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-rw-r--r--pkg/tcpip/network/ipv4/icmp.go20
-rw-r--r--pkg/tcpip/network/ipv6/icmp.go20
-rw-r--r--pkg/tcpip/stack/BUILD1
-rw-r--r--pkg/tcpip/stack/route.go24
-rw-r--r--pkg/tcpip/stack/stack_test.go48
-rw-r--r--pkg/tcpip/tests/integration/BUILD1
-rw-r--r--pkg/tcpip/tests/integration/multicast_broadcast_test.go208
-rw-r--r--pkg/tcpip/transport/udp/endpoint.go2
8 files changed, 299 insertions, 25 deletions
diff --git a/pkg/tcpip/network/ipv4/icmp.go b/pkg/tcpip/network/ipv4/icmp.go
index 83e71cb8c..94803a359 100644
--- a/pkg/tcpip/network/ipv4/icmp.go
+++ b/pkg/tcpip/network/ipv4/icmp.go
@@ -96,6 +96,26 @@ func (e *endpoint) handleICMP(r *stack.Route, pkt *stack.PacketBuffer) {
NetworkHeader: append(buffer.View(nil), pkt.NetworkHeader...),
})
+ remoteLinkAddr := r.RemoteLinkAddress
+
+ // As per RFC 1122 section 3.2.1.3, when a host sends any datagram, the IP
+ // source address MUST be one of its own IP addresses (but not a broadcast
+ // or multicast address).
+ localAddr := r.LocalAddress
+ if r.IsInboundBroadcast() || header.IsV4MulticastAddress(r.LocalAddress) {
+ localAddr = ""
+ }
+
+ r, err := r.Stack().FindRoute(e.NICID(), localAddr, r.RemoteAddress, ProtocolNumber, false /* multicastLoop */)
+ if err != nil {
+ // If we cannot find a route to the destination, silently drop the packet.
+ return
+ }
+ defer r.Release()
+
+ // Use the remote link address from the incoming packet.
+ r.ResolveWith(remoteLinkAddr)
+
vv := pkt.Data.Clone(nil)
vv.TrimFront(header.ICMPv4MinimumSize)
hdr := buffer.NewPrependable(int(r.MaxHeaderLength()) + header.ICMPv4MinimumSize)
diff --git a/pkg/tcpip/network/ipv6/icmp.go b/pkg/tcpip/network/ipv6/icmp.go
index 24600d877..ded91d83a 100644
--- a/pkg/tcpip/network/ipv6/icmp.go
+++ b/pkg/tcpip/network/ipv6/icmp.go
@@ -389,6 +389,26 @@ func (e *endpoint) handleICMP(r *stack.Route, pkt *stack.PacketBuffer, hasFragme
received.Invalid.Increment()
return
}
+
+ remoteLinkAddr := r.RemoteLinkAddress
+
+ // As per RFC 4291 section 2.7, multicast addresses must not be used as
+ // source addresses in IPv6 packets.
+ localAddr := r.LocalAddress
+ if header.IsV6MulticastAddress(r.LocalAddress) {
+ localAddr = ""
+ }
+
+ r, err := r.Stack().FindRoute(e.NICID(), localAddr, r.RemoteAddress, ProtocolNumber, false /* multicastLoop */)
+ if err != nil {
+ // If we cannot find a route to the destination, silently drop the packet.
+ return
+ }
+ defer r.Release()
+
+ // Use the link address from the source of the original packet.
+ r.ResolveWith(remoteLinkAddr)
+
pkt.Data.TrimFront(header.ICMPv6EchoMinimumSize)
hdr := buffer.NewPrependable(int(r.MaxHeaderLength()) + header.ICMPv6EchoMinimumSize)
packet := header.ICMPv6(hdr.Prepend(header.ICMPv6EchoMinimumSize))
diff --git a/pkg/tcpip/stack/BUILD b/pkg/tcpip/stack/BUILD
index 1c58bed2d..bfc7a0c7c 100644
--- a/pkg/tcpip/stack/BUILD
+++ b/pkg/tcpip/stack/BUILD
@@ -121,6 +121,7 @@ go_test(
"//pkg/tcpip/header",
"//pkg/tcpip/link/channel",
"//pkg/tcpip/link/loopback",
+ "//pkg/tcpip/network/arp",
"//pkg/tcpip/network/ipv4",
"//pkg/tcpip/network/ipv6",
"//pkg/tcpip/ports",
diff --git a/pkg/tcpip/stack/route.go b/pkg/tcpip/stack/route.go
index 91e0110f1..9ce0a2c22 100644
--- a/pkg/tcpip/stack/route.go
+++ b/pkg/tcpip/stack/route.go
@@ -110,6 +110,12 @@ func (r *Route) GSOMaxSize() uint32 {
return 0
}
+// ResolveWith immediately resolves a route with the specified remote link
+// address.
+func (r *Route) ResolveWith(addr tcpip.LinkAddress) {
+ r.RemoteLinkAddress = addr
+}
+
// Resolve attempts to resolve the link address if necessary. Returns ErrWouldBlock in
// case address resolution requires blocking, e.g. wait for ARP reply. Waker is
// notified when address resolution is complete (success or not).
@@ -279,12 +285,26 @@ func (r *Route) Stack() *Stack {
return r.ref.stack()
}
-// IsBroadcast returns true if the route is to send a broadcast packet.
-func (r *Route) IsBroadcast() bool {
+// IsOutboundBroadcast returns true if the route is for an outbound broadcast
+// packet.
+func (r *Route) IsOutboundBroadcast() bool {
// Only IPv4 has a notion of broadcast.
return r.directedBroadcast || r.RemoteAddress == header.IPv4Broadcast
}
+// IsInboundBroadcast returns true if the route is for an inbound broadcast
+// packet.
+func (r *Route) IsInboundBroadcast() bool {
+ // Only IPv4 has a notion of broadcast.
+ if r.LocalAddress == header.IPv4Broadcast {
+ return true
+ }
+
+ addr := r.ref.addrWithPrefix()
+ subnet := addr.Subnet()
+ return subnet.IsBroadcast(r.LocalAddress)
+}
+
// ReverseRoute returns new route with given source and destination address.
func (r *Route) ReverseRoute(src tcpip.Address, dst tcpip.Address) Route {
return Route{
diff --git a/pkg/tcpip/stack/stack_test.go b/pkg/tcpip/stack/stack_test.go
index 0b6deda02..fe1c1b8a4 100644
--- a/pkg/tcpip/stack/stack_test.go
+++ b/pkg/tcpip/stack/stack_test.go
@@ -21,6 +21,7 @@ import (
"bytes"
"fmt"
"math"
+ "net"
"sort"
"strings"
"testing"
@@ -34,6 +35,7 @@ import (
"gvisor.dev/gvisor/pkg/tcpip/header"
"gvisor.dev/gvisor/pkg/tcpip/link/channel"
"gvisor.dev/gvisor/pkg/tcpip/link/loopback"
+ "gvisor.dev/gvisor/pkg/tcpip/network/arp"
"gvisor.dev/gvisor/pkg/tcpip/network/ipv4"
"gvisor.dev/gvisor/pkg/tcpip/network/ipv6"
"gvisor.dev/gvisor/pkg/tcpip/stack"
@@ -3694,3 +3696,49 @@ func TestOutgoingSubnetBroadcast(t *testing.T) {
})
}
}
+
+func TestResolveWith(t *testing.T) {
+ const (
+ unspecifiedNICID = 0
+ nicID = 1
+ )
+
+ s := stack.New(stack.Options{
+ NetworkProtocols: []stack.NetworkProtocol{ipv4.NewProtocol(), arp.NewProtocol()},
+ })
+ ep := channel.New(0, defaultMTU, "")
+ ep.LinkEPCapabilities |= stack.CapabilityResolutionRequired
+ if err := s.CreateNIC(nicID, ep); err != nil {
+ t.Fatalf("CreateNIC(%d, _): %s", nicID, err)
+ }
+ addr := tcpip.ProtocolAddress{
+ Protocol: header.IPv4ProtocolNumber,
+ AddressWithPrefix: tcpip.AddressWithPrefix{
+ Address: tcpip.Address(net.ParseIP("192.168.1.58").To4()),
+ PrefixLen: 24,
+ },
+ }
+ if err := s.AddProtocolAddress(nicID, addr); err != nil {
+ t.Fatalf("AddProtocolAddress(%d, %+v): %s", nicID, addr, err)
+ }
+
+ s.SetRouteTable([]tcpip.Route{{Destination: header.IPv4EmptySubnet, NIC: nicID}})
+
+ remoteAddr := tcpip.Address(net.ParseIP("192.168.1.59").To4())
+ r, err := s.FindRoute(unspecifiedNICID, "" /* localAddr */, remoteAddr, header.IPv4ProtocolNumber, false /* multicastLoop */)
+ if err != nil {
+ t.Fatalf("FindRoute(%d, '', %s, %d): %s", unspecifiedNICID, remoteAddr, header.IPv4ProtocolNumber, err)
+ }
+ defer r.Release()
+
+ // Should initially require resolution.
+ if !r.IsResolutionRequired() {
+ t.Fatal("got r.IsResolutionRequired() = false, want = true")
+ }
+
+ // Manually resolving the route should no longer require resolution.
+ r.ResolveWith("\x01")
+ if r.IsResolutionRequired() {
+ t.Fatal("got r.IsResolutionRequired() = true, want = false")
+ }
+}
diff --git a/pkg/tcpip/tests/integration/BUILD b/pkg/tcpip/tests/integration/BUILD
index 7fff30462..6d52af98a 100644
--- a/pkg/tcpip/tests/integration/BUILD
+++ b/pkg/tcpip/tests/integration/BUILD
@@ -14,6 +14,7 @@ go_test(
"//pkg/tcpip/network/ipv4",
"//pkg/tcpip/network/ipv6",
"//pkg/tcpip/stack",
+ "//pkg/tcpip/transport/icmp",
"//pkg/tcpip/transport/udp",
"//pkg/waiter",
"@com_github_google_go_cmp//cmp:go_default_library",
diff --git a/pkg/tcpip/tests/integration/multicast_broadcast_test.go b/pkg/tcpip/tests/integration/multicast_broadcast_test.go
index d9b2d147a..0ff3a2b89 100644
--- a/pkg/tcpip/tests/integration/multicast_broadcast_test.go
+++ b/pkg/tcpip/tests/integration/multicast_broadcast_test.go
@@ -15,6 +15,7 @@
package integration_test
import (
+ "net"
"testing"
"github.com/google/go-cmp/cmp"
@@ -25,11 +26,195 @@ import (
"gvisor.dev/gvisor/pkg/tcpip/network/ipv4"
"gvisor.dev/gvisor/pkg/tcpip/network/ipv6"
"gvisor.dev/gvisor/pkg/tcpip/stack"
+ "gvisor.dev/gvisor/pkg/tcpip/transport/icmp"
"gvisor.dev/gvisor/pkg/tcpip/transport/udp"
"gvisor.dev/gvisor/pkg/waiter"
)
-const defaultMTU = 1280
+const (
+ defaultMTU = 1280
+ ttl = 255
+)
+
+var (
+ ipv4Addr = tcpip.AddressWithPrefix{
+ Address: tcpip.Address(net.ParseIP("192.168.1.58").To4()),
+ PrefixLen: 24,
+ }
+ ipv4Subnet = ipv4Addr.Subnet()
+ ipv4SubnetBcast = ipv4Subnet.Broadcast()
+
+ ipv6Addr = tcpip.AddressWithPrefix{
+ Address: tcpip.Address(net.ParseIP("200a::1").To16()),
+ PrefixLen: 64,
+ }
+ ipv6Subnet = ipv6Addr.Subnet()
+ ipv6SubnetBcast = ipv6Subnet.Broadcast()
+
+ // Remote addrs.
+ remoteIPv4Addr = tcpip.Address(net.ParseIP("10.0.0.1").To4())
+ remoteIPv6Addr = tcpip.Address(net.ParseIP("200b::1").To16())
+)
+
+// TestPingMulticastBroadcast tests that responding to an Echo Request destined
+// to a multicast or broadcast address uses a unicast source address for the
+// reply.
+func TestPingMulticastBroadcast(t *testing.T) {
+ const nicID = 1
+
+ rxIPv4ICMP := func(e *channel.Endpoint, dst tcpip.Address) {
+ totalLen := header.IPv4MinimumSize + header.ICMPv4MinimumSize
+ hdr := buffer.NewPrependable(totalLen)
+ pkt := header.ICMPv4(hdr.Prepend(header.ICMPv4MinimumSize))
+ pkt.SetType(header.ICMPv4Echo)
+ pkt.SetCode(0)
+ pkt.SetChecksum(0)
+ pkt.SetChecksum(^header.Checksum(pkt, 0))
+ ip := header.IPv4(hdr.Prepend(header.IPv4MinimumSize))
+ ip.Encode(&header.IPv4Fields{
+ IHL: header.IPv4MinimumSize,
+ TotalLength: uint16(totalLen),
+ Protocol: uint8(icmp.ProtocolNumber4),
+ TTL: ttl,
+ SrcAddr: remoteIPv4Addr,
+ DstAddr: dst,
+ })
+
+ e.InjectInbound(header.IPv4ProtocolNumber, &stack.PacketBuffer{
+ Data: hdr.View().ToVectorisedView(),
+ })
+ }
+
+ rxIPv6ICMP := func(e *channel.Endpoint, dst tcpip.Address) {
+ totalLen := header.IPv6MinimumSize + header.ICMPv6MinimumSize
+ hdr := buffer.NewPrependable(totalLen)
+ pkt := header.ICMPv6(hdr.Prepend(header.ICMPv6MinimumSize))
+ pkt.SetType(header.ICMPv6EchoRequest)
+ pkt.SetCode(0)
+ pkt.SetChecksum(0)
+ pkt.SetChecksum(header.ICMPv6Checksum(pkt, remoteIPv6Addr, dst, buffer.VectorisedView{}))
+ ip := header.IPv6(hdr.Prepend(header.IPv6MinimumSize))
+ ip.Encode(&header.IPv6Fields{
+ PayloadLength: header.ICMPv6MinimumSize,
+ NextHeader: uint8(icmp.ProtocolNumber6),
+ HopLimit: ttl,
+ SrcAddr: remoteIPv6Addr,
+ DstAddr: dst,
+ })
+
+ e.InjectInbound(header.IPv6ProtocolNumber, &stack.PacketBuffer{
+ Data: hdr.View().ToVectorisedView(),
+ })
+ }
+
+ tests := []struct {
+ name string
+ dstAddr tcpip.Address
+ }{
+ {
+ name: "IPv4 unicast",
+ dstAddr: ipv4Addr.Address,
+ },
+ {
+ name: "IPv4 directed broadcast",
+ dstAddr: ipv4SubnetBcast,
+ },
+ {
+ name: "IPv4 broadcast",
+ dstAddr: header.IPv4Broadcast,
+ },
+ {
+ name: "IPv4 all-systems multicast",
+ dstAddr: header.IPv4AllSystems,
+ },
+ {
+ name: "IPv6 unicast",
+ dstAddr: ipv6Addr.Address,
+ },
+ {
+ name: "IPv6 all-nodes multicast",
+ dstAddr: header.IPv6AllNodesMulticastAddress,
+ },
+ }
+
+ for _, test := range tests {
+ t.Run(test.name, func(t *testing.T) {
+ ipv4Proto := ipv4.NewProtocol()
+ ipv6Proto := ipv6.NewProtocol()
+ s := stack.New(stack.Options{
+ NetworkProtocols: []stack.NetworkProtocol{ipv4Proto, ipv6Proto},
+ TransportProtocols: []stack.TransportProtocol{icmp.NewProtocol4(), icmp.NewProtocol6()},
+ })
+ // We only expect a single packet in response to our ICMP Echo Request.
+ e := channel.New(1, defaultMTU, "")
+ if err := s.CreateNIC(nicID, e); err != nil {
+ t.Fatalf("CreateNIC(%d, _): %s", nicID, err)
+ }
+ ipv4ProtoAddr := tcpip.ProtocolAddress{Protocol: header.IPv4ProtocolNumber, AddressWithPrefix: ipv4Addr}
+ if err := s.AddProtocolAddress(nicID, ipv4ProtoAddr); err != nil {
+ t.Fatalf("AddProtocolAddress(%d, %+v): %s", nicID, ipv4ProtoAddr, err)
+ }
+ ipv6ProtoAddr := tcpip.ProtocolAddress{Protocol: header.IPv6ProtocolNumber, AddressWithPrefix: ipv6Addr}
+ if err := s.AddProtocolAddress(nicID, ipv6ProtoAddr); err != nil {
+ t.Fatalf("AddProtocolAddress(%d, %+v): %s", nicID, ipv6ProtoAddr, err)
+ }
+
+ // Default routes for IPv4 and IPv6 so ICMP can find a route to the remote
+ // node when attempting to send the ICMP Echo Reply.
+ s.SetRouteTable([]tcpip.Route{
+ tcpip.Route{
+ Destination: header.IPv6EmptySubnet,
+ NIC: nicID,
+ },
+ tcpip.Route{
+ Destination: header.IPv4EmptySubnet,
+ NIC: nicID,
+ },
+ })
+
+ var rxICMP func(*channel.Endpoint, tcpip.Address)
+ var expectedSrc tcpip.Address
+ var expectedDst tcpip.Address
+ var proto stack.NetworkProtocol
+ switch l := len(test.dstAddr); l {
+ case header.IPv4AddressSize:
+ rxICMP = rxIPv4ICMP
+ expectedSrc = ipv4Addr.Address
+ expectedDst = remoteIPv4Addr
+ proto = ipv4Proto
+ case header.IPv6AddressSize:
+ rxICMP = rxIPv6ICMP
+ expectedSrc = ipv6Addr.Address
+ expectedDst = remoteIPv6Addr
+ proto = ipv6Proto
+ default:
+ t.Fatalf("got unexpected address length = %d bytes", l)
+ }
+
+ rxICMP(e, test.dstAddr)
+ pkt, ok := e.Read()
+ if !ok {
+ t.Fatal("expected ICMP response")
+ }
+
+ if pkt.Route.LocalAddress != expectedSrc {
+ t.Errorf("got pkt.Route.LocalAddress = %s, want = %s", pkt.Route.LocalAddress, expectedSrc)
+ }
+ if pkt.Route.RemoteAddress != expectedDst {
+ t.Errorf("got pkt.Route.RemoteAddress = %s, want = %s", pkt.Route.RemoteAddress, expectedDst)
+ }
+
+ src, dst := proto.ParseAddresses(pkt.Pkt.NetworkHeader)
+ if src != expectedSrc {
+ t.Errorf("got pkt source = %s, want = %s", src, expectedSrc)
+ }
+ if dst != expectedDst {
+ t.Errorf("got pkt destination = %s, want = %s", dst, expectedDst)
+ }
+ })
+ }
+
+}
// TestIncomingMulticastAndBroadcast tests receiving a packet destined to some
// multicast or broadcast address.
@@ -38,31 +223,10 @@ func TestIncomingMulticastAndBroadcast(t *testing.T) {
nicID = 1
remotePort = 5555
localPort = 80
- ttl = 255
)
data := []byte{1, 2, 3, 4}
- // Local IPv4 subnet: 192.168.1.58/24
- ipv4Addr := tcpip.AddressWithPrefix{
- Address: "\xc0\xa8\x01\x3a",
- PrefixLen: 24,
- }
- ipv4Subnet := ipv4Addr.Subnet()
- ipv4SubnetBcast := ipv4Subnet.Broadcast()
-
- // Local IPv6 subnet: 200a::1/64
- ipv6Addr := tcpip.AddressWithPrefix{
- Address: "\x20\x0a\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01",
- PrefixLen: 64,
- }
- ipv6Subnet := ipv6Addr.Subnet()
- ipv6SubnetBcast := ipv6Subnet.Broadcast()
-
- // Remote addrs.
- remoteIPv4Addr := tcpip.Address("\x64\x0a\x7b\x18")
- remoteIPv6Addr := tcpip.Address("\x20\x0b\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02")
-
rxIPv4UDP := func(e *channel.Endpoint, dst tcpip.Address) {
payloadLen := header.UDPMinimumSize + len(data)
totalLen := header.IPv4MinimumSize + payloadLen
diff --git a/pkg/tcpip/transport/udp/endpoint.go b/pkg/tcpip/transport/udp/endpoint.go
index b7d735889..444b5b01c 100644
--- a/pkg/tcpip/transport/udp/endpoint.go
+++ b/pkg/tcpip/transport/udp/endpoint.go
@@ -499,7 +499,7 @@ func (e *endpoint) write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-c
resolve = route.Resolve
}
- if !e.broadcast && route.IsBroadcast() {
+ if !e.broadcast && route.IsOutboundBroadcast() {
return 0, nil, tcpip.ErrBroadcastDisabled
}