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; either version 2
7 * of the License, or (at your option) any later version.
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.
31 #include <sys/socket.h>
33 #include <sys/types.h>
36 #include <urcu/list.h> /* URCU list library (-lurcu) */
37 #include <ust/ustctl.h> /* UST control lib (-lust) */
38 #include <lttng/liblttngctl.h>
40 #include "liblttsessiondcomm.h"
41 #include "ltt-sessiond.h"
45 #include "traceable-app.h"
48 const char default_home_dir
[] = DEFAULT_HOME_DIR
;
49 const char default_tracing_group
[] = DEFAULT_TRACING_GROUP
;
50 const char default_ust_sock_dir
[] = DEFAULT_UST_SOCK_DIR
;
51 const char default_global_apps_pipe
[] = DEFAULT_GLOBAL_APPS_PIPE
;
53 /* Static functions */
54 static int check_existing_daemon(void);
55 static int connect_app(pid_t pid
);
56 static int init_daemon_socket(void);
57 static int notify_apps(const char* name
);
58 static int process_client_msg(int sock
, struct lttcomm_session_msg
*);
59 static int send_unix_sock(int sock
, void *buf
, size_t len
);
60 static int set_signal_handler(void);
61 static int set_socket_perms(void);
62 static int setup_data_buffer(char **buf
, size_t size
, struct lttcomm_lttng_msg
*llm
);
63 static void cleanup(void);
64 static void copy_common_data(struct lttcomm_lttng_msg
*llm
, struct lttcomm_session_msg
*lsm
);
65 static void sighandler(int sig
);
67 static void *thread_manage_clients(void *data
);
68 static void *thread_manage_apps(void *data
);
74 const char *opt_tracing_group
;
75 static int opt_sig_parent
;
76 static int opt_daemon
;
77 static int is_root
; /* Set to 1 if the daemon is running as root */
80 static char apps_unix_sock_path
[PATH_MAX
]; /* Global application Unix socket path */
81 static char client_unix_sock_path
[PATH_MAX
]; /* Global client Unix socket path */
83 static int client_socket
;
84 static int apps_socket
;
86 static struct ltt_session
*current_session
;
91 * This thread manage the application socket communication
93 static void *thread_manage_apps(void *data
)
97 /* TODO: Something more elegant is needed but fine for now */
99 int reg
; /* 1:register, 0:unregister */
104 DBG("[thread] Manage apps started");
106 /* Notify all applications to register */
107 notify_apps(default_global_apps_pipe
);
109 ret
= lttcomm_listen_unix_sock(apps_socket
);
115 /* Blocking call, waiting for transmission */
116 sock
= lttcomm_accept_unix_sock(apps_socket
);
121 /* Basic recv here to handle the very simple data
122 * that the libust send to register (reg_msg).
124 ret
= recv(sock
, ®_msg
, sizeof(reg_msg
), 0);
130 /* Add application to the global traceable list */
131 if (reg_msg
.reg
== 1) {
133 ret
= register_traceable_app(reg_msg
.pid
, reg_msg
.uid
);
135 /* register_traceable_app only return an error with
136 * ENOMEM. At this point, we better stop everything.
142 unregister_traceable_app(reg_msg
.pid
);
152 * thread_manage_clients
154 * This thread manage all clients request using the unix
155 * client socket for communication.
157 static void *thread_manage_clients(void *data
)
160 struct lttcomm_session_msg lsm
;
162 DBG("[thread] Manage client started");
164 ret
= lttcomm_listen_unix_sock(client_socket
);
169 /* Notify parent pid that we are ready
170 * to accept command for client side.
172 if (opt_sig_parent
) {
177 /* Blocking call, waiting for transmission */
178 sock
= lttcomm_accept_unix_sock(client_socket
);
184 * Data is received from the lttng client. The struct
185 * lttcomm_session_msg (lsm) contains the command and data
186 * request of the client.
188 ret
= lttcomm_recv_unix_sock(sock
, &lsm
, sizeof(lsm
));
193 /* This function dispatch the work to the LTTng or UST libs
194 * and then sends back the response to the client. This is needed
195 * because there might be more then one lttcomm_lttng_msg to
196 * send out so process_client_msg do both jobs.
198 ret
= process_client_msg(sock
, &lsm
);
200 /* Error detected but still accept command */
212 * Send data on a unix socket using the liblttsessiondcomm API.
214 * Return lttcomm error code.
216 static int send_unix_sock(int sock
, void *buf
, size_t len
)
218 /* Check valid length */
223 return lttcomm_send_unix_sock(sock
, buf
, len
);
229 * Return a socket connected to the libust communication socket
230 * of the application identified by the pid.
232 * If the pid is not found in the traceable list,
233 * return -1 to indicate error.
235 static int connect_app(pid_t pid
)
238 struct ltt_traceable_app
*lta
;
240 DBG("Connect to application pid %d", pid
);
242 lta
= find_app_by_pid(pid
);
248 sock
= ustctl_connect_pid(lta
->pid
);
250 ERR("Fail connecting to the PID %d\n", pid
);
259 * Notify apps by writing 42 to a named pipe using name.
260 * Every applications waiting for a ltt-sessiond will be notified
261 * and re-register automatically to the session daemon.
263 * Return open or write error value.
265 static int notify_apps(const char *name
)
270 DBG("Notify the global application pipe");
272 /* Try opening the global pipe */
273 fd
= open(name
, O_WRONLY
);
278 /* Notify by writing on the pipe */
279 ret
= write(fd
, "42", 2);
291 * Create an userspace trace using pid.
292 * This trace is then appended to the current session
295 static int ust_create_trace(pid_t pid
)
298 struct ltt_ust_trace
*trace
;
300 DBG("Creating trace for pid %d", pid
);
302 trace
= malloc(sizeof(struct ltt_ust_trace
));
312 /* NOTE: to be removed. Trace name will no longer be
313 * required for LTTng userspace tracer. For now, we set it
314 * to 'auto' for API compliance.
316 snprintf(trace
->name
, 5, "auto");
318 /* Connect to app using ustctl API */
319 sock
= connect_app(pid
);
321 ret
= LTTCOMM_NO_TRACEABLE
;
325 ret
= ustctl_create_trace(sock
, trace
->name
);
327 ret
= LTTCOMM_CREATE_FAIL
;
331 /* Check if current session is valid */
332 if (current_session
) {
333 cds_list_add(&trace
->list
, ¤t_session
->ust_traces
);
334 current_session
->ust_trace_count
++;
344 * Start a trace. This trace, identified by the pid, must be
345 * in the current session ust_traces list.
347 static int ust_start_trace(pid_t pid
)
350 struct ltt_ust_trace
*trace
;
352 DBG("Starting trace for pid %d", pid
);
354 trace
= find_session_ust_trace_by_pid(current_session
, pid
);
356 ret
= LTTCOMM_NO_TRACE
;
360 /* Connect to app using ustctl API */
361 sock
= connect_app(pid
);
363 ret
= LTTCOMM_NO_TRACEABLE
;
367 ret
= ustctl_start_trace(sock
, "auto");
369 ret
= LTTCOMM_START_FAIL
;
380 * Stop a trace. This trace, identified by the pid, must be
381 * in the current session ust_traces list.
383 static int ust_stop_trace(pid_t pid
)
386 struct ltt_ust_trace
*trace
;
388 DBG("Stopping trace for pid %d", pid
);
390 trace
= find_session_ust_trace_by_pid(current_session
, pid
);
392 ret
= LTTCOMM_NO_TRACE
;
396 /* Connect to app using ustctl API */
397 sock
= connect_app(pid
);
399 ret
= LTTCOMM_NO_TRACEABLE
;
403 ret
= ustctl_stop_trace(sock
, trace
->name
);
405 ret
= LTTCOMM_STOP_FAIL
;
416 * Copy common data between lttcomm_lttng_msg and lttcomm_session_msg
418 static void copy_common_data(struct lttcomm_lttng_msg
*llm
, struct lttcomm_session_msg
*lsm
)
420 llm
->cmd_type
= lsm
->cmd_type
;
424 if (!uuid_is_null(lsm
->session_id
)) {
425 uuid_copy(llm
->session_id
, lsm
->session_id
);
428 strncpy(llm
->trace_name
, lsm
->trace_name
, strlen(llm
->trace_name
));
429 llm
->trace_name
[strlen(llm
->trace_name
) - 1] = '\0';
435 * Setup the outgoing data buffer for the response
436 * data allocating the right amount of memory.
438 * Return total size of the buffer pointed by buf.
440 static int setup_data_buffer(char **buf
, size_t s_data
, struct lttcomm_lttng_msg
*llm
)
445 buf_size
= sizeof(struct lttcomm_lttng_msg
) + s_data
;
446 *buf
= malloc(buf_size
);
453 /* Setup lttcomm_lttng_msg data and copy
454 * it to the newly allocated buffer.
456 llm
->size_payload
= s_data
;
457 memcpy(*buf
, llm
, sizeof(struct lttcomm_lttng_msg
));
468 * This takes the lttcomm_session_msg struct and process the command requested
469 * by the client. It then creates response(s) and send it back to the
470 * given socket (sock).
472 * Return any error encountered or 0 for success.
474 static int process_client_msg(int sock
, struct lttcomm_session_msg
*lsm
)
479 char *send_buf
= NULL
;
480 struct lttcomm_lttng_msg llm
;
482 DBG("Processing client message");
484 /* Copy common data to identify the response
485 * on the lttng client side.
487 copy_common_data(&llm
, lsm
);
489 /* Check command that needs a session */
490 if (lsm
->cmd_type
!= LTTNG_CREATE_SESSION
&&
491 lsm
->cmd_type
!= LTTNG_LIST_SESSIONS
&&
492 lsm
->cmd_type
!= UST_LIST_APPS
)
494 current_session
= find_session_by_uuid(lsm
->session_id
);
495 if (current_session
== NULL
) {
496 ret
= LTTCOMM_SELECT_SESS
;
501 /* Default return code.
502 * In our world, everything is OK... right? ;)
504 llm
.ret_code
= LTTCOMM_OK
;
506 header_size
= sizeof(struct lttcomm_lttng_msg
);
508 /* Process by command type */
509 switch (lsm
->cmd_type
) {
510 case LTTNG_CREATE_SESSION
:
512 ret
= create_session(lsm
->session_name
, &llm
.session_id
);
515 ret
= LTTCOMM_EXIST_SESS
;
522 buf_size
= setup_data_buffer(&send_buf
, 0, &llm
);
530 case LTTNG_DESTROY_SESSION
:
532 ret
= destroy_session(&lsm
->session_id
);
534 ret
= LTTCOMM_NO_SESS
;
539 /* No auxiliary data so only send the llm struct. */
542 case LTTNG_LIST_TRACES
:
544 unsigned int trace_count
= get_trace_count_per_session(current_session
);
546 if (trace_count
== 0) {
547 ret
= LTTCOMM_NO_TRACE
;
551 buf_size
= setup_data_buffer(&send_buf
,
552 sizeof(struct lttng_trace
) * trace_count
, &llm
);
558 get_traces_per_session(current_session
, (struct lttng_trace
*)(send_buf
+ header_size
));
561 case UST_CREATE_TRACE
:
563 ret
= ust_create_trace(lsm
->pid
);
565 /* If -1 is returned from ust_create_trace, malloc
566 * failed so it's pretty much a fatal error.
572 /* No auxiliary data so only send the llm struct. */
577 unsigned int app_count
= get_app_count();
578 /* Stop right now if no apps */
579 if (app_count
== 0) {
580 ret
= LTTCOMM_NO_APPS
;
584 /* Setup data buffer and details for transmission */
585 buf_size
= setup_data_buffer(&send_buf
,
586 sizeof(pid_t
) * app_count
, &llm
);
592 get_app_list_pids((pid_t
*)(send_buf
+ header_size
));
596 case UST_START_TRACE
:
598 ret
= ust_start_trace(lsm
->pid
);
600 /* No auxiliary data so only send the llm struct. */
605 ret
= ust_stop_trace(lsm
->pid
);
607 /* No auxiliary data so only send the llm struct. */
610 case LTTNG_LIST_SESSIONS
:
612 unsigned int session_count
= get_session_count();
613 /* Stop right now if no session */
614 if (session_count
== 0) {
615 ret
= LTTCOMM_NO_SESS
;
619 /* Setup data buffer and details for transmission */
620 buf_size
= setup_data_buffer(&send_buf
,
621 (sizeof(struct lttng_session
) * session_count
), &llm
);
627 get_lttng_session((struct lttng_session
*)(send_buf
+ header_size
));
633 /* Undefined command */
639 ret
= send_unix_sock(sock
, send_buf
, buf_size
);
641 if (send_buf
!= NULL
) {
648 /* Notify client of error */
650 llm
.size_payload
= 0;
651 send_unix_sock(sock
, (void*) &llm
, sizeof(llm
));
657 * usage function on stderr
659 static void usage(void)
661 fprintf(stderr
, "Usage: %s OPTIONS\n\nOptions:\n", progname
);
662 fprintf(stderr
, " -h, --help Display this usage.\n");
663 fprintf(stderr
, " -c, --client-sock PATH Specify path for the client unix socket\n");
664 fprintf(stderr
, " -a, --apps-sock PATH Specify path for apps unix socket.\n");
665 fprintf(stderr
, " -d, --daemonize Start as a daemon.\n");
666 fprintf(stderr
, " -g, --group NAME Specify the tracing group name. (default: tracing)\n");
667 fprintf(stderr
, " -V, --version Show version number.\n");
668 fprintf(stderr
, " -S, --sig-parent Send SIGCHLD to parent pid to notify readiness.\n");
669 fprintf(stderr
, " -q, --quiet No output at all.\n");
670 fprintf(stderr
, " -v, --verbose Verbose mode. Activate DBG() macro.\n");
674 * daemon argument parsing
676 static int parse_args(int argc
, char **argv
)
680 static struct option long_options
[] = {
681 { "client-sock", 1, 0, 'c' },
682 { "apps-sock", 1, 0, 'a' },
683 { "daemonize", 0, 0, 'd' },
684 { "sig-parent", 0, 0, 'S' },
685 { "help", 0, 0, 'h' },
686 { "group", 1, 0, 'g' },
687 { "version", 0, 0, 'V' },
688 { "quiet", 0, 0, 'q' },
689 { "verbose", 0, 0, 'v' },
694 int option_index
= 0;
695 c
= getopt_long(argc
, argv
, "dhqvVS" "a:c:g:s:", long_options
, &option_index
);
702 fprintf(stderr
, "option %s", long_options
[option_index
].name
);
704 fprintf(stderr
, " with arg %s\n", optarg
);
708 snprintf(client_unix_sock_path
, PATH_MAX
, "%s", optarg
);
711 snprintf(apps_unix_sock_path
, PATH_MAX
, "%s", optarg
);
717 opt_tracing_group
= strdup(optarg
);
723 fprintf(stdout
, "%s\n", VERSION
);
735 /* Unknown option or other error.
736 * Error is printed by getopt, just return */
747 * Creates the two needed socket by the daemon.
748 * apps_socket - The communication socket for all UST apps.
749 * client_socket - The communication of the cli tool (lttng).
751 static int init_daemon_socket()
756 old_umask
= umask(0);
758 /* Create client tool unix socket */
759 client_socket
= lttcomm_create_unix_sock(client_unix_sock_path
);
760 if (client_socket
< 0) {
765 /* File permission MUST be 660 */
766 ret
= chmod(client_unix_sock_path
, S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
);
772 /* Create the application unix socket */
773 apps_socket
= lttcomm_create_unix_sock(apps_unix_sock_path
);
774 if (apps_socket
< 0) {
779 /* File permission MUST be 660 */
780 ret
= chmod(apps_unix_sock_path
, S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
| S_IROTH
| S_IWOTH
);
792 * check_existing_daemon
794 * Check if the global socket is available.
795 * If yes, error is returned.
797 static int check_existing_daemon()
801 ret
= access(client_unix_sock_path
, F_OK
);
803 ret
= access(apps_unix_sock_path
, F_OK
);
812 * Return pointer to home directory path using
813 * the env variable HOME.
817 static const char *get_home_dir(void)
819 const char *home_path
;
821 if ((home_path
= (const char *) getenv("HOME")) == NULL
) {
822 home_path
= default_home_dir
;
831 * Set the tracing group gid onto the client socket.
833 static int set_socket_perms(void)
838 /* Decide which group name to use */
839 (opt_tracing_group
!= NULL
) ?
840 (grp
= getgrnam(opt_tracing_group
)) :
841 (grp
= getgrnam(default_tracing_group
));
844 ERR("Missing tracing group. Aborting execution.\n");
849 ret
= chown(client_unix_sock_path
, 0, grp
->gr_gid
);
854 DBG("Sockets permissions set");
863 * Setup signal handler for :
864 * SIGINT, SIGTERM, SIGPIPE
866 static int set_signal_handler(void)
872 if ((ret
= sigemptyset(&sigset
)) < 0) {
873 perror("sigemptyset");
877 sa
.sa_handler
= sighandler
;
880 if ((ret
= sigaction(SIGTERM
, &sa
, NULL
)) < 0) {
885 if ((ret
= sigaction(SIGINT
, &sa
, NULL
)) < 0) {
890 if ((ret
= sigaction(SIGPIPE
, &sa
, NULL
)) < 0) {
895 DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT");
903 * Signal handler for the daemon
905 static void sighandler(int sig
)
909 DBG("SIGPIPE catched");
912 DBG("SIGINT catched");
916 DBG("SIGTERM catched");
929 * Cleanup the daemon on exit
931 static void cleanup()
936 MSG("\n%c[%d;%dm*** assert failed *** ==> %c[%dm", 27,1,31,27,0);
937 MSG("%c[%d;%dmMatthew, BEET driven development works!%c[%dm",27,1,33,27,0);
940 unlink(client_unix_sock_path
);
941 unlink(apps_unix_sock_path
);
947 int main(int argc
, char **argv
)
952 pthread_t threads
[2];
954 /* Parse arguments */
956 if ((ret
= parse_args(argc
, argv
) < 0)) {
969 /* Check if daemon is UID = 0 */
972 /* Set all sockets path */
974 if (strlen(apps_unix_sock_path
) == 0) {
975 (snprintf(apps_unix_sock_path
, PATH_MAX
,
976 DEFAULT_GLOBAL_APPS_UNIX_SOCK
));
979 if (strlen(client_unix_sock_path
) == 0) {
980 (snprintf(client_unix_sock_path
, PATH_MAX
,
981 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK
));
984 if (strlen(apps_unix_sock_path
) == 0) {
985 (snprintf(apps_unix_sock_path
, PATH_MAX
,
986 DEFAULT_HOME_APPS_UNIX_SOCK
, get_home_dir()));
989 /* Set the cli tool unix socket path */
990 if (strlen(client_unix_sock_path
) == 0) {
991 (snprintf(client_unix_sock_path
, PATH_MAX
,
992 DEFAULT_HOME_CLIENT_UNIX_SOCK
, get_home_dir()));
996 /* See if daemon already exist. If any of the two
997 * socket needed by the daemon are present, this test fails
999 if ((ret
= check_existing_daemon()) == 0) {
1000 ERR("Already running daemon.\n");
1001 /* We do not goto error because we must not
1002 * cleanup() because a daemon is already working.
1004 return EXIT_FAILURE
;
1007 if (set_signal_handler() < 0) {
1011 /* Setup the two needed unix socket */
1012 if (init_daemon_socket() < 0) {
1016 /* Set credentials to socket */
1017 if (is_root
&& (set_socket_perms() < 0)) {
1021 /* Get parent pid if -S, --sig-parent is specified. */
1022 if (opt_sig_parent
) {
1027 /* Create thread to manage the client socket */
1028 ret
= pthread_create(&threads
[0], NULL
, thread_manage_clients
, (void *) NULL
);
1030 perror("pthread_create");
1034 /* Create thread to manage application socket */
1035 ret
= pthread_create(&threads
[1], NULL
, thread_manage_apps
, (void *) NULL
);
1037 perror("pthread_create");
1041 for (i
= 0; i
< 2; i
++) {
1042 ret
= pthread_join(threads
[i
], &status
);
1044 perror("pthread_join");
1056 return EXIT_FAILURE
;