// Copyright 2011 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. //go:build darwin || dragonfly || freebsd || netbsd || openbsd package syscall import ( "runtime" "unsafe" ) var ( freebsdConfArch string // "machine $arch" line in kern.conftxt on freebsd minRoutingSockaddrLen = rsaAlignOf(0) ) // Round the length of a raw sockaddr up to align it properly. func rsaAlignOf(salen int) int { salign := sizeofPtr if darwin64Bit { // Darwin kernels require 32-bit aligned access to // routing facilities. salign = 4 } else if netbsd32Bit { // NetBSD 6 and beyond kernels require 64-bit aligned // access to routing facilities. salign = 8 } else if runtime.GOOS == "freebsd" { // In the case of kern.supported_archs="amd64 i386", // we need to know the underlying kernel's // architecture because the alignment for routing // facilities are set at the build time of the kernel. if freebsdConfArch == "amd64" { salign = 8 } } if salen == 0 { return salign } return (salen + salign - 1) & ^(salign - 1) } // parseSockaddrLink parses b as a datalink socket address. func parseSockaddrLink(b []byte) (*SockaddrDatalink, error) { if len(b) < 8 { return nil, EINVAL } sa, _, err := parseLinkLayerAddr(b[4:]) if err != nil { return nil, err } rsa := (*RawSockaddrDatalink)(unsafe.Pointer(&b[0])) sa.Len = rsa.Len sa.Family = rsa.Family sa.Index = rsa.Index return sa, nil } // parseLinkLayerAddr parses b as a datalink socket address in // conventional BSD kernel form. func parseLinkLayerAddr(b []byte) (*SockaddrDatalink, int, error) { // The encoding looks like the following: // +----------------------------+ // | Type (1 octet) | // +----------------------------+ // | Name length (1 octet) | // +----------------------------+ // | Address length (1 octet) | // +----------------------------+ // | Selector length (1 octet) | // +----------------------------+ // | Data (variable) | // +----------------------------+ type linkLayerAddr struct { Type byte Nlen byte Alen byte Slen byte } lla := (*linkLayerAddr)(unsafe.Pointer(&b[0])) l := 4 + int(lla.Nlen) + int(lla.Alen) + int(lla.Slen) if len(b) < l { return nil, 0, EINVAL } b = b[4:] sa := &SockaddrDatalink{Type: lla.Type, Nlen: lla.Nlen, Alen: lla.Alen, Slen: lla.Slen} for i := 0; len(sa.Data) > i && i < l-4; i++ { sa.Data[i] = int8(b[i]) } return sa, rsaAlignOf(l), nil } // parseSockaddrInet parses b as an internet socket address. func parseSockaddrInet(b []byte, family byte) (Sockaddr, error) { switch family { case AF_INET: if len(b) < SizeofSockaddrInet4 { return nil, EINVAL } rsa := (*RawSockaddrAny)(unsafe.Pointer(&b[0])) return anyToSockaddr(rsa) case AF_INET6: if len(b) < SizeofSockaddrInet6 { return nil, EINVAL } rsa := (*RawSockaddrAny)(unsafe.Pointer(&b[0])) return anyToSockaddr(rsa) default: return nil, EINVAL } } const ( offsetofInet4 = int(unsafe.Offsetof(RawSockaddrInet4{}.Addr)) offsetofInet6 = int(unsafe.Offsetof(RawSockaddrInet6{}.Addr)) ) // parseNetworkLayerAddr parses b as an internet socket address in // conventional BSD kernel form. func parseNetworkLayerAddr(b []byte, family byte) (Sockaddr, error) { // The encoding looks similar to the NLRI encoding. // +----------------------------+ // | Length (1 octet) | // +----------------------------+ // | Address prefix (variable) | // +----------------------------+ // // The differences between the kernel form and the NLRI // encoding are: // // - The length field of the kernel form indicates the prefix // length in bytes, not in bits // // - In the kernel form, zero value of the length field // doesn't mean 0.0.0.0/0 or ::/0 // // - The kernel form appends leading bytes to the prefix field // to make the tuple to be conformed with // the routing message boundary l := int(rsaAlignOf(int(b[0]))) if len(b) < l { return nil, EINVAL } // Don't reorder case expressions. // The case expressions for IPv6 must come first. switch { case b[0] == SizeofSockaddrInet6: sa := &SockaddrInet6{} copy(sa.Addr[:], b[offsetofInet6:]) return sa, nil case family == AF_INET6: sa := &SockaddrInet6{} if l-1 < offsetofInet6 { copy(sa.Addr[:], b[1:l]) } else { copy(sa.Addr[:], b[l-offsetofInet6:l]) } return sa, nil case b[0] == SizeofSockaddrInet4: sa := &SockaddrInet4{} copy(sa.Addr[:], b[offsetofInet4:]) return sa, nil default: // an old fashion, AF_UNSPEC or unknown means AF_INET sa := &SockaddrInet4{} if l-1 < offsetofInet4 { copy(sa.Addr[:], b[1:l]) } else { copy(sa.Addr[:], b[l-offsetofInet4:l]) } return sa, nil } } // RouteRIB returns routing information base, as known as RIB, // which consists of network facility information, states and // parameters. // // Deprecated: Use golang.org/x/net/route instead. func RouteRIB(facility, param int) ([]byte, error) { mib := []_C_int{CTL_NET, AF_ROUTE, 0, 0, _C_int(facility), _C_int(param)} // Find size. n := uintptr(0) if err := sysctl(mib, nil, &n, nil, 0); err != nil { return nil, err } if n == 0 { return nil, nil } tab := make([]byte, n) if err := sysctl(mib, &tab[0], &n, nil, 0); err != nil { return nil, err } return tab[:n], nil } // RoutingMessage represents a routing message. // // Deprecated: Use golang.org/x/net/route instead. type RoutingMessage interface { sockaddr() ([]Sockaddr, error) } const anyMessageLen = int(unsafe.Sizeof(anyMessage{})) type anyMessage struct { Msglen uint16 Version uint8 Type uint8 } // RouteMessage represents a routing message containing routing // entries. // // Deprecated: Use golang.org/x/net/route instead. type RouteMessage struct { Header RtMsghdr Data []byte } func (m *RouteMessage) sockaddr() ([]Sockaddr, error) { var sas [RTAX_MAX]Sockaddr b := m.Data[:] family := uint8(AF_UNSPEC) for i := uint(0); i < RTAX_MAX && len(b) >= minRoutingSockaddrLen; i++ { if m.Header.Addrs&(1<= minRoutingSockaddrLen; i++ { if m.Header.Addrs&(1<= anyMessageLen { nmsgs++ any := (*anyMessage)(unsafe.Pointer(&b[0])) if any.Version != RTM_VERSION { b = b[any.Msglen:] continue } if m := any.toRoutingMessage(b); m == nil { nskips++ } else { msgs = append(msgs, m) } b = b[any.Msglen:] } // We failed to parse any of the messages - version mismatch? if nmsgs != len(msgs)+nskips { return nil, EINVAL } return msgs, nil } // ParseRoutingSockaddr parses msg's payload as raw sockaddrs and // returns the slice containing the [Sockaddr] interfaces. // // Deprecated: Use golang.org/x/net/route instead. func ParseRoutingSockaddr(msg RoutingMessage) ([]Sockaddr, error) { sas, err := msg.sockaddr() if err != nil { return nil, err } return sas, nil }