From 855ec85dbc40c226db0b4888e5a004929e9f6ffa Mon Sep 17 00:00:00 2001
From: WAKAYAMA Shirou <shirou.faw@gmail.com>
Date: Fri, 16 May 2014 11:33:35 +0900
Subject: [PATCH] implement net_io_counters on Windows.

---
 common.go         | 24 ++++++++++++++++++++++
 common_windows.go | 11 ++++++++++
 net_windows.go    | 60 +++++++++++++++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 93 insertions(+), 2 deletions(-)

diff --git a/common.go b/common.go
index 9130303..4f05543 100644
--- a/common.go
+++ b/common.go
@@ -9,6 +9,7 @@ package gopsutil
 import (
 	"bufio"
 	"os"
+	"reflect"
 	"strconv"
 	"strings"
 )
@@ -77,3 +78,26 @@ func stringContains(target []string, src string) bool {
 	}
 	return false
 }
+
+// get struct attributes.
+// This method is used only for debugging platform dependent code.
+func attributes(m interface{}) map[string]reflect.Type {
+	typ := reflect.TypeOf(m)
+	if typ.Kind() == reflect.Ptr {
+		typ = typ.Elem()
+	}
+
+	attrs := make(map[string]reflect.Type)
+	if typ.Kind() != reflect.Struct {
+		return nil
+	}
+
+	for i := 0; i < typ.NumField(); i++ {
+		p := typ.Field(i)
+		if !p.Anonymous {
+			attrs[p.Name] = p.Type
+		}
+	}
+
+	return attrs
+}
diff --git a/common_windows.go b/common_windows.go
index 04fea1d..e84abc3 100644
--- a/common_windows.go
+++ b/common_windows.go
@@ -4,6 +4,7 @@ package gopsutil
 
 import (
 	"syscall"
+	"unsafe"
 )
 
 var (
@@ -18,3 +19,13 @@ type FILETIME struct {
 	DwLowDateTime  uint32
 	DwHighDateTime uint32
 }
+
+// borrowed from net/interface_windows.go
+func bytePtrToString(p *uint8) string {
+	a := (*[10000]uint8)(unsafe.Pointer(p))
+	i := 0
+	for a[i] != 0 {
+		i++
+	}
+	return string(a[:i])
+}
diff --git a/net_windows.go b/net_windows.go
index 329b544..c32f956 100644
--- a/net_windows.go
+++ b/net_windows.go
@@ -3,9 +3,65 @@
 package gopsutil
 
 import (
-	"errors"
+	"net"
+	"os"
+	"syscall"
+	"unsafe"
 )
 
 func NetIOCounters(pernic bool) ([]NetIOCountersStat, error) {
-	return nil, errors.New("not implemented yet")
+	ifs, err := net.Interfaces()
+	if err != nil {
+		return nil, err
+	}
+
+	ai, err := getAdapterList()
+	if err != nil {
+		return nil, err
+	}
+	var ret []NetIOCountersStat
+
+	for _, ifi := range ifs {
+		name := ifi.Name
+		for ; ai != nil; ai = ai.Next {
+			name = bytePtrToString(&ai.Description[0])
+			c := NetIOCountersStat{
+				Name: name,
+			}
+
+			row := syscall.MibIfRow{Index: ai.Index}
+			e := syscall.GetIfEntry(&row)
+			if e != nil {
+				return nil, os.NewSyscallError("GetIfEntry", e)
+			}
+			c.BytesSent = uint64(row.OutOctets)
+			c.BytesRecv = uint64(row.InOctets)
+			c.PacketsSent = uint64(row.OutUcastPkts)
+			c.PacketsRecv = uint64(row.InUcastPkts)
+			c.Errin = uint64(row.InErrors)
+			c.Errout = uint64(row.OutErrors)
+			c.Dropin = uint64(row.InDiscards)
+			c.Dropout = uint64(row.OutDiscards)
+
+			ret = append(ret, c)
+		}
+	}
+	return ret, nil
+}
+
+// borrowed from src/pkg/net/interface_windows.go
+func getAdapterList() (*syscall.IpAdapterInfo, error) {
+	b := make([]byte, 1000)
+	l := uint32(len(b))
+	a := (*syscall.IpAdapterInfo)(unsafe.Pointer(&b[0]))
+	err := syscall.GetAdaptersInfo(a, &l)
+	if err == syscall.ERROR_BUFFER_OVERFLOW {
+		b = make([]byte, l)
+		a = (*syscall.IpAdapterInfo)(unsafe.Pointer(&b[0]))
+		err = syscall.GetAdaptersInfo(a, &l)
+	}
+	if err != nil {
+		return nil, os.NewSyscallError("GetAdaptersInfo", err)
+	}
+	return a, nil
 }