Source: ipvs.go in package github.com/prometheus/procfs

Copyright 2018 The Prometheus Authors Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.


package procfs

import (
	"bufio"
	"bytes"
	"encoding/hex"
	"errors"
	"fmt"
	"io"
	"io/ioutil"
	"net"
	"os"
	"strconv"
	"strings"

	"github.com/prometheus/procfs/internal/util"
)

IPVSStats holds IPVS statistics, as exposed by the kernel in `/proc/net/ip_vs_stats`.

Total count of connections.

Total incoming packages processed.

Total outgoing packages processed.

Total incoming traffic.

Total outgoing traffic.

	OutgoingBytes uint64
}

IPVSBackendStatus holds current metrics of one virtual / real address pair.

The local (virtual) IP address.

The remote (real) IP address.

The local (virtual) port.

The remote (real) port.

The local firewall mark

The transport protocol (TCP, UDP).

The current number of active connections for this virtual/real address pair.

The current number of inactive connections for this virtual/real address pair.

The current weight of this virtual/real address pair.

	Weight uint64
}

IPVSStats reads the IPVS statistics from the specified `proc` filesystem.

func (fs FS) IPVSStats() (IPVSStats, error) {
	data, err := util.ReadFileNoStat(fs.proc.Path("net/ip_vs_stats"))
	if err != nil {
		return IPVSStats{}, err
	}

	return parseIPVSStats(bytes.NewReader(data))
}

parseIPVSStats performs the actual parsing of `ip_vs_stats`.

func parseIPVSStats(r io.Reader) (IPVSStats, error) {
	var (
		statContent []byte
		statLines   []string
		statFields  []string
		stats       IPVSStats
	)

	statContent, err := ioutil.ReadAll(r)
	if err != nil {
		return IPVSStats{}, err
	}

	statLines = strings.SplitN(string(statContent), "\n", 4)
	if len(statLines) != 4 {
		return IPVSStats{}, errors.New("ip_vs_stats corrupt: too short")
	}

	statFields = strings.Fields(statLines[2])
	if len(statFields) != 5 {
		return IPVSStats{}, errors.New("ip_vs_stats corrupt: unexpected number of fields")
	}

	stats.Connections, err = strconv.ParseUint(statFields[0], 16, 64)
	if err != nil {
		return IPVSStats{}, err
	}
	stats.IncomingPackets, err = strconv.ParseUint(statFields[1], 16, 64)
	if err != nil {
		return IPVSStats{}, err
	}
	stats.OutgoingPackets, err = strconv.ParseUint(statFields[2], 16, 64)
	if err != nil {
		return IPVSStats{}, err
	}
	stats.IncomingBytes, err = strconv.ParseUint(statFields[3], 16, 64)
	if err != nil {
		return IPVSStats{}, err
	}
	stats.OutgoingBytes, err = strconv.ParseUint(statFields[4], 16, 64)
	if err != nil {
		return IPVSStats{}, err
	}

	return stats, nil
}

IPVSBackendStatus reads and returns the status of all (virtual,real) server pairs from the specified `proc` filesystem.

func (fs FS) IPVSBackendStatus() ([]IPVSBackendStatus, error) {
	file, err := os.Open(fs.proc.Path("net/ip_vs"))
	if err != nil {
		return nil, err
	}
	defer file.Close()

	return parseIPVSBackendStatus(file)
}

func parseIPVSBackendStatus(file io.Reader) ([]IPVSBackendStatus, error) {
	var (
		status       []IPVSBackendStatus
		scanner      = bufio.NewScanner(file)
		proto        string
		localMark    string
		localAddress net.IP
		localPort    uint16
		err          error
	)

	for scanner.Scan() {
		fields := strings.Fields(scanner.Text())
		if len(fields) == 0 {
			continue
		}
		switch {
		case fields[0] == "IP" || fields[0] == "Prot" || fields[1] == "RemoteAddress:Port":
			continue
		case fields[0] == "TCP" || fields[0] == "UDP":
			if len(fields) < 2 {
				continue
			}
			proto = fields[0]
			localMark = ""
			localAddress, localPort, err = parseIPPort(fields[1])
			if err != nil {
				return nil, err
			}
		case fields[0] == "FWM":
			if len(fields) < 2 {
				continue
			}
			proto = fields[0]
			localMark = fields[1]
			localAddress = nil
			localPort = 0
		case fields[0] == "->":
			if len(fields) < 6 {
				continue
			}
			remoteAddress, remotePort, err := parseIPPort(fields[1])
			if err != nil {
				return nil, err
			}
			weight, err := strconv.ParseUint(fields[3], 10, 64)
			if err != nil {
				return nil, err
			}
			activeConn, err := strconv.ParseUint(fields[4], 10, 64)
			if err != nil {
				return nil, err
			}
			inactConn, err := strconv.ParseUint(fields[5], 10, 64)
			if err != nil {
				return nil, err
			}
			status = append(status, IPVSBackendStatus{
				LocalAddress:  localAddress,
				LocalPort:     localPort,
				LocalMark:     localMark,
				RemoteAddress: remoteAddress,
				RemotePort:    remotePort,
				Proto:         proto,
				Weight:        weight,
				ActiveConn:    activeConn,
				InactConn:     inactConn,
			})
		}
	}
	return status, nil
}

func parseIPPort(s string) (net.IP, uint16, error) {
	var (
		ip  net.IP
		err error
	)

	switch len(s) {
	case 13:
		ip, err = hex.DecodeString(s[0:8])
		if err != nil {
			return nil, 0, err
		}
	case 46:
		ip = net.ParseIP(s[1:40])
		if ip == nil {
			return nil, 0, fmt.Errorf("invalid IPv6 address: %s", s[1:40])
		}
	default:
		return nil, 0, fmt.Errorf("unexpected IP:Port: %s", s)
	}

	portString := s[len(s)-4:]
	if len(portString) != 4 {
		return nil, 0, fmt.Errorf("unexpected port string format: %s", portString)
	}
	port, err := strconv.ParseUint(portString, 16, 16)
	if err != nil {
		return nil, 0, err
	}

	return ip, uint16(port), nil