tbf.c

/*
 * lib/route/sch/tbf.c          TBF 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 tbf Token Bucket Filter (TBF)
 * @{
 */
 
#include <netlink-local.h>
#include <netlink-tc.h>
#include <netlink/netlink.h>
#include <netlink/cache.h>
#include <netlink/utils.h>
#include <netlink/route/tc.h>
#include <netlink/route/qdisc.h>
#include <netlink/route/qdisc-modules.h>
#include <netlink/route/class.h>
#include <netlink/route/class-modules.h>
#include <netlink/route/link.h>
#include <netlink/route/sch/tbf.h>
 
/** @cond SKIP */
#define TBF_ATTR_LIMIT                  0x01
#define TBF_ATTR_RATE                   0x02
#define TBF_ATTR_PEAKRATE               0x10
#define TBF_ATTR_MPU                    0x80
/** @endcond */
 
static inline struct rtnl_tbf *tbf_qdisc(struct rtnl_qdisc *qdisc)
{
        return (struct rtnl_tbf *) qdisc->q_subdata;
}
 
static inline struct rtnl_tbf *tbf_alloc(struct rtnl_qdisc *qdisc)
{
        if (!qdisc->q_subdata)
                qdisc->q_subdata = calloc(1, sizeof(struct rtnl_tbf));
 
        return tbf_qdisc(qdisc);
}
 
static struct nla_policy tbf_policy[TCA_TBF_MAX+1] = {
        [TCA_TBF_PARMS] = { .minlen = sizeof(struct tc_tbf_qopt) },
};
 
static int tbf_msg_parser(struct rtnl_qdisc *q)
{
        int err;
        struct nlattr *tb[TCA_TBF_MAX + 1];
        struct rtnl_tbf *tbf;
 
        err = tca_parse(tb, TCA_TBF_MAX, (struct rtnl_tca *) q, tbf_policy);
        if (err < 0)
                return err;
        
        tbf = tbf_qdisc(q);
        if (!tbf)
                return nl_errno(ENOMEM);
 
        if (tb[TCA_TBF_PARMS]) {
                struct tc_tbf_qopt opts;
                int bufsize;
 
                nla_memcpy(&opts, tb[TCA_TBF_PARMS], sizeof(opts));
                tbf->qt_limit = opts.limit;
                tbf->qt_mpu = opts.rate.mpu;
        
                rtnl_copy_ratespec(&tbf->qt_rate, &opts.rate);
                tbf->qt_rate_txtime = opts.buffer;
                bufsize = rtnl_tc_calc_bufsize(nl_ticks2us(opts.buffer),
                                               opts.rate.rate);
                tbf->qt_rate_bucket = bufsize;
 
                rtnl_copy_ratespec(&tbf->qt_peakrate, &opts.peakrate);
                tbf->qt_peakrate_txtime = opts.mtu;
                bufsize = rtnl_tc_calc_bufsize(nl_ticks2us(opts.mtu),
                                               opts.peakrate.rate);
                tbf->qt_peakrate_bucket = bufsize;
 
                tbf->qt_mask = (TBF_ATTR_LIMIT | TBF_ATTR_MPU | TBF_ATTR_RATE |
                                TBF_ATTR_PEAKRATE);
        }
 
        return 0;
}
 
static int tbf_dump_brief(struct rtnl_qdisc *qdisc, struct nl_dump_params *p,
                          int line)
{
        double r, rbit, lim;
        char *ru, *rubit, *limu;
        struct rtnl_tbf *tbf = tbf_qdisc(qdisc);
 
        if (!tbf)
                goto ignore;
 
        r = nl_cancel_down_bytes(tbf->qt_rate.rs_rate, &ru);
        rbit = nl_cancel_down_bits(tbf->qt_rate.rs_rate*8, &rubit);
        lim = nl_cancel_down_bytes(tbf->qt_limit, &limu);
 
        dp_dump(p, " rate %.2f%s/s (%.0f%s) limit %.2f%s",
                r, ru, rbit, rubit, lim, limu);
 
ignore:
        return line;
}
 
static int tbf_dump_full(struct rtnl_qdisc *qdisc, struct nl_dump_params *p,
                         int line)
{
        struct rtnl_tbf *tbf = tbf_qdisc(qdisc);
 
        if (!tbf)
                goto ignore;
 
        if (1) {
                char *bu, *cu;
                double bs = nl_cancel_down_bytes(tbf->qt_rate_bucket, &bu);
                double cl = nl_cancel_down_bytes(1 << tbf->qt_rate.rs_cell_log,
                                                 &cu);
 
                dp_dump(p, "mpu %u rate-bucket-size %1.f%s "
                           "rate-cell-size %.1f%s\n",
                        tbf->qt_mpu, bs, bu, cl, cu);
 
        }
 
        if (tbf->qt_mask & TBF_ATTR_PEAKRATE) {
                char *pru, *prbu, *bsu, *clu;
                double pr, prb, bs, cl;
                
                pr = nl_cancel_down_bytes(tbf->qt_peakrate.rs_rate, &pru);
                prb = nl_cancel_down_bits(tbf->qt_peakrate.rs_rate * 8, &prbu);
                bs = nl_cancel_down_bits(tbf->qt_peakrate_bucket, &bsu);
                cl = nl_cancel_down_bits(1 << tbf->qt_peakrate.rs_cell_log,
                                         &clu);
 
                dp_dump_line(p, line++, "    peak-rate %.2f%s/s (%.0f%s) "
                                        "bucket-size %.1f%s cell-size %.1f%s",
                                        "latency %.1f%s",
                             pr, pru, prb, prbu, bs, bsu, cl, clu);
        }
 
ignore:
        return line;
}
 
static struct nl_msg *tbf_get_opts(struct rtnl_qdisc *qdisc)
{
        struct tc_tbf_qopt opts;
        struct rtnl_tbf *tbf;
        struct nl_msg *msg;
        uint32_t rtab[RTNL_TC_RTABLE_SIZE];
        uint32_t ptab[RTNL_TC_RTABLE_SIZE];
        int required = TBF_ATTR_RATE | TBF_ATTR_LIMIT;
 
        memset(&opts, 0, sizeof(opts));
 
        tbf = tbf_qdisc(qdisc);
        if (!tbf)
                return NULL;
 
        if (!(tbf->qt_mask & required) != required)
                return NULL;
 
        opts.limit = tbf->qt_limit;
        opts.buffer = tbf->qt_rate_txtime;
        tbf->qt_rate.rs_mpu = tbf->qt_mpu;
        rtnl_rcopy_ratespec(&opts.rate, &tbf->qt_rate);
 
        rtnl_tc_build_rate_table(rtab, tbf->qt_mpu & 0xff, tbf->qt_mpu >> 8,
                                 1 << tbf->qt_rate.rs_cell_log,
                                 tbf->qt_rate.rs_rate);
 
        if (tbf->qt_mask & TBF_ATTR_PEAKRATE) {
                opts.mtu = tbf->qt_peakrate_txtime;
                tbf->qt_peakrate.rs_mpu = tbf->qt_mpu;
                rtnl_rcopy_ratespec(&opts.peakrate, &tbf->qt_peakrate);
 
                rtnl_tc_build_rate_table(ptab, tbf->qt_mpu & 0xff,
                                         tbf->qt_mpu >> 8,
                                         1 << tbf->qt_peakrate.rs_cell_log,
                                         tbf->qt_peakrate.rs_rate);
        }
 
        msg = nlmsg_alloc();
        if (!msg)
                goto nla_put_failure;
 
        NLA_PUT(msg, TCA_TBF_PARMS, sizeof(opts), &opts);
        NLA_PUT(msg, TCA_TBF_RTAB, sizeof(rtab), rtab);
 
        if (tbf->qt_mask & TBF_ATTR_PEAKRATE)
                NLA_PUT(msg, TCA_TBF_PTAB, sizeof(ptab), ptab);
 
        return msg;
 
nla_put_failure:
        nlmsg_free(msg);
        return NULL;
}
 
/**
 * @name Attribute Access
 * @{
 */
 
/**
 * Set limit of TBF qdisc.
 * @arg qdisc           TBF qdisc to be modified.
 * @arg limit           New limit in bytes.
 * @return 0 on success or a negative error code.
 */
int rtnl_qdisc_tbf_set_limit(struct rtnl_qdisc *qdisc, int limit)
{
        struct rtnl_tbf *tbf;
        
        tbf = tbf_alloc(qdisc);
        if (!tbf)
                return nl_errno(ENOMEM);
 
        tbf->qt_limit = limit;
        tbf->qt_mask |= TBF_ATTR_LIMIT;
 
        return 0;
}
 
static inline double calc_limit(struct rtnl_ratespec *spec, int latency,
                                int bucket)
{
        double limit;
 
        limit = (double) spec->rs_rate * ((double) latency / 1000000.);
        limit += bucket;
 
        return limit;
}
 
/**
 * Set limit of TBF qdisc by latency.
 * @arg qdisc           TBF qdisc to be modified.
 * @arg latency         Latency in micro seconds.
 *
 * Calculates and sets the limit based on the desired latency and the
 * configured rate and peak rate. In order for this operation to succeed,
 * the rate and if required the peak rate must have been set in advance.
 *
 * @f[
 *   limit_n = \frac{{rate_n} \times {latency}}{10^6}+{bucketsize}_n
 * @f]
 * @f[
 *   limit = min(limit_{rate},limit_{peak})
 * @f]
 * 
 * @return 0 on success or a negative error code.
 */
int rtnl_qdisc_tbf_set_limit_by_latency(struct rtnl_qdisc *qdisc, int latency)
{
        struct rtnl_tbf *tbf;
        double limit, limit2;
 
        tbf = tbf_alloc(qdisc);
        if (!tbf)
                return nl_errno(ENOMEM);
 
        if (!(tbf->qt_mask & TBF_ATTR_RATE))
                return nl_error(EINVAL, "The rate must be specified before "
                                "limit can be calculated based on latency.");
 
        limit = calc_limit(&tbf->qt_rate, latency, tbf->qt_rate_bucket);
 
        if (tbf->qt_mask & TBF_ATTR_PEAKRATE) {
                limit2 = calc_limit(&tbf->qt_peakrate, latency,
                                    tbf->qt_peakrate_bucket);
 
                if (limit2 < limit)
                        limit = limit2;
        }
 
        return rtnl_qdisc_tbf_set_limit(qdisc, (int) limit);
}
 
/**
 * Get limit of TBF qdisc.
 * @arg qdisc           TBF qdisc.
 * @return Limit in bytes or a negative error code.
 */
int rtnl_qdisc_tbf_get_limit(struct rtnl_qdisc *qdisc)
{
        struct rtnl_tbf *tbf;
        
        tbf = tbf_qdisc(qdisc);
        if (tbf && (tbf->qt_mask & TBF_ATTR_LIMIT))
                return tbf->qt_limit;
        return
                nl_errno(ENOENT);
}
 
/**
 * Set MPU of TBF qdisc.
 * @arg qdisc           TBF qdisc to be modified.
 * @arg mpu             New MPU in bytes.
 * @return 0 on success or a negative error code.
 */
int rtnl_qdisc_tbf_set_mpu(struct rtnl_qdisc *qdisc, int mpu)
{
        struct rtnl_tbf *tbf;
        
        tbf = tbf_alloc(qdisc);
        if (!tbf)
                return nl_errno(ENOMEM);
 
        tbf->qt_mpu = mpu;
        tbf->qt_mask |= TBF_ATTR_MPU;
 
        return 0;
}
 
/**
 * Get MPU of TBF qdisc.
 * @arg qdisc           TBF qdisc.
 * @return MPU in bytes or a negative error code.
 */
int rtnl_qdisc_tbf_get_mpu(struct rtnl_qdisc *qdisc)
{
        struct rtnl_tbf *tbf;
        
        tbf = tbf_qdisc(qdisc);
        if (tbf && (tbf->qt_mask & TBF_ATTR_MPU))
                return tbf->qt_mpu;
        return
                nl_errno(ENOENT);
}
 
static inline int calc_cell_log(int cell, int bucket)
{
        if (cell > 0)
                cell = rtnl_tc_calc_cell_log(cell);
        else {
                cell = 0;
 
                if (!bucket)
                        bucket = 2047; /* defaults to cell_log=3 */
 
                while ((bucket >> cell) > 255)
                        cell++;
        }
 
        return cell;
}
 
/**
 * Set rate of TBF qdisc.
 * @arg qdisc           TBF qdisc to be modified.
 * @arg rate            New rate in bytes per second.
 * @arg bucket          Size of bucket in bytes.
 * @arg cell            Size of a rate cell or 0 to get default value.
 * @return 0 on success or a negative error code.
 */
int rtnl_qdisc_tbf_set_rate(struct rtnl_qdisc *qdisc, int rate, int bucket,
                            int cell)
{
        struct rtnl_tbf *tbf;
        int cell_log;
        
        tbf = tbf_alloc(qdisc);
        if (!tbf)
                return nl_errno(ENOMEM);
 
        cell_log = calc_cell_log(cell, bucket);
        if (cell_log < 0)
                return cell_log;
 
        tbf->qt_rate.rs_rate = rate;
        tbf->qt_rate_bucket = bucket;
        tbf->qt_rate.rs_cell_log = cell_log;
        tbf->qt_rate_txtime = rtnl_tc_calc_txtime(bucket, rate);
        tbf->qt_mask |= TBF_ATTR_RATE;
 
        return 0;
}
 
/**
 * Get rate of TBF qdisc.
 * @arg qdisc           TBF qdisc.
 * @return Rate in bytes per seconds or a negative error code.
 */
int rtnl_qdisc_tbf_get_rate(struct rtnl_qdisc *qdisc)
{
        struct rtnl_tbf *tbf;
 
        tbf = tbf_qdisc(qdisc);
        if (tbf && (tbf->qt_mask & TBF_ATTR_RATE))
                return tbf->qt_rate.rs_rate;
        else
                return -1;
}
 
/**
 * Get rate bucket size of TBF qdisc.
 * @arg qdisc           TBF qdisc.
 * @return Size of rate bucket or a negative error code.
 */
int rtnl_qdisc_tbf_get_rate_bucket(struct rtnl_qdisc *qdisc)
{
        struct rtnl_tbf *tbf;
 
        tbf = tbf_qdisc(qdisc);
        if (tbf && (tbf->qt_mask & TBF_ATTR_RATE))
                return tbf->qt_rate_bucket;
        else
                return -1;
}
 
/**
 * Get rate cell size of TBF qdisc.
 * @arg qdisc           TBF qdisc.
 * @return Size of rate cell in bytes or a negative error code.
 */
int rtnl_qdisc_tbf_get_rate_cell(struct rtnl_qdisc *qdisc)
{
        struct rtnl_tbf *tbf;
 
        tbf = tbf_qdisc(qdisc);
        if (tbf && (tbf->qt_mask & TBF_ATTR_RATE))
                return (1 << tbf->qt_rate.rs_cell_log);
        else
                return -1;
}
 
/**
 * Set peak rate of TBF qdisc.
 * @arg qdisc           TBF qdisc to be modified.
 * @arg rate            New peak rate in bytes per second.
 * @arg bucket          Size of peakrate bucket.
 * @arg cell            Size of a peakrate cell or 0 to get default value.
 * @return 0 on success or a negative error code.
 */
int rtnl_qdisc_tbf_set_peakrate(struct rtnl_qdisc *qdisc, int rate, int bucket,
                                int cell)
{
        struct rtnl_tbf *tbf;
        int cell_log;
        
        tbf = tbf_alloc(qdisc);
        if (!tbf)
                return nl_errno(ENOMEM);
 
        cell_log = calc_cell_log(cell, bucket);
        if (cell_log < 0)
                return cell_log;
 
        tbf->qt_peakrate.rs_rate = rate;
        tbf->qt_peakrate_bucket = bucket;
        tbf->qt_peakrate.rs_cell_log = cell_log;
        tbf->qt_peakrate_txtime = rtnl_tc_calc_txtime(bucket, rate);
        
        tbf->qt_mask |= TBF_ATTR_PEAKRATE;
 
        return 0;
}
 
/**
 * Get peak rate of TBF qdisc.
 * @arg qdisc           TBF qdisc.
 * @return Peak rate in bytes per seconds or a negative error code.
 */
int rtnl_qdisc_tbf_get_peakrate(struct rtnl_qdisc *qdisc)
{
        struct rtnl_tbf *tbf;
 
        tbf = tbf_qdisc(qdisc);
        if (tbf && (tbf->qt_mask & TBF_ATTR_PEAKRATE))
                return tbf->qt_peakrate.rs_rate;
        else
                return -1;
}
 
/**
 * Get peak rate bucket size of TBF qdisc.
 * @arg qdisc           TBF qdisc.
 * @return Size of peak rate bucket or a negative error code.
 */
int rtnl_qdisc_tbf_get_peakrate_bucket(struct rtnl_qdisc *qdisc)
{
        struct rtnl_tbf *tbf;
 
        tbf = tbf_qdisc(qdisc);
        if (tbf && (tbf->qt_mask & TBF_ATTR_PEAKRATE))
                return tbf->qt_peakrate_bucket;
        else
                return -1;
}
 
/**
 * Get peak rate cell size of TBF qdisc.
 * @arg qdisc           TBF qdisc.
 * @return Size of peak rate cell in bytes or a negative error code.
 */
int rtnl_qdisc_tbf_get_peakrate_cell(struct rtnl_qdisc *qdisc)
{
        struct rtnl_tbf *tbf;
 
        tbf = tbf_qdisc(qdisc);
        if (tbf && (tbf->qt_mask & TBF_ATTR_PEAKRATE))
                return (1 << tbf->qt_peakrate.rs_cell_log);
        else
                return -1;
}
 
/** @} */
 
static struct rtnl_qdisc_ops tbf_qdisc_ops = {
        .qo_kind                = "tbf",
        .qo_msg_parser          = tbf_msg_parser,
        .qo_dump[NL_DUMP_BRIEF] = tbf_dump_brief,
        .qo_dump[NL_DUMP_FULL]  = tbf_dump_full,
        .qo_get_opts            = tbf_get_opts,
};
 
static void __init tbf_init(void)
{
        rtnl_qdisc_register(&tbf_qdisc_ops);
}
 
static void __exit tbf_exit(void)
{
        rtnl_qdisc_unregister(&tbf_qdisc_ops);
}
 
/** @} */