package/qos-scripts/files/usr/lib/qos/tcrules.awk

   1 BEGIN {
   2         dmax=100
   3         if (!(linespeed > 0)) linespeed = 128
   4         FS=":"
   5         n = 0
   6 }
   7
   8 ($1 != "") {
   9         n++
  10         class[n] = $1
  11         prio[n] = $2
  12         avgrate[n] = ($3 * linespeed / 100)
  13         pktsize[n] = $4
  14         delay[n] = $5
  15         maxrate[n] = ($6 * linespeed / 100)
  16 }
  17
  18 END {
  19         allocated = 0
  20         maxdelay = 0
  21
  22         for (i = 1; i <= n; i++) {
  23                 # set defaults
  24                 if (!(pktsize[i] > 0)) pktsize[i] = 1500
  25                 if (!(prio[i] > 0)) prio[i] = 1
  26
  27                 allocated += avgrate[i]
  28                 sum_prio += prio[i]
  29                 if ((avgrate[i] > 0) && !(delay[i] > 0)) {
  30                         sum_rtprio += prio[i]
  31                 }
  32         }
  33
  34         # allocation of m1 in rt classes:
  35         # sum(d * m1) must not exceed dmax * (linespeed - allocated)
  36         dmax = 0
  37         for (i = 1; i <= n; i++) {
  38                 if (avgrate[i] > 0) {
  39                         rtm2[i] = avgrate[i]
  40                         if (delay[i] > 0) {
  41                                 d[i] = delay[i]
  42                         } else {
  43                                 d[i] = 2 * pktsize[i] * 1000 / (linespeed * 1024)
  44                                 if (d[i] > dmax) dmax = d[i]
  45                         }
  46                 }
  47         }
  48
  49         ds_avail = dmax * (linespeed - allocated)
  50         for (i = 1; i <= n; i++) {
  51                 lsm1[i] = 0
  52                 rtm1[i] = 0
  53                 lsm2[i] = linespeed * prio[i] / sum_prio
  54                 if ((avgrate[i] > 0) && (d[i] > 0)) {
  55                         if (!(delay[i] > 0)) {
  56                                 ds = ds_avail * prio[i] / sum_rtprio
  57                                 ds_avail -= ds
  58                                 rtm1[i] = rtm2[i] + ds/d[i]
  59                         }
  60                         lsm1[i] = rtm1[i]
  61                 }
  62                 else {
  63                         d[i] = 0
  64                 }
  65         }
  66
  67         # main qdisc
  68         for (i = 1; i <= n; i++) {
  69                 printf "tc class add dev "device" parent 1:1 classid 1:"class[i]"0 hfsc"
  70                 if (rtm1[i] > 0) {
  71                         printf " rt m1 " int(rtm1[i]) "kbit d " int(d[i] * 1000) "us m2 " int(rtm2[i])"kbit"
  72                 }
  73                 printf " ls m1 " int(lsm1[i]) "kbit d " int(d[i] * 1000) "us m2 " int(lsm2[i]) "kbit"
  74                 print " ul rate " int(maxrate[i]) "kbit"
  75         }
  76
  77         # leaf qdisc
  78         avpkt = 1200
  79         for (i = 1; i <= n; i++) {
  80                 printf "tc qdisc add dev "device" parent 1:"class[i]"0 handle "class[i]"00: "
  81
  82                 # RED parameters - also used to determine the queue length for sfq
  83                 # calculate min value. for links <= 256 kbit, we use 1500 bytes
  84                 # use 50 ms queue length as min threshold for faster links
  85                 # max threshold is fixed to 3*min
  86                 base_pkt=3000
  87                 base_rate=256
  88                 min_lat=50
  89                 if (maxrate[i] <= base_rate) min = base_pkt
  90                 else min = int(maxrate[i] * 1024 / 8 * 0.05)
  91                 max = 3 * min
  92                 limit = (min + max) * 3
  93
  94                 if (rtm1[i] > 0) {
  95                         # rt class - use sfq
  96                         print "sfq perturb 2 limit "  limit
  97                 } else {
  98                         # non-rt class - use RED
  99
 100                         avpkt = pktsize[i]
 101                         # don't use avpkt values less than 500 bytes
 102                         if (avpkt < 500) avpkt = 500
 103                         # if avpkt is too close to min, scale down avpkt to allow proper bursting
 104                         if (avpkt > min * 0.70) avpkt *= 0.70
 105
 106
 107                         # according to http://www.cs.unc.edu/~jeffay/papers/IEEE-ToN-01.pdf a drop
 108                         # probability somewhere between 0.1 and 0.2 should be a good tradeoff
 109                         # between link utilization and response time (0.1: response; 0.2: utilization)
 110                         prob="0.12"
 111
 112                         rburst=int((2*min + max) / (3 * avpkt))
 113                         if (rburst < 2) rburst = 2
 114                         print "red min " min " max " max " burst " rburst " avpkt " avpkt " limit " limit " probability " prob " ecn"
 115                 }
 116         }
 117
 118         # filter rule
 119         for (i = 1; i <= n; i++) {
 120                 print "tc filter add dev "device" parent 1: prio "class[i]" protocol ip handle "class[i]" fw flowid 1:"class[i] "0"
 121         }
 122 }
 123