gcc/libgo/go/syscall/netlink_linux.go
Ian Lance Taylor f8d9fa9e80 libgo, compiler: Upgrade libgo to Go 1.4, except for runtime.
This upgrades all of libgo other than the runtime package to
the Go 1.4 release.  In Go 1.4 much of the runtime was
rewritten into Go.  Merging that code will take more time and
will not change the API, so I'm putting it off for now.

There are a few runtime changes anyhow, to accomodate other
packages that rely on minor modifications to the runtime
support.

The compiler changes slightly to add a one-bit flag to each
type descriptor kind that is stored directly in an interface,
which for gccgo is currently only pointer types.  Another
one-bit flag (gcprog) is reserved because it is used by the gc
compiler, but gccgo does not currently use it.

There is another error check in the compiler since I ran
across it during testing.

gotools/:
	* Makefile.am (go_cmd_go_files): Sort entries.  Add generate.go.
	* Makefile.in: Rebuild.

From-SVN: r219627
2015-01-15 00:27:56 +00:00

179 lines
4.7 KiB
Go

// 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.
// Netlink sockets and messages
package syscall
import "unsafe"
// Round the length of a netlink message up to align it properly.
func nlmAlignOf(msglen int) int {
return (msglen + NLMSG_ALIGNTO - 1) & ^(NLMSG_ALIGNTO - 1)
}
// Round the length of a netlink route attribute up to align it
// properly.
func rtaAlignOf(attrlen int) int {
return (attrlen + RTA_ALIGNTO - 1) & ^(RTA_ALIGNTO - 1)
}
// NetlinkRouteRequest represents a request message to receive routing
// and link states from the kernel.
type NetlinkRouteRequest struct {
Header NlMsghdr
Data RtGenmsg
}
func (rr *NetlinkRouteRequest) toWireFormat() []byte {
b := make([]byte, rr.Header.Len)
*(*uint32)(unsafe.Pointer(&b[0:4][0])) = rr.Header.Len
*(*uint16)(unsafe.Pointer(&b[4:6][0])) = rr.Header.Type
*(*uint16)(unsafe.Pointer(&b[6:8][0])) = rr.Header.Flags
*(*uint32)(unsafe.Pointer(&b[8:12][0])) = rr.Header.Seq
*(*uint32)(unsafe.Pointer(&b[12:16][0])) = rr.Header.Pid
b[16] = byte(rr.Data.Family)
return b
}
func newNetlinkRouteRequest(proto, seq, family int) []byte {
rr := &NetlinkRouteRequest{}
rr.Header.Len = uint32(NLMSG_HDRLEN + SizeofRtGenmsg)
rr.Header.Type = uint16(proto)
rr.Header.Flags = NLM_F_DUMP | NLM_F_REQUEST
rr.Header.Seq = uint32(seq)
rr.Data.Family = uint8(family)
return rr.toWireFormat()
}
// NetlinkRIB returns routing information base, as known as RIB, which
// consists of network facility information, states and parameters.
func NetlinkRIB(proto, family int) ([]byte, error) {
s, err := Socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE)
if err != nil {
return nil, err
}
defer Close(s)
lsa := &SockaddrNetlink{Family: AF_NETLINK}
if err := Bind(s, lsa); err != nil {
return nil, err
}
wb := newNetlinkRouteRequest(proto, 1, family)
if err := Sendto(s, wb, 0, lsa); err != nil {
return nil, err
}
var tab []byte
rbNew := make([]byte, Getpagesize())
done:
for {
rb := rbNew
nr, _, err := Recvfrom(s, rb, 0)
if err != nil {
return nil, err
}
if nr < NLMSG_HDRLEN {
return nil, EINVAL
}
rb = rb[:nr]
tab = append(tab, rb...)
msgs, err := ParseNetlinkMessage(rb)
if err != nil {
return nil, err
}
for _, m := range msgs {
lsa, err := Getsockname(s)
if err != nil {
return nil, err
}
switch v := lsa.(type) {
case *SockaddrNetlink:
if m.Header.Seq != 1 || m.Header.Pid != v.Pid {
return nil, EINVAL
}
default:
return nil, EINVAL
}
if m.Header.Type == NLMSG_DONE {
break done
}
if m.Header.Type == NLMSG_ERROR {
return nil, EINVAL
}
}
}
return tab, nil
}
// NetlinkMessage represents a netlink message.
type NetlinkMessage struct {
Header NlMsghdr
Data []byte
}
// ParseNetlinkMessage parses b as an array of netlink messages and
// returns the slice containing the NetlinkMessage structures.
func ParseNetlinkMessage(b []byte) ([]NetlinkMessage, error) {
var msgs []NetlinkMessage
for len(b) >= NLMSG_HDRLEN {
h, dbuf, dlen, err := netlinkMessageHeaderAndData(b)
if err != nil {
return nil, err
}
m := NetlinkMessage{Header: *h, Data: dbuf[:int(h.Len)-NLMSG_HDRLEN]}
msgs = append(msgs, m)
b = b[dlen:]
}
return msgs, nil
}
func netlinkMessageHeaderAndData(b []byte) (*NlMsghdr, []byte, int, error) {
h := (*NlMsghdr)(unsafe.Pointer(&b[0]))
if int(h.Len) < NLMSG_HDRLEN || int(h.Len) > len(b) {
return nil, nil, 0, EINVAL
}
return h, b[NLMSG_HDRLEN:], nlmAlignOf(int(h.Len)), nil
}
// NetlinkRouteAttr represents a netlink route attribute.
type NetlinkRouteAttr struct {
Attr RtAttr
Value []byte
}
// ParseNetlinkRouteAttr parses m's payload as an array of netlink
// route attributes and returns the slice containing the
// NetlinkRouteAttr structures.
func ParseNetlinkRouteAttr(m *NetlinkMessage) ([]NetlinkRouteAttr, error) {
var b []byte
switch m.Header.Type {
case RTM_NEWLINK, RTM_DELLINK:
b = m.Data[SizeofIfInfomsg:]
case RTM_NEWADDR, RTM_DELADDR:
b = m.Data[SizeofIfAddrmsg:]
case RTM_NEWROUTE, RTM_DELROUTE:
b = m.Data[SizeofRtMsg:]
default:
return nil, EINVAL
}
var attrs []NetlinkRouteAttr
for len(b) >= SizeofRtAttr {
a, vbuf, alen, err := netlinkRouteAttrAndValue(b)
if err != nil {
return nil, err
}
ra := NetlinkRouteAttr{Attr: *a, Value: vbuf[:int(a.Len)-SizeofRtAttr]}
attrs = append(attrs, ra)
b = b[alen:]
}
return attrs, nil
}
func netlinkRouteAttrAndValue(b []byte) (*RtAttr, []byte, int, error) {
a := (*RtAttr)(unsafe.Pointer(&b[0]))
if int(a.Len) < SizeofRtAttr || int(a.Len) > len(b) {
return nil, nil, 0, EINVAL
}
return a, b[SizeofRtAttr:], rtaAlignOf(int(a.Len)), nil
}