54 lines
1.3 KiB
Go
54 lines
1.3 KiB
Go
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//go:build aix || darwin || dragonfly || freebsd || (js && wasm) || linux || nacl || netbsd || openbsd || solaris
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package tlsmiddlebox
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//
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// syscall utilities for dialerTTLWrapperConn
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//
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import (
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"net"
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"syscall"
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)
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// SetTTL sets the IP TTL field for the underlying net.TCPConn
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func (c *dialerTTLWrapperConn) SetTTL(ttl int) error {
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conn := c.Conn
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tcpConn, ok := conn.(*net.TCPConn)
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if !ok {
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return errInvalidConnWrapper
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}
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rawConn, err := tcpConn.SyscallConn()
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if err != nil {
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return err
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}
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rawErr := rawConn.Control(func(fd uintptr) {
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err = syscall.SetsockoptInt(int(fd), syscall.IPPROTO_IP, syscall.IP_TTL, ttl)
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})
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// The syscall err is given a higher priority and returned early if non-nil
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if err != nil {
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return err
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}
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return rawErr
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}
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// GetSoErr fetches the SO_ERROR value to look for soft ICMP errors in TCP
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func (c *dialerTTLWrapperConn) GetSoErr() (errno int, err error) {
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conn := c.Conn
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tcpConn, ok := conn.(*net.TCPConn)
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if !ok {
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return 0, errInvalidConnWrapper
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}
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rawConn, err := tcpConn.SyscallConn()
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if err != nil {
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return 0, errInvalidConnWrapper
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}
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rawErr := rawConn.Control(func(fd uintptr) {
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errno, err = syscall.GetsockoptInt(int(fd), syscall.SOL_SOCKET, syscall.SO_ERROR)
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})
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if rawErr != nil {
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return 0, rawErr
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}
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return
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}
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