iptables

Documentation

Overview

Package iptables provides an interface and implementations for running iptables commands.

Index

• Constants
• func GetChainLines(table Table, save []byte) map[Chain]string
• func IsNotFoundError(err error) bool
• func MakeChainLine(chain Chain) string
• func ReadLine(readIndex int, byteArray []byte) (string, int)
• type Chain
• type FlushFlag
• type Interface
  • func New(exec utilexec.Interface, dbus utildbus.Interface, protocol Protocol) Interface
• type Protocol
• type RestoreCountersFlag
• type RulePosition
• type Table

Constants

const MinCheckVersion = "1.4.11"

Versions of iptables less than this do not support the -C / --check flag (test whether a rule exists).

const MinWait2Version = "1.4.22"

const MinWaitVersion = "1.4.20"

Minimum iptables versions supporting the -w and -w2 flags

Functions

func GetChainLines

func GetChainLines(table Table, save []byte) map[Chain]string

GetChainLines parses a table's iptables-save data to find chains in the table. It returns a map of iptables.Chain to string where the string is the chain line from the save (with counters etc).

func IsNotFoundError

func IsNotFoundError(err error) bool

IsNotFoundError returns true if the error indicates "not found". It parses the error string looking for known values, which is imperfect but works in practice.

func MakeChainLine

func MakeChainLine(chain Chain) string

MakeChainLine return an iptables-save/restore formatted chain line given a Chain

func ReadLine

func ReadLine(readIndex int, byteArray []byte) (string, int)

Types

type Chain

type Chain string

const (
	ChainPostrouting Chain = "POSTROUTING"
	ChainPrerouting  Chain = "PREROUTING"
	ChainOutput      Chain = "OUTPUT"
	ChainInput       Chain = "INPUT"
)

type FlushFlag

type FlushFlag bool

Option flag for Flush

const FlushTables FlushFlag = true

const NoFlushTables FlushFlag = false

type Interface

type Interface interface {
	// GetVersion returns the "X.Y.Z" semver string for iptables.
	GetVersion() (string, error)
	// EnsureChain checks if the specified chain exists and, if not, creates it.  If the chain existed, return true.
	EnsureChain(table Table, chain Chain) (bool, error)
	// FlushChain clears the specified chain.  If the chain did not exist, return error.
	FlushChain(table Table, chain Chain) error
	// DeleteChain deletes the specified chain.  If the chain did not exist, return error.
	DeleteChain(table Table, chain Chain) error
	// EnsureRule checks if the specified rule is present and, if not, creates it.  If the rule existed, return true.
	EnsureRule(position RulePosition, table Table, chain Chain, args ...string) (bool, error)
	// DeleteRule checks if the specified rule is present and, if so, deletes it.
	DeleteRule(table Table, chain Chain, args ...string) error
	// IsIpv6 returns true if this is managing ipv6 tables
	IsIpv6() bool
	// TODO: (BenTheElder) Unit-Test Save/SaveAll, Restore/RestoreAll
	// Save calls `iptables-save` for table.
	Save(table Table) ([]byte, error)
	// SaveAll calls `iptables-save`.
	SaveAll() ([]byte, error)
	// Restore runs `iptables-restore` passing data through []byte.
	// table is the Table to restore
	// data should be formatted like the output of Save()
	// flush sets the presence of the "--noflush" flag. see: FlushFlag
	// counters sets the "--counters" flag. see: RestoreCountersFlag
	Restore(table Table, data []byte, flush FlushFlag, counters RestoreCountersFlag) error
	// RestoreAll is the same as Restore except that no table is specified.
	RestoreAll(data []byte, flush FlushFlag, counters RestoreCountersFlag) error
	// AddReloadFunc adds a function to call on iptables reload
	AddReloadFunc(reloadFunc func())
	// Destroy cleans up resources used by the Interface
	Destroy()
}

An injectable interface for running iptables commands. Implementations must be goroutine-safe.

func New

func New(exec utilexec.Interface, dbus utildbus.Interface, protocol Protocol) Interface

New returns a new Interface which will exec iptables.

type Protocol

type Protocol byte

const (
	ProtocolIpv4 Protocol = iota + 1
	ProtocolIpv6
)

type RestoreCountersFlag

type RestoreCountersFlag bool

Option flag for Restore

const NoRestoreCounters RestoreCountersFlag = false

const RestoreCounters RestoreCountersFlag = true

type RulePosition

type RulePosition string

const (
	Prepend RulePosition = "-I"
	Append  RulePosition = "-A"
)

type Table

type Table string

const (
	TableNAT    Table = "nat"
	TableFilter Table = "filter"
)