| // Copyright 2010 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. |
| |
| // +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris windows |
| |
| package net |
| |
| import ( |
| "syscall" |
| "time" |
| ) |
| |
| // BUG(mikio): 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. |
| |
| func sockaddrToIP(sa syscall.Sockaddr) Addr { |
| switch sa := sa.(type) { |
| case *syscall.SockaddrInet4: |
| return &IPAddr{IP: sa.Addr[0:]} |
| case *syscall.SockaddrInet6: |
| return &IPAddr{IP: sa.Addr[0:], Zone: zoneToString(int(sa.ZoneId))} |
| } |
| return nil |
| } |
| |
| func (a *IPAddr) family() int { |
| if a == nil || len(a.IP) <= IPv4len { |
| return syscall.AF_INET |
| } |
| if a.IP.To4() != nil { |
| return syscall.AF_INET |
| } |
| return syscall.AF_INET6 |
| } |
| |
| func (a *IPAddr) sockaddr(family int) (syscall.Sockaddr, error) { |
| if a == nil { |
| return nil, nil |
| } |
| return ipToSockaddr(family, a.IP, 0, a.Zone) |
| } |
| |
| // IPConn is the implementation of the Conn and PacketConn interfaces |
| // for IP network connections. |
| type IPConn struct { |
| conn |
| } |
| |
| func newIPConn(fd *netFD) *IPConn { return &IPConn{conn{fd}} } |
| |
| // 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 (c *IPConn) ReadFromIP(b []byte) (int, *IPAddr, error) { |
| if !c.ok() { |
| return 0, nil, syscall.EINVAL |
| } |
| // TODO(cw,rsc): consider using readv if we know the family |
| // type to avoid the header trim/copy |
| var addr *IPAddr |
| n, sa, err := c.fd.readFrom(b) |
| switch sa := sa.(type) { |
| case *syscall.SockaddrInet4: |
| addr = &IPAddr{IP: sa.Addr[0:]} |
| n = stripIPv4Header(n, b) |
| case *syscall.SockaddrInet6: |
| addr = &IPAddr{IP: sa.Addr[0:], Zone: zoneToString(int(sa.ZoneId))} |
| } |
| if err != nil { |
| err = &OpError{Op: "read", Net: c.fd.net, Addr: c.fd.laddr, Err: err} |
| } |
| return n, addr, err |
| } |
| |
| func stripIPv4Header(n int, b []byte) int { |
| if len(b) < 20 { |
| return n |
| } |
| l := int(b[0]&0x0f) << 2 |
| if 20 > l || l > len(b) { |
| return n |
| } |
| if b[0]>>4 != 4 { |
| return n |
| } |
| copy(b, b[l:]) |
| return n - l |
| } |
| |
| // ReadFrom implements the PacketConn ReadFrom method. |
| func (c *IPConn) ReadFrom(b []byte) (int, Addr, error) { |
| if !c.ok() { |
| return 0, nil, syscall.EINVAL |
| } |
| n, addr, err := c.ReadFromIP(b) |
| if addr == nil { |
| return n, nil, err |
| } |
| return n, addr, err |
| } |
| |
| // 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 (c *IPConn) ReadMsgIP(b, oob []byte) (n, oobn, flags int, addr *IPAddr, err error) { |
| if !c.ok() { |
| return 0, 0, 0, nil, syscall.EINVAL |
| } |
| var sa syscall.Sockaddr |
| n, oobn, flags, sa, err = c.fd.readMsg(b, oob) |
| switch sa := sa.(type) { |
| case *syscall.SockaddrInet4: |
| addr = &IPAddr{IP: sa.Addr[0:]} |
| case *syscall.SockaddrInet6: |
| addr = &IPAddr{IP: sa.Addr[0:], Zone: zoneToString(int(sa.ZoneId))} |
| } |
| if err != nil { |
| err = &OpError{Op: "read", Net: c.fd.net, Addr: c.fd.laddr, Err: err} |
| } |
| return |
| } |
| |
| // WriteToIP writes an IP packet to addr via c, copying the payload |
| // from b. |
| // |
| // WriteToIP 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. |
| func (c *IPConn) WriteToIP(b []byte, addr *IPAddr) (int, error) { |
| if !c.ok() { |
| return 0, syscall.EINVAL |
| } |
| if c.fd.isConnected { |
| return 0, &OpError{Op: "write", Net: c.fd.net, Addr: addr, Err: ErrWriteToConnected} |
| } |
| if addr == nil { |
| return 0, &OpError{Op: "write", Net: c.fd.net, Addr: nil, Err: errMissingAddress} |
| } |
| sa, err := addr.sockaddr(c.fd.family) |
| if err != nil { |
| return 0, &OpError{Op: "write", Net: c.fd.net, Addr: addr, Err: err} |
| } |
| n, err := c.fd.writeTo(b, sa) |
| if err != nil { |
| err = &OpError{Op: "write", Net: c.fd.net, Addr: addr, Err: err} |
| } |
| return n, err |
| } |
| |
| // WriteTo implements the PacketConn WriteTo method. |
| func (c *IPConn) WriteTo(b []byte, addr Addr) (int, error) { |
| if !c.ok() { |
| return 0, syscall.EINVAL |
| } |
| a, ok := addr.(*IPAddr) |
| if !ok { |
| return 0, &OpError{Op: "write", Net: c.fd.net, Addr: addr, Err: syscall.EINVAL} |
| } |
| return c.WriteToIP(b, a) |
| } |
| |
| // 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. |
| func (c *IPConn) WriteMsgIP(b, oob []byte, addr *IPAddr) (n, oobn int, err error) { |
| if !c.ok() { |
| return 0, 0, syscall.EINVAL |
| } |
| if c.fd.isConnected { |
| return 0, 0, &OpError{Op: "write", Net: c.fd.net, Addr: addr, Err: ErrWriteToConnected} |
| } |
| if addr == nil { |
| return 0, 0, &OpError{Op: "write", Net: c.fd.net, Addr: nil, Err: errMissingAddress} |
| } |
| var sa syscall.Sockaddr |
| sa, err = addr.sockaddr(c.fd.family) |
| if err != nil { |
| return 0, 0, &OpError{Op: "write", Net: c.fd.net, Addr: addr, Err: err} |
| } |
| n, oobn, err = c.fd.writeMsg(b, oob, sa) |
| if err != nil { |
| err = &OpError{Op: "write", Net: c.fd.net, Addr: addr, Err: err} |
| } |
| return |
| } |
| |
| // 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 DialIP(netProto string, laddr, raddr *IPAddr) (*IPConn, error) { |
| return dialIP(netProto, laddr, raddr, noDeadline) |
| } |
| |
| func dialIP(netProto string, laddr, raddr *IPAddr, deadline time.Time) (*IPConn, error) { |
| net, proto, err := parseNetwork(netProto) |
| if err != nil { |
| return nil, &OpError{Op: "dial", Net: netProto, Addr: raddr, Err: err} |
| } |
| switch net { |
| case "ip", "ip4", "ip6": |
| default: |
| return nil, &OpError{Op: "dial", Net: netProto, Addr: raddr, Err: UnknownNetworkError(netProto)} |
| } |
| if raddr == nil { |
| return nil, &OpError{Op: "dial", Net: netProto, Addr: nil, Err: errMissingAddress} |
| } |
| fd, err := internetSocket(net, laddr, raddr, deadline, syscall.SOCK_RAW, proto, "dial") |
| if err != nil { |
| return nil, &OpError{Op: "dial", Net: netProto, Addr: raddr, Err: err} |
| } |
| return newIPConn(fd), nil |
| } |
| |
| // 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 ListenIP(netProto string, laddr *IPAddr) (*IPConn, error) { |
| net, proto, err := parseNetwork(netProto) |
| if err != nil { |
| return nil, &OpError{Op: "dial", Net: netProto, Addr: laddr, Err: err} |
| } |
| switch net { |
| case "ip", "ip4", "ip6": |
| default: |
| return nil, &OpError{Op: "listen", Net: netProto, Addr: laddr, Err: UnknownNetworkError(netProto)} |
| } |
| fd, err := internetSocket(net, laddr, nil, noDeadline, syscall.SOCK_RAW, proto, "listen") |
| if err != nil { |
| return nil, &OpError{Op: "listen", Net: netProto, Addr: laddr, Err: err} |
| } |
| return newIPConn(fd), nil |
| } |