authorization_util.h revision c407dc5cd9bdc5668497f21b26b09d988ab439de 
1// Copyright (c) 2009 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef CHROME_BROWSER_COCOA_AUTHORIZATION_UTIL_H_
6#define CHROME_BROWSER_COCOA_AUTHORIZATION_UTIL_H_
7
8// AuthorizationExecuteWithPrivileges fork()s and exec()s the tool, but it
9// does not wait() for it.  It also doesn't provide the caller with access to
10// the forked pid.  If used irresponsibly, zombie processes will accumulate.
11//
12// Apple's really gotten us between a rock and a hard place, here.
13//
14// Fortunately, AuthorizationExecuteWithPrivileges does give access to the
15// tool's stdout (and stdin) via a FILE* pipe.  The tool can output its pid
16// to this pipe, and the main program can read it, and then have something
17// that it can wait() for.
18//
19// The contract is that any tool executed by the wrappers declared in this
20// file must print its pid to stdout on a line by itself before doing anything
21// else.
22//
23// http://developer.apple.com/mac/library/samplecode/BetterAuthorizationSample/listing1.html
24// (Look for "What's This About Zombies?")
25
26#include <CoreFoundation/CoreFoundation.h>
27#include <Security/Authorization.h>
28#include <stdio.h>
29#include <sys/types.h>
30
31namespace authorization_util {
32
33// Obtains an AuthorizationRef that can be used to run commands as root.  If
34// necessary, prompts the user for authentication.  If the user is prompted,
35// |prompt| will be used as the prompt string and an icon appropriate for the
36// application will be displayed in a prompt dialog.  Note that the system
37// appends its own text to the prompt string.  Returns NULL on failure.
38AuthorizationRef AuthorizationCreateToRunAsRoot(CFStringRef prompt);
39
40// Calls straight through to AuthorizationExecuteWithPrivileges.  If that
41// call succeeds, |pid| will be set to the pid of the executed tool.  If the
42// pid can't be determined, |pid| will be set to -1.  |pid| must not be NULL.
43// |pipe| may be NULL, but the tool will always be executed with a pipe in
44// order to read the pid from its stdout.
45OSStatus ExecuteWithPrivilegesAndGetPID(AuthorizationRef authorization,
46                                        const char* tool_path,
47                                        AuthorizationFlags options,
48                                        const char** arguments,
49                                        FILE** pipe,
50                                        pid_t* pid);
51
52// Calls ExecuteWithPrivilegesAndGetPID, and if that call succeeds, calls
53// waitpid() to wait for the process to exit.  If waitpid() succeeds, the
54// exit status is placed in |exit_status|, otherwise, -1 is stored.
55// |exit_status| may be NULL and this function will still wait for the process
56// to exit.
57OSStatus ExecuteWithPrivilegesAndWait(AuthorizationRef authorization,
58                                      const char* tool_path,
59                                      AuthorizationFlags options,
60                                      const char** arguments,
61                                      FILE** pipe,
62                                      int* exit_status);
63
64}  // namespace authorization_util
65
66#endif  // CHROME_BROWSER_COCOA_AUTHORIZATION_UTIL_H_
67