github.com/gidoBOSSftw5731/go/src@v0.0.0-20210226122457-d24b0edbf019/net/iprawsock_posix.go (about) 1 // Copyright 2010 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 //go:build aix || darwin || dragonfly || freebsd || (js && wasm) || linux || netbsd || openbsd || solaris || windows 6 // +build aix darwin dragonfly freebsd js,wasm linux netbsd openbsd solaris windows 7 8 package net 9 10 import ( 11 "context" 12 "syscall" 13 ) 14 15 func sockaddrToIP(sa syscall.Sockaddr) Addr { 16 switch sa := sa.(type) { 17 case *syscall.SockaddrInet4: 18 return &IPAddr{IP: sa.Addr[0:]} 19 case *syscall.SockaddrInet6: 20 return &IPAddr{IP: sa.Addr[0:], Zone: zoneCache.name(int(sa.ZoneId))} 21 } 22 return nil 23 } 24 25 func (a *IPAddr) family() int { 26 if a == nil || len(a.IP) <= IPv4len { 27 return syscall.AF_INET 28 } 29 if a.IP.To4() != nil { 30 return syscall.AF_INET 31 } 32 return syscall.AF_INET6 33 } 34 35 func (a *IPAddr) sockaddr(family int) (syscall.Sockaddr, error) { 36 if a == nil { 37 return nil, nil 38 } 39 return ipToSockaddr(family, a.IP, 0, a.Zone) 40 } 41 42 func (a *IPAddr) toLocal(net string) sockaddr { 43 return &IPAddr{loopbackIP(net), a.Zone} 44 } 45 46 func (c *IPConn) readFrom(b []byte) (int, *IPAddr, error) { 47 // TODO(cw,rsc): consider using readv if we know the family 48 // type to avoid the header trim/copy 49 var addr *IPAddr 50 n, sa, err := c.fd.readFrom(b) 51 switch sa := sa.(type) { 52 case *syscall.SockaddrInet4: 53 addr = &IPAddr{IP: sa.Addr[0:]} 54 n = stripIPv4Header(n, b) 55 case *syscall.SockaddrInet6: 56 addr = &IPAddr{IP: sa.Addr[0:], Zone: zoneCache.name(int(sa.ZoneId))} 57 } 58 return n, addr, err 59 } 60 61 func stripIPv4Header(n int, b []byte) int { 62 if len(b) < 20 { 63 return n 64 } 65 l := int(b[0]&0x0f) << 2 66 if 20 > l || l > len(b) { 67 return n 68 } 69 if b[0]>>4 != 4 { 70 return n 71 } 72 copy(b, b[l:]) 73 return n - l 74 } 75 76 func (c *IPConn) readMsg(b, oob []byte) (n, oobn, flags int, addr *IPAddr, err error) { 77 var sa syscall.Sockaddr 78 n, oobn, flags, sa, err = c.fd.readMsg(b, oob) 79 switch sa := sa.(type) { 80 case *syscall.SockaddrInet4: 81 addr = &IPAddr{IP: sa.Addr[0:]} 82 case *syscall.SockaddrInet6: 83 addr = &IPAddr{IP: sa.Addr[0:], Zone: zoneCache.name(int(sa.ZoneId))} 84 } 85 return 86 } 87 88 func (c *IPConn) writeTo(b []byte, addr *IPAddr) (int, error) { 89 if c.fd.isConnected { 90 return 0, ErrWriteToConnected 91 } 92 if addr == nil { 93 return 0, errMissingAddress 94 } 95 sa, err := addr.sockaddr(c.fd.family) 96 if err != nil { 97 return 0, err 98 } 99 return c.fd.writeTo(b, sa) 100 } 101 102 func (c *IPConn) writeMsg(b, oob []byte, addr *IPAddr) (n, oobn int, err error) { 103 if c.fd.isConnected { 104 return 0, 0, ErrWriteToConnected 105 } 106 if addr == nil { 107 return 0, 0, errMissingAddress 108 } 109 sa, err := addr.sockaddr(c.fd.family) 110 if err != nil { 111 return 0, 0, err 112 } 113 return c.fd.writeMsg(b, oob, sa) 114 } 115 116 func (sd *sysDialer) dialIP(ctx context.Context, laddr, raddr *IPAddr) (*IPConn, error) { 117 network, proto, err := parseNetwork(ctx, sd.network, true) 118 if err != nil { 119 return nil, err 120 } 121 switch network { 122 case "ip", "ip4", "ip6": 123 default: 124 return nil, UnknownNetworkError(sd.network) 125 } 126 fd, err := internetSocket(ctx, network, laddr, raddr, syscall.SOCK_RAW, proto, "dial", sd.Dialer.Control) 127 if err != nil { 128 return nil, err 129 } 130 return newIPConn(fd), nil 131 } 132 133 func (sl *sysListener) listenIP(ctx context.Context, laddr *IPAddr) (*IPConn, error) { 134 network, proto, err := parseNetwork(ctx, sl.network, true) 135 if err != nil { 136 return nil, err 137 } 138 switch network { 139 case "ip", "ip4", "ip6": 140 default: 141 return nil, UnknownNetworkError(sl.network) 142 } 143 fd, err := internetSocket(ctx, network, laddr, nil, syscall.SOCK_RAW, proto, "listen", sl.ListenConfig.Control) 144 if err != nil { 145 return nil, err 146 } 147 return newIPConn(fd), nil 148 }