gecko-dev/toolkit/xre/MacLaunchHelper.mm

/* -*- 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/. */

#include "MacLaunchHelper.h"

#include "MacAutoreleasePool.h"
#include "mozilla/UniquePtr.h"
#include "nsIAppStartup.h"
#include "nsMemory.h"

#include <Cocoa/Cocoa.h>
#include <crt_externs.h>
#include <ServiceManagement/ServiceManagement.h>
#include <Security/Authorization.h>
#include <spawn.h>
#include <stdio.h>

using namespace mozilla;

namespace {
cpu_type_t pref_cpu_types[2] = {
#if defined(__i386__)
                                 CPU_TYPE_X86,
#elif defined(__x86_64__)
                                 CPU_TYPE_X86_64,
#elif defined(__ppc__)
                                 CPU_TYPE_POWERPC,
#endif
                                 CPU_TYPE_ANY };

cpu_type_t cpu_i386_types[2] = {
                                 CPU_TYPE_X86,
                                 CPU_TYPE_ANY };

cpu_type_t cpu_x64_86_types[2] = {
                                 CPU_TYPE_X86_64,
                                 CPU_TYPE_ANY };
} // namespace

void LaunchChildMac(int aArgc, char** aArgv,
                    uint32_t aRestartType, pid_t *pid)
{
  // "posix_spawnp" uses null termination for arguments rather than a count.
  // Note that we are not duplicating the argument strings themselves.
  auto argv_copy = MakeUnique<char*[]>(aArgc + 1);
  for (int i = 0; i < aArgc; i++) {
    argv_copy[i] = aArgv[i];
  }
  argv_copy[aArgc] = NULL;

  // Initialize spawn attributes.
  posix_spawnattr_t spawnattr;
  if (posix_spawnattr_init(&spawnattr) != 0) {
    printf("Failed to init posix spawn attribute.");
    return;
  }

  cpu_type_t *wanted_type = pref_cpu_types;
  size_t attr_count = ArrayLength(pref_cpu_types);

  if (aRestartType & nsIAppStartup::eRestarti386) {
    wanted_type = cpu_i386_types;
    attr_count = ArrayLength(cpu_i386_types);
  } else if (aRestartType & nsIAppStartup::eRestartx86_64) {
    wanted_type = cpu_x64_86_types;
    attr_count = ArrayLength(cpu_x64_86_types);
  }

  // Set spawn attributes.
  size_t attr_ocount = 0;
  if (posix_spawnattr_setbinpref_np(&spawnattr, attr_count, wanted_type, &attr_ocount) != 0 ||
      attr_ocount != attr_count) {
    printf("Failed to set binary preference on posix spawn attribute.");
    posix_spawnattr_destroy(&spawnattr);
    return;
  }

  // Pass along our environment.
  char** envp = NULL;
  char*** cocoaEnvironment = _NSGetEnviron();
  if (cocoaEnvironment) {
    envp = *cocoaEnvironment;
  }

  int result = posix_spawnp(pid, argv_copy[0], NULL, &spawnattr, argv_copy.get(), envp);

  posix_spawnattr_destroy(&spawnattr);

  if (result != 0) {
    printf("Process spawn failed with code %d!", result);
  }
}

BOOL InstallPrivilegedHelper()
{
  AuthorizationRef authRef = NULL;
  OSStatus status = AuthorizationCreate(NULL,
                                        kAuthorizationEmptyEnvironment,
                                        kAuthorizationFlagDefaults |
                                        kAuthorizationFlagInteractionAllowed,
                                        &authRef);
  if (status != errAuthorizationSuccess) {
    // AuthorizationCreate really shouldn't fail.
    NSLog(@"AuthorizationCreate failed! NSOSStatusErrorDomain / %d",
          (int)status);
    return NO;
  }

  BOOL result = NO;
  AuthorizationItem authItem = { kSMRightBlessPrivilegedHelper, 0, NULL, 0 };
  AuthorizationRights authRights = { 1, &authItem };
  AuthorizationFlags flags = kAuthorizationFlagDefaults |
                             kAuthorizationFlagInteractionAllowed |
                             kAuthorizationFlagPreAuthorize |
                             kAuthorizationFlagExtendRights;

  // Obtain the right to install our privileged helper tool.
  status = AuthorizationCopyRights(authRef,
                                   &authRights,
                                   kAuthorizationEmptyEnvironment,
                                   flags,
                                   NULL);
  if (status != errAuthorizationSuccess) {
    NSLog(@"AuthorizationCopyRights failed! NSOSStatusErrorDomain / %d",
          (int)status);
  } else {
    CFErrorRef cfError;
    // This does all the work of verifying the helper tool against the
    // application and vice-versa. Once verification has passed, the embedded
    // launchd.plist is extracted and placed in /Library/LaunchDaemons and then
    // loaded. The executable is placed in /Library/PrivilegedHelperTools.
    result = (BOOL)SMJobBless(kSMDomainSystemLaunchd,
                              (CFStringRef)@"org.mozilla.updater",
                              authRef,
                              &cfError);
    if (!result) {
      NSLog(@"Unable to install helper!");
      CFRelease(cfError);
    }
  }

  return result;
}

void AbortElevatedUpdate()
{
  mozilla::MacAutoreleasePool pool;

  id updateServer = nil;
  int currTry = 0;
  const int numRetries = 10; // Number of IPC connection retries before
                             // giving up.
  while (currTry < numRetries) {
    @try {
      updateServer = (id)[NSConnection
        rootProxyForConnectionWithRegisteredName:
          @"org.mozilla.updater.server"
        host:nil
        usingNameServer:[NSSocketPortNameServer sharedInstance]];
      if (updateServer &&
          [updateServer respondsToSelector:@selector(abort)]) {
        [updateServer performSelector:@selector(abort)];
        return;
      }
      NSLog(@"Server doesn't exist or doesn't provide correct selectors.");
      sleep(1); // Wait 1 second.
      currTry++;
    } @catch (NSException* e) {
      NSLog(@"Encountered exception, retrying: %@: %@", e.name, e.reason);
      sleep(1); // Wait 1 second.
      currTry++;
    }
  }
  NSLog(@"Unable to clean up updater.");
}

bool LaunchElevatedUpdate(int argc, char** argv, uint32_t aRestartType,
                          pid_t* pid)
{
  LaunchChildMac(argc, argv, aRestartType, pid);
  bool didSucceed = InstallPrivilegedHelper();
  if (!didSucceed) {
    AbortElevatedUpdate();
  }
  return didSucceed;
}