telegraf/plugins/inputs/iptables/iptables.go

139 lines
3.9 KiB
Go

// +build linux
package iptables
import (
"errors"
"os/exec"
"regexp"
"strconv"
"strings"
"github.com/influxdata/telegraf"
"github.com/influxdata/telegraf/plugins/inputs"
)
// Iptables is a telegraf plugin to gather packets and bytes throughput from Linux's iptables packet filter.
type Iptables struct {
UseSudo bool
UseLock bool
Table string
Chains []string
lister chainLister
}
// Description returns a short description of the plugin.
func (ipt *Iptables) Description() string {
return "Gather packets and bytes throughput from iptables"
}
// SampleConfig returns sample configuration options.
func (ipt *Iptables) SampleConfig() string {
return `
## iptables require root access on most systems.
## Setting 'use_sudo' to true will make use of sudo to run iptables.
## Users must configure sudo to allow telegraf user to run iptables with no password.
## iptables can be restricted to only list command "iptables -nvL".
use_sudo = false
## Setting 'use_lock' to true runs iptables with the "-w" option.
## Adjust your sudo settings appropriately if using this option ("iptables -wnvl")
use_lock = false
## defines the table to monitor:
table = "filter"
## defines the chains to monitor.
## NOTE: iptables rules without a comment will not be monitored.
## Read the plugin documentation for more information.
chains = [ "INPUT" ]
`
}
// Gather gathers iptables packets and bytes throughput from the configured tables and chains.
func (ipt *Iptables) Gather(acc telegraf.Accumulator) error {
if ipt.Table == "" || len(ipt.Chains) == 0 {
return nil
}
// best effort : we continue through the chains even if an error is encountered,
// but we keep track of the last error.
var err error
for _, chain := range ipt.Chains {
data, e := ipt.lister(ipt.Table, chain)
if e != nil {
err = e
continue
}
e = ipt.parseAndGather(data, acc)
if e != nil {
err = e
continue
}
}
return err
}
func (ipt *Iptables) chainList(table, chain string) (string, error) {
iptablePath, err := exec.LookPath("iptables")
if err != nil {
return "", err
}
var args []string
name := iptablePath
if ipt.UseSudo {
name = "sudo"
args = append(args, iptablePath)
}
iptablesBaseArgs := "-nvL"
if ipt.UseLock {
iptablesBaseArgs = "-wnvL"
}
args = append(args, iptablesBaseArgs, chain, "-t", table, "-x")
c := exec.Command(name, args...)
out, err := c.Output()
return string(out), err
}
const measurement = "iptables"
var errParse = errors.New("Cannot parse iptables list information")
var chainNameRe = regexp.MustCompile(`^Chain\s+(\S+)`)
var fieldsHeaderRe = regexp.MustCompile(`^\s*pkts\s+bytes\s+`)
var valuesRe = regexp.MustCompile(`^\s*([0-9]+)\s+([0-9]+)\s+.*?(/\*\s(.*)\s\*/)?$`)
func (ipt *Iptables) parseAndGather(data string, acc telegraf.Accumulator) error {
lines := strings.Split(data, "\n")
if len(lines) < 3 {
return nil
}
mchain := chainNameRe.FindStringSubmatch(lines[0])
if mchain == nil {
return errParse
}
if !fieldsHeaderRe.MatchString(lines[1]) {
return errParse
}
for _, line := range lines[2:] {
mv := valuesRe.FindAllStringSubmatch(line, -1)
// best effort : if line does not match or rule is not commented forget about it
if len(mv) == 0 || len(mv[0]) != 5 || mv[0][4] == "" {
continue
}
tags := map[string]string{"table": ipt.Table, "chain": mchain[1], "ruleid": mv[0][4]}
fields := make(map[string]interface{})
// since parse error is already catched by the regexp,
// we never enter ther error case here => no error check (but still need a test to cover the case)
fields["pkts"], _ = strconv.ParseUint(mv[0][1], 10, 64)
fields["bytes"], _ = strconv.ParseUint(mv[0][2], 10, 64)
acc.AddFields(measurement, fields, tags)
}
return nil
}
type chainLister func(table, chain string) (string, error)
func init() {
inputs.Add("iptables", func() telegraf.Input {
ipt := new(Iptables)
ipt.lister = ipt.chainList
return ipt
})
}