Index: sandbox/linux/seccomp-bpf/errorcode.h |
diff --git a/sandbox/linux/seccomp-bpf/errorcode.h b/sandbox/linux/seccomp-bpf/errorcode.h |
deleted file mode 100644 |
index d88777313e3ef10abe6bc5b55689f097810ffdcf..0000000000000000000000000000000000000000 |
--- a/sandbox/linux/seccomp-bpf/errorcode.h |
+++ /dev/null |
@@ -1,203 +0,0 @@ |
-// Copyright (c) 2012 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_SECCOMP_BPF_ERRORCODE_H__ |
-#define SANDBOX_LINUX_SECCOMP_BPF_ERRORCODE_H__ |
- |
-#include "sandbox/linux/seccomp-bpf/trap.h" |
-#include "sandbox/sandbox_export.h" |
- |
-namespace sandbox { |
-namespace bpf_dsl { |
-class PolicyCompiler; |
-} |
- |
-// This class holds all the possible values that can be returned by a sandbox |
-// policy. |
-// We can either wrap a symbolic ErrorCode (i.e. ERR_XXX enum values), an |
-// errno value (in the range 0..4095), a pointer to a TrapFnc callback |
-// handling a SECCOMP_RET_TRAP trap, or a complex constraint. |
-// All of the commonly used values are stored in the "err_" field. So, code |
-// that is using the ErrorCode class typically operates on a single 32bit |
-// field. |
-// |
-// TODO(mdempsky): Nuke from orbit. The only reason this class still |
-// exists is for Verifier, which will eventually be replaced by a true |
-// BPF symbolic evaluator and constraint solver. |
-class SANDBOX_EXPORT ErrorCode { |
- public: |
- enum { |
- // Allow this system call. The value of ERR_ALLOWED is pretty much |
- // completely arbitrary. But we want to pick it so that is is unlikely |
- // to be passed in accidentally, when the user intended to return an |
- // "errno" (see below) value instead. |
- ERR_ALLOWED = 0x04000000, |
- |
- // If the progress is being ptraced with PTRACE_O_TRACESECCOMP, then the |
- // tracer will be notified of a PTRACE_EVENT_SECCOMP and allowed to change |
- // or skip the system call. The lower 16 bits of err will be available to |
- // the tracer via PTRACE_GETEVENTMSG. |
- ERR_TRACE = 0x08000000, |
- |
- // Deny the system call with a particular "errno" value. |
- // N.B.: It is also possible to return "0" here. That would normally |
- // indicate success, but it won't actually run the system call. |
- // This is very different from return ERR_ALLOWED. |
- ERR_MIN_ERRNO = 0, |
-#if defined(__mips__) |
- // MIPS only supports errno up to 1133 |
- ERR_MAX_ERRNO = 1133, |
-#else |
- // TODO(markus): Android only supports errno up to 255 |
- // (crbug.com/181647). |
- ERR_MAX_ERRNO = 4095, |
-#endif |
- }; |
- |
- // While BPF filter programs always operate on 32bit quantities, the kernel |
- // always sees system call arguments as 64bit values. This statement is true |
- // no matter whether the host system is natively operating in 32bit or 64bit. |
- // The BPF compiler hides the fact that BPF instructions cannot directly |
- // access 64bit quantities. But policies are still advised to specify whether |
- // a system call expects a 32bit or a 64bit quantity. |
- enum ArgType { |
- // When passed as an argument to SandboxBPF::Cond(), TP_32BIT requests that |
- // the conditional test should operate on the 32bit part of the system call |
- // argument. |
- // On 64bit architectures, this verifies that user space did not pass |
- // a 64bit value as an argument to the system call. If it did, that will be |
- // interpreted as an attempt at breaking the sandbox and results in the |
- // program getting terminated. |
- // In other words, only perform a 32bit test, if you are sure this |
- // particular system call would never legitimately take a 64bit |
- // argument. |
- // Implementation detail: TP_32BIT does two things. 1) it restricts the |
- // conditional test to operating on the LSB only, and 2) it adds code to |
- // the BPF filter program verifying that the MSB the kernel received from |
- // user space is either 0, or 0xFFFFFFFF; the latter is acceptable, iff bit |
- // 31 was set in the system call argument. It deals with 32bit arguments |
- // having been sign extended. |
- TP_32BIT, |
- |
- // When passed as an argument to SandboxBPF::Cond(), TP_64BIT requests that |
- // the conditional test should operate on the full 64bit argument. It is |
- // generally harmless to perform a 64bit test on 32bit systems, as the |
- // kernel will always see the top 32 bits of all arguments as zero'd out. |
- // This approach has the desirable property that for tests of pointer |
- // values, we can always use TP_64BIT no matter the host architecture. |
- // But of course, that also means, it is possible to write conditional |
- // policies that turn into no-ops on 32bit systems; this is by design. |
- TP_64BIT, |
- }; |
- |
- // Deprecated. |
- enum Operation { |
- // Test whether the system call argument is equal to the operand. |
- OP_EQUAL, |
- |
- // Tests a system call argument against a bit mask. |
- // The "ALL_BITS" variant performs this test: "arg & mask == mask" |
- // This implies that a mask of zero always results in a passing test. |
- // The "ANY_BITS" variant performs this test: "arg & mask != 0" |
- // This implies that a mask of zero always results in a failing test. |
- OP_HAS_ALL_BITS, |
- OP_HAS_ANY_BITS, |
- }; |
- |
- enum ErrorType { |
- ET_INVALID, |
- ET_SIMPLE, |
- ET_TRAP, |
- ET_COND, |
- }; |
- |
- // We allow the default constructor, as it makes the ErrorCode class |
- // much easier to use. But if we ever encounter an invalid ErrorCode |
- // when compiling a BPF filter, we deliberately generate an invalid |
- // program that will get flagged both by our Verifier class and by |
- // the Linux kernel. |
- ErrorCode(); |
- explicit ErrorCode(int err); |
- |
- // For all practical purposes, ErrorCodes are treated as if they were |
- // structs. The copy constructor and assignment operator are trivial and |
- // we do not need to explicitly specify them. |
- // Most notably, it is in fact perfectly OK to directly copy the passed_ and |
- // failed_ field. They only ever get set by our private constructor, and the |
- // callers handle life-cycle management for these objects. |
- |
- // Destructor |
- ~ErrorCode() {} |
- |
- bool Equals(const ErrorCode& err) const; |
- bool LessThan(const ErrorCode& err) const; |
- |
- uint32_t err() const { return err_; } |
- ErrorType error_type() const { return error_type_; } |
- |
- bool safe() const { return safe_; } |
- |
- uint64_t mask() const { return mask_; } |
- uint64_t value() const { return value_; } |
- int argno() const { return argno_; } |
- ArgType width() const { return width_; } |
- const ErrorCode* passed() const { return passed_; } |
- const ErrorCode* failed() const { return failed_; } |
- |
- struct LessThan { |
- bool operator()(const ErrorCode& a, const ErrorCode& b) const { |
- return a.LessThan(b); |
- } |
- }; |
- |
- private: |
- friend bpf_dsl::PolicyCompiler; |
- friend class CodeGen; |
- friend class SandboxBPF; |
- friend class Trap; |
- |
- // If we are wrapping a callback, we must assign a unique id. This id is |
- // how the kernel tells us which one of our different SECCOMP_RET_TRAP |
- // cases has been triggered. |
- ErrorCode(uint16_t trap_id, Trap::TrapFnc fnc, const void* aux, bool safe); |
- |
- // Some system calls require inspection of arguments. This constructor |
- // allows us to specify additional constraints. |
- ErrorCode(int argno, |
- ArgType width, |
- uint64_t mask, |
- uint64_t value, |
- const ErrorCode* passed, |
- const ErrorCode* failed); |
- |
- ErrorType error_type_; |
- |
- union { |
- // Fields needed for SECCOMP_RET_TRAP callbacks |
- struct { |
- Trap::TrapFnc fnc_; // Callback function and arg, if trap was |
- void* aux_; // triggered by the kernel's BPF filter. |
- bool safe_; // Keep sandbox active while calling fnc_() |
- }; |
- |
- // Fields needed when inspecting additional arguments. |
- struct { |
- uint64_t mask_; // Mask that we are comparing under. |
- uint64_t value_; // Value that we are comparing with. |
- int argno_; // Syscall arg number that we are inspecting. |
- ArgType width_; // Whether we are looking at a 32/64bit value. |
- const ErrorCode* passed_; // Value to be returned if comparison passed, |
- const ErrorCode* failed_; // or if it failed. |
- }; |
- }; |
- |
- // 32bit field used for all possible types of ErrorCode values. This is |
- // the value that uniquely identifies any ErrorCode and it (typically) can |
- // be emitted directly into a BPF filter program. |
- uint32_t err_; |
-}; |
- |
-} // namespace sandbox |
- |
-#endif // SANDBOX_LINUX_SECCOMP_BPF_ERRORCODE_H__ |