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1ce86c9a JD |
1 | /* |
2 | * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca> | |
3 | * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or | |
6 | * modify it under the terms of the GNU General Public License | |
7 | * as published by the Free Software Foundation; either version 2 | |
8 | * of the License, or (at your option) any later version. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
18 | */ | |
19 | ||
20 | #define _GNU_SOURCE | |
21 | #include <fcntl.h> | |
22 | #include <poll.h> | |
23 | #include <pthread.h> | |
24 | #include <stdlib.h> | |
25 | #include <string.h> | |
26 | #include <sys/mman.h> | |
27 | #include <sys/socket.h> | |
28 | #include <sys/types.h> | |
29 | #include <unistd.h> | |
30 | #include <urcu/list.h> | |
31 | ||
32 | #include "libkernelctl.h" | |
33 | #include "liblttkconsumerd.h" | |
34 | #include "lttngerr.h" | |
35 | ||
36 | /* Init the list of FDs */ | |
37 | static struct kconsumerd_fd_list kconsumerd_fd_list = { | |
38 | .head = CDS_LIST_HEAD_INIT(kconsumerd_fd_list.head), | |
39 | }; | |
40 | ||
41 | /* Number of element for the list below. */ | |
42 | static unsigned int kconsumerd_fds_count; | |
43 | ||
44 | /* If the local array of FDs needs update in the poll function */ | |
45 | static unsigned int kconsumerd_update_fd_array = 1; | |
46 | ||
47 | /* lock the fd array and structures */ | |
48 | static pthread_mutex_t kconsumerd_lock_fds; | |
49 | ||
50 | /* communication with splice */ | |
51 | static int kconsumerd_thread_pipe[2]; | |
52 | ||
53 | /* pipe to wake the poll thread when necessary */ | |
54 | static int kconsumerd_poll_pipe[2]; | |
55 | ||
56 | /* timeout parameter, to control the polling thread grace period */ | |
57 | static int kconsumerd_poll_timeout = -1; | |
58 | ||
59 | /* socket to communicate errors with sessiond */ | |
60 | static int kconsumerd_error_socket; | |
61 | ||
62 | /* socket to exchange commands with sessiond */ | |
63 | static char *kconsumerd_command_sock_path; | |
64 | ||
65 | /* flag to inform the polling thread to kconsumerd_quit when all fd hung up */ | |
66 | static int kconsumerd_quit = 0; | |
67 | ||
68 | /* | |
69 | * kconsumerd_set_error_socket | |
70 | * | |
71 | * Set the error socket | |
72 | */ | |
73 | void kconsumerd_set_error_socket(int sock) | |
74 | { | |
75 | kconsumerd_error_socket = sock; | |
76 | } | |
77 | ||
78 | /* | |
79 | * kconsumerd_set_command_socket_path | |
80 | * | |
81 | * Set the command socket path | |
82 | */ | |
83 | void kconsumerd_set_command_socket_path(char *sock) | |
84 | { | |
85 | kconsumerd_command_sock_path = sock; | |
86 | } | |
87 | ||
38079a1b DG |
88 | /* |
89 | * kconsumerd_find_session_fd | |
90 | * | |
91 | * Find a session fd in the global list. | |
92 | * | |
93 | * Return 1 if found else 0 | |
94 | */ | |
95 | static int kconsumerd_find_session_fd(int fd) | |
96 | { | |
97 | struct kconsumerd_fd *iter; | |
98 | ||
99 | pthread_mutex_lock(&kconsumerd_lock_fds); | |
100 | cds_list_for_each_entry(iter, &kconsumerd_fd_list.head, list) { | |
101 | if (iter->sessiond_fd == fd) { | |
102 | DBG("Duplicate session fd %d", fd); | |
103 | pthread_mutex_unlock(&kconsumerd_lock_fds); | |
104 | return 1; | |
105 | } | |
106 | } | |
107 | pthread_mutex_unlock(&kconsumerd_lock_fds); | |
108 | ||
109 | return 0; | |
110 | } | |
111 | ||
1ce86c9a JD |
112 | /* |
113 | * kconsumerd_del_fd | |
114 | * | |
115 | * Remove a fd from the global list protected by a mutex | |
116 | */ | |
117 | static void kconsumerd_del_fd(struct kconsumerd_fd *lcf) | |
118 | { | |
119 | pthread_mutex_lock(&kconsumerd_lock_fds); | |
120 | cds_list_del(&lcf->list); | |
121 | if (kconsumerd_fds_count > 0) { | |
122 | kconsumerd_fds_count--; | |
123 | if (lcf != NULL) { | |
124 | close(lcf->out_fd); | |
125 | close(lcf->consumerd_fd); | |
126 | free(lcf); | |
127 | lcf = NULL; | |
128 | } | |
129 | } | |
130 | pthread_mutex_unlock(&kconsumerd_lock_fds); | |
131 | } | |
132 | ||
133 | /* | |
134 | * kconsumerd_add_fd | |
135 | * | |
136 | * Add a fd to the global list protected by a mutex | |
137 | */ | |
138 | static int kconsumerd_add_fd(struct lttcomm_kconsumerd_msg *buf, int consumerd_fd) | |
139 | { | |
1ce86c9a | 140 | int ret; |
38079a1b DG |
141 | struct kconsumerd_fd *tmp_fd; |
142 | ||
143 | /* Check if already exist */ | |
144 | ret = kconsumerd_find_session_fd(buf->fd); | |
145 | if (ret == 1) { | |
146 | goto end; | |
147 | } | |
1ce86c9a JD |
148 | |
149 | tmp_fd = malloc(sizeof(struct kconsumerd_fd)); | |
150 | tmp_fd->sessiond_fd = buf->fd; | |
151 | tmp_fd->consumerd_fd = consumerd_fd; | |
152 | tmp_fd->state = buf->state; | |
153 | tmp_fd->max_sb_size = buf->max_sb_size; | |
154 | strncpy(tmp_fd->path_name, buf->path_name, PATH_MAX); | |
155 | ||
156 | /* Opening the tracefile in write mode */ | |
157 | ret = open(tmp_fd->path_name, | |
158 | O_WRONLY|O_CREAT|O_TRUNC, S_IRWXU|S_IRWXG|S_IRWXO); | |
159 | if (ret < 0) { | |
160 | ERR("Opening %s", tmp_fd->path_name); | |
161 | perror("open"); | |
162 | goto end; | |
163 | } | |
164 | tmp_fd->out_fd = ret; | |
165 | tmp_fd->out_fd_offset = 0; | |
166 | ||
167 | DBG("Adding %s (%d, %d, %d)", tmp_fd->path_name, | |
168 | tmp_fd->sessiond_fd, tmp_fd->consumerd_fd, tmp_fd->out_fd); | |
169 | ||
170 | pthread_mutex_lock(&kconsumerd_lock_fds); | |
171 | cds_list_add(&tmp_fd->list, &kconsumerd_fd_list.head); | |
172 | kconsumerd_fds_count++; | |
173 | pthread_mutex_unlock(&kconsumerd_lock_fds); | |
174 | ||
175 | end: | |
176 | return ret; | |
177 | } | |
178 | ||
179 | /* | |
180 | * kconsumerd_change_fd_state | |
181 | * | |
182 | * Update a fd according to what we just received | |
183 | */ | |
184 | static void kconsumerd_change_fd_state(int sessiond_fd, | |
185 | enum kconsumerd_fd_state state) | |
186 | { | |
187 | struct kconsumerd_fd *iter; | |
188 | cds_list_for_each_entry(iter, &kconsumerd_fd_list.head, list) { | |
189 | if (iter->sessiond_fd == sessiond_fd) { | |
190 | iter->state = state; | |
191 | break; | |
192 | } | |
193 | } | |
194 | } | |
195 | ||
196 | /* | |
197 | * kconsumerd_update_poll_array | |
198 | * | |
199 | * Allocate the pollfd structure and the local view of the out fds | |
200 | * to avoid doing a lookup in the linked list and concurrency issues | |
201 | * when writing is needed. | |
202 | * Returns the number of fds in the structures | |
203 | */ | |
204 | static int kconsumerd_update_poll_array(struct pollfd **pollfd, | |
205 | struct kconsumerd_fd **local_kconsumerd_fd) | |
206 | { | |
207 | struct kconsumerd_fd *iter; | |
208 | int i = 0; | |
209 | ||
210 | DBG("Updating poll fd array"); | |
211 | pthread_mutex_lock(&kconsumerd_lock_fds); | |
212 | ||
213 | cds_list_for_each_entry(iter, &kconsumerd_fd_list.head, list) { | |
214 | DBG("Inside for each"); | |
215 | if (iter->state == ACTIVE_FD) { | |
216 | DBG("Active FD %d", iter->consumerd_fd); | |
217 | (*pollfd)[i].fd = iter->consumerd_fd; | |
218 | (*pollfd)[i].events = POLLIN | POLLPRI; | |
219 | local_kconsumerd_fd[i] = iter; | |
220 | i++; | |
221 | } | |
222 | } | |
223 | ||
224 | /* | |
225 | * insert the kconsumerd_poll_pipe at the end of the array and don't | |
226 | * increment i so nb_fd is the number of real FD | |
227 | */ | |
228 | (*pollfd)[i].fd = kconsumerd_poll_pipe[0]; | |
229 | (*pollfd)[i].events = POLLIN; | |
230 | ||
231 | kconsumerd_update_fd_array = 0; | |
232 | pthread_mutex_unlock(&kconsumerd_lock_fds); | |
233 | return i; | |
234 | } | |
235 | ||
236 | ||
237 | /* | |
238 | * kconsumerd_on_read_subbuffer_mmap | |
239 | * | |
240 | * mmap the ring buffer, read it and write the data to the tracefile. | |
241 | * Returns the number of bytes written | |
242 | */ | |
243 | static int kconsumerd_on_read_subbuffer_mmap( | |
244 | struct kconsumerd_fd *kconsumerd_fd, unsigned long len) | |
245 | { | |
246 | unsigned long mmap_len, mmap_offset, padded_len, padding_len; | |
247 | char *mmap_base; | |
248 | char *padding = NULL; | |
249 | long ret = 0; | |
250 | off_t orig_offset = kconsumerd_fd->out_fd_offset; | |
251 | int fd = kconsumerd_fd->consumerd_fd; | |
252 | int outfd = kconsumerd_fd->out_fd; | |
253 | ||
254 | /* get the padded subbuffer size to know the padding required */ | |
255 | ret = kernctl_get_padded_subbuf_size(fd, &padded_len); | |
256 | if (ret != 0) { | |
257 | ret = errno; | |
258 | perror("kernctl_get_padded_subbuf_size"); | |
259 | goto end; | |
260 | } | |
261 | padding_len = padded_len - len; | |
262 | padding = malloc(padding_len * sizeof(char)); | |
263 | memset(padding, '\0', padding_len); | |
264 | ||
265 | /* get the len of the mmap region */ | |
266 | ret = kernctl_get_mmap_len(fd, &mmap_len); | |
267 | if (ret != 0) { | |
268 | ret = errno; | |
269 | perror("kernctl_get_mmap_len"); | |
270 | goto end; | |
271 | } | |
272 | ||
273 | /* get the offset inside the fd to mmap */ | |
274 | ret = kernctl_get_mmap_read_offset(fd, &mmap_offset); | |
275 | if (ret != 0) { | |
276 | ret = errno; | |
277 | perror("kernctl_get_mmap_read_offset"); | |
278 | goto end; | |
279 | } | |
280 | ||
281 | mmap_base = mmap(NULL, mmap_len, PROT_READ, MAP_PRIVATE, fd, mmap_offset); | |
282 | if (mmap_base == MAP_FAILED) { | |
283 | perror("Error mmaping"); | |
284 | ret = -1; | |
285 | goto end; | |
286 | } | |
287 | ||
288 | while (len > 0) { | |
289 | ret = write(outfd, mmap_base, len); | |
290 | if (ret >= len) { | |
291 | len = 0; | |
292 | } else if (ret < 0) { | |
293 | ret = errno; | |
294 | perror("Error in file write"); | |
295 | goto end; | |
296 | } | |
297 | /* This won't block, but will start writeout asynchronously */ | |
298 | sync_file_range(outfd, kconsumerd_fd->out_fd_offset, ret, | |
299 | SYNC_FILE_RANGE_WRITE); | |
300 | kconsumerd_fd->out_fd_offset += ret; | |
301 | } | |
302 | ||
303 | /* once all the data is written, write the padding to disk */ | |
304 | ret = write(outfd, padding, padding_len); | |
305 | if (ret < 0) { | |
306 | ret = errno; | |
307 | perror("Error writing padding to file"); | |
308 | goto end; | |
309 | } | |
310 | ||
311 | /* | |
312 | * This does a blocking write-and-wait on any page that belongs to the | |
313 | * subbuffer prior to the one we just wrote. | |
314 | * Don't care about error values, as these are just hints and ways to | |
315 | * limit the amount of page cache used. | |
316 | */ | |
317 | if (orig_offset >= kconsumerd_fd->max_sb_size) { | |
318 | sync_file_range(outfd, orig_offset - kconsumerd_fd->max_sb_size, | |
319 | kconsumerd_fd->max_sb_size, | |
320 | SYNC_FILE_RANGE_WAIT_BEFORE | |
321 | | SYNC_FILE_RANGE_WRITE | |
322 | | SYNC_FILE_RANGE_WAIT_AFTER); | |
323 | ||
324 | /* | |
325 | * Give hints to the kernel about how we access the file: | |
326 | * POSIX_FADV_DONTNEED : we won't re-access data in a near future after | |
327 | * we write it. | |
328 | * | |
329 | * We need to call fadvise again after the file grows because the | |
330 | * kernel does not seem to apply fadvise to non-existing parts of the | |
331 | * file. | |
332 | * | |
333 | * Call fadvise _after_ having waited for the page writeback to | |
334 | * complete because the dirty page writeback semantic is not well | |
335 | * defined. So it can be expected to lead to lower throughput in | |
336 | * streaming. | |
337 | */ | |
338 | posix_fadvise(outfd, orig_offset - kconsumerd_fd->max_sb_size, | |
339 | kconsumerd_fd->max_sb_size, POSIX_FADV_DONTNEED); | |
340 | } | |
341 | goto end; | |
342 | ||
343 | end: | |
344 | if (padding != NULL) { | |
345 | free(padding); | |
346 | } | |
347 | return ret; | |
348 | } | |
349 | ||
350 | /* | |
351 | * kconsumerd_on_read_subbuffer | |
352 | * | |
353 | * Splice the data from the ring buffer to the tracefile. | |
354 | * Returns the number of bytes spliced | |
355 | */ | |
356 | static int kconsumerd_on_read_subbuffer( | |
357 | struct kconsumerd_fd *kconsumerd_fd, unsigned long len) | |
358 | { | |
359 | long ret = 0; | |
360 | loff_t offset = 0; | |
361 | off_t orig_offset = kconsumerd_fd->out_fd_offset; | |
362 | int fd = kconsumerd_fd->consumerd_fd; | |
363 | int outfd = kconsumerd_fd->out_fd; | |
364 | ||
365 | while (len > 0) { | |
366 | DBG("splice chan to pipe offset %lu (fd : %d)", | |
367 | (unsigned long)offset, fd); | |
368 | ret = splice(fd, &offset, kconsumerd_thread_pipe[1], NULL, len, | |
369 | SPLICE_F_MOVE | SPLICE_F_MORE); | |
370 | DBG("splice chan to pipe ret %ld", ret); | |
371 | if (ret < 0) { | |
372 | ret = errno; | |
373 | perror("Error in relay splice"); | |
374 | goto splice_error; | |
375 | } | |
376 | ||
377 | ret = splice(kconsumerd_thread_pipe[0], NULL, outfd, NULL, ret, | |
378 | SPLICE_F_MOVE | SPLICE_F_MORE); | |
379 | DBG("splice pipe to file %ld", ret); | |
380 | if (ret < 0) { | |
381 | ret = errno; | |
382 | perror("Error in file splice"); | |
383 | goto splice_error; | |
384 | } | |
385 | if (ret >= len) { | |
386 | len = 0; | |
387 | } | |
388 | /* This won't block, but will start writeout asynchronously */ | |
389 | sync_file_range(outfd, kconsumerd_fd->out_fd_offset, ret, | |
390 | SYNC_FILE_RANGE_WRITE); | |
391 | kconsumerd_fd->out_fd_offset += ret; | |
392 | } | |
393 | ||
394 | /* | |
395 | * This does a blocking write-and-wait on any page that belongs to the | |
396 | * subbuffer prior to the one we just wrote. | |
397 | * Don't care about error values, as these are just hints and ways to | |
398 | * limit the amount of page cache used. | |
399 | */ | |
400 | if (orig_offset >= kconsumerd_fd->max_sb_size) { | |
401 | sync_file_range(outfd, orig_offset - kconsumerd_fd->max_sb_size, | |
402 | kconsumerd_fd->max_sb_size, | |
403 | SYNC_FILE_RANGE_WAIT_BEFORE | |
404 | | SYNC_FILE_RANGE_WRITE | |
405 | | SYNC_FILE_RANGE_WAIT_AFTER); | |
406 | /* | |
407 | * Give hints to the kernel about how we access the file: | |
408 | * POSIX_FADV_DONTNEED : we won't re-access data in a near future after | |
409 | * we write it. | |
410 | * | |
411 | * We need to call fadvise again after the file grows because the | |
412 | * kernel does not seem to apply fadvise to non-existing parts of the | |
413 | * file. | |
414 | * | |
415 | * Call fadvise _after_ having waited for the page writeback to | |
416 | * complete because the dirty page writeback semantic is not well | |
417 | * defined. So it can be expected to lead to lower throughput in | |
418 | * streaming. | |
419 | */ | |
420 | posix_fadvise(outfd, orig_offset - kconsumerd_fd->max_sb_size, | |
421 | kconsumerd_fd->max_sb_size, POSIX_FADV_DONTNEED); | |
422 | } | |
423 | goto end; | |
424 | ||
425 | splice_error: | |
426 | /* send the appropriate error description to sessiond */ | |
427 | switch(ret) { | |
428 | case EBADF: | |
429 | kconsumerd_send_error(KCONSUMERD_SPLICE_EBADF); | |
430 | break; | |
431 | case EINVAL: | |
432 | kconsumerd_send_error(KCONSUMERD_SPLICE_EINVAL); | |
433 | break; | |
434 | case ENOMEM: | |
435 | kconsumerd_send_error(KCONSUMERD_SPLICE_ENOMEM); | |
436 | break; | |
437 | case ESPIPE: | |
438 | kconsumerd_send_error(KCONSUMERD_SPLICE_ESPIPE); | |
439 | break; | |
440 | } | |
441 | ||
442 | end: | |
443 | return ret; | |
444 | } | |
445 | ||
446 | /* | |
447 | * kconsumerd_read_subbuffer | |
448 | * | |
449 | * Consume data on a file descriptor and write it on a trace file | |
450 | */ | |
451 | static int kconsumerd_read_subbuffer(struct kconsumerd_fd *kconsumerd_fd) | |
452 | { | |
453 | unsigned long len; | |
454 | int err; | |
455 | long ret = 0; | |
456 | int infd = kconsumerd_fd->consumerd_fd; | |
457 | ||
458 | DBG("In kconsumerd_read_subbuffer (infd : %d)", infd); | |
459 | /* Get the next subbuffer */ | |
460 | err = kernctl_get_next_subbuf(infd); | |
461 | if (err != 0) { | |
462 | ret = errno; | |
463 | perror("Reserving sub buffer failed (everything is normal, " | |
464 | "it is due to concurrency)"); | |
465 | goto end; | |
466 | } | |
467 | ||
468 | switch (DEFAULT_KERNEL_CHANNEL_OUTPUT) { | |
469 | case LTTNG_KERNEL_SPLICE: | |
470 | /* read the whole subbuffer */ | |
471 | err = kernctl_get_padded_subbuf_size(infd, &len); | |
472 | if (err != 0) { | |
473 | ret = errno; | |
474 | perror("Getting sub-buffer len failed."); | |
475 | goto end; | |
476 | } | |
477 | ||
478 | /* splice the subbuffer to the tracefile */ | |
479 | ret = kconsumerd_on_read_subbuffer(kconsumerd_fd, len); | |
480 | if (ret < 0) { | |
481 | /* | |
482 | * display the error but continue processing to try | |
483 | * to release the subbuffer | |
484 | */ | |
485 | ERR("Error splicing to tracefile"); | |
486 | } | |
487 | break; | |
488 | case LTTNG_KERNEL_MMAP: | |
489 | /* read the used subbuffer size */ | |
490 | err = kernctl_get_subbuf_size(infd, &len); | |
491 | if (err != 0) { | |
492 | ret = errno; | |
493 | perror("Getting sub-buffer len failed."); | |
494 | goto end; | |
495 | } | |
496 | /* write the subbuffer to the tracefile */ | |
497 | ret = kconsumerd_on_read_subbuffer_mmap(kconsumerd_fd, len); | |
498 | if (ret < 0) { | |
499 | /* | |
500 | * display the error but continue processing to try | |
501 | * to release the subbuffer | |
502 | */ | |
503 | ERR("Error writing to tracefile"); | |
504 | } | |
505 | break; | |
506 | default: | |
507 | ERR("Unknown output method"); | |
508 | ret = -1; | |
509 | } | |
510 | ||
511 | err = kernctl_put_next_subbuf(infd); | |
512 | if (err != 0) { | |
513 | ret = errno; | |
514 | if (errno == EFAULT) { | |
515 | perror("Error in unreserving sub buffer\n"); | |
516 | } else if (errno == EIO) { | |
517 | /* Should never happen with newer LTTng versions */ | |
518 | perror("Reader has been pushed by the writer, last sub-buffer corrupted."); | |
519 | } | |
520 | goto end; | |
521 | } | |
522 | ||
523 | end: | |
524 | return ret; | |
525 | } | |
526 | ||
527 | /* | |
528 | * kconsumerd_consumerd_recv_fd | |
529 | * | |
530 | * Receives an array of file descriptors and the associated | |
531 | * structures describing each fd (path name). | |
532 | * Returns the size of received data | |
533 | */ | |
534 | static int kconsumerd_consumerd_recv_fd(int sfd, int size, | |
535 | enum kconsumerd_command cmd_type) | |
536 | { | |
537 | struct msghdr msg; | |
538 | struct iovec iov[1]; | |
539 | int ret = 0, i, tmp2; | |
540 | struct cmsghdr *cmsg; | |
541 | int nb_fd; | |
542 | char recv_fd[CMSG_SPACE(sizeof(int))]; | |
543 | struct lttcomm_kconsumerd_msg lkm; | |
544 | ||
545 | /* the number of fds we are about to receive */ | |
546 | nb_fd = size / sizeof(struct lttcomm_kconsumerd_msg); | |
547 | ||
548 | for (i = 0; i < nb_fd; i++) { | |
549 | memset(&msg, 0, sizeof(msg)); | |
550 | ||
551 | /* Prepare to receive the structures */ | |
552 | iov[0].iov_base = &lkm; | |
553 | iov[0].iov_len = sizeof(lkm); | |
554 | msg.msg_iov = iov; | |
555 | msg.msg_iovlen = 1; | |
556 | ||
557 | msg.msg_control = recv_fd; | |
558 | msg.msg_controllen = sizeof(recv_fd); | |
559 | ||
560 | DBG("Waiting to receive fd"); | |
561 | if ((ret = recvmsg(sfd, &msg, 0)) < 0) { | |
562 | perror("recvmsg"); | |
563 | continue; | |
564 | } | |
565 | ||
566 | if (ret != (size / nb_fd)) { | |
567 | ERR("Received only %d, expected %d", ret, size); | |
568 | kconsumerd_send_error(KCONSUMERD_ERROR_RECV_FD); | |
569 | goto end; | |
570 | } | |
571 | ||
572 | cmsg = CMSG_FIRSTHDR(&msg); | |
573 | if (!cmsg) { | |
574 | ERR("Invalid control message header"); | |
575 | ret = -1; | |
576 | kconsumerd_send_error(KCONSUMERD_ERROR_RECV_FD); | |
577 | goto end; | |
578 | } | |
579 | /* if we received fds */ | |
580 | if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) { | |
581 | switch (cmd_type) { | |
582 | case ADD_STREAM: | |
583 | DBG("kconsumerd_add_fd %s (%d)", lkm.path_name, (CMSG_DATA(cmsg)[0])); | |
584 | ret = kconsumerd_add_fd(&lkm, (CMSG_DATA(cmsg)[0])); | |
585 | if (ret < 0) { | |
586 | kconsumerd_send_error(KCONSUMERD_OUTFD_ERROR); | |
587 | goto end; | |
588 | } | |
589 | break; | |
590 | case UPDATE_STREAM: | |
591 | kconsumerd_change_fd_state(lkm.fd, lkm.state); | |
592 | break; | |
593 | default: | |
594 | break; | |
595 | } | |
596 | /* flag to tell the polling thread to update its fd array */ | |
597 | kconsumerd_update_fd_array = 1; | |
598 | /* signal the poll thread */ | |
599 | tmp2 = write(kconsumerd_poll_pipe[1], "4", 1); | |
600 | } else { | |
601 | ERR("Didn't received any fd"); | |
602 | kconsumerd_send_error(KCONSUMERD_ERROR_RECV_FD); | |
603 | ret = -1; | |
604 | goto end; | |
605 | } | |
606 | } | |
607 | ||
608 | end: | |
1ce86c9a JD |
609 | return ret; |
610 | } | |
611 | ||
612 | /* | |
613 | * kconsumerd_thread_poll_fds | |
614 | * | |
615 | * This thread polls the fds in the ltt_fd_list to consume the data | |
616 | * and write it to tracefile if necessary. | |
617 | */ | |
618 | void *kconsumerd_thread_poll_fds(void *data) | |
619 | { | |
620 | int num_rdy, num_hup, high_prio, ret, i; | |
621 | struct pollfd *pollfd = NULL; | |
622 | /* local view of the fds */ | |
623 | struct kconsumerd_fd **local_kconsumerd_fd = NULL; | |
624 | /* local view of kconsumerd_fds_count */ | |
625 | int nb_fd = 0; | |
626 | char tmp; | |
627 | int tmp2; | |
628 | ||
629 | ret = pipe(kconsumerd_thread_pipe); | |
630 | if (ret < 0) { | |
631 | perror("Error creating pipe"); | |
632 | goto end; | |
633 | } | |
634 | ||
635 | local_kconsumerd_fd = malloc(sizeof(struct kconsumerd_fd)); | |
636 | ||
637 | while (1) { | |
638 | high_prio = 0; | |
639 | num_hup = 0; | |
640 | ||
641 | /* | |
642 | * the ltt_fd_list has been updated, we need to update our | |
643 | * local array as well | |
644 | */ | |
645 | if (kconsumerd_update_fd_array == 1) { | |
646 | if (pollfd != NULL) { | |
647 | free(pollfd); | |
648 | pollfd = NULL; | |
649 | } | |
650 | if (local_kconsumerd_fd != NULL) { | |
651 | free(local_kconsumerd_fd); | |
652 | local_kconsumerd_fd = NULL; | |
653 | } | |
654 | /* allocate for all fds + 1 for the kconsumerd_poll_pipe */ | |
655 | pollfd = malloc((kconsumerd_fds_count + 1) * sizeof(struct pollfd)); | |
656 | if (pollfd == NULL) { | |
657 | perror("pollfd malloc"); | |
658 | goto end; | |
659 | } | |
660 | /* allocate for all fds + 1 for the kconsumerd_poll_pipe */ | |
661 | local_kconsumerd_fd = malloc((kconsumerd_fds_count + 1) * | |
662 | sizeof(struct kconsumerd_fd)); | |
663 | if (local_kconsumerd_fd == NULL) { | |
664 | perror("local_kconsumerd_fd malloc"); | |
665 | goto end; | |
666 | } | |
667 | ret = kconsumerd_update_poll_array(&pollfd, local_kconsumerd_fd); | |
668 | if (ret < 0) { | |
669 | ERR("Error in allocating pollfd or local_outfds"); | |
670 | kconsumerd_send_error(KCONSUMERD_POLL_ERROR); | |
671 | goto end; | |
672 | } | |
673 | nb_fd = ret; | |
674 | } | |
675 | ||
676 | /* poll on the array of fds */ | |
677 | DBG("polling on %d fd", nb_fd + 1); | |
678 | num_rdy = poll(pollfd, nb_fd + 1, kconsumerd_poll_timeout); | |
679 | DBG("poll num_rdy : %d", num_rdy); | |
680 | if (num_rdy == -1) { | |
681 | perror("Poll error"); | |
682 | kconsumerd_send_error(KCONSUMERD_POLL_ERROR); | |
683 | goto end; | |
684 | } else if (num_rdy == 0) { | |
685 | DBG("Polling thread timed out"); | |
686 | goto end; | |
687 | } | |
688 | ||
689 | /* No FDs and kconsumerd_quit, kconsumerd_cleanup the thread */ | |
690 | if (nb_fd == 0 && kconsumerd_quit == 1) { | |
691 | goto end; | |
692 | } | |
693 | ||
694 | /* | |
695 | * if only the kconsumerd_poll_pipe triggered poll to return just | |
696 | * return to the beginning of the loop to update the array | |
697 | */ | |
698 | if (num_rdy == 1 && pollfd[nb_fd].revents == POLLIN) { | |
699 | DBG("kconsumerd_poll_pipe wake up"); | |
700 | tmp2 = read(kconsumerd_poll_pipe[0], &tmp, 1); | |
701 | continue; | |
702 | } | |
703 | ||
704 | /* Take care of high priority channels first. */ | |
705 | for (i = 0; i < nb_fd; i++) { | |
706 | switch(pollfd[i].revents) { | |
707 | case POLLERR: | |
708 | ERR("Error returned in polling fd %d.", pollfd[i].fd); | |
709 | kconsumerd_del_fd(local_kconsumerd_fd[i]); | |
710 | kconsumerd_update_fd_array = 1; | |
711 | num_hup++; | |
712 | break; | |
713 | case POLLHUP: | |
714 | DBG("Polling fd %d tells it has hung up.", pollfd[i].fd); | |
715 | kconsumerd_del_fd(local_kconsumerd_fd[i]); | |
716 | kconsumerd_update_fd_array = 1; | |
717 | num_hup++; | |
718 | break; | |
719 | case POLLNVAL: | |
720 | ERR("Polling fd %d tells fd is not open.", pollfd[i].fd); | |
721 | kconsumerd_del_fd(local_kconsumerd_fd[i]); | |
722 | kconsumerd_update_fd_array = 1; | |
723 | num_hup++; | |
724 | break; | |
725 | case POLLPRI: | |
726 | DBG("Urgent read on fd %d", pollfd[i].fd); | |
727 | high_prio = 1; | |
728 | ret = kconsumerd_read_subbuffer(local_kconsumerd_fd[i]); | |
729 | /* it's ok to have an unavailable sub-buffer */ | |
730 | if (ret == EAGAIN) { | |
731 | ret = 0; | |
732 | } | |
733 | break; | |
734 | } | |
735 | } | |
736 | ||
737 | /* If every buffer FD has hung up, we end the read loop here */ | |
738 | if (nb_fd > 0 && num_hup == nb_fd) { | |
739 | DBG("every buffer FD has hung up\n"); | |
740 | if (kconsumerd_quit == 1) { | |
741 | goto end; | |
742 | } | |
743 | continue; | |
744 | } | |
745 | ||
746 | /* Take care of low priority channels. */ | |
747 | if (high_prio == 0) { | |
748 | for (i = 0; i < nb_fd; i++) { | |
749 | if (pollfd[i].revents == POLLIN) { | |
750 | DBG("Normal read on fd %d", pollfd[i].fd); | |
751 | ret = kconsumerd_read_subbuffer(local_kconsumerd_fd[i]); | |
752 | /* it's ok to have an unavailable subbuffer */ | |
753 | if (ret == EAGAIN) { | |
754 | ret = 0; | |
755 | } | |
756 | } | |
757 | } | |
758 | } | |
759 | } | |
760 | end: | |
761 | DBG("polling thread exiting"); | |
762 | if (pollfd != NULL) { | |
763 | free(pollfd); | |
764 | pollfd = NULL; | |
765 | } | |
766 | if (local_kconsumerd_fd != NULL) { | |
767 | free(local_kconsumerd_fd); | |
768 | local_kconsumerd_fd = NULL; | |
769 | } | |
770 | kconsumerd_cleanup(); | |
771 | return NULL; | |
772 | } | |
773 | ||
774 | /* | |
775 | * kconsumerd_create_poll_pipe | |
776 | * | |
777 | * create the pipe to wake to polling thread when needed | |
778 | */ | |
779 | int kconsumerd_create_poll_pipe() | |
780 | { | |
781 | return pipe(kconsumerd_poll_pipe); | |
782 | } | |
783 | ||
784 | /* | |
785 | * kconsumerd_thread_receive_fds | |
786 | * | |
787 | * This thread listens on the consumerd socket and | |
788 | * receives the file descriptors from ltt-sessiond | |
789 | */ | |
790 | void *kconsumerd_thread_receive_fds(void *data) | |
791 | { | |
792 | int sock, client_socket, ret; | |
793 | struct lttcomm_kconsumerd_header tmp; | |
794 | ||
795 | DBG("Creating command socket %s", kconsumerd_command_sock_path); | |
796 | unlink(kconsumerd_command_sock_path); | |
797 | client_socket = lttcomm_create_unix_sock(kconsumerd_command_sock_path); | |
798 | if (client_socket < 0) { | |
799 | ERR("Cannot create command socket"); | |
800 | goto end; | |
801 | } | |
802 | ||
803 | ret = lttcomm_listen_unix_sock(client_socket); | |
804 | if (ret < 0) { | |
805 | goto end; | |
806 | } | |
807 | ||
808 | DBG("Sending ready command to ltt-sessiond"); | |
809 | ret = kconsumerd_send_error(KCONSUMERD_COMMAND_SOCK_READY); | |
810 | if (ret < 0) { | |
811 | ERR("Error sending ready command to ltt-sessiond"); | |
812 | goto end; | |
813 | } | |
814 | ||
815 | /* Blocking call, waiting for transmission */ | |
816 | sock = lttcomm_accept_unix_sock(client_socket); | |
817 | if (sock <= 0) { | |
818 | WARN("On accept"); | |
819 | goto end; | |
820 | } | |
821 | while (1) { | |
822 | /* We first get the number of fd we are about to receive */ | |
823 | ret = lttcomm_recv_unix_sock(sock, &tmp, | |
824 | sizeof(struct lttcomm_kconsumerd_header)); | |
825 | if (ret <= 0) { | |
826 | ERR("Communication interrupted on command socket"); | |
827 | goto end; | |
828 | } | |
829 | if (tmp.cmd_type == STOP) { | |
830 | DBG("Received STOP command"); | |
831 | goto end; | |
832 | } | |
833 | /* we received a command to add or update fds */ | |
834 | ret = kconsumerd_consumerd_recv_fd(sock, tmp.payload_size, tmp.cmd_type); | |
835 | if (ret <= 0) { | |
836 | ERR("Receiving the FD, exiting"); | |
837 | goto end; | |
838 | } | |
839 | } | |
840 | ||
841 | end: | |
842 | DBG("kconsumerd_thread_receive_fds exiting"); | |
843 | ||
844 | /* | |
845 | * when all fds have hung up, the polling thread | |
846 | * can exit cleanly | |
847 | */ | |
848 | kconsumerd_quit = 1; | |
849 | ||
850 | /* | |
851 | * 2s of grace period, if no polling events occur during | |
852 | * this period, the polling thread will exit even if there | |
853 | * are still open FDs (should not happen, but safety mechanism). | |
854 | */ | |
855 | kconsumerd_poll_timeout = KCONSUMERD_POLL_GRACE_PERIOD; | |
856 | ||
857 | /* wake up the polling thread */ | |
858 | ret = write(kconsumerd_poll_pipe[1], "4", 1); | |
859 | if (ret < 0) { | |
860 | perror("poll pipe write"); | |
861 | } | |
862 | return NULL; | |
863 | } | |
864 | ||
865 | /* | |
866 | * kconsumerd_cleanup | |
867 | * | |
868 | * Cleanup the daemon's socket on exit | |
869 | */ | |
870 | void kconsumerd_cleanup() | |
871 | { | |
872 | struct kconsumerd_fd *iter; | |
873 | ||
874 | /* remove the socket file */ | |
875 | unlink(kconsumerd_command_sock_path); | |
876 | ||
877 | /* close all outfd */ | |
878 | cds_list_for_each_entry(iter, &kconsumerd_fd_list.head, list) { | |
879 | kconsumerd_del_fd(iter); | |
880 | } | |
881 | } | |
882 | ||
883 | /* | |
884 | * kconsumerd_send_error | |
885 | * | |
886 | * send return code to ltt-sessiond | |
887 | */ | |
888 | int kconsumerd_send_error(enum lttcomm_return_code cmd) | |
889 | { | |
890 | if (kconsumerd_error_socket > 0) { | |
891 | return lttcomm_send_unix_sock(kconsumerd_error_socket, &cmd, | |
892 | sizeof(enum lttcomm_sessiond_command)); | |
893 | } | |
894 | ||
895 | return 0; | |
896 | } |