Fix handling of multiple FDs
[lttng-tools.git] / ltt-sessiond / main.c
... / ...
CommitLineData
1/*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version 2
7 * of the License, or (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 */
18
19#define _GNU_SOURCE
20#include <fcntl.h>
21#include <getopt.h>
22#include <grp.h>
23#include <limits.h>
24#include <pthread.h>
25#include <signal.h>
26#include <stdio.h>
27#include <stdlib.h>
28#include <string.h>
29#include <sys/ipc.h>
30#include <sys/shm.h>
31#include <sys/socket.h>
32#include <sys/stat.h>
33#include <sys/types.h>
34#include <unistd.h>
35
36#include <urcu/list.h> /* URCU list library (-lurcu) */
37#include <ust/ustctl.h> /* UST control lib (-lust) */
38#include <lttng/lttng.h>
39
40#include "liblttsessiondcomm.h"
41#include "ltt-sessiond.h"
42#include "lttngerr.h"
43#include "kernel-ctl.h"
44#include "session.h"
45#include "trace.h"
46#include "traceable-app.h"
47
48/*
49 * TODO:
50 * teardown: signal SIGTERM handler -> write into pipe. Threads waits
51 * with epoll on pipe and on other pipes/sockets for commands. Main
52 * simply waits on pthread join.
53 */
54
55/* Const values */
56const char default_home_dir[] = DEFAULT_HOME_DIR;
57const char default_tracing_group[] = DEFAULT_TRACING_GROUP;
58const char default_ust_sock_dir[] = DEFAULT_UST_SOCK_DIR;
59const char default_global_apps_pipe[] = DEFAULT_GLOBAL_APPS_PIPE;
60
61/* Static functions */
62static int check_existing_daemon(void);
63static int ust_connect_app(pid_t pid);
64static int init_daemon_socket(void);
65static int notify_apps(const char* name);
66static int process_client_msg(struct command_ctx *cmd_ctx);
67static int send_unix_sock(int sock, void *buf, size_t len);
68static int set_signal_handler(void);
69static int set_permissions(void);
70static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size);
71static int create_lttng_rundir(void);
72static int set_kconsumerd_sockets(void);
73static void cleanup(void);
74static void sighandler(int sig);
75static void clean_command_ctx(struct command_ctx *cmd_ctx);
76
77static void *thread_manage_clients(void *data);
78static void *thread_manage_apps(void *data);
79static void *thread_manage_kconsumerd(void *data);
80
81/* Variables */
82int opt_verbose;
83int opt_quiet;
84const char *progname;
85const char *opt_tracing_group;
86static int opt_sig_parent;
87static int opt_daemon;
88static int is_root; /* Set to 1 if the daemon is running as root */
89static pid_t ppid;
90
91static char apps_unix_sock_path[PATH_MAX]; /* Global application Unix socket path */
92static char client_unix_sock_path[PATH_MAX]; /* Global client Unix socket path */
93static char kconsumerd_err_unix_sock_path[PATH_MAX]; /* kconsumerd error Unix socket path */
94static char kconsumerd_cmd_unix_sock_path[PATH_MAX]; /* kconsumerd command Unix socket path */
95
96static int client_sock;
97static int apps_sock;
98static int kconsumerd_err_sock;
99static int kernel_tracer_fd;
100
101/*
102 * thread_manage_kconsumerd
103 *
104 * This thread manage the kconsumerd error sent
105 * back to the session daemon.
106 */
107static void *thread_manage_kconsumerd(void *data)
108{
109 int sock, ret;
110
111 DBG("[thread] Manage kconsumerd started");
112
113 ret = lttcomm_listen_unix_sock(kconsumerd_err_sock);
114 if (ret < 0) {
115 goto error;
116 }
117
118 sock = lttcomm_accept_unix_sock(kconsumerd_err_sock);
119 if (sock < 0) {
120 goto error;
121 }
122
123 while (1) {
124 //ret = lttcomm_recv_unix_sock(sock, &lsm, sizeof(lsm));
125 if (ret <= 0) {
126 /* TODO: Consumerd died? */
127 continue;
128 }
129 }
130
131error:
132 return NULL;
133}
134
135/*
136 * thread_manage_apps
137 *
138 * This thread manage the application socket communication
139 */
140static void *thread_manage_apps(void *data)
141{
142 int sock, ret;
143
144 /* TODO: Something more elegant is needed but fine for now */
145 /* FIXME: change all types to either uint8_t, uint32_t, uint64_t
146 * for 32-bit vs 64-bit compat processes. */
147 /* replicate in ust with version number */
148 struct {
149 int reg; /* 1:register, 0:unregister */
150 pid_t pid;
151 uid_t uid;
152 } reg_msg;
153
154 DBG("[thread] Manage apps started");
155
156 ret = lttcomm_listen_unix_sock(apps_sock);
157 if (ret < 0) {
158 goto error;
159 }
160
161 /* Notify all applications to register */
162 notify_apps(default_global_apps_pipe);
163
164 while (1) {
165 DBG("Accepting application registration");
166 /* Blocking call, waiting for transmission */
167 sock = lttcomm_accept_unix_sock(apps_sock);
168 if (sock < 0) {
169 goto error;
170 }
171
172 /* Basic recv here to handle the very simple data
173 * that the libust send to register (reg_msg).
174 */
175 ret = recv(sock, &reg_msg, sizeof(reg_msg), 0);
176 if (ret < 0) {
177 perror("recv");
178 continue;
179 }
180
181 /* Add application to the global traceable list */
182 if (reg_msg.reg == 1) {
183 /* Registering */
184 ret = register_traceable_app(reg_msg.pid, reg_msg.uid);
185 if (ret < 0) {
186 /* register_traceable_app only return an error with
187 * ENOMEM. At this point, we better stop everything.
188 */
189 goto error;
190 }
191 } else {
192 /* Unregistering */
193 unregister_traceable_app(reg_msg.pid);
194 }
195 }
196
197error:
198
199 return NULL;
200}
201
202/*
203 * thread_manage_clients
204 *
205 * This thread manage all clients request using the unix
206 * client socket for communication.
207 */
208static void *thread_manage_clients(void *data)
209{
210 int sock, ret;
211 struct command_ctx *cmd_ctx;
212
213 DBG("[thread] Manage client started");
214
215 ret = lttcomm_listen_unix_sock(client_sock);
216 if (ret < 0) {
217 goto error;
218 }
219
220 /* Notify parent pid that we are ready
221 * to accept command for client side.
222 */
223 if (opt_sig_parent) {
224 kill(ppid, SIGCHLD);
225 }
226
227 while (1) {
228 /* Blocking call, waiting for transmission */
229 DBG("Accepting client command ...");
230 sock = lttcomm_accept_unix_sock(client_sock);
231 if (sock < 0) {
232 goto error;
233 }
234
235 /* Allocate context command to process the client request */
236 cmd_ctx = malloc(sizeof(struct command_ctx));
237
238 /* Allocate data buffer for reception */
239 cmd_ctx->lsm = malloc(sizeof(struct lttcomm_session_msg));
240 cmd_ctx->llm = NULL;
241 cmd_ctx->session = NULL;
242
243 /*
244 * Data is received from the lttng client. The struct
245 * lttcomm_session_msg (lsm) contains the command and data request of
246 * the client.
247 */
248 DBG("Receiving data from client ...");
249 ret = lttcomm_recv_unix_sock(sock, cmd_ctx->lsm, sizeof(struct lttcomm_session_msg));
250 if (ret <= 0) {
251 continue;
252 }
253
254 /*
255 * This function dispatch the work to the kernel or userspace tracer
256 * libs and fill the lttcomm_lttng_msg data structure of all the needed
257 * informations for the client. The command context struct contains
258 * everything this function may needs.
259 */
260 ret = process_client_msg(cmd_ctx);
261 if (ret < 0) {
262 /* TODO: Inform client somehow of the fatal error. At this point,
263 * ret < 0 means that a malloc failed (ENOMEM). */
264 /* Error detected but still accept command */
265 clean_command_ctx(cmd_ctx);
266 continue;
267 }
268
269 DBG("Sending response (size: %d, retcode: %d)",
270 cmd_ctx->lttng_msg_size, cmd_ctx->llm->ret_code);
271 ret = send_unix_sock(sock, cmd_ctx->llm, cmd_ctx->lttng_msg_size);
272 if (ret < 0) {
273 ERR("Failed to send data back to client");
274 }
275
276 clean_command_ctx(cmd_ctx);
277 }
278
279error:
280 return NULL;
281}
282
283/*
284 * send_unix_sock
285 *
286 * Send data on a unix socket using the liblttsessiondcomm API.
287 *
288 * Return lttcomm error code.
289 */
290static int send_unix_sock(int sock, void *buf, size_t len)
291{
292 /* Check valid length */
293 if (len <= 0) {
294 return -1;
295 }
296
297 return lttcomm_send_unix_sock(sock, buf, len);
298}
299
300/*
301 * clean_command_ctx
302 *
303 * Free memory of a command context structure.
304 */
305static void clean_command_ctx(struct command_ctx *cmd_ctx)
306{
307 DBG("Clean command context structure %p", cmd_ctx);
308 if (cmd_ctx) {
309 if (cmd_ctx->llm) {
310 free(cmd_ctx->llm);
311 }
312 if (cmd_ctx->lsm) {
313 free(cmd_ctx->lsm);
314 }
315 free(cmd_ctx);
316 cmd_ctx = NULL;
317 }
318}
319
320/*
321 * ust_connect_app
322 *
323 * Return a socket connected to the libust communication socket
324 * of the application identified by the pid.
325 *
326 * If the pid is not found in the traceable list,
327 * return -1 to indicate error.
328 */
329static int ust_connect_app(pid_t pid)
330{
331 int sock;
332 struct ltt_traceable_app *lta;
333
334 DBG("Connect to application pid %d", pid);
335
336 lta = find_app_by_pid(pid);
337 if (lta == NULL) {
338 /* App not found */
339 DBG("Application pid %d not found", pid);
340 return -1;
341 }
342
343 sock = ustctl_connect_pid(lta->pid);
344 if (sock < 0) {
345 ERR("Fail connecting to the PID %d\n", pid);
346 }
347
348 return sock;
349}
350
351/*
352 * notify_apps
353 *
354 * Notify apps by writing 42 to a named pipe using name.
355 * Every applications waiting for a ltt-sessiond will be notified
356 * and re-register automatically to the session daemon.
357 *
358 * Return open or write error value.
359 */
360static int notify_apps(const char *name)
361{
362 int fd;
363 int ret = -1;
364
365 DBG("Notify the global application pipe");
366
367 /* Try opening the global pipe */
368 fd = open(name, O_WRONLY);
369 if (fd < 0) {
370 goto error;
371 }
372
373 /* Notify by writing on the pipe */
374 ret = write(fd, "42", 2);
375 if (ret < 0) {
376 perror("write");
377 }
378
379error:
380 return ret;
381}
382
383/*
384 * setup_lttng_msg
385 *
386 * Setup the outgoing data buffer for the response (llm) by allocating the
387 * right amount of memory and copying the original information from the lsm
388 * structure.
389 *
390 * Return total size of the buffer pointed by buf.
391 */
392static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size)
393{
394 int ret, buf_size, trace_name_size;
395
396 /*
397 * Check for the trace_name. If defined, it's part of the payload data of
398 * the llm structure.
399 */
400 trace_name_size = strlen(cmd_ctx->lsm->trace_name);
401 buf_size = trace_name_size + size;
402
403 cmd_ctx->llm = malloc(sizeof(struct lttcomm_lttng_msg) + buf_size);
404 if (cmd_ctx->llm == NULL) {
405 perror("malloc");
406 ret = -ENOMEM;
407 goto error;
408 }
409
410 /* Copy common data */
411 cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
412 cmd_ctx->llm->pid = cmd_ctx->lsm->pid;
413 if (!uuid_is_null(cmd_ctx->lsm->session_uuid)) {
414 uuid_copy(cmd_ctx->llm->session_uuid, cmd_ctx->lsm->session_uuid);
415 }
416
417 cmd_ctx->llm->trace_name_offset = trace_name_size;
418 cmd_ctx->llm->data_size = size;
419 cmd_ctx->lttng_msg_size = sizeof(struct lttcomm_lttng_msg) + buf_size;
420
421 /* Copy trace name to the llm structure. Begining of the payload. */
422 memcpy(cmd_ctx->llm->payload, cmd_ctx->lsm->trace_name, trace_name_size);
423
424 return buf_size;
425
426error:
427 return ret;
428}
429
430/*
431 * process_client_msg
432 *
433 * Process the command requested by the lttng client within the command
434 * context structure. This function make sure that the return structure (llm)
435 * is set and ready for transmission before returning.
436 *
437 * Return any error encountered or 0 for success.
438 */
439static int process_client_msg(struct command_ctx *cmd_ctx)
440{
441 int ret;
442
443 DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
444
445 /* Check command that needs a session */
446 switch (cmd_ctx->lsm->cmd_type) {
447 case LTTNG_CREATE_SESSION:
448 case LTTNG_LIST_SESSIONS:
449 case UST_LIST_APPS:
450 break;
451 default:
452 cmd_ctx->session = find_session_by_uuid(cmd_ctx->lsm->session_uuid);
453 if (cmd_ctx->session == NULL) {
454 ret = LTTCOMM_SELECT_SESS;
455 goto error;
456 }
457 break;
458 }
459
460 /* Check command for kernel tracing */
461 switch (cmd_ctx->lsm->cmd_type) {
462 case KERNEL_CREATE_SESSION:
463 case KERNEL_CREATE_CHANNEL:
464 if (kernel_tracer_fd == 0) {
465 ret = LTTCOMM_KERN_NA;
466 goto error;
467 }
468 break;
469 }
470
471 /* Connect to ust apps if available pid */
472 if (cmd_ctx->lsm->pid > 0) {
473 /* Connect to app using ustctl API */
474 cmd_ctx->ust_sock = ust_connect_app(cmd_ctx->lsm->pid);
475 if (cmd_ctx->ust_sock < 0) {
476 ret = LTTCOMM_NO_TRACEABLE;
477 goto error;
478 }
479 }
480
481 /* Process by command type */
482 switch (cmd_ctx->lsm->cmd_type) {
483 case KERNEL_CREATE_SESSION:
484 {
485 ret = setup_lttng_msg(cmd_ctx, 0);
486 if (ret < 0) {
487 goto setup_error;
488 }
489
490 DBG("Creating kernel session");
491
492 ret = kernel_create_session(cmd_ctx, kernel_tracer_fd);
493 if (ret < 0) {
494 ret = LTTCOMM_KERN_SESS_FAIL;
495 goto error;
496 }
497
498 ret = LTTCOMM_OK;
499 break;
500 }
501 case KERNEL_CREATE_CHANNEL:
502 {
503 ret = setup_lttng_msg(cmd_ctx, 0);
504 if (ret < 0) {
505 goto setup_error;
506 }
507
508 DBG("Creating kernel session");
509
510 ret = kernel_create_channel(cmd_ctx);
511 if (ret < 0) {
512 ret = LTTCOMM_KERN_CHAN_FAIL;
513 goto error;
514 }
515
516 ret = LTTCOMM_OK;
517 break;
518 }
519 case KERNEL_ENABLE_EVENT:
520 {
521 /* Setup lttng message with no payload */
522 ret = setup_lttng_msg(cmd_ctx, 0);
523 if (ret < 0) {
524 goto setup_error;
525 }
526
527 DBG("Enabling kernel event %s", cmd_ctx->lsm->u.event.event_name);
528
529 ret = kernel_enable_event(cmd_ctx->session->kernel_session->channel, cmd_ctx->lsm->u.event.event_name);
530 if (ret < 0) {
531 ret = LTTCOMM_KERN_ENABLE_FAIL;
532 goto error;
533 }
534
535 ret = LTTCOMM_OK;
536 break;
537 }
538 case LTTNG_CREATE_SESSION:
539 {
540 /* Setup lttng message with no payload */
541 ret = setup_lttng_msg(cmd_ctx, 0);
542 if (ret < 0) {
543 goto setup_error;
544 }
545
546 ret = create_session(cmd_ctx->lsm->session_name, &cmd_ctx->llm->session_uuid);
547 if (ret < 0) {
548 if (ret == -1) {
549 ret = LTTCOMM_EXIST_SESS;
550 } else {
551 ret = LTTCOMM_FATAL;
552 }
553 goto error;
554 }
555
556 ret = LTTCOMM_OK;
557 break;
558 }
559 case LTTNG_DESTROY_SESSION:
560 {
561 /* Setup lttng message with no payload */
562 ret = setup_lttng_msg(cmd_ctx, 0);
563 if (ret < 0) {
564 goto setup_error;
565 }
566
567 ret = destroy_session(&cmd_ctx->lsm->session_uuid);
568 if (ret < 0) {
569 ret = LTTCOMM_NO_SESS;
570 goto error;
571 }
572
573 ret = LTTCOMM_OK;
574 break;
575 }
576 case LTTNG_LIST_TRACES:
577 {
578 unsigned int trace_count;
579
580 trace_count = get_trace_count_per_session(cmd_ctx->session);
581 if (trace_count == 0) {
582 ret = LTTCOMM_NO_TRACE;
583 goto error;
584 }
585
586 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_trace) * trace_count);
587 if (ret < 0) {
588 goto setup_error;
589 }
590
591 get_traces_per_session(cmd_ctx->session,
592 (struct lttng_trace *)(cmd_ctx->llm->payload));
593
594 ret = LTTCOMM_OK;
595 break;
596 }
597 case UST_CREATE_TRACE:
598 {
599 /* Setup lttng message with no payload */
600 ret = setup_lttng_msg(cmd_ctx, 0);
601 if (ret < 0) {
602 goto setup_error;
603 }
604
605 ret = ust_create_trace(cmd_ctx);
606 if (ret < 0) {
607 goto setup_error;
608 }
609 break;
610 }
611 case UST_LIST_APPS:
612 {
613 unsigned int app_count;
614
615 app_count = get_app_count();
616 DBG("Traceable application count : %d", app_count);
617 if (app_count == 0) {
618 ret = LTTCOMM_NO_APPS;
619 goto error;
620 }
621
622 ret = setup_lttng_msg(cmd_ctx, sizeof(pid_t) * app_count);
623 if (ret < 0) {
624 goto setup_error;
625 }
626
627 get_app_list_pids((pid_t *)(cmd_ctx->llm->payload));
628
629 ret = LTTCOMM_OK;
630 break;
631 }
632 case UST_START_TRACE:
633 {
634 /* Setup lttng message with no payload */
635 ret = setup_lttng_msg(cmd_ctx, 0);
636 if (ret < 0) {
637 goto setup_error;
638 }
639
640 ret = ust_start_trace(cmd_ctx);
641 if (ret < 0) {
642 goto setup_error;
643 }
644 break;
645 }
646 case UST_STOP_TRACE:
647 {
648 /* Setup lttng message with no payload */
649 ret = setup_lttng_msg(cmd_ctx, 0);
650 if (ret < 0) {
651 goto setup_error;
652 }
653
654 ret = ust_stop_trace(cmd_ctx);
655 if (ret < 0) {
656 goto setup_error;
657 }
658 break;
659 }
660 case LTTNG_LIST_SESSIONS:
661 {
662 unsigned int session_count;
663
664 session_count = get_session_count();
665 if (session_count == 0) {
666 ret = LTTCOMM_NO_SESS;
667 goto error;
668 }
669
670 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_session) * session_count);
671 if (ret < 0) {
672 goto setup_error;
673 }
674
675 get_lttng_session((struct lttng_session *)(cmd_ctx->llm->payload));
676
677 ret = LTTCOMM_OK;
678 break;
679 }
680 default:
681 /* Undefined command */
682 ret = setup_lttng_msg(cmd_ctx, 0);
683 if (ret < 0) {
684 goto setup_error;
685 }
686
687 ret = LTTCOMM_UND;
688 break;
689 }
690
691 /* Set return code */
692 cmd_ctx->llm->ret_code = ret;
693
694 return ret;
695
696error:
697 if (cmd_ctx->llm == NULL) {
698 DBG("Missing llm structure. Allocating one.");
699 if (setup_lttng_msg(cmd_ctx, 0) < 0) {
700 goto setup_error;
701 }
702 }
703 /* Notify client of error */
704 cmd_ctx->llm->ret_code = ret;
705
706setup_error:
707 return ret;
708}
709
710/*
711 * usage function on stderr
712 */
713static void usage(void)
714{
715 fprintf(stderr, "Usage: %s OPTIONS\n\nOptions:\n", progname);
716 fprintf(stderr, " -h, --help Display this usage.\n");
717 fprintf(stderr, " -c, --client-sock PATH Specify path for the client unix socket\n");
718 fprintf(stderr, " -a, --apps-sock PATH Specify path for apps unix socket\n");
719 fprintf(stderr, " --kconsumerd-err-sock PATH Specify path for the kernel consumer error socket\n");
720 fprintf(stderr, " --kconsumerd-cmd-sock PATH Specify path for the kernel consumer command socket\n");
721 fprintf(stderr, " -d, --daemonize Start as a daemon.\n");
722 fprintf(stderr, " -g, --group NAME Specify the tracing group name. (default: tracing)\n");
723 fprintf(stderr, " -V, --version Show version number.\n");
724 fprintf(stderr, " -S, --sig-parent Send SIGCHLD to parent pid to notify readiness.\n");
725 fprintf(stderr, " -q, --quiet No output at all.\n");
726 fprintf(stderr, " -v, --verbose Verbose mode. Activate DBG() macro.\n");
727}
728
729/*
730 * daemon argument parsing
731 */
732static int parse_args(int argc, char **argv)
733{
734 int c;
735
736 static struct option long_options[] = {
737 { "client-sock", 1, 0, 'c' },
738 { "apps-sock", 1, 0, 'a' },
739 { "kconsumerd-cmd-sock", 1, 0, 0 },
740 { "kconsumerd-err-sock", 1, 0, 0 },
741 { "daemonize", 0, 0, 'd' },
742 { "sig-parent", 0, 0, 'S' },
743 { "help", 0, 0, 'h' },
744 { "group", 1, 0, 'g' },
745 { "version", 0, 0, 'V' },
746 { "quiet", 0, 0, 'q' },
747 { "verbose", 0, 0, 'v' },
748 { NULL, 0, 0, 0 }
749 };
750
751 while (1) {
752 int option_index = 0;
753 c = getopt_long(argc, argv, "dhqvVS" "a:c:g:s:E:C:", long_options, &option_index);
754 if (c == -1) {
755 break;
756 }
757
758 switch (c) {
759 case 0:
760 fprintf(stderr, "option %s", long_options[option_index].name);
761 if (optarg) {
762 fprintf(stderr, " with arg %s\n", optarg);
763 }
764 break;
765 case 'c':
766 snprintf(client_unix_sock_path, PATH_MAX, "%s", optarg);
767 break;
768 case 'a':
769 snprintf(apps_unix_sock_path, PATH_MAX, "%s", optarg);
770 break;
771 case 'd':
772 opt_daemon = 1;
773 break;
774 case 'g':
775 opt_tracing_group = strdup(optarg);
776 break;
777 case 'h':
778 usage();
779 exit(EXIT_FAILURE);
780 case 'V':
781 fprintf(stdout, "%s\n", VERSION);
782 exit(EXIT_SUCCESS);
783 case 'S':
784 opt_sig_parent = 1;
785 break;
786 case 'E':
787 snprintf(kconsumerd_err_unix_sock_path, PATH_MAX, "%s", optarg);
788 break;
789 case 'C':
790 snprintf(kconsumerd_cmd_unix_sock_path, PATH_MAX, "%s", optarg);
791 break;
792 case 'q':
793 opt_quiet = 1;
794 break;
795 case 'v':
796 opt_verbose = 1;
797 break;
798 default:
799 /* Unknown option or other error.
800 * Error is printed by getopt, just return */
801 return -1;
802 }
803 }
804
805 return 0;
806}
807
808/*
809 * init_daemon_socket
810 *
811 * Creates the two needed socket by the daemon.
812 * apps_sock - The communication socket for all UST apps.
813 * client_sock - The communication of the cli tool (lttng).
814 */
815static int init_daemon_socket()
816{
817 int ret = 0;
818 mode_t old_umask;
819
820 old_umask = umask(0);
821
822 /* Create client tool unix socket */
823 client_sock = lttcomm_create_unix_sock(client_unix_sock_path);
824 if (client_sock < 0) {
825 ERR("Create unix sock failed: %s", client_unix_sock_path);
826 ret = -1;
827 goto end;
828 }
829
830 /* File permission MUST be 660 */
831 ret = chmod(client_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
832 if (ret < 0) {
833 ERR("Set file permissions failed: %s", client_unix_sock_path);
834 perror("chmod");
835 goto end;
836 }
837
838 /* Create the application unix socket */
839 apps_sock = lttcomm_create_unix_sock(apps_unix_sock_path);
840 if (apps_sock < 0) {
841 ERR("Create unix sock failed: %s", apps_unix_sock_path);
842 ret = -1;
843 goto end;
844 }
845
846 /* File permission MUST be 666 */
847 ret = chmod(apps_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
848 if (ret < 0) {
849 ERR("Set file permissions failed: %s", apps_unix_sock_path);
850 perror("chmod");
851 goto end;
852 }
853
854end:
855 umask(old_umask);
856 return ret;
857}
858
859/*
860 * check_existing_daemon
861 *
862 * Check if the global socket is available.
863 * If yes, error is returned.
864 */
865static int check_existing_daemon()
866{
867 int ret;
868
869 ret = access(client_unix_sock_path, F_OK);
870 if (ret == 0) {
871 ret = access(apps_unix_sock_path, F_OK);
872 }
873
874 return ret;
875}
876
877/*
878 * get_home_dir
879 *
880 * Return pointer to home directory path using
881 * the env variable HOME.
882 *
883 * Default : /tmp
884 */
885static const char *get_home_dir(void)
886{
887 const char *home_path;
888
889 if ((home_path = (const char *) getenv("HOME")) == NULL) {
890 home_path = default_home_dir;
891 }
892
893 return home_path;
894}
895
896/*
897 * set_permissions
898 *
899 * Set the tracing group gid onto the client socket.
900 *
901 * Race window between mkdir and chown is OK because we are going from
902 * less permissive (root.root) to more permissive (root.tracing).
903 */
904static int set_permissions(void)
905{
906 int ret;
907 struct group *grp;
908
909 /* Decide which group name to use */
910 (opt_tracing_group != NULL) ?
911 (grp = getgrnam(opt_tracing_group)) :
912 (grp = getgrnam(default_tracing_group));
913
914 if (grp == NULL) {
915 ERR("Missing tracing group. Aborting execution.\n");
916 ret = -1;
917 goto end;
918 }
919
920 /* Set lttng run dir */
921 ret = chown(LTTNG_RUNDIR, 0, grp->gr_gid);
922 if (ret < 0) {
923 ERR("Unable to set group on " LTTNG_RUNDIR);
924 perror("chown");
925 }
926
927 /* lttng client socket path */
928 ret = chown(client_unix_sock_path, 0, grp->gr_gid);
929 if (ret < 0) {
930 ERR("Unable to set group on %s", client_unix_sock_path);
931 perror("chown");
932 }
933
934 /* kconsumerd error socket path */
935 ret = chown(kconsumerd_err_unix_sock_path, 0, grp->gr_gid);
936 if (ret < 0) {
937 ERR("Unable to set group on %s", kconsumerd_err_unix_sock_path);
938 perror("chown");
939 }
940
941 DBG("All permissions are set");
942
943end:
944 return ret;
945}
946
947/*
948 * create_lttng_rundir
949 *
950 * Create the lttng run directory needed for all
951 * global sockets and pipe.
952 */
953static int create_lttng_rundir(void)
954{
955 int ret;
956
957 ret = mkdir(LTTNG_RUNDIR, S_IRWXU | S_IRWXG );
958 if (ret < 0) {
959 ERR("Unable to create " LTTNG_RUNDIR);
960 goto error;
961 }
962
963error:
964 return ret;
965}
966
967/*
968 * init_kernel_tracer
969 *
970 * Setup necessary data for kernel tracer action.
971 */
972static void init_kernel_tracer(void)
973{
974 /* Set the global kernel tracer fd */
975 kernel_tracer_fd = open(DEFAULT_KERNEL_TRACER_PATH, O_RDWR);
976 if (kernel_tracer_fd < 0) {
977 WARN("No kernel tracer available");
978 kernel_tracer_fd = 0;
979 }
980}
981
982/*
983 * set_kconsumerd_sockets
984 *
985 * Setup sockets and directory needed by the kconsumerd
986 * communication with the session daemon.
987 */
988static int set_kconsumerd_sockets(void)
989{
990 int ret;
991
992 if (strlen(kconsumerd_err_unix_sock_path) == 0) {
993 snprintf(kconsumerd_err_unix_sock_path, PATH_MAX, KCONSUMERD_ERR_SOCK_PATH);
994 }
995
996 if (strlen(kconsumerd_cmd_unix_sock_path) == 0) {
997 snprintf(kconsumerd_cmd_unix_sock_path, PATH_MAX, KCONSUMERD_CMD_SOCK_PATH);
998 }
999
1000 ret = mkdir(KCONSUMERD_PATH, S_IRWXU | S_IRWXG);
1001 if (ret < 0) {
1002 ERR("Failed to create " KCONSUMERD_PATH);
1003 goto error;
1004 }
1005
1006 /* Create the kconsumerd error unix socket */
1007 kconsumerd_err_sock = lttcomm_create_unix_sock(kconsumerd_err_unix_sock_path);
1008 if (kconsumerd_err_sock < 0) {
1009 ERR("Create unix sock failed: %s", kconsumerd_err_unix_sock_path);
1010 ret = -1;
1011 goto error;
1012 }
1013
1014 /* File permission MUST be 660 */
1015 ret = chmod(kconsumerd_err_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
1016 if (ret < 0) {
1017 ERR("Set file permissions failed: %s", kconsumerd_err_unix_sock_path);
1018 perror("chmod");
1019 goto error;
1020 }
1021
1022error:
1023 return ret;
1024}
1025
1026/*
1027 * set_signal_handler
1028 *
1029 * Setup signal handler for :
1030 * SIGINT, SIGTERM, SIGPIPE
1031 */
1032static int set_signal_handler(void)
1033{
1034 int ret = 0;
1035 struct sigaction sa;
1036 sigset_t sigset;
1037
1038 if ((ret = sigemptyset(&sigset)) < 0) {
1039 perror("sigemptyset");
1040 return ret;
1041 }
1042
1043 sa.sa_handler = sighandler;
1044 sa.sa_mask = sigset;
1045 sa.sa_flags = 0;
1046 if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
1047 perror("sigaction");
1048 return ret;
1049 }
1050
1051 if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
1052 perror("sigaction");
1053 return ret;
1054 }
1055
1056 if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
1057 perror("sigaction");
1058 return ret;
1059 }
1060
1061 DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT");
1062
1063 return ret;
1064}
1065
1066/**
1067 * sighandler
1068 *
1069 * Signal handler for the daemon
1070 */
1071static void sighandler(int sig)
1072{
1073 switch (sig) {
1074 case SIGPIPE:
1075 DBG("SIGPIPE catched");
1076 return;
1077 case SIGINT:
1078 DBG("SIGINT catched");
1079 cleanup();
1080 break;
1081 case SIGTERM:
1082 DBG("SIGTERM catched");
1083 cleanup();
1084 break;
1085 default:
1086 break;
1087 }
1088
1089 exit(EXIT_SUCCESS);
1090}
1091
1092/*
1093 * cleanup
1094 *
1095 * Cleanup the daemon on exit
1096 */
1097static void cleanup()
1098{
1099 int ret;
1100 char *cmd;
1101
1102 DBG("Cleaning up");
1103
1104 /* <fun> */
1105 MSG("\n%c[%d;%dm*** assert failed *** ==> %c[%dm", 27,1,31,27,0);
1106 MSG("%c[%d;%dmMatthew, BEET driven development works!%c[%dm",27,1,33,27,0);
1107 /* </fun> */
1108
1109 unlink(client_unix_sock_path);
1110 unlink(apps_unix_sock_path);
1111 unlink(kconsumerd_err_unix_sock_path);
1112
1113 ret = asprintf(&cmd, "rm -rf " LTTNG_RUNDIR);
1114 if (ret < 0) {
1115 ERR("asprintf failed. Something is really wrong!");
1116 }
1117
1118 /* Remove lttng run directory */
1119 ret = system(cmd);
1120 if (ret < 0) {
1121 ERR("Unable to clean " LTTNG_RUNDIR);
1122 }
1123}
1124
1125/*
1126 * main
1127 */
1128int main(int argc, char **argv)
1129{
1130 int i;
1131 int ret = 0;
1132 void *status;
1133 pthread_t threads[2];
1134
1135 /* Parse arguments */
1136 progname = argv[0];
1137 if ((ret = parse_args(argc, argv) < 0)) {
1138 goto error;
1139 }
1140
1141 /* Daemonize */
1142 if (opt_daemon) {
1143 ret = daemon(0, 0);
1144 if (ret < 0) {
1145 perror("daemon");
1146 goto error;
1147 }
1148 }
1149
1150 /* Check if daemon is UID = 0 */
1151 is_root = !getuid();
1152
1153 /* Set all sockets path */
1154 if (is_root) {
1155 ret = create_lttng_rundir();
1156 if (ret < 0) {
1157 goto error;
1158 }
1159
1160 if (strlen(apps_unix_sock_path) == 0) {
1161 snprintf(apps_unix_sock_path, PATH_MAX,
1162 DEFAULT_GLOBAL_APPS_UNIX_SOCK);
1163 }
1164
1165 if (strlen(client_unix_sock_path) == 0) {
1166 snprintf(client_unix_sock_path, PATH_MAX,
1167 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK);
1168 }
1169
1170 ret = set_kconsumerd_sockets();
1171 if (ret < 0) {
1172 goto error;
1173 }
1174
1175 /* Setup kernel tracer */
1176 init_kernel_tracer();
1177 } else {
1178 if (strlen(apps_unix_sock_path) == 0) {
1179 snprintf(apps_unix_sock_path, PATH_MAX,
1180 DEFAULT_HOME_APPS_UNIX_SOCK, get_home_dir());
1181 }
1182
1183 /* Set the cli tool unix socket path */
1184 if (strlen(client_unix_sock_path) == 0) {
1185 snprintf(client_unix_sock_path, PATH_MAX,
1186 DEFAULT_HOME_CLIENT_UNIX_SOCK, get_home_dir());
1187 }
1188 }
1189
1190 DBG("Client socket path %s", client_unix_sock_path);
1191 DBG("Application socket path %s", apps_unix_sock_path);
1192
1193 /* See if daemon already exist. If any of the two
1194 * socket needed by the daemon are present, this test fails
1195 */
1196 if ((ret = check_existing_daemon()) == 0) {
1197 ERR("Already running daemon.\n");
1198 /* We do not goto error because we must not
1199 * cleanup() because a daemon is already running.
1200 */
1201 exit(EXIT_FAILURE);
1202 }
1203
1204 if (set_signal_handler() < 0) {
1205 goto error;
1206 }
1207
1208 /* Setup the needed unix socket */
1209 if (init_daemon_socket() < 0) {
1210 goto error;
1211 }
1212
1213 /* Set credentials to socket */
1214 if (is_root && (set_permissions() < 0)) {
1215 goto error;
1216 }
1217
1218 /* Get parent pid if -S, --sig-parent is specified. */
1219 if (opt_sig_parent) {
1220 ppid = getppid();
1221 }
1222
1223 while (1) {
1224 /* Create thread to manage the client socket */
1225 ret = pthread_create(&threads[0], NULL, thread_manage_clients, (void *) NULL);
1226 if (ret != 0) {
1227 perror("pthread_create");
1228 goto error;
1229 }
1230
1231 /* Create thread to manage application socket */
1232 ret = pthread_create(&threads[1], NULL, thread_manage_apps, (void *) NULL);
1233 if (ret != 0) {
1234 perror("pthread_create");
1235 goto error;
1236 }
1237
1238 for (i = 0; i < 2; i++) {
1239 ret = pthread_join(threads[i], &status);
1240 if (ret != 0) {
1241 perror("pthread_join");
1242 goto error;
1243 }
1244 }
1245 }
1246
1247 cleanup();
1248 exit(EXIT_SUCCESS);
1249
1250error:
1251 cleanup();
1252 exit(EXIT_FAILURE);
1253}
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