1 files changed, 208 insertions, 0 deletions
diff --git a/src/pkg/net/interface_linux.go b/src/pkg/net/interface_linux.go
new file mode 100644
index 000000000..5c9657834
--- /dev/null
+++ b/src/pkg/net/interface_linux.go
@@ -0,0 +1,208 @@
+// 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.
+
+// Network interface identification for Linux
+
+package net
+
+import (
+	"os"
+	"syscall"
+	"unsafe"
+)
+
+// IsUp returns true if ifi is up.
+func (ifi *Interface) IsUp() bool {
+	if ifi == nil {
+		return false
+	}
+	return ifi.rawFlags&syscall.IFF_UP != 0
+}
+
+// IsLoopback returns true if ifi is a loopback interface.
+func (ifi *Interface) IsLoopback() bool {
+	if ifi == nil {
+		return false
+	}
+	return ifi.rawFlags&syscall.IFF_LOOPBACK != 0
+}
+
+// CanBroadcast returns true if ifi supports a broadcast access
+// capability.
+func (ifi *Interface) CanBroadcast() bool {
+	if ifi == nil {
+		return false
+	}
+	return ifi.rawFlags&syscall.IFF_BROADCAST != 0
+}
+
+// IsPointToPoint returns true if ifi belongs to a point-to-point
+// link.
+func (ifi *Interface) IsPointToPoint() bool {
+	if ifi == nil {
+		return false
+	}
+	return ifi.rawFlags&syscall.IFF_POINTOPOINT != 0
+}
+
+// CanMulticast returns true if ifi supports a multicast access
+// capability.
+func (ifi *Interface) CanMulticast() bool {
+	if ifi == nil {
+		return false
+	}
+	return ifi.rawFlags&syscall.IFF_MULTICAST != 0
+}
+
+// If the ifindex is zero, interfaceTable returns mappings of all
+// network interfaces.  Otheriwse it returns a mapping of a specific
+// interface.
+func interfaceTable(ifindex int) ([]Interface, os.Error) {
+	var (
+		ift  []Interface
+		tab  []byte
+		msgs []syscall.NetlinkMessage
+		e    int
+	)
+
+	tab, e = syscall.NetlinkRIB(syscall.RTM_GETLINK, syscall.AF_UNSPEC)
+	if e != 0 {
+		return nil, os.NewSyscallError("netlink rib", e)
+	}
+
+	msgs, e = syscall.ParseNetlinkMessage(tab)
+	if e != 0 {
+		return nil, os.NewSyscallError("netlink message", e)
+	}
+
+	for _, m := range msgs {
+		switch m.Header.Type {
+		case syscall.NLMSG_DONE:
+			goto done
+		case syscall.RTM_NEWLINK:
+			ifim := (*syscall.IfInfomsg)(unsafe.Pointer(&m.Data[0]))
+			if ifindex == 0 || ifindex == int(ifim.Index) {
+				attrs, e := syscall.ParseNetlinkRouteAttr(&m)
+				if e != 0 {
+					return nil, os.NewSyscallError("netlink routeattr", e)
+				}
+				ifi := newLink(attrs, ifim)
+				ift = append(ift, ifi)
+			}
+		}
+	}
+
+done:
+	return ift, nil
+}
+
+func newLink(attrs []syscall.NetlinkRouteAttr, ifim *syscall.IfInfomsg) Interface {
+	ifi := Interface{Index: int(ifim.Index), rawFlags: int(ifim.Flags)}
+	for _, a := range attrs {
+		switch a.Attr.Type {
+		case syscall.IFLA_ADDRESS:
+			var nonzero bool
+			for _, b := range a.Value {
+				if b != 0 {
+					nonzero = true
+				}
+			}
+			if nonzero {
+				ifi.HardwareAddr = a.Value[:]
+			}
+		case syscall.IFLA_IFNAME:
+			ifi.Name = string(a.Value[:])
+		case syscall.IFLA_MTU:
+			ifi.MTU = int(uint32(a.Value[3])<<24 | uint32(a.Value[2])<<16 | uint32(a.Value[1])<<8 | uint32(a.Value[0]))
+		}
+	}
+	return ifi
+}
+
+// If the ifindex is zero, interfaceAddrTable returns addresses
+// for all network interfaces.  Otherwise it returns addresses
+// for a specific interface.
+func interfaceAddrTable(ifindex int) ([]Addr, os.Error) {
+	var (
+		ifat4 []Addr
+		ifat6 []Addr
+		tab   []byte
+		msgs4 []syscall.NetlinkMessage
+		msgs6 []syscall.NetlinkMessage
+		e     int
+		err   os.Error
+	)
+
+	tab, e = syscall.NetlinkRIB(syscall.RTM_GETADDR, syscall.AF_INET)
+	if e != 0 {
+		return nil, os.NewSyscallError("netlink rib", e)
+	}
+	msgs4, e = syscall.ParseNetlinkMessage(tab)
+	if e != 0 {
+		return nil, os.NewSyscallError("netlink message", e)
+	}
+	ifat4, err = addrTable(msgs4, ifindex)
+	if err != nil {
+		return nil, err
+	}
+
+	tab, e = syscall.NetlinkRIB(syscall.RTM_GETADDR, syscall.AF_INET6)
+	if e != 0 {
+		return nil, os.NewSyscallError("netlink rib", e)
+	}
+	msgs6, e = syscall.ParseNetlinkMessage(tab)
+	if e != 0 {
+		return nil, os.NewSyscallError("netlink message", e)
+	}
+	ifat6, err = addrTable(msgs6, ifindex)
+	if err != nil {
+		return nil, err
+	}
+
+	return append(ifat4, ifat6...), nil
+}
+
+func addrTable(msgs []syscall.NetlinkMessage, ifindex int) ([]Addr, os.Error) {
+	var ifat []Addr
+
+	for _, m := range msgs {
+		switch m.Header.Type {
+		case syscall.NLMSG_DONE:
+			goto done
+		case syscall.RTM_NEWADDR:
+			ifam := (*syscall.IfAddrmsg)(unsafe.Pointer(&m.Data[0]))
+			if ifindex == 0 || ifindex == int(ifam.Index) {
+				attrs, e := syscall.ParseNetlinkRouteAttr(&m)
+				if e != 0 {
+					return nil, os.NewSyscallError("netlink routeattr", e)
+				}
+				ifat = append(ifat, newAddr(attrs, int(ifam.Family))...)
+			}
+		}
+	}
+
+done:
+	return ifat, nil
+}
+
+func newAddr(attrs []syscall.NetlinkRouteAttr, family int) []Addr {
+	var ifat []Addr
+
+	for _, a := range attrs {
+		switch a.Attr.Type {
+		case syscall.IFA_ADDRESS:
+			ifa := IPAddr{}
+			switch family {
+			case syscall.AF_INET:
+				ifa.IP = IPv4(a.Value[0], a.Value[1], a.Value[2], a.Value[3])
+			case syscall.AF_INET6:
+				ifa.IP = make(IP, IPv6len)
+				copy(ifa.IP, a.Value[:])
+			}
+			ifat = append(ifat, ifa.toAddr())
+		}
+	}
+
+	return ifat
+}