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Diffstat (limited to '')
-rw-r--r-- | src/net/tcpsock.go | 380 |
1 files changed, 380 insertions, 0 deletions
diff --git a/src/net/tcpsock.go b/src/net/tcpsock.go new file mode 100644 index 0000000..672170e --- /dev/null +++ b/src/net/tcpsock.go @@ -0,0 +1,380 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package net + +import ( + "context" + "internal/itoa" + "io" + "net/netip" + "os" + "syscall" + "time" +) + +// BUG(mikio): On JS and Windows, the File method of TCPConn and +// TCPListener is not implemented. + +// TCPAddr represents the address of a TCP end point. +type TCPAddr struct { + IP IP + Port int + Zone string // IPv6 scoped addressing zone +} + +// AddrPort returns the TCPAddr a as a netip.AddrPort. +// +// If a.Port does not fit in a uint16, it's silently truncated. +// +// If a is nil, a zero value is returned. +func (a *TCPAddr) AddrPort() netip.AddrPort { + if a == nil { + return netip.AddrPort{} + } + na, _ := netip.AddrFromSlice(a.IP) + na = na.WithZone(a.Zone) + return netip.AddrPortFrom(na, uint16(a.Port)) +} + +// Network returns the address's network name, "tcp". +func (a *TCPAddr) Network() string { return "tcp" } + +func (a *TCPAddr) String() string { + if a == nil { + return "<nil>" + } + ip := ipEmptyString(a.IP) + if a.Zone != "" { + return JoinHostPort(ip+"%"+a.Zone, itoa.Itoa(a.Port)) + } + return JoinHostPort(ip, itoa.Itoa(a.Port)) +} + +func (a *TCPAddr) isWildcard() bool { + if a == nil || a.IP == nil { + return true + } + return a.IP.IsUnspecified() +} + +func (a *TCPAddr) opAddr() Addr { + if a == nil { + return nil + } + return a +} + +// ResolveTCPAddr returns an address of TCP end point. +// +// The network must be a TCP network name. +// +// If the host in the address parameter is not a literal IP address or +// the port is not a literal port number, ResolveTCPAddr resolves the +// address to an address of TCP end point. +// Otherwise, it parses the address as a pair of literal IP address +// and port number. +// The address parameter can use a host name, but this is not +// recommended, because it will return at most one of the host name's +// IP addresses. +// +// See func Dial for a description of the network and address +// parameters. +func ResolveTCPAddr(network, address string) (*TCPAddr, error) { + switch network { + case "tcp", "tcp4", "tcp6": + case "": // a hint wildcard for Go 1.0 undocumented behavior + network = "tcp" + default: + return nil, UnknownNetworkError(network) + } + addrs, err := DefaultResolver.internetAddrList(context.Background(), network, address) + if err != nil { + return nil, err + } + return addrs.forResolve(network, address).(*TCPAddr), nil +} + +// TCPAddrFromAddrPort returns addr as a TCPAddr. If addr.IsValid() is false, +// then the returned TCPAddr will contain a nil IP field, indicating an +// address family-agnostic unspecified address. +func TCPAddrFromAddrPort(addr netip.AddrPort) *TCPAddr { + return &TCPAddr{ + IP: addr.Addr().AsSlice(), + Zone: addr.Addr().Zone(), + Port: int(addr.Port()), + } +} + +// TCPConn is an implementation of the Conn interface for TCP network +// connections. +type TCPConn struct { + conn +} + +// SyscallConn returns a raw network connection. +// This implements the syscall.Conn interface. +func (c *TCPConn) SyscallConn() (syscall.RawConn, error) { + if !c.ok() { + return nil, syscall.EINVAL + } + return newRawConn(c.fd) +} + +// ReadFrom implements the io.ReaderFrom ReadFrom method. +func (c *TCPConn) ReadFrom(r io.Reader) (int64, error) { + if !c.ok() { + return 0, syscall.EINVAL + } + n, err := c.readFrom(r) + if err != nil && err != io.EOF { + err = &OpError{Op: "readfrom", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err} + } + return n, err +} + +// CloseRead shuts down the reading side of the TCP connection. +// Most callers should just use Close. +func (c *TCPConn) CloseRead() error { + if !c.ok() { + return syscall.EINVAL + } + if err := c.fd.closeRead(); err != nil { + return &OpError{Op: "close", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err} + } + return nil +} + +// CloseWrite shuts down the writing side of the TCP connection. +// Most callers should just use Close. +func (c *TCPConn) CloseWrite() error { + if !c.ok() { + return syscall.EINVAL + } + if err := c.fd.closeWrite(); err != nil { + return &OpError{Op: "close", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err} + } + return nil +} + +// 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 (c *TCPConn) SetLinger(sec int) error { + if !c.ok() { + return syscall.EINVAL + } + if err := setLinger(c.fd, sec); err != nil { + return &OpError{Op: "set", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err} + } + return nil +} + +// SetKeepAlive sets whether the operating system should send +// keep-alive messages on the connection. +func (c *TCPConn) SetKeepAlive(keepalive bool) error { + if !c.ok() { + return syscall.EINVAL + } + if err := setKeepAlive(c.fd, keepalive); err != nil { + return &OpError{Op: "set", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err} + } + return nil +} + +// SetKeepAlivePeriod sets period between keep-alives. +func (c *TCPConn) SetKeepAlivePeriod(d time.Duration) error { + if !c.ok() { + return syscall.EINVAL + } + if err := setKeepAlivePeriod(c.fd, d); err != nil { + return &OpError{Op: "set", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err} + } + return nil +} + +// 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 (c *TCPConn) SetNoDelay(noDelay bool) error { + if !c.ok() { + return syscall.EINVAL + } + if err := setNoDelay(c.fd, noDelay); err != nil { + return &OpError{Op: "set", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err} + } + return nil +} + +func newTCPConn(fd *netFD, keepAlive time.Duration, keepAliveHook func(time.Duration)) *TCPConn { + setNoDelay(fd, true) + if keepAlive == 0 { + keepAlive = defaultTCPKeepAlive + } + if keepAlive > 0 { + setKeepAlive(fd, true) + setKeepAlivePeriod(fd, keepAlive) + if keepAliveHook != nil { + keepAliveHook(keepAlive) + } + } + return &TCPConn{conn{fd}} +} + +// DialTCP acts like Dial for TCP networks. +// +// The network must be a TCP network name; see func Dial for details. +// +// If laddr is nil, a local address is automatically chosen. +// If the IP field of raddr is nil or an unspecified IP address, the +// local system is assumed. +func DialTCP(network string, laddr, raddr *TCPAddr) (*TCPConn, error) { + switch network { + case "tcp", "tcp4", "tcp6": + default: + return nil, &OpError{Op: "dial", Net: network, Source: laddr.opAddr(), Addr: raddr.opAddr(), Err: UnknownNetworkError(network)} + } + if raddr == nil { + return nil, &OpError{Op: "dial", Net: network, Source: laddr.opAddr(), Addr: nil, Err: errMissingAddress} + } + sd := &sysDialer{network: network, address: raddr.String()} + c, err := sd.dialTCP(context.Background(), laddr, raddr) + if err != nil { + return nil, &OpError{Op: "dial", Net: network, Source: laddr.opAddr(), Addr: raddr.opAddr(), Err: err} + } + return c, nil +} + +// TCPListener is a TCP network listener. Clients should typically +// use variables of type Listener instead of assuming TCP. +type TCPListener struct { + fd *netFD + lc ListenConfig +} + +// SyscallConn returns a raw network connection. +// This implements the syscall.Conn interface. +// +// The returned RawConn only supports calling Control. Read and +// Write return an error. +func (l *TCPListener) SyscallConn() (syscall.RawConn, error) { + if !l.ok() { + return nil, syscall.EINVAL + } + return newRawListener(l.fd) +} + +// AcceptTCP accepts the next incoming call and returns the new +// connection. +func (l *TCPListener) AcceptTCP() (*TCPConn, error) { + if !l.ok() { + return nil, syscall.EINVAL + } + c, err := l.accept() + if err != nil { + return nil, &OpError{Op: "accept", Net: l.fd.net, Source: nil, Addr: l.fd.laddr, Err: err} + } + return c, nil +} + +// Accept implements the Accept method in the Listener interface; it +// waits for the next call and returns a generic Conn. +func (l *TCPListener) Accept() (Conn, error) { + if !l.ok() { + return nil, syscall.EINVAL + } + c, err := l.accept() + if err != nil { + return nil, &OpError{Op: "accept", Net: l.fd.net, Source: nil, Addr: l.fd.laddr, Err: err} + } + return c, nil +} + +// Close stops listening on the TCP address. +// Already Accepted connections are not closed. +func (l *TCPListener) Close() error { + if !l.ok() { + return syscall.EINVAL + } + if err := l.close(); err != nil { + return &OpError{Op: "close", Net: l.fd.net, Source: nil, Addr: l.fd.laddr, Err: err} + } + return nil +} + +// 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 (l *TCPListener) Addr() Addr { return l.fd.laddr } + +// SetDeadline sets the deadline associated with the listener. +// A zero time value disables the deadline. +func (l *TCPListener) SetDeadline(t time.Time) error { + if !l.ok() { + return syscall.EINVAL + } + if err := l.fd.pfd.SetDeadline(t); err != nil { + return &OpError{Op: "set", Net: l.fd.net, Source: nil, Addr: l.fd.laddr, Err: err} + } + return nil +} + +// File returns a copy of the underlying os.File. +// 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 (l *TCPListener) File() (f *os.File, err error) { + if !l.ok() { + return nil, syscall.EINVAL + } + f, err = l.file() + if err != nil { + return nil, &OpError{Op: "file", Net: l.fd.net, Source: nil, Addr: l.fd.laddr, Err: err} + } + return +} + +// ListenTCP acts like Listen for TCP networks. +// +// The network must be a TCP network name; see func Dial for details. +// +// If the IP field of laddr is nil or an unspecified IP address, +// ListenTCP listens on all available unicast and anycast IP addresses +// of the local system. +// If the Port field of laddr is 0, a port number is automatically +// chosen. +func ListenTCP(network string, laddr *TCPAddr) (*TCPListener, error) { + switch network { + case "tcp", "tcp4", "tcp6": + default: + return nil, &OpError{Op: "listen", Net: network, Source: nil, Addr: laddr.opAddr(), Err: UnknownNetworkError(network)} + } + if laddr == nil { + laddr = &TCPAddr{} + } + sl := &sysListener{network: network, address: laddr.String()} + ln, err := sl.listenTCP(context.Background(), laddr) + if err != nil { + return nil, &OpError{Op: "listen", Net: network, Source: nil, Addr: laddr.opAddr(), Err: err} + } + return ln, nil +} + +// roundDurationUp rounds d to the next multiple of to. +func roundDurationUp(d time.Duration, to time.Duration) time.Duration { + return (d + to - 1) / to +} |