Commit | Line | Data |
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d4a1283e 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 <getopt.h> | |
23 | #include <grp.h> | |
24 | #include <limits.h> | |
25 | #include <pthread.h> | |
26 | #include <signal.h> | |
27 | #include <stdio.h> | |
28 | #include <stdlib.h> | |
29 | #include <string.h> | |
30 | #include <sys/ipc.h> | |
31 | #include <sys/shm.h> | |
32 | #include <sys/socket.h> | |
33 | #include <sys/stat.h> | |
34 | #include <sys/types.h> | |
35 | #include <urcu/list.h> | |
36 | #include <poll.h> | |
37 | #include <unistd.h> | |
38 | ||
39 | #include "lttngerr.h" | |
40 | #include "libkernelctl.h" | |
41 | #include "liblttsessiondcomm.h" | |
42 | #include "kconsumerd.h" | |
43 | ||
44 | /* Init the list of FDs */ | |
45 | static struct ltt_kconsumerd_fd_list kconsumerd_fd_list = { | |
46 | .head = CDS_LIST_HEAD_INIT(kconsumerd_fd_list.head), | |
47 | }; | |
48 | ||
49 | /* Number of element for the list below. */ | |
50 | static unsigned int fds_count; | |
51 | ||
52 | /* If the local array of FDs needs update in the poll function */ | |
53 | static unsigned int update_fd_array = 1; | |
54 | ||
55 | /* lock the fd array and structures */ | |
56 | static pthread_mutex_t kconsumerd_lock_fds; | |
57 | ||
58 | /* the two threads (receive fd and poll) */ | |
59 | static pthread_t threads[2]; | |
60 | ||
61 | /* communication with splice */ | |
62 | static int thread_pipe[2]; | |
63 | ||
64 | /* socket to communicate errors with sessiond */ | |
65 | static int error_socket = -1; | |
66 | ||
67 | /* Argument variables */ | |
68 | int opt_quiet; | |
69 | int opt_verbose; | |
70 | static int opt_daemon; | |
71 | static const char *progname; | |
72 | static char command_sock_path[PATH_MAX]; /* Global command socket path */ | |
73 | static char error_sock_path[PATH_MAX]; /* Global error path */ | |
74 | ||
bcd8d9db JD |
75 | /* |
76 | * del_fd | |
77 | * | |
78 | * Remove a fd from the global list protected by a mutex | |
79 | */ | |
80 | static void del_fd(struct ltt_kconsumerd_fd *lcf) | |
81 | { | |
82 | pthread_mutex_lock(&kconsumerd_lock_fds); | |
83 | cds_list_del(&lcf->list); | |
84 | if (fds_count > 0) { | |
85 | fds_count--; | |
86 | DBG("Removed ltt_kconsumerd_fd"); | |
87 | if (lcf != NULL) { | |
88 | close(lcf->out_fd); | |
89 | close(lcf->consumerd_fd); | |
90 | free(lcf); | |
91 | lcf = NULL; | |
92 | } | |
93 | } | |
94 | pthread_mutex_unlock(&kconsumerd_lock_fds); | |
95 | } | |
96 | ||
d4a1283e JD |
97 | /* |
98 | * cleanup | |
99 | * | |
100 | * Cleanup the daemon's socket on exit | |
101 | */ | |
102 | static void cleanup() | |
103 | { | |
bcd8d9db JD |
104 | struct ltt_kconsumerd_fd *iter; |
105 | ||
106 | ||
107 | /* remove the socket file */ | |
d4a1283e | 108 | unlink(command_sock_path); |
bcd8d9db JD |
109 | |
110 | /* unblock the threads */ | |
111 | WARN("Terminating the threads before exiting"); | |
112 | pthread_cancel(threads[0]); | |
113 | pthread_cancel(threads[1]); | |
114 | ||
115 | /* close all outfd */ | |
116 | cds_list_for_each_entry(iter, &kconsumerd_fd_list.head, list) { | |
117 | del_fd(iter); | |
118 | } | |
d4a1283e JD |
119 | } |
120 | ||
121 | /* send_error | |
122 | * | |
123 | * send return code to ltt-sessiond | |
124 | */ | |
125 | static int send_error(enum lttcomm_return_code cmd) | |
126 | { | |
127 | if (error_socket > 0) { | |
128 | return lttcomm_send_unix_sock(error_socket, &cmd, | |
129 | sizeof(enum lttcomm_sessiond_command)); | |
130 | } else { | |
131 | return 0; | |
132 | } | |
133 | } | |
134 | ||
d4a1283e JD |
135 | /* |
136 | * add_fd | |
137 | * | |
138 | * Add a fd to the global list protected by a mutex | |
139 | */ | |
140 | static int add_fd(struct lttcomm_kconsumerd_msg *buf, int consumerd_fd) | |
141 | { | |
142 | struct ltt_kconsumerd_fd *tmp_fd; | |
143 | int ret; | |
144 | ||
145 | tmp_fd = malloc(sizeof(struct ltt_kconsumerd_fd)); | |
146 | tmp_fd->sessiond_fd = buf->fd; | |
147 | tmp_fd->consumerd_fd = consumerd_fd; | |
148 | tmp_fd->state = buf->state; | |
149 | tmp_fd->max_sb_size = buf->max_sb_size; | |
150 | strncpy(tmp_fd->path_name, buf->path_name, PATH_MAX); | |
151 | ||
152 | /* Opening the tracefile in write mode */ | |
153 | DBG("Opening %s for writing", tmp_fd->path_name); | |
154 | ret = open(tmp_fd->path_name, | |
155 | O_WRONLY|O_CREAT, S_IRWXU|S_IRWXG|S_IRWXO); | |
156 | if (ret < 0) { | |
157 | ERR("Opening %s", tmp_fd->path_name); | |
158 | perror("open"); | |
159 | goto end; | |
160 | } | |
161 | tmp_fd->out_fd = ret; | |
162 | tmp_fd->out_fd_offset = 0; | |
163 | ||
164 | DBG("Adding %s (%d, %d, %d)", tmp_fd->path_name, | |
165 | tmp_fd->sessiond_fd, tmp_fd->consumerd_fd, tmp_fd->out_fd); | |
166 | ||
167 | pthread_mutex_lock(&kconsumerd_lock_fds); | |
168 | cds_list_add(&tmp_fd->list, &kconsumerd_fd_list.head); | |
169 | fds_count++; | |
170 | pthread_mutex_unlock(&kconsumerd_lock_fds); | |
171 | ||
172 | end: | |
173 | return ret; | |
174 | } | |
175 | ||
d4a1283e JD |
176 | |
177 | /* | |
178 | * sighandler | |
179 | * | |
180 | * Signal handler for the daemon | |
181 | */ | |
182 | static void sighandler(int sig) | |
183 | { | |
d4a1283e JD |
184 | cleanup(); |
185 | ||
186 | return; | |
187 | } | |
188 | ||
189 | /* | |
190 | * set_signal_handler | |
191 | * | |
192 | * Setup signal handler for : | |
193 | * SIGINT, SIGTERM, SIGPIPE | |
194 | */ | |
195 | static int set_signal_handler(void) | |
196 | { | |
197 | int ret = 0; | |
198 | struct sigaction sa; | |
199 | sigset_t sigset; | |
200 | ||
201 | if ((ret = sigemptyset(&sigset)) < 0) { | |
202 | perror("sigemptyset"); | |
203 | return ret; | |
204 | } | |
205 | ||
206 | sa.sa_handler = sighandler; | |
207 | sa.sa_mask = sigset; | |
208 | sa.sa_flags = 0; | |
209 | if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) { | |
210 | perror("sigaction"); | |
211 | return ret; | |
212 | } | |
213 | ||
214 | if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) { | |
215 | perror("sigaction"); | |
216 | return ret; | |
217 | } | |
218 | ||
219 | if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) { | |
220 | perror("sigaction"); | |
221 | return ret; | |
222 | } | |
223 | ||
224 | return ret; | |
225 | } | |
226 | ||
227 | /* | |
228 | * on_read_subbuffer | |
229 | * | |
230 | * Splice the data from the ring buffer to the tracefile. | |
231 | * Returns the number of bytes spliced | |
232 | */ | |
233 | static int on_read_subbuffer(struct ltt_kconsumerd_fd *kconsumerd_fd, | |
234 | unsigned long len) | |
235 | { | |
236 | long ret = 0; | |
237 | loff_t offset = 0; | |
238 | off_t orig_offset = kconsumerd_fd->out_fd_offset; | |
239 | int fd = kconsumerd_fd->consumerd_fd; | |
240 | int outfd = kconsumerd_fd->out_fd; | |
241 | ||
242 | while (len > 0) { | |
243 | DBG("splice chan to pipe offset %lu (fd : %d)", | |
244 | (unsigned long)offset, fd); | |
245 | ret = splice(fd, &offset, thread_pipe[1], NULL, len, | |
246 | SPLICE_F_MOVE | SPLICE_F_MORE); | |
247 | DBG("splice chan to pipe ret %ld", ret); | |
248 | if (ret < 0) { | |
0632499a | 249 | ret = errno; |
d4a1283e | 250 | perror("Error in relay splice"); |
0632499a | 251 | goto splice_error; |
d4a1283e JD |
252 | } |
253 | ||
254 | ret = splice(thread_pipe[0], NULL, outfd, NULL, ret, | |
255 | SPLICE_F_MOVE | SPLICE_F_MORE); | |
256 | DBG("splice pipe to file %ld", ret); | |
257 | if (ret < 0) { | |
0632499a | 258 | ret = errno; |
d4a1283e | 259 | perror("Error in file splice"); |
0632499a | 260 | goto splice_error; |
d4a1283e JD |
261 | } |
262 | if (ret >= len) { | |
263 | len = 0; | |
264 | } | |
265 | /* This won't block, but will start writeout asynchronously */ | |
266 | sync_file_range(outfd, kconsumerd_fd->out_fd_offset, ret, | |
267 | SYNC_FILE_RANGE_WRITE); | |
268 | kconsumerd_fd->out_fd_offset += ret; | |
269 | } | |
0632499a | 270 | |
d4a1283e JD |
271 | /* |
272 | * This does a blocking write-and-wait on any page that belongs to the | |
273 | * subbuffer prior to the one we just wrote. | |
274 | * Don't care about error values, as these are just hints and ways to | |
275 | * limit the amount of page cache used. | |
276 | */ | |
277 | if (orig_offset >= kconsumerd_fd->max_sb_size) { | |
278 | sync_file_range(outfd, orig_offset - kconsumerd_fd->max_sb_size, | |
279 | kconsumerd_fd->max_sb_size, | |
280 | SYNC_FILE_RANGE_WAIT_BEFORE | |
281 | | SYNC_FILE_RANGE_WRITE | |
282 | | SYNC_FILE_RANGE_WAIT_AFTER); | |
283 | /* | |
284 | * Give hints to the kernel about how we access the file: | |
285 | * POSIX_FADV_DONTNEED : we won't re-access data in a near | |
286 | * future after we write it. | |
287 | * We need to call fadvise again after the file grows because | |
288 | * the kernel does not seem to apply fadvise to non-existing | |
289 | * parts of the file. | |
290 | * Call fadvise _after_ having waited for the page writeback to | |
291 | * complete because the dirty page writeback semantic is not | |
292 | * well defined. So it can be expected to lead to lower | |
293 | * throughput in streaming. | |
294 | */ | |
295 | posix_fadvise(outfd, orig_offset - kconsumerd_fd->max_sb_size, | |
296 | kconsumerd_fd->max_sb_size, POSIX_FADV_DONTNEED); | |
297 | } | |
0632499a JD |
298 | goto end; |
299 | ||
300 | splice_error: | |
301 | /* send the appropriate error description to sessiond */ | |
302 | switch(ret) { | |
303 | case EBADF: | |
304 | send_error(KCONSUMERD_SPLICE_EBADF); | |
305 | break; | |
306 | case EINVAL: | |
307 | send_error(KCONSUMERD_SPLICE_EINVAL); | |
308 | break; | |
309 | case ENOMEM: | |
310 | send_error(KCONSUMERD_SPLICE_ENOMEM); | |
311 | break; | |
312 | case ESPIPE: | |
313 | send_error(KCONSUMERD_SPLICE_ESPIPE); | |
314 | break; | |
315 | } | |
316 | ||
317 | end: | |
d4a1283e JD |
318 | return ret; |
319 | } | |
320 | ||
321 | /* | |
322 | * read_subbuffer | |
323 | * | |
324 | * Consume data on a file descriptor and write it on a trace file | |
325 | */ | |
326 | static int read_subbuffer(struct ltt_kconsumerd_fd *kconsumerd_fd) | |
327 | { | |
328 | unsigned long len; | |
329 | int err; | |
330 | long ret = 0; | |
331 | int infd = kconsumerd_fd->consumerd_fd; | |
332 | ||
333 | DBG("In read_subbuffer"); | |
334 | /* Get the next subbuffer */ | |
335 | err = kernctl_get_next_subbuf(infd); | |
336 | if (err != 0) { | |
337 | ret = errno; | |
338 | perror("Reserving sub buffer failed (everything is normal, " | |
339 | "it is due to concurrency)"); | |
340 | goto end; | |
341 | } | |
342 | ||
343 | /* read the whole subbuffer */ | |
344 | err = kernctl_get_padded_subbuf_size(infd, &len); | |
345 | if (err != 0) { | |
346 | ret = errno; | |
347 | perror("Getting sub-buffer len failed."); | |
348 | goto end; | |
349 | } | |
350 | ||
351 | /* splice the subbuffer to the tracefile */ | |
352 | ret = on_read_subbuffer(kconsumerd_fd, len); | |
353 | if (ret < 0) { | |
354 | /* | |
355 | * display the error but continue processing to try | |
356 | * to release the subbuffer | |
357 | */ | |
358 | ERR("Error splicing to tracefile"); | |
359 | } | |
360 | ||
361 | err = kernctl_put_next_subbuf(infd); | |
362 | if (err != 0) { | |
363 | ret = errno; | |
364 | if (errno == EFAULT) { | |
365 | perror("Error in unreserving sub buffer\n"); | |
366 | } else if (errno == EIO) { | |
367 | /* Should never happen with newer LTTng versions */ | |
368 | perror("Reader has been pushed by the writer, last sub-buffer corrupted."); | |
369 | } | |
370 | goto end; | |
371 | } | |
372 | ||
373 | end: | |
374 | return ret; | |
375 | } | |
376 | ||
377 | /* | |
378 | * change_fd_state | |
379 | * | |
380 | * Update a fd according to what we just received | |
381 | */ | |
382 | static void change_fd_state(int sessiond_fd, | |
383 | enum lttcomm_kconsumerd_fd_state state) | |
384 | { | |
385 | struct ltt_kconsumerd_fd *iter; | |
386 | cds_list_for_each_entry(iter, &kconsumerd_fd_list.head, list) { | |
387 | if (iter->sessiond_fd == sessiond_fd) { | |
388 | iter->state = state; | |
389 | break; | |
390 | } | |
391 | } | |
392 | } | |
393 | ||
394 | /* | |
395 | * consumerd_recv_fd | |
396 | * | |
397 | * Receives an array of file descriptors and the associated | |
398 | * structures describing each fd (path name). | |
399 | * Returns the size of received data | |
400 | */ | |
401 | static int consumerd_recv_fd(int sfd, int size, | |
402 | enum lttcomm_consumerd_command cmd_type) | |
403 | { | |
404 | struct msghdr msg; | |
405 | struct iovec iov[1]; | |
406 | int ret, i; | |
407 | struct cmsghdr *cmsg; | |
408 | int nb_fd; | |
409 | char tmp[CMSG_SPACE(size)]; | |
410 | struct lttcomm_kconsumerd_msg *buf; | |
411 | /* the number of fds we are about to receive */ | |
412 | nb_fd = size/sizeof(struct lttcomm_kconsumerd_msg); | |
413 | ||
414 | buf = malloc(size); | |
415 | ||
416 | memset(&msg, 0, sizeof(msg)); | |
417 | ||
418 | /* Prepare to receive the structures */ | |
419 | iov[0].iov_base = buf; | |
420 | iov[0].iov_len = size; | |
421 | msg.msg_iov = iov; | |
422 | msg.msg_iovlen = 1; | |
423 | ||
424 | msg.msg_control = tmp; | |
425 | msg.msg_controllen = sizeof(tmp); | |
426 | ||
427 | DBG("Waiting to receive fds"); | |
428 | if ((ret = recvmsg(sfd, &msg, 0)) < 0) { | |
429 | perror("recvmsg"); | |
430 | } | |
431 | if (ret != size) { | |
432 | ERR("Received only %d, expected %d", ret, size); | |
433 | send_error(KCONSUMERD_ERROR_RECV_FD); | |
434 | goto end; | |
435 | } | |
436 | ||
437 | cmsg = CMSG_FIRSTHDR(&msg); | |
438 | if (!cmsg) { | |
439 | ERR("Invalid control message header"); | |
440 | ret = -1; | |
441 | send_error(KCONSUMERD_ERROR_RECV_FD); | |
442 | goto end; | |
443 | } | |
444 | ||
445 | /* if we received fds */ | |
446 | if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) { | |
447 | DBG("Receive : expecting %d fds", nb_fd); | |
448 | for (i = 0; i < nb_fd; i++) { | |
449 | switch (cmd_type) { | |
450 | case LTTCOMM_ADD_STREAM: | |
451 | DBG("add_fd %s (%d)", buf[i].path_name, ((int *)CMSG_DATA(cmsg))[i]); | |
452 | ret = add_fd(&buf[i], ((int *)CMSG_DATA(cmsg))[i]); | |
453 | if (ret < 0) { | |
454 | send_error(KCONSUMERD_OUTFD_ERROR); | |
455 | goto end; | |
456 | } | |
457 | break; | |
458 | case LTTCOMM_UPDATE_STREAM: | |
459 | change_fd_state(buf[i].fd, buf[i].state); | |
460 | break; | |
461 | default: | |
462 | break; | |
463 | } | |
464 | } | |
465 | /* flag to tell the polling thread to update its fd array */ | |
466 | update_fd_array = 1; | |
467 | send_error(KCONSUMERD_SUCCESS_RECV_FD); | |
468 | } else { | |
469 | ERR("Didn't received any fd"); | |
470 | send_error(KCONSUMERD_ERROR_RECV_FD); | |
471 | ret = -1; | |
472 | goto end; | |
473 | } | |
474 | ||
475 | end: | |
476 | if (buf != NULL) { | |
477 | free(buf); | |
478 | buf = NULL; | |
479 | } | |
480 | return ret; | |
481 | } | |
482 | ||
483 | /* | |
484 | * thread_receive_fds | |
485 | * | |
486 | * This thread listens on the consumerd socket and | |
487 | * receives the file descriptors from ltt-sessiond | |
488 | */ | |
489 | static void *thread_receive_fds(void *data) | |
490 | { | |
491 | int sock, client_socket, ret; | |
492 | struct lttcomm_kconsumerd_header tmp; | |
493 | ||
494 | DBG("Creating command socket %s", command_sock_path); | |
495 | unlink(command_sock_path); | |
496 | client_socket = lttcomm_create_unix_sock(command_sock_path); | |
497 | if (client_socket < 0) { | |
498 | ERR("Cannot create command socket"); | |
499 | goto error; | |
500 | } | |
501 | ||
502 | ret = lttcomm_listen_unix_sock(client_socket); | |
503 | if (ret < 0) { | |
504 | goto error; | |
505 | } | |
506 | ||
507 | DBG("Sending ready command to ltt-sessiond"); | |
508 | ret = send_error(KCONSUMERD_COMMAND_SOCK_READY); | |
509 | if (ret < 0) { | |
510 | ERR("Error sending ready command to ltt-sessiond"); | |
511 | goto error; | |
512 | } | |
513 | ||
7e8c38c6 JD |
514 | /* Blocking call, waiting for transmission */ |
515 | sock = lttcomm_accept_unix_sock(client_socket); | |
516 | if (sock <= 0) { | |
517 | WARN("On accept, retrying"); | |
518 | goto error; | |
519 | } | |
d4a1283e | 520 | while (1) { |
d4a1283e JD |
521 | |
522 | /* We first get the number of fd we are about to receive */ | |
523 | ret = lttcomm_recv_unix_sock(sock, &tmp, | |
524 | sizeof(struct lttcomm_kconsumerd_header)); | |
525 | if (ret < 0) { | |
bcd8d9db JD |
526 | ERR("Receiving the lttcomm_kconsumerd_header, exiting"); |
527 | goto error; | |
d4a1283e JD |
528 | } |
529 | ret = consumerd_recv_fd(sock, tmp.payload_size, tmp.cmd_type); | |
530 | if (ret < 0) { | |
bcd8d9db JD |
531 | ERR("Receiving the FD, exiting"); |
532 | goto error; | |
d4a1283e JD |
533 | } |
534 | } | |
535 | ||
536 | error: | |
bcd8d9db | 537 | cleanup(); |
d4a1283e JD |
538 | return NULL; |
539 | } | |
540 | ||
541 | /* | |
542 | * update_poll_array | |
543 | * | |
544 | * Allocate the pollfd structure and the local view of the out fds | |
545 | * to avoid doing a lookup in the linked list and concurrency issues | |
546 | * when writing is needed. | |
547 | * Returns the number of fds in the structures | |
548 | */ | |
549 | static int update_poll_array(struct pollfd **pollfd, | |
550 | struct ltt_kconsumerd_fd **local_kconsumerd_fd) | |
551 | { | |
552 | struct ltt_kconsumerd_fd *iter; | |
553 | int i = 0; | |
554 | ||
555 | if (*pollfd != NULL) { | |
556 | free(*pollfd); | |
557 | *pollfd = NULL; | |
558 | } | |
559 | ||
560 | if (*local_kconsumerd_fd != NULL) { | |
561 | free(*local_kconsumerd_fd); | |
562 | *local_kconsumerd_fd = NULL; | |
563 | } | |
564 | ||
565 | *pollfd = malloc(fds_count * sizeof(struct pollfd)); | |
566 | if (*pollfd == NULL) { | |
567 | perror("pollfd malloc"); | |
568 | goto error_mem; | |
569 | } | |
570 | ||
571 | *local_kconsumerd_fd = malloc(fds_count * sizeof(struct ltt_kconsumerd_fd)); | |
572 | if (*local_kconsumerd_fd == NULL) { | |
573 | perror("local_kconsumerd_fd malloc"); | |
574 | goto error_mem; | |
575 | } | |
576 | ||
577 | DBG("Updating poll fd array"); | |
578 | pthread_mutex_lock(&kconsumerd_lock_fds); | |
579 | ||
580 | cds_list_for_each_entry(iter, &kconsumerd_fd_list.head, list) { | |
581 | DBG("Inside for each"); | |
582 | if (iter->state == ACTIVE_FD) { | |
583 | DBG("Active FD %d", iter->consumerd_fd); | |
1b686c3f JD |
584 | (*pollfd)[i].fd = iter->consumerd_fd; |
585 | (*pollfd)[i].events = POLLIN | POLLPRI; | |
d4a1283e JD |
586 | local_kconsumerd_fd[i] = iter; |
587 | i++; | |
588 | } else if (iter->state == DELETE_FD) { | |
589 | del_fd(iter); | |
590 | } | |
591 | } | |
592 | update_fd_array = 0; | |
593 | pthread_mutex_unlock(&kconsumerd_lock_fds); | |
594 | return i; | |
595 | ||
596 | error_mem: | |
597 | return -ENOMEM; | |
598 | } | |
599 | ||
600 | /* | |
601 | * thread_poll_fds | |
602 | * | |
603 | * This thread polls the fds in the ltt_fd_list to consume the data | |
604 | * and write it to tracefile if necessary. | |
605 | */ | |
606 | static void *thread_poll_fds(void *data) | |
607 | { | |
608 | int num_rdy, num_hup, high_prio, ret, i; | |
609 | struct pollfd *pollfd = NULL; | |
610 | /* local view of the fds */ | |
611 | struct ltt_kconsumerd_fd *local_kconsumerd_fd = NULL; | |
612 | /* local view of fds_count */ | |
613 | int nb_fd = 0; | |
614 | ||
615 | ret = pipe(thread_pipe); | |
616 | if (ret < 0) { | |
617 | perror("Error creating pipe"); | |
618 | goto end; | |
619 | } | |
620 | ||
621 | while (1) { | |
622 | high_prio = 0; | |
623 | num_hup = 0; | |
624 | ||
625 | /* | |
626 | * the ltt_fd_list has been updated, we need to update our | |
627 | * local array as well | |
628 | */ | |
629 | if (update_fd_array) { | |
630 | ret = update_poll_array(&pollfd, &local_kconsumerd_fd); | |
631 | if (ret < 0) { | |
632 | ERR("Error in allocating pollfd or local_outfds"); | |
633 | send_error(KCONSUMERD_POLL_ERROR); | |
634 | goto end; | |
635 | } | |
636 | nb_fd = ret; | |
637 | } | |
638 | ||
639 | /* poll on the array of fds */ | |
640 | DBG("polling on %d fd", nb_fd); | |
641 | num_rdy = poll(pollfd, nb_fd, POLL_TIMEOUT); | |
642 | DBG("poll num_rdy : %d", num_rdy); | |
643 | if (num_rdy == -1) { | |
644 | perror("Poll error"); | |
645 | send_error(KCONSUMERD_POLL_ERROR); | |
646 | goto end; | |
647 | } | |
648 | ||
649 | /* Take care of high priority channels first. */ | |
650 | for (i = 0; i < nb_fd; i++) { | |
651 | switch(pollfd[i].revents) { | |
652 | case POLLERR: | |
653 | ERR("Error returned in polling fd %d.", pollfd[i].fd); | |
654 | num_hup++; | |
655 | send_error(KCONSUMERD_POLL_ERROR); | |
656 | break; | |
657 | case POLLHUP: | |
658 | ERR("Polling fd %d tells it has hung up.", pollfd[i].fd); | |
659 | num_hup++; | |
660 | break; | |
661 | case POLLNVAL: | |
662 | ERR("Polling fd %d tells fd is not open.", pollfd[i].fd); | |
663 | send_error(KCONSUMERD_POLL_NVAL); | |
664 | num_hup++; | |
665 | break; | |
666 | case POLLPRI: | |
667 | DBG("Urgent read on fd %d", pollfd[i].fd); | |
668 | high_prio = 1; | |
669 | ret = read_subbuffer(&local_kconsumerd_fd[i]); | |
670 | /* it's ok to have an unavailable sub-buffer (FIXME : is it ?) */ | |
671 | if (ret == EAGAIN) { | |
672 | ret = 0; | |
673 | } | |
674 | break; | |
675 | } | |
676 | } | |
677 | ||
678 | /* If every buffer FD has hung up, we end the read loop here */ | |
679 | if (nb_fd > 0 && num_hup == nb_fd) { | |
680 | DBG("every buffer FD has hung up\n"); | |
681 | send_error(KCONSUMERD_POLL_HUP); | |
682 | continue; | |
683 | } | |
684 | ||
685 | /* Take care of low priority channels. */ | |
686 | if (!high_prio) { | |
687 | for (i = 0; i < nb_fd; i++) { | |
688 | switch(pollfd[i].revents) { | |
689 | case POLLIN: | |
690 | DBG("Normal read on fd %d", pollfd[i].fd); | |
691 | ret = read_subbuffer(&local_kconsumerd_fd[i]); | |
692 | /* it's ok to have an unavailable subbuffer (FIXME : is it ?) */ | |
693 | if (ret == EAGAIN) { | |
694 | ret = 0; | |
695 | } | |
696 | break; | |
697 | } | |
698 | } | |
699 | } | |
700 | } | |
701 | end: | |
702 | if (pollfd != NULL) { | |
703 | free(pollfd); | |
704 | pollfd = NULL; | |
705 | } | |
706 | if (local_kconsumerd_fd != NULL) { | |
707 | free(local_kconsumerd_fd); | |
708 | local_kconsumerd_fd = NULL; | |
709 | } | |
bcd8d9db | 710 | cleanup(); |
d4a1283e JD |
711 | return NULL; |
712 | } | |
713 | ||
714 | /* | |
715 | * usage function on stderr | |
716 | */ | |
717 | static void usage(void) | |
718 | { | |
719 | fprintf(stderr, "Usage: %s OPTIONS\n\nOptions:\n", progname); | |
720 | fprintf(stderr, " -h, --help " | |
721 | "Display this usage.\n"); | |
722 | fprintf(stderr, " -c, --kconsumerd-cmd-sock PATH " | |
723 | "Specify path for the command socket\n"); | |
724 | fprintf(stderr, " -e, --kconsumerd-err-sock PATH " | |
725 | "Specify path for the error socket\n"); | |
726 | fprintf(stderr, " -d, --daemonize " | |
727 | "Start as a daemon.\n"); | |
728 | fprintf(stderr, " -q, --quiet " | |
729 | "No output at all.\n"); | |
730 | fprintf(stderr, " -v, --verbose " | |
731 | "Verbose mode. Activate DBG() macro.\n"); | |
732 | fprintf(stderr, " -V, --version " | |
733 | "Show version number.\n"); | |
734 | } | |
735 | ||
736 | /* | |
737 | * daemon argument parsing | |
738 | */ | |
739 | static void parse_args(int argc, char **argv) | |
740 | { | |
741 | int c; | |
742 | ||
743 | static struct option long_options[] = { | |
744 | { "kconsumerd-cmd-sock", 1, 0, 'c' }, | |
745 | { "kconsumerd-err-sock", 1, 0, 'e' }, | |
746 | { "daemonize", 0, 0, 'd' }, | |
747 | { "help", 0, 0, 'h' }, | |
748 | { "quiet", 0, 0, 'q' }, | |
749 | { "verbose", 0, 0, 'v' }, | |
750 | { "version", 0, 0, 'V' }, | |
751 | { NULL, 0, 0, 0 } | |
752 | }; | |
753 | ||
754 | while (1) { | |
755 | int option_index = 0; | |
756 | c = getopt_long(argc, argv, "dhqvV" "c:e:", long_options, &option_index); | |
757 | if (c == -1) { | |
758 | break; | |
759 | } | |
760 | ||
761 | switch (c) { | |
762 | case 0: | |
763 | fprintf(stderr, "option %s", long_options[option_index].name); | |
764 | if (optarg) { | |
765 | fprintf(stderr, " with arg %s\n", optarg); | |
766 | } | |
767 | break; | |
768 | case 'c': | |
769 | snprintf(command_sock_path, PATH_MAX, "%s", optarg); | |
770 | break; | |
771 | case 'e': | |
772 | snprintf(error_sock_path, PATH_MAX, "%s", optarg); | |
773 | break; | |
774 | case 'd': | |
775 | opt_daemon = 1; | |
776 | break; | |
777 | case 'h': | |
778 | usage(); | |
779 | exit(EXIT_FAILURE); | |
780 | case 'q': | |
781 | opt_quiet = 1; | |
782 | break; | |
783 | case 'v': | |
784 | opt_verbose = 1; | |
785 | break; | |
786 | case 'V': | |
787 | fprintf(stdout, "%s\n", VERSION); | |
788 | exit(EXIT_SUCCESS); | |
789 | default: | |
790 | usage(); | |
791 | exit(EXIT_FAILURE); | |
792 | } | |
793 | } | |
794 | } | |
795 | ||
796 | ||
797 | /* | |
798 | * main | |
799 | */ | |
800 | int main(int argc, char **argv) | |
801 | { | |
802 | int i; | |
803 | int ret = 0; | |
804 | void *status; | |
805 | ||
806 | /* Parse arguments */ | |
807 | progname = argv[0]; | |
808 | parse_args(argc, argv); | |
809 | ||
810 | /* Daemonize */ | |
811 | if (opt_daemon) { | |
812 | ret = daemon(0, 0); | |
813 | if (ret < 0) { | |
814 | perror("daemon"); | |
815 | goto error; | |
816 | } | |
817 | } | |
818 | ||
819 | if (strlen(command_sock_path) == 0) { | |
820 | snprintf(command_sock_path, PATH_MAX, | |
821 | KCONSUMERD_CMD_SOCK_PATH); | |
822 | } | |
823 | if (strlen(error_sock_path) == 0) { | |
824 | snprintf(error_sock_path, PATH_MAX, | |
825 | KCONSUMERD_ERR_SOCK_PATH); | |
826 | } | |
827 | ||
828 | if (set_signal_handler() < 0) { | |
829 | goto error; | |
830 | } | |
831 | ||
832 | /* Connect to the socket created by ltt-sessiond to report errors */ | |
833 | DBG("Connecting to error socket %s", error_sock_path); | |
834 | error_socket = lttcomm_connect_unix_sock(error_sock_path); | |
835 | /* not a fatal error, but all communication with ltt-sessiond will fail */ | |
836 | if (error_socket < 0) { | |
837 | WARN("Cannot connect to error socket, is ltt-sessiond started ?"); | |
838 | } | |
839 | ||
840 | /* Create the thread to manage the receive of fd */ | |
841 | ret = pthread_create(&threads[0], NULL, thread_receive_fds, (void *) NULL); | |
842 | if (ret != 0) { | |
843 | perror("pthread_create"); | |
844 | goto error; | |
845 | } | |
846 | ||
847 | /* Create thread to manage the polling/writing of traces */ | |
848 | ret = pthread_create(&threads[1], NULL, thread_poll_fds, (void *) NULL); | |
849 | if (ret != 0) { | |
850 | perror("pthread_create"); | |
851 | goto error; | |
852 | } | |
853 | ||
854 | for (i = 0; i < 2; i++) { | |
855 | ret = pthread_join(threads[i], &status); | |
856 | if (ret != 0) { | |
857 | perror("pthread_join"); | |
858 | goto error; | |
859 | } | |
860 | } | |
861 | ret = EXIT_SUCCESS; | |
862 | send_error(KCONSUMERD_EXIT_SUCCESS); | |
863 | goto end; | |
864 | ||
865 | error: | |
866 | ret = EXIT_FAILURE; | |
867 | send_error(KCONSUMERD_EXIT_FAILURE); | |
868 | ||
869 | end: | |
870 | cleanup(); | |
871 | ||
872 | return ret; | |
873 | } |