mirror of
https://github.com/qdm12/gluetun.git
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Quentin McGaw
04d7cef294
- this makes PMTUD TCP reliable - this only works on kernels with the mark module - on kernels without the mark module, the icmp pmtud mtu found is used
19 lines
643 B
Go
19 lines
643 B
Go
package tcp
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import "golang.org/x/sys/unix"
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// setMark sets a mark on each packets sent through this socket.
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// This is used in conjunction with iptables to block outgoing kernel automated
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// RST packets, since the kernel is not aware of us handling the connection manually.
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// For example:
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// iptables -A OUTPUT -p tcp --tcp-flags RST RST -m mark ! --mark 123 -j DROP
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//
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//nolint:dupword
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func setMark(fd, excludeMark int) error {
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return unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_MARK, excludeMark)
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}
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func setMTUDiscovery(fd int) error {
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return unix.SetsockoptInt(fd, unix.IPPROTO_IP, unix.IP_MTU_DISCOVER, unix.IP_PMTUDISC_PROBE)
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}
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