diff options
Diffstat (limited to 'src/syscall/route_bsd.go')
-rw-r--r-- | src/syscall/route_bsd.go | 364 |
1 files changed, 364 insertions, 0 deletions
diff --git a/src/syscall/route_bsd.go b/src/syscall/route_bsd.go new file mode 100644 index 0000000..b364eea --- /dev/null +++ b/src/syscall/route_bsd.go @@ -0,0 +1,364 @@ +// 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. + +// +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 <length, prefix> 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<<i) == 0 { + continue + } + rsa := (*RawSockaddr)(unsafe.Pointer(&b[0])) + switch rsa.Family { + case AF_LINK: + sa, err := parseSockaddrLink(b) + if err != nil { + return nil, err + } + sas[i] = sa + b = b[rsaAlignOf(int(rsa.Len)):] + case AF_INET, AF_INET6: + sa, err := parseSockaddrInet(b, rsa.Family) + if err != nil { + return nil, err + } + sas[i] = sa + b = b[rsaAlignOf(int(rsa.Len)):] + family = rsa.Family + default: + sa, err := parseNetworkLayerAddr(b, family) + if err != nil { + return nil, err + } + sas[i] = sa + b = b[rsaAlignOf(int(b[0])):] + } + } + return sas[:], nil +} + +// InterfaceMessage represents a routing message containing +// network interface entries. +// +// Deprecated: Use golang.org/x/net/route instead. +type InterfaceMessage struct { + Header IfMsghdr + Data []byte +} + +func (m *InterfaceMessage) sockaddr() ([]Sockaddr, error) { + var sas [RTAX_MAX]Sockaddr + if m.Header.Addrs&RTA_IFP == 0 { + return nil, nil + } + sa, err := parseSockaddrLink(m.Data[:]) + if err != nil { + return nil, err + } + sas[RTAX_IFP] = sa + return sas[:], nil +} + +// InterfaceAddrMessage represents a routing message containing +// network interface address entries. +// +// Deprecated: Use golang.org/x/net/route instead. +type InterfaceAddrMessage struct { + Header IfaMsghdr + Data []byte +} + +func (m *InterfaceAddrMessage) 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<<i) == 0 { + continue + } + rsa := (*RawSockaddr)(unsafe.Pointer(&b[0])) + switch rsa.Family { + case AF_LINK: + sa, err := parseSockaddrLink(b) + if err != nil { + return nil, err + } + sas[i] = sa + b = b[rsaAlignOf(int(rsa.Len)):] + case AF_INET, AF_INET6: + sa, err := parseSockaddrInet(b, rsa.Family) + if err != nil { + return nil, err + } + sas[i] = sa + b = b[rsaAlignOf(int(rsa.Len)):] + family = rsa.Family + default: + sa, err := parseNetworkLayerAddr(b, family) + if err != nil { + return nil, err + } + sas[i] = sa + b = b[rsaAlignOf(int(b[0])):] + } + } + return sas[:], nil +} + +// ParseRoutingMessage parses b as routing messages and returns the +// slice containing the RoutingMessage interfaces. +// +// Deprecated: Use golang.org/x/net/route instead. +func ParseRoutingMessage(b []byte) (msgs []RoutingMessage, err error) { + nmsgs, nskips := 0, 0 + for len(b) >= 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 +} |