]>
Commit | Line | Data |
---|---|---|
7b487ba9 CV |
1 | /* posix_ipc.cc: POSIX IPC API for Cygwin. |
2 | ||
3 | Copyright 2007 Red Hat, Inc. | |
4 | ||
5 | This file is part of Cygwin. | |
6 | ||
7 | This software is a copyrighted work licensed under the terms of the | |
8 | Cygwin license. Please consult the file "CYGWIN_LICENSE" for | |
9 | details. */ | |
10 | ||
7b487ba9 | 11 | #include "winsup.h" |
8fbd574e | 12 | #include "thread.h" |
7b487ba9 | 13 | #include "path.h" |
7b487ba9 | 14 | #include "cygtls.h" |
e6fbf13e CV |
15 | #include "fhandler.h" |
16 | #include "dtable.h" | |
17 | #include "cygheap.h" | |
7b487ba9 | 18 | #include "sigproc.h" |
abbde487 | 19 | #include "ntdll.h" |
7b487ba9 CV |
20 | #include <sys/mman.h> |
21 | #include <sys/param.h> | |
7b487ba9 | 22 | #include <stdlib.h> |
7b487ba9 | 23 | #include <unistd.h> |
7b487ba9 | 24 | #include <mqueue.h> |
8fbd574e | 25 | #include <semaphore.h> |
7b487ba9 | 26 | |
547ad329 CV |
27 | /* The prefix_len is the length of the path prefix ncluding trailing "/" |
28 | (or "/sem." for semaphores) as well as the trailing NUL. */ | |
7b487ba9 CV |
29 | struct |
30 | { | |
31 | const char *prefix; | |
547ad329 | 32 | const size_t prefix_len; |
7b487ba9 CV |
33 | const char *description; |
34 | } ipc_names[] = { | |
547ad329 CV |
35 | { "/dev/shm", 10, "POSIX shared memory object" }, |
36 | { "/dev/mqueue", 13, "POSIX message queue" }, | |
37 | { "/dev/shm", 14, "POSIX semaphore" } | |
7b487ba9 CV |
38 | }; |
39 | ||
40 | enum ipc_type_t | |
41 | { | |
42 | shmem, | |
43 | mqueue, | |
8fbd574e | 44 | semaphore |
7b487ba9 CV |
45 | }; |
46 | ||
47 | static bool | |
547ad329 | 48 | check_path (char *res_name, ipc_type_t type, const char *name, size_t len) |
7b487ba9 CV |
49 | { |
50 | /* Note that we require the existance of the apprpriate /dev subdirectories | |
51 | for POSIX IPC object support, similar to Linux (which supports the | |
52 | directories, but doesn't require to mount them). We don't create | |
53 | these directory here, that's the task of the installer. But we check | |
54 | for existance and give ample warning. */ | |
55 | path_conv path (ipc_names[type].prefix, PC_SYM_NOFOLLOW); | |
56 | if (path.error || !path.exists () || !path.isdir ()) | |
57 | { | |
58 | small_printf ( | |
59 | "Warning: '%s' does not exists or is not a directory.\n\n" | |
60 | "%ss require the existance of this directory.\n" | |
61 | "Create the directory '%s' and set the permissions to 01777.\n" | |
62 | "For instance on the command line: mkdir -m 01777 %s\n", | |
63 | ipc_names[type].prefix, ipc_names[type].description, | |
64 | ipc_names[type].prefix, ipc_names[type].prefix); | |
65 | set_errno (EINVAL); | |
66 | return false; | |
67 | } | |
68 | /* Name must start with a single slash. */ | |
8fbd574e | 69 | if (!name || name[0] != '/' || name[1] == '/' || !name[1]) |
7b487ba9 CV |
70 | { |
71 | debug_printf ("Invalid %s name '%s'", ipc_names[type].description, name); | |
72 | set_errno (EINVAL); | |
73 | return false; | |
74 | } | |
547ad329 | 75 | if (len > PATH_MAX - ipc_names[type].prefix_len) |
7b487ba9 CV |
76 | { |
77 | debug_printf ("%s name '%s' too long", ipc_names[type].description, name); | |
78 | set_errno (ENAMETOOLONG); | |
79 | return false; | |
80 | } | |
8fbd574e CV |
81 | __small_sprintf (res_name, "%s/%s%s", ipc_names[type].prefix, |
82 | type == semaphore ? "sem." : "", | |
83 | name + 1); | |
7b487ba9 CV |
84 | return true; |
85 | } | |
86 | ||
87 | static int | |
88 | ipc_mutex_init (HANDLE *pmtx, const char *name) | |
89 | { | |
547ad329 | 90 | char buf[MAX_PATH]; |
abbde487 CV |
91 | SECURITY_ATTRIBUTES sa = sec_none; |
92 | ||
93 | __small_sprintf (buf, "mqueue/mtx_%W", name); | |
94 | sa.lpSecurityDescriptor = everyone_sd (CYG_MUTANT_ACCESS); | |
95 | *pmtx = CreateMutex (&sa, FALSE, buf); | |
7b487ba9 | 96 | if (!*pmtx) |
abbde487 | 97 | debug_printf ("CreateMutex: %E"); |
7b487ba9 CV |
98 | return *pmtx ? 0 : geterrno_from_win_error (); |
99 | } | |
100 | ||
101 | static int | |
102 | ipc_mutex_lock (HANDLE mtx) | |
103 | { | |
104 | HANDLE h[2] = { mtx, signal_arrived }; | |
105 | ||
106 | switch (WaitForMultipleObjects (2, h, FALSE, INFINITE)) | |
7b44665a | 107 | { |
7b487ba9 CV |
108 | case WAIT_OBJECT_0: |
109 | case WAIT_ABANDONED_0: | |
110 | return 0; | |
111 | case WAIT_OBJECT_0 + 1: | |
112 | set_errno (EINTR); | |
113 | return 1; | |
114 | default: | |
115 | break; | |
7b44665a | 116 | } |
7b487ba9 CV |
117 | return geterrno_from_win_error (); |
118 | } | |
119 | ||
120 | static inline int | |
121 | ipc_mutex_unlock (HANDLE mtx) | |
122 | { | |
123 | return ReleaseMutex (mtx) ? 0 : geterrno_from_win_error (); | |
124 | } | |
125 | ||
126 | static inline int | |
127 | ipc_mutex_close (HANDLE mtx) | |
128 | { | |
129 | return CloseHandle (mtx) ? 0 : geterrno_from_win_error (); | |
130 | } | |
131 | ||
132 | static int | |
133 | ipc_cond_init (HANDLE *pevt, const char *name) | |
134 | { | |
547ad329 | 135 | char buf[MAX_PATH]; |
abbde487 CV |
136 | SECURITY_ATTRIBUTES sa = sec_none; |
137 | ||
138 | __small_sprintf (buf, "mqueue/evt_%W", name); | |
139 | sa.lpSecurityDescriptor = everyone_sd (CYG_EVENT_ACCESS); | |
140 | *pevt = CreateEvent (&sa, TRUE, FALSE, buf); | |
7b487ba9 | 141 | if (!*pevt) |
abbde487 | 142 | debug_printf ("CreateEvent: %E"); |
7b487ba9 CV |
143 | return *pevt ? 0 : geterrno_from_win_error (); |
144 | } | |
145 | ||
146 | static int | |
147 | ipc_cond_timedwait (HANDLE evt, HANDLE mtx, const struct timespec *abstime) | |
148 | { | |
149 | struct timeval tv; | |
150 | DWORD timeout; | |
151 | HANDLE h[2] = { mtx, evt }; | |
152 | ||
153 | if (!abstime) | |
154 | timeout = INFINITE; | |
155 | else if (abstime->tv_sec < 0 | |
156 | || abstime->tv_nsec < 0 | |
157 | || abstime->tv_nsec > 999999999) | |
158 | return EINVAL; | |
159 | else | |
160 | { | |
161 | gettimeofday (&tv, NULL); | |
162 | /* Check for immediate timeout. */ | |
163 | if (tv.tv_sec > abstime->tv_sec | |
164 | || (tv.tv_sec == abstime->tv_sec | |
165 | && tv.tv_usec > abstime->tv_nsec / 1000)) | |
166 | return ETIMEDOUT; | |
167 | timeout = (abstime->tv_sec - tv.tv_sec) * 1000; | |
168 | timeout += (abstime->tv_nsec / 1000 - tv.tv_usec) / 1000; | |
169 | } | |
170 | if (ipc_mutex_unlock (mtx)) | |
171 | return -1; | |
172 | switch (WaitForMultipleObjects (2, h, TRUE, timeout)) | |
7b44665a | 173 | { |
7b487ba9 CV |
174 | case WAIT_OBJECT_0: |
175 | case WAIT_ABANDONED_0: | |
176 | ResetEvent (evt); | |
177 | return 0; | |
178 | case WAIT_TIMEOUT: | |
179 | ipc_mutex_lock (mtx); | |
180 | return ETIMEDOUT; | |
181 | default: | |
182 | break; | |
7b44665a | 183 | } |
7b487ba9 CV |
184 | return geterrno_from_win_error (); |
185 | } | |
186 | ||
187 | static inline int | |
188 | ipc_cond_signal (HANDLE evt) | |
189 | { | |
190 | return SetEvent (evt) ? 0 : geterrno_from_win_error (); | |
191 | } | |
192 | ||
193 | static inline int | |
194 | ipc_cond_close (HANDLE evt) | |
195 | { | |
196 | return CloseHandle (evt) ? 0 : geterrno_from_win_error (); | |
197 | } | |
198 | ||
8fbd574e CV |
199 | class ipc_flock |
200 | { | |
201 | struct __flock64 fl; | |
202 | ||
203 | public: | |
204 | ipc_flock () { memset (&fl, 0, sizeof fl); } | |
205 | ||
206 | int lock (int fd, size_t size) | |
207 | { | |
208 | fl.l_type = F_WRLCK; | |
209 | fl.l_whence = SEEK_SET; | |
210 | fl.l_start = 0; | |
211 | fl.l_len = size; | |
fabfb1a1 | 212 | return fcntl64 (fd, F_SETLKW, &fl); |
8fbd574e CV |
213 | } |
214 | int unlock (int fd) | |
215 | { | |
216 | if (!fl.l_len) | |
217 | return 0; | |
218 | fl.l_type = F_UNLCK; | |
fabfb1a1 | 219 | return fcntl64 (fd, F_SETLKW, &fl); |
8fbd574e CV |
220 | } |
221 | }; | |
222 | ||
7b487ba9 CV |
223 | /* POSIX shared memory object implementation. */ |
224 | ||
225 | extern "C" int | |
226 | shm_open (const char *name, int oflag, mode_t mode) | |
227 | { | |
547ad329 CV |
228 | size_t len = strlen (name); |
229 | char shmname[ipc_names[shmem].prefix_len + len]; | |
7b487ba9 | 230 | |
547ad329 | 231 | if (!check_path (shmname, shmem, name, len)) |
7b487ba9 CV |
232 | return -1; |
233 | ||
234 | /* Check for valid flags. */ | |
235 | if (((oflag & O_ACCMODE) != O_RDONLY && (oflag & O_ACCMODE) != O_RDWR) | |
236 | || (oflag & ~(O_ACCMODE | O_CREAT | O_EXCL | O_TRUNC))) | |
237 | { | |
238 | debug_printf ("Invalid oflag 0%o", oflag); | |
239 | set_errno (EINVAL); | |
240 | return -1; | |
241 | } | |
242 | ||
243 | return open (shmname, oflag, mode & 0777); | |
244 | } | |
245 | ||
246 | extern "C" int | |
247 | shm_unlink (const char *name) | |
248 | { | |
547ad329 CV |
249 | size_t len = strlen (name); |
250 | char shmname[ipc_names[shmem].prefix_len + len]; | |
7b487ba9 | 251 | |
547ad329 | 252 | if (!check_path (shmname, shmem, name, len)) |
7b487ba9 CV |
253 | return -1; |
254 | ||
255 | return unlink (shmname); | |
256 | } | |
257 | ||
258 | /* The POSIX message queue implementation is based on W. Richard STEVENS | |
259 | implementation, just tweaked for Cygwin. The main change is | |
260 | the usage of Windows mutexes and events instead of using the pthread | |
261 | synchronization objects. The pathname is massaged so that the | |
262 | files are created under /dev/mqueue. mq_timedsend and mq_timedreceive | |
263 | are implemented additionally. */ | |
264 | ||
265 | struct mq_hdr | |
266 | { | |
93162be5 CV |
267 | struct mq_attr mqh_attr; /* the queue's attributes */ |
268 | long mqh_head; /* index of first message */ | |
269 | long mqh_free; /* index of first free message */ | |
270 | long mqh_nwait; /* #threads blocked in mq_receive() */ | |
271 | pid_t mqh_pid; /* nonzero PID if mqh_event set */ | |
8fbd574e | 272 | char mqh_uname[36]; /* unique name used to identify synchronization |
7b44665a | 273 | objects connected to this queue */ |
93162be5 | 274 | struct sigevent mqh_event; /* for mq_notify() */ |
7b487ba9 CV |
275 | }; |
276 | ||
277 | struct msg_hdr | |
278 | { | |
93162be5 CV |
279 | long msg_next; /* index of next on linked list */ |
280 | ssize_t msg_len; /* actual length */ | |
281 | unsigned int msg_prio; /* priority */ | |
7b487ba9 CV |
282 | }; |
283 | ||
284 | struct mq_info | |
285 | { | |
93162be5 CV |
286 | struct mq_hdr *mqi_hdr; /* start of mmap'ed region */ |
287 | unsigned long mqi_magic; /* magic number if open */ | |
288 | int mqi_flags; /* flags for this process */ | |
289 | HANDLE mqi_lock; /* mutex lock */ | |
290 | HANDLE mqi_wait; /* and condition variable */ | |
7b487ba9 CV |
291 | }; |
292 | ||
293 | #define MQI_MAGIC 0x98765432UL | |
294 | ||
295 | #define MSGSIZE(i) roundup((i), sizeof(long)) | |
296 | ||
297 | #define MAX_TRIES 10 /* for waiting for initialization */ | |
298 | ||
299 | struct mq_attr defattr = { 0, 10, 8192, 0 }; /* Linux defaults. */ | |
300 | ||
301 | extern "C" _off64_t lseek64 (int, _off64_t, int); | |
302 | extern "C" void *mmap64 (void *, size_t, int, int, int, _off64_t); | |
303 | ||
304 | extern "C" mqd_t | |
305 | mq_open (const char *name, int oflag, ...) | |
306 | { | |
307 | int i, fd, nonblock, created; | |
308 | long msgsize, index; | |
eb8a6636 | 309 | _off64_t filesize = 0; |
7b487ba9 CV |
310 | va_list ap; |
311 | mode_t mode; | |
312 | int8_t *mptr; | |
313 | struct __stat64 statbuff; | |
314 | struct mq_hdr *mqhdr; | |
315 | struct msg_hdr *msghdr; | |
316 | struct mq_attr *attr; | |
317 | struct mq_info *mqinfo; | |
8fbd574e | 318 | LUID luid; |
7b487ba9 | 319 | |
547ad329 CV |
320 | size_t len = strlen (name); |
321 | char mqname[ipc_names[mqueue].prefix_len + len]; | |
322 | ||
323 | if (!check_path (mqname, mqueue, name, len)) | |
7b487ba9 CV |
324 | return (mqd_t) -1; |
325 | ||
326 | myfault efault; | |
327 | if (efault.faulted (EFAULT)) | |
8fbd574e | 328 | return (mqd_t) -1; |
7b487ba9 | 329 | |
8fbd574e | 330 | oflag &= (O_CREAT | O_EXCL | O_NONBLOCK); |
7b487ba9 CV |
331 | created = 0; |
332 | nonblock = oflag & O_NONBLOCK; | |
333 | oflag &= ~O_NONBLOCK; | |
334 | mptr = (int8_t *) MAP_FAILED; | |
335 | mqinfo = NULL; | |
336 | ||
337 | again: | |
338 | if (oflag & O_CREAT) | |
339 | { | |
340 | va_start (ap, oflag); /* init ap to final named argument */ | |
341 | mode = va_arg (ap, mode_t) & ~S_IXUSR; | |
342 | attr = va_arg (ap, struct mq_attr *); | |
343 | va_end (ap); | |
344 | ||
345 | /* Open and specify O_EXCL and user-execute */ | |
346 | fd = open (mqname, oflag | O_EXCL | O_RDWR, mode | S_IXUSR); | |
347 | if (fd < 0) | |
7b44665a | 348 | { |
7b487ba9 CV |
349 | if (errno == EEXIST && (oflag & O_EXCL) == 0) |
350 | goto exists; /* already exists, OK */ | |
351 | return (mqd_t) -1; | |
352 | } | |
353 | created = 1; | |
354 | /* First one to create the file initializes it */ | |
355 | if (attr == NULL) | |
356 | attr = &defattr; | |
357 | else if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0) | |
358 | { | |
359 | set_errno (EINVAL); | |
360 | goto err; | |
361 | } | |
362 | /* Calculate and set the file size */ | |
363 | msgsize = MSGSIZE (attr->mq_msgsize); | |
364 | filesize = sizeof (struct mq_hdr) | |
7b44665a | 365 | + (attr->mq_maxmsg * (sizeof (struct msg_hdr) + msgsize)); |
7b487ba9 CV |
366 | if (lseek64 (fd, filesize - 1, SEEK_SET) == -1) |
367 | goto err; | |
368 | if (write (fd, "", 1) == -1) | |
369 | goto err; | |
370 | ||
371 | /* Memory map the file */ | |
372 | mptr = (int8_t *) mmap64 (NULL, (size_t) filesize, PROT_READ | PROT_WRITE, | |
373 | MAP_SHARED, fd, 0); | |
374 | if (mptr == (int8_t *) MAP_FAILED) | |
375 | goto err; | |
376 | ||
377 | /* Allocate one mq_info{} for the queue */ | |
378 | if (!(mqinfo = (struct mq_info *) malloc (sizeof (struct mq_info)))) | |
379 | goto err; | |
380 | mqinfo->mqi_hdr = mqhdr = (struct mq_hdr *) mptr; | |
381 | mqinfo->mqi_magic = MQI_MAGIC; | |
382 | mqinfo->mqi_flags = nonblock; | |
383 | ||
384 | /* Initialize header at beginning of file */ | |
385 | /* Create free list with all messages on it */ | |
386 | mqhdr->mqh_attr.mq_flags = 0; | |
387 | mqhdr->mqh_attr.mq_maxmsg = attr->mq_maxmsg; | |
388 | mqhdr->mqh_attr.mq_msgsize = attr->mq_msgsize; | |
389 | mqhdr->mqh_attr.mq_curmsgs = 0; | |
390 | mqhdr->mqh_nwait = 0; | |
391 | mqhdr->mqh_pid = 0; | |
8fbd574e | 392 | if (!AllocateLocallyUniqueId (&luid)) |
7b44665a | 393 | { |
8fbd574e CV |
394 | __seterrno (); |
395 | goto err; | |
396 | } | |
abbde487 | 397 | __small_sprintf (mqhdr->mqh_uname, "%016X%08x%08x", |
8fbd574e CV |
398 | hash_path_name (0,mqname), |
399 | luid.HighPart, luid.LowPart); | |
7b487ba9 CV |
400 | mqhdr->mqh_head = 0; |
401 | index = sizeof (struct mq_hdr); | |
402 | mqhdr->mqh_free = index; | |
403 | for (i = 0; i < attr->mq_maxmsg - 1; i++) | |
404 | { | |
405 | msghdr = (struct msg_hdr *) &mptr[index]; | |
406 | index += sizeof (struct msg_hdr) + msgsize; | |
407 | msghdr->msg_next = index; | |
408 | } | |
409 | msghdr = (struct msg_hdr *) &mptr[index]; | |
410 | msghdr->msg_next = 0; /* end of free list */ | |
411 | ||
412 | /* Initialize mutex & condition variable */ | |
93162be5 | 413 | i = ipc_mutex_init (&mqinfo->mqi_lock, mqhdr->mqh_uname); |
7b487ba9 CV |
414 | if (i != 0) |
415 | goto pthreaderr; | |
416 | ||
93162be5 | 417 | i = ipc_cond_init (&mqinfo->mqi_wait, mqhdr->mqh_uname); |
7b487ba9 CV |
418 | if (i != 0) |
419 | goto pthreaderr; | |
420 | ||
421 | /* Initialization complete, turn off user-execute bit */ | |
422 | if (fchmod (fd, mode) == -1) | |
423 | goto err; | |
424 | close (fd); | |
425 | return ((mqd_t) mqinfo); | |
426 | } | |
427 | ||
428 | exists: | |
429 | /* Open the file then memory map */ | |
430 | if ((fd = open (mqname, O_RDWR)) < 0) | |
431 | { | |
432 | if (errno == ENOENT && (oflag & O_CREAT)) | |
433 | goto again; | |
434 | goto err; | |
435 | } | |
436 | /* Make certain initialization is complete */ | |
437 | for (i = 0; i < MAX_TRIES; i++) | |
438 | { | |
439 | if (stat64 (mqname, &statbuff) == -1) | |
440 | { | |
441 | if (errno == ENOENT && (oflag & O_CREAT)) | |
442 | { | |
8fbd574e | 443 | close (fd); |
7b487ba9 CV |
444 | goto again; |
445 | } | |
446 | goto err; | |
447 | } | |
448 | if ((statbuff.st_mode & S_IXUSR) == 0) | |
449 | break; | |
450 | sleep (1); | |
451 | } | |
452 | if (i == MAX_TRIES) | |
453 | { | |
454 | set_errno (ETIMEDOUT); | |
455 | goto err; | |
456 | } | |
457 | ||
458 | filesize = statbuff.st_size; | |
459 | mptr = (int8_t *) mmap64 (NULL, (size_t) filesize, PROT_READ | PROT_WRITE, | |
460 | MAP_SHARED, fd, 0); | |
461 | if (mptr == (int8_t *) MAP_FAILED) | |
462 | goto err; | |
463 | close (fd); | |
464 | ||
465 | /* Allocate one mq_info{} for each open */ | |
466 | if (!(mqinfo = (struct mq_info *) malloc (sizeof (struct mq_info)))) | |
467 | goto err; | |
eb8a6636 | 468 | mqinfo->mqi_hdr = mqhdr = (struct mq_hdr *) mptr; |
7b487ba9 CV |
469 | mqinfo->mqi_magic = MQI_MAGIC; |
470 | mqinfo->mqi_flags = nonblock; | |
471 | ||
472 | /* Initialize mutex & condition variable */ | |
93162be5 | 473 | i = ipc_mutex_init (&mqinfo->mqi_lock, mqhdr->mqh_uname); |
7b487ba9 CV |
474 | if (i != 0) |
475 | goto pthreaderr; | |
476 | ||
93162be5 | 477 | i = ipc_cond_init (&mqinfo->mqi_wait, mqhdr->mqh_uname); |
7b487ba9 CV |
478 | if (i != 0) |
479 | goto pthreaderr; | |
480 | ||
481 | return (mqd_t) mqinfo; | |
482 | ||
483 | pthreaderr: | |
484 | errno = i; | |
485 | err: | |
486 | /* Don't let following function calls change errno */ | |
487 | save_errno save; | |
488 | ||
489 | if (created) | |
490 | unlink (mqname); | |
491 | if (mptr != (int8_t *) MAP_FAILED) | |
492 | munmap((void *) mptr, (size_t) filesize); | |
493 | if (mqinfo) | |
494 | free (mqinfo); | |
495 | close (fd); | |
496 | return (mqd_t) -1; | |
497 | } | |
498 | ||
499 | extern "C" int | |
500 | mq_getattr (mqd_t mqd, struct mq_attr *mqstat) | |
501 | { | |
502 | int n; | |
503 | struct mq_hdr *mqhdr; | |
504 | struct mq_attr *attr; | |
505 | struct mq_info *mqinfo; | |
7b44665a | 506 | |
7b487ba9 CV |
507 | myfault efault; |
508 | if (efault.faulted (EBADF)) | |
509 | return -1; | |
510 | ||
511 | mqinfo = (struct mq_info *) mqd; | |
512 | if (mqinfo->mqi_magic != MQI_MAGIC) | |
513 | { | |
514 | set_errno (EBADF); | |
515 | return -1; | |
516 | } | |
517 | mqhdr = mqinfo->mqi_hdr; | |
518 | attr = &mqhdr->mqh_attr; | |
519 | if ((n = ipc_mutex_lock (mqinfo->mqi_lock)) != 0) | |
520 | { | |
521 | errno = n; | |
522 | return -1; | |
7b44665a | 523 | } |
7b487ba9 CV |
524 | mqstat->mq_flags = mqinfo->mqi_flags; /* per-open */ |
525 | mqstat->mq_maxmsg = attr->mq_maxmsg; /* remaining three per-queue */ | |
526 | mqstat->mq_msgsize = attr->mq_msgsize; | |
527 | mqstat->mq_curmsgs = attr->mq_curmsgs; | |
528 | ||
529 | ipc_mutex_unlock (mqinfo->mqi_lock); | |
530 | return 0; | |
7b44665a | 531 | } |
7b487ba9 CV |
532 | |
533 | extern "C" int | |
534 | mq_setattr (mqd_t mqd, const struct mq_attr *mqstat, struct mq_attr *omqstat) | |
535 | { | |
536 | int n; | |
7b44665a | 537 | struct mq_hdr *mqhdr; |
7b487ba9 CV |
538 | struct mq_attr *attr; |
539 | struct mq_info *mqinfo; | |
540 | ||
541 | myfault efault; | |
542 | if (efault.faulted (EBADF)) | |
543 | return -1; | |
544 | ||
545 | mqinfo = (struct mq_info *) mqd; | |
546 | if (mqinfo->mqi_magic != MQI_MAGIC) | |
547 | { | |
548 | set_errno (EBADF); | |
549 | return -1; | |
550 | } | |
551 | mqhdr = mqinfo->mqi_hdr; | |
552 | attr = &mqhdr->mqh_attr; | |
553 | if ((n = ipc_mutex_lock (mqinfo->mqi_lock)) != 0) | |
554 | { | |
555 | errno = n; | |
556 | return -1; | |
557 | } | |
558 | ||
559 | if (omqstat != NULL) | |
560 | { | |
561 | omqstat->mq_flags = mqinfo->mqi_flags; /* previous attributes */ | |
562 | omqstat->mq_maxmsg = attr->mq_maxmsg; | |
563 | omqstat->mq_msgsize = attr->mq_msgsize; | |
564 | omqstat->mq_curmsgs = attr->mq_curmsgs; /* and current status */ | |
565 | } | |
566 | ||
567 | if (mqstat->mq_flags & O_NONBLOCK) | |
568 | mqinfo->mqi_flags |= O_NONBLOCK; | |
569 | else | |
570 | mqinfo->mqi_flags &= ~O_NONBLOCK; | |
571 | ||
572 | ipc_mutex_unlock (mqinfo->mqi_lock); | |
573 | return 0; | |
574 | } | |
575 | ||
576 | extern "C" int | |
577 | mq_notify (mqd_t mqd, const struct sigevent *notification) | |
578 | { | |
579 | int n; | |
580 | pid_t pid; | |
581 | struct mq_hdr *mqhdr; | |
582 | struct mq_info *mqinfo; | |
7b44665a | 583 | |
7b487ba9 CV |
584 | myfault efault; |
585 | if (efault.faulted (EBADF)) | |
586 | return -1; | |
587 | ||
588 | mqinfo = (struct mq_info *) mqd; | |
589 | if (mqinfo->mqi_magic != MQI_MAGIC) | |
590 | { | |
7b44665a | 591 | set_errno (EBADF); |
7b487ba9 CV |
592 | return -1; |
593 | } | |
7b44665a | 594 | mqhdr = mqinfo->mqi_hdr; |
7b487ba9 CV |
595 | if ((n = ipc_mutex_lock (mqinfo->mqi_lock)) != 0) |
596 | { | |
597 | errno = n; | |
598 | return -1; | |
599 | } | |
7b44665a | 600 | |
7b487ba9 CV |
601 | pid = getpid (); |
602 | if (!notification) | |
603 | { | |
604 | if (mqhdr->mqh_pid == pid) | |
605 | mqhdr->mqh_pid = 0; /* unregister calling process */ | |
606 | } | |
607 | else | |
608 | { | |
609 | if (mqhdr->mqh_pid != 0) | |
610 | { | |
611 | if (kill (mqhdr->mqh_pid, 0) != -1 || errno != ESRCH) | |
612 | { | |
613 | set_errno (EBUSY); | |
614 | ipc_mutex_unlock (mqinfo->mqi_lock); | |
615 | return -1; | |
616 | } | |
617 | } | |
618 | mqhdr->mqh_pid = pid; | |
619 | mqhdr->mqh_event = *notification; | |
7b44665a | 620 | } |
7b487ba9 CV |
621 | ipc_mutex_unlock (mqinfo->mqi_lock); |
622 | return 0; | |
7b44665a | 623 | } |
7b487ba9 CV |
624 | |
625 | static int | |
626 | _mq_send (mqd_t mqd, const char *ptr, size_t len, unsigned int prio, | |
627 | const struct timespec *abstime) | |
628 | { | |
629 | int n; | |
630 | long index, freeindex; | |
631 | int8_t *mptr; | |
632 | struct sigevent *sigev; | |
633 | struct mq_hdr *mqhdr; | |
634 | struct mq_attr *attr; | |
635 | struct msg_hdr *msghdr, *nmsghdr, *pmsghdr; | |
636 | struct mq_info *mqinfo; | |
637 | ||
638 | myfault efault; | |
639 | if (efault.faulted (EBADF)) | |
640 | return -1; | |
641 | ||
642 | mqinfo = (struct mq_info *) mqd; | |
643 | if (mqinfo->mqi_magic != MQI_MAGIC) | |
644 | { | |
645 | set_errno (EBADF); | |
646 | return -1; | |
647 | } | |
648 | if (prio > MQ_PRIO_MAX) | |
649 | { | |
650 | set_errno (EINVAL); | |
651 | return -1; | |
652 | } | |
653 | ||
654 | mqhdr = mqinfo->mqi_hdr; /* struct pointer */ | |
655 | mptr = (int8_t *) mqhdr; /* byte pointer */ | |
656 | attr = &mqhdr->mqh_attr; | |
657 | if ((n = ipc_mutex_lock (mqinfo->mqi_lock)) != 0) | |
658 | { | |
659 | errno = n; | |
660 | return -1; | |
661 | } | |
662 | ||
663 | if (len > (size_t) attr->mq_msgsize) | |
664 | { | |
665 | set_errno (EMSGSIZE); | |
666 | goto err; | |
667 | } | |
668 | if (attr->mq_curmsgs == 0) | |
669 | { | |
670 | if (mqhdr->mqh_pid != 0 && mqhdr->mqh_nwait == 0) | |
671 | { | |
672 | sigev = &mqhdr->mqh_event; | |
673 | if (sigev->sigev_notify == SIGEV_SIGNAL) | |
674 | sigqueue (mqhdr->mqh_pid, sigev->sigev_signo, sigev->sigev_value); | |
675 | mqhdr->mqh_pid = 0; /* unregister */ | |
676 | } | |
677 | } | |
678 | else if (attr->mq_curmsgs >= attr->mq_maxmsg) | |
679 | { | |
680 | /* Queue is full */ | |
681 | if (mqinfo->mqi_flags & O_NONBLOCK) | |
682 | { | |
683 | set_errno (EAGAIN); | |
684 | goto err; | |
685 | } | |
686 | /* Wait for room for one message on the queue */ | |
687 | while (attr->mq_curmsgs >= attr->mq_maxmsg) | |
688 | ipc_cond_timedwait (mqinfo->mqi_wait, mqinfo->mqi_lock, abstime); | |
689 | } | |
690 | ||
691 | /* nmsghdr will point to new message */ | |
692 | if ((freeindex = mqhdr->mqh_free) == 0) | |
693 | api_fatal ("mq_send: curmsgs = %ld; free = 0", attr->mq_curmsgs); | |
694 | ||
695 | nmsghdr = (struct msg_hdr *) &mptr[freeindex]; | |
696 | nmsghdr->msg_prio = prio; | |
697 | nmsghdr->msg_len = len; | |
698 | memcpy (nmsghdr + 1, ptr, len); /* copy message from caller */ | |
699 | mqhdr->mqh_free = nmsghdr->msg_next; /* new freelist head */ | |
700 | ||
701 | /* Find right place for message in linked list */ | |
702 | index = mqhdr->mqh_head; | |
703 | pmsghdr = (struct msg_hdr *) &(mqhdr->mqh_head); | |
704 | while (index) | |
705 | { | |
706 | msghdr = (struct msg_hdr *) &mptr[index]; | |
707 | if (prio > msghdr->msg_prio) | |
708 | { | |
709 | nmsghdr->msg_next = index; | |
710 | pmsghdr->msg_next = freeindex; | |
711 | break; | |
712 | } | |
713 | index = msghdr->msg_next; | |
714 | pmsghdr = msghdr; | |
715 | } | |
716 | if (index == 0) | |
717 | { | |
718 | /* Queue was empty or new goes at end of list */ | |
719 | pmsghdr->msg_next = freeindex; | |
720 | nmsghdr->msg_next = 0; | |
721 | } | |
722 | /* Wake up anyone blocked in mq_receive waiting for a message */ | |
723 | if (attr->mq_curmsgs == 0) | |
724 | ipc_cond_signal (mqinfo->mqi_wait); | |
725 | attr->mq_curmsgs++; | |
726 | ||
727 | ipc_mutex_unlock (mqinfo->mqi_lock); | |
728 | return 0; | |
729 | ||
730 | err: | |
731 | ipc_mutex_unlock (mqinfo->mqi_lock); | |
732 | return -1; | |
733 | } | |
734 | ||
735 | extern "C" int | |
736 | mq_send (mqd_t mqd, const char *ptr, size_t len, unsigned int prio) | |
737 | { | |
738 | return _mq_send (mqd, ptr, len, prio, NULL); | |
739 | } | |
740 | ||
741 | extern "C" int | |
742 | mq_timedsend (mqd_t mqd, const char *ptr, size_t len, unsigned int prio, | |
743 | const struct timespec *abstime) | |
744 | { | |
745 | return _mq_send (mqd, ptr, len, prio, abstime); | |
746 | } | |
747 | ||
748 | static ssize_t | |
749 | _mq_receive (mqd_t mqd, char *ptr, size_t maxlen, unsigned int *priop, | |
750 | const struct timespec *abstime) | |
751 | { | |
752 | int n; | |
753 | long index; | |
754 | int8_t *mptr; | |
755 | ssize_t len; | |
7b44665a | 756 | struct mq_hdr *mqhdr; |
7b487ba9 CV |
757 | struct mq_attr *attr; |
758 | struct msg_hdr *msghdr; | |
759 | struct mq_info *mqinfo; | |
760 | ||
761 | myfault efault; | |
762 | if (efault.faulted (EBADF)) | |
763 | return -1; | |
764 | ||
765 | mqinfo = (struct mq_info *) mqd; | |
766 | if (mqinfo->mqi_magic != MQI_MAGIC) | |
767 | { | |
768 | set_errno (EBADF); | |
769 | return -1; | |
770 | } | |
771 | mqhdr = mqinfo->mqi_hdr; /* struct pointer */ | |
772 | mptr = (int8_t *) mqhdr; /* byte pointer */ | |
773 | attr = &mqhdr->mqh_attr; | |
774 | if ((n = ipc_mutex_lock (mqinfo->mqi_lock)) != 0) | |
775 | { | |
776 | errno = n; | |
777 | return -1; | |
778 | } | |
779 | ||
780 | if (maxlen < (size_t) attr->mq_msgsize) | |
781 | { | |
782 | set_errno (EMSGSIZE); | |
783 | goto err; | |
784 | } | |
785 | if (attr->mq_curmsgs == 0) /* queue is empty */ | |
786 | { | |
787 | if (mqinfo->mqi_flags & O_NONBLOCK) | |
788 | { | |
789 | set_errno (EAGAIN); | |
790 | goto err; | |
791 | } | |
792 | /* Wait for a message to be placed onto queue */ | |
793 | mqhdr->mqh_nwait++; | |
794 | while (attr->mq_curmsgs == 0) | |
795 | ipc_cond_timedwait (mqinfo->mqi_wait, mqinfo->mqi_lock, abstime); | |
796 | mqhdr->mqh_nwait--; | |
797 | } | |
798 | ||
799 | if ((index = mqhdr->mqh_head) == 0) | |
800 | api_fatal ("mq_receive: curmsgs = %ld; head = 0", attr->mq_curmsgs); | |
801 | ||
802 | msghdr = (struct msg_hdr *) &mptr[index]; | |
803 | mqhdr->mqh_head = msghdr->msg_next; /* new head of list */ | |
804 | len = msghdr->msg_len; | |
805 | memcpy(ptr, msghdr + 1, len); /* copy the message itself */ | |
806 | if (priop != NULL) | |
807 | *priop = msghdr->msg_prio; | |
808 | ||
809 | /* Just-read message goes to front of free list */ | |
810 | msghdr->msg_next = mqhdr->mqh_free; | |
811 | mqhdr->mqh_free = index; | |
812 | ||
813 | /* Wake up anyone blocked in mq_send waiting for room */ | |
814 | if (attr->mq_curmsgs == attr->mq_maxmsg) | |
815 | ipc_cond_signal (mqinfo->mqi_wait); | |
816 | attr->mq_curmsgs--; | |
817 | ||
818 | ipc_mutex_unlock (mqinfo->mqi_lock); | |
819 | return len; | |
820 | ||
821 | err: | |
822 | ipc_mutex_unlock (mqinfo->mqi_lock); | |
823 | return -1; | |
824 | } | |
825 | ||
826 | extern "C" ssize_t | |
827 | mq_receive (mqd_t mqd, char *ptr, size_t maxlen, unsigned int *priop) | |
828 | { | |
829 | return _mq_receive (mqd, ptr, maxlen, priop, NULL); | |
830 | } | |
831 | ||
832 | extern "C" ssize_t | |
833 | mq_timedreceive (mqd_t mqd, char *ptr, size_t maxlen, unsigned int *priop, | |
834 | const struct timespec *abstime) | |
835 | { | |
836 | return _mq_receive (mqd, ptr, maxlen, priop, abstime); | |
837 | } | |
838 | ||
839 | extern "C" int | |
840 | mq_close (mqd_t mqd) | |
841 | { | |
842 | long msgsize, filesize; | |
843 | struct mq_hdr *mqhdr; | |
844 | struct mq_attr *attr; | |
845 | struct mq_info *mqinfo; | |
846 | ||
847 | myfault efault; | |
848 | if (efault.faulted (EBADF)) | |
849 | return -1; | |
850 | ||
851 | mqinfo = (struct mq_info *) mqd; | |
852 | if (mqinfo->mqi_magic != MQI_MAGIC) | |
853 | { | |
854 | set_errno (EBADF); | |
855 | return -1; | |
856 | } | |
857 | mqhdr = mqinfo->mqi_hdr; | |
858 | attr = &mqhdr->mqh_attr; | |
859 | ||
860 | if (mq_notify (mqd, NULL)) /* unregister calling process */ | |
861 | return -1; | |
862 | ||
863 | msgsize = MSGSIZE (attr->mq_msgsize); | |
864 | filesize = sizeof (struct mq_hdr) | |
865 | + (attr->mq_maxmsg * (sizeof (struct msg_hdr) + msgsize)); | |
866 | if (munmap (mqinfo->mqi_hdr, filesize) == -1) | |
867 | return -1; | |
868 | ||
869 | mqinfo->mqi_magic = 0; /* just in case */ | |
870 | ipc_cond_close (mqinfo->mqi_wait); | |
871 | ipc_mutex_close (mqinfo->mqi_lock); | |
872 | free (mqinfo); | |
873 | return 0; | |
874 | } | |
875 | ||
876 | extern "C" int | |
877 | mq_unlink (const char *name) | |
878 | { | |
547ad329 CV |
879 | size_t len = strlen (name); |
880 | char mqname[ipc_names[mqueue].prefix_len + len]; | |
7b487ba9 | 881 | |
547ad329 | 882 | if (!check_path (mqname, mqueue, name, len)) |
7b487ba9 CV |
883 | return -1; |
884 | if (unlink (mqname) == -1) | |
885 | return -1; | |
886 | return 0; | |
887 | } | |
888 | ||
8fbd574e CV |
889 | /* POSIX named semaphore implementation. Loosely based on Richard W. STEPHENS |
890 | implementation as far as sem_open is concerned, but under the hood using | |
891 | the already existing semaphore class in thread.cc. Using a file backed | |
892 | solution allows to implement kernel persistent named semaphores. */ | |
893 | ||
894 | struct sem_finfo | |
895 | { | |
896 | unsigned int value; | |
897 | unsigned long long hash; | |
898 | LUID luid; | |
899 | }; | |
900 | ||
901 | extern "C" sem_t * | |
902 | sem_open (const char *name, int oflag, ...) | |
903 | { | |
904 | int i, fd, created; | |
905 | va_list ap; | |
906 | mode_t mode = 0; | |
907 | unsigned int value = 0; | |
908 | struct __stat64 statbuff; | |
909 | sem_t *sem = SEM_FAILED; | |
910 | sem_finfo sf; | |
8fbd574e CV |
911 | bool wasopen = false; |
912 | ipc_flock file; | |
913 | ||
547ad329 CV |
914 | size_t len = strlen (name); |
915 | char semname[ipc_names[semaphore].prefix_len + len]; | |
916 | ||
917 | if (!check_path (semname, semaphore, name, len)) | |
8fbd574e CV |
918 | return SEM_FAILED; |
919 | ||
920 | myfault efault; | |
921 | if (efault.faulted (EFAULT)) | |
922 | return SEM_FAILED; | |
923 | ||
924 | created = 0; | |
925 | oflag &= (O_CREAT | O_EXCL); | |
926 | ||
927 | again: | |
928 | if (oflag & O_CREAT) | |
929 | { | |
930 | va_start (ap, oflag); /* init ap to final named argument */ | |
931 | mode = va_arg (ap, mode_t) & ~S_IXUSR; | |
932 | value = va_arg (ap, unsigned int); | |
933 | va_end (ap); | |
934 | ||
935 | /* Open and specify O_EXCL and user-execute */ | |
936 | fd = open (semname, oflag | O_EXCL | O_RDWR, mode | S_IXUSR); | |
937 | if (fd < 0) | |
7b44665a | 938 | { |
8fbd574e CV |
939 | if (errno == EEXIST && (oflag & O_EXCL) == 0) |
940 | goto exists; /* already exists, OK */ | |
941 | return SEM_FAILED; | |
942 | } | |
943 | created = 1; | |
944 | /* First one to create the file initializes it. */ | |
945 | if (!AllocateLocallyUniqueId (&sf.luid)) | |
7b44665a | 946 | { |
8fbd574e CV |
947 | __seterrno (); |
948 | goto err; | |
949 | } | |
950 | sf.value = value; | |
951 | sf.hash = hash_path_name (0, semname); | |
952 | if (write (fd, &sf, sizeof sf) != sizeof sf) | |
7b44665a | 953 | goto err; |
8fbd574e CV |
954 | sem = semaphore::open (sf.hash, sf.luid, fd, oflag, mode, value, wasopen); |
955 | if (sem == SEM_FAILED) | |
7b44665a | 956 | goto err; |
8fbd574e CV |
957 | /* Initialization complete, turn off user-execute bit */ |
958 | if (fchmod (fd, mode) == -1) | |
959 | goto err; | |
960 | /* Don't close (fd); */ | |
961 | return sem; | |
962 | } | |
963 | ||
964 | exists: | |
965 | /* Open the file and fetch the semaphore name. */ | |
966 | if ((fd = open (semname, O_RDWR)) < 0) | |
967 | { | |
968 | if (errno == ENOENT && (oflag & O_CREAT)) | |
969 | goto again; | |
970 | goto err; | |
971 | } | |
972 | /* Make certain initialization is complete */ | |
973 | for (i = 0; i < MAX_TRIES; i++) | |
974 | { | |
975 | if (stat64 (semname, &statbuff) == -1) | |
976 | { | |
977 | if (errno == ENOENT && (oflag & O_CREAT)) | |
978 | { | |
979 | close (fd); | |
980 | goto again; | |
981 | } | |
982 | goto err; | |
983 | } | |
984 | if ((statbuff.st_mode & S_IXUSR) == 0) | |
985 | break; | |
986 | sleep (1); | |
987 | } | |
988 | if (i == MAX_TRIES) | |
989 | { | |
990 | set_errno (ETIMEDOUT); | |
991 | goto err; | |
992 | } | |
993 | if (file.lock (fd, sizeof sf)) | |
994 | goto err; | |
995 | if (read (fd, &sf, sizeof sf) != sizeof sf) | |
996 | goto err; | |
997 | sem = semaphore::open (sf.hash, sf.luid, fd, oflag, mode, sf.value, wasopen); | |
998 | file.unlock (fd); | |
999 | if (sem == SEM_FAILED) | |
1000 | goto err; | |
1001 | /* If wasopen is set, the semaphore was already opened and we already have | |
1002 | an open file descriptor pointing to the file. This means, we have to | |
1003 | close the file descriptor created in this call. It won't be stored | |
1004 | anywhere anyway. */ | |
1005 | if (wasopen) | |
1006 | close (fd); | |
1007 | return sem; | |
1008 | ||
1009 | err: | |
1010 | /* Don't let following function calls change errno */ | |
1011 | save_errno save; | |
1012 | ||
1013 | file.unlock (fd); | |
1014 | if (created) | |
1015 | unlink (semname); | |
1016 | if (sem != SEM_FAILED) | |
1017 | semaphore::close (sem); | |
1018 | close (fd); | |
1019 | return SEM_FAILED; | |
1020 | } | |
1021 | ||
1022 | int | |
1023 | _sem_close (sem_t *sem, bool do_close) | |
1024 | { | |
1025 | sem_finfo sf; | |
1026 | int fd, ret = -1; | |
1027 | ipc_flock file; | |
1028 | ||
1029 | if (semaphore::getinternal (sem, &fd, &sf.hash, &sf.luid, &sf.value) == -1) | |
1030 | return -1; | |
1031 | if (!file.lock (fd, sizeof sf) | |
1032 | && lseek64 (fd, 0LL, SEEK_SET) != (_off64_t) -1 | |
1033 | && write (fd, &sf, sizeof sf) == sizeof sf) | |
1034 | ret = do_close ? semaphore::close (sem) : 0; | |
1035 | ||
1036 | /* Don't let following function calls change errno */ | |
1037 | save_errno save; | |
1038 | file.unlock (fd); | |
1039 | close (fd); | |
1040 | ||
1041 | return ret; | |
1042 | } | |
1043 | ||
1044 | extern "C" int | |
1045 | sem_close (sem_t *sem) | |
1046 | { | |
1047 | return _sem_close (sem, true); | |
1048 | } | |
1049 | ||
1050 | extern "C" int | |
1051 | sem_unlink (const char *name) | |
1052 | { | |
547ad329 CV |
1053 | size_t len = strlen (name); |
1054 | char semname[ipc_names[semaphore].prefix_len + len]; | |
8fbd574e | 1055 | |
547ad329 | 1056 | if (!check_path (semname, semaphore, name, len)) |
8fbd574e CV |
1057 | return -1; |
1058 | if (unlink (semname) == -1) | |
1059 | return -1; | |
1060 | return 0; | |
1061 | } |