mirror of
https://github.com/qdm12/gluetun.git
synced 2026-05-07 04:20:12 +02:00
Quentin McGaw
40 lines
1.2 KiB
Go
40 lines
1.2 KiB
Go
package test
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import (
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"fmt"
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"math"
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)
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// MakeMTUsToTest determines a slice of MTU values to test
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// between minMTU and maxMTU inclusive. It creates an MTU
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// slice of length up to 11 MTUs such that:
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// - the first element is the minMTU
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// - the last element is the maxMTU
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// - elements in-between are separated as close to each other
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// The number 11 is chosen to find the final MTU in 3 searches,
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// with a total search space of 1728 MTUs which is enough;
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// to find it in 2 searches requires 37 parallel queries which
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// could be blocked by firewalls.
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func MakeMTUsToTest(minMTU, maxMTU uint32) (mtus []uint32) {
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const mtusLength = 11 // find the final MTU in 3 searches
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diff := maxMTU - minMTU
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switch {
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case minMTU > maxMTU:
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panic(fmt.Sprintf("minMTU %d is greater than maxMTU %d", minMTU, maxMTU))
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case diff <= mtusLength:
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mtus = make([]uint32, 0, diff)
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for mtu := minMTU; mtu <= maxMTU; mtu++ {
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mtus = append(mtus, mtu)
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}
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default:
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step := float64(diff) / float64(mtusLength-1)
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mtus = make([]uint32, 0, mtusLength)
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for mtu := float64(minMTU); len(mtus) < mtusLength-1; mtu += step {
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mtus = append(mtus, uint32(math.Round(mtu)))
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}
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mtus = append(mtus, maxMTU) // last element is the maxMTU
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}
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return mtus
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}
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