sfq.c

/*
 * lib/route/sch/sfq.c          SFQ Qdisc
 *
 *      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 qdisc_api
 * @defgroup sfq Stochastic Fairness Queueing (SFQ)
 * @brief
 *
 * @par Parameter Description
 * - \b Quantum: Number of bytes to send out per slot and round.
 * - \b Perturbation: Timer period between changing the hash function.
 * - \b Limit:  Upper limit of queue in number of packets before SFQ starts
 *              dropping packets.
 * - \b Divisor: Hash table divisor, i.e. size of hash table.
 * @{
 */
 
#include <netlink-local.h>
#include <netlink-tc.h>
#include <netlink/netlink.h>
#include <netlink/utils.h>
#include <netlink/route/qdisc.h>
#include <netlink/route/qdisc-modules.h>
#include <netlink/route/sch/sfq.h>
 
/** @cond SKIP */
#define SCH_SFQ_ATTR_QUANTUM    0x01
#define SCH_SFQ_ATTR_PERTURB    0x02
#define SCH_SFQ_ATTR_LIMIT      0x04
#define SCH_SFQ_ATTR_DIVISOR    0x08
#define SCH_SFQ_ATTR_FLOWS      0x10
/** @endcond */
 
static inline struct rtnl_sfq *sfq_qdisc(struct rtnl_qdisc *qdisc)
{
        return (struct rtnl_sfq *) qdisc->q_subdata;
}
 
static inline struct rtnl_sfq *sfq_alloc(struct rtnl_qdisc *qdisc)
{
        if (!qdisc->q_subdata)
                qdisc->q_subdata = calloc(1, sizeof(struct rtnl_sfq));
 
        return sfq_qdisc(qdisc);
}
 
static int sfq_msg_parser(struct rtnl_qdisc *qdisc)
{
        struct rtnl_sfq *sfq;
        struct tc_sfq_qopt *opts;
 
        if (!(qdisc->ce_mask & TCA_ATTR_OPTS))
                return 0;
 
        if (qdisc->q_opts->d_size < sizeof(*opts))
                return nl_error(EINVAL, "SFQ specific options size mismatch");
 
        sfq = sfq_alloc(qdisc);
        if (!sfq)
                return nl_errno(ENOMEM);
 
        opts = (struct tc_sfq_qopt *) qdisc->q_opts->d_data;
 
        sfq->qs_quantum = opts->quantum;
        sfq->qs_perturb = opts->perturb_period;
        sfq->qs_limit = opts->limit;
        sfq->qs_divisor = opts->divisor;
        sfq->qs_flows = opts->flows;
 
        sfq->qs_mask = (SCH_SFQ_ATTR_QUANTUM | SCH_SFQ_ATTR_PERTURB |
                        SCH_SFQ_ATTR_LIMIT | SCH_SFQ_ATTR_DIVISOR |
                        SCH_SFQ_ATTR_FLOWS);
 
        return 0;
}
 
static void sfq_free_data(struct rtnl_qdisc *qdisc)
{
        free(qdisc->q_subdata);
}
 
static int sfq_dump_brief(struct rtnl_qdisc *qdisc, struct nl_dump_params *p,
                          int line)
{
        struct rtnl_sfq *sfq = sfq_qdisc(qdisc);
 
        if (sfq)
                dp_dump(p, " quantum %u perturb %us",
                        sfq->qs_quantum,
                        nl_ticks2us(sfq->qs_perturb * nl_get_hz()));
 
        return line;
}
 
static int sfq_dump_full(struct rtnl_qdisc *qdisc, struct nl_dump_params *p,
                         int line)
{
        struct rtnl_sfq *sfq = sfq_qdisc(qdisc);
 
        if (sfq)
                dp_dump(p, "limit %u divisor %u",
                        sfq->qs_limit, sfq->qs_divisor);
 
        return line;
}
 
static struct nl_msg *sfq_get_opts(struct rtnl_qdisc *qdisc)
{
        struct rtnl_sfq *sfq;
        struct tc_sfq_qopt opts;
        struct nl_msg *msg;
 
        sfq = sfq_qdisc(qdisc);
        if (!sfq)
                return NULL;
 
        msg = nlmsg_alloc();
        if (!msg)
                goto errout;
 
        memset(&opts, 0, sizeof(opts));
        opts.quantum = sfq->qs_quantum;
        opts.perturb_period = sfq->qs_perturb;
        opts.limit = sfq->qs_limit;
 
        if (nlmsg_append(msg, &opts, sizeof(opts), NL_DONTPAD) < 0)
                goto errout;
 
        return msg;
errout:
        nlmsg_free(msg);
        return NULL;
}
 
/**
 * @name Attribute Access
 * @{
 */
 
/**
 * Set quantum of SFQ qdisc.
 * @arg qdisc           SFQ qdisc to be modified.
 * @arg quantum         New quantum in bytes.
 * @return 0 on success or a negative error code.
 */
int rtnl_sfq_set_quantum(struct rtnl_qdisc *qdisc, int quantum)
{
        struct rtnl_sfq *sfq;
        
        sfq = sfq_alloc(qdisc);
        if (!sfq)
                return nl_errno(ENOMEM);
 
        sfq->qs_quantum = quantum;
        sfq->qs_mask |= SCH_SFQ_ATTR_QUANTUM;
 
        return 0;
}
 
/**
 * Get quantum of SFQ qdisc.
 * @arg qdisc           SFQ qdisc.
 * @return Quantum in bytes or a negative error code.
 */
int rtnl_sfq_get_quantum(struct rtnl_qdisc *qdisc)
{
        struct rtnl_sfq *sfq;
 
        sfq = sfq_qdisc(qdisc);
        if (sfq && sfq->qs_mask & SCH_SFQ_ATTR_QUANTUM)
                return sfq->qs_quantum;
        else
                return nl_errno(ENOENT);
}
 
/**
 * Set limit of SFQ qdisc.
 * @arg qdisc           SFQ qdisc to be modified.
 * @arg limit           New limit in number of packets.
 * @return 0 on success or a negative error code.
 */
int rtnl_sfq_set_limit(struct rtnl_qdisc *qdisc, int limit)
{
        struct rtnl_sfq *sfq;
 
        sfq = sfq_alloc(qdisc);
        if (!sfq)
                return nl_errno(ENOMEM);
 
        sfq->qs_limit = limit;
        sfq->qs_mask |= SCH_SFQ_ATTR_LIMIT;
 
        return 0;
}
 
/**
 * Get limit of SFQ qdisc.
 * @arg qdisc           SFQ qdisc.
 * @return Limit or a negative error code.
 */
int rtnl_sfq_get_limit(struct rtnl_qdisc *qdisc)
{
        struct rtnl_sfq *sfq;
 
        sfq = sfq_qdisc(qdisc);
        if (sfq && sfq->qs_mask & SCH_SFQ_ATTR_LIMIT)
                return sfq->qs_limit;
        else
                return nl_errno(ENOENT);
}
 
/**
 * Set perturbation interval of SFQ qdisc.
 * @arg qdisc           SFQ qdisc to be modified.
 * @arg perturb         New perturbation interval in seconds.
 * @note A value of 0 disables perturbation altogether.
 * @return 0 on success or a negative error code.
 */
int rtnl_sfq_set_perturb(struct rtnl_qdisc *qdisc, int perturb)
{
        struct rtnl_sfq *sfq;
 
        sfq = sfq_alloc(qdisc);
        if (!sfq)
                return nl_errno(ENOMEM);
 
        sfq->qs_perturb = perturb;
        sfq->qs_mask |= SCH_SFQ_ATTR_PERTURB;
 
        return 0;
}
 
/**
 * Get perturbation interval of SFQ qdisc.
 * @arg qdisc           SFQ qdisc.
 * @return Perturbation interval in seconds or a negative error code.
 */
int rtnl_sfq_get_perturb(struct rtnl_qdisc *qdisc)
{
        struct rtnl_sfq *sfq;
 
        sfq = sfq_qdisc(qdisc);
        if (sfq && sfq->qs_mask & SCH_SFQ_ATTR_PERTURB)
                return sfq->qs_perturb;
        else
                return nl_errno(ENOENT);
}
 
/**
 * Get divisor of SFQ qdisc.
 * @arg qdisc           SFQ qdisc.
 * @return Divisor in number of entries or a negative error code.
 */
int rtnl_sfq_get_divisor(struct rtnl_qdisc *qdisc)
{
        struct rtnl_sfq *sfq;
 
        sfq = sfq_qdisc(qdisc);
        if (sfq && sfq->qs_mask & SCH_SFQ_ATTR_DIVISOR)
                return sfq->qs_divisor;
        else
                return nl_errno(ENOENT);
}
 
/** @} */
 
static struct rtnl_qdisc_ops sfq_ops = {
        .qo_kind                = "sfq",
        .qo_msg_parser          = sfq_msg_parser,
        .qo_free_data           = sfq_free_data,
        .qo_dump[NL_DUMP_BRIEF] = sfq_dump_brief,
        .qo_dump[NL_DUMP_FULL]  = sfq_dump_full,
        .qo_get_opts            = sfq_get_opts,
};
 
static void __init sfq_init(void)
{
        rtnl_qdisc_register(&sfq_ops);
}
 
static void __exit sfq_exit(void)
{
        rtnl_qdisc_unregister(&sfq_ops);
}
 
/** @} */