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__create_stdio_pipe_pair(uv_loop_t * loop,uv_pipe_t * server_pipe,HANDLE * child_pipe_ptr,unsigned int flags)98 static int uv__create_stdio_pipe_pair(uv_loop_t* loop,
99 uv_pipe_t* server_pipe, HANDLE* child_pipe_ptr, unsigned int flags) {
100 char pipe_name[64];
101 SECURITY_ATTRIBUTES sa;
102 DWORD server_access = 0;
103 DWORD client_access = 0;
104 HANDLE child_pipe = INVALID_HANDLE_VALUE;
105 int err;
106
107 if (flags & UV_READABLE_PIPE) {
108 /* The server needs inbound access too, otherwise CreateNamedPipe() */
109 /* won't give us the FILE_READ_ATTRIBUTES permission. We need that to */
110 /* probe the state of the write buffer when we're trying to shutdown */
111 /* the pipe. */
112 server_access |= PIPE_ACCESS_OUTBOUND | PIPE_ACCESS_INBOUND;
113 client_access |= GENERIC_READ | FILE_WRITE_ATTRIBUTES;
114 }
115 if (flags & UV_WRITABLE_PIPE) {
116 server_access |= PIPE_ACCESS_INBOUND;
117 client_access |= GENERIC_WRITE | FILE_READ_ATTRIBUTES;
118 }
119
120 /* Create server pipe handle. */
121 err = uv_stdio_pipe_server(loop,
122 server_pipe,
123 server_access,
124 pipe_name,
125 sizeof(pipe_name));
126 if (err)
127 goto error;
128
129 /* Create child pipe handle. */
130 sa.nLength = sizeof sa;
131 sa.lpSecurityDescriptor = NULL;
132 sa.bInheritHandle = TRUE;
133
134 child_pipe = CreateFileA(pipe_name,
135 client_access,
136 0,
137 &sa,
138 OPEN_EXISTING,
139 server_pipe->ipc ? FILE_FLAG_OVERLAPPED : 0,
140 NULL);
141 if (child_pipe == INVALID_HANDLE_VALUE) {
142 err = GetLastError();
143 goto error;
144 }
145
146 #ifndef NDEBUG
147 /* Validate that the pipe was opened in the right mode. */
148 {
149 DWORD mode;
150 BOOL r = GetNamedPipeHandleState(child_pipe,
151 &mode,
152 NULL,
153 NULL,
154 NULL,
155 NULL,
156 0);
157 assert(r == TRUE);
158 assert(mode == (PIPE_READMODE_BYTE | PIPE_WAIT));
159 }
160 #endif
161
162 /* Do a blocking ConnectNamedPipe. This should not block because we have */
163 /* both ends of the pipe created. */
164 if (!ConnectNamedPipe(server_pipe->handle, NULL)) {
165 if (GetLastError() != ERROR_PIPE_CONNECTED) {
166 err = GetLastError();
167 goto error;
168 }
169 }
170
171 /* The server end is now readable and/or writable. */
172 if (flags & UV_READABLE_PIPE)
173 server_pipe->flags |= UV_HANDLE_WRITABLE;
174 if (flags & UV_WRITABLE_PIPE)
175 server_pipe->flags |= UV_HANDLE_READABLE;
176
177 *child_pipe_ptr = child_pipe;
178 return 0;
179
180 error:
181 if (server_pipe->handle != INVALID_HANDLE_VALUE) {
182 uv_pipe_cleanup(loop, server_pipe);
183 }
184
185 if (child_pipe != INVALID_HANDLE_VALUE) {
186 CloseHandle(child_pipe);
187 }
188
189 return err;
190 }
191
192
uv__duplicate_handle(uv_loop_t * loop,HANDLE handle,HANDLE * dup)193 static int uv__duplicate_handle(uv_loop_t* loop, HANDLE handle, HANDLE* dup) {
194 HANDLE current_process;
195
196
197 /* _get_osfhandle will sometimes return -2 in case of an error. This seems */
198 /* to happen when fd <= 2 and the process' corresponding stdio handle is */
199 /* set to NULL. Unfortunately DuplicateHandle will happily duplicate */
200 /* (HANDLE) -2, so this situation goes unnoticed until someone tries to */
201 /* use the duplicate. Therefore we filter out known-invalid handles here. */
202 if (handle == INVALID_HANDLE_VALUE ||
203 handle == NULL ||
204 handle == (HANDLE) -2) {
205 *dup = INVALID_HANDLE_VALUE;
206 return ERROR_INVALID_HANDLE;
207 }
208
209 current_process = GetCurrentProcess();
210
211 if (!DuplicateHandle(current_process,
212 handle,
213 current_process,
214 dup,
215 0,
216 TRUE,
217 DUPLICATE_SAME_ACCESS)) {
218 *dup = INVALID_HANDLE_VALUE;
219 return GetLastError();
220 }
221
222 return 0;
223 }
224
225
uv__duplicate_fd(uv_loop_t * loop,int fd,HANDLE * dup)226 static int uv__duplicate_fd(uv_loop_t* loop, int fd, HANDLE* dup) {
227 HANDLE handle;
228
229 if (fd == -1) {
230 *dup = INVALID_HANDLE_VALUE;
231 return ERROR_INVALID_HANDLE;
232 }
233
234 handle = uv__get_osfhandle(fd);
235 return uv__duplicate_handle(loop, handle, dup);
236 }
237
238
uv__create_nul_handle(HANDLE * handle_ptr,DWORD access)239 int uv__create_nul_handle(HANDLE* handle_ptr,
240 DWORD access) {
241 HANDLE handle;
242 SECURITY_ATTRIBUTES sa;
243
244 sa.nLength = sizeof sa;
245 sa.lpSecurityDescriptor = NULL;
246 sa.bInheritHandle = TRUE;
247
248 handle = CreateFileW(L"NUL",
249 access,
250 FILE_SHARE_READ | FILE_SHARE_WRITE,
251 &sa,
252 OPEN_EXISTING,
253 0,
254 NULL);
255 if (handle == INVALID_HANDLE_VALUE) {
256 return GetLastError();
257 }
258
259 *handle_ptr = handle;
260 return 0;
261 }
262
263
uv__stdio_create(uv_loop_t * loop,const uv_process_options_t * options,BYTE ** buffer_ptr)264 int uv__stdio_create(uv_loop_t* loop,
265 const uv_process_options_t* options,
266 BYTE** buffer_ptr) {
267 BYTE* buffer;
268 int count, i;
269 int err;
270
271 count = options->stdio_count;
272
273 if (count < 0 || count > 255) {
274 /* Only support FDs 0-255 */
275 return ERROR_NOT_SUPPORTED;
276 } else if (count < 3) {
277 /* There should always be at least 3 stdio handles. */
278 count = 3;
279 }
280
281 /* Allocate the child stdio buffer */
282 buffer = (BYTE*) malloc(CHILD_STDIO_SIZE(count));
283 if (buffer == NULL) {
284 return ERROR_OUTOFMEMORY;
285 }
286
287 /* Prepopulate the buffer with INVALID_HANDLE_VALUE handles so we can */
288 /* clean up on failure. */
289 CHILD_STDIO_COUNT(buffer) = count;
290 for (i = 0; i < count; i++) {
291 CHILD_STDIO_CRT_FLAGS(buffer, i) = 0;
292 CHILD_STDIO_HANDLE(buffer, i) = INVALID_HANDLE_VALUE;
293 }
294
295 for (i = 0; i < count; i++) {
296 uv_stdio_container_t fdopt;
297 if (i < options->stdio_count) {
298 fdopt = options->stdio[i];
299 } else {
300 fdopt.flags = UV_IGNORE;
301 }
302
303 switch (fdopt.flags & (UV_IGNORE | UV_CREATE_PIPE | UV_INHERIT_FD |
304 UV_INHERIT_STREAM)) {
305 case UV_IGNORE:
306 /* Starting a process with no stdin/stout/stderr can confuse it. */
307 /* So no matter what the user specified, we make sure the first */
308 /* three FDs are always open in their typical modes, e.g. stdin */
309 /* be readable and stdout/err should be writable. For FDs > 2, don't */
310 /* do anything - all handles in the stdio buffer are initialized with */
311 /* INVALID_HANDLE_VALUE, which should be okay. */
312 if (i <= 2) {
313 DWORD access = (i == 0) ? FILE_GENERIC_READ :
314 FILE_GENERIC_WRITE | FILE_READ_ATTRIBUTES;
315
316 err = uv__create_nul_handle(&CHILD_STDIO_HANDLE(buffer, i),
317 access);
318 if (err)
319 goto error;
320
321 CHILD_STDIO_CRT_FLAGS(buffer, i) = FOPEN | FDEV;
322 }
323 break;
324
325 case UV_CREATE_PIPE: {
326 /* Create a pair of two connected pipe ends; one end is turned into */
327 /* an uv_pipe_t for use by the parent. The other one is given to */
328 /* the child. */
329 uv_pipe_t* parent_pipe = (uv_pipe_t*) fdopt.data.stream;
330 HANDLE child_pipe;
331
332 /* Create a new, connected pipe pair. stdio[i].stream should point */
333 /* to an uninitialized, but not connected pipe handle. */
334 assert(fdopt.data.stream->type == UV_NAMED_PIPE);
335 assert(!(fdopt.data.stream->flags & UV_HANDLE_CONNECTION));
336 assert(!(fdopt.data.stream->flags & UV_HANDLE_PIPESERVER));
337
338 err = uv__create_stdio_pipe_pair(loop,
339 parent_pipe,
340 &child_pipe,
341 fdopt.flags);
342 if (err)
343 goto error;
344
345 CHILD_STDIO_HANDLE(buffer, i) = child_pipe;
346 CHILD_STDIO_CRT_FLAGS(buffer, i) = FOPEN | FPIPE;
347 break;
348 }
349
350 case UV_INHERIT_FD: {
351 /* Inherit a raw FD. */
352 HANDLE child_handle;
353
354 /* Make an inheritable duplicate of the handle. */
355 err = uv__duplicate_fd(loop, fdopt.data.fd, &child_handle);
356 if (err) {
357 /* If fdopt.data.fd is not valid and fd fd <= 2, then ignore the */
358 /* error. */
359 if (fdopt.data.fd <= 2 && err == ERROR_INVALID_HANDLE) {
360 CHILD_STDIO_CRT_FLAGS(buffer, i) = 0;
361 CHILD_STDIO_HANDLE(buffer, i) = INVALID_HANDLE_VALUE;
362 break;
363 }
364 goto error;
365 }
366
367 /* Figure out what the type is. */
368 switch (GetFileType(child_handle)) {
369 case FILE_TYPE_DISK:
370 CHILD_STDIO_CRT_FLAGS(buffer, i) = FOPEN;
371 break;
372
373 case FILE_TYPE_PIPE:
374 CHILD_STDIO_CRT_FLAGS(buffer, i) = FOPEN | FPIPE;
375
376 case FILE_TYPE_CHAR:
377 case FILE_TYPE_REMOTE:
378 CHILD_STDIO_CRT_FLAGS(buffer, i) = FOPEN | FDEV;
379 break;
380
381 case FILE_TYPE_UNKNOWN:
382 if (GetLastError() != 0) {
383 err = GetLastError();
384 CloseHandle(child_handle);
385 goto error;
386 }
387 CHILD_STDIO_CRT_FLAGS(buffer, i) = FOPEN | FDEV;
388 break;
389
390 default:
391 assert(0);
392 }
393
394 CHILD_STDIO_HANDLE(buffer, i) = child_handle;
395 break;
396 }
397
398 case UV_INHERIT_STREAM: {
399 /* Use an existing stream as the stdio handle for the child. */
400 HANDLE stream_handle, child_handle;
401 unsigned char crt_flags;
402 uv_stream_t* stream = fdopt.data.stream;
403
404 /* Leech the handle out of the stream. */
405 if (stream->type == UV_TTY) {
406 stream_handle = ((uv_tty_t*) stream)->handle;
407 crt_flags = FOPEN | FDEV;
408 } else if (stream->type == UV_NAMED_PIPE &&
409 stream->flags & UV_HANDLE_CONNECTED) {
410 stream_handle = ((uv_pipe_t*) stream)->handle;
411 crt_flags = FOPEN | FPIPE;
412 } else {
413 stream_handle = INVALID_HANDLE_VALUE;
414 crt_flags = 0;
415 }
416
417 if (stream_handle == NULL ||
418 stream_handle == INVALID_HANDLE_VALUE) {
419 /* The handle is already closed, or not yet created, or the */
420 /* stream type is not supported. */
421 err = ERROR_NOT_SUPPORTED;
422 goto error;
423 }
424
425 /* Make an inheritable copy of the handle. */
426 if (uv__duplicate_handle(loop,
427 stream_handle,
428 &child_handle) < 0) {
429 goto error;
430 }
431
432 CHILD_STDIO_HANDLE(buffer, i) = child_handle;
433 CHILD_STDIO_CRT_FLAGS(buffer, i) = crt_flags;
434 break;
435 }
436
437 default:
438 assert(0);
439 }
440 }
441
442 *buffer_ptr = buffer;
443 return 0;
444
445 error:
446 uv__stdio_destroy(buffer);
447 return err;
448 }
449
450
uv__stdio_destroy(BYTE * buffer)451 void uv__stdio_destroy(BYTE* buffer) {
452 int i, count;
453
454 count = CHILD_STDIO_COUNT(buffer);
455 for (i = 0; i < count; i++) {
456 HANDLE handle = CHILD_STDIO_HANDLE(buffer, i);
457 if (handle != INVALID_HANDLE_VALUE) {
458 CloseHandle(handle);
459 }
460 }
461
462 free(buffer);
463 }
464
465
uv__stdio_noinherit(BYTE * buffer)466 void uv__stdio_noinherit(BYTE* buffer) {
467 int i, count;
468
469 count = CHILD_STDIO_COUNT(buffer);
470 for (i = 0; i < count; i++) {
471 HANDLE handle = CHILD_STDIO_HANDLE(buffer, i);
472 if (handle != INVALID_HANDLE_VALUE) {
473 SetHandleInformation(handle, HANDLE_FLAG_INHERIT, 0);
474 }
475 }
476 }
477
478
uv__stdio_verify(BYTE * buffer,WORD size)479 int uv__stdio_verify(BYTE* buffer, WORD size) {
480 unsigned int count;
481
482 /* Check the buffer pointer. */
483 if (buffer == NULL)
484 return 0;
485
486 /* Verify that the buffer is at least big enough to hold the count. */
487 if (size < CHILD_STDIO_SIZE(0))
488 return 0;
489
490 /* Verify if the count is within range. */
491 count = CHILD_STDIO_COUNT(buffer);
492 if (count > 256)
493 return 0;
494
495 /* Verify that the buffer size is big enough to hold info for N FDs. */
496 if (size < CHILD_STDIO_SIZE(count))
497 return 0;
498
499 return 1;
500 }
501
502
uv__stdio_size(BYTE * buffer)503 WORD uv__stdio_size(BYTE* buffer) {
504 return (WORD) CHILD_STDIO_SIZE(CHILD_STDIO_COUNT((buffer)));
505 }
506
507
uv__stdio_handle(BYTE * buffer,int fd)508 HANDLE uv__stdio_handle(BYTE* buffer, int fd) {
509 return CHILD_STDIO_HANDLE(buffer, fd);
510 }
511