Use 64-bit Darwin netstat counters (#1319)

Avoid 32-bit counter rollovers.

Signed-off-by: Ben Kochie <superq@gmail.com>

CHANGELOG.md

@@ -25,6 +25,7 @@
 * [CHANGE] Split cpufreq metrics into a separate collector #1253
 * [ENHANCEMENT] Add Infiniband counters #1120
 * [ENHANCEMENT] Move network_up labels into new metric network_info #1236
+* [ENHANCEMENT] Use 64-bit counters for Darwin netstat
 * [FEATURE] Add a flag to disable exporter metrics #1148
 * [FEATURE] Add kstat-based Solaris metrics for boottime, cpu and zfs collectors #1197
 * [FEATURE] Add uname collector for FreeBSD #1239

collector/netdev_darwin.go

@@ -16,52 +16,101 @@
 package collector
 
 import (
+	"bytes"
+	"encoding/binary"
 	"errors"
+	"net"
 	"regexp"
 	"strconv"
 
 	"github.com/prometheus/common/log"
+	"golang.org/x/sys/unix"
 )
 
-/*
-#include <stdio.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <ifaddrs.h>
-#include <net/if.h>
-*/
-import "C"
-
 func getNetDevStats(ignore *regexp.Regexp) (map[string]map[string]string, error) {
 	netDev := map[string]map[string]string{}
 
-	var ifap, ifa *C.struct_ifaddrs
-	if C.getifaddrs(&ifap) == -1 {
-		return nil, errors.New("getifaddrs() failed")
+	ifs, err := net.Interfaces()
+	if err != nil {
+		return nil, errors.New("net.Interfaces() failed")
 	}
-	defer C.freeifaddrs(ifap)
 
-	for ifa = ifap; ifa != nil; ifa = ifa.ifa_next {
-		if ifa.ifa_addr.sa_family == C.AF_LINK {
-			dev := C.GoString(ifa.ifa_name)
-			if ignore.MatchString(dev) {
-				log.Debugf("Ignoring device: %s", dev)
-				continue
-			}
+	for _, iface := range ifs {
+		ifaceData, err := getIfaceData(iface.Index)
+		if err != nil {
+			log.Debugf("failed to load data for interface %q: %v", iface.Name, err)
+			continue
+		}
 
-			devStats := map[string]string{}
-			data := (*C.struct_if_data)(ifa.ifa_data)
-			devStats["receive_packets"] = strconv.FormatUint(uint64(data.ifi_ipackets), 10)
-			devStats["transmit_packets"] = strconv.FormatUint(uint64(data.ifi_opackets), 10)
-			devStats["receive_errs"] = strconv.FormatUint(uint64(data.ifi_ierrors), 10)
-			devStats["transmit_errs"] = strconv.FormatUint(uint64(data.ifi_oerrors), 10)
-			devStats["receive_bytes"] = strconv.FormatUint(uint64(data.ifi_ibytes), 10)
-			devStats["transmit_bytes"] = strconv.FormatUint(uint64(data.ifi_obytes), 10)
-			devStats["receive_multicast"] = strconv.FormatUint(uint64(data.ifi_imcasts), 10)
-			devStats["transmit_multicast"] = strconv.FormatUint(uint64(data.ifi_omcasts), 10)
-			netDev[dev] = devStats
+		if ignore.MatchString(iface.Name) {
+			log.Debugf("Ignoring device: %s", iface.Name)
+			continue
 		}
+
+		devStats := map[string]string{}
+		devStats["receive_packets"] = strconv.FormatUint(ifaceData.Data.Ipackets, 10)
+		devStats["transmit_packets"] = strconv.FormatUint(ifaceData.Data.Opackets, 10)
+		devStats["receive_errs"] = strconv.FormatUint(ifaceData.Data.Ierrors, 10)
+		devStats["transmit_errs"] = strconv.FormatUint(ifaceData.Data.Oerrors, 10)
+		devStats["receive_bytes"] = strconv.FormatUint(ifaceData.Data.Ibytes, 10)
+		devStats["transmit_bytes"] = strconv.FormatUint(ifaceData.Data.Obytes, 10)
+		devStats["receive_multicast"] = strconv.FormatUint(ifaceData.Data.Imcasts, 10)
+		devStats["transmit_multicast"] = strconv.FormatUint(ifaceData.Data.Omcasts, 10)
+		netDev[iface.Name] = devStats
 	}
 
 	return netDev, nil
 }
+
+func getIfaceData(index int) (*ifMsghdr2, error) {
+	var data ifMsghdr2
+	rawData, err := unix.SysctlRaw("net", unix.AF_ROUTE, 0, 0, unix.NET_RT_IFLIST2, index)
+	if err != nil {
+		return nil, err
+	}
+	err = binary.Read(bytes.NewReader(rawData), binary.LittleEndian, &data)
+	return &data, err
+}
+
+type ifMsghdr2 struct {
+	Msglen    uint16
+	Version   uint8
+	Type      uint8
+	Addrs     int32
+	Flags     int32
+	Index     uint16
+	_         [2]byte
+	SndLen    int32
+	SndMaxlen int32
+	SndDrops  int32
+	Timer     int32
+	Data      ifData64
+}
+
+type ifData64 struct {
+	Type       uint8
+	Typelen    uint8
+	Physical   uint8
+	Addrlen    uint8
+	Hdrlen     uint8
+	Recvquota  uint8
+	Xmitquota  uint8
+	Unused1    uint8
+	Mtu        uint32
+	Metric     uint32
+	Baudrate   uint64
+	Ipackets   uint64
+	Ierrors    uint64
+	Opackets   uint64
+	Oerrors    uint64
+	Collisions uint64
+	Ibytes     uint64
+	Obytes     uint64
+	Imcasts    uint64
+	Omcasts    uint64
+	Iqdrops    uint64
+	Noproto    uint64
+	Recvtiming uint32
+	Xmittiming uint32
+	Lastchange unix.Timeval32
+}