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

security/sandbox/win/src/policy_low_level.h@6474c204b198 (annotated)

security/sandbox/win/src/policy_low_level.h

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 // 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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security/sandbox/win/src/policy_low_level.h@6474c204b198 (annotated)

security/sandbox/win/src/policy_low_level.h