1 /* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements. See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License. You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "apr_arch_shm.h"
18
19 #include "apr_general.h"
20 #include "apr_errno.h"
21 #include "apr_user.h"
22 #include "apr_strings.h"
23
shm_cleanup_owner(void * m_)24 static apr_status_t shm_cleanup_owner(void *m_)
25 {
26 apr_shm_t *m = (apr_shm_t *)m_;
27
28 /* anonymous shared memory */
29 if (m->filename == NULL) {
30 #if APR_USE_SHMEM_MMAP_ZERO || APR_USE_SHMEM_MMAP_ANON
31 if (munmap(m->base, m->realsize) == -1) {
32 return errno;
33 }
34 return APR_SUCCESS;
35 #endif
36 #if APR_USE_SHMEM_SHMGET_ANON
37 if (shmdt(m->base) == -1) {
38 return errno;
39 }
40 /* This segment will automatically remove itself after all
41 * references have detached. */
42 return APR_SUCCESS;
43 #endif
44 }
45
46 /* name-based shared memory */
47 else {
48 #if APR_USE_SHMEM_MMAP_TMP
49 if (munmap(m->base, m->realsize) == -1) {
50 return errno;
51 }
52 return apr_file_remove(m->filename, m->pool);
53 #endif
54 #if APR_USE_SHMEM_MMAP_SHM
55 if (munmap(m->base, m->realsize) == -1) {
56 return errno;
57 }
58 if (shm_unlink(m->filename) == -1) {
59 return errno;
60 }
61 return APR_SUCCESS;
62 #endif
63 #if APR_USE_SHMEM_SHMGET
64 /* Indicate that the segment is to be destroyed as soon
65 * as all processes have detached. This also disallows any
66 * new attachments to the segment. */
67 if (shmctl(m->shmid, IPC_RMID, NULL) == -1) {
68 return errno;
69 }
70 if (shmdt(m->base) == -1) {
71 return errno;
72 }
73 return apr_file_remove(m->filename, m->pool);
74 #endif
75 }
76
77 return APR_ENOTIMPL;
78 }
79
apr_shm_create(apr_shm_t ** m,apr_size_t reqsize,const char * filename,apr_pool_t * pool)80 APR_DECLARE(apr_status_t) apr_shm_create(apr_shm_t **m,
81 apr_size_t reqsize,
82 const char *filename,
83 apr_pool_t *pool)
84 {
85 apr_shm_t *new_m;
86 apr_status_t status;
87 #if APR_USE_SHMEM_SHMGET || APR_USE_SHMEM_SHMGET_ANON
88 struct shmid_ds shmbuf;
89 apr_uid_t uid;
90 apr_gid_t gid;
91 #endif
92 #if APR_USE_SHMEM_MMAP_TMP || APR_USE_SHMEM_MMAP_SHM || \
93 APR_USE_SHMEM_MMAP_ZERO
94 int tmpfd;
95 #endif
96 #if APR_USE_SHMEM_SHMGET
97 apr_size_t nbytes;
98 key_t shmkey;
99 #endif
100 #if APR_USE_SHMEM_MMAP_ZERO || APR_USE_SHMEM_SHMGET || \
101 APR_USE_SHMEM_MMAP_TMP || APR_USE_SHMEM_MMAP_SHM
102 apr_file_t *file; /* file where metadata is stored */
103 #endif
104
105 /* Check if they want anonymous or name-based shared memory */
106 if (filename == NULL) {
107 #if APR_USE_SHMEM_MMAP_ZERO || APR_USE_SHMEM_MMAP_ANON
108 new_m = apr_palloc(pool, sizeof(apr_shm_t));
109 new_m->pool = pool;
110 new_m->reqsize = reqsize;
111 new_m->realsize = reqsize +
112 APR_ALIGN_DEFAULT(sizeof(apr_size_t)); /* room for metadata */
113 new_m->filename = NULL;
114
115 #if APR_USE_SHMEM_MMAP_ZERO
116 status = apr_file_open(&file, "/dev/zero", APR_READ | APR_WRITE,
117 APR_OS_DEFAULT, pool);
118 if (status != APR_SUCCESS) {
119 return status;
120 }
121 status = apr_os_file_get(&tmpfd, file);
122 if (status != APR_SUCCESS) {
123 return status;
124 }
125
126 new_m->base = mmap(NULL, new_m->realsize, PROT_READ|PROT_WRITE,
127 MAP_SHARED, tmpfd, 0);
128 if (new_m->base == (void *)MAP_FAILED) {
129 return errno;
130 }
131
132 status = apr_file_close(file);
133 if (status != APR_SUCCESS) {
134 return status;
135 }
136
137 /* store the real size in the metadata */
138 *(apr_size_t*)(new_m->base) = new_m->realsize;
139 /* metadata isn't usable */
140 new_m->usable = (char *)new_m->base + APR_ALIGN_DEFAULT(sizeof(apr_size_t));
141
142 apr_pool_cleanup_register(new_m->pool, new_m, shm_cleanup_owner,
143 apr_pool_cleanup_null);
144 *m = new_m;
145 return APR_SUCCESS;
146
147 #elif APR_USE_SHMEM_MMAP_ANON
148 new_m->base = mmap(NULL, new_m->realsize, PROT_READ|PROT_WRITE,
149 MAP_ANON|MAP_SHARED, -1, 0);
150 if (new_m->base == (void *)MAP_FAILED) {
151 return errno;
152 }
153
154 /* store the real size in the metadata */
155 *(apr_size_t*)(new_m->base) = new_m->realsize;
156 /* metadata isn't usable */
157 new_m->usable = (char *)new_m->base + APR_ALIGN_DEFAULT(sizeof(apr_size_t));
158
159 apr_pool_cleanup_register(new_m->pool, new_m, shm_cleanup_owner,
160 apr_pool_cleanup_null);
161 *m = new_m;
162 return APR_SUCCESS;
163
164 #endif /* APR_USE_SHMEM_MMAP_ZERO */
165 #endif /* APR_USE_SHMEM_MMAP_ZERO || APR_USE_SHMEM_MMAP_ANON */
166 #if APR_USE_SHMEM_SHMGET_ANON
167
168 new_m = apr_palloc(pool, sizeof(apr_shm_t));
169 new_m->pool = pool;
170 new_m->reqsize = reqsize;
171 new_m->realsize = reqsize;
172 new_m->filename = NULL;
173
174 if ((new_m->shmid = shmget(IPC_PRIVATE, new_m->realsize,
175 SHM_R | SHM_W | IPC_CREAT)) < 0) {
176 return errno;
177 }
178
179 if ((new_m->base = shmat(new_m->shmid, NULL, 0)) == (void *)-1) {
180 return errno;
181 }
182 new_m->usable = new_m->base;
183
184 if (shmctl(new_m->shmid, IPC_STAT, &shmbuf) == -1) {
185 return errno;
186 }
187 apr_uid_current(&uid, &gid, pool);
188 shmbuf.shm_perm.uid = uid;
189 shmbuf.shm_perm.gid = gid;
190 if (shmctl(new_m->shmid, IPC_SET, &shmbuf) == -1) {
191 return errno;
192 }
193
194 /* Remove the segment once use count hits zero.
195 * We will not attach to this segment again, since it is
196 * anonymous memory, so it is ok to mark it for deletion.
197 */
198 if (shmctl(new_m->shmid, IPC_RMID, NULL) == -1) {
199 return errno;
200 }
201
202 apr_pool_cleanup_register(new_m->pool, new_m, shm_cleanup_owner,
203 apr_pool_cleanup_null);
204 *m = new_m;
205 return APR_SUCCESS;
206 #endif /* APR_USE_SHMEM_SHMGET_ANON */
207 /* It is an error if they want anonymous memory but we don't have it. */
208 return APR_ENOTIMPL; /* requested anonymous but we don't have it */
209 }
210
211 /* Name-based shared memory */
212 else {
213 new_m = apr_palloc(pool, sizeof(apr_shm_t));
214 new_m->pool = pool;
215 new_m->reqsize = reqsize;
216 new_m->filename = apr_pstrdup(pool, filename);
217
218 #if APR_USE_SHMEM_MMAP_TMP || APR_USE_SHMEM_MMAP_SHM
219 new_m->realsize = reqsize +
220 APR_ALIGN_DEFAULT(sizeof(apr_size_t)); /* room for metadata */
221 /* FIXME: Ignore error for now. *
222 * status = apr_file_remove(file, pool);*/
223 status = APR_SUCCESS;
224
225 #if APR_USE_SHMEM_MMAP_TMP
226 /* FIXME: Is APR_OS_DEFAULT sufficient? */
227 status = apr_file_open(&file, filename,
228 APR_READ | APR_WRITE | APR_CREATE | APR_EXCL,
229 APR_OS_DEFAULT, pool);
230 if (status != APR_SUCCESS) {
231 return status;
232 }
233
234 status = apr_os_file_get(&tmpfd, file);
235 if (status != APR_SUCCESS) {
236 apr_file_close(file); /* ignore errors, we're failing */
237 apr_file_remove(new_m->filename, new_m->pool);
238 return status;
239 }
240
241 status = apr_file_trunc(file, new_m->realsize);
242 if (status != APR_SUCCESS) {
243 apr_file_close(file); /* ignore errors, we're failing */
244 apr_file_remove(new_m->filename, new_m->pool);
245 return status;
246 }
247
248 new_m->base = mmap(NULL, new_m->realsize, PROT_READ | PROT_WRITE,
249 MAP_SHARED, tmpfd, 0);
250 /* FIXME: check for errors */
251
252 status = apr_file_close(file);
253 if (status != APR_SUCCESS) {
254 return status;
255 }
256 #endif /* APR_USE_SHMEM_MMAP_TMP */
257 #if APR_USE_SHMEM_MMAP_SHM
258 tmpfd = shm_open(filename, O_RDWR | O_CREAT | O_EXCL, 0644);
259 if (tmpfd == -1) {
260 return errno;
261 }
262
263 status = apr_os_file_put(&file, &tmpfd,
264 APR_READ | APR_WRITE | APR_CREATE | APR_EXCL,
265 pool);
266 if (status != APR_SUCCESS) {
267 return status;
268 }
269
270 status = apr_file_trunc(file, new_m->realsize);
271 if (status != APR_SUCCESS) {
272 shm_unlink(filename); /* we're failing, remove the object */
273 return status;
274 }
275 new_m->base = mmap(NULL, reqsize, PROT_READ | PROT_WRITE,
276 MAP_SHARED, tmpfd, 0);
277
278 /* FIXME: check for errors */
279
280 status = apr_file_close(file);
281 if (status != APR_SUCCESS) {
282 return status;
283 }
284 #endif /* APR_USE_SHMEM_MMAP_SHM */
285
286 /* store the real size in the metadata */
287 *(apr_size_t*)(new_m->base) = new_m->realsize;
288 /* metadata isn't usable */
289 new_m->usable = (char *)new_m->base + APR_ALIGN_DEFAULT(sizeof(apr_size_t));
290
291 apr_pool_cleanup_register(new_m->pool, new_m, shm_cleanup_owner,
292 apr_pool_cleanup_null);
293 *m = new_m;
294 return APR_SUCCESS;
295
296 #endif /* APR_USE_SHMEM_MMAP_TMP || APR_USE_SHMEM_MMAP_SHM */
297
298 #if APR_USE_SHMEM_SHMGET
299 new_m->realsize = reqsize;
300
301 /* FIXME: APR_OS_DEFAULT is too permissive, switch to 600 I think. */
302 status = apr_file_open(&file, filename,
303 APR_WRITE | APR_CREATE | APR_EXCL,
304 APR_OS_DEFAULT, pool);
305 if (status != APR_SUCCESS) {
306 return status;
307 }
308
309 /* ftok() (on solaris at least) requires that the file actually
310 * exist before calling ftok(). */
311 shmkey = ftok(filename, 1);
312 if (shmkey == (key_t)-1) {
313 return errno;
314 }
315
316 if ((new_m->shmid = shmget(shmkey, new_m->realsize,
317 SHM_R | SHM_W | IPC_CREAT | IPC_EXCL)) < 0) {
318 return errno;
319 }
320
321 if ((new_m->base = shmat(new_m->shmid, NULL, 0)) == (void *)-1) {
322 return errno;
323 }
324 new_m->usable = new_m->base;
325
326 if (shmctl(new_m->shmid, IPC_STAT, &shmbuf) == -1) {
327 return errno;
328 }
329 apr_uid_current(&uid, &gid, pool);
330 shmbuf.shm_perm.uid = uid;
331 shmbuf.shm_perm.gid = gid;
332 if (shmctl(new_m->shmid, IPC_SET, &shmbuf) == -1) {
333 return errno;
334 }
335
336 nbytes = sizeof(reqsize);
337 status = apr_file_write(file, (const void *)&reqsize,
338 &nbytes);
339 if (status != APR_SUCCESS) {
340 return status;
341 }
342 status = apr_file_close(file);
343 if (status != APR_SUCCESS) {
344 return status;
345 }
346
347 apr_pool_cleanup_register(new_m->pool, new_m, shm_cleanup_owner,
348 apr_pool_cleanup_null);
349 *m = new_m;
350 return APR_SUCCESS;
351
352 #endif /* APR_USE_SHMEM_SHMGET */
353 }
354
355 return APR_ENOTIMPL;
356 }
357
apr_shm_remove(const char * filename,apr_pool_t * pool)358 APR_DECLARE(apr_status_t) apr_shm_remove(const char *filename,
359 apr_pool_t *pool)
360 {
361 #if APR_USE_SHMEM_SHMGET
362 apr_status_t status;
363 apr_file_t *file;
364 key_t shmkey;
365 int shmid;
366 #endif
367
368 #if APR_USE_SHMEM_MMAP_TMP
369 return apr_file_remove(filename, pool);
370 #endif
371 #if APR_USE_SHMEM_MMAP_SHM
372 if (shm_unlink(filename) == -1) {
373 return errno;
374 }
375 return APR_SUCCESS;
376 #endif
377 #if APR_USE_SHMEM_SHMGET
378 /* Presume that the file already exists; just open for writing */
379 status = apr_file_open(&file, filename, APR_WRITE,
380 APR_OS_DEFAULT, pool);
381 if (status) {
382 return status;
383 }
384
385 /* ftok() (on solaris at least) requires that the file actually
386 * exist before calling ftok(). */
387 shmkey = ftok(filename, 1);
388 if (shmkey == (key_t)-1) {
389 goto shm_remove_failed;
390 }
391
392 apr_file_close(file);
393
394 if ((shmid = shmget(shmkey, 0, SHM_R | SHM_W)) < 0) {
395 goto shm_remove_failed;
396 }
397
398 /* Indicate that the segment is to be destroyed as soon
399 * as all processes have detached. This also disallows any
400 * new attachments to the segment. */
401 if (shmctl(shmid, IPC_RMID, NULL) == -1) {
402 goto shm_remove_failed;
403 }
404 return apr_file_remove(filename, pool);
405
406 shm_remove_failed:
407 status = errno;
408 /* ensure the file has been removed anyway. */
409 apr_file_remove(filename, pool);
410 return status;
411 #endif
412
413 /* No support for anonymous shm */
414 return APR_ENOTIMPL;
415 }
416
apr_shm_destroy(apr_shm_t * m)417 APR_DECLARE(apr_status_t) apr_shm_destroy(apr_shm_t *m)
418 {
419 return apr_pool_cleanup_run(m->pool, m, shm_cleanup_owner);
420 }
421
shm_cleanup_attach(void * m_)422 static apr_status_t shm_cleanup_attach(void *m_)
423 {
424 apr_shm_t *m = (apr_shm_t *)m_;
425
426 if (m->filename == NULL) {
427 /* It doesn't make sense to detach from an anonymous memory segment. */
428 return APR_EINVAL;
429 }
430 else {
431 #if APR_USE_SHMEM_MMAP_TMP || APR_USE_SHMEM_MMAP_SHM
432 if (munmap(m->base, m->realsize) == -1) {
433 return errno;
434 }
435 return APR_SUCCESS;
436 #endif /* APR_USE_SHMEM_MMAP_TMP || APR_USE_SHMEM_MMAP_SHM */
437 #if APR_USE_SHMEM_SHMGET
438 if (shmdt(m->base) == -1) {
439 return errno;
440 }
441 return APR_SUCCESS;
442 #endif
443 }
444
445 return APR_ENOTIMPL;
446 }
447
apr_shm_attach(apr_shm_t ** m,const char * filename,apr_pool_t * pool)448 APR_DECLARE(apr_status_t) apr_shm_attach(apr_shm_t **m,
449 const char *filename,
450 apr_pool_t *pool)
451 {
452 if (filename == NULL) {
453 /* It doesn't make sense to attach to a segment if you don't know
454 * the filename. */
455 return APR_EINVAL;
456 }
457 else {
458 #if APR_USE_SHMEM_MMAP_TMP || APR_USE_SHMEM_MMAP_SHM
459 apr_shm_t *new_m;
460 apr_status_t status;
461 int tmpfd;
462 apr_file_t *file; /* file where metadata is stored */
463 apr_size_t nbytes;
464
465 new_m = apr_palloc(pool, sizeof(apr_shm_t));
466 new_m->pool = pool;
467 new_m->filename = apr_pstrdup(pool, filename);
468
469 status = apr_file_open(&file, filename,
470 APR_READ | APR_WRITE,
471 APR_OS_DEFAULT, pool);
472 if (status != APR_SUCCESS) {
473 return status;
474 }
475 status = apr_os_file_get(&tmpfd, file);
476 if (status != APR_SUCCESS) {
477 return status;
478 }
479
480 nbytes = sizeof(new_m->realsize);
481 status = apr_file_read(file, (void *)&(new_m->realsize),
482 &nbytes);
483 if (status != APR_SUCCESS) {
484 return status;
485 }
486
487 status = apr_os_file_get(&tmpfd, file);
488 if (status != APR_SUCCESS) {
489 apr_file_close(file); /* ignore errors, we're failing */
490 apr_file_remove(new_m->filename, new_m->pool);
491 return status;
492 }
493
494 new_m->reqsize = new_m->realsize - sizeof(apr_size_t);
495
496 new_m->base = mmap(NULL, new_m->realsize, PROT_READ | PROT_WRITE,
497 MAP_SHARED, tmpfd, 0);
498 /* FIXME: check for errors */
499
500 status = apr_file_close(file);
501 if (status != APR_SUCCESS) {
502 return status;
503 }
504
505 /* metadata isn't part of the usable segment */
506 new_m->usable = (char *)new_m->base + APR_ALIGN_DEFAULT(sizeof(apr_size_t));
507
508 apr_pool_cleanup_register(new_m->pool, new_m, shm_cleanup_attach,
509 apr_pool_cleanup_null);
510 *m = new_m;
511 return APR_SUCCESS;
512
513 #endif /* APR_USE_SHMEM_MMAP_TMP || APR_USE_SHMEM_MMAP_SHM */
514 #if APR_USE_SHMEM_SHMGET
515 apr_shm_t *new_m;
516 apr_status_t status;
517 apr_file_t *file; /* file where metadata is stored */
518 apr_size_t nbytes;
519 key_t shmkey;
520
521 new_m = apr_palloc(pool, sizeof(apr_shm_t));
522
523 status = apr_file_open(&file, filename,
524 APR_READ, APR_OS_DEFAULT, pool);
525 if (status != APR_SUCCESS) {
526 return status;
527 }
528
529 nbytes = sizeof(new_m->reqsize);
530 status = apr_file_read(file, (void *)&(new_m->reqsize),
531 &nbytes);
532 if (status != APR_SUCCESS) {
533 return status;
534 }
535 status = apr_file_close(file);
536 if (status != APR_SUCCESS) {
537 return status;
538 }
539
540 new_m->filename = apr_pstrdup(pool, filename);
541 new_m->pool = pool;
542 shmkey = ftok(filename, 1);
543 if (shmkey == (key_t)-1) {
544 return errno;
545 }
546 if ((new_m->shmid = shmget(shmkey, 0, SHM_R | SHM_W)) == -1) {
547 return errno;
548 }
549 if ((new_m->base = shmat(new_m->shmid, NULL, 0)) == (void *)-1) {
550 return errno;
551 }
552 new_m->usable = new_m->base;
553 new_m->realsize = new_m->reqsize;
554
555 apr_pool_cleanup_register(new_m->pool, new_m, shm_cleanup_attach,
556 apr_pool_cleanup_null);
557 *m = new_m;
558 return APR_SUCCESS;
559
560 #endif /* APR_USE_SHMEM_SHMGET */
561 }
562
563 return APR_ENOTIMPL;
564 }
565
apr_shm_detach(apr_shm_t * m)566 APR_DECLARE(apr_status_t) apr_shm_detach(apr_shm_t *m)
567 {
568 apr_status_t rv = shm_cleanup_attach(m);
569 apr_pool_cleanup_kill(m->pool, m, shm_cleanup_attach);
570 return rv;
571 }
572
apr_shm_baseaddr_get(const apr_shm_t * m)573 APR_DECLARE(void *) apr_shm_baseaddr_get(const apr_shm_t *m)
574 {
575 return m->usable;
576 }
577
apr_shm_size_get(const apr_shm_t * m)578 APR_DECLARE(apr_size_t) apr_shm_size_get(const apr_shm_t *m)
579 {
580 return m->reqsize;
581 }
582
583 APR_POOL_IMPLEMENT_ACCESSOR(shm)
584
APR_DECLARE(apr_status_t)585 APR_DECLARE(apr_status_t) apr_os_shm_get(apr_os_shm_t *osshm,
586 apr_shm_t *shm)
587 {
588 return APR_ENOTIMPL;
589 }
590
apr_os_shm_put(apr_shm_t ** m,apr_os_shm_t * osshm,apr_pool_t * pool)591 APR_DECLARE(apr_status_t) apr_os_shm_put(apr_shm_t **m,
592 apr_os_shm_t *osshm,
593 apr_pool_t *pool)
594 {
595 return APR_ENOTIMPL;
596 }
597
598