netstat

Documentation

Overview

Package netstat provides primitives for getting socket information on a Linux based operating system.

Index

• Variables
• func NoopFilter(*SockTabEntry) bool
• type AcceptFn
• type EnableFeatures
• type SkState
  • func (s SkState) String() string
• type SockEndpoint
  • func (s *SockEndpoint) String() string
• type SockTabEntry
  • func Netstat(ctx context.Context, feature EnableFeatures, fn AcceptFn) ([]SockTabEntry, error)
• type TimerActive
  • func (t TimerActive) String() string

Variables

var TimerActives = [...]string{
	"Off",
	"On",
	"KeepAlive",
	"TimeWait",
	"ProbeTimer",
}

Functions

func NoopFilter

func NoopFilter(*SockTabEntry) bool

NoopFilter - a test function returning true for all elements

Types

type AcceptFn

type AcceptFn func(*SockTabEntry) bool

AcceptFn is used to filter socket entries. The value returned indicates whether the element is to be appended to the socket list.

type EnableFeatures

type EnableFeatures struct {
	// TCP sockets and connections
	TCP bool
	// TCP6 (ipv6) sockets and connections
	TCP6 bool
	// UDP sockets and connections
	UDP bool
	// UDP6 (ipv6) sockets and connections
	UDP6 bool
	// UDP-Lite sockets and connections
	UDPLite bool
	// UDP-Lite6 (ipv6) sockets and connections
	UDPLite6 bool
	// Raw sockets and connections
	Raw bool
	// Raw6 (ipv6) sockets and connections
	Raw6 bool
	// Processes and Programs using sockets
	PID bool
	// Disable host network namespace
	NoHostNetwork bool
	// All network namespaces
	AllNetNs bool
	// Network namespace names using sockets and connections
	NetNsName []string
	// Network namespace PIDs using sockets and connections
	NetNsPids []uint32
}

type SkState

type SkState uint8

SkState type represents socket connection state

const (
	Established SkState = iota + 1
	SynSent
	SynRecv
	FinWait1
	FinWait2
	TimeWait
	Close
	CloseWait
	LastAck
	Listen
	Closing
)

Socket states

func (SkState) String

func (s SkState) String() string

type SockEndpoint

type SockEndpoint struct {
	IP   net.IP
	Port uint16
}

SockEndpoint represents an ip:port pair

func (*SockEndpoint) String

func (s *SockEndpoint) String() string

type SockTabEntry

type SockTabEntry struct {
	// Layer4 protocol, tcp, tcp6, udp or udp6
	Transport string
	// Local IPv4 address + Port
	LocalEndpoint *SockEndpoint
	// Remote IPv4 address + Port
	RemoteEndpoint *SockEndpoint
	// connection state
	State SkState
	// transmit-queue
	TxQueue uint64
	// receive-queue
	RxQueue uint64
	// timer_active
	Tr TimerActive
	// number of jiffies until timer expires
	TimerWhen uint64
	// number of unrecovered RTO Retransmission Timeouts
	Retrnsmt uint64
	// user ID
	UID uint32
	// unanswered 0-window probes
	Timeout uint64
	// inode
	Inode uint64
	// socket reference count
	Ref uint64
	// location of socket in memory
	Pointer uint64
	Process *common.Process
	NetNS   string
}

SockTabEntry type represents each line of the /proc/net/[tcp|udp] Kernel >=5.15

func Netstat

func Netstat(ctx context.Context, feature EnableFeatures, fn AcceptFn) ([]SockTabEntry, error)

Netstat - collect information about network port status

type TimerActive

type TimerActive uint8

TimerActive represents the state of the socket timer

const (
	Off           TimerActive = 0x00
	On            TimerActive = 0x01
	KeepAlive     TimerActive = 0x02
	TimeWaitTimer TimerActive = 0x03 // Unsure how to call this
	ProbeTimer    TimerActive = 0x04 // Unsure how to call this
)

socket timer states

func (TimerActive) String

func (t TimerActive) String() string