[netboot] Use RawConn in NewLogListener
A suggested refactoring of raggi@'s to tidy up the locking, CloseOnExec,
and file descriptor logic.
Test: successfully listened locally.
Change-Id: Idd8a99a728b73c93d24674730e09879346dc9946
diff --git a/netboot/loglistener.go b/netboot/loglistener.go
index 96a9661..982232a 100644
--- a/netboot/loglistener.go
+++ b/netboot/loglistener.go
@@ -9,8 +9,8 @@
"bytes"
"encoding/binary"
"errors"
+ "fmt"
"net"
- "os"
"syscall"
"golang.org/x/sys/unix"
@@ -37,45 +37,41 @@
// LogListener is Zircon's debug log listener.
type LogListener struct {
seq uint32
- conn net.PacketConn
+ conn *net.UDPConn
nodename string
}
// NewLogListener creates and connects a new instance of debug log listener.
func NewLogListener(nodename string) (*LogListener, error) {
- syscall.ForkLock.RLock()
- fd, err := syscall.Socket(syscall.AF_INET6, syscall.SOCK_DGRAM, syscall.IPPROTO_UDP)
- if err == nil {
- unix.CloseOnExec(fd)
+ conn, err := net.ListenUDP("udp6", &net.UDPAddr{
+ IP: net.IPv6zero,
+ Port: debugPort,
+ })
+ if err != nil {
+ return nil, fmt.Errorf("failed to bind to udp6 port: %v\n", err)
}
- syscall.ForkLock.RUnlock()
+
+ rawConn, err := conn.SyscallConn()
if err != nil {
return nil, err
}
// SO_REUSEADDR and SO_REUSEPORT allows binding to the same port multiple
// times which is necessary in the case when there are multiple instances.
- if err := syscall.SetsockoptInt(fd, syscall.SOL_SOCKET, unix.SO_REUSEADDR, 1); err != nil {
- syscall.Close(fd)
+ var fderr error
+ if err = rawConn.Control(func(fd uintptr) {
+ if fderr = syscall.SetsockoptInt(int(fd), syscall.SOL_SOCKET, unix.SO_REUSEADDR, 1); fderr != nil {
+ return
+ }
+
+ if fderr = syscall.SetsockoptInt(int(fd), syscall.SOL_SOCKET, unix.SO_REUSEPORT, 1); fderr != nil {
+ return
+ }
+ }); err != nil {
return nil, err
}
-
- if err := syscall.SetsockoptInt(fd, syscall.SOL_SOCKET, unix.SO_REUSEPORT, 1); err != nil {
- syscall.Close(fd)
- return nil, err
- }
-
- // Bind the socket to the default debug log listener port.
- if err := syscall.Bind(fd, &syscall.SockaddrInet6{Port: debugPort}); err != nil {
- syscall.Close(fd)
- return nil, err
- }
-
- f := os.NewFile(uintptr(fd), "")
- conn, err := net.FilePacketConn(f)
- f.Close()
- if err != nil {
- return nil, err
+ if fderr != nil {
+ return nil, fderr
}
return &LogListener{
