netutil

Documentation

Overview

Package netutil contains network-related utilities common among dnsproxy packages.

TODO(a.garipov): Move improved versions of these into netutil in module golibs.

Index

• func DefaultHostsPaths() (paths []string, err error)
• func ListenConfig(l *slog.Logger) (lc *net.ListenConfig)
• func ParseSubnet(s string) (p netip.Prefix, err error)
• func UDPGetOOBSize() (oobSize int)
• func UDPRead(conn *net.UDPConn, buf []byte, udpOOBSize int) (n int, localIP netip.Addr, remoteAddr *net.UDPAddr, err error)
• func UDPSetOptions(c *net.UDPConn) (err error)
• func UDPWrite(data []byte, conn *net.UDPConn, remoteAddr *net.UDPAddr, localIP netip.Addr) (n int, err error)

Functions

func DefaultHostsPaths

func DefaultHostsPaths() (paths []string, err error)

DefaultHostsPaths returns the slice of default paths to system hosts files.

TODO(s.chzhen): Since [fs.FS] is no longer needed, update the hostsfile.DefaultHostsPaths from golibs.

func ListenConfig

func ListenConfig(l *slog.Logger) (lc *net.ListenConfig)

ListenConfig returns the default net.ListenConfig used by the plain-DNS servers in this module. l must not be nil.

TODO(a.garipov): Add tests.

TODO(a.garipov): Add an option to not set SO_REUSEPORT on Unix to prevent issues with OpenWrt.

See https://github.com/AdguardTeam/AdGuardHome/issues/5872.

TODO(a.garipov): DRY with AdGuard DNS when we can.

func ParseSubnet

func ParseSubnet(s string) (p netip.Prefix, err error)

ParseSubnet parses s either as a CIDR prefix itself, or as an IP address, returning the corresponding single-IP CIDR prefix.

TODO(e.burkov): Replace usages with netutil.Prefix.

func UDPGetOOBSize

func UDPGetOOBSize() (oobSize int)

UDPGetOOBSize returns maximum size of the received OOB data.

func UDPRead

func UDPRead(
	conn *net.UDPConn,
	buf []byte,
	udpOOBSize int,
) (n int, localIP netip.Addr, remoteAddr *net.UDPAddr, err error)

UDPRead reads the message from conn using buf and receives a control-message payload of size udpOOBSize from it. It returns the number of bytes copied into buf and the source address of the message.

TODO(s.chzhen): Consider using netip.Addr.

func UDPSetOptions

func UDPSetOptions(c *net.UDPConn) (err error)

UDPSetOptions sets flag options on a UDP socket to be able to receive the necessary OOB data.

func UDPWrite

func UDPWrite(
	data []byte,
	conn *net.UDPConn,
	remoteAddr *net.UDPAddr,
	localIP netip.Addr,
) (n int, err error)

UDPWrite writes the data to the remoteAddr using conn.

TODO(s.chzhen): Consider using netip.Addr.