1 /* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
2 *
3 * Permission is hereby granted, free of charge, to any person obtaining a copy
4 * of this software and associated documentation files (the "Software"), to
5 * deal in the Software without restriction, including without limitation the
6 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
7 * sell copies of the Software, and to permit persons to whom the Software is
8 * furnished to do so, subject to the following conditions:
9 *
10 * The above copyright notice and this permission notice shall be included in
11 * all copies or substantial portions of the Software.
12 *
13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
18 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
19 * IN THE SOFTWARE.
20 */
21
22 #include <assert.h>
23 #include <io.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26
27 #include "uv.h"
28 #include "internal.h"
29 #include "handle-inl.h"
30
31
32 /*
33 * The `child_stdio_buffer` buffer has the following layout:
34 * int number_of_fds
35 * unsigned char crt_flags[number_of_fds]
36 * HANDLE os_handle[number_of_fds]
37 */
38 #define CHILD_STDIO_SIZE(count) \
39 (sizeof(int) + \
40 sizeof(unsigned char) * (count) + \
41 sizeof(uintptr_t) * (count))
42
43 #define CHILD_STDIO_COUNT(buffer) \
44 *((unsigned int*) (buffer))
45
46 #define CHILD_STDIO_CRT_FLAGS(buffer, fd) \
47 *((unsigned char*) (buffer) + sizeof(int) + fd)
48
49 #define CHILD_STDIO_HANDLE(buffer, fd) \
50 *((HANDLE*) ((unsigned char*) (buffer) + \
51 sizeof(int) + \
52 sizeof(unsigned char) * \
53 CHILD_STDIO_COUNT((buffer)) + \
54 sizeof(HANDLE) * (fd)))
55
56
57 /* CRT file descriptor mode flags */
58 #define FOPEN 0x01
59 #define FEOFLAG 0x02
60 #define FCRLF 0x04
61 #define FPIPE 0x08
62 #define FNOINHERIT 0x10
63 #define FAPPEND 0x20
64 #define FDEV 0x40
65 #define FTEXT 0x80
66
67
68 /*
69 * Clear the HANDLE_FLAG_INHERIT flag from all HANDLEs that were inherited
70 * the parent process. Don't check for errors - the stdio handles may not be
71 * valid, or may be closed already. There is no guarantee that this function
72 * does a perfect job.
73 */
uv_disable_stdio_inheritance(void)74 void uv_disable_stdio_inheritance(void) {
75 HANDLE handle;
76 STARTUPINFOW si;
77
78 /* Make the windows stdio handles non-inheritable. */
79 handle = GetStdHandle(STD_INPUT_HANDLE);
80 if (handle != NULL && handle != INVALID_HANDLE_VALUE)
81 SetHandleInformation(handle, HANDLE_FLAG_INHERIT, 0);
82
83 handle = GetStdHandle(STD_OUTPUT_HANDLE);
84 if (handle != NULL && handle != INVALID_HANDLE_VALUE)
85 SetHandleInformation(handle, HANDLE_FLAG_INHERIT, 0);
86
87 handle = GetStdHandle(STD_ERROR_HANDLE);
88 if (handle != NULL && handle != INVALID_HANDLE_VALUE)
89 SetHandleInformation(handle, HANDLE_FLAG_INHERIT, 0);
90
91 /* Make inherited CRT FDs non-inheritable. */
92 GetStartupInfoW(&si);
93 if (uv__stdio_verify(si.lpReserved2, si.cbReserved2))
94 uv__stdio_noinherit(si.lpReserved2);
95 }
96
97
uv__duplicate_handle(uv_loop_t * loop,HANDLE handle,HANDLE * dup)98 static int uv__duplicate_handle(uv_loop_t* loop, HANDLE handle, HANDLE* dup) {
99 HANDLE current_process;
100
101
102 /* _get_osfhandle will sometimes return -2 in case of an error. This seems to
103 * happen when fd <= 2 and the process' corresponding stdio handle is set to
104 * NULL. Unfortunately DuplicateHandle will happily duplicate (HANDLE) -2, so
105 * this situation goes unnoticed until someone tries to use the duplicate.
106 * Therefore we filter out known-invalid handles here. */
107 if (handle == INVALID_HANDLE_VALUE ||
108 handle == NULL ||
109 handle == (HANDLE) -2) {
110 *dup = INVALID_HANDLE_VALUE;
111 return ERROR_INVALID_HANDLE;
112 }
113
114 current_process = GetCurrentProcess();
115
116 if (!DuplicateHandle(current_process,
117 handle,
118 current_process,
119 dup,
120 0,
121 TRUE,
122 DUPLICATE_SAME_ACCESS)) {
123 *dup = INVALID_HANDLE_VALUE;
124 return GetLastError();
125 }
126
127 return 0;
128 }
129
130
uv__duplicate_fd(uv_loop_t * loop,int fd,HANDLE * dup)131 static int uv__duplicate_fd(uv_loop_t* loop, int fd, HANDLE* dup) {
132 HANDLE handle;
133
134 if (fd == -1) {
135 *dup = INVALID_HANDLE_VALUE;
136 return ERROR_INVALID_HANDLE;
137 }
138
139 handle = uv__get_osfhandle(fd);
140 return uv__duplicate_handle(loop, handle, dup);
141 }
142
143
uv__create_nul_handle(HANDLE * handle_ptr,DWORD access)144 int uv__create_nul_handle(HANDLE* handle_ptr,
145 DWORD access) {
146 HANDLE handle;
147 SECURITY_ATTRIBUTES sa;
148
149 sa.nLength = sizeof sa;
150 sa.lpSecurityDescriptor = NULL;
151 sa.bInheritHandle = TRUE;
152
153 handle = CreateFileW(L"NUL",
154 access,
155 FILE_SHARE_READ | FILE_SHARE_WRITE,
156 &sa,
157 OPEN_EXISTING,
158 0,
159 NULL);
160 if (handle == INVALID_HANDLE_VALUE) {
161 return GetLastError();
162 }
163
164 *handle_ptr = handle;
165 return 0;
166 }
167
168
uv__stdio_create(uv_loop_t * loop,const uv_process_options_t * options,BYTE ** buffer_ptr)169 int uv__stdio_create(uv_loop_t* loop,
170 const uv_process_options_t* options,
171 BYTE** buffer_ptr) {
172 BYTE* buffer;
173 int count, i;
174 int err;
175
176 count = options->stdio_count;
177
178 if (count < 0 || count > 255) {
179 /* Only support FDs 0-255 */
180 return ERROR_NOT_SUPPORTED;
181 } else if (count < 3) {
182 /* There should always be at least 3 stdio handles. */
183 count = 3;
184 }
185
186 /* Allocate the child stdio buffer */
187 buffer = (BYTE*) uv__malloc(CHILD_STDIO_SIZE(count));
188 if (buffer == NULL) {
189 return ERROR_OUTOFMEMORY;
190 }
191
192 /* Prepopulate the buffer with INVALID_HANDLE_VALUE handles so we can clean
193 * up on failure. */
194 CHILD_STDIO_COUNT(buffer) = count;
195 for (i = 0; i < count; i++) {
196 CHILD_STDIO_CRT_FLAGS(buffer, i) = 0;
197 CHILD_STDIO_HANDLE(buffer, i) = INVALID_HANDLE_VALUE;
198 }
199
200 for (i = 0; i < count; i++) {
201 uv_stdio_container_t fdopt;
202 if (i < options->stdio_count) {
203 fdopt = options->stdio[i];
204 } else {
205 fdopt.flags = UV_IGNORE;
206 }
207
208 switch (fdopt.flags & (UV_IGNORE | UV_CREATE_PIPE | UV_INHERIT_FD |
209 UV_INHERIT_STREAM)) {
210 case UV_IGNORE:
211 /* Starting a process with no stdin/stout/stderr can confuse it. So no
212 * matter what the user specified, we make sure the first three FDs are
213 * always open in their typical modes, e. g. stdin be readable and
214 * stdout/err should be writable. For FDs > 2, don't do anything - all
215 * handles in the stdio buffer are initialized with.
216 * INVALID_HANDLE_VALUE, which should be okay. */
217 if (i <= 2) {
218 DWORD access = (i == 0) ? FILE_GENERIC_READ :
219 FILE_GENERIC_WRITE | FILE_READ_ATTRIBUTES;
220
221 err = uv__create_nul_handle(&CHILD_STDIO_HANDLE(buffer, i),
222 access);
223 if (err)
224 goto error;
225
226 CHILD_STDIO_CRT_FLAGS(buffer, i) = FOPEN | FDEV;
227 }
228 break;
229
230 case UV_CREATE_PIPE: {
231 /* Create a pair of two connected pipe ends; one end is turned into an
232 * uv_pipe_t for use by the parent. The other one is given to the
233 * child. */
234 uv_pipe_t* parent_pipe = (uv_pipe_t*) fdopt.data.stream;
235 HANDLE child_pipe = INVALID_HANDLE_VALUE;
236
237 /* Create a new, connected pipe pair. stdio[i]. stream should point to
238 * an uninitialized, but not connected pipe handle. */
239 assert(fdopt.data.stream->type == UV_NAMED_PIPE);
240 assert(!(fdopt.data.stream->flags & UV_HANDLE_CONNECTION));
241 assert(!(fdopt.data.stream->flags & UV_HANDLE_PIPESERVER));
242
243 err = uv__create_stdio_pipe_pair(loop,
244 parent_pipe,
245 &child_pipe,
246 fdopt.flags);
247 if (err)
248 goto error;
249
250 CHILD_STDIO_HANDLE(buffer, i) = child_pipe;
251 CHILD_STDIO_CRT_FLAGS(buffer, i) = FOPEN | FPIPE;
252 break;
253 }
254
255 case UV_INHERIT_FD: {
256 /* Inherit a raw FD. */
257 HANDLE child_handle;
258
259 /* Make an inheritable duplicate of the handle. */
260 err = uv__duplicate_fd(loop, fdopt.data.fd, &child_handle);
261 if (err) {
262 /* If fdopt. data. fd is not valid and fd <= 2, then ignore the
263 * error. */
264 if (fdopt.data.fd <= 2 && err == ERROR_INVALID_HANDLE) {
265 CHILD_STDIO_CRT_FLAGS(buffer, i) = 0;
266 CHILD_STDIO_HANDLE(buffer, i) = INVALID_HANDLE_VALUE;
267 break;
268 }
269 goto error;
270 }
271
272 /* Figure out what the type is. */
273 switch (GetFileType(child_handle)) {
274 case FILE_TYPE_DISK:
275 CHILD_STDIO_CRT_FLAGS(buffer, i) = FOPEN;
276 break;
277
278 case FILE_TYPE_PIPE:
279 CHILD_STDIO_CRT_FLAGS(buffer, i) = FOPEN | FPIPE;
280 break;
281
282 case FILE_TYPE_CHAR:
283 case FILE_TYPE_REMOTE:
284 CHILD_STDIO_CRT_FLAGS(buffer, i) = FOPEN | FDEV;
285 break;
286
287 case FILE_TYPE_UNKNOWN:
288 if (GetLastError() != 0) {
289 err = GetLastError();
290 CloseHandle(child_handle);
291 goto error;
292 }
293 CHILD_STDIO_CRT_FLAGS(buffer, i) = FOPEN | FDEV;
294 break;
295
296 default:
297 assert(0);
298 return -1;
299 }
300
301 CHILD_STDIO_HANDLE(buffer, i) = child_handle;
302 break;
303 }
304
305 case UV_INHERIT_STREAM: {
306 /* Use an existing stream as the stdio handle for the child. */
307 HANDLE stream_handle, child_handle;
308 unsigned char crt_flags;
309 uv_stream_t* stream = fdopt.data.stream;
310
311 /* Leech the handle out of the stream. */
312 if (stream->type == UV_TTY) {
313 stream_handle = ((uv_tty_t*) stream)->handle;
314 crt_flags = FOPEN | FDEV;
315 } else if (stream->type == UV_NAMED_PIPE &&
316 stream->flags & UV_HANDLE_CONNECTION) {
317 stream_handle = ((uv_pipe_t*) stream)->handle;
318 crt_flags = FOPEN | FPIPE;
319 } else {
320 stream_handle = INVALID_HANDLE_VALUE;
321 crt_flags = 0;
322 }
323
324 if (stream_handle == NULL ||
325 stream_handle == INVALID_HANDLE_VALUE) {
326 /* The handle is already closed, or not yet created, or the stream
327 * type is not supported. */
328 err = ERROR_NOT_SUPPORTED;
329 goto error;
330 }
331
332 /* Make an inheritable copy of the handle. */
333 err = uv__duplicate_handle(loop, stream_handle, &child_handle);
334 if (err)
335 goto error;
336
337 CHILD_STDIO_HANDLE(buffer, i) = child_handle;
338 CHILD_STDIO_CRT_FLAGS(buffer, i) = crt_flags;
339 break;
340 }
341
342 default:
343 assert(0);
344 return -1;
345 }
346 }
347
348 *buffer_ptr = buffer;
349 return 0;
350
351 error:
352 uv__stdio_destroy(buffer);
353 return err;
354 }
355
356
uv__stdio_destroy(BYTE * buffer)357 void uv__stdio_destroy(BYTE* buffer) {
358 int i, count;
359
360 count = CHILD_STDIO_COUNT(buffer);
361 for (i = 0; i < count; i++) {
362 HANDLE handle = CHILD_STDIO_HANDLE(buffer, i);
363 if (handle != INVALID_HANDLE_VALUE) {
364 CloseHandle(handle);
365 }
366 }
367
368 uv__free(buffer);
369 }
370
371
uv__stdio_noinherit(BYTE * buffer)372 void uv__stdio_noinherit(BYTE* buffer) {
373 int i, count;
374
375 count = CHILD_STDIO_COUNT(buffer);
376 for (i = 0; i < count; i++) {
377 HANDLE handle = CHILD_STDIO_HANDLE(buffer, i);
378 if (handle != INVALID_HANDLE_VALUE) {
379 SetHandleInformation(handle, HANDLE_FLAG_INHERIT, 0);
380 }
381 }
382 }
383
384
uv__stdio_verify(BYTE * buffer,WORD size)385 int uv__stdio_verify(BYTE* buffer, WORD size) {
386 unsigned int count;
387
388 /* Check the buffer pointer. */
389 if (buffer == NULL)
390 return 0;
391
392 /* Verify that the buffer is at least big enough to hold the count. */
393 if (size < CHILD_STDIO_SIZE(0))
394 return 0;
395
396 /* Verify if the count is within range. */
397 count = CHILD_STDIO_COUNT(buffer);
398 if (count > 256)
399 return 0;
400
401 /* Verify that the buffer size is big enough to hold info for N FDs. */
402 if (size < CHILD_STDIO_SIZE(count))
403 return 0;
404
405 return 1;
406 }
407
408
uv__stdio_size(BYTE * buffer)409 WORD uv__stdio_size(BYTE* buffer) {
410 return (WORD) CHILD_STDIO_SIZE(CHILD_STDIO_COUNT((buffer)));
411 }
412
413
uv__stdio_handle(BYTE * buffer,int fd)414 HANDLE uv__stdio_handle(BYTE* buffer, int fd) {
415 return CHILD_STDIO_HANDLE(buffer, fd);
416 }
417
