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Commit | Line | Data |
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7b487ba9 CV |
1 | /* posix_ipc.cc: POSIX IPC API for Cygwin. |
2 | ||
7b487ba9 CV |
3 | This file is part of Cygwin. |
4 | ||
5 | This software is a copyrighted work licensed under the terms of the | |
6 | Cygwin license. Please consult the file "CYGWIN_LICENSE" for | |
7 | details. */ | |
8 | ||
7b487ba9 | 9 | #include "winsup.h" |
3748b3e8 | 10 | #include "shared_info.h" |
8fbd574e | 11 | #include "thread.h" |
7b487ba9 | 12 | #include "path.h" |
7b487ba9 | 13 | #include "cygtls.h" |
e6fbf13e CV |
14 | #include "fhandler.h" |
15 | #include "dtable.h" | |
16 | #include "cygheap.h" | |
7b487ba9 | 17 | #include "sigproc.h" |
abbde487 | 18 | #include "ntdll.h" |
b62450cf | 19 | #include "tls_pbuf.h" |
4fc922b2 | 20 | #include <io.h> |
7b487ba9 CV |
21 | #include <sys/mman.h> |
22 | #include <sys/param.h> | |
7b487ba9 | 23 | #include <stdlib.h> |
7b487ba9 | 24 | #include <unistd.h> |
7b487ba9 | 25 | #include <mqueue.h> |
8fbd574e | 26 | #include <semaphore.h> |
7b487ba9 | 27 | |
5f621bd3 | 28 | /* The prefix_len is the length of the path prefix including trailing "/" |
547ad329 | 29 | (or "/sem." for semaphores) as well as the trailing NUL. */ |
cb7e1879 | 30 | static struct |
7b487ba9 CV |
31 | { |
32 | const char *prefix; | |
547ad329 | 33 | const size_t prefix_len; |
7b487ba9 CV |
34 | const char *description; |
35 | } ipc_names[] = { | |
547ad329 CV |
36 | { "/dev/shm", 10, "POSIX shared memory object" }, |
37 | { "/dev/mqueue", 13, "POSIX message queue" }, | |
38 | { "/dev/shm", 14, "POSIX semaphore" } | |
7b487ba9 CV |
39 | }; |
40 | ||
41 | enum ipc_type_t | |
42 | { | |
43 | shmem, | |
44 | mqueue, | |
8fbd574e | 45 | semaphore |
7b487ba9 CV |
46 | }; |
47 | ||
48 | static bool | |
547ad329 | 49 | check_path (char *res_name, ipc_type_t type, const char *name, size_t len) |
7b487ba9 | 50 | { |
b32c31d1 | 51 | /* Note that we require the existance of the appropriate /dev subdirectories |
7b487ba9 CV |
52 | for POSIX IPC object support, similar to Linux (which supports the |
53 | directories, but doesn't require to mount them). We don't create | |
54 | these directory here, that's the task of the installer. But we check | |
55 | for existance and give ample warning. */ | |
56 | path_conv path (ipc_names[type].prefix, PC_SYM_NOFOLLOW); | |
57 | if (path.error || !path.exists () || !path.isdir ()) | |
58 | { | |
59 | small_printf ( | |
60 | "Warning: '%s' does not exists or is not a directory.\n\n" | |
61 | "%ss require the existance of this directory.\n" | |
62 | "Create the directory '%s' and set the permissions to 01777.\n" | |
63 | "For instance on the command line: mkdir -m 01777 %s\n", | |
64 | ipc_names[type].prefix, ipc_names[type].description, | |
65 | ipc_names[type].prefix, ipc_names[type].prefix); | |
66 | set_errno (EINVAL); | |
67 | return false; | |
68 | } | |
5b380b1c | 69 | /* Apart from handling backslash like slash, the naming rules are identical |
b32c31d1 CV |
70 | to Linux, including the names and requirements for subdirectories, if |
71 | the name contains further slashes. */ | |
5b380b1c CV |
72 | /* Name must not be empty and has to start with a slash (or backslash) */ |
73 | if (!name || !strchr ("/\\", name[0])) | |
7b487ba9 CV |
74 | { |
75 | debug_printf ("Invalid %s name '%s'", ipc_names[type].description, name); | |
76 | set_errno (EINVAL); | |
77 | return false; | |
78 | } | |
5b380b1c CV |
79 | /* Name must not consist of just a single slash (or backslash) */ |
80 | if (!name[1]) | |
81 | { | |
82 | debug_printf ("Invalid %s name '%s'", ipc_names[type].description, name); | |
83 | set_errno (ENOENT); | |
84 | return false; | |
85 | } | |
86 | /* Name must not contain slashes after the leading one */ | |
87 | if (strpbrk (name + 1, "/\\")) | |
88 | { | |
89 | debug_printf ("Invalid %s name '%s'", ipc_names[type].description, name); | |
90 | set_errno (EACCES); | |
91 | return false; | |
92 | } | |
93 | /* Length must be less than or equal to NAME_MAX, or NAME_MAX - 4 in | |
94 | case of semaphores, due to the leading "sem." prefix */ | |
95 | if (len > NAME_MAX - (type == semaphore ? strlen ("sem.") : 0)) | |
7b487ba9 CV |
96 | { |
97 | debug_printf ("%s name '%s' too long", ipc_names[type].description, name); | |
98 | set_errno (ENAMETOOLONG); | |
99 | return false; | |
100 | } | |
8fbd574e CV |
101 | __small_sprintf (res_name, "%s/%s%s", ipc_names[type].prefix, |
102 | type == semaphore ? "sem." : "", | |
5b380b1c | 103 | name + 1); |
7b487ba9 CV |
104 | return true; |
105 | } | |
106 | ||
7b487ba9 | 107 | static int |
c6d1382a | 108 | ipc_mutex_lock (HANDLE mtx, bool eintr) |
7b487ba9 | 109 | { |
c6d1382a CV |
110 | switch (cygwait (mtx, cw_infinite, cw_cancel | cw_cancel_self |
111 | | (eintr ? cw_sig_eintr : cw_sig_restart))) | |
7b44665a | 112 | { |
7b487ba9 CV |
113 | case WAIT_OBJECT_0: |
114 | case WAIT_ABANDONED_0: | |
115 | return 0; | |
962f9a2c | 116 | case WAIT_SIGNALED: |
7b487ba9 CV |
117 | set_errno (EINTR); |
118 | return 1; | |
119 | default: | |
120 | break; | |
7b44665a | 121 | } |
7b487ba9 CV |
122 | return geterrno_from_win_error (); |
123 | } | |
124 | ||
125 | static inline int | |
126 | ipc_mutex_unlock (HANDLE mtx) | |
127 | { | |
128 | return ReleaseMutex (mtx) ? 0 : geterrno_from_win_error (); | |
129 | } | |
130 | ||
7b487ba9 CV |
131 | static int |
132 | ipc_cond_timedwait (HANDLE evt, HANDLE mtx, const struct timespec *abstime) | |
133 | { | |
962f9a2c | 134 | HANDLE w4[4] = { evt, }; |
86bf572e | 135 | DWORD cnt = 2; |
206a6ee9 | 136 | DWORD timer_idx = 0; |
86bf572e CV |
137 | int ret = 0; |
138 | ||
c43e9340 | 139 | wait_signal_arrived here (w4[1]); |
a91ac4dc CV |
140 | if ((w4[cnt] = pthread::get_cancel_event ()) != NULL) |
141 | ++cnt; | |
86bf572e CV |
142 | if (abstime) |
143 | { | |
397526de | 144 | if (!valid_timespec (*abstime)) |
86bf572e CV |
145 | return EINVAL; |
146 | ||
147 | /* If a timeout is set, we create a waitable timer to wait for. | |
148 | This is the easiest way to handle the absolute timeout value, given | |
149 | that NtSetTimer also takes absolute times and given the double | |
150 | dependency on evt *and* mtx, which requires to call WFMO twice. */ | |
151 | NTSTATUS status; | |
152 | LARGE_INTEGER duetime; | |
153 | ||
206a6ee9 CV |
154 | timer_idx = cnt++; |
155 | status = NtCreateTimer (&w4[timer_idx], TIMER_ALL_ACCESS, NULL, | |
86bf572e CV |
156 | NotificationTimer); |
157 | if (!NT_SUCCESS (status)) | |
158 | return geterrno_from_nt_status (status); | |
0ff057d5 | 159 | timespec_to_filetime (abstime, &duetime); |
206a6ee9 | 160 | status = NtSetTimer (w4[timer_idx], &duetime, NULL, NULL, FALSE, 0, NULL); |
86bf572e CV |
161 | if (!NT_SUCCESS (status)) |
162 | { | |
206a6ee9 | 163 | NtClose (w4[timer_idx]); |
86bf572e CV |
164 | return geterrno_from_nt_status (status); |
165 | } | |
7b487ba9 | 166 | } |
3748b3e8 | 167 | ResetEvent (evt); |
86bf572e CV |
168 | if ((ret = ipc_mutex_unlock (mtx)) != 0) |
169 | return ret; | |
170 | /* Everything's set up, so now wait for the event to be signalled. */ | |
171 | restart1: | |
172 | switch (WaitForMultipleObjects (cnt, w4, FALSE, INFINITE)) | |
7b44665a | 173 | { |
7b487ba9 | 174 | case WAIT_OBJECT_0: |
86bf572e CV |
175 | break; |
176 | case WAIT_OBJECT_0 + 1: | |
177 | if (_my_tls.call_signal_handler ()) | |
178 | goto restart1; | |
179 | ret = EINTR; | |
180 | break; | |
181 | case WAIT_OBJECT_0 + 2: | |
206a6ee9 | 182 | if (timer_idx != 2) |
b86f999a | 183 | pthread::static_cancel_self (); |
50ad1980 | 184 | fallthrough; |
206a6ee9 | 185 | case WAIT_OBJECT_0 + 3: |
86bf572e CV |
186 | ret = ETIMEDOUT; |
187 | break; | |
7b487ba9 | 188 | default: |
86bf572e | 189 | ret = geterrno_from_win_error (); |
7b487ba9 | 190 | break; |
7b44665a | 191 | } |
86bf572e CV |
192 | if (ret == 0) |
193 | { | |
194 | /* At this point we need to lock the mutex. The wait is practically | |
195 | the same as before, just that we now wait on the mutex instead of the | |
196 | event. */ | |
197 | restart2: | |
198 | w4[0] = mtx; | |
199 | switch (WaitForMultipleObjects (cnt, w4, FALSE, INFINITE)) | |
200 | { | |
201 | case WAIT_OBJECT_0: | |
202 | case WAIT_ABANDONED_0: | |
203 | break; | |
204 | case WAIT_OBJECT_0 + 1: | |
205 | if (_my_tls.call_signal_handler ()) | |
206 | goto restart2; | |
207 | ret = EINTR; | |
208 | break; | |
209 | case WAIT_OBJECT_0 + 2: | |
206a6ee9 CV |
210 | if (timer_idx != 2) |
211 | pthread_testcancel (); | |
50ad1980 | 212 | fallthrough; |
206a6ee9 | 213 | case WAIT_OBJECT_0 + 3: |
86bf572e CV |
214 | ret = ETIMEDOUT; |
215 | break; | |
216 | default: | |
217 | ret = geterrno_from_win_error (); | |
218 | break; | |
219 | } | |
220 | } | |
206a6ee9 | 221 | if (timer_idx) |
86bf572e CV |
222 | { |
223 | if (ret != ETIMEDOUT) | |
206a6ee9 CV |
224 | NtCancelTimer (w4[timer_idx], NULL); |
225 | NtClose (w4[timer_idx]); | |
86bf572e CV |
226 | } |
227 | return ret; | |
7b487ba9 CV |
228 | } |
229 | ||
86bf572e | 230 | static inline void |
7b487ba9 CV |
231 | ipc_cond_signal (HANDLE evt) |
232 | { | |
86bf572e | 233 | SetEvent (evt); |
7b487ba9 CV |
234 | } |
235 | ||
8fbd574e CV |
236 | class ipc_flock |
237 | { | |
61522196 | 238 | struct flock fl; |
8fbd574e CV |
239 | |
240 | public: | |
241 | ipc_flock () { memset (&fl, 0, sizeof fl); } | |
242 | ||
243 | int lock (int fd, size_t size) | |
244 | { | |
245 | fl.l_type = F_WRLCK; | |
246 | fl.l_whence = SEEK_SET; | |
247 | fl.l_start = 0; | |
248 | fl.l_len = size; | |
fabfb1a1 | 249 | return fcntl64 (fd, F_SETLKW, &fl); |
8fbd574e CV |
250 | } |
251 | int unlock (int fd) | |
252 | { | |
253 | if (!fl.l_len) | |
254 | return 0; | |
255 | fl.l_type = F_UNLCK; | |
fabfb1a1 | 256 | return fcntl64 (fd, F_SETLKW, &fl); |
8fbd574e CV |
257 | } |
258 | }; | |
259 | ||
7b487ba9 CV |
260 | /* POSIX shared memory object implementation. */ |
261 | ||
262 | extern "C" int | |
263 | shm_open (const char *name, int oflag, mode_t mode) | |
264 | { | |
547ad329 CV |
265 | size_t len = strlen (name); |
266 | char shmname[ipc_names[shmem].prefix_len + len]; | |
7b487ba9 | 267 | |
547ad329 | 268 | if (!check_path (shmname, shmem, name, len)) |
7b487ba9 CV |
269 | return -1; |
270 | ||
271 | /* Check for valid flags. */ | |
272 | if (((oflag & O_ACCMODE) != O_RDONLY && (oflag & O_ACCMODE) != O_RDWR) | |
273 | || (oflag & ~(O_ACCMODE | O_CREAT | O_EXCL | O_TRUNC))) | |
274 | { | |
275 | debug_printf ("Invalid oflag 0%o", oflag); | |
276 | set_errno (EINVAL); | |
277 | return -1; | |
278 | } | |
279 | ||
e70fdfb9 | 280 | return open (shmname, oflag | O_CLOEXEC, mode & 0777); |
7b487ba9 CV |
281 | } |
282 | ||
283 | extern "C" int | |
284 | shm_unlink (const char *name) | |
285 | { | |
547ad329 CV |
286 | size_t len = strlen (name); |
287 | char shmname[ipc_names[shmem].prefix_len + len]; | |
7b487ba9 | 288 | |
547ad329 | 289 | if (!check_path (shmname, shmem, name, len)) |
7b487ba9 CV |
290 | return -1; |
291 | ||
292 | return unlink (shmname); | |
293 | } | |
294 | ||
295 | /* The POSIX message queue implementation is based on W. Richard STEVENS | |
296 | implementation, just tweaked for Cygwin. The main change is | |
297 | the usage of Windows mutexes and events instead of using the pthread | |
298 | synchronization objects. The pathname is massaged so that the | |
299 | files are created under /dev/mqueue. mq_timedsend and mq_timedreceive | |
300 | are implemented additionally. */ | |
301 | ||
7b487ba9 CV |
302 | extern "C" mqd_t |
303 | mq_open (const char *name, int oflag, ...) | |
304 | { | |
7b487ba9 | 305 | va_list ap; |
b62450cf | 306 | mode_t mode = 0; |
723f38b1 | 307 | fhandler_mqueue *fh = NULL; |
b62450cf | 308 | struct mq_attr *attr = NULL; |
7b487ba9 | 309 | |
547ad329 CV |
310 | size_t len = strlen (name); |
311 | char mqname[ipc_names[mqueue].prefix_len + len]; | |
312 | ||
313 | if (!check_path (mqname, mqueue, name, len)) | |
7b487ba9 CV |
314 | return (mqd_t) -1; |
315 | ||
3f3bd101 CV |
316 | __try |
317 | { | |
3f3bd101 CV |
318 | if (oflag & O_CREAT) |
319 | { | |
320 | va_start (ap, oflag); /* init ap to final named argument */ | |
321 | mode = va_arg (ap, mode_t) & ~S_IXUSR; | |
322 | attr = va_arg (ap, struct mq_attr *); | |
323 | va_end (ap); | |
7b487ba9 | 324 | } |
7b487ba9 | 325 | |
4fc922b2 | 326 | /* Create file descriptor for mqueue */ |
b62450cf | 327 | cygheap_fdnew fd; |
4fc922b2 | 328 | |
b62450cf | 329 | if (fd < 0) |
4fc922b2 | 330 | __leave; |
b62450cf CV |
331 | fh = (fhandler_mqueue *) build_fh_name (mqname, |
332 | PC_OPEN | PC_POSIX | |
333 | | PC_SYM_NOFOLLOW | PC_NULLEMPTY, | |
334 | NULL); | |
4fc922b2 CV |
335 | if (!fh) |
336 | __leave; | |
4fc922b2 | 337 | |
b62450cf CV |
338 | if (fh->mq_open (oflag, mode, attr)) |
339 | { | |
340 | fd = fh; | |
341 | return (mqd_t) fd; | |
342 | } | |
7b487ba9 | 343 | } |
3f3bd101 CV |
344 | __except (EFAULT) {} |
345 | __endtry | |
bce3563e | 346 | if (fh) |
b62450cf | 347 | delete fh; |
7b487ba9 CV |
348 | return (mqd_t) -1; |
349 | } | |
350 | ||
4fc922b2 CV |
351 | static struct mq_info * |
352 | get_mqinfo (cygheap_fdget &fd) | |
353 | { | |
354 | if (fd >= 0) | |
355 | { | |
356 | fhandler_mqueue *fh = fd->is_mqueue (); | |
a4e07467 | 357 | if (fh) |
4fc922b2 | 358 | return fh->mqinfo (); |
a4e07467 | 359 | set_errno (EINVAL); |
4fc922b2 CV |
360 | } |
361 | return NULL; | |
362 | } | |
363 | ||
7b487ba9 CV |
364 | extern "C" int |
365 | mq_getattr (mqd_t mqd, struct mq_attr *mqstat) | |
366 | { | |
367 | int n; | |
368 | struct mq_hdr *mqhdr; | |
61522196 | 369 | struct mq_fattr *attr; |
7b487ba9 | 370 | struct mq_info *mqinfo; |
7b44665a | 371 | |
3f3bd101 | 372 | __try |
7b487ba9 | 373 | { |
4fc922b2 CV |
374 | cygheap_fdget fd ((int) mqd, true); |
375 | mqinfo = get_mqinfo (fd); | |
3f3bd101 CV |
376 | if (mqinfo->mqi_magic != MQI_MAGIC) |
377 | { | |
378 | set_errno (EBADF); | |
379 | __leave; | |
380 | } | |
381 | mqhdr = mqinfo->mqi_hdr; | |
382 | attr = &mqhdr->mqh_attr; | |
c6d1382a | 383 | if ((n = ipc_mutex_lock (mqinfo->mqi_lock, false)) != 0) |
3f3bd101 CV |
384 | { |
385 | errno = n; | |
386 | __leave; | |
387 | } | |
388 | mqstat->mq_flags = mqinfo->mqi_flags; /* per-open */ | |
389 | mqstat->mq_maxmsg = attr->mq_maxmsg; /* remaining three per-queue */ | |
390 | mqstat->mq_msgsize = attr->mq_msgsize; | |
391 | mqstat->mq_curmsgs = attr->mq_curmsgs; | |
7b487ba9 | 392 | |
3f3bd101 CV |
393 | ipc_mutex_unlock (mqinfo->mqi_lock); |
394 | return 0; | |
395 | } | |
396 | __except (EBADF) {} | |
397 | __endtry | |
398 | return -1; | |
7b44665a | 399 | } |
7b487ba9 CV |
400 | |
401 | extern "C" int | |
402 | mq_setattr (mqd_t mqd, const struct mq_attr *mqstat, struct mq_attr *omqstat) | |
403 | { | |
404 | int n; | |
7b44665a | 405 | struct mq_hdr *mqhdr; |
61522196 | 406 | struct mq_fattr *attr; |
7b487ba9 CV |
407 | struct mq_info *mqinfo; |
408 | ||
3f3bd101 | 409 | __try |
7b487ba9 | 410 | { |
4fc922b2 CV |
411 | cygheap_fdget fd ((int) mqd, true); |
412 | mqinfo = get_mqinfo (fd); | |
3f3bd101 CV |
413 | if (mqinfo->mqi_magic != MQI_MAGIC) |
414 | { | |
415 | set_errno (EBADF); | |
416 | __leave; | |
417 | } | |
418 | mqhdr = mqinfo->mqi_hdr; | |
419 | attr = &mqhdr->mqh_attr; | |
c6d1382a | 420 | if ((n = ipc_mutex_lock (mqinfo->mqi_lock, false)) != 0) |
3f3bd101 CV |
421 | { |
422 | errno = n; | |
423 | __leave; | |
424 | } | |
7b487ba9 | 425 | |
3f3bd101 CV |
426 | if (omqstat != NULL) |
427 | { | |
428 | omqstat->mq_flags = mqinfo->mqi_flags; /* previous attributes */ | |
429 | omqstat->mq_maxmsg = attr->mq_maxmsg; | |
430 | omqstat->mq_msgsize = attr->mq_msgsize; | |
431 | omqstat->mq_curmsgs = attr->mq_curmsgs; /* and current status */ | |
432 | } | |
7b487ba9 | 433 | |
3f3bd101 CV |
434 | if (mqstat->mq_flags & O_NONBLOCK) |
435 | mqinfo->mqi_flags |= O_NONBLOCK; | |
436 | else | |
437 | mqinfo->mqi_flags &= ~O_NONBLOCK; | |
7b487ba9 | 438 | |
3f3bd101 CV |
439 | ipc_mutex_unlock (mqinfo->mqi_lock); |
440 | return 0; | |
441 | } | |
442 | __except (EBADF) {} | |
443 | __endtry | |
444 | return -1; | |
7b487ba9 CV |
445 | } |
446 | ||
447 | extern "C" int | |
448 | mq_notify (mqd_t mqd, const struct sigevent *notification) | |
449 | { | |
450 | int n; | |
451 | pid_t pid; | |
452 | struct mq_hdr *mqhdr; | |
453 | struct mq_info *mqinfo; | |
7b44665a | 454 | |
3f3bd101 | 455 | __try |
7b487ba9 | 456 | { |
4fc922b2 CV |
457 | cygheap_fdget fd ((int) mqd, true); |
458 | mqinfo = get_mqinfo (fd); | |
3f3bd101 CV |
459 | if (mqinfo->mqi_magic != MQI_MAGIC) |
460 | { | |
461 | set_errno (EBADF); | |
462 | __leave; | |
463 | } | |
464 | mqhdr = mqinfo->mqi_hdr; | |
c6d1382a | 465 | if ((n = ipc_mutex_lock (mqinfo->mqi_lock, false)) != 0) |
3f3bd101 CV |
466 | { |
467 | errno = n; | |
468 | __leave; | |
469 | } | |
7b44665a | 470 | |
3f3bd101 CV |
471 | pid = getpid (); |
472 | if (!notification) | |
7b487ba9 | 473 | { |
3f3bd101 CV |
474 | if (mqhdr->mqh_pid == pid) |
475 | mqhdr->mqh_pid = 0; /* unregister calling process */ | |
476 | } | |
477 | else | |
478 | { | |
479 | if (mqhdr->mqh_pid != 0) | |
7b487ba9 | 480 | { |
3f3bd101 CV |
481 | if (kill (mqhdr->mqh_pid, 0) != -1 || errno != ESRCH) |
482 | { | |
483 | set_errno (EBUSY); | |
484 | ipc_mutex_unlock (mqinfo->mqi_lock); | |
485 | __leave; | |
486 | } | |
7b487ba9 | 487 | } |
3f3bd101 CV |
488 | mqhdr->mqh_pid = pid; |
489 | mqhdr->mqh_event = *notification; | |
7b487ba9 | 490 | } |
3f3bd101 CV |
491 | ipc_mutex_unlock (mqinfo->mqi_lock); |
492 | return 0; | |
7b44665a | 493 | } |
3f3bd101 CV |
494 | __except (EBADF) {} |
495 | __endtry | |
496 | return -1; | |
7b44665a | 497 | } |
7b487ba9 CV |
498 | |
499 | static int | |
500 | _mq_send (mqd_t mqd, const char *ptr, size_t len, unsigned int prio, | |
501 | const struct timespec *abstime) | |
502 | { | |
503 | int n; | |
504 | long index, freeindex; | |
505 | int8_t *mptr; | |
506 | struct sigevent *sigev; | |
507 | struct mq_hdr *mqhdr; | |
61522196 | 508 | struct mq_fattr *attr; |
7b487ba9 | 509 | struct msg_hdr *msghdr, *nmsghdr, *pmsghdr; |
3f3bd101 CV |
510 | struct mq_info *mqinfo = NULL; |
511 | bool ipc_mutex_locked = false; | |
512 | int ret = -1; | |
7b487ba9 | 513 | |
74f9ac5b CV |
514 | pthread_testcancel (); |
515 | ||
3f3bd101 | 516 | __try |
7b487ba9 | 517 | { |
4fc922b2 CV |
518 | cygheap_fdget fd ((int) mqd); |
519 | mqinfo = get_mqinfo (fd); | |
3f3bd101 CV |
520 | if (mqinfo->mqi_magic != MQI_MAGIC) |
521 | { | |
522 | set_errno (EBADF); | |
523 | __leave; | |
524 | } | |
4f89f24f | 525 | if (prio >= MQ_PRIO_MAX) |
3f3bd101 CV |
526 | { |
527 | set_errno (EINVAL); | |
528 | __leave; | |
529 | } | |
7b487ba9 | 530 | |
3f3bd101 CV |
531 | mqhdr = mqinfo->mqi_hdr; /* struct pointer */ |
532 | mptr = (int8_t *) mqhdr; /* byte pointer */ | |
533 | attr = &mqhdr->mqh_attr; | |
c6d1382a | 534 | if ((n = ipc_mutex_lock (mqinfo->mqi_lock, true)) != 0) |
7b487ba9 | 535 | { |
3f3bd101 CV |
536 | errno = n; |
537 | __leave; | |
7b487ba9 | 538 | } |
3f3bd101 CV |
539 | ipc_mutex_locked = true; |
540 | if (len > (size_t) attr->mq_msgsize) | |
7b487ba9 | 541 | { |
3f3bd101 CV |
542 | set_errno (EMSGSIZE); |
543 | __leave; | |
7b487ba9 | 544 | } |
3f3bd101 | 545 | if (attr->mq_curmsgs == 0) |
b994b837 | 546 | { |
3f3bd101 | 547 | if (mqhdr->mqh_pid != 0 && mqhdr->mqh_nwait == 0) |
b994b837 | 548 | { |
3f3bd101 CV |
549 | sigev = &mqhdr->mqh_event; |
550 | if (sigev->sigev_notify == SIGEV_SIGNAL) | |
551 | sigqueue (mqhdr->mqh_pid, sigev->sigev_signo, | |
552 | sigev->sigev_value); | |
553 | mqhdr->mqh_pid = 0; /* unregister */ | |
554 | } | |
555 | } | |
556 | else if (attr->mq_curmsgs >= attr->mq_maxmsg) | |
557 | { | |
558 | /* Queue is full */ | |
559 | if (mqinfo->mqi_flags & O_NONBLOCK) | |
560 | { | |
561 | set_errno (EAGAIN); | |
562 | __leave; | |
563 | } | |
564 | /* Wait for room for one message on the queue */ | |
565 | while (attr->mq_curmsgs >= attr->mq_maxmsg) | |
566 | { | |
567 | int ret = ipc_cond_timedwait (mqinfo->mqi_waitsend, | |
568 | mqinfo->mqi_lock, abstime); | |
569 | if (ret != 0) | |
570 | { | |
571 | set_errno (ret); | |
572 | __leave; | |
573 | } | |
b994b837 CV |
574 | } |
575 | } | |
7b487ba9 | 576 | |
3f3bd101 CV |
577 | /* nmsghdr will point to new message */ |
578 | if ((freeindex = mqhdr->mqh_free) == 0) | |
579 | api_fatal ("mq_send: curmsgs = %ld; free = 0", attr->mq_curmsgs); | |
7b487ba9 | 580 | |
3f3bd101 CV |
581 | nmsghdr = (struct msg_hdr *) &mptr[freeindex]; |
582 | nmsghdr->msg_prio = prio; | |
583 | nmsghdr->msg_len = len; | |
584 | memcpy (nmsghdr + 1, ptr, len); /* copy message from caller */ | |
585 | mqhdr->mqh_free = nmsghdr->msg_next; /* new freelist head */ | |
7b487ba9 | 586 | |
3f3bd101 CV |
587 | /* Find right place for message in linked list */ |
588 | index = mqhdr->mqh_head; | |
589 | pmsghdr = (struct msg_hdr *) &(mqhdr->mqh_head); | |
590 | while (index) | |
7b487ba9 | 591 | { |
3f3bd101 CV |
592 | msghdr = (struct msg_hdr *) &mptr[index]; |
593 | if (prio > msghdr->msg_prio) | |
594 | { | |
595 | nmsghdr->msg_next = index; | |
596 | pmsghdr->msg_next = freeindex; | |
597 | break; | |
598 | } | |
599 | index = msghdr->msg_next; | |
600 | pmsghdr = msghdr; | |
601 | } | |
602 | if (index == 0) | |
603 | { | |
604 | /* Queue was empty or new goes at end of list */ | |
7b487ba9 | 605 | pmsghdr->msg_next = freeindex; |
3f3bd101 | 606 | nmsghdr->msg_next = 0; |
7b487ba9 | 607 | } |
3f3bd101 CV |
608 | /* Wake up anyone blocked in mq_receive waiting for a message */ |
609 | if (attr->mq_curmsgs == 0) | |
610 | ipc_cond_signal (mqinfo->mqi_waitrecv); | |
611 | attr->mq_curmsgs++; | |
7b487ba9 | 612 | |
3f3bd101 CV |
613 | ret = 0; |
614 | } | |
615 | __except (EBADF) {} | |
616 | __endtry | |
617 | if (ipc_mutex_locked) | |
618 | ipc_mutex_unlock (mqinfo->mqi_lock); | |
619 | return ret; | |
7b487ba9 CV |
620 | } |
621 | ||
622 | extern "C" int | |
623 | mq_send (mqd_t mqd, const char *ptr, size_t len, unsigned int prio) | |
624 | { | |
625 | return _mq_send (mqd, ptr, len, prio, NULL); | |
626 | } | |
627 | ||
628 | extern "C" int | |
629 | mq_timedsend (mqd_t mqd, const char *ptr, size_t len, unsigned int prio, | |
630 | const struct timespec *abstime) | |
631 | { | |
632 | return _mq_send (mqd, ptr, len, prio, abstime); | |
633 | } | |
634 | ||
635 | static ssize_t | |
636 | _mq_receive (mqd_t mqd, char *ptr, size_t maxlen, unsigned int *priop, | |
637 | const struct timespec *abstime) | |
638 | { | |
639 | int n; | |
640 | long index; | |
641 | int8_t *mptr; | |
3f3bd101 | 642 | ssize_t len = -1; |
7b44665a | 643 | struct mq_hdr *mqhdr; |
61522196 | 644 | struct mq_fattr *attr; |
7b487ba9 | 645 | struct msg_hdr *msghdr; |
4fc922b2 | 646 | struct mq_info *mqinfo; |
3f3bd101 | 647 | bool ipc_mutex_locked = false; |
7b487ba9 | 648 | |
74f9ac5b CV |
649 | pthread_testcancel (); |
650 | ||
3f3bd101 | 651 | __try |
7b487ba9 | 652 | { |
4fc922b2 CV |
653 | cygheap_fdget fd ((int) mqd); |
654 | mqinfo = get_mqinfo (fd); | |
3f3bd101 CV |
655 | if (mqinfo->mqi_magic != MQI_MAGIC) |
656 | { | |
657 | set_errno (EBADF); | |
658 | __leave; | |
659 | } | |
660 | mqhdr = mqinfo->mqi_hdr; /* struct pointer */ | |
661 | mptr = (int8_t *) mqhdr; /* byte pointer */ | |
662 | attr = &mqhdr->mqh_attr; | |
c6d1382a | 663 | if ((n = ipc_mutex_lock (mqinfo->mqi_lock, true)) != 0) |
3f3bd101 CV |
664 | { |
665 | errno = n; | |
666 | __leave; | |
667 | } | |
668 | ipc_mutex_locked = true; | |
669 | if (maxlen < (size_t) attr->mq_msgsize) | |
7b487ba9 | 670 | { |
3f3bd101 CV |
671 | set_errno (EMSGSIZE); |
672 | __leave; | |
7b487ba9 | 673 | } |
3f3bd101 | 674 | if (attr->mq_curmsgs == 0) /* queue is empty */ |
b994b837 | 675 | { |
3f3bd101 | 676 | if (mqinfo->mqi_flags & O_NONBLOCK) |
b994b837 | 677 | { |
3f3bd101 CV |
678 | set_errno (EAGAIN); |
679 | __leave; | |
b994b837 | 680 | } |
3f3bd101 CV |
681 | /* Wait for a message to be placed onto queue */ |
682 | mqhdr->mqh_nwait++; | |
683 | while (attr->mq_curmsgs == 0) | |
684 | { | |
685 | int ret = ipc_cond_timedwait (mqinfo->mqi_waitrecv, | |
686 | mqinfo->mqi_lock, abstime); | |
687 | if (ret != 0) | |
688 | { | |
689 | set_errno (ret); | |
690 | __leave; | |
691 | } | |
692 | } | |
693 | mqhdr->mqh_nwait--; | |
b994b837 | 694 | } |
7b487ba9 | 695 | |
3f3bd101 CV |
696 | if ((index = mqhdr->mqh_head) == 0) |
697 | api_fatal ("mq_receive: curmsgs = %ld; head = 0", attr->mq_curmsgs); | |
7b487ba9 | 698 | |
3f3bd101 CV |
699 | msghdr = (struct msg_hdr *) &mptr[index]; |
700 | mqhdr->mqh_head = msghdr->msg_next; /* new head of list */ | |
701 | len = msghdr->msg_len; | |
702 | memcpy(ptr, msghdr + 1, len); /* copy the message itself */ | |
703 | if (priop != NULL) | |
704 | *priop = msghdr->msg_prio; | |
705 | ||
706 | /* Just-read message goes to front of free list */ | |
707 | msghdr->msg_next = mqhdr->mqh_free; | |
708 | mqhdr->mqh_free = index; | |
7b487ba9 | 709 | |
3f3bd101 CV |
710 | /* Wake up anyone blocked in mq_send waiting for room */ |
711 | if (attr->mq_curmsgs == attr->mq_maxmsg) | |
712 | ipc_cond_signal (mqinfo->mqi_waitsend); | |
713 | attr->mq_curmsgs--; | |
3f3bd101 CV |
714 | } |
715 | __except (EBADF) {} | |
716 | __endtry | |
717 | if (ipc_mutex_locked) | |
718 | ipc_mutex_unlock (mqinfo->mqi_lock); | |
7b487ba9 | 719 | return len; |
7b487ba9 CV |
720 | } |
721 | ||
722 | extern "C" ssize_t | |
723 | mq_receive (mqd_t mqd, char *ptr, size_t maxlen, unsigned int *priop) | |
724 | { | |
725 | return _mq_receive (mqd, ptr, maxlen, priop, NULL); | |
726 | } | |
727 | ||
728 | extern "C" ssize_t | |
729 | mq_timedreceive (mqd_t mqd, char *ptr, size_t maxlen, unsigned int *priop, | |
730 | const struct timespec *abstime) | |
731 | { | |
732 | return _mq_receive (mqd, ptr, maxlen, priop, abstime); | |
733 | } | |
734 | ||
735 | extern "C" int | |
736 | mq_close (mqd_t mqd) | |
737 | { | |
3f3bd101 | 738 | __try |
7b487ba9 | 739 | { |
4fc922b2 | 740 | cygheap_fdget fd ((int) mqd, true); |
2cc914a3 | 741 | if (!fd->is_mqueue ()) |
3f3bd101 CV |
742 | { |
743 | set_errno (EBADF); | |
744 | __leave; | |
745 | } | |
7b487ba9 | 746 | |
3f3bd101 CV |
747 | if (mq_notify (mqd, NULL)) /* unregister calling process */ |
748 | __leave; | |
7b487ba9 | 749 | |
4fc922b2 CV |
750 | fd->isclosed (true); |
751 | fd->close (); | |
752 | fd.release (); | |
3f3bd101 CV |
753 | return 0; |
754 | } | |
755 | __except (EBADF) {} | |
756 | __endtry | |
757 | return -1; | |
7b487ba9 CV |
758 | } |
759 | ||
760 | extern "C" int | |
761 | mq_unlink (const char *name) | |
762 | { | |
547ad329 CV |
763 | size_t len = strlen (name); |
764 | char mqname[ipc_names[mqueue].prefix_len + len]; | |
7b487ba9 | 765 | |
547ad329 | 766 | if (!check_path (mqname, mqueue, name, len)) |
7b487ba9 CV |
767 | return -1; |
768 | if (unlink (mqname) == -1) | |
769 | return -1; | |
770 | return 0; | |
771 | } | |
772 | ||
8fbd574e CV |
773 | /* POSIX named semaphore implementation. Loosely based on Richard W. STEPHENS |
774 | implementation as far as sem_open is concerned, but under the hood using | |
775 | the already existing semaphore class in thread.cc. Using a file backed | |
776 | solution allows to implement kernel persistent named semaphores. */ | |
777 | ||
b62450cf CV |
778 | #define MAX_TRIES 10 /* for waiting for initialization */ |
779 | ||
8fbd574e CV |
780 | struct sem_finfo |
781 | { | |
782 | unsigned int value; | |
783 | unsigned long long hash; | |
784 | LUID luid; | |
785 | }; | |
786 | ||
787 | extern "C" sem_t * | |
788 | sem_open (const char *name, int oflag, ...) | |
789 | { | |
3f3bd101 | 790 | int i, fd = -1, created = 0; |
8fbd574e CV |
791 | va_list ap; |
792 | mode_t mode = 0; | |
793 | unsigned int value = 0; | |
61522196 | 794 | struct stat statbuff; |
8fbd574e CV |
795 | sem_t *sem = SEM_FAILED; |
796 | sem_finfo sf; | |
8fbd574e CV |
797 | bool wasopen = false; |
798 | ipc_flock file; | |
799 | ||
547ad329 CV |
800 | size_t len = strlen (name); |
801 | char semname[ipc_names[semaphore].prefix_len + len]; | |
802 | ||
803 | if (!check_path (semname, semaphore, name, len)) | |
8fbd574e CV |
804 | return SEM_FAILED; |
805 | ||
3f3bd101 | 806 | __try |
8fbd574e | 807 | { |
3f3bd101 CV |
808 | oflag &= (O_CREAT | O_EXCL); |
809 | ||
810 | again: | |
811 | if (oflag & O_CREAT) | |
7b44665a | 812 | { |
3f3bd101 CV |
813 | va_start (ap, oflag); /* init ap to final named argument */ |
814 | mode = va_arg (ap, mode_t) & ~S_IXUSR; | |
815 | value = va_arg (ap, unsigned int); | |
816 | va_end (ap); | |
817 | ||
818 | /* Open and specify O_EXCL and user-execute */ | |
819 | fd = open (semname, oflag | O_EXCL | O_RDWR | O_CLOEXEC, | |
820 | mode | S_IXUSR); | |
821 | if (fd < 0) | |
822 | { | |
823 | if (errno == EEXIST && (oflag & O_EXCL) == 0) | |
824 | goto exists; /* already exists, OK */ | |
825 | return SEM_FAILED; | |
826 | } | |
827 | created = 1; | |
828 | /* First one to create the file initializes it. */ | |
829 | NtAllocateLocallyUniqueId (&sf.luid); | |
830 | sf.value = value; | |
831 | sf.hash = hash_path_name (0, semname); | |
832 | if (write (fd, &sf, sizeof sf) != sizeof sf) | |
833 | __leave; | |
834 | sem = semaphore::open (sf.hash, sf.luid, fd, oflag, mode, value, | |
835 | wasopen); | |
836 | if (sem == SEM_FAILED) | |
837 | __leave; | |
838 | /* Initialization complete, turn off user-execute bit */ | |
839 | if (fchmod (fd, mode) == -1) | |
840 | __leave; | |
841 | /* Don't close (fd); */ | |
842 | return sem; | |
8fbd574e | 843 | } |
8fbd574e | 844 | |
3f3bd101 CV |
845 | exists: |
846 | /* Open the file and fetch the semaphore name. */ | |
847 | if ((fd = open (semname, O_RDWR | O_CLOEXEC)) < 0) | |
8fbd574e CV |
848 | { |
849 | if (errno == ENOENT && (oflag & O_CREAT)) | |
3f3bd101 CV |
850 | goto again; |
851 | __leave; | |
852 | } | |
853 | /* Make certain initialization is complete */ | |
854 | for (i = 0; i < MAX_TRIES; i++) | |
855 | { | |
856 | if (stat64 (semname, &statbuff) == -1) | |
8fbd574e | 857 | { |
3f3bd101 CV |
858 | if (errno == ENOENT && (oflag & O_CREAT)) |
859 | { | |
860 | close (fd); | |
861 | fd = -1; | |
862 | goto again; | |
863 | } | |
864 | __leave; | |
8fbd574e | 865 | } |
3f3bd101 CV |
866 | if ((statbuff.st_mode & S_IXUSR) == 0) |
867 | break; | |
868 | sleep (1); | |
8fbd574e | 869 | } |
3f3bd101 CV |
870 | if (i == MAX_TRIES) |
871 | { | |
872 | set_errno (ETIMEDOUT); | |
873 | __leave; | |
874 | } | |
875 | if (file.lock (fd, sizeof sf)) | |
876 | __leave; | |
877 | if (read (fd, &sf, sizeof sf) != sizeof sf) | |
878 | __leave; | |
879 | sem = semaphore::open (sf.hash, sf.luid, fd, oflag, mode, sf.value, | |
880 | wasopen); | |
881 | file.unlock (fd); | |
882 | if (sem == SEM_FAILED) | |
883 | __leave; | |
884 | /* If wasopen is set, the semaphore was already opened and we already have | |
885 | an open file descriptor pointing to the file. This means, we have to | |
886 | close the file descriptor created in this call. It won't be stored | |
887 | anywhere anyway. */ | |
888 | if (wasopen) | |
889 | close (fd); | |
890 | return sem; | |
8fbd574e | 891 | } |
3f3bd101 CV |
892 | __except (EFAULT) {} |
893 | __endtry | |
8fbd574e CV |
894 | /* Don't let following function calls change errno */ |
895 | save_errno save; | |
896 | ||
3f3bd101 CV |
897 | if (fd >= 0) |
898 | file.unlock (fd); | |
8fbd574e CV |
899 | if (created) |
900 | unlink (semname); | |
901 | if (sem != SEM_FAILED) | |
902 | semaphore::close (sem); | |
599d462d CV |
903 | if (fd >= 0) |
904 | close (fd); | |
8fbd574e CV |
905 | return SEM_FAILED; |
906 | } | |
907 | ||
b62450cf CV |
908 | extern "C" off_t lseek64 (int, off_t, int); |
909 | ||
8fbd574e CV |
910 | int |
911 | _sem_close (sem_t *sem, bool do_close) | |
912 | { | |
913 | sem_finfo sf; | |
914 | int fd, ret = -1; | |
915 | ipc_flock file; | |
916 | ||
917 | if (semaphore::getinternal (sem, &fd, &sf.hash, &sf.luid, &sf.value) == -1) | |
918 | return -1; | |
919 | if (!file.lock (fd, sizeof sf) | |
61522196 | 920 | && lseek64 (fd, 0LL, SEEK_SET) != (off_t) -1 |
8fbd574e CV |
921 | && write (fd, &sf, sizeof sf) == sizeof sf) |
922 | ret = do_close ? semaphore::close (sem) : 0; | |
923 | ||
924 | /* Don't let following function calls change errno */ | |
925 | save_errno save; | |
926 | file.unlock (fd); | |
927 | close (fd); | |
928 | ||
929 | return ret; | |
930 | } | |
931 | ||
932 | extern "C" int | |
933 | sem_close (sem_t *sem) | |
934 | { | |
935 | return _sem_close (sem, true); | |
936 | } | |
937 | ||
938 | extern "C" int | |
939 | sem_unlink (const char *name) | |
940 | { | |
547ad329 CV |
941 | size_t len = strlen (name); |
942 | char semname[ipc_names[semaphore].prefix_len + len]; | |
8fbd574e | 943 | |
547ad329 | 944 | if (!check_path (semname, semaphore, name, len)) |
8fbd574e CV |
945 | return -1; |
946 | if (unlink (semname) == -1) | |
947 | return -1; | |
948 | return 0; | |
949 | } |