2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
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; only version 2
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.
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.
26 #include <semaphore.h>
32 #include <sys/mount.h>
34 #include <sys/socket.h>
36 #include <sys/types.h>
38 #include <sys/resource.h>
41 #include <urcu/list.h> /* URCU list library (-lurcu) */
42 #include <lttng/lttng.h>
44 #include "liblttsessiondcomm.h"
45 #include "ltt-sessiond.h"
47 #include "kernel-ctl.h"
50 #include "traceable-app.h"
51 #include "lttng-kconsumerd.h"
56 * teardown: signal SIGTERM handler -> write into pipe. Threads waits
57 * with epoll on pipe and on other pipes/sockets for commands. Main
58 * simply waits on pthread join.
62 const char default_home_dir
[] = DEFAULT_HOME_DIR
;
63 const char default_tracing_group
[] = LTTNG_DEFAULT_TRACING_GROUP
;
64 const char default_ust_sock_dir
[] = DEFAULT_UST_SOCK_DIR
;
65 const char default_global_apps_pipe
[] = DEFAULT_GLOBAL_APPS_PIPE
;
68 int opt_verbose
; /* Not static for lttngerr.h */
69 int opt_quiet
; /* Not static for lttngerr.h */
71 const char *opt_tracing_group
;
72 static int opt_sig_parent
;
73 static int opt_daemon
;
74 static int is_root
; /* Set to 1 if the daemon is running as root */
75 static pid_t ppid
; /* Parent PID for --sig-parent option */
76 static pid_t kconsumerd_pid
;
77 static struct pollfd
*kernel_pollfd
;
79 static char apps_unix_sock_path
[PATH_MAX
]; /* Global application Unix socket path */
80 static char client_unix_sock_path
[PATH_MAX
]; /* Global client Unix socket path */
81 static char kconsumerd_err_unix_sock_path
[PATH_MAX
]; /* kconsumerd error Unix socket path */
82 static char kconsumerd_cmd_unix_sock_path
[PATH_MAX
]; /* kconsumerd command Unix socket path */
85 static int client_sock
;
87 static int kconsumerd_err_sock
;
88 static int kconsumerd_cmd_sock
;
89 static int kernel_tracer_fd
;
90 static int kernel_poll_pipe
[2];
93 * Quit pipe for all threads. This permits a single cancellation point
94 * for all threads when receiving an event on the pipe.
96 static int thread_quit_pipe
[2];
98 /* Pthread, Mutexes and Semaphores */
99 static pthread_t kconsumerd_thread
;
100 static pthread_t apps_thread
;
101 static pthread_t client_thread
;
102 static pthread_t kernel_thread
;
103 static sem_t kconsumerd_sem
;
105 static pthread_mutex_t kconsumerd_pid_mutex
; /* Mutex to control kconsumerd pid assignation */
108 * Pointer initialized before thread creation.
110 * This points to the tracing session list containing the session count and a
111 * mutex lock. The lock MUST be taken if you iterate over the list. The lock
112 * MUST NOT be taken if you call a public function in session.c.
114 * The lock is nested inside the structure: session_list_ptr->lock.
116 static struct ltt_session_list
*session_list_ptr
;
121 * Return -1 on error or 0 if all pipes are created.
123 static int init_thread_quit_pipe(void)
127 ret
= pipe2(thread_quit_pipe
, O_CLOEXEC
);
129 perror("thread quit pipe");
138 * teardown_kernel_session
140 * Complete teardown of a kernel session. This free all data structure related
141 * to a kernel session and update counter.
143 static void teardown_kernel_session(struct ltt_session
*session
)
145 if (session
->kernel_session
!= NULL
) {
146 DBG("Tearing down kernel session");
147 trace_destroy_kernel_session(session
->kernel_session
);
148 /* Extra precaution */
149 session
->kernel_session
= NULL
;
156 static void cleanup()
160 struct ltt_session
*sess
;
165 MSG("\n%c[%d;%dm*** assert failed *** ==> %c[%dm%c[%d;%dm"
166 "Matthew, BEET driven development works!%c[%dm",
167 27, 1, 31, 27, 0, 27, 1, 33, 27, 0);
170 /* Stopping all threads */
171 DBG("Terminating all threads");
172 close(thread_quit_pipe
[0]);
173 close(thread_quit_pipe
[1]);
175 DBG("Removing %s directory", LTTNG_RUNDIR
);
176 ret
= asprintf(&cmd
, "rm -rf " LTTNG_RUNDIR
);
178 ERR("asprintf failed. Something is really wrong!");
181 /* Remove lttng run directory */
184 ERR("Unable to clean " LTTNG_RUNDIR
);
187 DBG("Cleaning up all session");
189 /* Destroy session list mutex */
190 if (session_list_ptr
!= NULL
) {
191 pthread_mutex_destroy(&session_list_ptr
->lock
);
193 /* Cleanup ALL session */
194 cds_list_for_each_entry(sess
, &session_list_ptr
->head
, list
) {
195 teardown_kernel_session(sess
);
196 // TODO complete session cleanup (including UST)
200 pthread_mutex_destroy(&kconsumerd_pid_mutex
);
202 DBG("Closing kernel fd");
203 close(kernel_tracer_fd
);
209 * Send data on a unix socket using the liblttsessiondcomm API.
211 * Return lttcomm error code.
213 static int send_unix_sock(int sock
, void *buf
, size_t len
)
215 /* Check valid length */
220 return lttcomm_send_unix_sock(sock
, buf
, len
);
226 * Free memory of a command context structure.
228 static void clean_command_ctx(struct command_ctx
**cmd_ctx
)
230 DBG("Clean command context structure");
232 if ((*cmd_ctx
)->llm
) {
233 free((*cmd_ctx
)->llm
);
235 if ((*cmd_ctx
)->lsm
) {
236 free((*cmd_ctx
)->lsm
);
244 * send_kconsumerd_channel_fds
246 * Send all stream fds of kernel channel to the consumer.
248 static int send_kconsumerd_channel_fds(int sock
, struct ltt_kernel_channel
*channel
)
252 struct ltt_kernel_stream
*stream
;
253 struct lttcomm_kconsumerd_header lkh
;
254 struct lttcomm_kconsumerd_msg lkm
;
256 DBG("Sending fds of channel %s to kernel consumer", channel
->channel
->name
);
258 nb_fd
= channel
->stream_count
;
261 lkh
.payload_size
= nb_fd
* sizeof(struct lttcomm_kconsumerd_msg
);
262 lkh
.cmd_type
= ADD_STREAM
;
264 DBG("Sending kconsumerd header");
266 ret
= lttcomm_send_unix_sock(sock
, &lkh
, sizeof(struct lttcomm_kconsumerd_header
));
268 perror("send kconsumerd header");
272 cds_list_for_each_entry(stream
, &channel
->stream_list
.head
, list
) {
273 if (stream
->fd
!= 0) {
275 lkm
.state
= stream
->state
;
276 lkm
.max_sb_size
= channel
->channel
->attr
.subbuf_size
;
277 strncpy(lkm
.path_name
, stream
->pathname
, PATH_MAX
);
279 DBG("Sending fd %d to kconsumerd", lkm
.fd
);
281 ret
= lttcomm_send_fds_unix_sock(sock
, &lkm
, &lkm
.fd
, 1, sizeof(lkm
));
283 perror("send kconsumerd fd");
289 DBG("Kconsumerd channel fds sent");
298 * send_kconsumerd_fds
300 * Send all stream fds of the kernel session to the consumer.
302 static int send_kconsumerd_fds(int sock
, struct ltt_kernel_session
*session
)
305 struct ltt_kernel_channel
*chan
;
306 struct lttcomm_kconsumerd_header lkh
;
307 struct lttcomm_kconsumerd_msg lkm
;
310 lkh
.payload_size
= sizeof(struct lttcomm_kconsumerd_msg
);
311 lkh
.cmd_type
= ADD_STREAM
;
313 DBG("Sending kconsumerd header for metadata");
315 ret
= lttcomm_send_unix_sock(sock
, &lkh
, sizeof(struct lttcomm_kconsumerd_header
));
317 perror("send kconsumerd header");
321 DBG("Sending metadata stream fd");
323 if (session
->metadata_stream_fd
!= 0) {
324 /* Send metadata stream fd first */
325 lkm
.fd
= session
->metadata_stream_fd
;
326 lkm
.state
= ACTIVE_FD
;
327 lkm
.max_sb_size
= session
->metadata
->conf
->attr
.subbuf_size
;
328 strncpy(lkm
.path_name
, session
->metadata
->pathname
, PATH_MAX
);
330 ret
= lttcomm_send_fds_unix_sock(sock
, &lkm
, &lkm
.fd
, 1, sizeof(lkm
));
332 perror("send kconsumerd fd");
337 cds_list_for_each_entry(chan
, &session
->channel_list
.head
, list
) {
338 ret
= send_kconsumerd_channel_fds(sock
, chan
);
344 DBG("Kconsumerd fds (metadata and channel streams) sent");
356 * Return a socket connected to the libust communication socket
357 * of the application identified by the pid.
359 * If the pid is not found in the traceable list,
360 * return -1 to indicate error.
362 static int ust_connect_app(pid_t pid
)
365 struct ltt_traceable_app
*lta
;
367 DBG("Connect to application pid %d", pid
);
369 lta
= find_app_by_pid(pid
);
372 DBG("Application pid %d not found", pid
);
376 sock
= ustctl_connect_pid(lta
->pid
);
378 ERR("Fail connecting to the PID %d", pid
);
383 #endif /* DISABLED */
388 * Notify apps by writing 42 to a named pipe using name.
389 * Every applications waiting for a ltt-sessiond will be notified
390 * and re-register automatically to the session daemon.
392 * Return open or write error value.
394 static int notify_apps(const char *name
)
399 DBG("Notify the global application pipe");
401 /* Try opening the global pipe */
402 fd
= open(name
, O_WRONLY
);
407 /* Notify by writing on the pipe */
408 ret
= write(fd
, "42", 2);
420 * Setup the outgoing data buffer for the response (llm) by allocating the
421 * right amount of memory and copying the original information from the lsm
424 * Return total size of the buffer pointed by buf.
426 static int setup_lttng_msg(struct command_ctx
*cmd_ctx
, size_t size
)
432 cmd_ctx
->llm
= malloc(sizeof(struct lttcomm_lttng_msg
) + buf_size
);
433 if (cmd_ctx
->llm
== NULL
) {
439 /* Copy common data */
440 cmd_ctx
->llm
->cmd_type
= cmd_ctx
->lsm
->cmd_type
;
441 cmd_ctx
->llm
->pid
= cmd_ctx
->lsm
->pid
;
443 cmd_ctx
->llm
->data_size
= size
;
444 cmd_ctx
->lttng_msg_size
= sizeof(struct lttcomm_lttng_msg
) + buf_size
;
453 * update_kernel_pollfd
455 * Update the kernel pollfd set of all channel fd available over
456 * all tracing session. Add the wakeup pipe at the end of the set.
458 static int update_kernel_pollfd(void)
462 * The wakup pipe and the quit pipe are needed so the number of fds starts
463 * at 2 for those pipes.
465 unsigned int nb_fd
= 2;
466 struct ltt_session
*session
;
467 struct ltt_kernel_channel
*channel
;
469 DBG("Updating kernel_pollfd");
471 /* Get the number of channel of all kernel session */
473 cds_list_for_each_entry(session
, &session_list_ptr
->head
, list
) {
474 lock_session(session
);
475 if (session
->kernel_session
== NULL
) {
476 unlock_session(session
);
479 nb_fd
+= session
->kernel_session
->channel_count
;
480 unlock_session(session
);
483 DBG("Resizing kernel_pollfd to size %d", nb_fd
);
485 kernel_pollfd
= realloc(kernel_pollfd
, nb_fd
* sizeof(struct pollfd
));
486 if (kernel_pollfd
== NULL
) {
487 perror("malloc kernel_pollfd");
491 cds_list_for_each_entry(session
, &session_list_ptr
->head
, list
) {
492 lock_session(session
);
493 if (session
->kernel_session
== NULL
) {
494 unlock_session(session
);
498 ERR("To much channel for kernel_pollfd size");
499 unlock_session(session
);
502 cds_list_for_each_entry(channel
, &session
->kernel_session
->channel_list
.head
, list
) {
503 kernel_pollfd
[i
].fd
= channel
->fd
;
504 kernel_pollfd
[i
].events
= POLLIN
| POLLRDNORM
;
507 unlock_session(session
);
509 unlock_session_list();
511 /* Adding wake up pipe */
512 kernel_pollfd
[nb_fd
- 2].fd
= kernel_poll_pipe
[0];
513 kernel_pollfd
[nb_fd
- 2].events
= POLLIN
;
515 /* Adding the quit pipe */
516 kernel_pollfd
[nb_fd
- 1].fd
= thread_quit_pipe
[0];
521 unlock_session_list();
526 * update_kernel_stream
528 * Find the channel fd from 'fd' over all tracing session. When found, check
529 * for new channel stream and send those stream fds to the kernel consumer.
531 * Useful for CPU hotplug feature.
533 static int update_kernel_stream(int fd
)
536 struct ltt_session
*session
;
537 struct ltt_kernel_channel
*channel
;
539 DBG("Updating kernel streams for channel fd %d", fd
);
542 cds_list_for_each_entry(session
, &session_list_ptr
->head
, list
) {
543 lock_session(session
);
544 if (session
->kernel_session
== NULL
) {
545 unlock_session(session
);
548 cds_list_for_each_entry(channel
, &session
->kernel_session
->channel_list
.head
, list
) {
549 if (channel
->fd
== fd
) {
550 DBG("Channel found, updating kernel streams");
551 ret
= kernel_open_channel_stream(channel
);
556 * Have we already sent fds to the consumer? If yes, it means that
557 * tracing is started so it is safe to send our updated stream fds.
559 if (session
->kernel_session
->kconsumer_fds_sent
== 1) {
560 ret
= send_kconsumerd_channel_fds(kconsumerd_cmd_sock
, channel
);
568 unlock_session(session
);
572 unlock_session_list();
574 unlock_session(session
);
580 * thread_manage_kernel
582 * This thread manage event coming from the kernel.
584 * Features supported in this thread:
587 static void *thread_manage_kernel(void *data
)
589 int ret
, i
, nb_fd
= 0;
591 int update_poll_flag
= 1;
593 DBG("Thread manage kernel started");
596 if (update_poll_flag
== 1) {
597 nb_fd
= update_kernel_pollfd();
601 update_poll_flag
= 0;
604 DBG("Polling on %d fds", nb_fd
);
606 /* Poll infinite value of time */
607 ret
= poll(kernel_pollfd
, nb_fd
, -1);
609 perror("poll kernel thread");
611 } else if (ret
== 0) {
612 /* Should not happen since timeout is infinite */
616 /* Thread quit pipe has been closed. Killing thread. */
617 if (kernel_pollfd
[nb_fd
- 1].revents
== POLLNVAL
) {
621 DBG("Kernel poll event triggered");
624 * Check if the wake up pipe was triggered. If so, the kernel_pollfd
627 switch (kernel_pollfd
[nb_fd
- 2].revents
) {
629 ret
= read(kernel_poll_pipe
[0], &tmp
, 1);
630 update_poll_flag
= 1;
638 for (i
= 0; i
< nb_fd
; i
++) {
639 switch (kernel_pollfd
[i
].revents
) {
641 * New CPU detected by the kernel. Adding kernel stream to kernel
642 * session and updating the kernel consumer
644 case POLLIN
| POLLRDNORM
:
645 ret
= update_kernel_stream(kernel_pollfd
[i
].fd
);
655 DBG("Kernel thread dying");
660 close(kernel_poll_pipe
[0]);
661 close(kernel_poll_pipe
[1]);
666 * thread_manage_kconsumerd
668 * This thread manage the kconsumerd error sent
669 * back to the session daemon.
671 static void *thread_manage_kconsumerd(void *data
)
674 enum lttcomm_return_code code
;
675 struct pollfd pollfd
[2];
677 DBG("[thread] Manage kconsumerd started");
679 ret
= lttcomm_listen_unix_sock(kconsumerd_err_sock
);
684 /* First fd is always the quit pipe */
685 pollfd
[0].fd
= thread_quit_pipe
[0];
688 pollfd
[1].fd
= kconsumerd_err_sock
;
689 pollfd
[1].events
= POLLIN
;
691 /* Inifinite blocking call, waiting for transmission */
692 ret
= poll(pollfd
, 2, -1);
694 perror("poll kconsumerd thread");
698 /* Thread quit pipe has been closed. Killing thread. */
699 if (pollfd
[0].revents
== POLLNVAL
) {
701 } else if (pollfd
[1].revents
== POLLERR
) {
702 ERR("Kconsumerd err socket poll error");
706 sock
= lttcomm_accept_unix_sock(kconsumerd_err_sock
);
711 /* Getting status code from kconsumerd */
712 ret
= lttcomm_recv_unix_sock(sock
, &code
, sizeof(enum lttcomm_return_code
));
717 if (code
== KCONSUMERD_COMMAND_SOCK_READY
) {
718 kconsumerd_cmd_sock
= lttcomm_connect_unix_sock(kconsumerd_cmd_unix_sock_path
);
719 if (kconsumerd_cmd_sock
< 0) {
720 sem_post(&kconsumerd_sem
);
721 perror("kconsumerd connect");
724 /* Signal condition to tell that the kconsumerd is ready */
725 sem_post(&kconsumerd_sem
);
726 DBG("Kconsumerd command socket ready");
728 DBG("Kconsumerd error when waiting for SOCK_READY : %s",
729 lttcomm_get_readable_code(-code
));
733 /* Wait for any kconsumerd error */
734 ret
= lttcomm_recv_unix_sock(sock
, &code
, sizeof(enum lttcomm_return_code
));
736 ERR("Kconsumerd closed the command socket");
740 ERR("Kconsumerd return code : %s", lttcomm_get_readable_code(-code
));
743 DBG("Kconsumerd thread dying");
744 if (kconsumerd_err_sock
) {
745 close(kconsumerd_err_sock
);
747 if (kconsumerd_cmd_sock
) {
748 close(kconsumerd_cmd_sock
);
754 unlink(kconsumerd_err_unix_sock_path
);
755 unlink(kconsumerd_cmd_unix_sock_path
);
764 * This thread manage the application socket communication
766 static void *thread_manage_apps(void *data
)
769 struct pollfd pollfd
[2];
771 /* TODO: Something more elegant is needed but fine for now */
772 /* FIXME: change all types to either uint8_t, uint32_t, uint64_t
773 * for 32-bit vs 64-bit compat processes. */
774 /* replicate in ust with version number */
776 int reg
; /* 1:register, 0:unregister */
781 DBG("[thread] Manage apps started");
783 ret
= lttcomm_listen_unix_sock(apps_sock
);
788 /* First fd is always the quit pipe */
789 pollfd
[0].fd
= thread_quit_pipe
[0];
792 pollfd
[1].fd
= apps_sock
;
793 pollfd
[1].events
= POLLIN
;
795 /* Notify all applications to register */
796 notify_apps(default_global_apps_pipe
);
799 DBG("Accepting application registration");
801 /* Inifinite blocking call, waiting for transmission */
802 ret
= poll(pollfd
, 2, -1);
804 perror("poll apps thread");
808 /* Thread quit pipe has been closed. Killing thread. */
809 if (pollfd
[0].revents
== POLLNVAL
) {
811 } else if (pollfd
[1].revents
== POLLERR
) {
812 ERR("Apps socket poll error");
816 sock
= lttcomm_accept_unix_sock(apps_sock
);
822 * Basic recv here to handle the very simple data
823 * that the libust send to register (reg_msg).
825 ret
= recv(sock
, ®_msg
, sizeof(reg_msg
), 0);
831 /* Add application to the global traceable list */
832 if (reg_msg
.reg
== 1) {
834 ret
= register_traceable_app(reg_msg
.pid
, reg_msg
.uid
);
836 /* register_traceable_app only return an error with
837 * ENOMEM. At this point, we better stop everything.
843 unregister_traceable_app(reg_msg
.pid
);
848 DBG("Apps thread dying");
856 unlink(apps_unix_sock_path
);
861 * spawn_kconsumerd_thread
863 * Start the thread_manage_kconsumerd. This must be done after a kconsumerd
864 * exec or it will fails.
866 static int spawn_kconsumerd_thread(void)
870 /* Setup semaphore */
871 sem_init(&kconsumerd_sem
, 0, 0);
873 ret
= pthread_create(&kconsumerd_thread
, NULL
, thread_manage_kconsumerd
, (void *) NULL
);
875 perror("pthread_create kconsumerd");
879 /* Wait for the kconsumerd thread to be ready */
880 sem_wait(&kconsumerd_sem
);
882 if (kconsumerd_pid
== 0) {
883 ERR("Kconsumerd did not start");
890 ret
= LTTCOMM_KERN_CONSUMER_FAIL
;
897 * Fork and exec a kernel consumer daemon (kconsumerd).
899 * NOTE: It is very important to fork a kconsumerd BEFORE opening any kernel
900 * file descriptor using the libkernelctl or kernel-ctl functions. So, a
901 * kernel consumer MUST only be spawned before creating a kernel session.
903 * Return pid if successful else -1.
905 static pid_t
spawn_kconsumerd(void)
909 const char *verbosity
;
911 DBG("Spawning kconsumerd");
918 if (opt_verbose
> 1) {
919 verbosity
= "--verbose";
921 verbosity
= "--quiet";
923 execl(INSTALL_BIN_PATH
"/ltt-kconsumerd", "ltt-kconsumerd", verbosity
, NULL
);
925 perror("kernel start consumer exec");
928 } else if (pid
> 0) {
932 perror("kernel start consumer fork");
944 * Spawn the kconsumerd daemon and session daemon thread.
946 static int start_kconsumerd(void)
950 pthread_mutex_lock(&kconsumerd_pid_mutex
);
951 if (kconsumerd_pid
!= 0) {
952 pthread_mutex_unlock(&kconsumerd_pid_mutex
);
956 ret
= spawn_kconsumerd();
958 ERR("Spawning kconsumerd failed");
959 ret
= LTTCOMM_KERN_CONSUMER_FAIL
;
960 pthread_mutex_unlock(&kconsumerd_pid_mutex
);
964 /* Setting up the global kconsumerd_pid */
965 kconsumerd_pid
= ret
;
966 pthread_mutex_unlock(&kconsumerd_pid_mutex
);
968 DBG("Kconsumerd pid %d", ret
);
970 DBG("Spawning kconsumerd thread");
971 ret
= spawn_kconsumerd_thread();
973 ERR("Fatal error spawning kconsumerd thread");
985 * modprobe_kernel_modules
987 static int modprobe_kernel_modules(void)
992 while (kernel_modules_list
[i
] != NULL
) {
993 ret
= snprintf(modprobe
, sizeof(modprobe
), "/sbin/modprobe %s",
994 kernel_modules_list
[i
]);
996 perror("snprintf modprobe");
999 ret
= system(modprobe
);
1001 ERR("Unable to load module %s", kernel_modules_list
[i
]);
1003 DBG("Modprobe successfully %s", kernel_modules_list
[i
]);
1014 static int mount_debugfs(char *path
)
1017 char *type
= "debugfs";
1019 ret
= mkdir_recursive(path
, S_IRWXU
| S_IRWXG
);
1024 ret
= mount(type
, path
, type
, 0, NULL
);
1026 perror("mount debugfs");
1030 DBG("Mounted debugfs successfully at %s", path
);
1037 * init_kernel_tracer
1039 * Setup necessary data for kernel tracer action.
1041 static void init_kernel_tracer(void)
1044 char *proc_mounts
= "/proc/mounts";
1046 char *debugfs_path
= NULL
, *lttng_path
;
1049 /* Detect debugfs */
1050 fp
= fopen(proc_mounts
, "r");
1052 ERR("Unable to probe %s", proc_mounts
);
1056 while (fgets(line
, sizeof(line
), fp
) != NULL
) {
1057 if (strstr(line
, "debugfs") != NULL
) {
1058 /* Remove first string */
1060 /* Dup string here so we can reuse line later on */
1061 debugfs_path
= strdup(strtok(NULL
, " "));
1062 DBG("Got debugfs path : %s", debugfs_path
);
1069 /* Mount debugfs if needded */
1070 if (debugfs_path
== NULL
) {
1071 ret
= asprintf(&debugfs_path
, "/mnt/debugfs");
1073 perror("asprintf debugfs path");
1076 ret
= mount_debugfs(debugfs_path
);
1082 /* Modprobe lttng kernel modules */
1083 ret
= modprobe_kernel_modules();
1088 /* Setup lttng kernel path */
1089 ret
= asprintf(<tng_path
, "%s/lttng", debugfs_path
);
1091 perror("asprintf lttng path");
1095 /* Open debugfs lttng */
1096 kernel_tracer_fd
= open(lttng_path
, O_RDWR
);
1097 if (kernel_tracer_fd
< 0) {
1098 DBG("Failed to open %s", lttng_path
);
1104 DBG("Kernel tracer fd %d", kernel_tracer_fd
);
1114 WARN("No kernel tracer available");
1115 kernel_tracer_fd
= 0;
1120 * start_kernel_trace
1122 * Start tracing by creating trace directory and sending FDs to the kernel
1125 static int start_kernel_trace(struct ltt_kernel_session
*session
)
1129 if (session
->kconsumer_fds_sent
== 0) {
1130 ret
= send_kconsumerd_fds(kconsumerd_cmd_sock
, session
);
1132 ERR("Send kconsumerd fds failed");
1133 ret
= LTTCOMM_KERN_CONSUMER_FAIL
;
1137 session
->kconsumer_fds_sent
= 1;
1145 * Notify kernel thread to update it's pollfd.
1147 static int notify_kernel_pollfd(void)
1151 /* Inform kernel thread of the new kernel channel */
1152 ret
= write(kernel_poll_pipe
[1], "!", 1);
1154 perror("write kernel poll pipe");
1161 * init_default_channel
1163 * Allocate a channel structure and fill it.
1165 static struct lttng_channel
*init_default_channel(void)
1167 struct lttng_channel
*chan
;
1169 chan
= malloc(sizeof(struct lttng_channel
));
1171 perror("init channel malloc");
1175 if (snprintf(chan
->name
, NAME_MAX
, DEFAULT_CHANNEL_NAME
) < 0) {
1176 perror("snprintf defautl channel name");
1180 chan
->attr
.overwrite
= DEFAULT_CHANNEL_OVERWRITE
;
1181 chan
->attr
.subbuf_size
= DEFAULT_CHANNEL_SUBBUF_SIZE
;
1182 chan
->attr
.num_subbuf
= DEFAULT_CHANNEL_SUBBUF_NUM
;
1183 chan
->attr
.switch_timer_interval
= DEFAULT_CHANNEL_SWITCH_TIMER
;
1184 chan
->attr
.read_timer_interval
= DEFAULT_CHANNEL_READ_TIMER
;
1185 chan
->attr
.output
= DEFAULT_KERNEL_CHANNEL_OUTPUT
;
1192 * create_kernel_session
1194 * Create a kernel tracer session then create the default channel.
1196 static int create_kernel_session(struct ltt_session
*session
)
1200 DBG("Creating kernel session");
1202 ret
= kernel_create_session(session
, kernel_tracer_fd
);
1204 ret
= LTTCOMM_KERN_SESS_FAIL
;
1208 ret
= mkdir_recursive(session
->path
, S_IRWXU
| S_IRWXG
);
1210 if (ret
!= EEXIST
) {
1211 ERR("Trace directory creation error");
1221 * Using the session list, filled a lttng_session array to send back to the
1222 * client for session listing.
1224 * The session list lock MUST be acquired before calling this function. Use
1225 * lock_session_list() and unlock_session_list().
1227 static void list_lttng_sessions(struct lttng_session
*sessions
)
1230 struct ltt_session
*session
;
1232 DBG("Getting all available session");
1234 * Iterate over session list and append data after the control struct in
1237 cds_list_for_each_entry(session
, &session_list_ptr
->head
, list
) {
1238 strncpy(sessions
[i
].path
, session
->path
, PATH_MAX
);
1239 strncpy(sessions
[i
].name
, session
->name
, NAME_MAX
);
1245 * process_client_msg
1247 * Process the command requested by the lttng client within the command
1248 * context structure. This function make sure that the return structure (llm)
1249 * is set and ready for transmission before returning.
1251 * Return any error encountered or 0 for success.
1253 static int process_client_msg(struct command_ctx
*cmd_ctx
)
1255 int ret
= LTTCOMM_OK
;
1257 DBG("Processing client command %d", cmd_ctx
->lsm
->cmd_type
);
1259 /* Listing commands don't need a session */
1260 switch (cmd_ctx
->lsm
->cmd_type
) {
1261 case LTTNG_CREATE_SESSION
:
1262 case LTTNG_LIST_SESSIONS
:
1263 case LTTNG_LIST_EVENTS
:
1264 case LTTNG_KERNEL_LIST_EVENTS
:
1265 case LTTNG_LIST_TRACEABLE_APPS
:
1268 DBG("Getting session %s by name", cmd_ctx
->lsm
->session_name
);
1269 cmd_ctx
->session
= find_session_by_name(cmd_ctx
->lsm
->session_name
);
1270 if (cmd_ctx
->session
== NULL
) {
1271 /* If session name not found */
1272 if (cmd_ctx
->lsm
->session_name
!= NULL
) {
1273 ret
= LTTCOMM_SESS_NOT_FOUND
;
1274 } else { /* If no session name specified */
1275 ret
= LTTCOMM_SELECT_SESS
;
1279 /* Acquire lock for the session */
1280 lock_session(cmd_ctx
->session
);
1286 * Check kernel command for kernel session.
1288 switch (cmd_ctx
->lsm
->cmd_type
) {
1289 case LTTNG_KERNEL_ADD_CONTEXT
:
1290 case LTTNG_KERNEL_DISABLE_ALL_EVENT
:
1291 case LTTNG_KERNEL_DISABLE_CHANNEL
:
1292 case LTTNG_KERNEL_DISABLE_EVENT
:
1293 case LTTNG_KERNEL_ENABLE_ALL_EVENT
:
1294 case LTTNG_KERNEL_ENABLE_CHANNEL
:
1295 case LTTNG_KERNEL_ENABLE_EVENT
:
1296 case LTTNG_KERNEL_LIST_EVENTS
:
1297 /* Kernel tracer check */
1298 if (kernel_tracer_fd
== 0) {
1299 init_kernel_tracer();
1300 if (kernel_tracer_fd
== 0) {
1301 ret
= LTTCOMM_KERN_NA
;
1306 /* Need a session for kernel command */
1307 if (cmd_ctx
->lsm
->cmd_type
!= LTTNG_KERNEL_LIST_EVENTS
&&
1308 cmd_ctx
->session
->kernel_session
== NULL
) {
1310 ret
= create_kernel_session(cmd_ctx
->session
);
1312 ret
= LTTCOMM_KERN_SESS_FAIL
;
1316 /* Start the kernel consumer daemon */
1317 if (kconsumerd_pid
== 0) {
1318 ret
= start_kconsumerd();
1327 /* Connect to ust apps if available pid */
1328 if (cmd_ctx
->lsm
->pid
> 0) {
1329 /* Connect to app using ustctl API */
1330 cmd_ctx
->ust_sock
= ust_connect_app(cmd_ctx
->lsm
->pid
);
1331 if (cmd_ctx
->ust_sock
< 0) {
1332 ret
= LTTCOMM_NO_TRACEABLE
;
1336 #endif /* DISABLED */
1338 /* Process by command type */
1339 switch (cmd_ctx
->lsm
->cmd_type
) {
1340 case LTTNG_KERNEL_ADD_CONTEXT
:
1342 int found
= 0, no_event
= 0;
1343 struct ltt_kernel_channel
*chan
;
1344 struct ltt_kernel_event
*event
;
1345 struct lttng_kernel_context ctx
;
1347 /* Setup lttng message with no payload */
1348 ret
= setup_lttng_msg(cmd_ctx
, 0);
1353 /* Check if event name is given */
1354 if (strlen(cmd_ctx
->lsm
->u
.context
.event_name
) == 0) {
1358 /* Create Kernel context */
1359 ctx
.ctx
= cmd_ctx
->lsm
->u
.context
.ctx
.ctx
;
1360 ctx
.u
.perf_counter
.type
= cmd_ctx
->lsm
->u
.context
.ctx
.u
.perf_counter
.type
;
1361 ctx
.u
.perf_counter
.config
= cmd_ctx
->lsm
->u
.context
.ctx
.u
.perf_counter
.config
;
1362 strncpy(ctx
.u
.perf_counter
.name
,
1363 cmd_ctx
->lsm
->u
.context
.ctx
.u
.perf_counter
.name
,
1364 sizeof(ctx
.u
.perf_counter
.name
));
1366 if (strlen(cmd_ctx
->lsm
->u
.context
.channel_name
) == 0) {
1367 /* Go over all channels */
1368 DBG("Adding context to all channels");
1369 cds_list_for_each_entry(chan
,
1370 &cmd_ctx
->session
->kernel_session
->channel_list
.head
, list
) {
1372 ret
= kernel_add_channel_context(chan
, &ctx
);
1377 event
= get_kernel_event_by_name(cmd_ctx
->lsm
->u
.context
.event_name
, chan
);
1378 if (event
!= NULL
) {
1379 ret
= kernel_add_event_context(event
, &ctx
);
1381 ret
= LTTCOMM_KERN_CONTEXT_FAIL
;
1390 chan
= get_kernel_channel_by_name(cmd_ctx
->lsm
->u
.context
.channel_name
,
1391 cmd_ctx
->session
->kernel_session
);
1393 ret
= LTTCOMM_KERN_CHAN_NOT_FOUND
;
1398 ret
= kernel_add_channel_context(chan
, &ctx
);
1400 ret
= LTTCOMM_KERN_CONTEXT_FAIL
;
1404 event
= get_kernel_event_by_name(cmd_ctx
->lsm
->u
.context
.event_name
, chan
);
1405 if (event
!= NULL
) {
1406 ret
= kernel_add_event_context(event
, &ctx
);
1408 ret
= LTTCOMM_KERN_CONTEXT_FAIL
;
1415 if (!found
&& !no_event
) {
1416 ret
= LTTCOMM_NO_EVENT
;
1423 case LTTNG_KERNEL_DISABLE_CHANNEL
:
1425 struct ltt_kernel_channel
*chan
;
1427 /* Setup lttng message with no payload */
1428 ret
= setup_lttng_msg(cmd_ctx
, 0);
1433 chan
= get_kernel_channel_by_name(cmd_ctx
->lsm
->u
.disable
.channel_name
,
1434 cmd_ctx
->session
->kernel_session
);
1436 ret
= LTTCOMM_KERN_CHAN_NOT_FOUND
;
1438 } else if (chan
->enabled
== 1) {
1439 ret
= kernel_disable_channel(chan
);
1441 if (ret
!= EEXIST
) {
1442 ret
= LTTCOMM_KERN_CHAN_DISABLE_FAIL
;
1448 kernel_wait_quiescent(kernel_tracer_fd
);
1452 case LTTNG_KERNEL_DISABLE_EVENT
:
1454 struct ltt_kernel_channel
*chan
;
1455 struct ltt_kernel_event
*ev
;
1457 /* Setup lttng message with no payload */
1458 ret
= setup_lttng_msg(cmd_ctx
, 0);
1463 chan
= get_kernel_channel_by_name(cmd_ctx
->lsm
->u
.disable
.channel_name
,
1464 cmd_ctx
->session
->kernel_session
);
1466 ret
= LTTCOMM_KERN_CHAN_NOT_FOUND
;
1470 ev
= get_kernel_event_by_name(cmd_ctx
->lsm
->u
.disable
.name
, chan
);
1472 DBG("Disabling kernel event %s for channel %s.",
1473 cmd_ctx
->lsm
->u
.disable
.name
, cmd_ctx
->lsm
->u
.disable
.channel_name
);
1474 ret
= kernel_disable_event(ev
);
1476 ret
= LTTCOMM_KERN_ENABLE_FAIL
;
1481 kernel_wait_quiescent(kernel_tracer_fd
);
1485 case LTTNG_KERNEL_DISABLE_ALL_EVENT
:
1487 struct ltt_kernel_channel
*chan
;
1488 struct ltt_kernel_event
*ev
;
1490 /* Setup lttng message with no payload */
1491 ret
= setup_lttng_msg(cmd_ctx
, 0);
1496 DBG("Disabling all enabled kernel events");
1498 chan
= get_kernel_channel_by_name(cmd_ctx
->lsm
->u
.disable
.channel_name
,
1499 cmd_ctx
->session
->kernel_session
);
1501 ret
= LTTCOMM_KERN_CHAN_NOT_FOUND
;
1505 /* For each event in the kernel session */
1506 cds_list_for_each_entry(ev
, &chan
->events_list
.head
, list
) {
1507 DBG("Disabling kernel event %s for channel %s.",
1508 ev
->event
->name
, cmd_ctx
->lsm
->u
.disable
.channel_name
);
1509 ret
= kernel_disable_event(ev
);
1515 /* Quiescent wait after event disable */
1516 kernel_wait_quiescent(kernel_tracer_fd
);
1520 case LTTNG_KERNEL_ENABLE_CHANNEL
:
1522 struct ltt_kernel_channel
*chan
;
1524 /* Setup lttng message with no payload */
1525 ret
= setup_lttng_msg(cmd_ctx
, 0);
1530 chan
= get_kernel_channel_by_name(cmd_ctx
->lsm
->u
.enable
.channel_name
,
1531 cmd_ctx
->session
->kernel_session
);
1533 /* Channel not found, creating it */
1534 DBG("Creating kernel channel");
1536 ret
= kernel_create_channel(cmd_ctx
->session
->kernel_session
,
1537 &cmd_ctx
->lsm
->u
.channel
.chan
, cmd_ctx
->session
->path
);
1539 ret
= LTTCOMM_KERN_CHAN_FAIL
;
1543 /* Notify kernel thread that there is a new channel */
1544 ret
= notify_kernel_pollfd();
1546 ret
= LTTCOMM_FATAL
;
1549 } else if (chan
->enabled
== 0) {
1550 ret
= kernel_enable_channel(chan
);
1552 if (ret
!= EEXIST
) {
1553 ret
= LTTCOMM_KERN_CHAN_ENABLE_FAIL
;
1559 kernel_wait_quiescent(kernel_tracer_fd
);
1563 case LTTNG_KERNEL_ENABLE_EVENT
:
1566 struct ltt_kernel_channel
*kchan
;
1567 struct ltt_kernel_event
*ev
;
1568 struct lttng_channel
*chan
;
1570 /* Setup lttng message with no payload */
1571 ret
= setup_lttng_msg(cmd_ctx
, 0);
1576 channel_name
= cmd_ctx
->lsm
->u
.enable
.channel_name
;
1579 kchan
= get_kernel_channel_by_name(channel_name
,
1580 cmd_ctx
->session
->kernel_session
);
1581 if (kchan
== NULL
) {
1582 DBG("Creating default channel");
1584 chan
= init_default_channel();
1586 ret
= LTTCOMM_FATAL
;
1590 ret
= kernel_create_channel(cmd_ctx
->session
->kernel_session
,
1591 chan
, cmd_ctx
->session
->path
);
1593 ret
= LTTCOMM_KERN_CHAN_FAIL
;
1597 } while (kchan
== NULL
);
1599 ev
= get_kernel_event_by_name(cmd_ctx
->lsm
->u
.enable
.event
.name
, kchan
);
1601 DBG("Creating kernel event %s for channel %s.",
1602 cmd_ctx
->lsm
->u
.enable
.event
.name
, channel_name
);
1603 ret
= kernel_create_event(&cmd_ctx
->lsm
->u
.enable
.event
, kchan
);
1605 DBG("Enabling kernel event %s for channel %s.",
1606 cmd_ctx
->lsm
->u
.enable
.event
.name
, channel_name
);
1607 ret
= kernel_enable_event(ev
);
1608 if (ret
== -EEXIST
) {
1609 ret
= LTTCOMM_KERN_EVENT_EXIST
;
1615 ret
= LTTCOMM_KERN_ENABLE_FAIL
;
1619 kernel_wait_quiescent(kernel_tracer_fd
);
1623 case LTTNG_KERNEL_ENABLE_ALL_EVENT
:
1626 char *event_list
, *event
, *ptr
, *channel_name
;
1627 struct ltt_kernel_channel
*kchan
;
1628 struct ltt_kernel_event
*ev
;
1629 struct lttng_event ev_attr
;
1630 struct lttng_channel
*chan
;
1632 /* Setup lttng message with no payload */
1633 ret
= setup_lttng_msg(cmd_ctx
, 0);
1638 DBG("Enabling all kernel event");
1640 channel_name
= cmd_ctx
->lsm
->u
.enable
.channel_name
;
1643 kchan
= get_kernel_channel_by_name(channel_name
,
1644 cmd_ctx
->session
->kernel_session
);
1645 if (kchan
== NULL
) {
1646 DBG("Creating default channel");
1648 chan
= init_default_channel();
1650 ret
= LTTCOMM_FATAL
;
1654 ret
= kernel_create_channel(cmd_ctx
->session
->kernel_session
,
1655 chan
, cmd_ctx
->session
->path
);
1657 ret
= LTTCOMM_KERN_CHAN_FAIL
;
1661 } while (kchan
== NULL
);
1663 /* For each event in the kernel session */
1664 cds_list_for_each_entry(ev
, &kchan
->events_list
.head
, list
) {
1665 DBG("Enabling kernel event %s for channel %s.",
1666 ev
->event
->name
, channel_name
);
1667 ret
= kernel_enable_event(ev
);
1673 size
= kernel_list_events(kernel_tracer_fd
, &event_list
);
1675 ret
= LTTCOMM_KERN_LIST_FAIL
;
1680 while ((size
= sscanf(ptr
, "event { name = %m[^;]; };%n\n", &event
, &pos
)) == 1) {
1681 ev
= get_kernel_event_by_name(event
, kchan
);
1683 strncpy(ev_attr
.name
, event
, LTTNG_SYM_NAME_LEN
);
1684 /* Default event type for enable all */
1685 ev_attr
.type
= LTTNG_EVENT_TRACEPOINT
;
1686 /* Enable each single tracepoint event */
1687 ret
= kernel_create_event(&ev_attr
, kchan
);
1689 /* Ignore error here and continue */
1693 /* Move pointer to the next line */
1700 /* Quiescent wait after event enable */
1701 kernel_wait_quiescent(kernel_tracer_fd
);
1705 case LTTNG_KERNEL_LIST_EVENTS
:
1710 DBG("Listing kernel events");
1712 size
= kernel_list_events(kernel_tracer_fd
, &event_list
);
1714 ret
= LTTCOMM_KERN_LIST_FAIL
;
1719 * Setup lttng message with payload size set to the event list size in
1720 * bytes and then copy list into the llm payload.
1722 ret
= setup_lttng_msg(cmd_ctx
, size
);
1727 /* Copy event list into message payload */
1728 memcpy(cmd_ctx
->llm
->payload
, event_list
, size
);
1735 case LTTNG_START_TRACE
:
1737 struct ltt_kernel_channel
*chan
;
1739 /* Setup lttng message with no payload */
1740 ret
= setup_lttng_msg(cmd_ctx
, 0);
1745 /* Kernel tracing */
1746 if (cmd_ctx
->session
->kernel_session
!= NULL
) {
1747 if (cmd_ctx
->session
->kernel_session
->metadata
== NULL
) {
1748 DBG("Open kernel metadata");
1749 ret
= kernel_open_metadata(cmd_ctx
->session
->kernel_session
,
1750 cmd_ctx
->session
->path
);
1752 ret
= LTTCOMM_KERN_META_FAIL
;
1757 if (cmd_ctx
->session
->kernel_session
->metadata_stream_fd
== 0) {
1758 DBG("Opening kernel metadata stream");
1759 if (cmd_ctx
->session
->kernel_session
->metadata_stream_fd
== 0) {
1760 ret
= kernel_open_metadata_stream(cmd_ctx
->session
->kernel_session
);
1762 ERR("Kernel create metadata stream failed");
1763 ret
= LTTCOMM_KERN_STREAM_FAIL
;
1769 /* For each channel */
1770 cds_list_for_each_entry(chan
, &cmd_ctx
->session
->kernel_session
->channel_list
.head
, list
) {
1771 if (chan
->stream_count
== 0) {
1772 ret
= kernel_open_channel_stream(chan
);
1774 ERR("Kernel create channel stream failed");
1775 ret
= LTTCOMM_KERN_STREAM_FAIL
;
1778 /* Update the stream global counter */
1779 cmd_ctx
->session
->kernel_session
->stream_count_global
+= ret
;
1783 DBG("Start kernel tracing");
1784 ret
= kernel_start_session(cmd_ctx
->session
->kernel_session
);
1786 ERR("Kernel start session failed");
1787 ret
= LTTCOMM_KERN_START_FAIL
;
1791 ret
= start_kernel_trace(cmd_ctx
->session
->kernel_session
);
1793 ret
= LTTCOMM_KERN_START_FAIL
;
1797 /* Quiescent wait after starting trace */
1798 kernel_wait_quiescent(kernel_tracer_fd
);
1801 /* TODO: Start all UST traces */
1806 case LTTNG_STOP_TRACE
:
1808 struct ltt_kernel_channel
*chan
;
1809 /* Setup lttng message with no payload */
1810 ret
= setup_lttng_msg(cmd_ctx
, 0);
1816 if (cmd_ctx
->session
->kernel_session
!= NULL
) {
1817 DBG("Stop kernel tracing");
1819 ret
= kernel_metadata_flush_buffer(cmd_ctx
->session
->kernel_session
->metadata_stream_fd
);
1821 ERR("Kernel metadata flush failed");
1824 cds_list_for_each_entry(chan
, &cmd_ctx
->session
->kernel_session
->channel_list
.head
, list
) {
1825 ret
= kernel_flush_buffer(chan
);
1827 ERR("Kernel flush buffer error");
1831 ret
= kernel_stop_session(cmd_ctx
->session
->kernel_session
);
1833 ERR("Kernel stop session failed");
1834 ret
= LTTCOMM_KERN_STOP_FAIL
;
1838 /* Quiescent wait after stopping trace */
1839 kernel_wait_quiescent(kernel_tracer_fd
);
1842 /* TODO : User-space tracer */
1847 case LTTNG_CREATE_SESSION
:
1849 /* Setup lttng message with no payload */
1850 ret
= setup_lttng_msg(cmd_ctx
, 0);
1855 ret
= create_session(cmd_ctx
->lsm
->session_name
, cmd_ctx
->lsm
->path
);
1857 if (ret
== -EEXIST
) {
1858 ret
= LTTCOMM_EXIST_SESS
;
1860 ret
= LTTCOMM_FATAL
;
1868 case LTTNG_DESTROY_SESSION
:
1870 /* Setup lttng message with no payload */
1871 ret
= setup_lttng_msg(cmd_ctx
, 0);
1876 /* Clean kernel session teardown */
1877 teardown_kernel_session(cmd_ctx
->session
);
1879 ret
= destroy_session(cmd_ctx
->lsm
->session_name
);
1881 ret
= LTTCOMM_FATAL
;
1886 * Must notify the kernel thread here to update it's pollfd in order to
1887 * remove the channel(s)' fd just destroyed.
1889 ret
= notify_kernel_pollfd();
1891 ret
= LTTCOMM_FATAL
;
1899 case LTTNG_LIST_TRACES:
1901 unsigned int trace_count;
1903 trace_count = get_trace_count_per_session(cmd_ctx->session);
1904 if (trace_count == 0) {
1905 ret = LTTCOMM_NO_TRACE;
1909 ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_trace) * trace_count);
1914 get_traces_per_session(cmd_ctx->session,
1915 (struct lttng_trace *)(cmd_ctx->llm->payload));
1922 case UST_CREATE_TRACE:
1924 ret = setup_lttng_msg(cmd_ctx, 0);
1929 ret = ust_create_trace(cmd_ctx);
1936 case LTTNG_LIST_TRACEABLE_APPS
:
1938 unsigned int app_count
;
1940 app_count
= get_app_count();
1941 DBG("Traceable application count : %d", app_count
);
1942 if (app_count
== 0) {
1943 ret
= LTTCOMM_NO_APPS
;
1947 ret
= setup_lttng_msg(cmd_ctx
, sizeof(pid_t
) * app_count
);
1952 get_app_list_pids((pid_t
*)(cmd_ctx
->llm
->payload
));
1958 case UST_START_TRACE:
1960 ret = setup_lttng_msg(cmd_ctx, 0);
1965 ret = ust_start_trace(cmd_ctx);
1971 case UST_STOP_TRACE:
1973 ret = setup_lttng_msg(cmd_ctx, 0);
1978 ret = ust_stop_trace(cmd_ctx);
1985 case LTTNG_LIST_SESSIONS
:
1987 lock_session_list();
1989 if (session_list_ptr
->count
== 0) {
1990 ret
= LTTCOMM_NO_SESSION
;
1994 ret
= setup_lttng_msg(cmd_ctx
, sizeof(struct lttng_session
) *
1995 session_list_ptr
->count
);
2000 /* Filled the session array */
2001 list_lttng_sessions((struct lttng_session
*)(cmd_ctx
->llm
->payload
));
2003 unlock_session_list();
2009 /* Undefined command */
2010 ret
= setup_lttng_msg(cmd_ctx
, 0);
2019 /* Set return code */
2020 cmd_ctx
->llm
->ret_code
= ret
;
2022 if (cmd_ctx
->session
) {
2023 unlock_session(cmd_ctx
->session
);
2029 if (cmd_ctx
->llm
== NULL
) {
2030 DBG("Missing llm structure. Allocating one.");
2031 if (setup_lttng_msg(cmd_ctx
, 0) < 0) {
2035 /* Notify client of error */
2036 cmd_ctx
->llm
->ret_code
= ret
;
2039 if (cmd_ctx
->session
) {
2040 unlock_session(cmd_ctx
->session
);
2046 * thread_manage_clients
2048 * This thread manage all clients request using the unix
2049 * client socket for communication.
2051 static void *thread_manage_clients(void *data
)
2054 struct command_ctx
*cmd_ctx
= NULL
;
2055 struct pollfd pollfd
[2];
2057 DBG("[thread] Manage client started");
2059 ret
= lttcomm_listen_unix_sock(client_sock
);
2064 /* First fd is always the quit pipe */
2065 pollfd
[0].fd
= thread_quit_pipe
[0];
2068 pollfd
[1].fd
= client_sock
;
2069 pollfd
[1].events
= POLLIN
;
2071 /* Notify parent pid that we are ready
2072 * to accept command for client side.
2074 if (opt_sig_parent
) {
2075 kill(ppid
, SIGCHLD
);
2079 DBG("Accepting client command ...");
2081 /* Inifinite blocking call, waiting for transmission */
2082 ret
= poll(pollfd
, 2, -1);
2084 perror("poll client thread");
2088 /* Thread quit pipe has been closed. Killing thread. */
2089 if (pollfd
[0].revents
== POLLNVAL
) {
2091 } else if (pollfd
[1].revents
== POLLERR
) {
2092 ERR("Client socket poll error");
2096 sock
= lttcomm_accept_unix_sock(client_sock
);
2101 /* Allocate context command to process the client request */
2102 cmd_ctx
= malloc(sizeof(struct command_ctx
));
2104 /* Allocate data buffer for reception */
2105 cmd_ctx
->lsm
= malloc(sizeof(struct lttcomm_session_msg
));
2106 cmd_ctx
->llm
= NULL
;
2107 cmd_ctx
->session
= NULL
;
2110 * Data is received from the lttng client. The struct
2111 * lttcomm_session_msg (lsm) contains the command and data request of
2114 DBG("Receiving data from client ...");
2115 ret
= lttcomm_recv_unix_sock(sock
, cmd_ctx
->lsm
, sizeof(struct lttcomm_session_msg
));
2120 // TODO: Validate cmd_ctx including sanity check for security purpose.
2123 * This function dispatch the work to the kernel or userspace tracer
2124 * libs and fill the lttcomm_lttng_msg data structure of all the needed
2125 * informations for the client. The command context struct contains
2126 * everything this function may needs.
2128 ret
= process_client_msg(cmd_ctx
);
2130 /* TODO: Inform client somehow of the fatal error. At this point,
2131 * ret < 0 means that a malloc failed (ENOMEM). */
2132 /* Error detected but still accept command */
2133 clean_command_ctx(&cmd_ctx
);
2137 DBG("Sending response (size: %d, retcode: %d)",
2138 cmd_ctx
->lttng_msg_size
, cmd_ctx
->llm
->ret_code
);
2139 ret
= send_unix_sock(sock
, cmd_ctx
->llm
, cmd_ctx
->lttng_msg_size
);
2141 ERR("Failed to send data back to client");
2144 clean_command_ctx(&cmd_ctx
);
2146 /* End of transmission */
2151 DBG("Client thread dying");
2159 unlink(client_unix_sock_path
);
2161 clean_command_ctx(&cmd_ctx
);
2167 * usage function on stderr
2169 static void usage(void)
2171 fprintf(stderr
, "Usage: %s OPTIONS\n\nOptions:\n", progname
);
2172 fprintf(stderr
, " -h, --help Display this usage.\n");
2173 fprintf(stderr
, " -c, --client-sock PATH Specify path for the client unix socket\n");
2174 fprintf(stderr
, " -a, --apps-sock PATH Specify path for apps unix socket\n");
2175 fprintf(stderr
, " --kconsumerd-err-sock PATH Specify path for the kernel consumer error socket\n");
2176 fprintf(stderr
, " --kconsumerd-cmd-sock PATH Specify path for the kernel consumer command socket\n");
2177 fprintf(stderr
, " -d, --daemonize Start as a daemon.\n");
2178 fprintf(stderr
, " -g, --group NAME Specify the tracing group name. (default: tracing)\n");
2179 fprintf(stderr
, " -V, --version Show version number.\n");
2180 fprintf(stderr
, " -S, --sig-parent Send SIGCHLD to parent pid to notify readiness.\n");
2181 fprintf(stderr
, " -q, --quiet No output at all.\n");
2182 fprintf(stderr
, " -v, --verbose Verbose mode. Activate DBG() macro.\n");
2186 * daemon argument parsing
2188 static int parse_args(int argc
, char **argv
)
2192 static struct option long_options
[] = {
2193 { "client-sock", 1, 0, 'c' },
2194 { "apps-sock", 1, 0, 'a' },
2195 { "kconsumerd-cmd-sock", 1, 0, 0 },
2196 { "kconsumerd-err-sock", 1, 0, 0 },
2197 { "daemonize", 0, 0, 'd' },
2198 { "sig-parent", 0, 0, 'S' },
2199 { "help", 0, 0, 'h' },
2200 { "group", 1, 0, 'g' },
2201 { "version", 0, 0, 'V' },
2202 { "quiet", 0, 0, 'q' },
2203 { "verbose", 0, 0, 'v' },
2208 int option_index
= 0;
2209 c
= getopt_long(argc
, argv
, "dhqvVS" "a:c:g:s:E:C:", long_options
, &option_index
);
2216 fprintf(stderr
, "option %s", long_options
[option_index
].name
);
2218 fprintf(stderr
, " with arg %s\n", optarg
);
2222 snprintf(client_unix_sock_path
, PATH_MAX
, "%s", optarg
);
2225 snprintf(apps_unix_sock_path
, PATH_MAX
, "%s", optarg
);
2231 opt_tracing_group
= strdup(optarg
);
2237 fprintf(stdout
, "%s\n", VERSION
);
2243 snprintf(kconsumerd_err_unix_sock_path
, PATH_MAX
, "%s", optarg
);
2246 snprintf(kconsumerd_cmd_unix_sock_path
, PATH_MAX
, "%s", optarg
);
2252 /* Verbose level can increase using multiple -v */
2256 /* Unknown option or other error.
2257 * Error is printed by getopt, just return */
2266 * init_daemon_socket
2268 * Creates the two needed socket by the daemon.
2269 * apps_sock - The communication socket for all UST apps.
2270 * client_sock - The communication of the cli tool (lttng).
2272 static int init_daemon_socket()
2277 old_umask
= umask(0);
2279 /* Create client tool unix socket */
2280 client_sock
= lttcomm_create_unix_sock(client_unix_sock_path
);
2281 if (client_sock
< 0) {
2282 ERR("Create unix sock failed: %s", client_unix_sock_path
);
2287 /* File permission MUST be 660 */
2288 ret
= chmod(client_unix_sock_path
, S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
);
2290 ERR("Set file permissions failed: %s", client_unix_sock_path
);
2295 /* Create the application unix socket */
2296 apps_sock
= lttcomm_create_unix_sock(apps_unix_sock_path
);
2297 if (apps_sock
< 0) {
2298 ERR("Create unix sock failed: %s", apps_unix_sock_path
);
2303 /* File permission MUST be 666 */
2304 ret
= chmod(apps_unix_sock_path
, S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
| S_IROTH
| S_IWOTH
);
2306 ERR("Set file permissions failed: %s", apps_unix_sock_path
);
2317 * check_existing_daemon
2319 * Check if the global socket is available.
2320 * If yes, error is returned.
2322 static int check_existing_daemon()
2326 ret
= access(client_unix_sock_path
, F_OK
);
2328 ret
= access(apps_unix_sock_path
, F_OK
);
2337 * Set the tracing group gid onto the client socket.
2339 * Race window between mkdir and chown is OK because we are going from
2340 * more permissive (root.root) to les permissive (root.tracing).
2342 static int set_permissions(void)
2347 /* Decide which group name to use */
2348 (opt_tracing_group
!= NULL
) ?
2349 (grp
= getgrnam(opt_tracing_group
)) :
2350 (grp
= getgrnam(default_tracing_group
));
2354 WARN("No tracing group detected");
2357 ERR("Missing tracing group. Aborting execution.");
2363 /* Set lttng run dir */
2364 ret
= chown(LTTNG_RUNDIR
, 0, grp
->gr_gid
);
2366 ERR("Unable to set group on " LTTNG_RUNDIR
);
2370 /* lttng client socket path */
2371 ret
= chown(client_unix_sock_path
, 0, grp
->gr_gid
);
2373 ERR("Unable to set group on %s", client_unix_sock_path
);
2377 /* kconsumerd error socket path */
2378 ret
= chown(kconsumerd_err_unix_sock_path
, 0, grp
->gr_gid
);
2380 ERR("Unable to set group on %s", kconsumerd_err_unix_sock_path
);
2384 DBG("All permissions are set");
2391 * create_kernel_poll_pipe
2393 * Create the pipe used to wake up the kernel thread.
2395 static int create_kernel_poll_pipe(void)
2397 return pipe2(kernel_poll_pipe
, O_CLOEXEC
);
2401 * create_lttng_rundir
2403 * Create the lttng run directory needed for all
2404 * global sockets and pipe.
2406 static int create_lttng_rundir(void)
2410 ret
= mkdir(LTTNG_RUNDIR
, S_IRWXU
| S_IRWXG
);
2412 if (errno
!= EEXIST
) {
2413 ERR("Unable to create " LTTNG_RUNDIR
);
2425 * set_kconsumerd_sockets
2427 * Setup sockets and directory needed by the kconsumerd
2428 * communication with the session daemon.
2430 static int set_kconsumerd_sockets(void)
2434 if (strlen(kconsumerd_err_unix_sock_path
) == 0) {
2435 snprintf(kconsumerd_err_unix_sock_path
, PATH_MAX
, KCONSUMERD_ERR_SOCK_PATH
);
2438 if (strlen(kconsumerd_cmd_unix_sock_path
) == 0) {
2439 snprintf(kconsumerd_cmd_unix_sock_path
, PATH_MAX
, KCONSUMERD_CMD_SOCK_PATH
);
2442 ret
= mkdir(KCONSUMERD_PATH
, S_IRWXU
| S_IRWXG
);
2444 if (errno
!= EEXIST
) {
2445 ERR("Failed to create " KCONSUMERD_PATH
);
2451 /* Create the kconsumerd error unix socket */
2452 kconsumerd_err_sock
= lttcomm_create_unix_sock(kconsumerd_err_unix_sock_path
);
2453 if (kconsumerd_err_sock
< 0) {
2454 ERR("Create unix sock failed: %s", kconsumerd_err_unix_sock_path
);
2459 /* File permission MUST be 660 */
2460 ret
= chmod(kconsumerd_err_unix_sock_path
, S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
);
2462 ERR("Set file permissions failed: %s", kconsumerd_err_unix_sock_path
);
2474 * Signal handler for the daemon
2476 static void sighandler(int sig
)
2480 DBG("SIGPIPE catched");
2483 DBG("SIGINT catched");
2487 DBG("SIGTERM catched");
2498 * set_signal_handler
2500 * Setup signal handler for :
2501 * SIGINT, SIGTERM, SIGPIPE
2503 static int set_signal_handler(void)
2506 struct sigaction sa
;
2509 if ((ret
= sigemptyset(&sigset
)) < 0) {
2510 perror("sigemptyset");
2514 sa
.sa_handler
= sighandler
;
2515 sa
.sa_mask
= sigset
;
2517 if ((ret
= sigaction(SIGTERM
, &sa
, NULL
)) < 0) {
2518 perror("sigaction");
2522 if ((ret
= sigaction(SIGINT
, &sa
, NULL
)) < 0) {
2523 perror("sigaction");
2527 if ((ret
= sigaction(SIGPIPE
, &sa
, NULL
)) < 0) {
2528 perror("sigaction");
2532 DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT");
2540 * Set open files limit to unlimited. This daemon can open a large number of
2541 * file descriptors in order to consumer multiple kernel traces.
2543 static void set_ulimit(void)
2548 /* The kernel does not allowed an infinite limit for open files */
2549 lim
.rlim_cur
= 65535;
2550 lim
.rlim_max
= 65535;
2552 ret
= setrlimit(RLIMIT_NOFILE
, &lim
);
2554 perror("failed to set open files limit");
2561 int main(int argc
, char **argv
)
2565 const char *home_path
;
2567 /* Create thread quit pipe */
2568 if (init_thread_quit_pipe() < 0) {
2572 /* Parse arguments */
2574 if ((ret
= parse_args(argc
, argv
) < 0)) {
2587 /* Check if daemon is UID = 0 */
2588 is_root
= !getuid();
2591 ret
= create_lttng_rundir();
2596 if (strlen(apps_unix_sock_path
) == 0) {
2597 snprintf(apps_unix_sock_path
, PATH_MAX
,
2598 DEFAULT_GLOBAL_APPS_UNIX_SOCK
);
2601 if (strlen(client_unix_sock_path
) == 0) {
2602 snprintf(client_unix_sock_path
, PATH_MAX
,
2603 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK
);
2606 home_path
= get_home_dir();
2607 if (home_path
== NULL
) {
2608 /* TODO: Add --socket PATH option */
2609 ERR("Can't get HOME directory for sockets creation.");
2613 if (strlen(apps_unix_sock_path
) == 0) {
2614 snprintf(apps_unix_sock_path
, PATH_MAX
,
2615 DEFAULT_HOME_APPS_UNIX_SOCK
, home_path
);
2618 /* Set the cli tool unix socket path */
2619 if (strlen(client_unix_sock_path
) == 0) {
2620 snprintf(client_unix_sock_path
, PATH_MAX
,
2621 DEFAULT_HOME_CLIENT_UNIX_SOCK
, home_path
);
2625 DBG("Client socket path %s", client_unix_sock_path
);
2626 DBG("Application socket path %s", apps_unix_sock_path
);
2629 * See if daemon already exist. If any of the two socket needed by the
2630 * daemon are present, this test fails. However, if the daemon is killed
2631 * with a SIGKILL, those unix socket must be unlinked by hand.
2633 if ((ret
= check_existing_daemon()) == 0) {
2634 ERR("Already running daemon.\n");
2636 * We do not goto error because we must not cleanup() because a daemon
2637 * is already running.
2642 /* After this point, we can safely call cleanup() so goto error is used */
2645 * These actions must be executed as root. We do that *after* setting up
2646 * the sockets path because we MUST make the check for another daemon using
2647 * those paths *before* trying to set the kernel consumer sockets and init
2651 ret
= set_kconsumerd_sockets();
2656 /* Setup kernel tracer */
2657 init_kernel_tracer();
2659 /* Set ulimit for open files */
2663 if (set_signal_handler() < 0) {
2667 /* Setup the needed unix socket */
2668 if (init_daemon_socket() < 0) {
2672 /* Set credentials to socket */
2673 if (is_root
&& (set_permissions() < 0)) {
2677 /* Get parent pid if -S, --sig-parent is specified. */
2678 if (opt_sig_parent
) {
2682 /* Setup the kernel pipe for waking up the kernel thread */
2683 if (create_kernel_poll_pipe() < 0) {
2688 * Get session list pointer. This pointer MUST NOT be free().
2689 * This list is statically declared in session.c
2691 session_list_ptr
= get_session_list();
2694 /* Create thread to manage the client socket */
2695 ret
= pthread_create(&client_thread
, NULL
, thread_manage_clients
, (void *) NULL
);
2697 perror("pthread_create");
2701 /* Create thread to manage application socket */
2702 ret
= pthread_create(&apps_thread
, NULL
, thread_manage_apps
, (void *) NULL
);
2704 perror("pthread_create");
2708 /* Create kernel thread to manage kernel event */
2709 ret
= pthread_create(&kernel_thread
, NULL
, thread_manage_kernel
, (void *) NULL
);
2711 perror("pthread_create");
2715 ret
= pthread_join(client_thread
, &status
);
2717 perror("pthread_join");