-api.h>
#include <netlink/route/class.h>
#include <netlink/route/qdisc.h>
#include <netlink/route/classifier.h>
#include <netlink/utils.h>

static struct nl_cache_ops rtnl_class_ops;
static struct nl_object_ops class_obj_ops;

static void class_dump_details(struct rtnl_tc *tc, struct nl_dump_params *p)
{
	struct rtnl_class *class = (struct rtnl_class *) tc;
	char buf[32];

	if (class->c_info)
		nl_dump(p, "child-qdisc %s ",
			rtnl_tc_handle2str(class->c_info, buf, sizeof(buf)));
}


static int class_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who,
			    struct nlmsghdr *nlh, struct nl_parser_param *pp)
{
	struct rtnl_class *class;
	int err;

	if (!(class = rtnl_class_alloc()))
		return -NLE_NOMEM;

	if ((err = rtnl_tc_msg_parse(nlh, TC_CAST(class))) < 0)
		goto errout;

	err = pp->pp_cb(OBJ_CAST(class), pp);
errout:
	rtnl_class_put(class);

	return err;
}

static int class_request_update(struct nl_cache *cache, struct nl_sock *sk)
{
	struct tcmsg tchdr = {
		.tcm_family = AF_UNSPEC,
		.tcm_ifindex = cache->c_iarg1,
	};

	return nl_send_simple(sk, RTM_GETTCLASS, NLM_F_DUMP, &tchdr,
			      sizeof(tchdr));
}

/**
 * @name Addition/Modification
 * @{
 */

static int class_build(struct rtnl_class *class, int type, int flags,
		       struct nl_msg **result)
{
	return rtnl_tc_msg_build(TC_CAST(class), type, flags, result);
}

/**
 * Build a netlink message to add a new class
 * @arg class		class to add 
 * @arg flags		additional netlink message flags
 * @arg result		Pointer to store resulting message.
 *
 * Builds a new netlink message requesting an addition of a class.
 * The netlink message header isn't fully equipped with all relevant
 * fields and must be sent out via nl_send_auto_complete() or
 * supplemented as needed. 
 *
 * Common message flags
 *   - NLM_F_REPLACE - replace possibly existing classes
 *
 * @return 0 on success or a negative error code.
 */
int rtnl_class_build_add_request(struct rtnl_class *class, int flags,
				 struct nl_msg **result)
{
	return class_build(class, RTM_NEWTCLASS, NLM_F_CREATE | flags, result);
}

/**
 * Add a new class
 * @arg sk		Netlink socket.
 * @arg class		class to delete
 * @arg flags		additional netlink message flags
 *
 * Builds a netlink message by calling rtnl_qdisc_build_add_request(),
 * sends the request to the kernel and waits for the next ACK to be
 * received and thus blocks until the request has been processed.
 *
 * Common message flags
 *   - NLM_F_REPLACE - replace possibly existing classes
 *
 * @return 0 on success or a negative error code
 */
int rtnl_class_add(struct nl_sock *sk, struct rtnl_class *class, int flags)
{
	struct nl_msg *msg;
	int err;

	if ((err = rtnl_class_build_add_request(class, flags, &msg)) < 0)
		return err;

	err = nl_send_auto_complete(sk, msg);
	nlmsg_free(msg);
	if (err < 0)
		return err;

	return wait_for_ack(sk);
}

int rtnl_class_build_delete_request(struct rtnl_class *class,
									struct nl_msg **result)
{
	struct nl_msg *msg;
	struct tcmsg tchdr;
	int required = TCA_ATTR_IFINDEX | TCA_ATTR_PARENT;

	if ((class->ce_mask & required) != required)
		BUG();

	msg = nlmsg_alloc_simple(RTM_DELTCLASS, 0);
	if (!msg)
		return -NLE_NOMEM;

	tchdr.tcm_family = AF_UNSPEC;
	tchdr.tcm_handle = class->c_handle;
	tchdr.tcm_parent = class->c_parent;
	tchdr.tcm_ifindex = class->c_ifindex;
	if (nlmsg_append(msg, &tchdr, sizeof(tchdr), NLMSG_ALIGNTO) < 0) {
		nlmsg_free(msg);
		return -NLE_MSGSIZE;
	}

	*result = msg;
	return 0;
}

/**
 * Delete a class
 * @arg sk		Netlink socket.
 * @arg class		class to delete
 *
 * Builds a netlink message by calling rtnl_class_build_delete_request(),
 * sends the request to the kernel and waits for the ACK to be
 * received and thus blocks until the request has been processed.
 *
 * @return 0 on success or a negative error code
 */
int rtnl_class_delete(struct nl_sock *sk, struct rtnl_class *class)
{
	struct nl_msg *msg;
	int err;

	if ((err = rtnl_class_build_delete_request(class, &msg)) < 0)
		return err;

	err = nl_send_auto_complete(sk, msg);
	nlmsg_free(msg);
	if (err < 0)
		return err;

	return wait_for_ack(sk);
}

/** @} */

/**
 * @name Allocation/Freeing
 * @{
 */

struct rtnl_class *rtnl_class_alloc(void)
{
	struct rtnl_tc *tc;

	tc = TC_CAST(nl_object_alloc(&class_obj_ops));
	if (tc)
		tc->tc_type = RTNL_TC_TYPE_CLASS;

	return (struct rtnl_class *) tc;
}

void rtnl_class_put(struct rtnl_class *class)
{
	nl_object_put((struct nl_object *) class);
}

/** @} */

/**
 * @name Leaf Qdisc
 * @{
 */

/**
 * Lookup the leaf qdisc of a class
 * @arg class		the parent class
 * @arg cache		a qdisc cache including at laest all qdiscs of the
 *                      interface the specified class is attached to
 * @return The qdisc from the cache or NULL if the class has no leaf qdisc
 */
struct rtnl_qdisc *rtnl_class_leaf_qdisc(struct rtnl_class *class,
					 struct nl_cache *cache)
{
	struct rtnl_qdisc *leaf;

	if (!class->c_info)
		return NULL;

	leaf = rtnl_qdisc_get_by_parent(cache, class->c_ifindex,
					class->c_handle);
	if (!leaf || leaf->q_handle != class->c_info)
		return NULL;

	return leaf;
}

/** @} */


/**
 * @name Iterators
 * @{
 */

/**
 * Call a callback for each child of a class
 * @arg class		the parent class
 * @arg cache		a class cache including all classes of the interface
 *                      the specified class is attached to
 * @arg cb              callback function
 * @arg arg             argument to be passed to callback function
 */
void rtnl_class_foreach_child(struct rtnl_class *class, struct nl_cache *cache,
			      void (*cb)(struct nl_object *, void *), void *arg)
{
	struct rtnl_class *filter;
	
	filter = rtnl_class_alloc();
	if (!filter)
		return;

	rtnl_tc_set_parent(TC_CAST(filter), class->c_handle);
	rtnl_tc_set_ifindex(TC_CAST(filter), class->c_ifindex);
	rtnl_tc_set_kind(TC_CAST(filter), class->c_kind);

	nl_cache_foreach_filter(cache, OBJ_CAST(filter), cb, arg);
	rtnl_class_put(filter);
}

/**
 * Call a callback for each classifier attached to the class
 * @arg class		the parent class
 * @arg cache		a filter cache including at least all the filters
 *                      attached to the specified class
 * @arg cb              callback function
 * @arg arg             argument to be passed to callback function
 */
void rtnl_class_foreach_cls(struct rtnl_class *class, struct nl_cache *cache,
			    void (*cb)(struct nl_object *, void *), void *arg)
{
	struct rtnl_cls *filter;

	filter = rtnl_cls_alloc();
	if (!filter)
		return;

	rtnl_tc_set_ifindex((struct rtnl_tc *) filter, class->c_ifindex);
	rtnl_tc_set_parent((struct rtnl_tc *) filter, class->c_parent);

	nl_cache_foreach_filter(cache, (struct nl_object *) filter, cb, arg);
	rtnl_cls_put(filter);
}

/** @} */


/**
 * @name Cache Management
 * @{
 */

/**
 * Build a class cache including all classes attached to the specified interface
 * @arg sk		Netlink socket.
 * @arg ifindex		interface index of the link the classes are
 *                      attached to.
 * @arg result		Result pointer
 *
 * Allocates a new cache, initializes it properly and updates it to
 * include all classes attached to the specified interface.
 *
 * @return 0 on success or a negative error code.
 */
int rtnl_class_alloc_cache(struct nl_sock *sk, int ifindex,
			   struct nl_cache **result)
{
	struct nl_cache * cache;
	int err;
	
	cache = nl_cache_alloc(&rtnl_class_ops);
	if (!cache)
		return -NLE_NOMEM;

	cache->c_iarg1 = ifindex;
	
	if (sk && (err = nl_cache_refill(sk, cache)) < 0) {
		nl_cache_free(cache);
		return err;
	}

	*result = cache;
	return 0;
}

/**
 * Look up class by its handle in the provided cache
 * @arg cache		class cache
 * @arg ifindex		interface the class is attached to
 * @arg handle		class handle
 * @return pointer to class inside the cache or NULL if no match was found.
 */
struct rtnl_class *rtnl_class_get(struct nl_cache *cache, int ifindex,
								  uint32_t handle)
{
	struct rtnl_class *class;
	
	if (cache->c_ops != &rtnl_class_ops)
		return NULL;

	nl_list_for_each_entry(class, &cache->c_items, ce_list) {
		if (class->c_handle == handle && class->c_ifindex == ifindex) {
			nl_object_get((struct nl_object *) class);
			return class;
		}
	}
	return NULL;
}

/** @} */

static struct rtnl_tc_type_ops class_ops = {
	.tt_type		= RTNL_TC_TYPE_CLASS,
	.tt_dump_prefix		= "class",
	.tt_dump = {
	    [NL_DUMP_DETAILS]	= class_dump_details,
	},
};

static struct nl_object_ops class_obj_ops = {
	.oo_name		= "route/class",
	.oo_size		= sizeof(struct rtnl_class),
	.oo_free_data         	= rtnl_tc_free_data,
	.oo_clone		= rtnl_tc_clone,
	.oo_dump = {
	    [NL_DUMP_LINE]	= rtnl_tc_dump_line,
	    [NL_DUMP_DETAILS]	= rtnl_tc_dump_details,
	    [NL_DUMP_STATS]	= rtnl_tc_dump_stats,
	},
	.oo_compare		= rtnl_tc_compare,
	.oo_id_attrs		= (TCA_ATTR_IFINDEX | TCA_ATTR_HANDLE),
};

static struct nl_cache_ops rtnl_class_ops = {
	.co_name		= "route/class",
	.co_hdrsize		= sizeof(struct tcmsg),
	.co_msgtypes		= {
					{ RTM_NEWTCLASS, NL_ACT_NEW, "new" },
					{ RTM_DELTCLASS, NL_ACT_DEL, "del" },
					{ RTM_GETTCLASS, NL_ACT_GET, "get" },
					END_OF_MSGTYPES_LIST,
				  },
	.co_protocol		= NETLINK_ROUTE,
	.co_request_update	= &class_request_update,
	.co_msg_parser		= &class_msg_parser,
	.co_obj_ops		= &class_obj_ops,
};

static void __init class_init(void)
{
	rtnl_tc_type_register(&class_ops);
	nl_cache_mngt_register(&rtnl_class_ops);
}

static void __exit class_exit(void)
{
	nl_cache_mngt_unregister(&rtnl_class_ops);
	rtnl_tc_type_unregister(&class_ops);
}

/** @} */