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      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef SANDBOX_LINUX_SECCOMP_BPF_BPF_TESTS_H__
      6 #define SANDBOX_LINUX_SECCOMP_BPF_BPF_TESTS_H__
      7 
      8 #include <memory>
      9 
     10 #include "base/logging.h"
     11 #include "base/macros.h"
     12 #include "build/build_config.h"
     13 #include "sandbox/linux/seccomp-bpf/bpf_tester_compatibility_delegate.h"
     14 #include "sandbox/linux/tests/unit_tests.h"
     15 
     16 namespace sandbox {
     17 
     18 // BPF_TEST_C() is a special version of SANDBOX_TEST(). It runs a test function
     19 // in a sub-process, under a seccomp-bpf policy specified in
     20 // |bpf_policy_class_name| without failing on configurations that are allowed
     21 // to not support seccomp-bpf in their kernels.
     22 // This is the preferred format for new BPF tests. |bpf_policy_class_name| is a
     23 // class name  (which will be default-constructed) that implements the
     24 // Policy interface.
     25 // The test function's body can simply follow. Test functions should use
     26 // the BPF_ASSERT macros defined below, not GTEST's macros. The use of
     27 // CHECK* macros is supported but less robust.
     28 #define BPF_TEST_C(test_case_name, test_name, bpf_policy_class_name)     \
     29   BPF_DEATH_TEST_C(                                                      \
     30       test_case_name, test_name, DEATH_SUCCESS(), bpf_policy_class_name)
     31 
     32 // Identical to BPF_TEST_C but allows to specify the nature of death.
     33 #define BPF_DEATH_TEST_C(                                            \
     34     test_case_name, test_name, death, bpf_policy_class_name)         \
     35   void BPF_TEST_C_##test_name();                                     \
     36   TEST(test_case_name, DISABLE_ON_TSAN(test_name)) {                 \
     37     sandbox::SandboxBPFTestRunner bpf_test_runner(                   \
     38         new sandbox::BPFTesterSimpleDelegate<bpf_policy_class_name>( \
     39             BPF_TEST_C_##test_name));                                \
     40     sandbox::UnitTests::RunTestInProcess(&bpf_test_runner, death);   \
     41   }                                                                  \
     42   void BPF_TEST_C_##test_name()
     43 
     44 // This form of BPF_TEST is a little verbose and should be reserved for complex
     45 // tests where a lot of control is required.
     46 // |bpf_tester_delegate_class| must be a classname implementing the
     47 // BPFTesterDelegate interface.
     48 #define BPF_TEST_D(test_case_name, test_name, bpf_tester_delegate_class)     \
     49   BPF_DEATH_TEST_D(                                                          \
     50       test_case_name, test_name, DEATH_SUCCESS(), bpf_tester_delegate_class)
     51 
     52 // Identical to BPF_TEST_D but allows to specify the nature of death.
     53 #define BPF_DEATH_TEST_D(                                          \
     54     test_case_name, test_name, death, bpf_tester_delegate_class)   \
     55   TEST(test_case_name, DISABLE_ON_TSAN(test_name)) {               \
     56     sandbox::SandboxBPFTestRunner bpf_test_runner(                 \
     57         new bpf_tester_delegate_class());                          \
     58     sandbox::UnitTests::RunTestInProcess(&bpf_test_runner, death); \
     59   }
     60 
     61 // Assertions are handled exactly the same as with a normal SANDBOX_TEST()
     62 #define BPF_ASSERT SANDBOX_ASSERT
     63 #define BPF_ASSERT_EQ(x, y) BPF_ASSERT((x) == (y))
     64 #define BPF_ASSERT_NE(x, y) BPF_ASSERT((x) != (y))
     65 #define BPF_ASSERT_LT(x, y) BPF_ASSERT((x) < (y))
     66 #define BPF_ASSERT_GT(x, y) BPF_ASSERT((x) > (y))
     67 #define BPF_ASSERT_LE(x, y) BPF_ASSERT((x) <= (y))
     68 #define BPF_ASSERT_GE(x, y) BPF_ASSERT((x) >= (y))
     69 
     70 // This form of BPF_TEST is now discouraged (but still allowed) in favor of
     71 // BPF_TEST_D and BPF_TEST_C.
     72 // The |policy| parameter should be a Policy subclass.
     73 // BPF_TEST() takes a C++ data type as an fourth parameter. A variable
     74 // of this type will be allocated and a pointer to it will be
     75 // available within the test function as "BPF_AUX". The pointer will
     76 // also be passed as an argument to the policy's constructor. Policies
     77 // would typically use it as an argument to SandboxBPF::Trap(), if
     78 // they want to communicate data between the BPF_TEST() and a Trap()
     79 // function. The life-time of this object is the same as the life-time
     80 // of the process running under the seccomp-bpf policy.
     81 // |aux| must not be void.
     82 #define BPF_TEST(test_case_name, test_name, policy, aux) \
     83   BPF_DEATH_TEST(test_case_name, test_name, DEATH_SUCCESS(), policy, aux)
     84 
     85 // A BPF_DEATH_TEST is just the same as a BPF_TEST, but it assumes that the
     86 // test will fail with a particular known error condition. Use the DEATH_XXX()
     87 // macros from unit_tests.h to specify the expected error condition.
     88 #define BPF_DEATH_TEST(test_case_name, test_name, death, policy, aux) \
     89   void BPF_TEST_##test_name(aux* BPF_AUX);                            \
     90   TEST(test_case_name, DISABLE_ON_TSAN(test_name)) {                  \
     91     sandbox::SandboxBPFTestRunner bpf_test_runner(                    \
     92         new sandbox::BPFTesterCompatibilityDelegate<policy, aux>(     \
     93             BPF_TEST_##test_name));                                   \
     94     sandbox::UnitTests::RunTestInProcess(&bpf_test_runner, death);    \
     95   }                                                                   \
     96   void BPF_TEST_##test_name(aux* BPF_AUX)
     97 
     98 // This class takes a simple function pointer as a constructor parameter and a
     99 // class name as a template parameter to implement the BPFTesterDelegate
    100 // interface which can be used to build BPF unittests with
    101 // the SandboxBPFTestRunner class.
    102 template <class PolicyClass>
    103 class BPFTesterSimpleDelegate : public BPFTesterDelegate {
    104  public:
    105   explicit BPFTesterSimpleDelegate(void (*test_function)(void))
    106       : test_function_(test_function) {}
    107   ~BPFTesterSimpleDelegate() override {}
    108 
    109   std::unique_ptr<bpf_dsl::Policy> GetSandboxBPFPolicy() override {
    110     return std::unique_ptr<bpf_dsl::Policy>(new PolicyClass());
    111   }
    112   void RunTestFunction() override {
    113     DCHECK(test_function_);
    114     test_function_();
    115   }
    116 
    117  private:
    118   void (*test_function_)(void);
    119   DISALLOW_COPY_AND_ASSIGN(BPFTesterSimpleDelegate);
    120 };
    121 
    122 }  // namespace sandbox
    123 
    124 #endif  // SANDBOX_LINUX_SECCOMP_BPF_BPF_TESTS_H__
    125