fix non-linux builds

irc/utils/net_linux.go

@@ -0,0 +1,31 @@
+// +build linux
+
+package utils
+
+import (
+	"fmt"
+	"net"
+	"syscall"
+)
+
+// Output a description of a connection that can identify it to other systems
+// administration tools.
+func DescribeConn(c net.Conn) (description string) {
+	description = "<error>"
+	switch conn := c.(type) {
+	case *net.UnixConn:
+		f, err := conn.File()
+		if err != nil {
+			return
+		}
+		defer f.Close()
+		ucred, err := syscall.GetsockoptUcred(int(f.Fd()), syscall.SOL_SOCKET, syscall.SO_PEERCRED)
+		if err != nil {
+			return
+		}
+		return fmt.Sprintf("%s <-> %s [pid=%d, uid=%d]", conn.LocalAddr().String(), conn.RemoteAddr().String(), ucred.Pid, ucred.Uid)
+	default:
+		// *net.TCPConn or *tls.Conn
+		return fmt.Sprintf("%s <-> %s", conn.LocalAddr().String(), conn.RemoteAddr().String())
+	}
+}