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-rw-r--r--pkg/sentry/socket/netstack/netstack.go15
-rw-r--r--pkg/tcpip/ports/ports.go19
-rw-r--r--pkg/tcpip/ports/ports_test.go2
-rw-r--r--pkg/tcpip/transport/tcp/endpoint.go60
-rw-r--r--pkg/tcpip/transport/udp/endpoint.go2
-rw-r--r--test/syscalls/linux/socket_inet_loopback.cc38
-rw-r--r--test/syscalls/linux/socket_inet_loopback_nogotsan.cc65
-rw-r--r--test/syscalls/linux/socket_ipv4_udp_unbound.cc25
8 files changed, 189 insertions, 37 deletions
diff --git a/pkg/sentry/socket/netstack/netstack.go b/pkg/sentry/socket/netstack/netstack.go
index 0e5913b60..4d0e33696 100644
--- a/pkg/sentry/socket/netstack/netstack.go
+++ b/pkg/sentry/socket/netstack/netstack.go
@@ -803,7 +803,20 @@ func (s *socketOpsCommon) Bind(t *kernel.Task, sockaddr []byte) *syserr.Error {
}
// Issue the bind request to the endpoint.
- return syserr.TranslateNetstackError(s.Endpoint.Bind(addr))
+ err := s.Endpoint.Bind(addr)
+ if err == tcpip.ErrNoPortAvailable {
+ // Bind always returns EADDRINUSE irrespective of if the specified port was
+ // already bound or if an ephemeral port was requested but none were
+ // available.
+ //
+ // tcpip.ErrNoPortAvailable is mapped to EAGAIN in syserr package because
+ // UDP connect returns EAGAIN on ephemeral port exhaustion.
+ //
+ // TCP connect returns EADDRNOTAVAIL on ephemeral port exhaustion.
+ err = tcpip.ErrPortInUse
+ }
+
+ return syserr.TranslateNetstackError(err)
}
// Listen implements the linux syscall listen(2) for sockets backed by
diff --git a/pkg/tcpip/ports/ports.go b/pkg/tcpip/ports/ports.go
index f6d592eb5..d87193650 100644
--- a/pkg/tcpip/ports/ports.go
+++ b/pkg/tcpip/ports/ports.go
@@ -400,7 +400,11 @@ func (s *PortManager) isPortAvailableLocked(networks []tcpip.NetworkProtocolNumb
// reserved by another endpoint. If port is zero, ReservePort will search for
// an unreserved ephemeral port and reserve it, returning its value in the
// "port" return value.
-func (s *PortManager) ReservePort(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, flags Flags, bindToDevice tcpip.NICID, dest tcpip.FullAddress) (reservedPort uint16, err *tcpip.Error) {
+//
+// An optional testPort closure can be passed in which if provided will be used
+// to test if the picked port can be used. The function should return true if
+// the port is safe to use, false otherwise.
+func (s *PortManager) ReservePort(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, flags Flags, bindToDevice tcpip.NICID, dest tcpip.FullAddress, testPort func(port uint16) bool) (reservedPort uint16, err *tcpip.Error) {
s.mu.Lock()
defer s.mu.Unlock()
@@ -412,12 +416,23 @@ func (s *PortManager) ReservePort(networks []tcpip.NetworkProtocolNumber, transp
if !s.reserveSpecificPort(networks, transport, addr, port, flags, bindToDevice, dst) {
return 0, tcpip.ErrPortInUse
}
+ if testPort != nil && !testPort(port) {
+ s.releasePortLocked(networks, transport, addr, port, flags.Bits(), bindToDevice, dst)
+ return 0, tcpip.ErrPortInUse
+ }
return port, nil
}
// A port wasn't specified, so try to find one.
return s.PickEphemeralPort(func(p uint16) (bool, *tcpip.Error) {
- return s.reserveSpecificPort(networks, transport, addr, p, flags, bindToDevice, dst), nil
+ if !s.reserveSpecificPort(networks, transport, addr, p, flags, bindToDevice, dst) {
+ return false, nil
+ }
+ if testPort != nil && !testPort(p) {
+ s.releasePortLocked(networks, transport, addr, p, flags.Bits(), bindToDevice, dst)
+ return false, nil
+ }
+ return true, nil
})
}
diff --git a/pkg/tcpip/ports/ports_test.go b/pkg/tcpip/ports/ports_test.go
index 58db5868c..4bc949fd8 100644
--- a/pkg/tcpip/ports/ports_test.go
+++ b/pkg/tcpip/ports/ports_test.go
@@ -332,7 +332,7 @@ func TestPortReservation(t *testing.T) {
pm.ReleasePort(net, fakeTransNumber, test.ip, test.port, test.flags, test.device, test.dest)
continue
}
- gotPort, err := pm.ReservePort(net, fakeTransNumber, test.ip, test.port, test.flags, test.device, test.dest)
+ gotPort, err := pm.ReservePort(net, fakeTransNumber, test.ip, test.port, test.flags, test.device, test.dest, nil /* testPort */)
if err != test.want {
t.Fatalf("ReservePort(.., .., %s, %d, %+v, %d, %v) = %v, want %v", test.ip, test.port, test.flags, test.device, test.dest, err, test.want)
}
diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go
index 21a4b6e2f..9df22ac84 100644
--- a/pkg/tcpip/transport/tcp/endpoint.go
+++ b/pkg/tcpip/transport/tcp/endpoint.go
@@ -2169,7 +2169,7 @@ func (e *endpoint) connect(addr tcpip.FullAddress, handshake bool, run bool) *tc
if sameAddr && p == e.ID.RemotePort {
return false, nil
}
- if _, err := e.stack.ReservePort(netProtos, ProtocolNumber, e.ID.LocalAddress, p, e.portFlags, e.bindToDevice, addr); err != nil {
+ if _, err := e.stack.ReservePort(netProtos, ProtocolNumber, e.ID.LocalAddress, p, e.portFlags, e.bindToDevice, addr, nil /* testPort */); err != nil {
if err != tcpip.ErrPortInUse || !reuse {
return false, nil
}
@@ -2207,7 +2207,7 @@ func (e *endpoint) connect(addr tcpip.FullAddress, handshake bool, run bool) *tc
tcpEP.notifyProtocolGoroutine(notifyAbort)
tcpEP.UnlockUser()
// Now try and Reserve again if it fails then we skip.
- if _, err := e.stack.ReservePort(netProtos, ProtocolNumber, e.ID.LocalAddress, p, e.portFlags, e.bindToDevice, addr); err != nil {
+ if _, err := e.stack.ReservePort(netProtos, ProtocolNumber, e.ID.LocalAddress, p, e.portFlags, e.bindToDevice, addr, nil /* testPort */); err != nil {
return false, nil
}
}
@@ -2505,47 +2505,45 @@ func (e *endpoint) bindLocked(addr tcpip.FullAddress) (err *tcpip.Error) {
}
}
- port, err := e.stack.ReservePort(netProtos, ProtocolNumber, addr.Addr, addr.Port, e.portFlags, e.bindToDevice, tcpip.FullAddress{})
- if err != nil {
- return err
- }
-
- e.boundBindToDevice = e.bindToDevice
- e.boundPortFlags = e.portFlags
- e.isPortReserved = true
- e.effectiveNetProtos = netProtos
- e.ID.LocalPort = port
-
- // Any failures beyond this point must remove the port registration.
- defer func(portFlags ports.Flags, bindToDevice tcpip.NICID) {
- if err != nil {
- e.stack.ReleasePort(netProtos, ProtocolNumber, addr.Addr, port, portFlags, bindToDevice, tcpip.FullAddress{})
- e.isPortReserved = false
- e.effectiveNetProtos = nil
- e.ID.LocalPort = 0
- e.ID.LocalAddress = ""
- e.boundNICID = 0
- e.boundBindToDevice = 0
- e.boundPortFlags = ports.Flags{}
- }
- }(e.boundPortFlags, e.boundBindToDevice)
-
+ var nic tcpip.NICID
// If an address is specified, we must ensure that it's one of our
// local addresses.
if len(addr.Addr) != 0 {
- nic := e.stack.CheckLocalAddress(addr.NIC, netProto, addr.Addr)
+ nic = e.stack.CheckLocalAddress(addr.NIC, netProto, addr.Addr)
if nic == 0 {
return tcpip.ErrBadLocalAddress
}
-
- e.boundNICID = nic
e.ID.LocalAddress = addr.Addr
}
- if err := e.stack.CheckRegisterTransportEndpoint(e.boundNICID, e.effectiveNetProtos, ProtocolNumber, e.ID, e.boundPortFlags, e.boundBindToDevice); err != nil {
+ port, err := e.stack.ReservePort(netProtos, ProtocolNumber, addr.Addr, addr.Port, e.portFlags, e.bindToDevice, tcpip.FullAddress{}, func(p uint16) bool {
+ id := e.ID
+ id.LocalPort = p
+ // CheckRegisterTransportEndpoint should only return an error if there is a
+ // listening endpoint bound with the same id and portFlags and bindToDevice
+ // options.
+ //
+ // NOTE: Only listening and connected endpoint register with
+ // demuxer. Further connected endpoints always have a remote
+ // address/port. Hence this will only return an error if there is a matching
+ // listening endpoint.
+ if err := e.stack.CheckRegisterTransportEndpoint(nic, netProtos, ProtocolNumber, id, e.portFlags, e.bindToDevice); err != nil {
+ return false
+ }
+ return true
+ })
+ if err != nil {
return err
}
+ e.boundBindToDevice = e.bindToDevice
+ e.boundPortFlags = e.portFlags
+ // TODO(gvisor.dev/issue/3691): Add test to verify boundNICID is correct.
+ e.boundNICID = nic
+ e.isPortReserved = true
+ e.effectiveNetProtos = netProtos
+ e.ID.LocalPort = port
+
// Mark endpoint as bound.
e.setEndpointState(StateBound)
diff --git a/pkg/tcpip/transport/udp/endpoint.go b/pkg/tcpip/transport/udp/endpoint.go
index 73608783c..c33434b75 100644
--- a/pkg/tcpip/transport/udp/endpoint.go
+++ b/pkg/tcpip/transport/udp/endpoint.go
@@ -1226,7 +1226,7 @@ func (*endpoint) Accept() (tcpip.Endpoint, *waiter.Queue, *tcpip.Error) {
func (e *endpoint) registerWithStack(nicID tcpip.NICID, netProtos []tcpip.NetworkProtocolNumber, id stack.TransportEndpointID) (stack.TransportEndpointID, tcpip.NICID, *tcpip.Error) {
if e.ID.LocalPort == 0 {
- port, err := e.stack.ReservePort(netProtos, ProtocolNumber, id.LocalAddress, id.LocalPort, e.portFlags, e.bindToDevice, tcpip.FullAddress{})
+ port, err := e.stack.ReservePort(netProtos, ProtocolNumber, id.LocalAddress, id.LocalPort, e.portFlags, e.bindToDevice, tcpip.FullAddress{}, nil /* testPort */)
if err != nil {
return id, e.bindToDevice, err
}
diff --git a/test/syscalls/linux/socket_inet_loopback.cc b/test/syscalls/linux/socket_inet_loopback.cc
index c3b42682f..a62a10088 100644
--- a/test/syscalls/linux/socket_inet_loopback.cc
+++ b/test/syscalls/linux/socket_inet_loopback.cc
@@ -2573,6 +2573,44 @@ TEST_P(SocketMultiProtocolInetLoopbackTest, V4EphemeralPortReservedReuseAddr) {
SyscallSucceeds());
}
+TEST_P(SocketMultiProtocolInetLoopbackTest,
+ MultipleBindsAllowedNoListeningReuseAddr) {
+ const auto& param = GetParam();
+ // UDP sockets are allowed to bind/listen on the port w/ SO_REUSEADDR, for TCP
+ // this is only permitted if there is no other listening socket.
+ SKIP_IF(param.type != SOCK_STREAM);
+ // Bind the v4 loopback on a v4 socket.
+ const TestAddress& test_addr = V4Loopback();
+ sockaddr_storage bound_addr = test_addr.addr;
+ FileDescriptor bound_fd =
+ ASSERT_NO_ERRNO_AND_VALUE(Socket(test_addr.family(), param.type, 0));
+
+ ASSERT_THAT(setsockopt(bound_fd.get(), SOL_SOCKET, SO_REUSEADDR, &kSockOptOn,
+ sizeof(kSockOptOn)),
+ SyscallSucceeds());
+ ASSERT_THAT(bind(bound_fd.get(), reinterpret_cast<sockaddr*>(&bound_addr),
+ test_addr.addr_len),
+ SyscallSucceeds());
+ // Get the port that we bound.
+ socklen_t bound_addr_len = test_addr.addr_len;
+ ASSERT_THAT(
+ getsockname(bound_fd.get(), reinterpret_cast<sockaddr*>(&bound_addr),
+ &bound_addr_len),
+ SyscallSucceeds());
+
+ // Now create a socket and bind it to the same port, this should
+ // succeed since there is no listening socket for the same port.
+ FileDescriptor second_fd =
+ ASSERT_NO_ERRNO_AND_VALUE(Socket(test_addr.family(), param.type, 0));
+
+ ASSERT_THAT(setsockopt(second_fd.get(), SOL_SOCKET, SO_REUSEADDR, &kSockOptOn,
+ sizeof(kSockOptOn)),
+ SyscallSucceeds());
+ ASSERT_THAT(bind(second_fd.get(), reinterpret_cast<sockaddr*>(&bound_addr),
+ test_addr.addr_len),
+ SyscallSucceeds());
+}
+
TEST_P(SocketMultiProtocolInetLoopbackTest, PortReuseTwoSockets) {
auto const& param = GetParam();
TestAddress const& test_addr = V4Loopback();
diff --git a/test/syscalls/linux/socket_inet_loopback_nogotsan.cc b/test/syscalls/linux/socket_inet_loopback_nogotsan.cc
index 791e2bd51..1a0b53394 100644
--- a/test/syscalls/linux/socket_inet_loopback_nogotsan.cc
+++ b/test/syscalls/linux/socket_inet_loopback_nogotsan.cc
@@ -168,6 +168,71 @@ INSTANTIATE_TEST_SUITE_P(
TestParam{V6Loopback(), V6Loopback()}),
DescribeTestParam);
+struct ProtocolTestParam {
+ std::string description;
+ int type;
+};
+
+std::string DescribeProtocolTestParam(
+ ::testing::TestParamInfo<ProtocolTestParam> const& info) {
+ return info.param.description;
+}
+
+using SocketMultiProtocolInetLoopbackTest =
+ ::testing::TestWithParam<ProtocolTestParam>;
+
+TEST_P(SocketMultiProtocolInetLoopbackTest,
+ BindAvoidsListeningPortsReuseAddr_NoRandomSave) {
+ const auto& param = GetParam();
+ // UDP sockets are allowed to bind/listen on the port w/ SO_REUSEADDR, for TCP
+ // this is only permitted if there is no other listening socket.
+ SKIP_IF(param.type != SOCK_STREAM);
+
+ DisableSave ds; // Too many syscalls.
+
+ // A map of port to file descriptor binding the port.
+ std::map<uint16_t, FileDescriptor> listen_sockets;
+
+ // Exhaust all ephemeral ports.
+ while (true) {
+ // Bind the v4 loopback on a v4 socket.
+ TestAddress const& test_addr = V4Loopback();
+ sockaddr_storage bound_addr = test_addr.addr;
+ FileDescriptor bound_fd =
+ ASSERT_NO_ERRNO_AND_VALUE(Socket(test_addr.family(), param.type, 0));
+
+ ASSERT_THAT(setsockopt(bound_fd.get(), SOL_SOCKET, SO_REUSEADDR,
+ &kSockOptOn, sizeof(kSockOptOn)),
+ SyscallSucceeds());
+
+ int ret = bind(bound_fd.get(), reinterpret_cast<sockaddr*>(&bound_addr),
+ test_addr.addr_len);
+ if (ret != 0) {
+ ASSERT_EQ(errno, EADDRINUSE);
+ break;
+ }
+ // Get the port that we bound.
+ socklen_t bound_addr_len = test_addr.addr_len;
+ ASSERT_THAT(
+ getsockname(bound_fd.get(), reinterpret_cast<sockaddr*>(&bound_addr),
+ &bound_addr_len),
+ SyscallSucceeds());
+ uint16_t port = reinterpret_cast<sockaddr_in*>(&bound_addr)->sin_port;
+
+ // Newly bound port should not already be in use by a listening socket.
+ ASSERT_EQ(listen_sockets.find(port), listen_sockets.end());
+ auto fd = bound_fd.get();
+ listen_sockets.insert(std::make_pair(port, std::move(bound_fd)));
+ ASSERT_THAT(listen(fd, SOMAXCONN), SyscallSucceeds());
+ }
+}
+
+INSTANTIATE_TEST_SUITE_P(
+ AllFamilies, SocketMultiProtocolInetLoopbackTest,
+ ::testing::Values(ProtocolTestParam{"TCP", SOCK_STREAM},
+ ProtocolTestParam{"UDP", SOCK_DGRAM}),
+ DescribeProtocolTestParam);
+
} // namespace
} // namespace testing
diff --git a/test/syscalls/linux/socket_ipv4_udp_unbound.cc b/test/syscalls/linux/socket_ipv4_udp_unbound.cc
index bc005e2bb..cdc9c2266 100644
--- a/test/syscalls/linux/socket_ipv4_udp_unbound.cc
+++ b/test/syscalls/linux/socket_ipv4_udp_unbound.cc
@@ -2121,7 +2121,7 @@ TEST_P(IPv4UDPUnboundSocketTest, ReuseAddrReusePortDistribution) {
SyscallSucceedsWithValue(kMessageSize));
}
-// Check that connect returns EADDRNOTAVAIL when out of local ephemeral ports.
+// Check that connect returns EAGAIN when out of local ephemeral ports.
// We disable S/R because this test creates a large number of sockets.
TEST_P(IPv4UDPUnboundSocketTest, UDPConnectPortExhaustion_NoRandomSave) {
auto receiver1 = ASSERT_NO_ERRNO_AND_VALUE(NewSocket());
@@ -2154,6 +2154,29 @@ TEST_P(IPv4UDPUnboundSocketTest, UDPConnectPortExhaustion_NoRandomSave) {
}
}
+// Check that bind returns EADDRINUSE when out of local ephemeral ports.
+// We disable S/R because this test creates a large number of sockets.
+TEST_P(IPv4UDPUnboundSocketTest, UDPBindPortExhaustion_NoRandomSave) {
+ auto receiver1 = ASSERT_NO_ERRNO_AND_VALUE(NewSocket());
+ constexpr int kClients = 65536;
+ auto addr = V4Loopback();
+ // Disable cooperative S/R as we are making too many syscalls.
+ DisableSave ds;
+ std::vector<std::unique_ptr<FileDescriptor>> sockets;
+ for (int i = 0; i < kClients; i++) {
+ auto s = ASSERT_NO_ERRNO_AND_VALUE(NewSocket());
+
+ int ret =
+ bind(s->get(), reinterpret_cast<sockaddr*>(&addr.addr), addr.addr_len);
+ if (ret == 0) {
+ sockets.push_back(std::move(s));
+ continue;
+ }
+ ASSERT_THAT(ret, SyscallFailsWithErrno(EADDRINUSE));
+ break;
+ }
+}
+
// Test that socket will receive packet info control message.
TEST_P(IPv4UDPUnboundSocketTest, SetAndReceiveIPPKTINFO) {
// TODO(gvisor.dev/issue/1202): ioctl() is not supported by hostinet.