From 0a8ae4b32f0dbc0b2a84c3f07c8c98e855a8f5fa Mon Sep 17 00:00:00 2001 From: Ghanan Gowripalan Date: Mon, 10 Aug 2020 16:20:39 -0700 Subject: Populate IPPacketInfo with destination address IPPacketInfo.DestinationAddr should hold the destination of the IP packet, not the source. This change fixes that bug. PiperOrigin-RevId: 325910766 --- pkg/tcpip/checker/BUILD | 1 + pkg/tcpip/checker/checker.go | 26 +++++-- pkg/tcpip/tcpip.go | 2 +- pkg/tcpip/transport/udp/endpoint.go | 9 ++- pkg/tcpip/transport/udp/udp_test.go | 99 ++++++++++++++++++++++++ test/syscalls/linux/socket_ipv4_udp_unbound.cc | 100 +++++++++++++++++++++++++ 6 files changed, 226 insertions(+), 11 deletions(-) diff --git a/pkg/tcpip/checker/BUILD b/pkg/tcpip/checker/BUILD index ed434807f..c984470e6 100644 --- a/pkg/tcpip/checker/BUILD +++ b/pkg/tcpip/checker/BUILD @@ -12,5 +12,6 @@ go_library( "//pkg/tcpip/buffer", "//pkg/tcpip/header", "//pkg/tcpip/seqnum", + "@com_github_google_go_cmp//cmp:go_default_library", ], ) diff --git a/pkg/tcpip/checker/checker.go b/pkg/tcpip/checker/checker.go index ee264b726..1e5f5abf2 100644 --- a/pkg/tcpip/checker/checker.go +++ b/pkg/tcpip/checker/checker.go @@ -21,6 +21,7 @@ import ( "reflect" "testing" + "github.com/google/go-cmp/cmp" "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/buffer" "gvisor.dev/gvisor/pkg/tcpip/header" @@ -169,10 +170,9 @@ func ReceiveTClass(want uint32) ControlMessagesChecker { return func(t *testing.T, cm tcpip.ControlMessages) { t.Helper() if !cm.HasTClass { - t.Fatalf("got cm.HasTClass = %t, want cm.TClass = %d", cm.HasTClass, want) - } - if got := cm.TClass; got != want { - t.Fatalf("got cm.TClass = %d, want %d", got, want) + t.Errorf("got cm.HasTClass = %t, want = true", cm.HasTClass) + } else if got := cm.TClass; got != want { + t.Errorf("got cm.TClass = %d, want %d", got, want) } } } @@ -182,10 +182,22 @@ func ReceiveTOS(want uint8) ControlMessagesChecker { return func(t *testing.T, cm tcpip.ControlMessages) { t.Helper() if !cm.HasTOS { - t.Fatalf("got cm.HasTOS = %t, want cm.TOS = %d", cm.HasTOS, want) + t.Errorf("got cm.HasTOS = %t, want = true", cm.HasTOS) + } else if got := cm.TOS; got != want { + t.Errorf("got cm.TOS = %d, want %d", got, want) } - if got := cm.TOS; got != want { - t.Fatalf("got cm.TOS = %d, want %d", got, want) + } +} + +// ReceiveIPPacketInfo creates a checker that checks the PacketInfo field in +// ControlMessages. +func ReceiveIPPacketInfo(want tcpip.IPPacketInfo) ControlMessagesChecker { + return func(t *testing.T, cm tcpip.ControlMessages) { + t.Helper() + if !cm.HasIPPacketInfo { + t.Errorf("got cm.HasIPPacketInfo = %t, want = true", cm.HasIPPacketInfo) + } else if diff := cmp.Diff(want, cm.PacketInfo); diff != "" { + t.Errorf("IPPacketInfo mismatch (-want +got):\n%s", diff) } } } diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go index 45f59b60f..091bc5281 100644 --- a/pkg/tcpip/tcpip.go +++ b/pkg/tcpip/tcpip.go @@ -968,7 +968,7 @@ type IPPacketInfo struct { // LocalAddr is the local address. LocalAddr Address - // DestinationAddr is the destination address. + // DestinationAddr is the destination address found in the IP header. DestinationAddr Address } diff --git a/pkg/tcpip/transport/udp/endpoint.go b/pkg/tcpip/transport/udp/endpoint.go index 444b5b01c..4a2b6c03a 100644 --- a/pkg/tcpip/transport/udp/endpoint.go +++ b/pkg/tcpip/transport/udp/endpoint.go @@ -1444,13 +1444,16 @@ func (e *endpoint) HandlePacket(r *stack.Route, id stack.TransportEndpointID, pk switch r.NetProto { case header.IPv4ProtocolNumber: packet.tos, _ = header.IPv4(pkt.NetworkHeader).TOS() - packet.packetInfo.LocalAddr = r.LocalAddress - packet.packetInfo.DestinationAddr = r.RemoteAddress - packet.packetInfo.NIC = r.NICID() case header.IPv6ProtocolNumber: packet.tos, _ = header.IPv6(pkt.NetworkHeader).TOS() } + // TODO(gvisor.dev/issue/3556): r.LocalAddress may be a multicast or broadcast + // address. packetInfo.LocalAddr should hold a unicast address that can be + // used to respond to the incoming packet. + packet.packetInfo.LocalAddr = r.LocalAddress + packet.packetInfo.DestinationAddr = r.LocalAddress + packet.packetInfo.NIC = r.NICID() packet.timestamp = e.stack.Clock().NowNanoseconds() e.rcvMu.Unlock() diff --git a/pkg/tcpip/transport/udp/udp_test.go b/pkg/tcpip/transport/udp/udp_test.go index 66e8911c8..1a32622ca 100644 --- a/pkg/tcpip/transport/udp/udp_test.go +++ b/pkg/tcpip/transport/udp/udp_test.go @@ -1309,6 +1309,105 @@ func TestReadIncrementsPacketsReceived(t *testing.T) { } } +func TestReadIPPacketInfo(t *testing.T) { + tests := []struct { + name string + proto tcpip.NetworkProtocolNumber + flow testFlow + expectedLocalAddr tcpip.Address + expectedDestAddr tcpip.Address + }{ + { + name: "IPv4 unicast", + proto: header.IPv4ProtocolNumber, + flow: unicastV4, + expectedLocalAddr: stackAddr, + expectedDestAddr: stackAddr, + }, + { + name: "IPv4 multicast", + proto: header.IPv4ProtocolNumber, + flow: multicastV4, + // This should actually be a unicast address assigned to the interface. + // + // TODO(gvisor.dev/issue/3556): This check is validating incorrect + // behaviour. We still include the test so that once the bug is + // resolved, this test will start to fail and the individual tasked + // with fixing this bug knows to also fix this test :). + expectedLocalAddr: multicastAddr, + expectedDestAddr: multicastAddr, + }, + { + name: "IPv4 broadcast", + proto: header.IPv4ProtocolNumber, + flow: broadcast, + // This should actually be a unicast address assigned to the interface. + // + // TODO(gvisor.dev/issue/3556): This check is validating incorrect + // behaviour. We still include the test so that once the bug is + // resolved, this test will start to fail and the individual tasked + // with fixing this bug knows to also fix this test :). + expectedLocalAddr: broadcastAddr, + expectedDestAddr: broadcastAddr, + }, + { + name: "IPv6 unicast", + proto: header.IPv6ProtocolNumber, + flow: unicastV6, + expectedLocalAddr: stackV6Addr, + expectedDestAddr: stackV6Addr, + }, + { + name: "IPv6 multicast", + proto: header.IPv6ProtocolNumber, + flow: multicastV6, + // This should actually be a unicast address assigned to the interface. + // + // TODO(gvisor.dev/issue/3556): This check is validating incorrect + // behaviour. We still include the test so that once the bug is + // resolved, this test will start to fail and the individual tasked + // with fixing this bug knows to also fix this test :). + expectedLocalAddr: multicastV6Addr, + expectedDestAddr: multicastV6Addr, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + c := newDualTestContext(t, defaultMTU) + defer c.cleanup() + + c.createEndpoint(test.proto) + + bindAddr := tcpip.FullAddress{Port: stackPort} + if err := c.ep.Bind(bindAddr); err != nil { + t.Fatalf("Bind(%+v): %s", bindAddr, err) + } + + if test.flow.isMulticast() { + ifoptSet := tcpip.AddMembershipOption{NIC: 1, MulticastAddr: test.flow.getMcastAddr()} + if err := c.ep.SetSockOpt(ifoptSet); err != nil { + c.t.Fatalf("SetSockOpt(%+v): %s:", ifoptSet, err) + } + } + + if err := c.ep.SetSockOptBool(tcpip.ReceiveIPPacketInfoOption, true); err != nil { + t.Fatalf("c.ep.SetSockOptBool(tcpip.ReceiveIPPacketInfoOption, true): %s", err) + } + + testRead(c, test.flow, checker.ReceiveIPPacketInfo(tcpip.IPPacketInfo{ + NIC: 1, + LocalAddr: test.expectedLocalAddr, + DestinationAddr: test.expectedDestAddr, + })) + + if got := c.s.Stats().UDP.PacketsReceived.Value(); got != 1 { + t.Fatalf("Read did not increment PacketsReceived: got = %d, want = 1", got) + } + }) + } +} + func TestWriteIncrementsPacketsSent(t *testing.T) { c := newDualTestContext(t, defaultMTU) defer c.cleanup() diff --git a/test/syscalls/linux/socket_ipv4_udp_unbound.cc b/test/syscalls/linux/socket_ipv4_udp_unbound.cc index de0f5f01b..bc005e2bb 100644 --- a/test/syscalls/linux/socket_ipv4_udp_unbound.cc +++ b/test/syscalls/linux/socket_ipv4_udp_unbound.cc @@ -2452,5 +2452,105 @@ TEST_P(IPv4UDPUnboundSocketTest, SetSocketSendBuf) { ASSERT_EQ(quarter_sz, val); } + +TEST_P(IPv4UDPUnboundSocketTest, IpMulticastIPPacketInfo) { + auto sender_socket = ASSERT_NO_ERRNO_AND_VALUE(NewSocket()); + auto receiver_socket = ASSERT_NO_ERRNO_AND_VALUE(NewSocket()); + + // Bind the first FD to the loopback. This is an alternative to + // IP_MULTICAST_IF for setting the default send interface. + auto sender_addr = V4Loopback(); + ASSERT_THAT( + bind(sender_socket->get(), reinterpret_cast(&sender_addr.addr), + sender_addr.addr_len), + SyscallSucceeds()); + + // Bind the second FD to the v4 any address to ensure that we can receive the + // multicast packet. + auto receiver_addr = V4Any(); + ASSERT_THAT(bind(receiver_socket->get(), + reinterpret_cast(&receiver_addr.addr), + receiver_addr.addr_len), + SyscallSucceeds()); + socklen_t receiver_addr_len = receiver_addr.addr_len; + ASSERT_THAT(getsockname(receiver_socket->get(), + reinterpret_cast(&receiver_addr.addr), + &receiver_addr_len), + SyscallSucceeds()); + EXPECT_EQ(receiver_addr_len, receiver_addr.addr_len); + + // Register to receive multicast packets. + ip_mreqn group = {}; + group.imr_multiaddr.s_addr = inet_addr(kMulticastAddress); + group.imr_ifindex = ASSERT_NO_ERRNO_AND_VALUE(InterfaceIndex("lo")); + ASSERT_THAT(setsockopt(receiver_socket->get(), IPPROTO_IP, IP_ADD_MEMBERSHIP, + &group, sizeof(group)), + SyscallSucceeds()); + + // Register to receive IP packet info. + const int one = 1; + ASSERT_THAT(setsockopt(receiver_socket->get(), IPPROTO_IP, IP_PKTINFO, &one, + sizeof(one)), + SyscallSucceeds()); + + // Send a multicast packet. + auto send_addr = V4Multicast(); + reinterpret_cast(&send_addr.addr)->sin_port = + reinterpret_cast(&receiver_addr.addr)->sin_port; + char send_buf[200]; + RandomizeBuffer(send_buf, sizeof(send_buf)); + ASSERT_THAT( + RetryEINTR(sendto)(sender_socket->get(), send_buf, sizeof(send_buf), 0, + reinterpret_cast(&send_addr.addr), + send_addr.addr_len), + SyscallSucceedsWithValue(sizeof(send_buf))); + + // Check that we received the multicast packet. + msghdr recv_msg = {}; + iovec recv_iov = {}; + char recv_buf[sizeof(send_buf)]; + char recv_cmsg_buf[CMSG_SPACE(sizeof(in_pktinfo))] = {}; + size_t cmsg_data_len = sizeof(in_pktinfo); + recv_iov.iov_base = recv_buf; + recv_iov.iov_len = sizeof(recv_buf); + recv_msg.msg_iov = &recv_iov; + recv_msg.msg_iovlen = 1; + recv_msg.msg_controllen = CMSG_LEN(cmsg_data_len); + recv_msg.msg_control = recv_cmsg_buf; + ASSERT_THAT(RetryEINTR(recvmsg)(receiver_socket->get(), &recv_msg, 0), + SyscallSucceedsWithValue(sizeof(send_buf))); + EXPECT_EQ(0, memcmp(send_buf, recv_buf, sizeof(send_buf))); + + // Check the IP_PKTINFO control message. + cmsghdr* cmsg = CMSG_FIRSTHDR(&recv_msg); + ASSERT_NE(cmsg, nullptr); + EXPECT_EQ(cmsg->cmsg_len, CMSG_LEN(cmsg_data_len)); + EXPECT_EQ(cmsg->cmsg_level, IPPROTO_IP); + EXPECT_EQ(cmsg->cmsg_type, IP_PKTINFO); + + // Get loopback index. + ifreq ifr = {}; + absl::SNPrintF(ifr.ifr_name, IFNAMSIZ, "lo"); + ASSERT_THAT(ioctl(receiver_socket->get(), SIOCGIFINDEX, &ifr), + SyscallSucceeds()); + ASSERT_NE(ifr.ifr_ifindex, 0); + + in_pktinfo received_pktinfo = {}; + memcpy(&received_pktinfo, CMSG_DATA(cmsg), sizeof(in_pktinfo)); + EXPECT_EQ(received_pktinfo.ipi_ifindex, ifr.ifr_ifindex); + if (IsRunningOnGvisor()) { + // This should actually be a unicast address assigned to the interface. + // + // TODO(gvisor.dev/issue/3556): This check is validating incorrect + // behaviour. We still include the test so that once the bug is + // resolved, this test will start to fail and the individual tasked + // with fixing this bug knows to also fix this test :). + EXPECT_EQ(received_pktinfo.ipi_spec_dst.s_addr, group.imr_multiaddr.s_addr); + } else { + EXPECT_EQ(received_pktinfo.ipi_spec_dst.s_addr, htonl(INADDR_LOOPBACK)); + } + EXPECT_EQ(received_pktinfo.ipi_addr.s_addr, group.imr_multiaddr.s_addr); +} + } // namespace testing } // namespace gvisor -- cgit v1.2.3