]>
Commit | Line | Data |
---|---|---|
c83027f3 NB |
1 | /* Functions used by the Windows port of libgccjit. |
2 | Copyright (C) 2020 Free Software Foundation, Inc. | |
3 | Contributed by Nicolas Bertolo <nicolasbertolo@gmail.com>. | |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it | |
8 | under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 3, or (at your option) | |
10 | any later version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but | |
13 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING3. If not see | |
19 | <http://www.gnu.org/licenses/>. */ | |
20 | ||
21 | #include "config.h" | |
22 | ||
23 | /* Required for rand_s */ | |
24 | #define _CRT_RAND_S | |
25 | ||
26 | #include <cstdio> | |
27 | #include <cstdint> | |
28 | ||
29 | #include "jit-w32.h" | |
30 | ||
31 | #include "libiberty.h" | |
32 | ||
33 | #include <accctrl.h> | |
34 | #include <aclapi.h> | |
35 | ||
36 | namespace gcc { | |
37 | namespace jit { | |
38 | void | |
39 | print_last_error (void) | |
40 | { | |
41 | LPSTR psz = NULL; | |
42 | DWORD dwErrorCode; | |
43 | dwErrorCode = GetLastError(); | |
44 | const DWORD cchMsg = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | |
45 | | FORMAT_MESSAGE_IGNORE_INSERTS | |
46 | | FORMAT_MESSAGE_ALLOCATE_BUFFER | |
47 | | FORMAT_MESSAGE_MAX_WIDTH_MASK, | |
48 | NULL, | |
49 | dwErrorCode, | |
50 | MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), | |
51 | reinterpret_cast<LPSTR>(&psz), | |
52 | 0, | |
53 | NULL); | |
54 | if (cchMsg > 0) | |
55 | { | |
56 | fprintf (stderr, "%s\n", psz); | |
57 | LocalFree (psz); | |
58 | } | |
59 | else | |
60 | { | |
61 | fprintf (stderr, "Failed to retrieve error message string for error %lu\n", | |
62 | dwErrorCode); | |
63 | } | |
64 | } | |
65 | ||
66 | /* Helper function used for getting the SID belonging to the current user. */ | |
67 | static TOKEN_USER* | |
68 | get_TOKEN_USER_current_user () | |
69 | { | |
70 | TOKEN_USER *result = NULL; | |
71 | ||
72 | HANDLE process_token = INVALID_HANDLE_VALUE; | |
73 | ||
74 | DWORD token_user_info_len; | |
75 | TOKEN_USER *token_user = NULL; | |
76 | ||
77 | /* Get current process access token. */ | |
78 | if (!OpenProcessToken (GetCurrentProcess (), TOKEN_READ, | |
79 | &process_token)) | |
80 | return NULL; | |
81 | ||
82 | /* Get necessary buffer size. */ | |
83 | if (!GetTokenInformation(process_token, TokenUser, NULL, 0, &token_user_info_len) | |
84 | && GetLastError() != ERROR_INSUFFICIENT_BUFFER) | |
85 | goto cleanup; | |
86 | ||
87 | token_user = (TOKEN_USER*) new char[token_user_info_len]; | |
88 | ||
89 | /* Get info about the user of the process */ | |
90 | if (!GetTokenInformation (process_token, TokenUser, token_user, | |
91 | token_user_info_len, &token_user_info_len)) | |
92 | goto cleanup; | |
93 | ||
94 | result = token_user; | |
95 | ||
96 | cleanup: | |
97 | if (process_token != INVALID_HANDLE_VALUE) | |
98 | CloseHandle(process_token); | |
99 | ||
100 | if (token_user != NULL && result == NULL) | |
101 | delete[] (char*)token_user; | |
102 | ||
103 | return result; | |
104 | } | |
105 | ||
106 | /* Helper function to create a directory with permissions such that only the | |
107 | current user can access it. */ | |
108 | static bool | |
109 | create_directory_for_current_user (const char * path) | |
110 | { | |
111 | PACL pACL = NULL; | |
112 | EXPLICIT_ACCESS ea; | |
113 | SECURITY_ATTRIBUTES sa; | |
114 | SECURITY_DESCRIPTOR SD; | |
115 | DWORD dwRes; | |
116 | bool result = true; | |
117 | TOKEN_USER *token_user = NULL; | |
118 | ||
119 | token_user = get_TOKEN_USER_current_user(); | |
120 | if (!token_user) | |
121 | return false; | |
122 | ||
123 | memset (&ea, 0, sizeof (EXPLICIT_ACCESS)); | |
124 | ea.grfAccessPermissions = GENERIC_ALL; /* Access to all. */ | |
125 | ea.grfAccessMode = SET_ACCESS; /* Set access and revoke everything else. */ | |
126 | /* This is necessary for the Windows Explorer GUI to show the correct tick | |
127 | boxes in the "Security" tab. */ | |
128 | ea.grfInheritance = OBJECT_INHERIT_ACE | CONTAINER_INHERIT_ACE; | |
129 | ea.Trustee.TrusteeForm = TRUSTEE_IS_SID; | |
130 | ea.Trustee.TrusteeType = TRUSTEE_IS_USER; | |
131 | ea.Trustee.ptstrName = (char*) token_user->User.Sid; | |
132 | ||
133 | /* Create a new ACL that contains the new ACEs. */ | |
134 | dwRes = SetEntriesInAcl(1, &ea, NULL, &pACL); | |
135 | if (dwRes != ERROR_SUCCESS) | |
136 | return false; | |
137 | ||
138 | if (!InitializeSecurityDescriptor (&SD, | |
139 | SECURITY_DESCRIPTOR_REVISION)) | |
140 | goto cleanup; | |
141 | ||
142 | /* Add the ACL to the security descriptor. */ | |
143 | if (!SetSecurityDescriptorDacl (&SD, | |
144 | TRUE, /* use pACL */ | |
145 | pACL, | |
146 | FALSE)) /* not a default DACL */ | |
147 | goto cleanup; | |
148 | ||
149 | /* Initialize a security attributes structure. */ | |
150 | sa.nLength = sizeof (SECURITY_ATTRIBUTES); | |
151 | sa.lpSecurityDescriptor = &SD; | |
152 | sa.bInheritHandle = FALSE; | |
153 | ||
154 | /* Finally create the directory */ | |
155 | if (!CreateDirectoryA (path, &sa)) | |
156 | result = false; | |
157 | ||
158 | cleanup: | |
159 | if (pACL) | |
160 | LocalFree (pACL); | |
161 | ||
162 | if (token_user) | |
163 | delete[] (char*)token_user; | |
164 | ||
165 | return result; | |
166 | } | |
167 | ||
168 | ||
169 | char * | |
170 | win_mkdtemp (void) | |
171 | { | |
172 | char lpTempPathBuffer[MAX_PATH]; | |
173 | ||
174 | /* Gets the temp path env string (no guarantee it's a valid path). */ | |
175 | DWORD dwRetVal = GetTempPath (MAX_PATH, lpTempPathBuffer); | |
176 | if (dwRetVal > MAX_PATH || (dwRetVal == 0)) | |
177 | { | |
178 | print_last_error (); | |
179 | return NULL; | |
180 | } | |
181 | ||
182 | /* Check that the directory actually exists. */ | |
183 | DWORD dwAttrib = GetFileAttributes (lpTempPathBuffer); | |
184 | bool temp_path_exists = (dwAttrib != INVALID_FILE_ATTRIBUTES | |
185 | && (dwAttrib & FILE_ATTRIBUTE_DIRECTORY)); | |
186 | if (!temp_path_exists) | |
187 | { | |
188 | fprintf (stderr, "Path returned by GetTempPath does not exist: %s\n", | |
189 | lpTempPathBuffer); | |
190 | } | |
191 | ||
192 | /* Make sure there is enough space in the buffer for the prefix and random | |
193 | number.*/ | |
194 | int temp_path_buffer_len = dwRetVal; | |
195 | const int appended_len = strlen ("\\libgccjit-123456"); | |
196 | if (temp_path_buffer_len + appended_len + 1 >= MAX_PATH) | |
197 | { | |
198 | fprintf (stderr, "Temporary file path too long for generation of random" | |
199 | " directories: %s", lpTempPathBuffer); | |
200 | } | |
201 | ||
202 | /* This is all the space we have in the buffer to store the random number and | |
203 | prefix. */ | |
204 | int extraspace = MAX_PATH - temp_path_buffer_len - 1; | |
205 | ||
206 | int tries; | |
207 | const int max_tries = 1000; | |
208 | ||
209 | for (tries = 0; tries < max_tries; ++tries) | |
210 | { | |
211 | /* Get a random number in [0; UINT_MAX]. */ | |
212 | unsigned int rand_num; | |
213 | if (rand_s (&rand_num) != 0) | |
214 | { | |
215 | fprintf (stderr, | |
216 | "Failed to create a random number using rand_s(): %s\n", | |
217 | _strerror (NULL)); | |
218 | return NULL; | |
219 | } | |
220 | ||
221 | /* Create 6 digits random number. */ | |
222 | rand_num = ((double)rand_num / ((double) UINT_MAX + 1 ) * 1000000); | |
223 | ||
224 | /* Copy the prefix and random number to the buffer. */ | |
225 | snprintf (&lpTempPathBuffer[temp_path_buffer_len], extraspace, | |
226 | "\\libgccjit-%06u", rand_num); | |
227 | ||
228 | if (create_directory_for_current_user (lpTempPathBuffer)) | |
229 | break; // success! | |
230 | ||
231 | /* If we can't create the directory because we got unlucky and the | |
232 | directory already exists retry, otherwise fail. */ | |
233 | if (GetLastError () != ERROR_ALREADY_EXISTS) | |
234 | { | |
235 | print_last_error (); | |
236 | return NULL; | |
237 | } | |
238 | } | |
239 | ||
240 | if (tries == max_tries) | |
241 | { | |
242 | fprintf (stderr, "Failed to create a random directory in %s\n", | |
243 | lpTempPathBuffer); | |
244 | return NULL; | |
245 | } | |
246 | ||
247 | { | |
248 | int allocate_len = temp_path_buffer_len + appended_len + 1; | |
249 | char * result = XNEWVEC (char, allocate_len); | |
250 | strcpy (result, lpTempPathBuffer); | |
251 | return result; | |
252 | } | |
253 | } | |
254 | } | |
255 | } |