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

1BEGIN {
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    qdisc[n] = $7
17    filter[n] = $8
18}
19
20END {
21    allocated = 0
22    maxdelay = 0
23
24    for (i = 1; i <= n; i++) {
25        # set defaults
26        if (!(pktsize[i] > 0)) pktsize[i] = 1500
27        if (!(prio[i] > 0)) prio[i] = 1
28
29        allocated += avgrate[i]
30        sum_prio += prio[i]
31        if ((avgrate[i] > 0) && !(delay[i] > 0)) {
32            sum_rtprio += prio[i]
33        }
34    }
35    
36    # allocation of m1 in rt classes:
37    # sum(d * m1) must not exceed dmax * (linespeed - allocated)
38    dmax = 0
39    for (i = 1; i <= n; i++) {
40        if (avgrate[i] > 0) {
41            rtm2[i] = avgrate[i]
42            if (delay[i] > 0) {
43                d[i] = delay[i]
44            } else {
45                d[i] = 2 * pktsize[i] * 1000 / (linespeed * 1024)
46                if (d[i] > dmax) dmax = d[i]
47            }
48        }
49    }
50
51    ds_avail = dmax * (linespeed - allocated)
52    for (i = 1; i <= n; i++) {
53        lsm1[i] = 0
54        rtm1[i] = 0
55        lsm2[i] = linespeed * prio[i] / sum_prio
56        if ((avgrate[i] > 0) && (d[i] > 0)) {
57            if (!(delay[i] > 0)) {
58                ds = ds_avail * prio[i] / sum_rtprio
59                ds_avail -= ds
60                rtm1[i] = rtm2[i] + ds/d[i]
61            }
62            lsm1[i] = rtm1[i]
63        }
64        else {
65            d[i] = 0
66        }
67    }
68
69    # main qdisc
70    for (i = 1; i <= n; i++) {
71        printf "tc class add dev "device" parent 1:1 classid 1:"class[i]"0 hfsc"
72        if (rtm1[i] > 0) {
73            printf " rt m1 " int(rtm1[i]) "kbit d " int(d[i] * 1000) "us m2 " int(rtm2[i])"kbit"
74        }
75        printf " ls m1 " int(lsm1[i]) "kbit d " int(d[i] * 1000) "us m2 " int(lsm2[i]) "kbit"
76        print " ul rate " int(maxrate[i]) "kbit"
77    }
78
79    # leaf qdisc
80    avpkt = 1200
81    for (i = 1; i <= n; i++) {
82        printf "tc qdisc add dev "device" parent 1:"class[i]"0 handle "class[i]"00: "
83
84        # RED parameters - also used to determine the queue length for sfq
85        # calculate min value. for links <= 256 kbit, we use 1500 bytes
86        # use 50 ms queue length as min threshold for faster links
87        # max threshold is fixed to 3*min
88        base_pkt=3000
89        base_rate=256
90        min_lat=50
91        if (maxrate[i] <= base_rate) min = base_pkt
92        else min = int(maxrate[i] * 1024 / 8 * 0.05)
93        max = 3 * min
94        limit = (min + max) * 3
95
96        if (qdisc[i] != "") {
97            # user specified qdisc
98            print qdisc[i] " limit " limit
99        } else if (rtm1[i] > 0) {
100            # rt class - use sfq
101            print "sfq perturb 2 limit " limit
102        } else {
103            # non-rt class - use RED
104
105            avpkt = pktsize[i]
106            # don't use avpkt values less than 500 bytes
107            if (avpkt < 500) avpkt = 500
108            # if avpkt is too close to min, scale down avpkt to allow proper bursting
109            if (avpkt > min * 0.70) avpkt *= 0.70
110
111
112            # according to http://www.cs.unc.edu/~jeffay/papers/IEEE-ToN-01.pdf a drop
113            # probability somewhere between 0.1 and 0.2 should be a good tradeoff
114            # between link utilization and response time (0.1: response; 0.2: utilization)
115            prob="0.12"
116        
117            rburst=int((2*min + max) / (3 * avpkt))
118            if (rburst < 2) rburst = 2
119            print "red min " min " max " max " burst " rburst " avpkt " avpkt " limit " limit " probability " prob " ecn"
120        }
121    }
122    
123    # filter rule
124    for (i = 1; i <= n; i++) {
125        print "tc filter add dev "device" parent 1: prio "class[i]" protocol ip handle "class[i]"/0xff fw flowid 1:"class[i] "0"
126        filterc=1
127        if (filter[i] != "") {
128            print " tc filter add dev "device" parent "class[i]"00: handle "filterc"0 "filter[i]
129            filterc=filterc+1
130        }
131    }
132}
133
134

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