From 5946f111827fa4e342a2e6e9c043c198d2e5cb03 Mon Sep 17 00:00:00 2001 From: Bhasker Hariharan Date: Thu, 9 Jul 2020 16:24:43 -0700 Subject: Add support for IP_HDRINCL IP option for raw sockets. Updates #2746 Fixes #3158 PiperOrigin-RevId: 320497190 --- pkg/sentry/socket/netstack/netstack.go | 11 ++++++++++- pkg/tcpip/tcpip.go | 5 +++++ pkg/tcpip/transport/raw/endpoint.go | 34 ++++++++++++++++++++++++++-------- 3 files changed, 41 insertions(+), 9 deletions(-) (limited to 'pkg') diff --git a/pkg/sentry/socket/netstack/netstack.go b/pkg/sentry/socket/netstack/netstack.go index e7d2c83d7..3b248a953 100644 --- a/pkg/sentry/socket/netstack/netstack.go +++ b/pkg/sentry/socket/netstack/netstack.go @@ -2112,13 +2112,22 @@ func setSockOptIP(t *kernel.Task, ep commonEndpoint, name int, optVal []byte) *s } return syserr.TranslateNetstackError(ep.SetSockOptBool(tcpip.ReceiveIPPacketInfoOption, v != 0)) + case linux.IP_HDRINCL: + if len(optVal) == 0 { + return nil + } + v, err := parseIntOrChar(optVal) + if err != nil { + return err + } + return syserr.TranslateNetstackError(ep.SetSockOptBool(tcpip.IPHdrIncludedOption, v != 0)) + case linux.IP_ADD_SOURCE_MEMBERSHIP, linux.IP_BIND_ADDRESS_NO_PORT, linux.IP_BLOCK_SOURCE, linux.IP_CHECKSUM, linux.IP_DROP_SOURCE_MEMBERSHIP, linux.IP_FREEBIND, - linux.IP_HDRINCL, linux.IP_IPSEC_POLICY, linux.IP_MINTTL, linux.IP_MSFILTER, diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go index 2f9872dc6..25534a10d 100644 --- a/pkg/tcpip/tcpip.go +++ b/pkg/tcpip/tcpip.go @@ -648,6 +648,11 @@ const ( // whether an IPv6 socket is to be restricted to sending and receiving // IPv6 packets only. V6OnlyOption + + // IPHdrIncludedOption is used by SetSockOpt to indicate for a raw + // endpoint that all packets being written have an IP header and the + // endpoint should not attach an IP header. + IPHdrIncludedOption ) // SockOptInt represents socket options which values have the int type. diff --git a/pkg/tcpip/transport/raw/endpoint.go b/pkg/tcpip/transport/raw/endpoint.go index 766c7648e..5b6e7d102 100644 --- a/pkg/tcpip/transport/raw/endpoint.go +++ b/pkg/tcpip/transport/raw/endpoint.go @@ -63,6 +63,7 @@ type endpoint struct { stack *stack.Stack `state:"manual"` waiterQueue *waiter.Queue associated bool + hdrIncluded bool // The following fields are used to manage the receive queue and are // protected by rcvMu. @@ -108,6 +109,7 @@ func newEndpoint(s *stack.Stack, netProto tcpip.NetworkProtocolNumber, transProt rcvBufSizeMax: 32 * 1024, sndBufSizeMax: 32 * 1024, associated: associated, + hdrIncluded: !associated, } // Override with stack defaults. @@ -182,10 +184,6 @@ func (e *endpoint) SetOwner(owner tcpip.PacketOwner) { // Read implements tcpip.Endpoint.Read. func (e *endpoint) Read(addr *tcpip.FullAddress) (buffer.View, tcpip.ControlMessages, *tcpip.Error) { - if !e.associated { - return buffer.View{}, tcpip.ControlMessages{}, tcpip.ErrInvalidOptionValue - } - e.rcvMu.Lock() // If there's no data to read, return that read would block or that the @@ -263,7 +261,7 @@ func (e *endpoint) write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-c // If this is an unassociated socket and callee provided a nonzero // destination address, route using that address. - if !e.associated { + if e.hdrIncluded { ip := header.IPv4(payloadBytes) if !ip.IsValid(len(payloadBytes)) { e.mu.RUnlock() @@ -353,7 +351,7 @@ func (e *endpoint) finishWrite(payloadBytes []byte, route *stack.Route) (int64, } } - if !e.associated { + if e.hdrIncluded { if err := route.WriteHeaderIncludedPacket(&stack.PacketBuffer{ Data: buffer.View(payloadBytes).ToVectorisedView(), }); err != nil { @@ -513,6 +511,13 @@ func (e *endpoint) SetSockOpt(opt interface{}) *tcpip.Error { // SetSockOptBool implements tcpip.Endpoint.SetSockOptBool. func (e *endpoint) SetSockOptBool(opt tcpip.SockOptBool, v bool) *tcpip.Error { + switch opt { + case tcpip.IPHdrIncludedOption: + e.mu.Lock() + e.hdrIncluded = v + e.mu.Unlock() + return nil + } return tcpip.ErrUnknownProtocolOption } @@ -577,6 +582,12 @@ func (e *endpoint) GetSockOptBool(opt tcpip.SockOptBool) (bool, *tcpip.Error) { case tcpip.KeepaliveEnabledOption: return false, nil + case tcpip.IPHdrIncludedOption: + e.mu.Lock() + v := e.hdrIncluded + e.mu.Unlock() + return v, nil + default: return false, tcpip.ErrUnknownProtocolOption } @@ -616,8 +627,15 @@ func (e *endpoint) GetSockOptInt(opt tcpip.SockOptInt) (int, *tcpip.Error) { func (e *endpoint) HandlePacket(route *stack.Route, pkt *stack.PacketBuffer) { e.rcvMu.Lock() - // Drop the packet if our buffer is currently full. - if e.rcvClosed { + // Drop the packet if our buffer is currently full or if this is an unassociated + // endpoint (i.e endpoint created w/ IPPROTO_RAW). Such endpoints are send only + // See: https://man7.org/linux/man-pages/man7/raw.7.html + // + // An IPPROTO_RAW socket is send only. If you really want to receive + // all IP packets, use a packet(7) socket with the ETH_P_IP protocol. + // Note that packet sockets don't reassemble IP fragments, unlike raw + // sockets. + if e.rcvClosed || !e.associated { e.rcvMu.Unlock() e.stack.Stats().DroppedPackets.Increment() e.stats.ReceiveErrors.ClosedReceiver.Increment() -- cgit v1.2.3