/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

// The Mac sandbox module is a static library (a Library in moz.build terms)
// that can be linked into any binary (for example plugin-container or XUL).
// It must not have dependencies on any other Mozilla module.  This is why,
// for example, it has its own OS X version detection code, rather than
// linking to nsCocoaFeatures.mm in XUL.

#include "Sandbox.h"

#include <stdio.h>
#include <stdlib.h>
#include <CoreFoundation/CoreFoundation.h>

#include <iostream>
#include <sstream>
#include <vector>

#include "mozilla/Assertions.h"

// XXX There are currently problems with the /usr/include/sandbox.h file on
// some/all of the Macs in Mozilla's build system. Further,
// sandbox_init_with_parameters is not included in the header.  For the time
// being (until this problem is resolved), we refer directly to what we need
// from it, rather than including it here.
extern "C" int sandbox_init(const char *profile, uint64_t flags, char **errorbuf);
extern "C" int sandbox_init_with_parameters(const char *profile, uint64_t flags, const char *const parameters[], char **errorbuf);
extern "C" void sandbox_free_error(char *errorbuf);

#define MAC_OS_X_VERSION_10_0_HEX  0x00001000
#define MAC_OS_X_VERSION_10_6_HEX  0x00001060
#define MAC_OS_X_VERSION_10_7_HEX  0x00001070
#define MAC_OS_X_VERSION_10_8_HEX  0x00001080
#define MAC_OS_X_VERSION_10_9_HEX  0x00001090
#define MAC_OS_X_VERSION_10_10_HEX 0x000010A0

// Note about "major", "minor" and "bugfix" in the following code:
//
// The code decomposes an OS X version number into these components, and in
// doing so follows Apple's terminology in Gestalt.h.  But this is very
// misleading, because in other contexts Apple uses the "minor" component of
// an OS X version number to indicate a "major" release (for example the "9"
// in OS X 10.9.5), and the "bugfix" component to indicate a "minor" release
// (for example the "5" in OS X 10.9.5).

class OSXVersion {
public:
  static int32_t OSXVersionMinor();

private:
  static void GetSystemVersion(int32_t& aMajor, int32_t& aMinor, int32_t& aBugFix);
  static int32_t GetVersionNumber();
  static int32_t mOSXVersion;
};

int32_t OSXVersion::mOSXVersion = -1;

int32_t OSXVersion::OSXVersionMinor()
{
  return (GetVersionNumber() & 0xF0) >> 4;
}

void
OSXVersion::GetSystemVersion(int32_t& aMajor, int32_t& aMinor, int32_t& aBugFix)
{
  SInt32 major = 0, minor = 0, bugfix = 0;

  CFURLRef url =
    CFURLCreateWithString(kCFAllocatorDefault,
                          CFSTR("file:///System/Library/CoreServices/SystemVersion.plist"),
                          NULL);
  CFReadStreamRef stream =
    CFReadStreamCreateWithFile(kCFAllocatorDefault, url);
  CFReadStreamOpen(stream);
  CFDictionaryRef sysVersionPlist = (CFDictionaryRef)
    CFPropertyListCreateWithStream(kCFAllocatorDefault,
                                   stream, 0, kCFPropertyListImmutable,
                                   NULL, NULL);
  CFReadStreamClose(stream);
  CFRelease(stream);
  CFRelease(url);

  CFStringRef versionString = (CFStringRef)
    CFDictionaryGetValue(sysVersionPlist, CFSTR("ProductVersion"));
  CFArrayRef versions =
    CFStringCreateArrayBySeparatingStrings(kCFAllocatorDefault,
                                           versionString, CFSTR("."));
  CFIndex count = CFArrayGetCount(versions);
  if (count > 0) {
    CFStringRef component = (CFStringRef) CFArrayGetValueAtIndex(versions, 0);
    major = CFStringGetIntValue(component);
    if (count > 1) {
      component = (CFStringRef) CFArrayGetValueAtIndex(versions, 1);
      minor = CFStringGetIntValue(component);
      if (count > 2) {
        component = (CFStringRef) CFArrayGetValueAtIndex(versions, 2);
        bugfix = CFStringGetIntValue(component);
      }
    }
  }
  CFRelease(sysVersionPlist);
  CFRelease(versions);

  // If 'major' isn't what we expect, assume the oldest version of OS X we
  // currently support (OS X 10.6).
  if (major != 10) {
    aMajor = 10; aMinor = 6; aBugFix = 0;
  } else {
    aMajor = major; aMinor = minor; aBugFix = bugfix;
  }
}

int32_t
OSXVersion::GetVersionNumber()
{
  if (mOSXVersion == -1) {
    int32_t major, minor, bugfix;
    GetSystemVersion(major, minor, bugfix);
    mOSXVersion = MAC_OS_X_VERSION_10_0_HEX + (minor << 4) + bugfix;
  }
  return mOSXVersion;
}

bool
GetRealPath(std::string& aOutputPath, const char* aInputPath)
{
  char* resolvedPath = realpath(aInputPath, nullptr);
  if (resolvedPath == nullptr) {
    return false;
  }

  aOutputPath = resolvedPath;
  free(resolvedPath);

  return !aOutputPath.empty();
}

namespace mozilla {

bool StartMacSandbox(MacSandboxInfo const &aInfo, std::string &aErrorMessage)
{
  std::vector<const char *> params;
  std::string profile;
  std::string macOSMinor = std::to_string(OSXVersion::OSXVersionMinor());

  // Used for the Flash sandbox. Declared here so that they
  // stay in scope until sandbox_init_with_parameters is called.
  std::string flashCacheDir, flashTempDir, flashPath;

  if (aInfo.type == MacSandboxType_Plugin &&
      aInfo.pluginInfo.type == MacSandboxPluginType_Flash) {
    profile = flashPluginSandboxRules;

    params.push_back("SHOULD_LOG");
    params.push_back(aInfo.shouldLog ? "TRUE" : "FALSE");

    params.push_back("SANDBOX_LEVEL_1");
    params.push_back(aInfo.level == 1 ? "TRUE" : "FALSE");
    params.push_back("SANDBOX_LEVEL_2");
    params.push_back(aInfo.level == 2 ? "TRUE" : "FALSE");

    params.push_back("MAC_OS_MINOR");
    params.push_back(macOSMinor.c_str());

    params.push_back("HOME_PATH");
    params.push_back(getenv("HOME"));

    params.push_back("PLUGIN_BINARY_PATH");
    if (!GetRealPath(flashPath, aInfo.pluginInfo.pluginBinaryPath.c_str())) {
      return false;
    }
    params.push_back(flashPath.c_str());

    // User cache dir
    params.push_back("DARWIN_USER_CACHE_DIR");
    char confStrBuf[PATH_MAX];
    if (!confstr(_CS_DARWIN_USER_CACHE_DIR, confStrBuf, sizeof(confStrBuf))) {
      return false;
    }
    if (!GetRealPath(flashCacheDir, confStrBuf)) {
      return false;
    }
    params.push_back(flashCacheDir.c_str());

    // User temp dir
    params.push_back("DARWIN_USER_TEMP_DIR");
    if (!confstr(_CS_DARWIN_USER_TEMP_DIR, confStrBuf, sizeof(confStrBuf))) {
      return false;
    }
    if (!GetRealPath(flashTempDir, confStrBuf)) {
      return false;
    }
    params.push_back(flashTempDir.c_str());
  }
  else if (aInfo.type == MacSandboxType_Plugin) {
    profile = const_cast<char *>(pluginSandboxRules);
    params.push_back("SHOULD_LOG");
    params.push_back(aInfo.shouldLog ? "TRUE" : "FALSE");
    params.push_back("PLUGIN_BINARY_PATH");
    params.push_back(aInfo.pluginInfo.pluginBinaryPath.c_str());
    params.push_back("APP_PATH");
    params.push_back(aInfo.appPath.c_str());
    params.push_back("APP_BINARY_PATH");
    params.push_back(aInfo.appBinaryPath.c_str());

    if (aInfo.pluginInfo.type == MacSandboxPluginType_GMPlugin_EME_Widevine) {
      profile.append(widevinePluginSandboxRulesAddend);
    }
  }
  else if (aInfo.type == MacSandboxType_Content) {
    MOZ_ASSERT(aInfo.level >= 1);
    if (aInfo.level >= 1) {
      profile = contentSandboxRules;
      params.push_back("SHOULD_LOG");
      params.push_back(aInfo.shouldLog ? "TRUE" : "FALSE");
      params.push_back("SANDBOX_LEVEL_1");
      params.push_back(aInfo.level == 1 ? "TRUE" : "FALSE");
      params.push_back("SANDBOX_LEVEL_2");
      params.push_back(aInfo.level == 2 ? "TRUE" : "FALSE");
      params.push_back("SANDBOX_LEVEL_3");
      params.push_back(aInfo.level == 3 ? "TRUE" : "FALSE");
      params.push_back("MAC_OS_MINOR");
      params.push_back(macOSMinor.c_str());
      params.push_back("APP_PATH");
      params.push_back(aInfo.appPath.c_str());
      params.push_back("PROFILE_DIR");
      params.push_back(aInfo.profileDir.c_str());
      params.push_back("HOME_PATH");
      params.push_back(getenv("HOME"));
      params.push_back("HAS_SANDBOXED_PROFILE");
      params.push_back(aInfo.hasSandboxedProfile ? "TRUE" : "FALSE");
      params.push_back("HAS_WINDOW_SERVER");
      params.push_back(aInfo.hasWindowServer ? "TRUE" : "FALSE");
      if (!aInfo.crashServerPort.empty()) {
        params.push_back("CRASH_PORT");
        params.push_back(aInfo.crashServerPort.c_str());
      }
      if (!aInfo.testingReadPath1.empty()) {
        params.push_back("TESTING_READ_PATH1");
        params.push_back(aInfo.testingReadPath1.c_str());
      }
      if (!aInfo.testingReadPath2.empty()) {
        params.push_back("TESTING_READ_PATH2");
        params.push_back(aInfo.testingReadPath2.c_str());
      }
      if (!aInfo.testingReadPath3.empty()) {
        params.push_back("TESTING_READ_PATH3");
        params.push_back(aInfo.testingReadPath3.c_str());
      }
      if (!aInfo.testingReadPath4.empty()) {
        params.push_back("TESTING_READ_PATH4");
        params.push_back(aInfo.testingReadPath4.c_str());
      }
#ifdef DEBUG
      if (!aInfo.debugWriteDir.empty()) {
        params.push_back("DEBUG_WRITE_DIR");
        params.push_back(aInfo.debugWriteDir.c_str());
      }
#endif // DEBUG

      if (aInfo.hasFilePrivileges) {
        profile.append(fileContentProcessAddend);
      }
      if (aInfo.hasAudio) {
        profile.append(contentProcessAudioAddend);
      }
    } else {
      fprintf(stderr,
        "Content sandbox disabled due to sandbox level setting\n");
      return false;
    }
  }
  else {
    char *msg = NULL;
    asprintf(&msg, "Unexpected sandbox type %u", aInfo.type);
    if (msg) {
      aErrorMessage.assign(msg);
      free(msg);
    }
    return false;
  }

  if (profile.empty()) {
    fprintf(stderr, "Out of memory in StartMacSandbox()!\n");
    return false;
  }

// In order to avoid relying on any other Mozilla modules (as described at the
// top of this file), we use our own #define instead of the existing MOZ_LOG
// infrastructure. This can be used by developers to debug the macOS sandbox
// policy.
#define MAC_SANDBOX_PRINT_POLICY 0
#if MAC_SANDBOX_PRINT_POLICY
  printf("Sandbox params:\n");
  for (size_t i = 0; i < params.size() / 2; i++) {
    printf("  %s = %s\n", params[i * 2], params[(i * 2) + 1]);
  }
  printf("Sandbox profile:\n%s\n", profile.c_str());
#endif

  // The parameters array is null terminated.
  params.push_back(nullptr);

  char *errorbuf = NULL;
  int rv = sandbox_init_with_parameters(profile.c_str(), 0, params.data(),
                                        &errorbuf);
  if (rv) {
    if (errorbuf) {
      char *msg = NULL;
      asprintf(&msg, "sandbox_init() failed with error \"%s\"", errorbuf);
      if (msg) {
        aErrorMessage.assign(msg);
        free(msg);
      }
      fprintf(stderr, "profile: %s\n", profile.c_str());
      sandbox_free_error(errorbuf);
    }
  }
  if (rv) {
    return false;
  }

  return true;
}

/*
 * Fill |aInfo| with content sandbox params parsed from the provided
 * command line arguments. Return false if any sandbox parameters needed
 * for early startup of the sandbox are not present in the arguments.
 */
bool
GetContentSandboxParamsFromArgs(int aArgc, char** aArgv, MacSandboxInfo& aInfo)
{
  // Ensure we find these paramaters in the command
  // line arguments. Return false if any are missing.
  bool foundSandboxLevel = false;
  bool foundValidSandboxLevel = false;
  bool foundAppPath = false;

  // Read access directories used in testing
  int nTestingReadPaths = 0;
  std::string testingReadPaths[MAX_TESTING_READ_PATHS] = {};

  // Collect sandbox params from CLI arguments
  for (int i = 0; i < aArgc; i++) {

    if ((strcmp(aArgv[i], "-sbLevel") == 0) && (i + 1 < aArgc)) {
      std::stringstream ss(aArgv[i+1]);
      int level = 0;
      ss >> level;
      foundSandboxLevel = true;
      aInfo.level = level;
      foundValidSandboxLevel = level > 0 && level <= 3 ? true : false;
      if (!foundValidSandboxLevel) {
        break;
      }
      i++;
      continue;
    }

    if (strcmp(aArgv[i], "-sbLogging") == 0) {
      aInfo.shouldLog = true;
      continue;
    }

    if (strcmp(aArgv[i], "-sbAllowFileAccess") == 0) {
      aInfo.hasFilePrivileges = true;
      continue;
    }

    if (strcmp(aArgv[i], "-sbAllowAudio") == 0) {
      aInfo.hasAudio = true;
      continue;
    }

    if (strcmp(aArgv[i], "-sbAllowWindowServer") == 0) {
      aInfo.hasWindowServer = true;
      continue;
    }

    if ((strcmp(aArgv[i], "-sbAppPath") == 0) && (i + 1 < aArgc)) {
      foundAppPath = true;
      aInfo.appPath.assign(aArgv[i+1]);
      i++;
      continue;
    }

    if ((strcmp(aArgv[i], "-sbTestingReadPath") == 0) && (i + 1 < aArgc)) {
      MOZ_ASSERT(nTestingReadPaths < MAX_TESTING_READ_PATHS);
      testingReadPaths[nTestingReadPaths] = aArgv[i+1];
      nTestingReadPaths++;
      i++;
      continue;
    }

    if ((strcmp(aArgv[i], "-profile") == 0) && (i + 1 < aArgc)) {
      aInfo.hasSandboxedProfile = true;
      aInfo.profileDir.assign(aArgv[i+1]);
      i++;
      continue;
    }

#ifdef DEBUG
    if ((strcmp(aArgv[i], "-sbDebugWriteDir") == 0) && (i + 1 < aArgc)) {
      aInfo.debugWriteDir.assign(aArgv[i+1]);
      i++;
      continue;
    }
#endif // DEBUG

    // Handle crash server positional argument
    if (strstr(aArgv[i], "gecko-crash-server-pipe") != NULL) {
      aInfo.crashServerPort.assign(aArgv[i]);
      continue;
    }
  }

  if (!foundSandboxLevel) {
    fprintf(stderr, "Content sandbox disabled due to "
                    "missing sandbox CLI level parameter.\n");
    return false;
  }

  if (!foundValidSandboxLevel) {
    fprintf(stderr, "Content sandbox disabled due to invalid"
                    "sandbox level (%d)\n", aInfo.level);
    return false;
  }

  if (!foundAppPath) {
    fprintf(stderr, "Content sandbox disabled due to "
                    "missing sandbox CLI app path parameter.\n");
    return false;
  }

  aInfo.testingReadPath1 = testingReadPaths[0];
  aInfo.testingReadPath2 = testingReadPaths[1];
  aInfo.testingReadPath3 = testingReadPaths[2];
  aInfo.testingReadPath4 = testingReadPaths[3];

  return true;
}

/*
 * Returns true if no errors were encountered or if early sandbox startup is
 * not enabled for this process. Returns false if an error was encountered.
 */
bool
EarlyStartMacSandboxIfEnabled(int aArgc, char** aArgv,
                              std::string &aErrorMessage)
{
  bool earlyStartupEnabled = false;

  // Check for the -sbStartup CLI parameter which
  // indicates we should start the sandbox now.
  for (int i = 0; i < aArgc; i++) {
    if (strcmp(aArgv[i], "-sbStartup") == 0) {
      earlyStartupEnabled = true;
      break;
    }
  }

  // The sandbox will be started later when/if parent
  // sends the sandbox startup message. Return true
  // indicating no errors occurred.
  if (!earlyStartupEnabled) {
    return true;
  }

  MacSandboxInfo info;
  info.type = MacSandboxType_Content;
  if (!GetContentSandboxParamsFromArgs(aArgc, aArgv, info)) {
    return false;
  }

  return StartMacSandbox(info, aErrorMessage);
}

#ifdef DEBUG
/*
 * Ensures that a process sandbox is enabled by attempting to enable
 * a new sandbox policy and ASSERT'ing that this fails. This depends
 * on sandbox_init() failing when called again after a sandbox has
 * already been successfully enabled.
 */
void
AssertMacSandboxEnabled()
{
  char *errorbuf = NULL;
  int rv = sandbox_init("(version 1)(deny default)", 0, &errorbuf);
  MOZ_ASSERT(rv != 0);
}
#endif /* DEBUG */

} // namespace mozilla