Index: sandbox/linux/bpf_dsl/trap_registry.h |
diff --git a/sandbox/linux/bpf_dsl/trap_registry.h b/sandbox/linux/bpf_dsl/trap_registry.h |
new file mode 100644 |
index 0000000000000000000000000000000000000000..94d4722c8cc359dce0574f0982279b0d1e5d58db |
--- /dev/null |
+++ b/sandbox/linux/bpf_dsl/trap_registry.h |
@@ -0,0 +1,64 @@ |
+// Copyright 2014 The Chromium Authors. All rights reserved. |
+// Use of this source code is governed by a BSD-style license that can be |
+// found in the LICENSE file. |
+ |
+#ifndef SANDBOX_LINUX_BPF_DSL_TRAP_REGISTRY_H_ |
+#define SANDBOX_LINUX_BPF_DSL_TRAP_REGISTRY_H_ |
+ |
+#include <stdint.h> |
+ |
+#include "base/macros.h" |
+#include "sandbox/sandbox_export.h" |
+ |
+namespace sandbox { |
+ |
+// This must match the kernel's seccomp_data structure. |
+struct arch_seccomp_data { |
+ int nr; |
+ uint32_t arch; |
+ uint64_t instruction_pointer; |
+ uint64_t args[6]; |
+}; |
+ |
+namespace bpf_dsl { |
+ |
+// TrapRegistry provides an interface for registering "trap handlers" |
+// by associating them with non-zero 16-bit trap IDs. Trap IDs should |
+// remain valid for the lifetime of the trap registry. |
+class SANDBOX_EXPORT TrapRegistry { |
+ public: |
+ // TrapFnc is a pointer to a function that fulfills the trap handler |
+ // function signature. |
+ // |
+ // Trap handlers follow the calling convention of native system |
+ // calls; e.g., to report an error, they return an exit code in the |
+ // range -1..-4096 instead of directly modifying errno. However, |
+ // modifying errno is harmless, as the original value will be |
+ // restored afterwards. |
+ // |
+ // Trap handlers are executed from signal context and possibly an |
+ // async-signal context, so they must be async-signal safe: |
+ // http://pubs.opengroup.org/onlinepubs/009695399/functions/xsh_chap02_04.html |
+ typedef intptr_t (*TrapFnc)(const struct arch_seccomp_data& args, void* aux); |
+ |
+ // Add registers the specified trap handler tuple and returns a |
+ // non-zero trap ID that uniquely identifies the tuple for the life |
+ // time of the trap registry. If the same tuple is registered |
+ // multiple times, the same value will be returned each time. |
+ virtual uint16_t Add(TrapFnc fnc, const void* aux, bool safe) = 0; |
+ |
+ // EnableUnsafeTraps tries to enable unsafe traps and returns |
+ // whether it was successful. This is a one-way operation. |
+ virtual bool EnableUnsafeTraps() = 0; |
+ |
+ protected: |
+ TrapRegistry() {} |
+ ~TrapRegistry() {} |
+ |
+ DISALLOW_COPY_AND_ASSIGN(TrapRegistry); |
+}; |
+ |
+} // namespace bpf_dsl |
+} // namespace sandbox |
+ |
+#endif // SANDBOX_LINUX_BPF_DSL_TRAP_REGISTRY_H_ |