const golang.org/x/sys/unix.TCP_MD5SIG_FLAG_IFINDEX

one use

	golang.org/x/sys/unix (current package)
		zerrors_linux.go#L3400: 	TCP_MD5SIG_FLAG_IFINDEX                     = 0x2

The pages are generated with Golds v0.7.6. (GOOS=linux GOARCH=amd64)