From c611dbc5a7399922588e3fd99b22bda19f684afe Mon Sep 17 00:00:00 2001
From: Ian Gudger <igudger@google.com>
Date: Fri, 15 Feb 2019 18:39:10 -0800
Subject: Implement IP_MULTICAST_IF.
This allows setting a default send interface for IPv4 multicast. IPv6 support
will come later.
PiperOrigin-RevId: 234251379
Change-Id: I65922341cd8b8880f690fae3eeb7ddfa47c8c173
---
pkg/sentry/socket/epsocket/epsocket.go | 66 ++++++++++++++++++++++++++--------
1 file changed, 52 insertions(+), 14 deletions(-)
(limited to 'pkg/sentry/socket')
diff --git a/pkg/sentry/socket/epsocket/epsocket.go b/pkg/sentry/socket/epsocket/epsocket.go
index 3a9d1182f..3392ac645 100644
--- a/pkg/sentry/socket/epsocket/epsocket.go
+++ b/pkg/sentry/socket/epsocket/epsocket.go
@@ -27,7 +27,6 @@ package epsocket
import (
"bytes"
"math"
- "strings"
"sync"
"syscall"
"time"
@@ -191,6 +190,15 @@ func New(t *kernel.Task, family int, skType transport.SockType, queue *waiter.Qu
var sockAddrInetSize = int(binary.Size(linux.SockAddrInet{}))
var sockAddrInet6Size = int(binary.Size(linux.SockAddrInet6{}))
+// bytesToIPAddress converts an IPv4 or IPv6 address from the user to the
+// netstack representation taking any addresses into account.
+func bytesToIPAddress(addr []byte) tcpip.Address {
+ if bytes.Equal(addr, make([]byte, 4)) || bytes.Equal(addr, make([]byte, 16)) {
+ return ""
+ }
+ return tcpip.Address(addr)
+}
+
// GetAddress reads an sockaddr struct from the given address and converts it
// to the FullAddress format. It supports AF_UNIX, AF_INET and AF_INET6
// addresses.
@@ -231,12 +239,9 @@ func GetAddress(sfamily int, addr []byte) (tcpip.FullAddress, *syserr.Error) {
binary.Unmarshal(addr[:sockAddrInetSize], usermem.ByteOrder, &a)
out := tcpip.FullAddress{
- Addr: tcpip.Address(a.Addr[:]),
+ Addr: bytesToIPAddress(a.Addr[:]),
Port: ntohs(a.Port),
}
- if out.Addr == "\x00\x00\x00\x00" {
- out.Addr = ""
- }
return out, nil
case linux.AF_INET6:
@@ -247,15 +252,12 @@ func GetAddress(sfamily int, addr []byte) (tcpip.FullAddress, *syserr.Error) {
binary.Unmarshal(addr[:sockAddrInet6Size], usermem.ByteOrder, &a)
out := tcpip.FullAddress{
- Addr: tcpip.Address(a.Addr[:]),
+ Addr: bytesToIPAddress(a.Addr[:]),
Port: ntohs(a.Port),
}
if isLinkLocal(out.Addr) {
out.NIC = tcpip.NICID(a.Scope_id)
}
- if out.Addr == tcpip.Address(strings.Repeat("\x00", 16)) {
- out.Addr = ""
- }
return out, nil
default:
@@ -864,6 +866,30 @@ func getSockOptIP(t *kernel.Task, ep commonEndpoint, name, outLen int) (interfac
return int32(v), nil
+ case linux.IP_MULTICAST_IF:
+ if outLen < inetMulticastRequestSize {
+ return nil, syserr.ErrInvalidArgument
+ }
+
+ var v tcpip.MulticastInterfaceOption
+ if err := ep.GetSockOpt(&v); err != nil {
+ return nil, syserr.TranslateNetstackError(err)
+ }
+
+ a, _ := ConvertAddress(linux.AF_INET, tcpip.FullAddress{Addr: v.InterfaceAddr})
+
+ rv := linux.InetMulticastRequestWithNIC{
+ linux.InetMulticastRequest{
+ InterfaceAddr: a.(linux.SockAddrInet).Addr,
+ },
+ int32(v.NIC),
+ }
+
+ if outLen >= inetMulticastRequestWithNICSize {
+ return rv, nil
+ }
+ return rv.InetMulticastRequest, nil
+
default:
emitUnimplementedEventIP(t, name)
}
@@ -1148,7 +1174,9 @@ func setSockOptIP(t *kernel.Task, ep commonEndpoint, name int, optVal []byte) *s
}
return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.AddMembershipOption{
- NIC: tcpip.NICID(req.InterfaceIndex),
+ NIC: tcpip.NICID(req.InterfaceIndex),
+ // TODO: Change AddMembership to use the standard
+ // any address representation.
InterfaceAddr: tcpip.Address(req.InterfaceAddr[:]),
MulticastAddr: tcpip.Address(req.MulticastAddr[:]),
}))
@@ -1160,19 +1188,29 @@ func setSockOptIP(t *kernel.Task, ep commonEndpoint, name int, optVal []byte) *s
}
return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.RemoveMembershipOption{
- NIC: tcpip.NICID(req.InterfaceIndex),
+ NIC: tcpip.NICID(req.InterfaceIndex),
+ // TODO: Change DropMembership to use the standard
+ // any address representation.
InterfaceAddr: tcpip.Address(req.InterfaceAddr[:]),
MulticastAddr: tcpip.Address(req.MulticastAddr[:]),
}))
case linux.IP_MULTICAST_IF:
+ req, err := copyInMulticastRequest(optVal)
+ if err != nil {
+ return err
+ }
+
+ return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.MulticastInterfaceOption{
+ NIC: tcpip.NICID(req.InterfaceIndex),
+ InterfaceAddr: bytesToIPAddress(req.InterfaceAddr[:]),
+ }))
+
+ case linux.MCAST_JOIN_GROUP:
// FIXME: Disallow IP-level multicast group options by
// default. These will need to be supported by appropriately plumbing
// the level through to the network stack (if at all). However, we
// still allow setting TTL, and multicast-enable/disable type options.
- fallthrough
- case linux.MCAST_JOIN_GROUP:
- // FIXME: Implement MCAST_JOIN_GROUP.
t.Kernel().EmitUnimplementedEvent(t)
return syserr.ErrInvalidArgument
--
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