Merge branch 'red' of 84.73.165.173:/home/tgr/repos/net-2.6

5 files changed, 891 insertions, 771 deletions

diff --git a/include/linux/pkt_sched.h b/include/linux/pkt_sched.h
index 60ffcb9c5791..e87b233615b3 100644
--- a/include/linux/pkt_sched.h
+++ b/include/linux/pkt_sched.h
@@ -93,6 +93,7 @@ struct tc_fifo_qopt
 /* PRIO section */
 
 #define TCQ_PRIO_BANDS  16
+#define TCQ_MIN_PRIO_BANDS 2
 
 struct tc_prio_qopt
 {
@@ -169,6 +170,7 @@ struct tc_red_qopt
         unsigned char   Scell_log;      /* cell size for idle damping */
         unsigned char   flags;
 #define TC_RED_ECN      1
+#define TC_RED_HARDDROP 2
 };
 
 struct tc_red_xstats
@@ -194,38 +196,34 @@ enum
 
 #define TCA_GRED_MAX (__TCA_GRED_MAX - 1)
 
-#define TCA_SET_OFF TCA_GRED_PARMS
 struct tc_gred_qopt
 {
-       __u32           limit;          /* HARD maximal queue length (bytes)    
-*/
-       __u32           qth_min;        /* Min average length threshold (bytes) 
-*/
-       __u32           qth_max;        /* Max average length threshold (bytes) 
-*/
-       __u32           DP;             /* upto 2^32 DPs */
-       __u32           backlog;        
-       __u32           qave;   
-       __u32           forced; 
-       __u32           early;  
-       __u32           other;  
-       __u32           pdrop;  
-
-       unsigned char   Wlog;           /* log(W)               */
-       unsigned char   Plog;           /* log(P_max/(qth_max-qth_min)) */
-       unsigned char   Scell_log;      /* cell size for idle damping */
-       __u8            prio;            /* prio of this VQ */
-       __u32    packets;
-       __u32    bytesin;
+        __u32           limit;        /* HARD maximal queue length (bytes)    */
+        __u32           qth_min;      /* Min average length threshold (bytes) */
+        __u32           qth_max;      /* Max average length threshold (bytes) */
+        __u32           DP;           /* upto 2^32 DPs */
+        __u32           backlog;
+        __u32           qave;
+        __u32           forced;
+        __u32           early;
+        __u32           other;
+        __u32           pdrop;
+        __u8            Wlog;         /* log(W)               */
+        __u8            Plog;         /* log(P_max/(qth_max-qth_min)) */
+        __u8            Scell_log;    /* cell size for idle damping */
+        __u8            prio;         /* prio of this VQ */
+        __u32           packets;
+        __u32           bytesin;
 };
+
 /* gred setup */
 struct tc_gred_sopt
 {
-       __u32            DPs;
-       __u32            def_DP;
-       __u8             grio;
-       __u8             pad1;
-       __u16            pad2;
+        __u32           DPs;
+        __u32           def_DP;
+        __u8            grio;
+        __u8            flags;
+        __u16           pad1;
 };
 
 /* HTB section */
diff --git a/include/net/inet_ecn.h b/include/net/inet_ecn.h
index f87845e2e965..b0c47e2eccf1 100644
--- a/include/net/inet_ecn.h
+++ b/include/net/inet_ecn.h
@@ -2,6 +2,7 @@
 #define _INET_ECN_H_
 
 #include <linux/ip.h>
+#include <linux/skbuff.h>
 #include <net/dsfield.h>
 
 enum {
@@ -48,7 +49,7 @@ static inline __u8 INET_ECN_encapsulate(__u8 outer, __u8 inner)
                 (label) |= __constant_htons(INET_ECN_ECT_0 << 4);       \
     } while (0)
 
-static inline void IP_ECN_set_ce(struct iphdr *iph)
+static inline int IP_ECN_set_ce(struct iphdr *iph)
 {
         u32 check = iph->check;
         u32 ecn = (iph->tos + 1) & INET_ECN_MASK;
@@ -61,7 +62,7 @@ static inline void IP_ECN_set_ce(struct iphdr *iph)
          * INET_ECN_CE      => 00
          */
         if (!(ecn & 2))
-                return;
+                return !ecn;
 
         /*
          * The following gives us:
@@ -72,6 +73,7 @@ static inline void IP_ECN_set_ce(struct iphdr *iph)
 
         iph->check = check + (check>=0xFFFF);
         iph->tos |= INET_ECN_CE;
+        return 1;
 }
 
 static inline void IP_ECN_clear(struct iphdr *iph)
@@ -87,11 +89,12 @@ static inline void ipv4_copy_dscp(struct iphdr *outer, struct iphdr *inner)
 
 struct ipv6hdr;
 
-static inline void IP6_ECN_set_ce(struct ipv6hdr *iph)
+static inline int IP6_ECN_set_ce(struct ipv6hdr *iph)
 {
         if (INET_ECN_is_not_ect(ipv6_get_dsfield(iph)))
-                return;
+                return 0;
         *(u32*)iph |= htonl(INET_ECN_CE << 20);
+        return 1;
 }
 
 static inline void IP6_ECN_clear(struct ipv6hdr *iph)
@@ -105,4 +108,21 @@ static inline void ipv6_copy_dscp(struct ipv6hdr *outer, struct ipv6hdr *inner)
         ipv6_change_dsfield(inner, INET_ECN_MASK, dscp);
 }
 
+static inline int INET_ECN_set_ce(struct sk_buff *skb)
+{
+        switch (skb->protocol) {
+        case __constant_htons(ETH_P_IP):
+                if (skb->nh.raw + sizeof(struct iphdr) <= skb->tail)
+                        return IP_ECN_set_ce(skb->nh.iph);
+                break;
+
+        case __constant_htons(ETH_P_IPV6):
+                if (skb->nh.raw + sizeof(struct ipv6hdr) <= skb->tail)
+                        return IP6_ECN_set_ce(skb->nh.ipv6h);
+                break;
+        }
+
+        return 0;
+}
+
 #endif
diff --git a/include/net/red.h b/include/net/red.h
new file mode 100644
index 000000000000..2ed4358e3295
--- /dev/null
+++ b/include/net/red.h
@@ -0,0 +1,325 @@
+#ifndef __NET_SCHED_RED_H
+#define __NET_SCHED_RED_H
+
+#include <linux/config.h>
+#include <linux/types.h>
+#include <net/pkt_sched.h>
+#include <net/inet_ecn.h>
+#include <net/dsfield.h>
+
+/*      Random Early Detection (RED) algorithm.
+        =======================================
+
+        Source: Sally Floyd and Van Jacobson, "Random Early Detection Gateways
+        for Congestion Avoidance", 1993, IEEE/ACM Transactions on Networking.
+
+        This file codes a "divisionless" version of RED algorithm
+        as written down in Fig.17 of the paper.
+
+        Short description.
+        ------------------
+
+        When a new packet arrives we calculate the average queue length:
+
+        avg = (1-W)*avg + W*current_queue_len,
+
+        W is the filter time constant (chosen as 2^(-Wlog)), it controls
+        the inertia of the algorithm. To allow larger bursts, W should be
+        decreased.
+
+        if (avg > th_max) -> packet marked (dropped).
+        if (avg < th_min) -> packet passes.
+        if (th_min < avg < th_max) we calculate probability:
+
+        Pb = max_P * (avg - th_min)/(th_max-th_min)
+
+        and mark (drop) packet with this probability.
+        Pb changes from 0 (at avg==th_min) to max_P (avg==th_max).
+        max_P should be small (not 1), usually 0.01..0.02 is good value.
+
+        max_P is chosen as a number, so that max_P/(th_max-th_min)
+        is a negative power of two in order arithmetics to contain
+        only shifts.
+
+
+        Parameters, settable by user:
+        -----------------------------
+
+        qth_min         - bytes (should be < qth_max/2)
+        qth_max         - bytes (should be at least 2*qth_min and less limit)
+        Wlog            - bits (<32) log(1/W).
+        Plog            - bits (<32)
+
+        Plog is related to max_P by formula:
+
+        max_P = (qth_max-qth_min)/2^Plog;
+
+        F.e. if qth_max=128K and qth_min=32K, then Plog=22
+        corresponds to max_P=0.02
+
+        Scell_log
+        Stab
+
+        Lookup table for log((1-W)^(t/t_ave).
+
+
+        NOTES:
+
+        Upper bound on W.
+        -----------------
+
+        If you want to allow bursts of L packets of size S,
+        you should choose W:
+
+        L + 1 - th_min/S < (1-(1-W)^L)/W
+
+        th_min/S = 32         th_min/S = 4
+
+        log(W)  L
+        -1      33
+        -2      35
+        -3      39
+        -4      46
+        -5      57
+        -6      75
+        -7      101
+        -8      135
+        -9      190
+        etc.
+ */
+
+#define RED_STAB_SIZE   256
+#define RED_STAB_MASK   (RED_STAB_SIZE - 1)
+
+struct red_stats
+{
+        u32             prob_drop;      /* Early probability drops */
+        u32             prob_mark;      /* Early probability marks */
+        u32             forced_drop;    /* Forced drops, qavg > max_thresh */
+        u32             forced_mark;    /* Forced marks, qavg > max_thresh */
+        u32             pdrop;          /* Drops due to queue limits */
+        u32             other;          /* Drops due to drop() calls */
+        u32             backlog;
+};
+
+struct red_parms
+{
+        /* Parameters */
+        u32             qth_min;        /* Min avg length threshold: A scaled */
+        u32             qth_max;        /* Max avg length threshold: A scaled */
+        u32             Scell_max;
+        u32             Rmask;          /* Cached random mask, see red_rmask */
+        u8              Scell_log;
+        u8              Wlog;           /* log(W)               */
+        u8              Plog;           /* random number bits   */
+        u8              Stab[RED_STAB_SIZE];
+
+        /* Variables */
+        int             qcount;         /* Number of packets since last random
+                                           number generation */
+        u32             qR;             /* Cached random number */
+
+        unsigned long   qavg;           /* Average queue length: A scaled */
+        psched_time_t   qidlestart;     /* Start of current idle period */
+};
+
+static inline u32 red_rmask(u8 Plog)
+{
+        return Plog < 32 ? ((1 << Plog) - 1) : ~0UL;
+}
+
+static inline void red_set_parms(struct red_parms *p,
+                                 u32 qth_min, u32 qth_max, u8 Wlog, u8 Plog,
+                                 u8 Scell_log, u8 *stab)
+{
+        /* Reset average queue length, the value is strictly bound
+         * to the parameters below, reseting hurts a bit but leaving
+         * it might result in an unreasonable qavg for a while. --TGR
+         */
+        p->qavg         = 0;
+
+        p->qcount       = -1;
+        p->qth_min      = qth_min << Wlog;
+        p->qth_max      = qth_max << Wlog;
+        p->Wlog         = Wlog;
+        p->Plog         = Plog;
+        p->Rmask        = red_rmask(Plog);
+        p->Scell_log    = Scell_log;
+        p->Scell_max    = (255 << Scell_log);
+
+        memcpy(p->Stab, stab, sizeof(p->Stab));
+}
+
+static inline int red_is_idling(struct red_parms *p)
+{
+        return !PSCHED_IS_PASTPERFECT(p->qidlestart);
+}
+
+static inline void red_start_of_idle_period(struct red_parms *p)
+{
+        PSCHED_GET_TIME(p->qidlestart);
+}
+
+static inline void red_end_of_idle_period(struct red_parms *p)
+{
+        PSCHED_SET_PASTPERFECT(p->qidlestart);
+}
+
+static inline void red_restart(struct red_parms *p)
+{
+        red_end_of_idle_period(p);
+        p->qavg = 0;
+        p->qcount = -1;
+}
+
+static inline unsigned long red_calc_qavg_from_idle_time(struct red_parms *p)
+{
+        psched_time_t now;
+        long us_idle;
+        int  shift;
+
+        PSCHED_GET_TIME(now);
+        us_idle = PSCHED_TDIFF_SAFE(now, p->qidlestart, p->Scell_max);
+
+        /*
+         * The problem: ideally, average length queue recalcultion should
+         * be done over constant clock intervals. This is too expensive, so
+         * that the calculation is driven by outgoing packets.
+         * When the queue is idle we have to model this clock by hand.
+         *
+         * SF+VJ proposed to "generate":
+         *
+         *      m = idletime / (average_pkt_size / bandwidth)
+         *
+         * dummy packets as a burst after idle time, i.e.
+         *
+         *      p->qavg *= (1-W)^m
+         *
+         * This is an apparently overcomplicated solution (f.e. we have to
+         * precompute a table to make this calculation in reasonable time)
+         * I believe that a simpler model may be used here,
+         * but it is field for experiments.
+         */
+
+        shift = p->Stab[(us_idle >> p->Scell_log) & RED_STAB_MASK];
+
+        if (shift)
+                return p->qavg >> shift;
+        else {
+                /* Approximate initial part of exponent with linear function:
+                 *
+                 *      (1-W)^m ~= 1-mW + ...
+                 *
+                 * Seems, it is the best solution to
+                 * problem of too coarse exponent tabulation.
+                 */
+                us_idle = (p->qavg * us_idle) >> p->Scell_log;
+
+                if (us_idle < (p->qavg >> 1))
+                        return p->qavg - us_idle;
+                else
+                        return p->qavg >> 1;
+        }
+}
+
+static inline unsigned long red_calc_qavg_no_idle_time(struct red_parms *p,
+                                                       unsigned int backlog)
+{
+        /*
+         * NOTE: p->qavg is fixed point number with point at Wlog.
+         * The formula below is equvalent to floating point
+         * version:
+         *
+         *      qavg = qavg*(1-W) + backlog*W;
+         *
+         * --ANK (980924)
+         */
+        return p->qavg + (backlog - (p->qavg >> p->Wlog));
+}
+
+static inline unsigned long red_calc_qavg(struct red_parms *p,
+                                          unsigned int backlog)
+{
+        if (!red_is_idling(p))
+                return red_calc_qavg_no_idle_time(p, backlog);
+        else
+                return red_calc_qavg_from_idle_time(p);
+}
+
+static inline u32 red_random(struct red_parms *p)
+{
+        return net_random() & p->Rmask;
+}
+
+static inline int red_mark_probability(struct red_parms *p, unsigned long qavg)
+{
+        /* The formula used below causes questions.
+
+           OK. qR is random number in the interval 0..Rmask
+           i.e. 0..(2^Plog). If we used floating point
+           arithmetics, it would be: (2^Plog)*rnd_num,
+           where rnd_num is less 1.
+
+           Taking into account, that qavg have fixed
+           point at Wlog, and Plog is related to max_P by
+           max_P = (qth_max-qth_min)/2^Plog; two lines
+           below have the following floating point equivalent:
+
+           max_P*(qavg - qth_min)/(qth_max-qth_min) < rnd/qcount
+
+           Any questions? --ANK (980924)
+         */
+        return !(((qavg - p->qth_min) >> p->Wlog) * p->qcount < p->qR);
+}
+
+enum {
+        RED_BELOW_MIN_THRESH,
+        RED_BETWEEN_TRESH,
+        RED_ABOVE_MAX_TRESH,
+};
+
+static inline int red_cmp_thresh(struct red_parms *p, unsigned long qavg)
+{
+        if (qavg < p->qth_min)
+                return RED_BELOW_MIN_THRESH;
+        else if (qavg >= p->qth_max)
+                return RED_ABOVE_MAX_TRESH;
+        else
+                return RED_BETWEEN_TRESH;
+}
+
+enum {
+        RED_DONT_MARK,
+        RED_PROB_MARK,
+        RED_HARD_MARK,
+};
+
+static inline int red_action(struct red_parms *p, unsigned long qavg)
+{
+        switch (red_cmp_thresh(p, qavg)) {
+                case RED_BELOW_MIN_THRESH:
+                        p->qcount = -1;
+                        return RED_DONT_MARK;
+
+                case RED_BETWEEN_TRESH:
+                        if (++p->qcount) {
+                                if (red_mark_probability(p, qavg)) {
+                                        p->qcount = 0;
+                                        p->qR = red_random(p);
+                                        return RED_PROB_MARK;
+                                }
+                        } else
+                                p->qR = red_random(p);
+
+                        return RED_DONT_MARK;
+
+                case RED_ABOVE_MAX_TRESH:
+                        p->qcount = -1;
+                        return RED_HARD_MARK;
+        }
+
+        BUG();
+        return RED_DONT_MARK;
+}
+
+#endif
diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c
index 25c171c32715..29a2dd9f3029 100644
--- a/net/sched/sch_gred.c
+++ b/net/sched/sch_gred.c
@@ -15,247 +15,281 @@
  *                       from Ren Liu
  *                     - More error checks
  *
- *
- *
- *  For all the glorious comments look at Alexey's sch_red.c
+ *  For all the glorious comments look at include/net/red.h
  */
 
 #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/sched.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>
+#include <net/red.h>
 
-#if 1 /* control */
-#define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
-#else
-#define DPRINTK(format,args...)
-#endif
-
-#if 0 /* data */
-#define D2PRINTK(format,args...) printk(KERN_DEBUG format,##args)
-#else
-#define D2PRINTK(format,args...)
-#endif
+#define GRED_DEF_PRIO (MAX_DPs / 2)
+#define GRED_VQ_MASK (MAX_DPs - 1)
 
 struct gred_sched_data;
 struct gred_sched;
 
 struct gred_sched_data
 {
-/* Parameters */
         u32             limit;          /* HARD maximal queue length    */
-        u32             qth_min;        /* Min average length threshold: A scaled */
-        u32             qth_max;        /* Max average length threshold: A scaled */
         u32             DP;             /* the drop pramaters */
-        char            Wlog;           /* log(W)               */
-        char            Plog;           /* random number bits   */
-        u32             Scell_max;
-        u32             Rmask;
         u32             bytesin;        /* bytes seen on virtualQ so far*/
         u32             packetsin;      /* packets seen on virtualQ so far*/
         u32             backlog;        /* bytes on the virtualQ */
-        u32             forced; /* packets dropped for exceeding limits */
-        u32             early;  /* packets dropped as a warning */
-        u32             other;  /* packets dropped by invoking drop() */
-        u32             pdrop;  /* packets dropped because we exceeded physical queue limits */
-        char            Scell_log;
-        u8              Stab[256];
-        u8              prio;        /* the prio of this vq */
-
-/* Variables */
-        unsigned long   qave;           /* Average queue length: A scaled */
-        int             qcount;         /* Packets since last random number generation */
-        u32             qR;             /* Cached random number */
-
-        psched_time_t   qidlestart;     /* Start of idle period */
+        u8              prio;           /* the prio of this vq */
+
+        struct red_parms parms;
+        struct red_stats stats;
+};
+
+enum {
+        GRED_WRED_MODE = 1,
+        GRED_RIO_MODE,
 };
 
 struct gred_sched
 {
         struct gred_sched_data *tab[MAX_DPs];
-        u32             DPs;   
-        u32             def; 
-        u8              initd; 
-        u8              grio; 
-        u8              eqp; 
+        unsigned long   flags;
+        u32             red_flags;
+        u32             DPs;
+        u32             def;
+        struct red_parms wred_set;
 };
 
-static int
-gred_enqueue(struct sk_buff *skb, struct Qdisc* sch)
+static inline int gred_wred_mode(struct gred_sched *table)
 {
-        psched_time_t now;
-        struct gred_sched_data *q=NULL;
-        struct gred_sched *t= qdisc_priv(sch);
-        unsigned long   qave=0; 
-        int i=0;
+        return test_bit(GRED_WRED_MODE, &table->flags);
+}
+
+static inline void gred_enable_wred_mode(struct gred_sched *table)
+{
+        __set_bit(GRED_WRED_MODE, &table->flags);
+}
+
+static inline void gred_disable_wred_mode(struct gred_sched *table)
+{
+        __clear_bit(GRED_WRED_MODE, &table->flags);
+}
+
+static inline int gred_rio_mode(struct gred_sched *table)
+{
+        return test_bit(GRED_RIO_MODE, &table->flags);
+}
+
+static inline void gred_enable_rio_mode(struct gred_sched *table)
+{
+        __set_bit(GRED_RIO_MODE, &table->flags);
+}
+
+static inline void gred_disable_rio_mode(struct gred_sched *table)
+{
+        __clear_bit(GRED_RIO_MODE, &table->flags);
+}
+
+static inline int gred_wred_mode_check(struct Qdisc *sch)
+{
+        struct gred_sched *table = qdisc_priv(sch);
+        int i;
 
-        if (!t->initd && skb_queue_len(&sch->q) < (sch->dev->tx_queue_len ? : 1)) {
-                D2PRINTK("NO GRED Queues setup yet! Enqueued anyway\n");
-                goto do_enqueue;
+        /* Really ugly O(n^2) but shouldn't be necessary too frequent. */
+        for (i = 0; i < table->DPs; i++) {
+                struct gred_sched_data *q = table->tab[i];
+                int n;
+
+                if (q == NULL)
+                        continue;
+
+                for (n = 0; n < table->DPs; n++)
+                        if (table->tab[n] && table->tab[n] != q &&
+                            table->tab[n]->prio == q->prio)
+                                return 1;
         }
 
+        return 0;
+}
+
+static inline unsigned int gred_backlog(struct gred_sched *table,
+                                        struct gred_sched_data *q,
+                                        struct Qdisc *sch)
+{
+        if (gred_wred_mode(table))
+                return sch->qstats.backlog;
+        else
+                return q->backlog;
+}
+
+static inline u16 tc_index_to_dp(struct sk_buff *skb)
+{
+        return skb->tc_index & GRED_VQ_MASK;
+}
+
+static inline void gred_load_wred_set(struct gred_sched *table,
+                                      struct gred_sched_data *q)
+{
+        q->parms.qavg = table->wred_set.qavg;
+        q->parms.qidlestart = table->wred_set.qidlestart;
+}
+
+static inline void gred_store_wred_set(struct gred_sched *table,
+                                       struct gred_sched_data *q)
+{
+        table->wred_set.qavg = q->parms.qavg;
+}
+
+static inline int gred_use_ecn(struct gred_sched *t)
+{
+        return t->red_flags & TC_RED_ECN;
+}
 
-        if ( ((skb->tc_index&0xf) > (t->DPs -1)) || !(q=t->tab[skb->tc_index&0xf])) {
-                printk("GRED: setting to default (%d)\n ",t->def);
-                if (!(q=t->tab[t->def])) {
-                        DPRINTK("GRED: setting to default FAILED! dropping!! "
-                            "(%d)\n ", t->def);
-                        goto drop;
+static inline int gred_use_harddrop(struct gred_sched *t)
+{
+        return t->red_flags & TC_RED_HARDDROP;
+}
+
+static int gred_enqueue(struct sk_buff *skb, struct Qdisc* sch)
+{
+        struct gred_sched_data *q=NULL;
+        struct gred_sched *t= qdisc_priv(sch);
+        unsigned long qavg = 0;
+        u16 dp = tc_index_to_dp(skb);
+
+        if (dp >= t->DPs  || (q = t->tab[dp]) == NULL) {
+                dp = t->def;
+
+                if ((q = t->tab[dp]) == NULL) {
+                        /* Pass through packets not assigned to a DP
+                         * if no default DP has been configured. This
+                         * allows for DP flows to be left untouched.
+                         */
+                        if (skb_queue_len(&sch->q) < sch->dev->tx_queue_len)
+                                return qdisc_enqueue_tail(skb, sch);
+                        else
+                                goto drop;
                 }
+
                 /* fix tc_index? --could be controvesial but needed for
                    requeueing */
-                skb->tc_index=(skb->tc_index&0xfffffff0) | t->def;
+                skb->tc_index = (skb->tc_index & ~GRED_VQ_MASK) | dp;
         }
 
-        D2PRINTK("gred_enqueue virtualQ 0x%x classid %x backlog %d "
-            "general backlog %d\n",skb->tc_index&0xf,sch->handle,q->backlog,
-            sch->qstats.backlog);
-        /* sum up all the qaves of prios <= to ours to get the new qave*/
-        if (!t->eqp && t->grio) {
-                for (i=0;i<t->DPs;i++) {
-                        if ((!t->tab[i]) || (i==q->DP)) 
-                                continue; 
-                                
-                        if ((t->tab[i]->prio < q->prio) && (PSCHED_IS_PASTPERFECT(t->tab[i]->qidlestart)))
-                                qave +=t->tab[i]->qave;
+        /* sum up all the qaves of prios <= to ours to get the new qave */
+        if (!gred_wred_mode(t) && gred_rio_mode(t)) {
+                int i;
+
+                for (i = 0; i < t->DPs; i++) {
+                        if (t->tab[i] && t->tab[i]->prio < q->prio &&
+                            !red_is_idling(&t->tab[i]->parms))
+                                qavg +=t->tab[i]->parms.qavg;
                 }
-                        
+
         }
 
         q->packetsin++;
-        q->bytesin+=skb->len;
+        q->bytesin += skb->len;
 
-        if (t->eqp && t->grio) {
-                qave=0;
-                q->qave=t->tab[t->def]->qave;
-                q->qidlestart=t->tab[t->def]->qidlestart;
-        }
+        if (gred_wred_mode(t))
+                gred_load_wred_set(t, q);
 
-        if (!PSCHED_IS_PASTPERFECT(q->qidlestart)) {
-                long us_idle;
-                PSCHED_GET_TIME(now);
-                us_idle = PSCHED_TDIFF_SAFE(now, q->qidlestart, q->Scell_max);
-                PSCHED_SET_PASTPERFECT(q->qidlestart);
+        q->parms.qavg = red_calc_qavg(&q->parms, gred_backlog(t, q, sch));
 
-                q->qave >>= q->Stab[(us_idle>>q->Scell_log)&0xFF];
-        } else {
-                if (t->eqp) {
-                        q->qave += sch->qstats.backlog - (q->qave >> q->Wlog);
-                } else {
-                        q->qave += q->backlog - (q->qave >> q->Wlog);
-                }
+        if (red_is_idling(&q->parms))
+                red_end_of_idle_period(&q->parms);
 
-        }
-        
-
-        if (t->eqp && t->grio) 
-                t->tab[t->def]->qave=q->qave;
-
-        if ((q->qave+qave) < q->qth_min) {
-                q->qcount = -1;
-enqueue:
-                if (q->backlog + skb->len <= q->limit) {
-                        q->backlog += skb->len;
-do_enqueue:
-                        __skb_queue_tail(&sch->q, skb);
-                        sch->qstats.backlog += skb->len;
-                        sch->bstats.bytes += skb->len;
-                        sch->bstats.packets++;
-                        return 0;
-                } else {
-                        q->pdrop++;
-                }
+        if (gred_wred_mode(t))
+                gred_store_wred_set(t, q);
 
-drop:
-                kfree_skb(skb);
-                sch->qstats.drops++;
-                return NET_XMIT_DROP;
-        }
-        if ((q->qave+qave) >= q->qth_max) {
-                q->qcount = -1;
-                sch->qstats.overlimits++;
-                q->forced++;
-                goto drop;
+        switch (red_action(&q->parms, q->parms.qavg + qavg)) {
+                case RED_DONT_MARK:
+                        break;
+
+                case RED_PROB_MARK:
+                        sch->qstats.overlimits++;
+                        if (!gred_use_ecn(t) || !INET_ECN_set_ce(skb)) {
+                                q->stats.prob_drop++;
+                                goto congestion_drop;
+                        }
+
+                        q->stats.prob_mark++;
+                        break;
+
+                case RED_HARD_MARK:
+                        sch->qstats.overlimits++;
+                        if (gred_use_harddrop(t) || !gred_use_ecn(t) ||
+                            !INET_ECN_set_ce(skb)) {
+                                q->stats.forced_drop++;
+                                goto congestion_drop;
+                        }
+                        q->stats.forced_mark++;
+                        break;
         }
-        if (++q->qcount) {
-                if ((((qave+q->qave) - q->qth_min)>>q->Wlog)*q->qcount < q->qR)
-                        goto enqueue;
-                q->qcount = 0;
-                q->qR = net_random()&q->Rmask;
-                sch->qstats.overlimits++;
-                q->early++;
-                goto drop;
+
+        if (q->backlog + skb->len <= q->limit) {
+                q->backlog += skb->len;
+                return qdisc_enqueue_tail(skb, sch);
         }
-        q->qR = net_random()&q->Rmask;
-        goto enqueue;
+
+        q->stats.pdrop++;
+drop:
+        return qdisc_drop(skb, sch);
+
+congestion_drop:
+        qdisc_drop(skb, sch);
+        return NET_XMIT_CN;
 }
 
-static int
-gred_requeue(struct sk_buff *skb, struct Qdisc* sch)
+static int gred_requeue(struct sk_buff *skb, struct Qdisc* sch)
 {
+        struct gred_sched *t = qdisc_priv(sch);
         struct gred_sched_data *q;
-        struct gred_sched *t= qdisc_priv(sch);
-        q= t->tab[(skb->tc_index&0xf)];
-/* error checking here -- probably unnecessary */
-        PSCHED_SET_PASTPERFECT(q->qidlestart);
-
-        __skb_queue_head(&sch->q, skb);
-        sch->qstats.backlog += skb->len;
-        sch->qstats.requeues++;
-        q->backlog += skb->len;
-        return 0;
+        u16 dp = tc_index_to_dp(skb);
+
+        if (dp >= t->DPs || (q = t->tab[dp]) == NULL) {
+                if (net_ratelimit())
+                        printk(KERN_WARNING "GRED: Unable to relocate VQ 0x%x "
+                               "for requeue, screwing up backlog.\n",
+                               tc_index_to_dp(skb));
+        } else {
+                if (red_is_idling(&q->parms))
+                        red_end_of_idle_period(&q->parms);
+                q->backlog += skb->len;
+        }
+
+        return qdisc_requeue(skb, sch);
 }
 
-static struct sk_buff *
-gred_dequeue(struct Qdisc* sch)
+static struct sk_buff *gred_dequeue(struct Qdisc* sch)
 {
         struct sk_buff *skb;
-        struct gred_sched_data *q;
-        struct gred_sched *t= qdisc_priv(sch);
+        struct gred_sched *t = qdisc_priv(sch);
+
+        skb = qdisc_dequeue_head(sch);
 
-        skb = __skb_dequeue(&sch->q);
         if (skb) {
-                sch->qstats.backlog -= skb->len;
-                q= t->tab[(skb->tc_index&0xf)];
-                if (q) {
-                        q->backlog -= skb->len;
-                        if (!q->backlog && !t->eqp)
-                                PSCHED_GET_TIME(q->qidlestart);
+                struct gred_sched_data *q;
+                u16 dp = tc_index_to_dp(skb);
+
+                if (dp >= t->DPs || (q = t->tab[dp]) == NULL) {
+                        if (net_ratelimit())
+                                printk(KERN_WARNING "GRED: Unable to relocate "
+                                       "VQ 0x%x after dequeue, screwing up "
+                                       "backlog.\n", tc_index_to_dp(skb));
                 } else {
-                        D2PRINTK("gred_dequeue: skb has bad tcindex %x\n",skb->tc_index&0xf); 
+                        q->backlog -= skb->len;
+
+                        if (!q->backlog && !gred_wred_mode(t))
+                                red_start_of_idle_period(&q->parms);
                 }
+
                 return skb;
         }
 
-        if (t->eqp) {
-                        q= t->tab[t->def];
-                        if (!q) 
-                                D2PRINTK("no default VQ set: Results will be "
-                                       "screwed up\n");
-                        else
-                                PSCHED_GET_TIME(q->qidlestart);
-        }
+        if (gred_wred_mode(t) && !red_is_idling(&t->wred_set))
+                red_start_of_idle_period(&t->wred_set);
 
         return NULL;
 }
@@ -263,36 +297,34 @@ gred_dequeue(struct Qdisc* sch)
 static unsigned int gred_drop(struct Qdisc* sch)
 {
         struct sk_buff *skb;
+        struct gred_sched *t = qdisc_priv(sch);
 
-        struct gred_sched_data *q;
-        struct gred_sched *t= qdisc_priv(sch);
-
-        skb = __skb_dequeue_tail(&sch->q);
+        skb = qdisc_dequeue_tail(sch);
         if (skb) {
                 unsigned int len = skb->len;
-                sch->qstats.backlog -= len;
-                sch->qstats.drops++;
-                q= t->tab[(skb->tc_index&0xf)];
-                if (q) {
-                        q->backlog -= len;
-                        q->other++;
-                        if (!q->backlog && !t->eqp)
-                                PSCHED_GET_TIME(q->qidlestart);
+                struct gred_sched_data *q;
+                u16 dp = tc_index_to_dp(skb);
+
+                if (dp >= t->DPs || (q = t->tab[dp]) == NULL) {
+                        if (net_ratelimit())
+                                printk(KERN_WARNING "GRED: Unable to relocate "
+                                       "VQ 0x%x while dropping, screwing up "
+                                       "backlog.\n", tc_index_to_dp(skb));
                 } else {
-                        D2PRINTK("gred_dequeue: skb has bad tcindex %x\n",skb->tc_index&0xf); 
+                        q->backlog -= len;
+                        q->stats.other++;
+
+                        if (!q->backlog && !gred_wred_mode(t))
+                                red_start_of_idle_period(&q->parms);
                 }
 
-                kfree_skb(skb);
+                qdisc_drop(skb, sch);
                 return len;
         }
 
-        q=t->tab[t->def];
-        if (!q) {
-                D2PRINTK("no default VQ set: Results might be screwed up\n");
-                return 0;
-        }
+        if (gred_wred_mode(t) && !red_is_idling(&t->wred_set))
+                red_start_of_idle_period(&t->wred_set);
 
-        PSCHED_GET_TIME(q->qidlestart);
         return 0;
 
 }
@@ -300,293 +332,241 @@ static unsigned int gred_drop(struct Qdisc* sch)
 static void gred_reset(struct Qdisc* sch)
 {
         int i;
-        struct gred_sched_data *q;
-        struct gred_sched *t= qdisc_priv(sch);
+        struct gred_sched *t = qdisc_priv(sch);
+
+        qdisc_reset_queue(sch);
 
-        __skb_queue_purge(&sch->q);
+        for (i = 0; i < t->DPs; i++) {
+                struct gred_sched_data *q = t->tab[i];
 
-        sch->qstats.backlog = 0;
+                if (!q)
+                        continue;
 
-        for (i=0;i<t->DPs;i++) {
-                q= t->tab[i];
-                if (!q) 
-                        continue; 
-                PSCHED_SET_PASTPERFECT(q->qidlestart);
-                q->qave = 0;
-                q->qcount = -1;
+                red_restart(&q->parms);
                 q->backlog = 0;
-                q->other=0;
-                q->forced=0;
-                q->pdrop=0;
-                q->early=0;
         }
 }
 
-static int gred_change(struct Qdisc *sch, struct rtattr *opt)
+static inline void gred_destroy_vq(struct gred_sched_data *q)
+{
+        kfree(q);
+}
+
+static inline int gred_change_table_def(struct Qdisc *sch, struct rtattr *dps)
 {
         struct gred_sched *table = qdisc_priv(sch);
-        struct gred_sched_data *q;
-        struct tc_gred_qopt *ctl;
         struct tc_gred_sopt *sopt;
-        struct rtattr *tb[TCA_GRED_STAB];
-        struct rtattr *tb2[TCA_GRED_DPS];
         int i;
 
-        if (opt == NULL || rtattr_parse_nested(tb, TCA_GRED_STAB, opt))
+        if (dps == NULL || RTA_PAYLOAD(dps) < sizeof(*sopt))
                 return -EINVAL;
 
-        if (tb[TCA_GRED_PARMS-1] == 0 && tb[TCA_GRED_STAB-1] == 0) {
-                rtattr_parse_nested(tb2, TCA_GRED_DPS, opt);
+        sopt = RTA_DATA(dps);
+
+        if (sopt->DPs > MAX_DPs || sopt->DPs == 0 || sopt->def_DP >= sopt->DPs)
+                return -EINVAL;
 
-            if (tb2[TCA_GRED_DPS-1] == 0) 
-                        return -EINVAL;
+        sch_tree_lock(sch);
+        table->DPs = sopt->DPs;
+        table->def = sopt->def_DP;
+        table->red_flags = sopt->flags;
+
+        /*
+         * Every entry point to GRED is synchronized with the above code
+         * and the DP is checked against DPs, i.e. shadowed VQs can no
+         * longer be found so we can unlock right here.
+         */
+        sch_tree_unlock(sch);
+
+        if (sopt->grio) {
+                gred_enable_rio_mode(table);
+                gred_disable_wred_mode(table);
+                if (gred_wred_mode_check(sch))
+                        gred_enable_wred_mode(table);
+        } else {
+                gred_disable_rio_mode(table);
+                gred_disable_wred_mode(table);
+        }
 
-                sopt = RTA_DATA(tb2[TCA_GRED_DPS-1]);
-                table->DPs=sopt->DPs;   
-                table->def=sopt->def_DP; 
-                table->grio=sopt->grio; 
-                table->initd=0;
-                /* probably need to clear all the table DP entries as well */
-                return 0;
-            }
+        for (i = table->DPs; i < MAX_DPs; i++) {
+                if (table->tab[i]) {
+                        printk(KERN_WARNING "GRED: Warning: Destroying "
+                               "shadowed VQ 0x%x\n", i);
+                        gred_destroy_vq(table->tab[i]);
+                        table->tab[i] = NULL;
+                }
+        }
 
+        return 0;
+}
 
-        if (!table->DPs || tb[TCA_GRED_PARMS-1] == 0 || tb[TCA_GRED_STAB-1] == 0 ||
-                RTA_PAYLOAD(tb[TCA_GRED_PARMS-1]) < sizeof(*ctl) ||
-                RTA_PAYLOAD(tb[TCA_GRED_STAB-1]) < 256)
-                        return -EINVAL;
+static inline int gred_change_vq(struct Qdisc *sch, int dp,
+                                 struct tc_gred_qopt *ctl, int prio, u8 *stab)
+{
+        struct gred_sched *table = qdisc_priv(sch);
+        struct gred_sched_data *q;
 
-        ctl = RTA_DATA(tb[TCA_GRED_PARMS-1]);
-        if (ctl->DP > MAX_DPs-1 ) {
-                /* misbehaving is punished! Put in the default drop probability */
-                DPRINTK("\nGRED: DP %u not in  the proper range fixed. New DP "
-                        "set to default at %d\n",ctl->DP,table->def);
-                ctl->DP=table->def;
-        }
-        
-        if (table->tab[ctl->DP] == NULL) {
-                table->tab[ctl->DP]=kmalloc(sizeof(struct gred_sched_data),
-                                            GFP_KERNEL);
-                if (NULL == table->tab[ctl->DP])
+        if (table->tab[dp] == NULL) {
+                table->tab[dp] = kmalloc(sizeof(*q), GFP_KERNEL);
+                if (table->tab[dp] == NULL)
                         return -ENOMEM;
-                memset(table->tab[ctl->DP], 0, (sizeof(struct gred_sched_data)));
-        }
-        q= table->tab[ctl->DP]; 
-
-        if (table->grio) {
-                if (ctl->prio <=0) {
-                        if (table->def && table->tab[table->def]) {
-                                DPRINTK("\nGRED: DP %u does not have a prio"
-                                        "setting default to %d\n",ctl->DP,
-                                        table->tab[table->def]->prio);
-                                q->prio=table->tab[table->def]->prio;
-                        } else { 
-                                DPRINTK("\nGRED: DP %u does not have a prio"
-                                        " setting default to 8\n",ctl->DP);
-                                q->prio=8;
-                        }
-                } else {
-                        q->prio=ctl->prio;
-                }
-        } else {
-                q->prio=8;
+                memset(table->tab[dp], 0, sizeof(*q));
         }
 
-
-        q->DP=ctl->DP;
-        q->Wlog = ctl->Wlog;
-        q->Plog = ctl->Plog;
+        q = table->tab[dp];
+        q->DP = dp;
+        q->prio = prio;
         q->limit = ctl->limit;
-        q->Scell_log = ctl->Scell_log;
-        q->Rmask = ctl->Plog < 32 ? ((1<<ctl->Plog) - 1) : ~0UL;
-        q->Scell_max = (255<<q->Scell_log);
-        q->qth_min = ctl->qth_min<<ctl->Wlog;
-        q->qth_max = ctl->qth_max<<ctl->Wlog;
-        q->qave=0;
-        q->backlog=0;
-        q->qcount = -1;
-        q->other=0;
-        q->forced=0;
-        q->pdrop=0;
-        q->early=0;
-
-        PSCHED_SET_PASTPERFECT(q->qidlestart);
-        memcpy(q->Stab, RTA_DATA(tb[TCA_GRED_STAB-1]), 256);
-
-        if ( table->initd && table->grio) {
-        /* this looks ugly but it's not in the fast path */
-                for (i=0;i<table->DPs;i++) {
-                        if ((!table->tab[i]) || (i==q->DP) )    
-                                continue; 
-                        if (table->tab[i]->prio == q->prio ){
-                                /* WRED mode detected */
-                                table->eqp=1;
-                                break;
-                        }
-                }
-        }
 
-        if (!table->initd) {
-                table->initd=1;
-                /* 
-                the first entry also goes into the default until
-                over-written 
-                */
-
-                if (table->tab[table->def] == NULL) {
-                        table->tab[table->def]=
-                                kmalloc(sizeof(struct gred_sched_data), GFP_KERNEL);
-                        if (NULL == table->tab[table->def])
-                                return -ENOMEM;
-
-                        memset(table->tab[table->def], 0,
-                               (sizeof(struct gred_sched_data)));
-                }
-                q= table->tab[table->def]; 
-                q->DP=table->def;
-                q->Wlog = ctl->Wlog;
-                q->Plog = ctl->Plog;
-                q->limit = ctl->limit;
-                q->Scell_log = ctl->Scell_log;
-                q->Rmask = ctl->Plog < 32 ? ((1<<ctl->Plog) - 1) : ~0UL;
-                q->Scell_max = (255<<q->Scell_log);
-                q->qth_min = ctl->qth_min<<ctl->Wlog;
-                q->qth_max = ctl->qth_max<<ctl->Wlog;
-
-                if (table->grio)
-                        q->prio=table->tab[ctl->DP]->prio;
-                else
-                        q->prio=8;
-
-                q->qcount = -1;
-                PSCHED_SET_PASTPERFECT(q->qidlestart);
-                memcpy(q->Stab, RTA_DATA(tb[TCA_GRED_STAB-1]), 256);
-        }
-        return 0;
+        if (q->backlog == 0)
+                red_end_of_idle_period(&q->parms);
 
+        red_set_parms(&q->parms,
+                      ctl->qth_min, ctl->qth_max, ctl->Wlog, ctl->Plog,
+                      ctl->Scell_log, stab);
+
+        return 0;
 }
 
-static int gred_init(struct Qdisc *sch, struct rtattr *opt)
+static int gred_change(struct Qdisc *sch, struct rtattr *opt)
 {
         struct gred_sched *table = qdisc_priv(sch);
-        struct tc_gred_sopt *sopt;
-        struct rtattr *tb[TCA_GRED_STAB];
-        struct rtattr *tb2[TCA_GRED_DPS];
+        struct tc_gred_qopt *ctl;
+        struct rtattr *tb[TCA_GRED_MAX];
+        int err = -EINVAL, prio = GRED_DEF_PRIO;
+        u8 *stab;
 
-        if (opt == NULL || rtattr_parse_nested(tb, TCA_GRED_STAB, opt))
+        if (opt == NULL || rtattr_parse_nested(tb, TCA_GRED_MAX, opt))
                 return -EINVAL;
 
-        if (tb[TCA_GRED_PARMS-1] == 0 && tb[TCA_GRED_STAB-1] == 0) {
-                rtattr_parse_nested(tb2, TCA_GRED_DPS, opt);
+        if (tb[TCA_GRED_PARMS-1] == NULL && tb[TCA_GRED_STAB-1] == NULL)
+                return gred_change_table_def(sch, opt);
+
+        if (tb[TCA_GRED_PARMS-1] == NULL ||
+            RTA_PAYLOAD(tb[TCA_GRED_PARMS-1]) < sizeof(*ctl) ||
+            tb[TCA_GRED_STAB-1] == NULL ||
+            RTA_PAYLOAD(tb[TCA_GRED_STAB-1]) < 256)
+                return -EINVAL;
+
+        ctl = RTA_DATA(tb[TCA_GRED_PARMS-1]);
+        stab = RTA_DATA(tb[TCA_GRED_STAB-1]);
+
+        if (ctl->DP >= table->DPs)
+                goto errout;
 
-            if (tb2[TCA_GRED_DPS-1] == 0) 
-                        return -EINVAL;
+        if (gred_rio_mode(table)) {
+                if (ctl->prio == 0) {
+                        int def_prio = GRED_DEF_PRIO;
 
-                sopt = RTA_DATA(tb2[TCA_GRED_DPS-1]);
-                table->DPs=sopt->DPs;   
-                table->def=sopt->def_DP; 
-                table->grio=sopt->grio; 
-                table->initd=0;
-                return 0;
+                        if (table->tab[table->def])
+                                def_prio = table->tab[table->def]->prio;
+
+                        printk(KERN_DEBUG "GRED: DP %u does not have a prio "
+                               "setting default to %d\n", ctl->DP, def_prio);
+
+                        prio = def_prio;
+                } else
+                        prio = ctl->prio;
+        }
+
+        sch_tree_lock(sch);
+
+        err = gred_change_vq(sch, ctl->DP, ctl, prio, stab);
+        if (err < 0)
+                goto errout_locked;
+
+        if (gred_rio_mode(table)) {
+                gred_disable_wred_mode(table);
+                if (gred_wred_mode_check(sch))
+                        gred_enable_wred_mode(table);
         }
 
-        DPRINTK("\n GRED_INIT error!\n");
-        return -EINVAL;
+        err = 0;
+
+errout_locked:
+        sch_tree_unlock(sch);
+errout:
+        return err;
 }
 
-static int gred_dump(struct Qdisc *sch, struct sk_buff *skb)
+static int gred_init(struct Qdisc *sch, struct rtattr *opt)
 {
-        unsigned long qave;
-        struct rtattr *rta;
-        struct tc_gred_qopt *opt = NULL ;
-        struct tc_gred_qopt *dst;
-        struct gred_sched *table = qdisc_priv(sch);
-        struct gred_sched_data *q;
-        int i;
-        unsigned char    *b = skb->tail;
+        struct rtattr *tb[TCA_GRED_MAX];
 
-        rta = (struct rtattr*)b;
-        RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
+        if (opt == NULL || rtattr_parse_nested(tb, TCA_GRED_MAX, opt))
+                return -EINVAL;
 
-        opt=kmalloc(sizeof(struct tc_gred_qopt)*MAX_DPs, GFP_KERNEL);
+        if (tb[TCA_GRED_PARMS-1] || tb[TCA_GRED_STAB-1])
+                return -EINVAL;
 
-        if (opt  == NULL) {
-                DPRINTK("gred_dump:failed to malloc for %Zd\n",
-                    sizeof(struct tc_gred_qopt)*MAX_DPs);
-                goto rtattr_failure;
-        }
+        return gred_change_table_def(sch, tb[TCA_GRED_DPS-1]);
+}
 
-        memset(opt, 0, (sizeof(struct tc_gred_qopt))*table->DPs);
+static int gred_dump(struct Qdisc *sch, struct sk_buff *skb)
+{
+        struct gred_sched *table = qdisc_priv(sch);
+        struct rtattr *parms, *opts = NULL;
+        int i;
+        struct tc_gred_sopt sopt = {
+                .DPs    = table->DPs,
+                .def_DP = table->def,
+                .grio   = gred_rio_mode(table),
+                .flags  = table->red_flags,
+        };
 
-        if (!table->initd) {
-                DPRINTK("NO GRED Queues setup!\n");
-        }
+        opts = RTA_NEST(skb, TCA_OPTIONS);
+        RTA_PUT(skb, TCA_GRED_DPS, sizeof(sopt), &sopt);
+        parms = RTA_NEST(skb, TCA_GRED_PARMS);
+
+        for (i = 0; i < MAX_DPs; i++) {
+                struct gred_sched_data *q = table->tab[i];
+                struct tc_gred_qopt opt;
 
-        for (i=0;i<MAX_DPs;i++) {
-                dst= &opt[i]; 
-                q= table->tab[i]; 
+                memset(&opt, 0, sizeof(opt));
 
                 if (!q) {
                         /* hack -- fix at some point with proper message
                            This is how we indicate to tc that there is no VQ
                            at this DP */
 
-                        dst->DP=MAX_DPs+i;
-                        continue;
+                        opt.DP = MAX_DPs + i;
+                        goto append_opt;
                 }
 
-                dst->limit=q->limit;
-                dst->qth_min=q->qth_min>>q->Wlog;
-                dst->qth_max=q->qth_max>>q->Wlog;
-                dst->DP=q->DP;
-                dst->backlog=q->backlog;
-                if (q->qave) {
-                        if (table->eqp && table->grio) {
-                                q->qidlestart=table->tab[table->def]->qidlestart;
-                                q->qave=table->tab[table->def]->qave;
-                        }
-                        if (!PSCHED_IS_PASTPERFECT(q->qidlestart)) {
-                                long idle;
-                                psched_time_t now;
-                                PSCHED_GET_TIME(now);
-                                idle = PSCHED_TDIFF_SAFE(now, q->qidlestart, q->Scell_max);
-                                qave  = q->qave >> q->Stab[(idle>>q->Scell_log)&0xFF];
-                                dst->qave = qave >> q->Wlog;
-
-                        } else {
-                                dst->qave = q->qave >> q->Wlog;
-                        }
-                } else {
-                        dst->qave = 0;
+                opt.limit       = q->limit;
+                opt.DP          = q->DP;
+                opt.backlog     = q->backlog;
+                opt.prio        = q->prio;
+                opt.qth_min     = q->parms.qth_min >> q->parms.Wlog;
+                opt.qth_max     = q->parms.qth_max >> q->parms.Wlog;
+                opt.Wlog        = q->parms.Wlog;
+                opt.Plog        = q->parms.Plog;
+                opt.Scell_log   = q->parms.Scell_log;
+                opt.other       = q->stats.other;
+                opt.early       = q->stats.prob_drop;
+                opt.forced      = q->stats.forced_drop;
+                opt.pdrop       = q->stats.pdrop;
+                opt.packets     = q->packetsin;
+                opt.bytesin     = q->bytesin;
+
+                if (gred_wred_mode(table)) {
+                        q->parms.qidlestart =
+                                table->tab[table->def]->parms.qidlestart;
+                        q->parms.qavg = table->tab[table->def]->parms.qavg;
                 }
-                
-
-                dst->Wlog = q->Wlog;
-                dst->Plog = q->Plog;
-                dst->Scell_log = q->Scell_log;
-                dst->other = q->other;
-                dst->forced = q->forced;
-                dst->early = q->early;
-                dst->pdrop = q->pdrop;
-                dst->prio = q->prio;
-                dst->packets=q->packetsin;
-                dst->bytesin=q->bytesin;
+
+                opt.qave = red_calc_qavg(&q->parms, q->parms.qavg);
+
+append_opt:
+                RTA_APPEND(skb, sizeof(opt), &opt);
         }
 
-        RTA_PUT(skb, TCA_GRED_PARMS, sizeof(struct tc_gred_qopt)*MAX_DPs, opt);
-        rta->rta_len = skb->tail - b;
+        RTA_NEST_END(skb, parms);
 
-        kfree(opt);
-        return skb->len;
+        return RTA_NEST_END(skb, opts);
 
 rtattr_failure:
-        if (opt)
-                kfree(opt);
-        DPRINTK("gred_dump: FAILURE!!!!\n");
-
-/* also free the opt struct here */
-        skb_trim(skb, b - skb->data);
-        return -1;
+        return RTA_NEST_CANCEL(skb, opts);
 }
 
 static void gred_destroy(struct Qdisc *sch)
@@ -594,15 +574,13 @@ static void gred_destroy(struct Qdisc *sch)
         struct gred_sched *table = qdisc_priv(sch);
         int i;
 
-        for (i = 0;i < table->DPs; i++) {
+        for (i = 0; i < table->DPs; i++) {
                 if (table->tab[i])
-                        kfree(table->tab[i]);
+                        gred_destroy_vq(table->tab[i]);
         }
 }
 
 static struct Qdisc_ops gred_qdisc_ops = {
-        .next           =       NULL,
-        .cl_ops         =       NULL,
         .id             =       "gred",
         .priv_size      =       sizeof(struct gred_sched),
         .enqueue        =       gred_enqueue,
@@ -621,10 +599,13 @@ static int __init gred_module_init(void)
 {
         return register_qdisc(&gred_qdisc_ops);
 }
-static void __exit gred_module_exit(void) 
+
+static void __exit gred_module_exit(void)
 {
         unregister_qdisc(&gred_qdisc_ops);
 }
+
 module_init(gred_module_init)
 module_exit(gred_module_exit)
+
 MODULE_LICENSE("GPL");
diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c
index 7845d045eec4..dccfa44c2d71 100644
--- a/net/sched/sch_red.c
+++ b/net/sched/sch_red.c
@@ -9,76 +9,23 @@
  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  *
  * Changes:
- * J Hadi Salim <hadi@nortel.com> 980914:       computation fixes
+ * J Hadi Salim 980914: computation fixes
  * Alexey Makarenko <makar@phoenix.kharkov.ua> 990814: qave on idle link was calculated incorrectly.
- * J Hadi Salim <hadi@nortelnetworks.com> 980816:  ECN support  
+ * J Hadi Salim 980816:  ECN support
  */
 
 #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/sched.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>
 #include <net/inet_ecn.h>
-#include <net/dsfield.h>
+#include <net/red.h>
 
 
-/*      Random Early Detection (RED) algorithm.
-        =======================================
-
-        Source: Sally Floyd and Van Jacobson, "Random Early Detection Gateways
-        for Congestion Avoidance", 1993, IEEE/ACM Transactions on Networking.
-
-        This file codes a "divisionless" version of RED algorithm
-        as written down in Fig.17 of the paper.
-
-Short description.
-------------------
-
-        When a new packet arrives we calculate the average queue length:
-
-        avg = (1-W)*avg + W*current_queue_len,
-
-        W is the filter time constant (chosen as 2^(-Wlog)), it controls
-        the inertia of the algorithm. To allow larger bursts, W should be
-        decreased.
-
-        if (avg > th_max) -> packet marked (dropped).
-        if (avg < th_min) -> packet passes.
-        if (th_min < avg < th_max) we calculate probability:
-
-        Pb = max_P * (avg - th_min)/(th_max-th_min)
-
-        and mark (drop) packet with this probability.
-        Pb changes from 0 (at avg==th_min) to max_P (avg==th_max).
-        max_P should be small (not 1), usually 0.01..0.02 is good value.
-
-        max_P is chosen as a number, so that max_P/(th_max-th_min)
-        is a negative power of two in order arithmetics to contain
-        only shifts.
-
-
-        Parameters, settable by user:
+/*      Parameters, settable by user:
         -----------------------------
 
         limit           - bytes (must be > qth_max + burst)
@@ -89,243 +36,93 @@ Short description.
         arbitrarily high (well, less than ram size)
         Really, this limit will never be reached
         if RED works correctly.
-
-        qth_min         - bytes (should be < qth_max/2)
-        qth_max         - bytes (should be at least 2*qth_min and less limit)
-        Wlog            - bits (<32) log(1/W).
-        Plog            - bits (<32)
-
-        Plog is related to max_P by formula:
-
-        max_P = (qth_max-qth_min)/2^Plog;
-
-        F.e. if qth_max=128K and qth_min=32K, then Plog=22
-        corresponds to max_P=0.02
-
-        Scell_log
-        Stab
-
-        Lookup table for log((1-W)^(t/t_ave).
-
-
-NOTES:
-
-Upper bound on W.
------------------
-
-        If you want to allow bursts of L packets of size S,
-        you should choose W:
-
-        L + 1 - th_min/S < (1-(1-W)^L)/W
-
-        th_min/S = 32         th_min/S = 4
-                                               
-        log(W)  L
-        -1      33
-        -2      35
-        -3      39
-        -4      46
-        -5      57
-        -6      75
-        -7      101
-        -8      135
-        -9      190
-        etc.
  */
 
 struct red_sched_data
 {
-/* Parameters */
-        u32             limit;          /* HARD maximal queue length    */
-        u32             qth_min;        /* Min average length threshold: A scaled */
-        u32             qth_max;        /* Max average length threshold: A scaled */
-        u32             Rmask;
-        u32             Scell_max;
-        unsigned char   flags;
-        char            Wlog;           /* log(W)               */
-        char            Plog;           /* random number bits   */
-        char            Scell_log;
-        u8              Stab[256];
-
-/* Variables */
-        unsigned long   qave;           /* Average queue length: A scaled */
-        int             qcount;         /* Packets since last random number generation */
-        u32             qR;             /* Cached random number */
-
-        psched_time_t   qidlestart;     /* Start of idle period         */
-        struct tc_red_xstats st;
+        u32                     limit;          /* HARD maximal queue length */
+        unsigned char           flags;
+        struct red_parms        parms;
+        struct red_stats        stats;
 };
 
-static int red_ecn_mark(struct sk_buff *skb)
+static inline int red_use_ecn(struct red_sched_data *q)
 {
-        if (skb->nh.raw + 20 > skb->tail)
-                return 0;
-
-        switch (skb->protocol) {
-        case __constant_htons(ETH_P_IP):
-                if (INET_ECN_is_not_ect(skb->nh.iph->tos))
-                        return 0;
-                IP_ECN_set_ce(skb->nh.iph);
-                return 1;
-        case __constant_htons(ETH_P_IPV6):
-                if (INET_ECN_is_not_ect(ipv6_get_dsfield(skb->nh.ipv6h)))
-                        return 0;
-                IP6_ECN_set_ce(skb->nh.ipv6h);
-                return 1;
-        default:
-                return 0;
-        }
+        return q->flags & TC_RED_ECN;
 }
 
-static int
-red_enqueue(struct sk_buff *skb, struct Qdisc* sch)
+static inline int red_use_harddrop(struct red_sched_data *q)
+{
+        return q->flags & TC_RED_HARDDROP;
+}
+
+static int red_enqueue(struct sk_buff *skb, struct Qdisc* sch)
 {
         struct red_sched_data *q = qdisc_priv(sch);
 
-        psched_time_t now;
+        q->parms.qavg = red_calc_qavg(&q->parms, sch->qstats.backlog);
 
-        if (!PSCHED_IS_PASTPERFECT(q->qidlestart)) {
-                long us_idle;
-                int  shift;
+        if (red_is_idling(&q->parms))
+                red_end_of_idle_period(&q->parms);
 
-                PSCHED_GET_TIME(now);
-                us_idle = PSCHED_TDIFF_SAFE(now, q->qidlestart, q->Scell_max);
-                PSCHED_SET_PASTPERFECT(q->qidlestart);
+        switch (red_action(&q->parms, q->parms.qavg)) {
+                case RED_DONT_MARK:
+                        break;
 
-/*
-   The problem: ideally, average length queue recalcultion should
-   be done over constant clock intervals. This is too expensive, so that
-   the calculation is driven by outgoing packets.
-   When the queue is idle we have to model this clock by hand.
-
-   SF+VJ proposed to "generate" m = idletime/(average_pkt_size/bandwidth)
-   dummy packets as a burst after idle time, i.e.
-
-          q->qave *= (1-W)^m
-
-   This is an apparently overcomplicated solution (f.e. we have to precompute
-   a table to make this calculation in reasonable time)
-   I believe that a simpler model may be used here,
-   but it is field for experiments.
-*/
-                shift = q->Stab[us_idle>>q->Scell_log];
-
-                if (shift) {
-                        q->qave >>= shift;
-                } else {
-                        /* Approximate initial part of exponent
-                           with linear function:
-                           (1-W)^m ~= 1-mW + ...
-
-                           Seems, it is the best solution to
-                           problem of too coarce exponent tabulation.
-                         */
-
-                        us_idle = (q->qave * us_idle)>>q->Scell_log;
-                        if (us_idle < q->qave/2)
-                                q->qave -= us_idle;
-                        else
-                                q->qave >>= 1;
-                }
-        } else {
-                q->qave += sch->qstats.backlog - (q->qave >> q->Wlog);
-                /* NOTE:
-                   q->qave is fixed point number with point at Wlog.
-                   The formulae above is equvalent to floating point
-                   version:
-
-                   qave = qave*(1-W) + sch->qstats.backlog*W;
-                                                           --ANK (980924)
-                 */
-        }
+                case RED_PROB_MARK:
+                        sch->qstats.overlimits++;
+                        if (!red_use_ecn(q) || !INET_ECN_set_ce(skb)) {
+                                q->stats.prob_drop++;
+                                goto congestion_drop;
+                        }
 
-        if (q->qave < q->qth_min) {
-                q->qcount = -1;
-enqueue:
-                if (sch->qstats.backlog + skb->len <= q->limit) {
-                        __skb_queue_tail(&sch->q, skb);
-                        sch->qstats.backlog += skb->len;
-                        sch->bstats.bytes += skb->len;
-                        sch->bstats.packets++;
-                        return NET_XMIT_SUCCESS;
-                } else {
-                        q->st.pdrop++;
-                }
-                kfree_skb(skb);
-                sch->qstats.drops++;
-                return NET_XMIT_DROP;
-        }
-        if (q->qave >= q->qth_max) {
-                q->qcount = -1;
-                sch->qstats.overlimits++;
-mark:
-                if  (!(q->flags&TC_RED_ECN) || !red_ecn_mark(skb)) {
-                        q->st.early++;
-                        goto drop;
-                }
-                q->st.marked++;
-                goto enqueue;
-        }
+                        q->stats.prob_mark++;
+                        break;
+
+                case RED_HARD_MARK:
+                        sch->qstats.overlimits++;
+                        if (red_use_harddrop(q) || !red_use_ecn(q) ||
+                            !INET_ECN_set_ce(skb)) {
+                                q->stats.forced_drop++;
+                                goto congestion_drop;
+                        }
 
-        if (++q->qcount) {
-                /* The formula used below causes questions.
-
-                   OK. qR is random number in the interval 0..Rmask
-                   i.e. 0..(2^Plog). If we used floating point
-                   arithmetics, it would be: (2^Plog)*rnd_num,
-                   where rnd_num is less 1.
-
-                   Taking into account, that qave have fixed
-                   point at Wlog, and Plog is related to max_P by
-                   max_P = (qth_max-qth_min)/2^Plog; two lines
-                   below have the following floating point equivalent:
-                   
-                   max_P*(qave - qth_min)/(qth_max-qth_min) < rnd/qcount
-
-                   Any questions? --ANK (980924)
-                 */
-                if (((q->qave - q->qth_min)>>q->Wlog)*q->qcount < q->qR)
-                        goto enqueue;
-                q->qcount = 0;
-                q->qR = net_random()&q->Rmask;
-                sch->qstats.overlimits++;
-                goto mark;
+                        q->stats.forced_mark++;
+                        break;
         }
-        q->qR = net_random()&q->Rmask;
-        goto enqueue;
 
-drop:
-        kfree_skb(skb);
-        sch->qstats.drops++;
+        if (sch->qstats.backlog + skb->len <= q->limit)
+                return qdisc_enqueue_tail(skb, sch);
+
+        q->stats.pdrop++;
+        return qdisc_drop(skb, sch);
+
+congestion_drop:
+        qdisc_drop(skb, sch);
         return NET_XMIT_CN;
 }
 
-static int
-red_requeue(struct sk_buff *skb, struct Qdisc* sch)
+static int red_requeue(struct sk_buff *skb, struct Qdisc* sch)
 {
         struct red_sched_data *q = qdisc_priv(sch);
 
-        PSCHED_SET_PASTPERFECT(q->qidlestart);
+        if (red_is_idling(&q->parms))
+                red_end_of_idle_period(&q->parms);
 
-        __skb_queue_head(&sch->q, skb);
-        sch->qstats.backlog += skb->len;
-        sch->qstats.requeues++;
-        return 0;
+        return qdisc_requeue(skb, sch);
 }
 
-static struct sk_buff *
-red_dequeue(struct Qdisc* sch)
+static struct sk_buff * red_dequeue(struct Qdisc* sch)
 {
         struct sk_buff *skb;
         struct red_sched_data *q = qdisc_priv(sch);
 
-        skb = __skb_dequeue(&sch->q);
-        if (skb) {
-                sch->qstats.backlog -= skb->len;
-                return skb;
-        }
-        PSCHED_GET_TIME(q->qidlestart);
-        return NULL;
+        skb = qdisc_dequeue_head(sch);
+
+        if (skb == NULL && !red_is_idling(&q->parms))
+                red_start_of_idle_period(&q->parms);
+
+        return skb;
 }
 
 static unsigned int red_drop(struct Qdisc* sch)
@@ -333,16 +130,17 @@ static unsigned int red_drop(struct Qdisc* sch)
         struct sk_buff *skb;
         struct red_sched_data *q = qdisc_priv(sch);
 
-        skb = __skb_dequeue_tail(&sch->q);
+        skb = qdisc_dequeue_tail(sch);
         if (skb) {
                 unsigned int len = skb->len;
-                sch->qstats.backlog -= len;
-                sch->qstats.drops++;
-                q->st.other++;
-                kfree_skb(skb);
+                q->stats.other++;
+                qdisc_drop(skb, sch);
                 return len;
         }
-        PSCHED_GET_TIME(q->qidlestart);
+
+        if (!red_is_idling(&q->parms))
+                red_start_of_idle_period(&q->parms);
+
         return 0;
 }
 
@@ -350,43 +148,38 @@ static void red_reset(struct Qdisc* sch)
 {
         struct red_sched_data *q = qdisc_priv(sch);
 
-        __skb_queue_purge(&sch->q);
-        sch->qstats.backlog = 0;
-        PSCHED_SET_PASTPERFECT(q->qidlestart);
-        q->qave = 0;
-        q->qcount = -1;
+        qdisc_reset_queue(sch);
+        red_restart(&q->parms);
 }
 
 static int red_change(struct Qdisc *sch, struct rtattr *opt)
 {
         struct red_sched_data *q = qdisc_priv(sch);
-        struct rtattr *tb[TCA_RED_STAB];
+        struct rtattr *tb[TCA_RED_MAX];
         struct tc_red_qopt *ctl;
 
-        if (opt == NULL ||
-            rtattr_parse_nested(tb, TCA_RED_STAB, opt) ||
-            tb[TCA_RED_PARMS-1] == 0 || tb[TCA_RED_STAB-1] == 0 ||
+        if (opt == NULL || rtattr_parse_nested(tb, TCA_RED_MAX, opt))
+                return -EINVAL;
+
+        if (tb[TCA_RED_PARMS-1] == NULL ||
             RTA_PAYLOAD(tb[TCA_RED_PARMS-1]) < sizeof(*ctl) ||
-            RTA_PAYLOAD(tb[TCA_RED_STAB-1]) < 256)
+            tb[TCA_RED_STAB-1] == NULL ||
+            RTA_PAYLOAD(tb[TCA_RED_STAB-1]) < RED_STAB_SIZE)
                 return -EINVAL;
 
         ctl = RTA_DATA(tb[TCA_RED_PARMS-1]);
 
         sch_tree_lock(sch);
         q->flags = ctl->flags;
-        q->Wlog = ctl->Wlog;
-        q->Plog = ctl->Plog;
-        q->Rmask = ctl->Plog < 32 ? ((1<<ctl->Plog) - 1) : ~0UL;
-        q->Scell_log = ctl->Scell_log;
-        q->Scell_max = (255<<q->Scell_log);
-        q->qth_min = ctl->qth_min<<ctl->Wlog;
-        q->qth_max = ctl->qth_max<<ctl->Wlog;
         q->limit = ctl->limit;
-        memcpy(q->Stab, RTA_DATA(tb[TCA_RED_STAB-1]), 256);
 
-        q->qcount = -1;
+        red_set_parms(&q->parms, ctl->qth_min, ctl->qth_max, ctl->Wlog,
+                                 ctl->Plog, ctl->Scell_log,
+                                 RTA_DATA(tb[TCA_RED_STAB-1]));
+
         if (skb_queue_empty(&sch->q))
-                PSCHED_SET_PASTPERFECT(q->qidlestart);
+                red_end_of_idle_period(&q->parms);
+
         sch_tree_unlock(sch);
         return 0;
 }
@@ -399,39 +192,39 @@ static int red_init(struct Qdisc* sch, struct rtattr *opt)
 static int red_dump(struct Qdisc *sch, struct sk_buff *skb)
 {
         struct red_sched_data *q = qdisc_priv(sch);
-        unsigned char    *b = skb->tail;
-        struct rtattr *rta;
-        struct tc_red_qopt opt;
-
-        rta = (struct rtattr*)b;
-        RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
-        opt.limit = q->limit;
-        opt.qth_min = q->qth_min>>q->Wlog;
-        opt.qth_max = q->qth_max>>q->Wlog;
-        opt.Wlog = q->Wlog;
-        opt.Plog = q->Plog;
-        opt.Scell_log = q->Scell_log;
-        opt.flags = q->flags;
+        struct rtattr *opts = NULL;
+        struct tc_red_qopt opt = {
+                .limit          = q->limit,
+                .flags          = q->flags,
+                .qth_min        = q->parms.qth_min >> q->parms.Wlog,
+                .qth_max        = q->parms.qth_max >> q->parms.Wlog,
+                .Wlog           = q->parms.Wlog,
+                .Plog           = q->parms.Plog,
+                .Scell_log      = q->parms.Scell_log,
+        };
+
+        opts = RTA_NEST(skb, TCA_OPTIONS);
         RTA_PUT(skb, TCA_RED_PARMS, sizeof(opt), &opt);
-        rta->rta_len = skb->tail - b;
-
-        return skb->len;
+        return RTA_NEST_END(skb, opts);
 
 rtattr_failure:
-        skb_trim(skb, b - skb->data);
-        return -1;
+        return RTA_NEST_CANCEL(skb, opts);
 }
 
 static int red_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
 {
         struct red_sched_data *q = qdisc_priv(sch);
-
-        return gnet_stats_copy_app(d, &q->st, sizeof(q->st));
+        struct tc_red_xstats st = {
+                .early  = q->stats.prob_drop + q->stats.forced_drop,
+                .pdrop  = q->stats.pdrop,
+                .other  = q->stats.other,
+                .marked = q->stats.prob_mark + q->stats.forced_mark,
+        };
+
+        return gnet_stats_copy_app(d, &st, sizeof(st));
 }
 
 static struct Qdisc_ops red_qdisc_ops = {
-        .next           =       NULL,
-        .cl_ops         =       NULL,
         .id             =       "red",
         .priv_size      =       sizeof(struct red_sched_data),
         .enqueue        =       red_enqueue,
@@ -450,10 +243,13 @@ static int __init red_module_init(void)
 {
         return register_qdisc(&red_qdisc_ops);
 }
-static void __exit red_module_exit(void) 
+
+static void __exit red_module_exit(void)
 {
         unregister_qdisc(&red_qdisc_ops);
 }
+
 module_init(red_module_init)
 module_exit(red_module_exit)
+
 MODULE_LICENSE("GPL");