class.c

/*
 * 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) 2003-2006 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.h>
#include <netlink/route/class.h>
#include <netlink/route/class-modules.h>
#include <netlink/route/qdisc.h>
#include <netlink/route/classifier.h>
#include <netlink/utils.h>
 
static struct nl_cache_ops rtnl_class_ops;
 
static int class_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who,
                            struct nlmsghdr *n, struct nl_parser_param *pp)
{
        int err;
        struct rtnl_class *class;
        struct rtnl_class_ops *cops;
 
        class = rtnl_class_alloc();
        if (!class) {
                err = nl_errno(ENOMEM);
                goto errout;
        }
        class->ce_msgtype = n->nlmsg_type;
 
        err = tca_msg_parser(n, (struct rtnl_tca *) class);
        if (err < 0)
                goto errout_free;
 
        cops = rtnl_class_lookup_ops(class);
        if (cops && cops->co_msg_parser) {
                err = cops->co_msg_parser(class);
                if (err < 0)
                        goto errout_free;
        }
 
        err = pp->pp_cb((struct nl_object *) class, pp);
        if (err < 0)
                goto errout_free;
 
        err = P_ACCEPT;
 
errout_free:
        rtnl_class_put(class);
errout:
        return err;
}
 
static int class_request_update(struct nl_cache *cache,
                                struct nl_handle *handle)
{
        struct tcmsg tchdr = {
                .tcm_family = AF_UNSPEC,
                .tcm_ifindex = cache->c_iarg1,
        };
 
        return nl_send_simple(handle, RTM_GETTCLASS, NLM_F_DUMP, &tchdr,
                              sizeof(tchdr));
}
 
/**
 * @name Addition/Modification
 * @{
 */
 
static struct nl_msg *class_build(struct rtnl_class *class, int type, int flags)
{
        struct rtnl_class_ops *cops;
        struct nl_msg *msg;
        int err;
 
        msg = tca_build_msg((struct rtnl_tca *) class, type, flags);
        if (!msg)
                goto errout;
 
        cops = rtnl_class_lookup_ops(class);
        if (cops && cops->co_get_opts) {
                struct nl_msg *opts;
                
                opts = cops->co_get_opts(class);
                if (opts) {
                        err = nla_put_nested(msg, TCA_OPTIONS, opts);
                        nlmsg_free(opts);
                        if (err < 0)
                                goto errout;
                }
        }
 
        return msg;
errout:
        nlmsg_free(msg);
        return NULL;
}
 
/**
 * Build a netlink message to add a new class
 * @arg class           class to add 
 * @arg flags           additional netlink message flags
 *
 * 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 New netlink message
 */
struct nl_msg *rtnl_class_build_add_request(struct rtnl_class *class, int flags)
{
        return class_build(class, RTM_NEWTCLASS, NLM_F_CREATE | flags);
}
 
/**
 * Add a new class
 * @arg handle          netlink handle
 * @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_handle *handle, struct rtnl_class *class,
                   int flags)
{
        struct nl_msg *msg;
        int err;
 
        msg = rtnl_class_build_add_request(class, flags);
        if (!msg)
                return nl_errno(ENOMEM);
 
        err = nl_send_auto_complete(handle, msg);
        nlmsg_free(msg);
        if (err < 0)
                return err;
 
        return nl_wait_for_ack(handle);
}
 
/** @} */
 
/**
 * @name Cache Management
 * @{
 */
 
/**
 * Build a class cache including all classes attached to the specified interface
 * @arg handle          netlink handle
 * @arg ifindex         interface index of the link the classes are
 *                      attached to.
 *
 * Allocates a new cache, initializes it properly and updates it to
 * include all classes attached to the specified interface.
 *
 * @return The cache or NULL if an error has occured.
 */
struct nl_cache * rtnl_class_alloc_cache(struct nl_handle *handle, int ifindex)
{
        struct nl_cache * cache;
        
        cache = nl_cache_alloc(&rtnl_class_ops);
        if (!cache)
                return NULL;
 
        cache->c_iarg1 = ifindex;
        
        if (handle && nl_cache_refill(handle, cache) < 0) {
                nl_cache_free(cache);
                return NULL;
        }
 
        return cache;
}
 
/** @} */
 
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)
{
        nl_cache_mngt_register(&rtnl_class_ops);
}
 
static void __exit class_exit(void)
{
        nl_cache_mngt_unregister(&rtnl_class_ops);
}
 
/** @} */