redis/internal/pool/conn_check.go

55 lines
967 B
Go

//go:build linux || darwin || dragonfly || freebsd || netbsd || openbsd || solaris || illumos
package pool
import (
"crypto/tls"
"errors"
"io"
"net"
"syscall"
"time"
)
var errUnexpectedRead = errors.New("unexpected read from socket")
func connCheck(conn net.Conn) error {
// Reset previous timeout.
_ = conn.SetDeadline(time.Time{})
// Check if tls.Conn.
if c, ok := conn.(*tls.Conn); ok {
conn = c.NetConn()
}
sysConn, ok := conn.(syscall.Conn)
if !ok {
return nil
}
rawConn, err := sysConn.SyscallConn()
if err != nil {
return err
}
var sysErr error
if err := rawConn.Read(func(fd uintptr) bool {
var buf [1]byte
n, err := syscall.Read(int(fd), buf[:])
switch {
case n == 0 && err == nil:
sysErr = io.EOF
case n > 0:
sysErr = errUnexpectedRead
case err == syscall.EAGAIN || err == syscall.EWOULDBLOCK:
sysErr = nil
default:
sysErr = err
}
return true
}); err != nil {
return err
}
return sysErr
}