aghnet

Documentation

Overview

Package aghnet contains some utilities for networking.

Index

• Constants
• func CanBindPort(port int) (can bool, err error)
• func CheckPacketPortAvailable(host net.IP, port int) error
• func CheckPortAvailable(host net.IP, port int) error
• func CollectAllIfacesAddrs() (addrs []string, err error)
• func ErrorIsAddrInUse(err error) bool
• func GatewayIP(ifaceName string) net.IP
• func GenerateHostname(ip net.IP) (hostname string)
• func GetInterfaceByIP(ip net.IP) string
• func GetSubnet(ifaceName string) *net.IPNet
• func IfaceHasStaticIP(ifaceName string) (has bool, err error)
• func IfaceSetStaticIP(ifaceName string) (err error)
• func IsValidHostOuterRune(r rune) (ok bool)
• func ReverseAddr(ip net.IP) (arpa string)
• func SplitHost(hostport string) (host string, err error)
• func UnreverseAddr(arpa string) (unreversed net.IP)
• func ValidateDomainName(name string) (err error)
• func ValidateDomainNameLabel(label string) (err error)
• func ValidateHardwareAddress(hwa net.HardwareAddr) (err error)
• type EtcHostsContainer
  • func (ehc *EtcHostsContainer) Close()
  • func (ehc *EtcHostsContainer) Init(hostsFn string)
  • func (ehc *EtcHostsContainer) List() (ipToHosts map[string][]string)
  • func (ehc *EtcHostsContainer) Process(host string, qtype uint16) []net.IP
  • func (ehc *EtcHostsContainer) ProcessReverse(addr string, qtype uint16) (hosts []string)
  • func (ehc *EtcHostsContainer) SetOnChanged(onChanged onChangedT)
  • func (ehc *EtcHostsContainer) Start()
• type HostGenFunc
• type NetInterface
  • func GetValidNetInterfacesForWeb() ([]*NetInterface, error)
  • func (iface *NetInterface) MarshalJSON() ([]byte, error)
• type SubnetDetector
  • func NewSubnetDetector() (snd *SubnetDetector, err error)
  • func (snd *SubnetDetector) IsLocallyServedNetwork(ip net.IP) (is bool)
  • func (snd *SubnetDetector) IsSpecialNetwork(ip net.IP) (is bool)
• type SystemResolvers
  • func NewSystemResolvers(refreshIvl time.Duration, hostGenFunc HostGenFunc) (sr SystemResolvers, err error)

Constants

const ErrNoStaticIPInfo agherr.Error = "no information about static ip"

ErrNoStaticIPInfo is returned by IfaceHasStaticIP when no information about the IP being static is available.

Functions

func CanBindPort

func CanBindPort(port int) (can bool, err error)

CanBindPort checks if we can bind to the given port.

func CheckPacketPortAvailable

func CheckPacketPortAvailable(host net.IP, port int) error

CheckPacketPortAvailable - check if UDP port is available

func CheckPortAvailable

func CheckPortAvailable(host net.IP, port int) error

CheckPortAvailable - check if TCP port is available

func CollectAllIfacesAddrs

func CollectAllIfacesAddrs() (addrs []string, err error)

CollectAllIfacesAddrs returns the slice of all network interfaces IP addresses without port number.

func ErrorIsAddrInUse

func ErrorIsAddrInUse(err error) bool

ErrorIsAddrInUse - check if error is "address already in use"

func GatewayIP

func GatewayIP(ifaceName string) net.IP

GatewayIP returns IP address of interface's gateway.

func GenerateHostname

func GenerateHostname(ip net.IP) (hostname string)

GenerateHostname generates the hostname from ip. In case of using IPv4 the result should be like:

192-168-10-1

In case of using IPv6, the result is like:

ff80-f076-0000-0000-0000-0000-0000-0010

func GetInterfaceByIP

func GetInterfaceByIP(ip net.IP) string

GetInterfaceByIP returns the name of interface containing provided ip.

func GetSubnet

func GetSubnet(ifaceName string) *net.IPNet

GetSubnet returns pointer to net.IPNet for the specified interface or nil if the search fails.

func IfaceHasStaticIP

func IfaceHasStaticIP(ifaceName string) (has bool, err error)

IfaceHasStaticIP checks if interface is configured to have static IP address. If it can't give a definitive answer, it returns false and an error for which errors.Is(err, ErrNoStaticIPInfo) is true.

func IfaceSetStaticIP

func IfaceSetStaticIP(ifaceName string) (err error)

IfaceSetStaticIP sets static IP address for network interface.

func IsValidHostOuterRune

func IsValidHostOuterRune(r rune) (ok bool)

IsValidHostOuterRune returns true if r is a valid initial or final rune for a hostname label.

func ReverseAddr

func ReverseAddr(ip net.IP) (arpa string)

ReverseAddr returns the ARPA hostname of the ip suitable for reverse DNS (PTR) record lookups. This is the modified version of ReverseAddr from github.com/miekg/dns package with no error among returned values.

func SplitHost

func SplitHost(hostport string) (host string, err error)

SplitHost is a wrapper for net.SplitHostPort for the cases when the hostport does not necessarily contain a port.

func UnreverseAddr

func UnreverseAddr(arpa string) (unreversed net.IP)

UnreverseAddr tries to convert reversed ARPA to a normal IP address.

func ValidateDomainName

func ValidateDomainName(name string) (err error)

ValidateDomainName validates the domain name in accordance to RFC 952, RFC 1035, and with RFC-1123's inclusion of digits at the start of the host. It doesn't validate against two or more hyphens to allow punycode and internationalized domains.

TODO(a.garipov): After making sure that this works correctly, port this into module golibs.

func ValidateDomainNameLabel

func ValidateDomainNameLabel(label string) (err error)

ValidateDomainNameLabel returns an error if label is not a valid label of a domain name.

func ValidateHardwareAddress

func ValidateHardwareAddress(hwa net.HardwareAddr) (err error)

ValidateHardwareAddress returns an error if hwa is not a valid EUI-48, EUI-64, or 20-octet InfiniBand link-layer address.

Types

type EtcHostsContainer

type EtcHostsContainer struct {
	// contains filtered or unexported fields
}

EtcHostsContainer - automatic DNS records

TODO(e.burkov): Move the logic under interface. Refactor. Probably remove the resolving logic.

func (*EtcHostsContainer) Close

func (ehc *EtcHostsContainer) Close()

Close - close module

func (*EtcHostsContainer) Init

func (ehc *EtcHostsContainer) Init(hostsFn string)

Init - initialize hostsFn: Override default name for the hosts-file (optional)

func (*EtcHostsContainer) List

func (ehc *EtcHostsContainer) List() (ipToHosts map[string][]string)

List returns an IP-to-hostnames table. It is safe for concurrent use.

func (*EtcHostsContainer) Process

func (ehc *EtcHostsContainer) Process(host string, qtype uint16) []net.IP

Process returns the list of IP addresses for the hostname or nil if nothing found.

func (*EtcHostsContainer) ProcessReverse

func (ehc *EtcHostsContainer) ProcessReverse(addr string, qtype uint16) (hosts []string)

ProcessReverse processes a PTR request. It returns nil if nothing is found.

func (*EtcHostsContainer) SetOnChanged

func (ehc *EtcHostsContainer) SetOnChanged(onChanged onChangedT)

SetOnChanged - set callback function that will be called when the data is changed

func (*EtcHostsContainer) Start

func (ehc *EtcHostsContainer) Start()

Start - start module

type HostGenFunc

type HostGenFunc func() (host string)

HostGenFunc is the signature for functions generating fake hostnames. The implementation must be safe for concurrent use.

type NetInterface

type NetInterface struct {
	MTU          int              `json:"mtu"`
	Name         string           `json:"name"`
	HardwareAddr net.HardwareAddr `json:"hardware_address"`
	Flags        net.Flags        `json:"flags"`
	// Array with the network interface addresses.
	Addresses []net.IP `json:"ip_addresses,omitempty"`
	// Array with IP networks for this network interface.
	Subnets []*net.IPNet `json:"-"`
}

NetInterface represents an entry of network interfaces map.

func GetValidNetInterfacesForWeb

func GetValidNetInterfacesForWeb() ([]*NetInterface, error)

GetValidNetInterfacesForWeb returns interfaces that are eligible for DNS and WEB only we do not return link-local addresses here

func (*NetInterface) MarshalJSON

func (iface *NetInterface) MarshalJSON() ([]byte, error)

MarshalJSON implements the json.Marshaler interface for *NetInterface.

type SubnetDetector

type SubnetDetector struct {
	// contains filtered or unexported fields
}

SubnetDetector describes IP address properties.

func NewSubnetDetector

func NewSubnetDetector() (snd *SubnetDetector, err error)

NewSubnetDetector returns a new IP detector.

func (*SubnetDetector) IsLocallyServedNetwork

func (snd *SubnetDetector) IsLocallyServedNetwork(ip net.IP) (is bool)

IsLocallyServedNetwork returns true if IP address is contained by any of locally-served IP address registries. It's safe for concurrent use.

func (*SubnetDetector) IsSpecialNetwork

func (snd *SubnetDetector) IsSpecialNetwork(ip net.IP) (is bool)

IsSpecialNetwork returns true if IP address is contained by any of special-purpose IP address registries. It's safe for concurrent use.

type SystemResolvers

type SystemResolvers interface {
	// Get returns the slice of local resolvers' addresses.
	// It should be safe for concurrent use.
	Get() (rs []string)
	// contains filtered or unexported methods
}

SystemResolvers helps to work with local resolvers' addresses provided by OS.

func NewSystemResolvers

func NewSystemResolvers(
	refreshIvl time.Duration,
	hostGenFunc HostGenFunc,
) (sr SystemResolvers, err error)

NewSystemResolvers returns a SystemResolvers with the cache refresh rate defined by refreshIvl. It disables auto-resfreshing if refreshIvl is 0. If nil is passed for hostGenFunc, the default generator will be used.