The Tor Browser: comparison security/sandbox/win/src/policy_low

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+:19cb279450db
+// Copyright (c) 2006-2008 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_SRC_POLICY_LOW_LEVEL_H__
+#define SANDBOX_SRC_POLICY_LOW_LEVEL_H__
+#include <list>
+#include "base/basictypes.h"
+#include "sandbox/win/src/ipc_tags.h"
+#include "sandbox/win/src/policy_engine_params.h"
+#include "sandbox/win/src/policy_engine_opcodes.h"
+// Low level policy classes.
+// Built on top of the PolicyOpcode and OpcodeFatory, the low level policy
+// provides a way to define rules on strings and numbers but it is unaware
+// of Windows specific details or how the Interceptions must be set up.
+// To use these classes you construct one or more rules and add them to the
+// LowLevelPolicy object like this:
+//
+//   PolicyRule rule1(ASK_BROKER);
+//   rule1.AddStringMatch(IF, 0, L"\\\\/?/?\\c:\\*Microsoft*\\*.exe", true);
+//   rule1.AddNumberMatch(IF_NOT, 1, CREATE_ALWAYS, EQUAL);
+//   rule1.AddNumberMatch(IF, 2, FILE_ATTRIBUTE_NORMAL, EQUAL);
+//
+//   PolicyRule rule2(FAKE_SUCCESS);
+//   rule2.AddStringMatch(IF, 0, L"\\\\/?/?\\Pipe\\Chrome.*", false));
+//   rule2.AddNumberMatch(IF, 1, OPEN_EXISTING, EQUAL));
+//
+//   LowLevelPolicy policyGen(*policy_memory);
+//   policyGen.AddRule(kNtCreateFileSvc, &rule1);
+//   policyGen.AddRule(kNtCreateFileSvc, &rule2);
+//   policyGen.Done();
+//
+// At this point (error checking omitted) the policy_memory can be copied
+// to the target process where it can be evaluated.
+namespace sandbox {
+// TODO(cpu): Move this constant to crosscall_client.h.
+const size_t kMaxServiceCount = 32;
+COMPILE_ASSERT(IPC_LAST_TAG <= kMaxServiceCount, kMaxServiceCount_is_too_low);
+// Defines the memory layout of the policy. This memory is filled by
+// LowLevelPolicy object.
+// For example:
+//
+//  [Service 0] --points to---\
+//  [Service 1] --------------|-----\
+//   ......                   |     |
+//  [Service N]               |     |
+//  [data_size]               |     |
+//  [Policy Buffer 0] <-------/     |
+//  [opcodes of]                    |
+//  .......                         |
+//  [Policy Buffer 1] <-------------/
+//  [opcodes]
+//  .......
+//  .......
+//  [Policy Buffer N]
+//  [opcodes]
+//  .......
+//   <possibly unused space here>
+//  .......
+//  [opcode string ]
+//  [opcode string ]
+//  .......
+//  [opcode string ]
+struct PolicyGlobal {
+PolicyBuffer* entry[kMaxServiceCount];
+size_t data_size;
+PolicyBuffer data[1];
+};
+class PolicyRule;
+// Provides the means to collect rules into a policy store (memory)
+class LowLevelPolicy {
+public:
+// policy_store: must contain allocated memory and the internal
+// size fields set to correct values.
+explicit LowLevelPolicy(PolicyGlobal* policy_store)
+: policy_store_(policy_store) {
+}
+// Destroys all the policy rules.
+~LowLevelPolicy();
+// Adds a rule to be generated when Done() is called.
+// service: The id of the service that this rule is associated with,
+// for example the 'Open Thread' service or the "Create File" service.
+// returns false on error.
+bool AddRule(int service, PolicyRule* rule);
+// Generates all the rules added with AddRule() into the memory area
+// passed on the constructor. Returns false on error.
+bool Done();
+private:
+struct RuleNode {
+const PolicyRule* rule;
+int service;
+};
+std::list<RuleNode> rules_;
+PolicyGlobal* policy_store_;
+DISALLOW_IMPLICIT_CONSTRUCTORS(LowLevelPolicy);
+};
+// There are 'if' rules and 'if not' comparisons
+enum RuleType {
+IF = 0,
+IF_NOT = 1,
+};
+// Possible comparisons for numbers
+enum RuleOp {
+EQUAL,
+AND,
+RANGE   // TODO(cpu): Implement this option.
+};
+// Provides the means to collect a set of comparisons into a single
+// rule and its associated action.
+class PolicyRule {
+friend class LowLevelPolicy;
+public:
+explicit PolicyRule(EvalResult action);
+PolicyRule(const PolicyRule& other);
+~PolicyRule();
+// Adds a string comparison to the rule.
+// rule_type: possible values are IF and IF_NOT.
+// parameter: the expected index of the argument for this rule. For example
+// in a 'create file' service the file name argument can be at index 0.
+// string: is the desired matching pattern.
+// match_opts: if the pattern matching is case sensitive or not.
+bool AddStringMatch(RuleType rule_type, int16 parameter,
+const wchar_t* string, StringMatchOptions match_opts);
+// Adds a number match comparison to the rule.
+// rule_type: possible values are IF and IF_NOT.
+// parameter: the expected index of the argument for this rule.
+// number: the value to compare the input to.
+// comparison_op: the comparison kind (equal, logical and, etc).
+bool AddNumberMatch(RuleType rule_type, int16 parameter,
+unsigned long number, RuleOp comparison_op);
+// Returns the number of opcodes generated so far.
+size_t GetOpcodeCount() const {
+return buffer_->opcode_count;
+}
+// Called when there is no more comparisons to add. Internally it generates
+// the last opcode (the action opcode). Returns false if this operation fails.
+bool Done();
+private:
+void operator=(const PolicyRule&);
+// Called in a loop from AddStringMatch to generate the required string
+// match opcodes. rule_type, match_opts and parameter are the same as
+// in AddStringMatch.
+bool GenStringOpcode(RuleType rule_type, StringMatchOptions match_opts,
+uint16 parameter, int state, bool last_call,
+int* skip_count, std::wstring* fragment);
+// Loop over all generated opcodes and copy them to increasing memory
+// addresses from opcode_start and copy the extra data (strings usually) into
+// decreasing addresses from data_start. Extra data is only present in the
+// string evaluation opcodes.
+bool RebindCopy(PolicyOpcode* opcode_start, size_t opcode_size,
+char* data_start, size_t* data_size) const;
+PolicyBuffer* buffer_;
+OpcodeFactory* opcode_factory_;
+EvalResult action_;
+bool done_;
+};
+}  // namespace sandbox
+#endif  // SANDBOX_SRC_POLICY_LOW_LEVEL_H__

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comparison: security/sandbox/win/src/policy_low_level.h

security/sandbox/win/src/policy_low_level.h