diff options
Diffstat (limited to 'vendor/golang.org/x/net/route/address.go')
-rw-r--r-- | vendor/golang.org/x/net/route/address.go | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/vendor/golang.org/x/net/route/address.go b/vendor/golang.org/x/net/route/address.go new file mode 100644 index 000000000..a56909c10 --- /dev/null +++ b/vendor/golang.org/x/net/route/address.go @@ -0,0 +1,281 @@ +// Copyright 2016 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 route + +import "runtime" + +// An Addr represents an address associated with packet routing. +type Addr interface { + // Family returns an address family. + Family() int +} + +// A LinkAddr represents a link-layer address. +type LinkAddr struct { + Index int // interface index when attached + Name string // interface name when attached + Addr []byte // link-layer address when attached +} + +// Family implements the Family method of Addr interface. +func (a *LinkAddr) Family() int { return sysAF_LINK } + +func parseLinkAddr(b []byte) (Addr, error) { + if len(b) < 8 { + return nil, errInvalidAddr + } + _, a, err := parseKernelLinkAddr(sysAF_LINK, b[4:]) + if err != nil { + return nil, err + } + a.(*LinkAddr).Index = int(nativeEndian.Uint16(b[2:4])) + return a, nil +} + +// parseKernelLinkAddr parses b as a link-layer address in +// conventional BSD kernel form. +func parseKernelLinkAddr(_ int, b []byte) (int, Addr, error) { + // The encoding looks like the following: + // +----------------------------+ + // | Type (1 octet) | + // +----------------------------+ + // | Name length (1 octet) | + // +----------------------------+ + // | Address length (1 octet) | + // +----------------------------+ + // | Selector length (1 octet) | + // +----------------------------+ + // | Data (variable) | + // +----------------------------+ + // + // On some platforms, all-bit-one of length field means "don't + // care". + nlen, alen, slen := int(b[1]), int(b[2]), int(b[3]) + if nlen == 0xff { + nlen = 0 + } + if alen == 0xff { + alen = 0 + } + if slen == 0xff { + slen = 0 + } + l := 4 + nlen + alen + slen + if len(b) < l { + return 0, nil, errInvalidAddr + } + data := b[4:] + var name string + var addr []byte + if nlen > 0 { + name = string(data[:nlen]) + data = data[nlen:] + } + if alen > 0 { + addr = data[:alen] + data = data[alen:] + } + return l, &LinkAddr{Name: name, Addr: addr}, nil +} + +// An Inet4Addr represents an internet address for IPv4. +type Inet4Addr struct { + IP [4]byte // IP address +} + +// Family implements the Family method of Addr interface. +func (a *Inet4Addr) Family() int { return sysAF_INET } + +// An Inet6Addr represents an internet address for IPv6. +type Inet6Addr struct { + IP [16]byte // IP address + ZoneID int // zone identifier +} + +// Family implements the Family method of Addr interface. +func (a *Inet6Addr) Family() int { return sysAF_INET6 } + +// parseInetAddr parses b as an internet address for IPv4 or IPv6. +func parseInetAddr(af int, b []byte) (Addr, error) { + switch af { + case sysAF_INET: + if len(b) < 16 { + return nil, errInvalidAddr + } + a := &Inet4Addr{} + copy(a.IP[:], b[4:8]) + return a, nil + case sysAF_INET6: + if len(b) < 28 { + return nil, errInvalidAddr + } + a := &Inet6Addr{ZoneID: int(nativeEndian.Uint32(b[24:28]))} + copy(a.IP[:], b[8:24]) + if a.IP[0] == 0xfe && a.IP[1]&0xc0 == 0x80 || a.IP[0] == 0xff && (a.IP[1]&0x0f == 0x01 || a.IP[1]&0x0f == 0x02) { + // KAME based IPv6 protocol stack usually + // embeds the interface index in the + // interface-local or link-local address as + // the kernel-internal form. + id := int(bigEndian.Uint16(a.IP[2:4])) + if id != 0 { + a.ZoneID = id + a.IP[2], a.IP[3] = 0, 0 + } + } + return a, nil + default: + return nil, errInvalidAddr + } +} + +// parseKernelInetAddr parses b as an internet address in conventional +// BSD kernel form. +func parseKernelInetAddr(af int, b []byte) (int, Addr, 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(b[0]) + if runtime.GOOS == "darwin" { + // On Darwn, an address in the kernel form is also + // used as a message filler. + if l == 0 || len(b) > roundup(l) { + l = roundup(l) + } + } else { + l = roundup(l) + } + if len(b) < l { + return 0, nil, errInvalidAddr + } + // Don't reorder case expressions. + // The case expressions for IPv6 must come first. + const ( + off4 = 4 // offset of in_addr + off6 = 8 // offset of in6_addr + ) + switch { + case b[0] == 28: // size of sockaddr_in6 + a := &Inet6Addr{} + copy(a.IP[:], b[off6:off6+16]) + return int(b[0]), a, nil + case af == sysAF_INET6: + a := &Inet6Addr{} + if l-1 < off6 { + copy(a.IP[:], b[1:l]) + } else { + copy(a.IP[:], b[l-off6:l]) + } + return int(b[0]), a, nil + case b[0] == 16: // size of sockaddr_in + a := &Inet4Addr{} + copy(a.IP[:], b[off4:off4+4]) + return int(b[0]), a, nil + default: // an old fashion, AF_UNSPEC or unknown means AF_INET + a := &Inet4Addr{} + if l-1 < off4 { + copy(a.IP[:], b[1:l]) + } else { + copy(a.IP[:], b[l-off4:l]) + } + return int(b[0]), a, nil + } +} + +// A DefaultAddr represents an address of various operating +// system-specific features. +type DefaultAddr struct { + af int + Raw []byte // raw format of address +} + +// Family implements the Family method of Addr interface. +func (a *DefaultAddr) Family() int { return a.af } + +func parseDefaultAddr(b []byte) (Addr, error) { + if len(b) < 2 || len(b) < int(b[0]) { + return nil, errInvalidAddr + } + a := &DefaultAddr{af: int(b[1]), Raw: b[:b[0]]} + return a, nil +} + +func parseAddrs(attrs uint, fn func(int, []byte) (int, Addr, error), b []byte) ([]Addr, error) { + var as [sysRTAX_MAX]Addr + af := int(sysAF_UNSPEC) + for i := uint(0); i < sysRTAX_MAX && len(b) >= roundup(0); i++ { + if attrs&(1<<i) == 0 { + continue + } + if i <= sysRTAX_BRD { + switch b[1] { + case sysAF_LINK: + a, err := parseLinkAddr(b) + if err != nil { + return nil, err + } + as[i] = a + l := roundup(int(b[0])) + if len(b) < l { + return nil, errMessageTooShort + } + b = b[l:] + case sysAF_INET, sysAF_INET6: + af = int(b[1]) + a, err := parseInetAddr(af, b) + if err != nil { + return nil, err + } + as[i] = a + l := roundup(int(b[0])) + if len(b) < l { + return nil, errMessageTooShort + } + b = b[l:] + default: + l, a, err := fn(af, b) + if err != nil { + return nil, err + } + as[i] = a + ll := roundup(l) + if len(b) < ll { + b = b[l:] + } else { + b = b[ll:] + } + } + } else { + a, err := parseDefaultAddr(b) + if err != nil { + return nil, err + } + as[i] = a + l := roundup(int(b[0])) + if len(b) < l { + return nil, errMessageTooShort + } + b = b[l:] + } + } + return as[:], nil +} |