Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 543 insertions, 0 deletions

diff --git a/net/sched/sch_tbf.c b/net/sched/sch_tbf.c
new file mode 100644
index 000000000000..cb9711ea8c6c
--- /dev/null
+++ b/net/sched/sch_tbf.c
@@ -0,0 +1,543 @@
+/*
+ * net/sched/sch_tbf.c  Token Bucket Filter queue.
+ *
+ *              This program is free software; you can redistribute it and/or
+ *              modify it under the terms of the GNU General Public License
+ *              as published by the Free Software Foundation; either version
+ *              2 of the License, or (at your option) any later version.
+ *
+ * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *              Dmitry Torokhov <dtor@mail.ru> - allow attaching inner qdiscs -
+ *                                               original idea by Martin Devera
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/bitops.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/jiffies.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/in.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/if_ether.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/notifier.h>
+#include <net/ip.h>
+#include <net/route.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/pkt_sched.h>
+
+
+/*      Simple Token Bucket Filter.
+        =======================================
+
+        SOURCE.
+        -------
+
+        None.
+
+        Description.
+        ------------
+
+        A data flow obeys TBF with rate R and depth B, if for any
+        time interval t_i...t_f the number of transmitted bits
+        does not exceed B + R*(t_f-t_i).
+
+        Packetized version of this definition:
+        The sequence of packets of sizes s_i served at moments t_i
+        obeys TBF, if for any i<=k:
+
+        s_i+....+s_k <= B + R*(t_k - t_i)
+
+        Algorithm.
+        ----------
+
+        Let N(t_i) be B/R initially and N(t) grow continuously with time as:
+
+        N(t+delta) = min{B/R, N(t) + delta}
+
+        If the first packet in queue has length S, it may be
+        transmitted only at the time t_* when S/R <= N(t_*),
+        and in this case N(t) jumps:
+
+        N(t_* + 0) = N(t_* - 0) - S/R.
+
+
+
+        Actually, QoS requires two TBF to be applied to a data stream.
+        One of them controls steady state burst size, another
+        one with rate P (peak rate) and depth M (equal to link MTU)
+        limits bursts at a smaller time scale.
+
+        It is easy to see that P>R, and B>M. If P is infinity, this double
+        TBF is equivalent to a single one.
+
+        When TBF works in reshaping mode, latency is estimated as:
+
+        lat = max ((L-B)/R, (L-M)/P)
+
+
+        NOTES.
+        ------
+
+        If TBF throttles, it starts a watchdog timer, which will wake it up
+        when it is ready to transmit.
+        Note that the minimal timer resolution is 1/HZ.
+        If no new packets arrive during this period,
+        or if the device is not awaken by EOI for some previous packet,
+        TBF can stop its activity for 1/HZ.
+
+
+        This means, that with depth B, the maximal rate is
+
+        R_crit = B*HZ
+
+        F.e. for 10Mbit ethernet and HZ=100 the minimal allowed B is ~10Kbytes.
+
+        Note that the peak rate TBF is much more tough: with MTU 1500
+        P_crit = 150Kbytes/sec. So, if you need greater peak
+        rates, use alpha with HZ=1000 :-)
+
+        With classful TBF, limit is just kept for backwards compatibility.
+        It is passed to the default bfifo qdisc - if the inner qdisc is
+        changed the limit is not effective anymore.
+*/
+
+struct tbf_sched_data
+{
+/* Parameters */
+        u32             limit;          /* Maximal length of backlog: bytes */
+        u32             buffer;         /* Token bucket depth/rate: MUST BE >= MTU/B */
+        u32             mtu;
+        u32             max_size;
+        struct qdisc_rate_table *R_tab;
+        struct qdisc_rate_table *P_tab;
+
+/* Variables */
+        long    tokens;                 /* Current number of B tokens */
+        long    ptokens;                /* Current number of P tokens */
+        psched_time_t   t_c;            /* Time check-point */
+        struct timer_list wd_timer;     /* Watchdog timer */
+        struct Qdisc    *qdisc;         /* Inner qdisc, default - bfifo queue */
+};
+
+#define L2T(q,L)   ((q)->R_tab->data[(L)>>(q)->R_tab->rate.cell_log])
+#define L2T_P(q,L) ((q)->P_tab->data[(L)>>(q)->P_tab->rate.cell_log])
+
+static int tbf_enqueue(struct sk_buff *skb, struct Qdisc* sch)
+{
+        struct tbf_sched_data *q = qdisc_priv(sch);
+        int ret;
+
+        if (skb->len > q->max_size) {
+                sch->qstats.drops++;
+#ifdef CONFIG_NET_CLS_POLICE
+                if (sch->reshape_fail == NULL || sch->reshape_fail(skb, sch))
+#endif
+                        kfree_skb(skb);
+
+                return NET_XMIT_DROP;
+        }
+
+        if ((ret = q->qdisc->enqueue(skb, q->qdisc)) != 0) {
+                sch->qstats.drops++;
+                return ret;
+        }
+
+        sch->q.qlen++;
+        sch->bstats.bytes += skb->len;
+        sch->bstats.packets++;
+        return 0;
+}
+
+static int tbf_requeue(struct sk_buff *skb, struct Qdisc* sch)
+{
+        struct tbf_sched_data *q = qdisc_priv(sch);
+        int ret;
+
+        if ((ret = q->qdisc->ops->requeue(skb, q->qdisc)) == 0) {
+                sch->q.qlen++;
+                sch->qstats.requeues++;
+        }
+
+        return ret;
+}
+
+static unsigned int tbf_drop(struct Qdisc* sch)
+{
+        struct tbf_sched_data *q = qdisc_priv(sch);
+        unsigned int len;
+
+        if ((len = q->qdisc->ops->drop(q->qdisc)) != 0) {
+                sch->q.qlen--;
+                sch->qstats.drops++;
+        }
+        return len;
+}
+
+static void tbf_watchdog(unsigned long arg)
+{
+        struct Qdisc *sch = (struct Qdisc*)arg;
+
+        sch->flags &= ~TCQ_F_THROTTLED;
+        netif_schedule(sch->dev);
+}
+
+static struct sk_buff *tbf_dequeue(struct Qdisc* sch)
+{
+        struct tbf_sched_data *q = qdisc_priv(sch);
+        struct sk_buff *skb;
+
+        skb = q->qdisc->dequeue(q->qdisc);
+
+        if (skb) {
+                psched_time_t now;
+                long toks, delay;
+                long ptoks = 0;
+                unsigned int len = skb->len;
+
+                PSCHED_GET_TIME(now);
+
+                toks = PSCHED_TDIFF_SAFE(now, q->t_c, q->buffer);
+
+                if (q->P_tab) {
+                        ptoks = toks + q->ptokens;
+                        if (ptoks > (long)q->mtu)
+                                ptoks = q->mtu;
+                        ptoks -= L2T_P(q, len);
+                }
+                toks += q->tokens;
+                if (toks > (long)q->buffer)
+                        toks = q->buffer;
+                toks -= L2T(q, len);
+
+                if ((toks|ptoks) >= 0) {
+                        q->t_c = now;
+                        q->tokens = toks;
+                        q->ptokens = ptoks;
+                        sch->q.qlen--;
+                        sch->flags &= ~TCQ_F_THROTTLED;
+                        return skb;
+                }
+
+                delay = PSCHED_US2JIFFIE(max_t(long, -toks, -ptoks));
+
+                if (delay == 0)
+                        delay = 1;
+
+                mod_timer(&q->wd_timer, jiffies+delay);
+
+                /* Maybe we have a shorter packet in the queue,
+                   which can be sent now. It sounds cool,
+                   but, however, this is wrong in principle.
+                   We MUST NOT reorder packets under these circumstances.
+
+                   Really, if we split the flow into independent
+                   subflows, it would be a very good solution.
+                   This is the main idea of all FQ algorithms
+                   (cf. CSZ, HPFQ, HFSC)
+                 */
+
+                if (q->qdisc->ops->requeue(skb, q->qdisc) != NET_XMIT_SUCCESS) {
+                        /* When requeue fails skb is dropped */
+                        sch->q.qlen--;
+                        sch->qstats.drops++;
+                }
+
+                sch->flags |= TCQ_F_THROTTLED;
+                sch->qstats.overlimits++;
+        }
+        return NULL;
+}
+
+static void tbf_reset(struct Qdisc* sch)
+{
+        struct tbf_sched_data *q = qdisc_priv(sch);
+
+        qdisc_reset(q->qdisc);
+        sch->q.qlen = 0;
+        PSCHED_GET_TIME(q->t_c);
+        q->tokens = q->buffer;
+        q->ptokens = q->mtu;
+        sch->flags &= ~TCQ_F_THROTTLED;
+        del_timer(&q->wd_timer);
+}
+
+static struct Qdisc *tbf_create_dflt_qdisc(struct net_device *dev, u32 limit)
+{
+        struct Qdisc *q = qdisc_create_dflt(dev, &bfifo_qdisc_ops);
+        struct rtattr *rta;
+        int ret;
+
+        if (q) {
+                rta = kmalloc(RTA_LENGTH(sizeof(struct tc_fifo_qopt)), GFP_KERNEL);
+                if (rta) {
+                        rta->rta_type = RTM_NEWQDISC;
+                        rta->rta_len = RTA_LENGTH(sizeof(struct tc_fifo_qopt)); 
+                        ((struct tc_fifo_qopt *)RTA_DATA(rta))->limit = limit;
+
+                        ret = q->ops->change(q, rta);
+                        kfree(rta);
+
+                        if (ret == 0)
+                                return q;
+                }
+                qdisc_destroy(q);
+        }
+
+        return NULL;
+}
+
+static int tbf_change(struct Qdisc* sch, struct rtattr *opt)
+{
+        int err = -EINVAL;
+        struct tbf_sched_data *q = qdisc_priv(sch);
+        struct rtattr *tb[TCA_TBF_PTAB];
+        struct tc_tbf_qopt *qopt;
+        struct qdisc_rate_table *rtab = NULL;
+        struct qdisc_rate_table *ptab = NULL;
+        struct Qdisc *child = NULL;
+        int max_size,n;
+
+        if (rtattr_parse_nested(tb, TCA_TBF_PTAB, opt) ||
+            tb[TCA_TBF_PARMS-1] == NULL ||
+            RTA_PAYLOAD(tb[TCA_TBF_PARMS-1]) < sizeof(*qopt))
+                goto done;
+
+        qopt = RTA_DATA(tb[TCA_TBF_PARMS-1]);
+        rtab = qdisc_get_rtab(&qopt->rate, tb[TCA_TBF_RTAB-1]);
+        if (rtab == NULL)
+                goto done;
+
+        if (qopt->peakrate.rate) {
+                if (qopt->peakrate.rate > qopt->rate.rate)
+                        ptab = qdisc_get_rtab(&qopt->peakrate, tb[TCA_TBF_PTAB-1]);
+                if (ptab == NULL)
+                        goto done;
+        }
+
+        for (n = 0; n < 256; n++)
+                if (rtab->data[n] > qopt->buffer) break;
+        max_size = (n << qopt->rate.cell_log)-1;
+        if (ptab) {
+                int size;
+
+                for (n = 0; n < 256; n++)
+                        if (ptab->data[n] > qopt->mtu) break;
+                size = (n << qopt->peakrate.cell_log)-1;
+                if (size < max_size) max_size = size;
+        }
+        if (max_size < 0)
+                goto done;
+
+        if (q->qdisc == &noop_qdisc) {
+                if ((child = tbf_create_dflt_qdisc(sch->dev, qopt->limit)) == NULL)
+                        goto done;
+        }
+
+        sch_tree_lock(sch);
+        if (child) q->qdisc = child;
+        q->limit = qopt->limit;
+        q->mtu = qopt->mtu;
+        q->max_size = max_size;
+        q->buffer = qopt->buffer;
+        q->tokens = q->buffer;
+        q->ptokens = q->mtu;
+        rtab = xchg(&q->R_tab, rtab);
+        ptab = xchg(&q->P_tab, ptab);
+        sch_tree_unlock(sch);
+        err = 0;
+done:
+        if (rtab)
+                qdisc_put_rtab(rtab);
+        if (ptab)
+                qdisc_put_rtab(ptab);
+        return err;
+}
+
+static int tbf_init(struct Qdisc* sch, struct rtattr *opt)
+{
+        struct tbf_sched_data *q = qdisc_priv(sch);
+
+        if (opt == NULL)
+                return -EINVAL;
+
+        PSCHED_GET_TIME(q->t_c);
+        init_timer(&q->wd_timer);
+        q->wd_timer.function = tbf_watchdog;
+        q->wd_timer.data = (unsigned long)sch;
+
+        q->qdisc = &noop_qdisc;
+
+        return tbf_change(sch, opt);
+}
+
+static void tbf_destroy(struct Qdisc *sch)
+{
+        struct tbf_sched_data *q = qdisc_priv(sch);
+
+        del_timer(&q->wd_timer);
+
+        if (q->P_tab)
+                qdisc_put_rtab(q->P_tab);
+        if (q->R_tab)
+                qdisc_put_rtab(q->R_tab);
+
+        qdisc_destroy(q->qdisc);
+}
+
+static int tbf_dump(struct Qdisc *sch, struct sk_buff *skb)
+{
+        struct tbf_sched_data *q = qdisc_priv(sch);
+        unsigned char    *b = skb->tail;
+        struct rtattr *rta;
+        struct tc_tbf_qopt opt;
+
+        rta = (struct rtattr*)b;
+        RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
+
+        opt.limit = q->limit;
+        opt.rate = q->R_tab->rate;
+        if (q->P_tab)
+                opt.peakrate = q->P_tab->rate;
+        else
+                memset(&opt.peakrate, 0, sizeof(opt.peakrate));
+        opt.mtu = q->mtu;
+        opt.buffer = q->buffer;
+        RTA_PUT(skb, TCA_TBF_PARMS, sizeof(opt), &opt);
+        rta->rta_len = skb->tail - b;
+
+        return skb->len;
+
+rtattr_failure:
+        skb_trim(skb, b - skb->data);
+        return -1;
+}
+
+static int tbf_dump_class(struct Qdisc *sch, unsigned long cl,
+                          struct sk_buff *skb, struct tcmsg *tcm)
+{
+        struct tbf_sched_data *q = qdisc_priv(sch);
+
+        if (cl != 1)    /* only one class */
+                return -ENOENT;
+
+        tcm->tcm_handle |= TC_H_MIN(1);
+        tcm->tcm_info = q->qdisc->handle;
+
+        return 0;
+}
+
+static int tbf_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
+                     struct Qdisc **old)
+{
+        struct tbf_sched_data *q = qdisc_priv(sch);
+
+        if (new == NULL)
+                new = &noop_qdisc;
+
+        sch_tree_lock(sch);
+        *old = xchg(&q->qdisc, new);
+        qdisc_reset(*old);
+        sch->q.qlen = 0;
+        sch_tree_unlock(sch);
+
+        return 0;
+}
+
+static struct Qdisc *tbf_leaf(struct Qdisc *sch, unsigned long arg)
+{
+        struct tbf_sched_data *q = qdisc_priv(sch);
+        return q->qdisc;
+}
+
+static unsigned long tbf_get(struct Qdisc *sch, u32 classid)
+{
+        return 1;
+}
+
+static void tbf_put(struct Qdisc *sch, unsigned long arg)
+{
+}
+
+static int tbf_change_class(struct Qdisc *sch, u32 classid, u32 parentid, 
+                            struct rtattr **tca, unsigned long *arg)
+{
+        return -ENOSYS;
+}
+
+static int tbf_delete(struct Qdisc *sch, unsigned long arg)
+{
+        return -ENOSYS;
+}
+
+static void tbf_walk(struct Qdisc *sch, struct qdisc_walker *walker)
+{
+        if (!walker->stop) {
+                if (walker->count >= walker->skip)
+                        if (walker->fn(sch, 1, walker) < 0) {
+                                walker->stop = 1;
+                                return;
+                        }
+                walker->count++;
+        }
+}
+
+static struct tcf_proto **tbf_find_tcf(struct Qdisc *sch, unsigned long cl)
+{
+        return NULL;
+}
+
+static struct Qdisc_class_ops tbf_class_ops =
+{
+        .graft          =       tbf_graft,
+        .leaf           =       tbf_leaf,
+        .get            =       tbf_get,
+        .put            =       tbf_put,
+        .change         =       tbf_change_class,
+        .delete         =       tbf_delete,
+        .walk           =       tbf_walk,
+        .tcf_chain      =       tbf_find_tcf,
+        .dump           =       tbf_dump_class,
+};
+
+static struct Qdisc_ops tbf_qdisc_ops = {
+        .next           =       NULL,
+        .cl_ops         =       &tbf_class_ops,
+        .id             =       "tbf",
+        .priv_size      =       sizeof(struct tbf_sched_data),
+        .enqueue        =       tbf_enqueue,
+        .dequeue        =       tbf_dequeue,
+        .requeue        =       tbf_requeue,
+        .drop           =       tbf_drop,
+        .init           =       tbf_init,
+        .reset          =       tbf_reset,
+        .destroy        =       tbf_destroy,
+        .change         =       tbf_change,
+        .dump           =       tbf_dump,
+        .owner          =       THIS_MODULE,
+};
+
+static int __init tbf_module_init(void)
+{
+        return register_qdisc(&tbf_qdisc_ops);
+}
+
+static void __exit tbf_module_exit(void)
+{
+        unregister_qdisc(&tbf_qdisc_ops);
+}
+module_init(tbf_module_init)
+module_exit(tbf_module_exit)
+MODULE_LICENSE("GPL");