code review 7252045: net: use windows GetAddrInfoW in LookupPort when possible

net: use windows GetAddrInfoW in LookupPort when possible

[brainman, 2013-02-01 06:03:57]

Hello golang-dev@googlegroups.com,

I'd like you to review this change to
https://go.googlecode.com/hg/

[bradfitz, 2013-02-01 17:47:31]

LGTM

On Thu, Jan 31, 2013 at 10:03 PM, <alex.brainman@gmail.com> wrote:

> Reviewers: golang-dev_googlegroups.com,
>
> Message:
> Hello golang-dev@googlegroups.com,
>
> I'd like you to review this change to
> https://go.googlecode.com/hg/
>
>
> Description:
> net: use windows GetAddrInfoW in LookupPort when possible
>
> Please review this at
https://codereview.appspot.**com/7252045/<https://codereview.appspot.com/7252...
>
> Affected files:
>   M src/pkg/net/fd_windows.go
>   M src/pkg/net/lookup_windows.go
>   M src/pkg/net/port_test.go
>
>
> Index: src/pkg/net/fd_windows.go
> ==============================**==============================**=======
> --- a/src/pkg/net/fd_windows.go
> +++ b/src/pkg/net/fd_windows.go
> @@ -37,6 +37,7 @@
>         }
>         canCancelIO = syscall.LoadCancelIoEx() == nil
>         if syscall.LoadGetAddrInfo() == nil {
> +               lookupPort = newLookupPort
>                 lookupIP = newLookupIP
>         }
>  }
> Index: src/pkg/net/lookup_windows.go
> ==============================**==============================**=======
> --- a/src/pkg/net/lookup_windows.**go
> +++ b/src/pkg/net/lookup_windows.**go
> @@ -17,6 +17,11 @@
>         serventLock  sync.Mutex
>  )
>
> +var (
> +       lookupPort = oldLookupPort
> +       lookupIP   = oldLookupIP
> +)
> +
>  // lookupProtocol looks up IP protocol name and returns correspondent
> protocol number.
>  func lookupProtocol(name string) (proto int, err error) {
>         protoentLock.Lock()
> @@ -40,8 +45,6 @@
>         return
>  }
>
> -var lookupIP = oldLookupIP
> -
>  func oldLookupIP(name string) (addrs []IP, err error) {
>         hostentLock.Lock()
>         defer hostentLock.Unlock()
> @@ -92,7 +95,7 @@
>         return addrs, nil
>  }
>
> -func lookupPort(network, service string) (port int, err error) {
> +func oldLookupPort(network, service string) (port int, err error) {
>         switch network {
>         case "tcp4", "tcp6":
>                 network = "tcp"
> @@ -108,6 +111,40 @@
>         return int(syscall.Ntohs(s.Port)), nil
>  }
>
> +func newLookupPort(network, service string) (port int, err error) {
> +       var stype int32
> +       switch network {
> +       case "tcp4", "tcp6":
> +               stype = syscall.SOCK_STREAM
> +       case "udp4", "udp6":
> +               stype = syscall.SOCK_DGRAM
> +       }
> +       hints := syscall.AddrinfoW{
> +               Family:   syscall.AF_UNSPEC,
> +               Socktype: stype,
> +               Protocol: syscall.IPPROTO_IP,
> +       }
> +       var result *syscall.AddrinfoW
> +       e := syscall.GetAddrInfoW(nil, syscall.StringToUTF16Ptr(**service),
> &hints, &result)
> +       if e != nil {
> +               return 0, os.NewSyscallError("**GetAddrInfoW", e)
> +       }
> +       defer syscall.FreeAddrInfoW(result)
> +       if result == nil {
> +               return 0, os.NewSyscallError("**LookupPort",
> syscall.EINVAL)
> +       }
> +       addr := unsafe.Pointer(result.Addr)
> +       switch result.Family {
> +       case syscall.AF_INET:
> +               a := (*syscall.RawSockaddrInet4)(**addr)
> +               return int(syscall.Ntohs(a.Port)), nil
> +       case syscall.AF_INET6:
> +               a := (*syscall.RawSockaddrInet6)(**addr)
> +               return int(syscall.Ntohs(a.Port)), nil
> +       }
> +       return 0, os.NewSyscallError("**LookupPort", syscall.EINVAL)
> +}
> +
>  func lookupCNAME(name string) (cname string, err error) {
>         var r *syscall.DNSRecord
>         e := syscall.DnsQuery(name, syscall.DNS_TYPE_CNAME, 0, nil, &r,
> nil)
> Index: src/pkg/net/port_test.go
> ==============================**==============================**=======
> --- a/src/pkg/net/port_test.go
> +++ b/src/pkg/net/port_test.go
> @@ -46,7 +46,7 @@
>         for i := 0; i < len(porttests); i++ {
>                 tt := porttests[i]
>                 if port, err := LookupPort(tt.netw, tt.name); port !=
> tt.port || (err == nil) != tt.ok {
> -                       t.Errorf("LookupPort(%q, %q) = %v, %s; want %v",
> +                       t.Errorf("LookupPort(%q, %q) = %v, %v; want %v",
>                                 tt.netw, tt.name, port, err, tt.port)
>                 }
>         }
>
>
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>

[brainman, 2013-02-02 01:24:24]

*** Submitted as https://code.google.com/p/go/source/detail?r=6f83f5d348ee ***

net: use windows GetAddrInfoW in LookupPort when possible

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/7252045