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mirror of https://github.com/cwinfo/yggdrasil-go.git synced 2024-12-23 11:05:40 +00:00

when we detect we're blocked, only drop packets often enough to make sure the existing queue's size is non-increasing, and always drop the worst packet from a random flow with odds based on the total size of packets queued for that flow

This commit is contained in:
Arceliar 2020-05-17 12:09:40 -05:00
parent 6e92af1cd2
commit 7720e169f2
2 changed files with 22 additions and 30 deletions

View File

@ -1,6 +1,7 @@
package yggdrasil
import (
"math/rand"
"time"
)
@ -28,32 +29,19 @@ func (q *packetQueue) drop() bool {
if q.size == 0 {
return false
}
// TODO? drop from a random stream
// odds proportional to size? bandwidth?
// always using the worst is exploitable -> flood 1 packet per random stream
// find the stream that's using the most bandwidth
now := time.Now()
// select a random stream, odds based on stream size
offset := rand.Uint64() % q.size
var worst pqStreamID
for id := range q.streams {
worst = id
break // get a random ID to start
}
worstStream := q.streams[worst]
worstSize := float64(worstStream.size)
worstAge := now.Sub(worstStream.infos[0].time).Seconds()
var size uint64
for id, stream := range q.streams {
thisSize := float64(stream.size)
thisAge := now.Sub(stream.infos[0].time).Seconds()
// cross multiply to avoid division by zero issues
if worstSize*thisAge < thisSize*worstAge {
// worstSize/worstAge < thisSize/thisAge -> this uses more bandwidth
worst = id
worstStream = stream
worstSize = thisSize
worstAge = thisAge
worst = id
size += stream.size
if size >= offset {
break
}
}
// Drop the oldest packet from the worst stream
// drop the oldest packet from the stream
worstStream := q.streams[worst]
packet := worstStream.infos[0].packet
worstStream.infos = worstStream.infos[1:]
worstStream.size -= uint64(len(packet))

View File

@ -110,6 +110,7 @@ type peer struct {
queue packetQueue
seq uint64 // this and idle are used to detect when to drop packets from queue
idle bool
drop bool // set to true if we're dropping packets from the queue
}
func (ps *peers) updateTables(from phony.Actor, table *lookupTable) {
@ -275,13 +276,19 @@ func (p *peer) sendPacketsFrom(from phony.Actor, packets [][]byte) {
}
func (p *peer) _sendPackets(packets [][]byte) {
size := p.queue.size
for _, packet := range packets {
p.queue.push(packet)
}
if p.idle {
switch {
case p.idle:
p.idle = false
p._handleIdle()
} else {
case p.drop:
for p.queue.size > size {
p.queue.drop()
}
default:
p.intf.notifyQueued(p.seq)
}
}
@ -303,17 +310,14 @@ func (p *peer) _handleIdle() {
p.intf.out(packets)
} else {
p.idle = true
p.drop = false
}
}
func (p *peer) dropFromQueue(from phony.Actor, seq uint64) {
p.Act(from, func() {
switch {
case seq != p.seq:
case p.queue.size < streamMsgSize:
case p.queue.drop():
p.core.log.Debugln("DEBUG dropped:", p.port, p.queue.size)
p.intf.notifyQueued(p.seq)
if seq == p.seq {
p.drop = true
}
})
}