mirror of
https://github.com/MetaCubeX/mihomo.git
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67 lines
1.4 KiB
Go
67 lines
1.4 KiB
Go
package core
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func fragUDPMessage(m udpMessage, maxSize int) []udpMessage {
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if m.Size() <= maxSize {
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return []udpMessage{m}
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}
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fullPayload := m.Data
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maxPayloadSize := maxSize - m.HeaderSize()
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off := 0
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fragID := uint8(0)
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fragCount := uint8((len(fullPayload) + maxPayloadSize - 1) / maxPayloadSize) // round up
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var frags []udpMessage
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for off < len(fullPayload) {
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payloadSize := len(fullPayload) - off
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if payloadSize > maxPayloadSize {
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payloadSize = maxPayloadSize
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}
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frag := m
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frag.FragID = fragID
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frag.FragCount = fragCount
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frag.DataLen = uint16(payloadSize)
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frag.Data = fullPayload[off : off+payloadSize]
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frags = append(frags, frag)
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off += payloadSize
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fragID++
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}
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return frags
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}
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type defragger struct {
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msgID uint16
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frags []*udpMessage
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count uint8
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}
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func (d *defragger) Feed(m udpMessage) *udpMessage {
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if m.FragCount <= 1 {
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return &m
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}
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if m.FragID >= m.FragCount {
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// wtf is this?
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return nil
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}
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if m.MsgID != d.msgID {
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// new message, clear previous state
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d.msgID = m.MsgID
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d.frags = make([]*udpMessage, m.FragCount)
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d.count = 1
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d.frags[m.FragID] = &m
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} else if d.frags[m.FragID] == nil {
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d.frags[m.FragID] = &m
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d.count++
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if int(d.count) == len(d.frags) {
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// all fragments received, assemble
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var data []byte
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for _, frag := range d.frags {
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data = append(data, frag.Data...)
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}
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m.DataLen = uint16(len(data))
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m.Data = data
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m.FragID = 0
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m.FragCount = 1
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return &m
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}
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}
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return nil
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}
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