only run ifconfig/netstat if necessary, add some tests

net/net_darwin.go

@@ -4,108 +4,248 @@ package net
 
 import (
 	"errors"
+	"fmt"
 	"os/exec"
+	"regexp"
 	"strconv"
 	"strings"
 )
 
-// example of `netstat -ibdnWI lo0` output on yosemite
+var (
+	errNetstatHeader  = errors.New("Can't parse header of netstat output")
+	netstatLinkRegexp = regexp.MustCompile(`^<Link#(\d+)>$`)
+)
+
+const endOfLine = "\n"
+
+func parseNetstatLine(line string) (stat *IOCountersStat, linkId *uint, err error) {
+	var (
+		numericValue uint64
+		columns      = strings.Fields(line)
+	)
+
+	if columns[0] == "Name" {
+		err = errNetstatHeader
+		return
+	}
+
+	// try to extract the numeric value from <Link#123>
+	if subMatch := netstatLinkRegexp.FindStringSubmatch(columns[2]); len(subMatch) == 2 {
+		numericValue, err = strconv.ParseUint(subMatch[1], 10, 64)
+		if err != nil {
+			return
+		}
+		linkIdUint := uint(numericValue)
+		linkId = &linkIdUint
+	}
+
+	base := 1
+	numberColumns := len(columns)
+	// sometimes Address is ommitted
+	if numberColumns < 12 {
+		base = 0
+	}
+	if numberColumns < 11 || numberColumns > 13 {
+		err = fmt.Errorf("Line %q do have an invalid number of columns %d", line, numberColumns)
+		return
+	}
+
+	parsed := make([]uint64, 0, 7)
+	vv := []string{
+		columns[base+3], // Ipkts == PacketsRecv
+		columns[base+4], // Ierrs == Errin
+		columns[base+5], // Ibytes == BytesRecv
+		columns[base+6], // Opkts == PacketsSent
+		columns[base+7], // Oerrs == Errout
+		columns[base+8], // Obytes == BytesSent
+	}
+	if len(columns) == 12 {
+		vv = append(vv, columns[base+10])
+	}
+
+	for _, target := range vv {
+		if target == "-" {
+			parsed = append(parsed, 0)
+			continue
+		}
+
+		if numericValue, err = strconv.ParseUint(target, 10, 64); err != nil {
+			return
+		}
+		parsed = append(parsed, numericValue)
+	}
+
+	stat = &IOCountersStat{
+		Name:        strings.Trim(columns[0], "*"), // remove the * that sometimes is on right on interface
+		PacketsRecv: parsed[0],
+		Errin:       parsed[1],
+		BytesRecv:   parsed[2],
+		PacketsSent: parsed[3],
+		Errout:      parsed[4],
+		BytesSent:   parsed[5],
+	}
+	if len(parsed) == 7 {
+		stat.Dropout = parsed[6]
+	}
+	return
+}
+
+type netstatInterface struct {
+	linkId *uint
+	stat   *IOCountersStat
+}
+
+func parseNetstatOutput(output string) ([]netstatInterface, error) {
+	var (
+		err   error
+		lines = strings.Split(strings.Trim(output, endOfLine), endOfLine)
+	)
+
+	// number of interfaces is number of lines less one for the header
+	numberInterfaces := len(lines) - 1
+
+	interfaces := make([]netstatInterface, numberInterfaces)
+	// no output beside header
+	if numberInterfaces == 0 {
+		return interfaces, nil
+	}
+
+	for index := 0; index < numberInterfaces; index++ {
+		nsIface := netstatInterface{}
+		if nsIface.stat, nsIface.linkId, err = parseNetstatLine(lines[index+1]); err != nil {
+			return nil, err
+		}
+		interfaces[index] = nsIface
+	}
+	return interfaces, nil
+}
+
+// map that hold the name of a network interface and the number of usage
+type mapInterfaceNameUsage map[string]uint
+
+func newMapInterfaceNameUsage(ifaces []netstatInterface) mapInterfaceNameUsage {
+	output := make(mapInterfaceNameUsage)
+	for index := range ifaces {
+		if ifaces[index].linkId != nil {
+			ifaceName := ifaces[index].stat.Name
+			usage, ok := output[ifaceName]
+			if ok {
+				output[ifaceName] = usage + 1
+			} else {
+				output[ifaceName] = 1
+			}
+		}
+	}
+	return output
+}
+
+func (min mapInterfaceNameUsage) isTruncated() bool {
+	for _, usage := range min {
+		if usage > 1 {
+			return true
+		}
+	}
+	return false
+}
+
+func (min mapInterfaceNameUsage) notTruncated() []string {
+	output := make([]string, 0)
+	for ifaceName, usage := range min {
+		if usage == 1 {
+			output = append(output, ifaceName)
+		}
+	}
+	return output
+}
+
+// example of `netstat -ibdnW` output on yosemite
 // Name  Mtu   Network       Address            Ipkts Ierrs     Ibytes    Opkts Oerrs     Obytes  Coll Drop
 // lo0   16384 <Link#1>                        869107     0  169411755   869107     0  169411755     0   0
 // lo0   16384 ::1/128     ::1                 869107     -  169411755   869107     -  169411755     -   -
 // lo0   16384 127           127.0.0.1         869107     -  169411755   869107     -  169411755     -   -
 func IOCounters(pernic bool) ([]IOCountersStat, error) {
-	const endOfLine = "\n"
-	// example of `ifconfig -l` output on yosemite:
-	// lo0 gif0 stf0 en0 p2p0 awdl0
-	ifconfig, err := exec.LookPath("/sbin/ifconfig")
+	var (
+		ret      []IOCountersStat
+		retIndex int
+	)
+
+	netstat, err := exec.LookPath("/usr/sbin/netstat")
 	if err != nil {
 		return nil, err
 	}
 
-	netstat, err := exec.LookPath("/usr/sbin/netstat")
+	// try to get all interface metrics, and hope there won't be any truncated
+	out, err := invoke.Command(netstat, "-ibdnW")
 	if err != nil {
 		return nil, err
 	}
 
-	// list all interfaces
-	out, err := invoke.Command(ifconfig, "-l")
+	nsInterfaces, err := parseNetstatOutput(string(out))
 	if err != nil {
 		return nil, err
 	}
-	interfaces := strings.Fields(strings.TrimRight(string(out), endOfLine))
-	ret := make([]IOCountersStat, 0)
 
-	// extract metrics for all interfaces
-	for _, interfaceName := range interfaces {
-		if out, err = invoke.Command(netstat, "-ibdnWI" + interfaceName); err != nil {
-			return nil, err
-		}
-		lines := strings.Split(string(out), endOfLine)
-		if len(lines) <= 1 {
-			// invalid output
-			continue
-		}
+	ifaceUsage := newMapInterfaceNameUsage(nsInterfaces)
+	notTruncated := ifaceUsage.notTruncated()
+	ret = make([]IOCountersStat, len(notTruncated))
 
-		if len(lines[1]) == 0 {
-			// interface had been removed since `ifconfig -l` had been executed
-			continue
-		}
-
-		// only the first output is fine
-		values := strings.Fields(lines[1])
-
-		base := 1
-		// sometimes Address is ommitted
-		if len(values) < 12 {
-			base = 0
+	if !ifaceUsage.isTruncated() {
+		// no truncated interface name, return stats of all interface with <Link#...>
+		for index := range nsInterfaces {
+			if nsInterfaces[index].linkId != nil {
+				ret[retIndex] = *nsInterfaces[index].stat
+				retIndex++
+			}
 		}
-
-		parsed := make([]uint64, 0, 7)
-		vv := []string{
-			values[base+3], // Ipkts == PacketsRecv
-			values[base+4], // Ierrs == Errin
-			values[base+5], // Ibytes == BytesRecv
-			values[base+6], // Opkts == PacketsSent
-			values[base+7], // Oerrs == Errout
-			values[base+8], // Obytes == BytesSent
+	} else {
+		// duplicated interface, list all interfaces
+		ifconfig, err := exec.LookPath("/sbin/ifconfig")
+		if err != nil {
+			return nil, err
 		}
-		if len(values) == 12 {
-			vv = append(vv, values[base+10])
+		if out, err = invoke.Command(ifconfig, "-l"); err != nil {
+			return nil, err
 		}
+		interfaceNames := strings.Fields(strings.TrimRight(string(out), endOfLine))
 
-		for _, target := range vv {
-			if target == "-" {
-				parsed = append(parsed, 0)
-				continue
+		// for each of the interface name, run netstat if we don't have any stats yet
+		for _, interfaceName := range interfaceNames {
+			truncated := true
+			for index := range nsInterfaces {
+				if nsInterfaces[index].linkId != nil && nsInterfaces[index].stat.Name == interfaceName {
+					// handle the non truncated name to avoid execute netstat for them again
+					ret[retIndex] = *nsInterfaces[index].stat
+					retIndex++
+					truncated = false
+					break
+				}
 			}
-
-			t, err := strconv.ParseUint(target, 10, 64)
-			if err != nil {
-				return nil, err
+			if truncated {
+				// run netstat with -I$ifacename
+				if out, err = invoke.Command(netstat, "-ibdnWI" + interfaceName);err != nil {
+					return nil, err
+				}
+				parsedIfaces, err := parseNetstatOutput(string(out))
+				if err != nil {
+					return nil, err
+				}
+				if len(parsedIfaces) == 0 {
+					// interface had been removed since `ifconfig -l` had been executed
+					continue
+				}
+				for index := range parsedIfaces {
+					if parsedIfaces[index].linkId != nil {
+						ret = append(ret, *parsedIfaces[index].stat)
+						break
+					}
+				}
 			}
-			parsed = append(parsed, t)
 		}
-
-		n := IOCountersStat{
-			Name:        interfaceName,
-			PacketsRecv: parsed[0],
-			Errin:       parsed[1],
-			BytesRecv:   parsed[2],
-			PacketsSent: parsed[3],
-			Errout:      parsed[4],
-			BytesSent:   parsed[5],
-		}
-		if len(parsed) == 7 {
-			n.Dropout = parsed[6]
-		}
-		ret = append(ret, n)
 	}
 
 	if pernic == false {
 		return getIOCountersAll(ret)
 	}
-
 	return ret, nil
 }
 

net/net_darwin_test.go

@@ -0,0 +1,140 @@
+package net
+
+import (
+	"testing"
+
+	assert "github.com/stretchr/testify/require"
+)
+
+const (
+	netstatTruncated = `Name  Mtu   Network       Address            Ipkts Ierrs     Ibytes    Opkts Oerrs     Obytes  Coll Drop
+lo0   16384 <Link#1>                         31241     0    3769823    31241     0    3769823     0   0
+lo0   16384 ::1/128     ::1                  31241     -    3769823    31241     -    3769823     -   -
+lo0   16384 127           127.0.0.1          31241     -    3769823    31241     -    3769823     -   -
+lo0   16384 fe80::1%lo0 fe80:1::1            31241     -    3769823    31241     -    3769823     -   -
+gif0* 1280  <Link#2>                             0     0          0        0     0          0     0   0
+stf0* 1280  <Link#3>                             0     0          0        0     0          0     0   0
+utun8 1500  <Link#88>                          286     0      27175        0     0          0     0   0
+utun8 1500  <Link#90>                          286     0      29554        0     0          0     0   0
+utun8 1500  <Link#92>                          286     0      29244        0     0          0     0   0
+utun8 1500  <Link#93>                          286     0      28267        0     0          0     0   0
+utun8 1500  <Link#95>                          286     0      28593        0     0          0     0   0`
+	netstatNotTruncated  = `Name  Mtu   Network       Address            Ipkts Ierrs     Ibytes    Opkts Oerrs     Obytes  Coll Drop
+lo0   16384 <Link#1>                      27190978     0 12824763793 27190978     0 12824763793     0   0
+lo0   16384 ::1/128     ::1               27190978     - 12824763793 27190978     - 12824763793     -   -
+lo0   16384 127           127.0.0.1       27190978     - 12824763793 27190978     - 12824763793     -   -
+lo0   16384 fe80::1%lo0 fe80:1::1         27190978     - 12824763793 27190978     - 12824763793     -   -
+gif0* 1280  <Link#2>                             0     0          0        0     0          0     0   0
+stf0* 1280  <Link#3>                             0     0          0        0     0          0     0   0
+en0   1500  <Link#4>    a8:66:7f:dd:ee:ff  5708989     0 7295722068  3494252     0  379533492     0 230
+en0   1500  fe80::aa66: fe80:4::aa66:7fff  5708989     - 7295722068  3494252     -  379533492     -   -`
+)
+
+func TestparseNetstatLineHeader(t *testing.T) {
+	stat, linkIkd, err := parseNetstatLine(`Name  Mtu   Network       Address            Ipkts Ierrs     Ibytes    Opkts Oerrs     Obytes  Coll Drop`)
+	assert.Nil(t, linkIkd)
+	assert.Nil(t, stat)
+	assert.Error(t, err)
+	assert.Equal(t, errNetstatHeader, err)
+}
+
+func assertLoopbackStat(t *testing.T, err error, stat *IOCountersStat) {
+	assert.NoError(t, err)
+	assert.Equal(t, 869107, stat.PacketsRecv)
+	assert.Equal(t, 0, stat.Errin)
+	assert.Equal(t, 169411755, stat.BytesRecv)
+	assert.Equal(t,869108,  stat.PacketsSent)
+	assert.Equal(t, 1, stat.Errout)
+	assert.Equal(t, 169411756, stat.BytesSent)
+}
+
+func TestparseNetstatLineLink(t *testing.T) {
+	stat, linkId, err := parseNetstatLine(
+		`lo0   16384 <Link#1>                        869107     0  169411755   869108     1  169411756     0   0`,
+	)
+	assertLoopbackStat(t, err, stat)
+	assert.NotNil(t, linkId)
+	assert.Equal(t, uint(1), *linkId)
+}
+
+func TestparseNetstatLineIPv6(t *testing.T) {
+	stat, linkId, err := parseNetstatLine(
+		`lo0   16384 ::1/128     ::1                 869107     -  169411755   869108     1  169411756     -   -`,
+	)
+	assertLoopbackStat(t, err, stat)
+	assert.Nil(t, linkId)
+}
+
+func TestparseNetstatLineIPv4(t *testing.T) {
+	stat, linkId, err := parseNetstatLine(
+		`lo0   16384 127           127.0.0.1         869107     -  169411755   869108     1  169411756     -   -`,
+	)
+	assertLoopbackStat(t, err, stat)
+	assert.Nil(t, linkId)
+}
+
+func TestParseNetstatOutput(t *testing.T) {
+	nsInterfaces, err := parseNetstatOutput(netstatNotTruncated)
+	assert.NoError(t, err)
+	assert.Len(t, nsInterfaces, 8)
+	for index := range nsInterfaces {
+		assert.NotNil(t, nsInterfaces[index].stat, "Index %d", index)
+	}
+
+	assert.NotNil(t, nsInterfaces[0].linkId)
+	assert.Equal(t, uint(1), *nsInterfaces[0].linkId)
+
+	assert.Nil(t, nsInterfaces[1].linkId)
+	assert.Nil(t, nsInterfaces[2].linkId)
+	assert.Nil(t, nsInterfaces[3].linkId)
+
+	assert.NotNil(t, nsInterfaces[4].linkId)
+	assert.Equal(t, uint(2), *nsInterfaces[4].linkId)
+
+	assert.NotNil(t, nsInterfaces[5].linkId)
+	assert.Equal(t, uint(3), *nsInterfaces[5].linkId)
+
+	assert.NotNil(t, nsInterfaces[6].linkId)
+	assert.Equal(t,  uint(4), *nsInterfaces[6].linkId)
+
+	assert.Nil(t, nsInterfaces[7].linkId)
+
+	mapUsage := newMapInterfaceNameUsage(nsInterfaces)
+	assert.False(t, mapUsage.isTruncated())
+	assert.Len(t, mapUsage.notTruncated(), 4)
+}
+
+func TestParseNetstatTruncated(t *testing.T) {
+	nsInterfaces, err := parseNetstatOutput(netstatTruncated)
+	assert.NoError(t, err)
+	assert.Len(t, nsInterfaces, 11)
+	for index := range nsInterfaces {
+		assert.NotNil(t, nsInterfaces[index].stat, "Index %d", index)
+	}
+
+	const truncatedIface = "utun8"
+
+	assert.NotNil(t, nsInterfaces[6].linkId)
+	assert.Equal(t,  uint(88), *nsInterfaces[6].linkId)
+	assert.Equal(t, truncatedIface, nsInterfaces[6].stat.Name)
+
+	assert.NotNil(t, nsInterfaces[7].linkId)
+	assert.Equal(t,uint(90), *nsInterfaces[7].linkId)
+	assert.Equal(t, truncatedIface, nsInterfaces[7].stat.Name)
+
+	assert.NotNil(t, nsInterfaces[8].linkId)
+	assert.Equal(t, uint(92), *nsInterfaces[8].linkId )
+	assert.Equal(t, truncatedIface, nsInterfaces[8].stat.Name)
+
+	assert.NotNil(t, nsInterfaces[9].linkId)
+	assert.Equal(t, uint(93), *nsInterfaces[9].linkId )
+	assert.Equal(t, truncatedIface, nsInterfaces[9].stat.Name)
+
+	assert.NotNil(t, nsInterfaces[10].linkId)
+	assert.Equal(t, uint(95), *nsInterfaces[10].linkId )
+	assert.Equal(t, truncatedIface, nsInterfaces[10].stat.Name)
+
+	mapUsage := newMapInterfaceNameUsage(nsInterfaces)
+	assert.True(t, mapUsage.isTruncated())
+	assert.Equal(t, 3, len(mapUsage.notTruncated()), "en0, gif0 and stf0")
+}