diff options
Diffstat (limited to 'pkg/tcpip')
-rw-r--r-- | pkg/tcpip/transport/udp/BUILD | 1 | ||||
-rw-r--r-- | pkg/tcpip/transport/udp/endpoint.go | 29 | ||||
-rw-r--r-- | pkg/tcpip/transport/udp/udp_test.go | 50 |
3 files changed, 73 insertions, 7 deletions
diff --git a/pkg/tcpip/transport/udp/BUILD b/pkg/tcpip/transport/udp/BUILD index c78549424..7ebae63d8 100644 --- a/pkg/tcpip/transport/udp/BUILD +++ b/pkg/tcpip/transport/udp/BUILD @@ -56,6 +56,7 @@ go_test( "//pkg/tcpip/network/ipv4", "//pkg/tcpip/network/ipv6", "//pkg/tcpip/stack", + "//pkg/tcpip/transport/icmp", "//pkg/waiter", ], ) diff --git a/pkg/tcpip/transport/udp/endpoint.go b/pkg/tcpip/transport/udp/endpoint.go index 57976d4e3..835dcc54e 100644 --- a/pkg/tcpip/transport/udp/endpoint.go +++ b/pkg/tcpip/transport/udp/endpoint.go @@ -429,7 +429,13 @@ func (e *endpoint) write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-c to := opts.To e.mu.RLock() - defer e.mu.RUnlock() + lockReleased := false + defer func() { + if lockReleased { + return + } + e.mu.RUnlock() + }() // If we've shutdown with SHUT_WR we are in an invalid state for sending. if e.shutdownFlags&tcpip.ShutdownWrite != 0 { @@ -475,7 +481,7 @@ func (e *endpoint) write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-c if e.state != StateConnected { err = tcpip.ErrInvalidEndpointState } - return + return ch, err } } else { // Reject destination address if it goes through a different @@ -541,7 +547,24 @@ func (e *endpoint) write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-c useDefaultTTL = false } - if err := sendUDP(route, buffer.View(v).ToVectorisedView(), e.ID.LocalPort, dstPort, ttl, useDefaultTTL, e.sendTOS, e.owner, e.noChecksum); err != nil { + localPort := e.ID.LocalPort + sendTOS := e.sendTOS + owner := e.owner + noChecksum := e.noChecksum + lockReleased = true + e.mu.RUnlock() + + // Do not hold lock when sending as loopback is synchronous and if the UDP + // datagram ends up generating an ICMP response then it can result in a + // deadlock where the ICMP response handling ends up acquiring this endpoint's + // mutex using e.mu.RLock() in endpoint.HandleControlPacket which can cause a + // deadlock if another caller is trying to acquire e.mu in exclusive mode w/ + // e.mu.Lock(). Since e.mu.Lock() prevents any new read locks to ensure the + // lock can be eventually acquired. + // + // See: https://golang.org/pkg/sync/#RWMutex for details on why recursive read + // locking is prohibited. + if err := sendUDP(route, buffer.View(v).ToVectorisedView(), localPort, dstPort, ttl, useDefaultTTL, sendTOS, owner, noChecksum); err != nil { return 0, nil, err } return int64(len(v)), nil, nil diff --git a/pkg/tcpip/transport/udp/udp_test.go b/pkg/tcpip/transport/udp/udp_test.go index 764ad0857..492e277a8 100644 --- a/pkg/tcpip/transport/udp/udp_test.go +++ b/pkg/tcpip/transport/udp/udp_test.go @@ -32,6 +32,7 @@ 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" ) @@ -54,6 +55,7 @@ const ( stackPort = 1234 testAddr = "\x0a\x00\x00\x02" testPort = 4096 + invalidPort = 8192 multicastAddr = "\xe8\x2b\xd3\xea" multicastV6Addr = "\xff\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" broadcastAddr = header.IPv4Broadcast @@ -295,7 +297,8 @@ func newDualTestContext(t *testing.T, mtu uint32) *testContext { t.Helper() return newDualTestContextWithOptions(t, mtu, stack.Options{ NetworkProtocols: []stack.NetworkProtocolFactory{ipv4.NewProtocol, ipv6.NewProtocol}, - TransportProtocols: []stack.TransportProtocolFactory{udp.NewProtocol}, + TransportProtocols: []stack.TransportProtocolFactory{udp.NewProtocol, icmp.NewProtocol6, icmp.NewProtocol4}, + HandleLocal: true, }) } @@ -972,7 +975,7 @@ func testFailingWrite(c *testContext, flow testFlow, wantErr *tcpip.Error) { // provided. func testWrite(c *testContext, flow testFlow, checkers ...checker.NetworkChecker) uint16 { c.t.Helper() - return testWriteInternal(c, flow, true, checkers...) + return testWriteAndVerifyInternal(c, flow, true, checkers...) } // testWriteWithoutDestination sends a packet of the given test flow from the @@ -981,10 +984,10 @@ func testWrite(c *testContext, flow testFlow, checkers ...checker.NetworkChecker // checker functions provided. func testWriteWithoutDestination(c *testContext, flow testFlow, checkers ...checker.NetworkChecker) uint16 { c.t.Helper() - return testWriteInternal(c, flow, false, checkers...) + return testWriteAndVerifyInternal(c, flow, false, checkers...) } -func testWriteInternal(c *testContext, flow testFlow, setDest bool, checkers ...checker.NetworkChecker) uint16 { +func testWriteNoVerify(c *testContext, flow testFlow, setDest bool) buffer.View { c.t.Helper() // Take a snapshot of the stats to validate them at the end of the test. epstats := c.ep.Stats().(*tcpip.TransportEndpointStats).Clone() @@ -1006,6 +1009,12 @@ func testWriteInternal(c *testContext, flow testFlow, setDest bool, checkers ... c.t.Fatalf("Bad number of bytes written: got %v, want %v", n, len(payload)) } c.checkEndpointWriteStats(1, epstats, err) + return payload +} + +func testWriteAndVerifyInternal(c *testContext, flow testFlow, setDest bool, checkers ...checker.NetworkChecker) uint16 { + c.t.Helper() + payload := testWriteNoVerify(c, flow, setDest) // Received the packet and check the payload. b := c.getPacketAndVerify(flow, checkers...) var udp header.UDP @@ -1150,6 +1159,39 @@ func TestV4WriteOnConnected(t *testing.T) { testWriteWithoutDestination(c, unicastV4) } +func TestWriteOnConnectedInvalidPort(t *testing.T) { + protocols := map[string]tcpip.NetworkProtocolNumber{ + "ipv4": ipv4.ProtocolNumber, + "ipv6": ipv6.ProtocolNumber, + } + for name, pn := range protocols { + t.Run(name, func(t *testing.T) { + c := newDualTestContext(t, defaultMTU) + defer c.cleanup() + + c.createEndpoint(pn) + if err := c.ep.Connect(tcpip.FullAddress{Addr: stackAddr, Port: invalidPort}); err != nil { + c.t.Fatalf("Connect failed: %s", err) + } + writeOpts := tcpip.WriteOptions{ + To: &tcpip.FullAddress{Addr: stackAddr, Port: invalidPort}, + } + payload := buffer.View(newPayload()) + n, _, err := c.ep.Write(tcpip.SlicePayload(payload), writeOpts) + if err != nil { + c.t.Fatalf("c.ep.Write(...) = %+s, want nil", err) + } + if got, want := n, int64(len(payload)); got != want { + c.t.Fatalf("c.ep.Write(...) wrote %d bytes, want %d bytes", got, want) + } + + if err := c.ep.LastError(); err != tcpip.ErrConnectionRefused { + c.t.Fatalf("expected c.ep.LastError() == ErrConnectionRefused, got: %+v", err) + } + }) + } +} + // TestWriteOnBoundToV4Multicast checks that we can send packets out of a socket // that is bound to a V4 multicast address. func TestWriteOnBoundToV4Multicast(t *testing.T) { |