github.com/code-reading/golang@v0.0.0-20220303082512-ba5bc0e589a3/go/src/net/interface_bsd.go (about) 1 // Copyright 2011 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 darwin || dragonfly || freebsd || netbsd || openbsd 6 // +build darwin dragonfly freebsd netbsd openbsd 7 8 package net 9 10 import ( 11 "syscall" 12 13 "golang.org/x/net/route" 14 ) 15 16 // If the ifindex is zero, interfaceTable returns mappings of all 17 // network interfaces. Otherwise it returns a mapping of a specific 18 // interface. 19 func interfaceTable(ifindex int) ([]Interface, error) { 20 msgs, err := interfaceMessages(ifindex) 21 if err != nil { 22 return nil, err 23 } 24 n := len(msgs) 25 if ifindex != 0 { 26 n = 1 27 } 28 ift := make([]Interface, n) 29 n = 0 30 for _, m := range msgs { 31 switch m := m.(type) { 32 case *route.InterfaceMessage: 33 if ifindex != 0 && ifindex != m.Index { 34 continue 35 } 36 ift[n].Index = m.Index 37 ift[n].Name = m.Name 38 ift[n].Flags = linkFlags(m.Flags) 39 if sa, ok := m.Addrs[syscall.RTAX_IFP].(*route.LinkAddr); ok && len(sa.Addr) > 0 { 40 ift[n].HardwareAddr = make([]byte, len(sa.Addr)) 41 copy(ift[n].HardwareAddr, sa.Addr) 42 } 43 for _, sys := range m.Sys() { 44 if imx, ok := sys.(*route.InterfaceMetrics); ok { 45 ift[n].MTU = imx.MTU 46 break 47 } 48 } 49 n++ 50 if ifindex == m.Index { 51 return ift[:n], nil 52 } 53 } 54 } 55 return ift[:n], nil 56 } 57 58 func linkFlags(rawFlags int) Flags { 59 var f Flags 60 if rawFlags&syscall.IFF_UP != 0 { 61 f |= FlagUp 62 } 63 if rawFlags&syscall.IFF_BROADCAST != 0 { 64 f |= FlagBroadcast 65 } 66 if rawFlags&syscall.IFF_LOOPBACK != 0 { 67 f |= FlagLoopback 68 } 69 if rawFlags&syscall.IFF_POINTOPOINT != 0 { 70 f |= FlagPointToPoint 71 } 72 if rawFlags&syscall.IFF_MULTICAST != 0 { 73 f |= FlagMulticast 74 } 75 return f 76 } 77 78 // If the ifi is nil, interfaceAddrTable returns addresses for all 79 // network interfaces. Otherwise it returns addresses for a specific 80 // interface. 81 func interfaceAddrTable(ifi *Interface) ([]Addr, error) { 82 index := 0 83 if ifi != nil { 84 index = ifi.Index 85 } 86 msgs, err := interfaceMessages(index) 87 if err != nil { 88 return nil, err 89 } 90 ifat := make([]Addr, 0, len(msgs)) 91 for _, m := range msgs { 92 switch m := m.(type) { 93 case *route.InterfaceAddrMessage: 94 if index != 0 && index != m.Index { 95 continue 96 } 97 var mask IPMask 98 switch sa := m.Addrs[syscall.RTAX_NETMASK].(type) { 99 case *route.Inet4Addr: 100 mask = IPv4Mask(sa.IP[0], sa.IP[1], sa.IP[2], sa.IP[3]) 101 case *route.Inet6Addr: 102 mask = make(IPMask, IPv6len) 103 copy(mask, sa.IP[:]) 104 } 105 var ip IP 106 switch sa := m.Addrs[syscall.RTAX_IFA].(type) { 107 case *route.Inet4Addr: 108 ip = IPv4(sa.IP[0], sa.IP[1], sa.IP[2], sa.IP[3]) 109 case *route.Inet6Addr: 110 ip = make(IP, IPv6len) 111 copy(ip, sa.IP[:]) 112 } 113 if ip != nil && mask != nil { // NetBSD may contain route.LinkAddr 114 ifat = append(ifat, &IPNet{IP: ip, Mask: mask}) 115 } 116 } 117 } 118 return ifat, nil 119 }