65 lines
1.4 KiB
Go
65 lines
1.4 KiB
Go
//go:build !windows
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package packet
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import (
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"net"
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"strconv"
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"syscall"
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"github.com/Dreamacro/clash/common/pool"
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)
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type enhanceUDPConn struct {
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*net.UDPConn
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rawConn syscall.RawConn
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}
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func (c *enhanceUDPConn) WaitReadFrom() (data []byte, put func(), addr net.Addr, err error) {
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if c.rawConn == nil {
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c.rawConn, _ = c.UDPConn.SyscallConn()
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}
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var readErr error
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err = c.rawConn.Read(func(fd uintptr) (done bool) {
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readBuf := pool.Get(pool.UDPBufferSize)
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put = func() {
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_ = pool.Put(readBuf)
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}
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var readFrom syscall.Sockaddr
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var readN int
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readN, _, _, readFrom, readErr = syscall.Recvmsg(int(fd), readBuf, nil, 0)
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if readN > 0 {
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data = readBuf[:readN]
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} else {
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put()
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put = nil
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data = nil
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}
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if readErr == syscall.EAGAIN {
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return false
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}
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if readFrom != nil {
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switch from := readFrom.(type) {
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case *syscall.SockaddrInet4:
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ip := from.Addr // copy from.Addr; ip escapes, so this line allocates 4 bytes
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addr = &net.UDPAddr{IP: ip[:], Port: from.Port}
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case *syscall.SockaddrInet6:
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ip := from.Addr // copy from.Addr; ip escapes, so this line allocates 16 bytes
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addr = &net.UDPAddr{IP: ip[:], Port: from.Port, Zone: strconv.FormatInt(int64(from.ZoneId), 10)}
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}
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}
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// udp should not convert readN == 0 to io.EOF
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//if readN == 0 {
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// readErr = io.EOF
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//}
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return true
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})
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if err != nil {
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return
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}
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if readErr != nil {
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err = readErr
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return
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}
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return
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}
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