Documentation ¶
Overview ¶
Package net provides a portable interface for network I/O, including TCP/IP, UDP, domain name resolution, and Unix domain sockets.
Although the package provides access to low-level networking primitives, most clients will need only the basic interface provided by the Dial, Listen, and Accept functions and the associated Conn and Listener interfaces. The crypto/tls package uses the same interfaces and similar Dial and Listen functions.
The Dial function connects to a server:
conn, err := net.Dial("tcp", "google.com:80") if err != nil { // handle error } fmt.Fprintf(conn, "GET / HTTP/1.0\r\n\r\n") status, err := bufio.NewReader(conn).ReadString('\n') // ...
The Listen function creates servers:
ln, err := net.Listen("tcp", ":8080") if err != nil { // handle error } for { conn, err := ln.Accept() if err != nil { // handle error } go handleConnection(conn) }
Index ¶
- Constants
- Variables
- func JoinHostPort(host, port string) string
- func LookupAddr(addr string) (names []string, err error)
- func LookupCNAME(name string) (cname string, err error)
- func LookupHost(host string) (addrs []string, err error)
- func LookupPort(network, service string) (port int, err error)
- func LookupTXT(name string) (txts []string, err error)
- func ParseCIDR(s string) (IP, *IPNet, error)
- func Pipe() (Conn, Conn)
- func SplitHostPort(hostport string) (host, port string, err error)
- type Addr
- type AddrError
- type Conn
- type DNSConfigError
- type DNSError
- type Dialer
- type Error
- type Flags
- type HardwareAddr
- type IP
- func (ip IP) DefaultMask() IPMask
- func (ip IP) Equal(x IP) bool
- func (ip IP) IsGlobalUnicast() bool
- func (ip IP) IsInterfaceLocalMulticast() bool
- func (ip IP) IsLinkLocalMulticast() bool
- func (ip IP) IsLinkLocalUnicast() bool
- func (ip IP) IsLoopback() bool
- func (ip IP) IsMulticast() bool
- func (ip IP) IsUnspecified() bool
- func (ip IP) MarshalText() ([]byte, error)
- func (ip IP) Mask(mask IPMask) IP
- func (ip IP) String() string
- func (ip IP) To16() IP
- func (ip IP) To4() IP
- func (ip *IP) UnmarshalText(text []byte) error
- type IPAddr
- type IPConn
- func (c *IPConn) Close() error
- func (c *IPConn) File() (f *os.File, err error)
- func (c *IPConn) LocalAddr() Addr
- func (c *IPConn) Read(b []byte) (int, error)
- func (c *IPConn) ReadFrom(b []byte) (int, Addr, error)
- func (c *IPConn) ReadFromIP(b []byte) (int, *IPAddr, error)
- func (c *IPConn) ReadMsgIP(b, oob []byte) (n, oobn, flags int, addr *IPAddr, err error)
- func (c *IPConn) RemoteAddr() Addr
- func (c *IPConn) SetDeadline(t time.Time) error
- func (c *IPConn) SetReadBuffer(bytes int) error
- func (c *IPConn) SetReadDeadline(t time.Time) error
- func (c *IPConn) SetWriteBuffer(bytes int) error
- func (c *IPConn) SetWriteDeadline(t time.Time) error
- func (c *IPConn) Write(b []byte) (int, error)
- func (c *IPConn) WriteMsgIP(b, oob []byte, addr *IPAddr) (n, oobn int, err error)
- func (c *IPConn) WriteTo(b []byte, addr Addr) (int, error)
- func (c *IPConn) WriteToIP(b []byte, addr *IPAddr) (int, error)
- type IPMask
- type IPNet
- type Interface
- type InvalidAddrError
- type Listener
- type MX
- type NS
- type OpError
- type PacketConn
- type ParseError
- type SRV
- type TCPAddr
- type TCPConn
- func (c *TCPConn) Close() error
- func (c *TCPConn) CloseRead() error
- func (c *TCPConn) CloseWrite() error
- func (c *TCPConn) File() (f *os.File, err error)
- func (c *TCPConn) LocalAddr() Addr
- func (c *TCPConn) Read(b []byte) (int, error)
- func (c *TCPConn) ReadFrom(r io.Reader) (int64, error)
- func (c *TCPConn) RemoteAddr() Addr
- func (c *TCPConn) SetDeadline(t time.Time) error
- func (c *TCPConn) SetKeepAlive(keepalive bool) error
- func (c *TCPConn) SetKeepAlivePeriod(d time.Duration) error
- func (c *TCPConn) SetLinger(sec int) error
- func (c *TCPConn) SetNoDelay(noDelay bool) error
- func (c *TCPConn) SetReadBuffer(bytes int) error
- func (c *TCPConn) SetReadDeadline(t time.Time) error
- func (c *TCPConn) SetWriteBuffer(bytes int) error
- func (c *TCPConn) SetWriteDeadline(t time.Time) error
- func (c *TCPConn) Write(b []byte) (int, error)
- type TCPListener
- type UDPAddr
- type UDPConn
- func (c *UDPConn) Close() error
- func (c *UDPConn) File() (f *os.File, err error)
- func (c *UDPConn) LocalAddr() Addr
- func (c *UDPConn) Read(b []byte) (int, error)
- func (c *UDPConn) ReadFrom(b []byte) (int, Addr, error)
- func (c *UDPConn) ReadFromUDP(b []byte) (int, *UDPAddr, error)
- func (c *UDPConn) ReadMsgUDP(b, oob []byte) (n, oobn, flags int, addr *UDPAddr, err error)
- func (c *UDPConn) RemoteAddr() Addr
- func (c *UDPConn) SetDeadline(t time.Time) error
- func (c *UDPConn) SetReadBuffer(bytes int) error
- func (c *UDPConn) SetReadDeadline(t time.Time) error
- func (c *UDPConn) SetWriteBuffer(bytes int) error
- func (c *UDPConn) SetWriteDeadline(t time.Time) error
- func (c *UDPConn) Write(b []byte) (int, error)
- func (c *UDPConn) WriteMsgUDP(b, oob []byte, addr *UDPAddr) (n, oobn int, err error)
- func (c *UDPConn) WriteTo(b []byte, addr Addr) (int, error)
- func (c *UDPConn) WriteToUDP(b []byte, addr *UDPAddr) (int, error)
- type UnixAddr
- type UnixConn
- func (c *UnixConn) Close() error
- func (c *UnixConn) CloseRead() error
- func (c *UnixConn) CloseWrite() error
- func (c *UnixConn) File() (f *os.File, err error)
- func (c *UnixConn) LocalAddr() Addr
- func (c *UnixConn) Read(b []byte) (int, error)
- func (c *UnixConn) ReadFrom(b []byte) (int, Addr, error)
- func (c *UnixConn) ReadFromUnix(b []byte) (int, *UnixAddr, error)
- func (c *UnixConn) ReadMsgUnix(b, oob []byte) (n, oobn, flags int, addr *UnixAddr, err error)
- func (c *UnixConn) RemoteAddr() Addr
- func (c *UnixConn) SetDeadline(t time.Time) error
- func (c *UnixConn) SetReadBuffer(bytes int) error
- func (c *UnixConn) SetReadDeadline(t time.Time) error
- func (c *UnixConn) SetWriteBuffer(bytes int) error
- func (c *UnixConn) SetWriteDeadline(t time.Time) error
- func (c *UnixConn) Write(b []byte) (int, error)
- func (c *UnixConn) WriteMsgUnix(b, oob []byte, addr *UnixAddr) (n, oobn int, err error)
- func (c *UnixConn) WriteTo(b []byte, addr Addr) (n int, err error)
- func (c *UnixConn) WriteToUnix(b []byte, addr *UnixAddr) (int, error)
- type UnixListener
- type UnknownNetworkError
- Bugs
Examples ¶
Constants ¶
const ( IPv4len = 4 IPv6len = 16 )
IP address lengths (bytes).
Variables ¶
var ( IPv4bcast = IPv4(255, 255, 255, 255) // broadcast IPv4allsys = IPv4(224, 0, 0, 1) // all systems IPv4allrouter = IPv4(224, 0, 0, 2) // all routers IPv4zero = IPv4(0, 0, 0, 0) // all zeros )
Well-known IPv4 addresses
var ( IPv6zero = IP{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} IPv6unspecified = IP{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} IPv6loopback = IP{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1} IPv6interfacelocalallnodes = IP{0xff, 0x01, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x01} IPv6linklocalallnodes = IP{0xff, 0x02, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x01} IPv6linklocalallrouters = IP{0xff, 0x02, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x02} )
Well-known IPv6 addresses
var (
ErrWriteToConnected = errors.New("use of WriteTo with pre-connected connection")
)
Various errors contained in OpError.
Functions ¶
func JoinHostPort ¶
JoinHostPort combines host and port into a network address of the form "host:port" or, if host contains a colon or a percent sign, "[host]:port".
func LookupAddr ¶
LookupAddr performs a reverse lookup for the given address, returning a list of names mapping to that address.
func LookupCNAME ¶
LookupCNAME returns the canonical DNS host for the given name. Callers that do not care about the canonical name can call LookupHost or LookupIP directly; both take care of resolving the canonical name as part of the lookup.
func LookupHost ¶
LookupHost looks up the given host using the local resolver. It returns an array of that host's addresses.
func LookupPort ¶
LookupPort looks up the port for the given network and service.
func ParseCIDR ¶
ParseCIDR parses s as a CIDR notation IP address and mask, like "192.168.100.1/24" or "2001:DB8::/48", as defined in RFC 4632 and RFC 4291.
It returns the IP address and the network implied by the IP and mask. For example, ParseCIDR("192.168.100.1/16") returns the IP address 192.168.100.1 and the network 192.168.0.0/16.
func Pipe ¶
Pipe creates a synchronous, in-memory, full duplex network connection; both ends implement the Conn interface. Reads on one end are matched with writes on the other, copying data directly between the two; there is no internal buffering.
func SplitHostPort ¶
SplitHostPort splits a network address of the form "host:port", "[host]:port" or "[ipv6-host%zone]:port" into host or ipv6-host%zone and port. A literal address or host name for IPv6 must be enclosed in square brackets, as in "[::1]:80", "[ipv6-host]:http" or "[ipv6-host%zone]:80".
Types ¶
type Addr ¶
type Addr interface { Network() string // name of the network String() string // string form of address }
Addr represents a network end point address.
func InterfaceAddrs ¶
InterfaceAddrs returns a list of the system's network interface addresses.
type Conn ¶
type Conn interface { // Read reads data from the connection. // Read can be made to time out and return a Error with Timeout() == true // after a fixed time limit; see SetDeadline and SetReadDeadline. Read(b []byte) (n int, err error) // Write writes data to the connection. // Write can be made to time out and return a Error with Timeout() == true // after a fixed time limit; see SetDeadline and SetWriteDeadline. Write(b []byte) (n int, err error) // Close closes the connection. // Any blocked Read or Write operations will be unblocked and return errors. Close() error // LocalAddr returns the local network address. LocalAddr() Addr // RemoteAddr returns the remote network address. RemoteAddr() Addr // SetDeadline sets the read and write deadlines associated // with the connection. It is equivalent to calling both // SetReadDeadline and SetWriteDeadline. // // A deadline is an absolute time after which I/O operations // fail with a timeout (see type Error) instead of // blocking. The deadline applies to all future I/O, not just // the immediately following call to Read or Write. // // An idle timeout can be implemented by repeatedly extending // the deadline after successful Read or Write calls. // // A zero value for t means I/O operations will not time out. SetDeadline(t time.Time) error // SetReadDeadline sets the deadline for future Read calls. // A zero value for t means Read will not time out. SetReadDeadline(t time.Time) error // SetWriteDeadline sets the deadline for future Write calls. // Even if write times out, it may return n > 0, indicating that // some of the data was successfully written. // A zero value for t means Write will not time out. SetWriteDeadline(t time.Time) error }
Conn is a generic stream-oriented network connection.
Multiple goroutines may invoke methods on a Conn simultaneously.
func Dial ¶
Dial connects to the address on the named network.
Known networks are "tcp", "tcp4" (IPv4-only), "tcp6" (IPv6-only), "udp", "udp4" (IPv4-only), "udp6" (IPv6-only), "ip", "ip4" (IPv4-only), "ip6" (IPv6-only), "unix", "unixgram" and "unixpacket".
For TCP and UDP networks, addresses have the form host:port. If host is a literal IPv6 address it must be enclosed in square brackets as in "[::1]:80" or "[ipv6-host%zone]:80". The functions JoinHostPort and SplitHostPort manipulate addresses in this form.
Examples:
Dial("tcp", "12.34.56.78:80") Dial("tcp", "google.com:http") Dial("tcp", "[2001:db8::1]:http") Dial("tcp", "[fe80::1%lo0]:80")
For IP networks, the network must be "ip", "ip4" or "ip6" followed by a colon and a protocol number or name and the addr must be a literal IP address.
Examples:
Dial("ip4:1", "127.0.0.1") Dial("ip6:ospf", "::1")
For Unix networks, the address must be a file system path.
func DialTimeout ¶
DialTimeout acts like Dial but takes a timeout. The timeout includes name resolution, if required.
type DNSConfigError ¶
type DNSConfigError struct {
Err error
}
DNSConfigError represents an error reading the machine's DNS configuration. (No longer used; kept for compatibility.)
func (*DNSConfigError) Error ¶
func (e *DNSConfigError) Error() string
func (*DNSConfigError) Temporary ¶
func (e *DNSConfigError) Temporary() bool
func (*DNSConfigError) Timeout ¶
func (e *DNSConfigError) Timeout() bool
type DNSError ¶
type DNSError struct { Err string // description of the error Name string // name looked for Server string // server used IsTimeout bool // if true, timed out; not all timeouts set this }
DNSError represents a DNS lookup error.
type Dialer ¶
type Dialer struct { // Timeout is the maximum amount of time a dial will wait for // a connect to complete. If Deadline is also set, it may fail // earlier. // // The default is no timeout. // // When dialing a name with multiple IP addresses, the timeout // may be divided between them. // // With or without a timeout, the operating system may impose // its own earlier timeout. For instance, TCP timeouts are // often around 3 minutes. Timeout time.Duration // Deadline is the absolute point in time after which dials // will fail. If Timeout is set, it may fail earlier. // Zero means no deadline, or dependent on the operating system // as with the Timeout option. Deadline time.Time // LocalAddr is the local address to use when dialing an // address. The address must be of a compatible type for the // network being dialed. // If nil, a local address is automatically chosen. LocalAddr Addr // DualStack enables RFC 6555-compliant "Happy Eyeballs" dialing // when the network is "tcp" and the destination is a host name // with both IPv4 and IPv6 addresses. This allows a client to // tolerate networks where one address family is silently broken. DualStack bool // FallbackDelay specifies the length of time to wait before // spawning a fallback connection, when DualStack is enabled. // If zero, a default delay of 300ms is used. FallbackDelay time.Duration // KeepAlive specifies the keep-alive period for an active // network connection. // If zero, keep-alives are not enabled. Network protocols // that do not support keep-alives ignore this field. KeepAlive time.Duration }
A Dialer contains options for connecting to an address.
The zero value for each field is equivalent to dialing without that option. Dialing with the zero value of Dialer is therefore equivalent to just calling the Dial function.
type Error ¶
type Error interface { error Timeout() bool // Is the error a timeout? Temporary() bool // Is the error temporary? }
An Error represents a network error.
type HardwareAddr ¶
type HardwareAddr []byte
A HardwareAddr represents a physical hardware address.
func ParseMAC ¶
func ParseMAC(s string) (hw HardwareAddr, err error)
ParseMAC parses s as an IEEE 802 MAC-48, EUI-48, or EUI-64 using one of the following formats:
01:23:45:67:89:ab 01:23:45:67:89:ab:cd:ef 01-23-45-67-89-ab 01-23-45-67-89-ab-cd-ef 0123.4567.89ab 0123.4567.89ab.cdef
func (HardwareAddr) String ¶
func (a HardwareAddr) String() string
type IP ¶
type IP []byte
An IP is a single IP address, a slice of bytes. Functions in this package accept either 4-byte (IPv4) or 16-byte (IPv6) slices as input.
Note that in this documentation, referring to an IP address as an IPv4 address or an IPv6 address is a semantic property of the address, not just the length of the byte slice: a 16-byte slice can still be an IPv4 address.
func LookupIP ¶
LookupIP looks up host using the local resolver. It returns an array of that host's IPv4 and IPv6 addresses.
func ParseIP ¶
ParseIP parses s as an IP address, returning the result. The string s can be in dotted decimal ("74.125.19.99") or IPv6 ("2001:4860:0:2001::68") form. If s is not a valid textual representation of an IP address, ParseIP returns nil.
func (IP) DefaultMask ¶
DefaultMask returns the default IP mask for the IP address ip. Only IPv4 addresses have default masks; DefaultMask returns nil if ip is not a valid IPv4 address.
func (IP) Equal ¶
Equal reports whether ip and x are the same IP address. An IPv4 address and that same address in IPv6 form are considered to be equal.
func (IP) IsGlobalUnicast ¶
IsGlobalUnicast reports whether ip is a global unicast address.
func (IP) IsInterfaceLocalMulticast ¶
IsInterfaceLocalMulticast reports whether ip is an interface-local multicast address.
func (IP) IsLinkLocalMulticast ¶
IsLinkLocalMulticast reports whether ip is a link-local multicast address.
func (IP) IsLinkLocalUnicast ¶
IsLinkLocalUnicast reports whether ip is a link-local unicast address.
func (IP) IsLoopback ¶
IsLoopback reports whether ip is a loopback address.
func (IP) IsMulticast ¶
IsMulticast reports whether ip is a multicast address.
func (IP) IsUnspecified ¶
IsUnspecified reports whether ip is an unspecified address.
func (IP) MarshalText ¶
MarshalText implements the encoding.TextMarshaler interface. The encoding is the same as returned by String.
func (IP) String ¶
String returns the string form of the IP address ip. If the address is an IPv4 address, the string representation is dotted decimal ("74.125.19.99"). Otherwise the representation is IPv6 ("2001:4860:0:2001::68").
func (IP) To16 ¶
To16 converts the IP address ip to a 16-byte representation. If ip is not an IP address (it is the wrong length), To16 returns nil.
func (IP) To4 ¶
To4 converts the IPv4 address ip to a 4-byte representation. If ip is not an IPv4 address, To4 returns nil.
func (*IP) UnmarshalText ¶
UnmarshalText implements the encoding.TextUnmarshaler interface. The IP address is expected in a form accepted by ParseIP.
type IPAddr ¶
IPAddr represents the address of an IP end point.
func ResolveIPAddr ¶
ResolveIPAddr parses addr as an IP address of the form "host" or "ipv6-host%zone" and resolves the domain name on the network net, which must be "ip", "ip4" or "ip6".
type IPConn ¶
type IPConn struct {
// contains filtered or unexported fields
}
IPConn is the implementation of the Conn and PacketConn interfaces for IP network connections.
func DialIP ¶
DialIP connects to the remote address raddr on the network protocol netProto, which must be "ip", "ip4", or "ip6" followed by a colon and a protocol number or name.
func ListenIP ¶
ListenIP listens for incoming IP packets addressed to the local address laddr. The returned connection's ReadFrom and WriteTo methods can be used to receive and send IP packets with per-packet addressing.
func (*IPConn) File ¶
File sets the underlying os.File to blocking mode and returns a copy. It is the caller's responsibility to close f when finished. Closing c does not affect f, and closing f does not affect c.
The returned os.File's file descriptor is different from the connection's. Attempting to change properties of the original using this duplicate may or may not have the desired effect.
func (*IPConn) LocalAddr ¶
func (c *IPConn) LocalAddr() Addr
LocalAddr returns the local network address. The Addr returned is shared by all invocations of LocalAddr, so do not modify it.
func (*IPConn) ReadFromIP ¶
ReadFromIP reads an IP packet from c, copying the payload into b. It returns the number of bytes copied into b and the return address that was on the packet.
ReadFromIP can be made to time out and return an error with Timeout() == true after a fixed time limit; see SetDeadline and SetReadDeadline.
func (*IPConn) ReadMsgIP ¶
ReadMsgIP reads a packet from c, copying the payload into b and the associated out-of-band data into oob. It returns the number of bytes copied into b, the number of bytes copied into oob, the flags that were set on the packet and the source address of the packet.
func (*IPConn) RemoteAddr ¶
func (c *IPConn) RemoteAddr() Addr
RemoteAddr returns the remote network address. The Addr returned is shared by all invocations of RemoteAddr, so do not modify it.
func (*IPConn) SetDeadline ¶
SetDeadline implements the Conn SetDeadline method.
func (*IPConn) SetReadBuffer ¶
SetReadBuffer sets the size of the operating system's receive buffer associated with the connection.
func (*IPConn) SetReadDeadline ¶
SetReadDeadline implements the Conn SetReadDeadline method.
func (*IPConn) SetWriteBuffer ¶
SetWriteBuffer sets the size of the operating system's transmit buffer associated with the connection.
func (*IPConn) SetWriteDeadline ¶
SetWriteDeadline implements the Conn SetWriteDeadline method.
func (*IPConn) WriteMsgIP ¶
WriteMsgIP writes a packet to addr via c, copying the payload from b and the associated out-of-band data from oob. It returns the number of payload and out-of-band bytes written.
type IPMask ¶
type IPMask []byte
An IP mask is an IP address.
func CIDRMask ¶
CIDRMask returns an IPMask consisting of `ones' 1 bits followed by 0s up to a total length of `bits' bits. For a mask of this form, CIDRMask is the inverse of IPMask.Size.
type IPNet ¶
An IPNet represents an IP network.
func (*IPNet) String ¶
String returns the CIDR notation of n like "192.168.100.1/24" or "2001:DB8::/48" as defined in RFC 4632 and RFC 4291. If the mask is not in the canonical form, it returns the string which consists of an IP address, followed by a slash character and a mask expressed as hexadecimal form with no punctuation like "192.168.100.1/c000ff00".
type Interface ¶
type Interface struct { Index int // positive integer that starts at one, zero is never used MTU int // maximum transmission unit Name string // e.g., "en0", "lo0", "eth0.100" HardwareAddr HardwareAddr // IEEE MAC-48, EUI-48 and EUI-64 form Flags Flags // e.g., FlagUp, FlagLoopback, FlagMulticast }
Interface represents a mapping between network interface name and index. It also represents network interface facility information.
func InterfaceByIndex ¶
InterfaceByIndex returns the interface specified by index.
func InterfaceByName ¶
InterfaceByName returns the interface specified by name.
func Interfaces ¶
Interfaces returns a list of the system's network interfaces.
func (*Interface) MulticastAddrs ¶
MulticastAddrs returns multicast, joined group addresses for a specific interface.
type InvalidAddrError ¶
type InvalidAddrError string
func (InvalidAddrError) Error ¶
func (e InvalidAddrError) Error() string
func (InvalidAddrError) Temporary ¶
func (e InvalidAddrError) Temporary() bool
func (InvalidAddrError) Timeout ¶
func (e InvalidAddrError) Timeout() bool
type Listener ¶
type Listener interface { // Accept waits for and returns the next connection to the listener. Accept() (c Conn, err error) // Close closes the listener. // Any blocked Accept operations will be unblocked and return errors. Close() error // Addr returns the listener's network address. Addr() Addr }
A Listener is a generic network listener for stream-oriented protocols.
Multiple goroutines may invoke methods on a Listener simultaneously.
Example ¶
package main import ( "io" "log" "net" ) func main() { // Listen on TCP port 2000 on all interfaces. l, err := net.Listen("tcp", ":2000") if err != nil { log.Fatal(err) } defer l.Close() for { // Wait for a connection. conn, err := l.Accept() if err != nil { log.Fatal(err) } // Handle the connection in a new goroutine. // The loop then returns to accepting, so that // multiple connections may be served concurrently. go func(c net.Conn) { // Echo all incoming data. io.Copy(c, c) // Shut down the connection. c.Close() }(conn) } }
Output:
func FileListener ¶
FileListener returns a copy of the network listener corresponding to the open file f. It is the caller's responsibility to close ln when finished. Closing ln does not affect f, and closing f does not affect ln.
type OpError ¶
type OpError struct { // Op is the operation which caused the error, such as // "read" or "write". Op string // Net is the network type on which this error occurred, // such as "tcp" or "udp6". Net string // For operations involving a remote network connection, like // Dial, Read, or Write, Source is the corresponding local // network address. Source Addr // Addr is the network address for which this error occurred. // For local operations, like Listen or SetDeadline, Addr is // the address of the local endpoint being manipulated. // For operations involving a remote network connection, like // Dial, Read, or Write, Addr is the remote address of that // connection. Addr Addr // Err is the error that occurred during the operation. Err error }
OpError is the error type usually returned by functions in the net package. It describes the operation, network type, and address of an error.
type PacketConn ¶
type PacketConn interface { // ReadFrom reads a packet from the connection, // copying the payload into b. It returns the number of // bytes copied into b and the return address that // was on the packet. // ReadFrom can be made to time out and return // an error with Timeout() == true after a fixed time limit; // see SetDeadline and SetReadDeadline. ReadFrom(b []byte) (n int, addr Addr, err error) // WriteTo writes a packet with payload b to addr. // WriteTo can be made to time out and return // an error with Timeout() == true after a fixed time limit; // see SetDeadline and SetWriteDeadline. // On packet-oriented connections, write timeouts are rare. WriteTo(b []byte, addr Addr) (n int, err error) // Close closes the connection. // Any blocked ReadFrom or WriteTo operations will be unblocked and return errors. Close() error // LocalAddr returns the local network address. LocalAddr() Addr // SetDeadline sets the read and write deadlines associated // with the connection. SetDeadline(t time.Time) error // SetReadDeadline sets the deadline for future Read calls. // If the deadline is reached, Read will fail with a timeout // (see type Error) instead of blocking. // A zero value for t means Read will not time out. SetReadDeadline(t time.Time) error // SetWriteDeadline sets the deadline for future Write calls. // If the deadline is reached, Write will fail with a timeout // (see type Error) instead of blocking. // A zero value for t means Write will not time out. // Even if write times out, it may return n > 0, indicating that // some of the data was successfully written. SetWriteDeadline(t time.Time) error }
PacketConn is a generic packet-oriented network connection.
Multiple goroutines may invoke methods on a PacketConn simultaneously.
func FilePacketConn ¶
func FilePacketConn(f *os.File) (c PacketConn, err error)
FilePacketConn returns a copy of the packet network connection corresponding to the open file f. It is the caller's responsibility to close f when finished. Closing c does not affect f, and closing f does not affect c.
func ListenPacket ¶
func ListenPacket(net, laddr string) (PacketConn, error)
ListenPacket announces on the local network address laddr. The network net must be a packet-oriented network: "udp", "udp4", "udp6", "ip", "ip4", "ip6" or "unixgram". See Dial for the syntax of laddr.
type ParseError ¶
type ParseError struct { // Type is the type of string that was expected, such as // "IP address", "CIDR address". Type string // Text is the malformed text string. Text string }
A ParseError is the error type of literal network address parsers.
func (*ParseError) Error ¶
func (e *ParseError) Error() string
type SRV ¶
An SRV represents a single DNS SRV record.
func LookupSRV ¶
LookupSRV tries to resolve an SRV query of the given service, protocol, and domain name. The proto is "tcp" or "udp". The returned records are sorted by priority and randomized by weight within a priority.
LookupSRV constructs the DNS name to look up following RFC 2782. That is, it looks up _service._proto.name. To accommodate services publishing SRV records under non-standard names, if both service and proto are empty strings, LookupSRV looks up name directly.
type TCPAddr ¶
TCPAddr represents the address of a TCP end point.
func ResolveTCPAddr ¶
ResolveTCPAddr parses addr as a TCP address of the form "host:port" or "[ipv6-host%zone]:port" and resolves a pair of domain name and port name on the network net, which must be "tcp", "tcp4" or "tcp6". A literal address or host name for IPv6 must be enclosed in square brackets, as in "[::1]:80", "[ipv6-host]:http" or "[ipv6-host%zone]:80".
type TCPConn ¶
type TCPConn struct {
// contains filtered or unexported fields
}
TCPConn is an implementation of the Conn interface for TCP network connections.
func DialTCP ¶
DialTCP connects to the remote address raddr on the network net, which must be "tcp", "tcp4", or "tcp6". If laddr is not nil, it is used as the local address for the connection.
func (*TCPConn) CloseRead ¶
CloseRead shuts down the reading side of the TCP connection. Most callers should just use Close.
func (*TCPConn) CloseWrite ¶
CloseWrite shuts down the writing side of the TCP connection. Most callers should just use Close.
func (*TCPConn) File ¶
File sets the underlying os.File to blocking mode and returns a copy. It is the caller's responsibility to close f when finished. Closing c does not affect f, and closing f does not affect c.
The returned os.File's file descriptor is different from the connection's. Attempting to change properties of the original using this duplicate may or may not have the desired effect.
func (*TCPConn) LocalAddr ¶
func (c *TCPConn) LocalAddr() Addr
LocalAddr returns the local network address. The Addr returned is shared by all invocations of LocalAddr, so do not modify it.
func (*TCPConn) RemoteAddr ¶
func (c *TCPConn) RemoteAddr() Addr
RemoteAddr returns the remote network address. The Addr returned is shared by all invocations of RemoteAddr, so do not modify it.
func (*TCPConn) SetDeadline ¶
SetDeadline implements the Conn SetDeadline method.
func (*TCPConn) SetKeepAlive ¶
SetKeepAlive sets whether the operating system should send keepalive messages on the connection.
func (*TCPConn) SetKeepAlivePeriod ¶
SetKeepAlivePeriod sets period between keep alives.
func (*TCPConn) SetLinger ¶
SetLinger sets the behavior of Close on a connection which still has data waiting to be sent or to be acknowledged.
If sec < 0 (the default), the operating system finishes sending the data in the background.
If sec == 0, the operating system discards any unsent or unacknowledged data.
If sec > 0, the data is sent in the background as with sec < 0. On some operating systems after sec seconds have elapsed any remaining unsent data may be discarded.
func (*TCPConn) SetNoDelay ¶
SetNoDelay controls whether the operating system should delay packet transmission in hopes of sending fewer packets (Nagle's algorithm). The default is true (no delay), meaning that data is sent as soon as possible after a Write.
func (*TCPConn) SetReadBuffer ¶
SetReadBuffer sets the size of the operating system's receive buffer associated with the connection.
func (*TCPConn) SetReadDeadline ¶
SetReadDeadline implements the Conn SetReadDeadline method.
func (*TCPConn) SetWriteBuffer ¶
SetWriteBuffer sets the size of the operating system's transmit buffer associated with the connection.
func (*TCPConn) SetWriteDeadline ¶
SetWriteDeadline implements the Conn SetWriteDeadline method.
type TCPListener ¶
type TCPListener struct {
// contains filtered or unexported fields
}
TCPListener is a TCP network listener. Clients should typically use variables of type Listener instead of assuming TCP.
func ListenTCP ¶
func ListenTCP(net string, laddr *TCPAddr) (*TCPListener, error)
ListenTCP announces on the TCP address laddr and returns a TCP listener. Net must be "tcp", "tcp4", or "tcp6". If laddr has a port of 0, ListenTCP will choose an available port. The caller can use the Addr method of TCPListener to retrieve the chosen address.
func (*TCPListener) Accept ¶
func (l *TCPListener) Accept() (Conn, error)
Accept implements the Accept method in the Listener interface; it waits for the next call and returns a generic Conn.
func (*TCPListener) AcceptTCP ¶
func (l *TCPListener) AcceptTCP() (*TCPConn, error)
AcceptTCP accepts the next incoming call and returns the new connection.
func (*TCPListener) Addr ¶
func (l *TCPListener) Addr() Addr
Addr returns the listener's network address, a *TCPAddr. The Addr returned is shared by all invocations of Addr, so do not modify it.
func (*TCPListener) Close ¶
func (l *TCPListener) Close() error
Close stops listening on the TCP address. Already Accepted connections are not closed.
func (*TCPListener) File ¶
func (l *TCPListener) File() (f *os.File, err error)
File returns a copy of the underlying os.File, set to blocking mode. It is the caller's responsibility to close f when finished. Closing l does not affect f, and closing f does not affect l.
The returned os.File's file descriptor is different from the connection's. Attempting to change properties of the original using this duplicate may or may not have the desired effect.
func (*TCPListener) SetDeadline ¶
func (l *TCPListener) SetDeadline(t time.Time) error
SetDeadline sets the deadline associated with the listener. A zero time value disables the deadline.
type UDPAddr ¶
UDPAddr represents the address of a UDP end point.
func ResolveUDPAddr ¶
ResolveUDPAddr parses addr as a UDP address of the form "host:port" or "[ipv6-host%zone]:port" and resolves a pair of domain name and port name on the network net, which must be "udp", "udp4" or "udp6". A literal address or host name for IPv6 must be enclosed in square brackets, as in "[::1]:80", "[ipv6-host]:http" or "[ipv6-host%zone]:80".
type UDPConn ¶
type UDPConn struct {
// contains filtered or unexported fields
}
UDPConn is the implementation of the Conn and PacketConn interfaces for UDP network connections.
func DialUDP ¶
DialUDP connects to the remote address raddr on the network net, which must be "udp", "udp4", or "udp6". If laddr is not nil, it is used as the local address for the connection.
func ListenMulticastUDP ¶
ListenMulticastUDP listens for incoming multicast UDP packets addressed to the group address gaddr on the interface ifi. Network must be "udp", "udp4" or "udp6". ListenMulticastUDP uses the system-assigned multicast interface when ifi is nil, although this is not recommended because the assignment depends on platforms and sometimes it might require routing configuration.
ListenMulticastUDP is just for convenience of simple, small applications. There are golang.org/x/net/ipv4 and golang.org/x/net/ipv6 packages for general purpose uses.
func ListenUDP ¶
ListenUDP listens for incoming UDP packets addressed to the local address laddr. Net must be "udp", "udp4", or "udp6". If laddr has a port of 0, ListenUDP will choose an available port. The LocalAddr method of the returned UDPConn can be used to discover the port. The returned connection's ReadFrom and WriteTo methods can be used to receive and send UDP packets with per-packet addressing.
func (*UDPConn) File ¶
File sets the underlying os.File to blocking mode and returns a copy. It is the caller's responsibility to close f when finished. Closing c does not affect f, and closing f does not affect c.
The returned os.File's file descriptor is different from the connection's. Attempting to change properties of the original using this duplicate may or may not have the desired effect.
func (*UDPConn) LocalAddr ¶
func (c *UDPConn) LocalAddr() Addr
LocalAddr returns the local network address. The Addr returned is shared by all invocations of LocalAddr, so do not modify it.
func (*UDPConn) ReadFromUDP ¶
ReadFromUDP reads a UDP packet from c, copying the payload into b. It returns the number of bytes copied into b and the return address that was on the packet.
ReadFromUDP can be made to time out and return an error with Timeout() == true after a fixed time limit; see SetDeadline and SetReadDeadline.
func (*UDPConn) ReadMsgUDP ¶
ReadMsgUDP reads a packet from c, copying the payload into b and the associated out-of-band data into oob. It returns the number of bytes copied into b, the number of bytes copied into oob, the flags that were set on the packet and the source address of the packet.
func (*UDPConn) RemoteAddr ¶
func (c *UDPConn) RemoteAddr() Addr
RemoteAddr returns the remote network address. The Addr returned is shared by all invocations of RemoteAddr, so do not modify it.
func (*UDPConn) SetDeadline ¶
SetDeadline implements the Conn SetDeadline method.
func (*UDPConn) SetReadBuffer ¶
SetReadBuffer sets the size of the operating system's receive buffer associated with the connection.
func (*UDPConn) SetReadDeadline ¶
SetReadDeadline implements the Conn SetReadDeadline method.
func (*UDPConn) SetWriteBuffer ¶
SetWriteBuffer sets the size of the operating system's transmit buffer associated with the connection.
func (*UDPConn) SetWriteDeadline ¶
SetWriteDeadline implements the Conn SetWriteDeadline method.
func (*UDPConn) WriteMsgUDP ¶
WriteMsgUDP writes a packet to addr via c if c isn't connected, or to c's remote destination address if c is connected (in which case addr must be nil). The payload is copied from b and the associated out-of-band data is copied from oob. It returns the number of payload and out-of-band bytes written.
func (*UDPConn) WriteToUDP ¶
WriteToUDP writes a UDP packet to addr via c, copying the payload from b.
WriteToUDP can be made to time out and return an error with Timeout() == true after a fixed time limit; see SetDeadline and SetWriteDeadline. On packet-oriented connections, write timeouts are rare.
type UnixAddr ¶
UnixAddr represents the address of a Unix domain socket end point.
func ResolveUnixAddr ¶
ResolveUnixAddr parses addr as a Unix domain socket address. The string net gives the network name, "unix", "unixgram" or "unixpacket".
type UnixConn ¶
type UnixConn struct {
// contains filtered or unexported fields
}
UnixConn is an implementation of the Conn interface for connections to Unix domain sockets.
func DialUnix ¶
DialUnix connects to the remote address raddr on the network net, which must be "unix", "unixgram" or "unixpacket". If laddr is not nil, it is used as the local address for the connection.
func ListenUnixgram ¶
ListenUnixgram listens for incoming Unix datagram packets addressed to the local address laddr. The network net must be "unixgram". The returned connection's ReadFrom and WriteTo methods can be used to receive and send packets with per-packet addressing.
func (*UnixConn) CloseRead ¶
CloseRead shuts down the reading side of the Unix domain connection. Most callers should just use Close.
func (*UnixConn) CloseWrite ¶
CloseWrite shuts down the writing side of the Unix domain connection. Most callers should just use Close.
func (*UnixConn) File ¶
File sets the underlying os.File to blocking mode and returns a copy. It is the caller's responsibility to close f when finished. Closing c does not affect f, and closing f does not affect c.
The returned os.File's file descriptor is different from the connection's. Attempting to change properties of the original using this duplicate may or may not have the desired effect.
func (*UnixConn) LocalAddr ¶
func (c *UnixConn) LocalAddr() Addr
LocalAddr returns the local network address. The Addr returned is shared by all invocations of LocalAddr, so do not modify it.
func (*UnixConn) ReadFromUnix ¶
ReadFromUnix reads a packet from c, copying the payload into b. It returns the number of bytes copied into b and the source address of the packet.
ReadFromUnix can be made to time out and return an error with Timeout() == true after a fixed time limit; see SetDeadline and SetReadDeadline.
func (*UnixConn) ReadMsgUnix ¶
ReadMsgUnix reads a packet from c, copying the payload into b and the associated out-of-band data into oob. It returns the number of bytes copied into b, the number of bytes copied into oob, the flags that were set on the packet, and the source address of the packet.
func (*UnixConn) RemoteAddr ¶
func (c *UnixConn) RemoteAddr() Addr
RemoteAddr returns the remote network address. The Addr returned is shared by all invocations of RemoteAddr, so do not modify it.
func (*UnixConn) SetDeadline ¶
SetDeadline implements the Conn SetDeadline method.
func (*UnixConn) SetReadBuffer ¶
SetReadBuffer sets the size of the operating system's receive buffer associated with the connection.
func (*UnixConn) SetReadDeadline ¶
SetReadDeadline implements the Conn SetReadDeadline method.
func (*UnixConn) SetWriteBuffer ¶
SetWriteBuffer sets the size of the operating system's transmit buffer associated with the connection.
func (*UnixConn) SetWriteDeadline ¶
SetWriteDeadline implements the Conn SetWriteDeadline method.
func (*UnixConn) WriteMsgUnix ¶
WriteMsgUnix writes a packet to addr via c, copying the payload from b and the associated out-of-band data from oob. It returns the number of payload and out-of-band bytes written.
func (*UnixConn) WriteToUnix ¶
WriteToUnix writes a packet to addr via c, copying the payload from b.
WriteToUnix can be made to time out and return an error with Timeout() == true after a fixed time limit; see SetDeadline and SetWriteDeadline. On packet-oriented connections, write timeouts are rare.
type UnixListener ¶
type UnixListener struct {
// contains filtered or unexported fields
}
UnixListener is a Unix domain socket listener. Clients should typically use variables of type Listener instead of assuming Unix domain sockets.
func ListenUnix ¶
func ListenUnix(net string, laddr *UnixAddr) (*UnixListener, error)
ListenUnix announces on the Unix domain socket laddr and returns a Unix listener. The network net must be "unix" or "unixpacket".
func (*UnixListener) Accept ¶
func (l *UnixListener) Accept() (c Conn, err error)
Accept implements the Accept method in the Listener interface; it waits for the next call and returns a generic Conn.
func (*UnixListener) AcceptUnix ¶
func (l *UnixListener) AcceptUnix() (*UnixConn, error)
AcceptUnix accepts the next incoming call and returns the new connection.
func (*UnixListener) Addr ¶
func (l *UnixListener) Addr() Addr
Addr returns the listener's network address. The Addr returned is shared by all invocations of Addr, so do not modify it.
func (*UnixListener) Close ¶
func (l *UnixListener) Close() error
Close stops listening on the Unix address. Already accepted connections are not closed.
func (*UnixListener) File ¶
func (l *UnixListener) File() (f *os.File, err error)
File returns a copy of the underlying os.File, set to blocking mode. It is the caller's responsibility to close f when finished. Closing l does not affect f, and closing f does not affect l.
The returned os.File's file descriptor is different from the connection's. Attempting to change properties of the original using this duplicate may or may not have the desired effect.
func (*UnixListener) SetDeadline ¶
func (l *UnixListener) SetDeadline(t time.Time) error
SetDeadline sets the deadline associated with the listener. A zero time value disables the deadline.
type UnknownNetworkError ¶
type UnknownNetworkError string
func (UnknownNetworkError) Error ¶
func (e UnknownNetworkError) Error() string
func (UnknownNetworkError) Temporary ¶
func (e UnknownNetworkError) Temporary() bool
func (UnknownNetworkError) Timeout ¶
func (e UnknownNetworkError) Timeout() bool
Notes ¶
Bugs ¶
On every POSIX platform, reads from the "ip4" network using the ReadFrom or ReadFromIP method might not return a complete IPv4 packet, including its header, even if there is space available. This can occur even in cases where Read or ReadMsgIP could return a complete packet. For this reason, it is recommended that you do not uses these methods if it is important to receive a full packet.
The Go 1 compatibility guidelines make it impossible for us to change the behavior of these methods; use Read or ReadMsgIP instead.
On DragonFly BSD and OpenBSD, listening on the "tcp" and "udp" networks does not listen for both IPv4 and IPv6 connections. This is due to the fact that IPv4 traffic will not be routed to an IPv6 socket - two separate sockets are required if both address families are to be supported. See inet6(4) for details.
Source Files ¶
- addrselect.go
- cgo_linux.go
- cgo_resnew.go
- cgo_socknew.go
- cgo_unix.go
- conf.go
- dial.go
- dnsclient.go
- dnsclient_unix.go
- dnsconfig_unix.go
- dnsmsg.go
- fd_mutex.go
- fd_poll_runtime.go
- fd_posix.go
- fd_unix.go
- file.go
- file_unix.go
- hook.go
- hook_cloexec.go
- hook_unix.go
- hosts.go
- interface.go
- interface_linux.go
- ip.go
- iprawsock.go
- iprawsock_posix.go
- ipsock.go
- ipsock_posix.go
- lookup.go
- lookup_unix.go
- mac.go
- net.go
- nss.go
- parse.go
- pipe.go
- port.go
- port_unix.go
- sendfile_linux.go
- sock_cloexec.go
- sock_linux.go
- sock_posix.go
- sockopt_linux.go
- sockopt_posix.go
- sockoptip_linux.go
- sockoptip_posix.go
- tcpsock.go
- tcpsock_posix.go
- tcpsockopt_posix.go
- tcpsockopt_unix.go
- udpsock.go
- udpsock_posix.go
- unixsock.go
- unixsock_posix.go
Directories ¶
Path | Synopsis |
---|---|
Package http provides HTTP client and server implementations.
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Package http provides HTTP client and server implementations. |
cgi
Package cgi implements CGI (Common Gateway Interface) as specified in RFC 3875.
|
Package cgi implements CGI (Common Gateway Interface) as specified in RFC 3875. |
cookiejar
Package cookiejar implements an in-memory RFC 6265-compliant http.CookieJar.
|
Package cookiejar implements an in-memory RFC 6265-compliant http.CookieJar. |
fcgi
Package fcgi implements the FastCGI protocol.
|
Package fcgi implements the FastCGI protocol. |
httptest
Package httptest provides utilities for HTTP testing.
|
Package httptest provides utilities for HTTP testing. |
httputil
Package httputil provides HTTP utility functions, complementing the more common ones in the net/http package.
|
Package httputil provides HTTP utility functions, complementing the more common ones in the net/http package. |
internal
Package internal contains HTTP internals shared by net/http and net/http/httputil.
|
Package internal contains HTTP internals shared by net/http and net/http/httputil. |
pprof
Package pprof serves via its HTTP server runtime profiling data in the format expected by the pprof visualization tool.
|
Package pprof serves via its HTTP server runtime profiling data in the format expected by the pprof visualization tool. |
internal
|
|
socktest
Package socktest provides utilities for socket testing.
|
Package socktest provides utilities for socket testing. |
Package mail implements parsing of mail messages.
|
Package mail implements parsing of mail messages. |
Package rpc provides access to the exported methods of an object across a network or other I/O connection.
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Package rpc provides access to the exported methods of an object across a network or other I/O connection. |
jsonrpc
Package jsonrpc implements a JSON-RPC ClientCodec and ServerCodec for the rpc package.
|
Package jsonrpc implements a JSON-RPC ClientCodec and ServerCodec for the rpc package. |
Package smtp implements the Simple Mail Transfer Protocol as defined in RFC 5321.
|
Package smtp implements the Simple Mail Transfer Protocol as defined in RFC 5321. |
Package textproto implements generic support for text-based request/response protocols in the style of HTTP, NNTP, and SMTP.
|
Package textproto implements generic support for text-based request/response protocols in the style of HTTP, NNTP, and SMTP. |
Package url parses URLs and implements query escaping.
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Package url parses URLs and implements query escaping. |