4 * Linux Trace Toolkit Control Library
6 * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
8 * This library is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU Lesser General Public License, version 2.1 only,
10 * as published by the Free Software Foundation.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public License
18 * along with this library; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
31 #include <common/common.h>
32 #include <common/defaults.h>
33 #include <common/sessiond-comm/sessiond-comm.h>
34 #include <common/uri.h>
35 #include <common/utils.h>
36 #include <lttng/lttng.h>
38 #include "filter/filter-ast.h"
39 #include "filter/filter-parser.h"
40 #include "filter/filter-bytecode.h"
41 #include "filter/memstream.h"
44 static const int print_xml
= 1;
45 #define dbg_printf(fmt, args...) \
46 printf("[debug liblttng-ctl] " fmt, ## args)
48 static const int print_xml
= 0;
49 #define dbg_printf(fmt, args...) \
51 /* do nothing but check printf format */ \
53 printf("[debug liblttnctl] " fmt, ## args); \
58 /* Socket to session daemon for communication */
59 static int sessiond_socket
;
60 static char sessiond_sock_path
[PATH_MAX
];
61 static char health_sock_path
[PATH_MAX
];
64 static char *tracing_group
;
70 * Those two variables are used by error.h to silent or control the verbosity of
71 * error message. They are global to the library so application linking with it
72 * are able to compile correctly and also control verbosity of the library.
75 int lttng_opt_verbose
;
78 * Compare two URL destination.
80 * Return 0 is equal else is not equal.
82 static int compare_destination(struct lttng_uri
*ctrl
, struct lttng_uri
*data
)
89 switch (ctrl
->dtype
) {
91 ret
= strncmp(ctrl
->dst
.ipv4
, data
->dst
.ipv4
, sizeof(ctrl
->dst
.ipv4
));
94 ret
= strncmp(ctrl
->dst
.ipv6
, data
->dst
.ipv6
, sizeof(ctrl
->dst
.ipv6
));
104 static void set_default_url_attr(struct lttng_uri
*uri
,
105 enum lttng_stream_type stype
)
108 if (uri
->dtype
!= LTTNG_DST_PATH
&& uri
->port
== 0) {
109 uri
->port
= (stype
== LTTNG_STREAM_CONTROL
) ?
110 DEFAULT_NETWORK_CONTROL_PORT
: DEFAULT_NETWORK_DATA_PORT
;
115 * Parse a string URL and creates URI(s) returning the size of the populated
118 static ssize_t
parse_str_urls_to_uri(const char *ctrl_url
, const char *data_url
,
119 struct lttng_uri
**uris
)
121 unsigned int equal
= 1, idx
= 0;
122 /* Add the "file://" size to the URL maximum size */
123 char url
[PATH_MAX
+ 7];
124 ssize_t size_ctrl
= 0, size_data
= 0, size
;
125 struct lttng_uri
*ctrl_uris
= NULL
, *data_uris
= NULL
;
126 struct lttng_uri
*tmp_uris
= NULL
;
128 /* No URL(s) is allowed. This means that the consumer will be disabled. */
129 if (ctrl_url
== NULL
&& data_url
== NULL
) {
133 /* Check if URLs are equal and if so, only use the control URL */
134 if (ctrl_url
&& data_url
) {
135 equal
= !strcmp(ctrl_url
, data_url
);
139 * Since we allow the str_url to be a full local filesystem path, we are
140 * going to create a valid file:// URL if it's the case.
142 * Check if first character is a '/' or else reject the URL.
144 if (ctrl_url
&& ctrl_url
[0] == '/') {
147 ret
= snprintf(url
, sizeof(url
), "file://%s", ctrl_url
);
149 PERROR("snprintf file url");
155 /* Parse the control URL if there is one */
157 size_ctrl
= uri_parse(ctrl_url
, &ctrl_uris
);
159 ERR("Unable to parse the URL %s", ctrl_url
);
163 /* At this point, we know there is at least one URI in the array */
164 set_default_url_attr(&ctrl_uris
[0], LTTNG_STREAM_CONTROL
);
166 if (ctrl_uris
[0].dtype
== LTTNG_DST_PATH
&& data_url
) {
167 ERR("Can not have a data URL when destination is file://");
171 /* URL are not equal but the control URL uses a net:// protocol */
172 if (size_ctrl
== 2) {
174 ERR("Control URL uses the net:// protocol and the data URL is "
175 "different. Not allowed.");
178 set_default_url_attr(&ctrl_uris
[1], LTTNG_STREAM_DATA
);
180 * The data_url and ctrl_url are equal and the ctrl_url
181 * contains a net:// protocol so we just skip the data part.
191 /* We have to parse the data URL in this case */
192 size_data
= uri_parse(data_url
, &data_uris
);
194 ERR("Unable to parse the URL %s", data_url
);
196 } else if (size_data
== 2) {
197 ERR("Data URL can not be set with the net[4|6]:// protocol");
201 set_default_url_attr(&data_uris
[0], LTTNG_STREAM_DATA
);
203 ret
= compare_destination(&ctrl_uris
[0], &data_uris
[0]);
205 ERR("Control and data destination mismatch");
210 /* Compute total size */
211 size
= size_ctrl
+ size_data
;
213 tmp_uris
= zmalloc(sizeof(struct lttng_uri
) * size
);
214 if (tmp_uris
== NULL
) {
215 PERROR("zmalloc uris");
220 /* It's possible the control URIs array contains more than one URI */
221 memcpy(tmp_uris
, ctrl_uris
, sizeof(struct lttng_uri
) * size_ctrl
);
227 memcpy(&tmp_uris
[idx
], data_uris
, sizeof(struct lttng_uri
));
244 * Copy string from src to dst and enforce null terminated byte.
246 static void copy_string(char *dst
, const char *src
, size_t len
)
249 strncpy(dst
, src
, len
);
250 /* Enforce the NULL terminated byte */
258 * Copy domain to lttcomm_session_msg domain.
260 * If domain is unknown, default domain will be the kernel.
262 static void copy_lttng_domain(struct lttng_domain
*dst
, struct lttng_domain
*src
)
266 case LTTNG_DOMAIN_KERNEL
:
267 case LTTNG_DOMAIN_UST
:
269 case LTTNG_DOMAIN_UST_EXEC_NAME:
270 case LTTNG_DOMAIN_UST_PID:
271 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
273 memcpy(dst
, src
, sizeof(struct lttng_domain
));
276 memset(dst
, 0, sizeof(struct lttng_domain
));
283 * Send lttcomm_session_msg to the session daemon.
285 * On success, returns the number of bytes sent (>=0)
286 * On error, returns -1
288 static int send_session_msg(struct lttcomm_session_msg
*lsm
)
293 ret
= -LTTNG_ERR_NO_SESSIOND
;
297 DBG("LSM cmd type : %d", lsm
->cmd_type
);
299 ret
= lttcomm_send_creds_unix_sock(sessiond_socket
, lsm
,
300 sizeof(struct lttcomm_session_msg
));
302 ret
= -LTTNG_ERR_FATAL
;
310 * Send var len data to the session daemon.
312 * On success, returns the number of bytes sent (>=0)
313 * On error, returns -1
315 static int send_session_varlen(void *data
, size_t len
)
320 ret
= -LTTNG_ERR_NO_SESSIOND
;
329 ret
= lttcomm_send_unix_sock(sessiond_socket
, data
, len
);
331 ret
= -LTTNG_ERR_FATAL
;
339 * Receive data from the sessiond socket.
341 * On success, returns the number of bytes received (>=0)
342 * On error, returns -1 (recvmsg() error) or -ENOTCONN
344 static int recv_data_sessiond(void *buf
, size_t len
)
349 ret
= -LTTNG_ERR_NO_SESSIOND
;
353 ret
= lttcomm_recv_unix_sock(sessiond_socket
, buf
, len
);
355 ret
= -LTTNG_ERR_FATAL
;
363 * Check if we are in the specified group.
365 * If yes return 1, else return -1.
367 static int check_tracing_group(const char *grp_name
)
369 struct group
*grp_tracing
; /* no free(). See getgrnam(3) */
371 int grp_list_size
, grp_id
, i
;
374 /* Get GID of group 'tracing' */
375 grp_tracing
= getgrnam(grp_name
);
377 /* If grp_tracing is NULL, the group does not exist. */
381 /* Get number of supplementary group IDs */
382 grp_list_size
= getgroups(0, NULL
);
383 if (grp_list_size
< 0) {
388 /* Alloc group list of the right size */
389 grp_list
= malloc(grp_list_size
* sizeof(gid_t
));
394 grp_id
= getgroups(grp_list_size
, grp_list
);
400 for (i
= 0; i
< grp_list_size
; i
++) {
401 if (grp_list
[i
] == grp_tracing
->gr_gid
) {
415 * Try connect to session daemon with sock_path.
417 * Return 0 on success, else -1
419 static int try_connect_sessiond(const char *sock_path
)
423 /* If socket exist, we check if the daemon listens for connect. */
424 ret
= access(sock_path
, F_OK
);
430 ret
= lttcomm_connect_unix_sock(sock_path
);
436 ret
= lttcomm_close_unix_sock(ret
);
438 perror("lttcomm_close_unix_sock");
448 * Set sessiond socket path by putting it in the global sessiond_sock_path
451 * Returns 0 on success, negative value on failure (the sessiond socket path
452 * is somehow too long or ENOMEM).
454 static int set_session_daemon_path(void)
456 int in_tgroup
= 0; /* In tracing group */
462 /* Are we in the tracing group ? */
463 in_tgroup
= check_tracing_group(tracing_group
);
466 if ((uid
== 0) || in_tgroup
) {
467 copy_string(sessiond_sock_path
, DEFAULT_GLOBAL_CLIENT_UNIX_SOCK
,
468 sizeof(sessiond_sock_path
));
476 ret
= try_connect_sessiond(sessiond_sock_path
);
480 /* Global session daemon not available... */
482 /* ...or not in tracing group (and not root), default */
485 * With GNU C < 2.1, snprintf returns -1 if the target buffer is too small;
486 * With GNU C >= 2.1, snprintf returns the required size (excluding closing null)
488 ret
= snprintf(sessiond_sock_path
, sizeof(sessiond_sock_path
),
489 DEFAULT_HOME_CLIENT_UNIX_SOCK
, utils_get_home_dir());
490 if ((ret
< 0) || (ret
>= sizeof(sessiond_sock_path
))) {
502 * Connect to the LTTng session daemon.
504 * On success, return 0. On error, return -1.
506 static int connect_sessiond(void)
510 ret
= set_session_daemon_path();
515 /* Connect to the sesssion daemon */
516 ret
= lttcomm_connect_unix_sock(sessiond_sock_path
);
521 sessiond_socket
= ret
;
531 * Clean disconnect from the session daemon.
532 * On success, return 0. On error, return -1.
534 static int disconnect_sessiond(void)
539 ret
= lttcomm_close_unix_sock(sessiond_socket
);
548 * Ask the session daemon a specific command and put the data into buf.
549 * Takes extra var. len. data as input to send to the session daemon.
551 * Return size of data (only payload, not header) or a negative error code.
553 static int ask_sessiond_varlen(struct lttcomm_session_msg
*lsm
,
554 void *vardata
, size_t varlen
, void **buf
)
559 struct lttcomm_lttng_msg llm
;
561 ret
= connect_sessiond();
563 ret
= -LTTNG_ERR_NO_SESSIOND
;
567 /* Send command to session daemon */
568 ret
= send_session_msg(lsm
);
570 /* Ret value is a valid lttng error code. */
573 /* Send var len data */
574 ret
= send_session_varlen(vardata
, varlen
);
576 /* Ret value is a valid lttng error code. */
580 /* Get header from data transmission */
581 ret
= recv_data_sessiond(&llm
, sizeof(llm
));
583 /* Ret value is a valid lttng error code. */
587 /* Check error code if OK */
588 if (llm
.ret_code
!= LTTNG_OK
) {
593 size
= llm
.data_size
;
595 /* If client free with size 0 */
603 data
= (void*) malloc(size
);
605 /* Get payload data */
606 ret
= recv_data_sessiond(data
, size
);
613 * Extra protection not to dereference a NULL pointer. If buf is NULL at
614 * this point, an error is returned and data is freed.
617 ret
= -LTTNG_ERR_INVALID
;
626 disconnect_sessiond();
631 * Ask the session daemon a specific command and put the data into buf.
633 * Return size of data (only payload, not header) or a negative error code.
635 static int ask_sessiond(struct lttcomm_session_msg
*lsm
, void **buf
)
637 return ask_sessiond_varlen(lsm
, NULL
, 0, buf
);
641 * Create lttng handle and return pointer.
642 * The returned pointer will be NULL in case of malloc() error.
644 struct lttng_handle
*lttng_create_handle(const char *session_name
,
645 struct lttng_domain
*domain
)
647 struct lttng_handle
*handle
= NULL
;
649 if (domain
== NULL
) {
653 handle
= malloc(sizeof(struct lttng_handle
));
654 if (handle
== NULL
) {
655 PERROR("malloc handle");
659 /* Copy session name */
660 copy_string(handle
->session_name
, session_name
,
661 sizeof(handle
->session_name
));
663 /* Copy lttng domain */
664 copy_lttng_domain(&handle
->domain
, domain
);
671 * Destroy handle by free(3) the pointer.
673 void lttng_destroy_handle(struct lttng_handle
*handle
)
679 * Register an outside consumer.
680 * Returns size of returned session payload data or a negative error code.
682 int lttng_register_consumer(struct lttng_handle
*handle
,
683 const char *socket_path
)
685 struct lttcomm_session_msg lsm
;
687 if (handle
== NULL
|| socket_path
== NULL
) {
688 return -LTTNG_ERR_INVALID
;
691 lsm
.cmd_type
= LTTNG_REGISTER_CONSUMER
;
692 copy_string(lsm
.session
.name
, handle
->session_name
,
693 sizeof(lsm
.session
.name
));
694 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
696 copy_string(lsm
.u
.reg
.path
, socket_path
, sizeof(lsm
.u
.reg
.path
));
698 return ask_sessiond(&lsm
, NULL
);
702 * Start tracing for all traces of the session.
703 * Returns size of returned session payload data or a negative error code.
705 int lttng_start_tracing(const char *session_name
)
707 struct lttcomm_session_msg lsm
;
709 if (session_name
== NULL
) {
710 return -LTTNG_ERR_INVALID
;
713 lsm
.cmd_type
= LTTNG_START_TRACE
;
715 copy_string(lsm
.session
.name
, session_name
, sizeof(lsm
.session
.name
));
717 return ask_sessiond(&lsm
, NULL
);
721 * Stop tracing for all traces of the session.
723 static int _lttng_stop_tracing(const char *session_name
, int wait
)
726 struct lttcomm_session_msg lsm
;
728 if (session_name
== NULL
) {
729 return -LTTNG_ERR_INVALID
;
732 lsm
.cmd_type
= LTTNG_STOP_TRACE
;
734 copy_string(lsm
.session
.name
, session_name
, sizeof(lsm
.session
.name
));
736 ret
= ask_sessiond(&lsm
, NULL
);
737 if (ret
< 0 && ret
!= -LTTNG_ERR_TRACE_ALREADY_STOPPED
) {
745 _MSG("Waiting for data availability");
747 /* Check for data availability */
749 data_ret
= lttng_data_pending(session_name
);
751 /* Return the data available call error. */
757 * Data sleep time before retrying (in usec). Don't sleep if the call
758 * returned value indicates availability.
761 usleep(DEFAULT_DATA_AVAILABILITY_WAIT_TIME
);
764 } while (data_ret
!= 0);
774 * Stop tracing and wait for data availability.
776 int lttng_stop_tracing(const char *session_name
)
778 return _lttng_stop_tracing(session_name
, 1);
782 * Stop tracing but _don't_ wait for data availability.
784 int lttng_stop_tracing_no_wait(const char *session_name
)
786 return _lttng_stop_tracing(session_name
, 0);
790 * Add context to a channel.
792 * If the given channel is NULL, add the contexts to all channels.
793 * The event_name param is ignored.
795 * Returns the size of the returned payload data or a negative error code.
797 int lttng_add_context(struct lttng_handle
*handle
,
798 struct lttng_event_context
*ctx
, const char *event_name
,
799 const char *channel_name
)
801 struct lttcomm_session_msg lsm
;
803 /* Safety check. Both are mandatory */
804 if (handle
== NULL
|| ctx
== NULL
) {
805 return -LTTNG_ERR_INVALID
;
808 memset(&lsm
, 0, sizeof(lsm
));
810 lsm
.cmd_type
= LTTNG_ADD_CONTEXT
;
812 /* Copy channel name */
813 copy_string(lsm
.u
.context
.channel_name
, channel_name
,
814 sizeof(lsm
.u
.context
.channel_name
));
816 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
818 memcpy(&lsm
.u
.context
.ctx
, ctx
, sizeof(struct lttng_event_context
));
820 copy_string(lsm
.session
.name
, handle
->session_name
,
821 sizeof(lsm
.session
.name
));
823 return ask_sessiond(&lsm
, NULL
);
827 * Enable event(s) for a channel.
828 * If no event name is specified, all events are enabled.
829 * If no channel name is specified, the default 'channel0' is used.
830 * Returns size of returned session payload data or a negative error code.
832 int lttng_enable_event(struct lttng_handle
*handle
,
833 struct lttng_event
*ev
, const char *channel_name
)
835 struct lttcomm_session_msg lsm
;
837 if (handle
== NULL
|| ev
== NULL
) {
838 return -LTTNG_ERR_INVALID
;
841 memset(&lsm
, 0, sizeof(lsm
));
843 /* If no channel name, we put the default name */
844 if (channel_name
== NULL
) {
845 copy_string(lsm
.u
.enable
.channel_name
, DEFAULT_CHANNEL_NAME
,
846 sizeof(lsm
.u
.enable
.channel_name
));
848 copy_string(lsm
.u
.enable
.channel_name
, channel_name
,
849 sizeof(lsm
.u
.enable
.channel_name
));
852 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
854 if (ev
->name
[0] != '\0') {
855 lsm
.cmd_type
= LTTNG_ENABLE_EVENT
;
857 lsm
.cmd_type
= LTTNG_ENABLE_ALL_EVENT
;
859 memcpy(&lsm
.u
.enable
.event
, ev
, sizeof(lsm
.u
.enable
.event
));
861 copy_string(lsm
.session
.name
, handle
->session_name
,
862 sizeof(lsm
.session
.name
));
864 return ask_sessiond(&lsm
, NULL
);
868 * Create or enable an event with a filter expression.
870 * Return negative error value on error.
871 * Return size of returned session payload data if OK.
873 int lttng_enable_event_with_filter(struct lttng_handle
*handle
,
874 struct lttng_event
*event
, const char *channel_name
,
875 const char *filter_expression
)
877 struct lttcomm_session_msg lsm
;
878 struct filter_parser_ctx
*ctx
;
882 if (!filter_expression
) {
884 * Fall back to normal event enabling if no filter
887 return lttng_enable_event(handle
, event
, channel_name
);
891 * Empty filter string will always be rejected by the parser
892 * anyway, so treat this corner-case early to eliminate
893 * lttng_fmemopen error for 0-byte allocation.
895 if (handle
== NULL
|| filter_expression
[0] == '\0') {
896 return -LTTNG_ERR_INVALID
;
900 * casting const to non-const, as the underlying function will
901 * use it in read-only mode.
903 fmem
= lttng_fmemopen((void *) filter_expression
,
904 strlen(filter_expression
), "r");
906 fprintf(stderr
, "Error opening memory as stream\n");
907 return -LTTNG_ERR_FILTER_NOMEM
;
909 ctx
= filter_parser_ctx_alloc(fmem
);
911 fprintf(stderr
, "Error allocating parser\n");
912 ret
= -LTTNG_ERR_FILTER_NOMEM
;
915 ret
= filter_parser_ctx_append_ast(ctx
);
917 fprintf(stderr
, "Parse error\n");
918 ret
= -LTTNG_ERR_FILTER_INVAL
;
921 ret
= filter_visitor_set_parent(ctx
);
923 fprintf(stderr
, "Set parent error\n");
924 ret
= -LTTNG_ERR_FILTER_INVAL
;
928 ret
= filter_visitor_print_xml(ctx
, stdout
, 0);
931 fprintf(stderr
, "XML print error\n");
932 ret
= -LTTNG_ERR_FILTER_INVAL
;
937 dbg_printf("Generating IR... ");
939 ret
= filter_visitor_ir_generate(ctx
);
941 fprintf(stderr
, "Generate IR error\n");
942 ret
= -LTTNG_ERR_FILTER_INVAL
;
945 dbg_printf("done\n");
947 dbg_printf("Validating IR... ");
949 ret
= filter_visitor_ir_check_binary_op_nesting(ctx
);
951 ret
= -LTTNG_ERR_FILTER_INVAL
;
954 dbg_printf("done\n");
956 dbg_printf("Generating bytecode... ");
958 ret
= filter_visitor_bytecode_generate(ctx
);
960 fprintf(stderr
, "Generate bytecode error\n");
961 ret
= -LTTNG_ERR_FILTER_INVAL
;
964 dbg_printf("done\n");
965 dbg_printf("Size of bytecode generated: %u bytes.\n",
966 bytecode_get_len(&ctx
->bytecode
->b
));
968 memset(&lsm
, 0, sizeof(lsm
));
970 lsm
.cmd_type
= LTTNG_ENABLE_EVENT_WITH_FILTER
;
972 /* Copy channel name */
973 copy_string(lsm
.u
.enable
.channel_name
, channel_name
,
974 sizeof(lsm
.u
.enable
.channel_name
));
975 /* Copy event name */
977 memcpy(&lsm
.u
.enable
.event
, event
, sizeof(lsm
.u
.enable
.event
));
980 lsm
.u
.enable
.bytecode_len
= sizeof(ctx
->bytecode
->b
)
981 + bytecode_get_len(&ctx
->bytecode
->b
);
983 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
985 copy_string(lsm
.session
.name
, handle
->session_name
,
986 sizeof(lsm
.session
.name
));
988 ret
= ask_sessiond_varlen(&lsm
, &ctx
->bytecode
->b
,
989 lsm
.u
.enable
.bytecode_len
, NULL
);
991 filter_bytecode_free(ctx
);
993 filter_parser_ctx_free(ctx
);
994 if (fclose(fmem
) != 0) {
1000 filter_bytecode_free(ctx
);
1001 filter_ir_free(ctx
);
1002 filter_parser_ctx_free(ctx
);
1004 if (fclose(fmem
) != 0) {
1011 * Disable event(s) of a channel and domain.
1012 * If no event name is specified, all events are disabled.
1013 * If no channel name is specified, the default 'channel0' is used.
1014 * Returns size of returned session payload data or a negative error code.
1016 int lttng_disable_event(struct lttng_handle
*handle
, const char *name
,
1017 const char *channel_name
)
1019 struct lttcomm_session_msg lsm
;
1021 if (handle
== NULL
) {
1022 return -LTTNG_ERR_INVALID
;
1025 memset(&lsm
, 0, sizeof(lsm
));
1028 copy_string(lsm
.u
.disable
.channel_name
, channel_name
,
1029 sizeof(lsm
.u
.disable
.channel_name
));
1031 copy_string(lsm
.u
.disable
.channel_name
, DEFAULT_CHANNEL_NAME
,
1032 sizeof(lsm
.u
.disable
.channel_name
));
1035 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
1038 copy_string(lsm
.u
.disable
.name
, name
, sizeof(lsm
.u
.disable
.name
));
1039 lsm
.cmd_type
= LTTNG_DISABLE_EVENT
;
1041 lsm
.cmd_type
= LTTNG_DISABLE_ALL_EVENT
;
1044 copy_string(lsm
.session
.name
, handle
->session_name
,
1045 sizeof(lsm
.session
.name
));
1047 return ask_sessiond(&lsm
, NULL
);
1051 * Enable channel per domain
1052 * Returns size of returned session payload data or a negative error code.
1054 int lttng_enable_channel(struct lttng_handle
*handle
,
1055 struct lttng_channel
*chan
)
1057 struct lttcomm_session_msg lsm
;
1060 * NULL arguments are forbidden. No default values.
1062 if (handle
== NULL
|| chan
== NULL
) {
1063 return -LTTNG_ERR_INVALID
;
1066 memset(&lsm
, 0, sizeof(lsm
));
1068 memcpy(&lsm
.u
.channel
.chan
, chan
, sizeof(lsm
.u
.channel
.chan
));
1070 lsm
.cmd_type
= LTTNG_ENABLE_CHANNEL
;
1072 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
1074 copy_string(lsm
.session
.name
, handle
->session_name
,
1075 sizeof(lsm
.session
.name
));
1077 return ask_sessiond(&lsm
, NULL
);
1081 * All tracing will be stopped for registered events of the channel.
1082 * Returns size of returned session payload data or a negative error code.
1084 int lttng_disable_channel(struct lttng_handle
*handle
, const char *name
)
1086 struct lttcomm_session_msg lsm
;
1088 /* Safety check. Both are mandatory */
1089 if (handle
== NULL
|| name
== NULL
) {
1090 return -LTTNG_ERR_INVALID
;
1093 memset(&lsm
, 0, sizeof(lsm
));
1095 lsm
.cmd_type
= LTTNG_DISABLE_CHANNEL
;
1097 copy_string(lsm
.u
.disable
.channel_name
, name
,
1098 sizeof(lsm
.u
.disable
.channel_name
));
1100 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
1102 copy_string(lsm
.session
.name
, handle
->session_name
,
1103 sizeof(lsm
.session
.name
));
1105 return ask_sessiond(&lsm
, NULL
);
1109 * Lists all available tracepoints of domain.
1110 * Sets the contents of the events array.
1111 * Returns the number of lttng_event entries in events;
1112 * on error, returns a negative value.
1114 int lttng_list_tracepoints(struct lttng_handle
*handle
,
1115 struct lttng_event
**events
)
1118 struct lttcomm_session_msg lsm
;
1120 if (handle
== NULL
) {
1121 return -LTTNG_ERR_INVALID
;
1124 lsm
.cmd_type
= LTTNG_LIST_TRACEPOINTS
;
1125 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
1127 ret
= ask_sessiond(&lsm
, (void **) events
);
1132 return ret
/ sizeof(struct lttng_event
);
1136 * Lists all available tracepoint fields of domain.
1137 * Sets the contents of the event field array.
1138 * Returns the number of lttng_event_field entries in events;
1139 * on error, returns a negative value.
1141 int lttng_list_tracepoint_fields(struct lttng_handle
*handle
,
1142 struct lttng_event_field
**fields
)
1145 struct lttcomm_session_msg lsm
;
1147 if (handle
== NULL
) {
1148 return -LTTNG_ERR_INVALID
;
1151 lsm
.cmd_type
= LTTNG_LIST_TRACEPOINT_FIELDS
;
1152 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
1154 ret
= ask_sessiond(&lsm
, (void **) fields
);
1159 return ret
/ sizeof(struct lttng_event_field
);
1163 * Returns a human readable string describing
1164 * the error code (a negative value).
1166 const char *lttng_strerror(int code
)
1168 return error_get_str(code
);
1172 * Create a brand new session using name and url for destination.
1174 * Returns LTTNG_OK on success or a negative error code.
1176 int lttng_create_session(const char *name
, const char *url
)
1180 struct lttcomm_session_msg lsm
;
1181 struct lttng_uri
*uris
= NULL
;
1184 return -LTTNG_ERR_INVALID
;
1187 memset(&lsm
, 0, sizeof(lsm
));
1189 lsm
.cmd_type
= LTTNG_CREATE_SESSION
;
1190 copy_string(lsm
.session
.name
, name
, sizeof(lsm
.session
.name
));
1192 /* There should never be a data URL */
1193 size
= parse_str_urls_to_uri(url
, NULL
, &uris
);
1195 return -LTTNG_ERR_INVALID
;
1198 lsm
.u
.uri
.size
= size
;
1200 ret
= ask_sessiond_varlen(&lsm
, uris
, sizeof(struct lttng_uri
) * size
,
1208 * Destroy session using name.
1209 * Returns size of returned session payload data or a negative error code.
1211 int lttng_destroy_session(const char *session_name
)
1213 struct lttcomm_session_msg lsm
;
1215 if (session_name
== NULL
) {
1216 return -LTTNG_ERR_INVALID
;
1219 lsm
.cmd_type
= LTTNG_DESTROY_SESSION
;
1221 copy_string(lsm
.session
.name
, session_name
, sizeof(lsm
.session
.name
));
1223 return ask_sessiond(&lsm
, NULL
);
1227 * Ask the session daemon for all available sessions.
1228 * Sets the contents of the sessions array.
1229 * Returns the number of lttng_session entries in sessions;
1230 * on error, returns a negative value.
1232 int lttng_list_sessions(struct lttng_session
**sessions
)
1235 struct lttcomm_session_msg lsm
;
1237 lsm
.cmd_type
= LTTNG_LIST_SESSIONS
;
1238 ret
= ask_sessiond(&lsm
, (void**) sessions
);
1243 return ret
/ sizeof(struct lttng_session
);
1247 * Ask the session daemon for all available domains of a session.
1248 * Sets the contents of the domains array.
1249 * Returns the number of lttng_domain entries in domains;
1250 * on error, returns a negative value.
1252 int lttng_list_domains(const char *session_name
,
1253 struct lttng_domain
**domains
)
1256 struct lttcomm_session_msg lsm
;
1258 if (session_name
== NULL
) {
1259 return -LTTNG_ERR_INVALID
;
1262 lsm
.cmd_type
= LTTNG_LIST_DOMAINS
;
1264 copy_string(lsm
.session
.name
, session_name
, sizeof(lsm
.session
.name
));
1266 ret
= ask_sessiond(&lsm
, (void**) domains
);
1271 return ret
/ sizeof(struct lttng_domain
);
1275 * Ask the session daemon for all available channels of a session.
1276 * Sets the contents of the channels array.
1277 * Returns the number of lttng_channel entries in channels;
1278 * on error, returns a negative value.
1280 int lttng_list_channels(struct lttng_handle
*handle
,
1281 struct lttng_channel
**channels
)
1284 struct lttcomm_session_msg lsm
;
1286 if (handle
== NULL
) {
1287 return -LTTNG_ERR_INVALID
;
1290 lsm
.cmd_type
= LTTNG_LIST_CHANNELS
;
1291 copy_string(lsm
.session
.name
, handle
->session_name
,
1292 sizeof(lsm
.session
.name
));
1294 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
1296 ret
= ask_sessiond(&lsm
, (void**) channels
);
1301 return ret
/ sizeof(struct lttng_channel
);
1305 * Ask the session daemon for all available events of a session channel.
1306 * Sets the contents of the events array.
1307 * Returns the number of lttng_event entries in events;
1308 * on error, returns a negative value.
1310 int lttng_list_events(struct lttng_handle
*handle
,
1311 const char *channel_name
, struct lttng_event
**events
)
1314 struct lttcomm_session_msg lsm
;
1316 /* Safety check. An handle and channel name are mandatory */
1317 if (handle
== NULL
|| channel_name
== NULL
) {
1318 return -LTTNG_ERR_INVALID
;
1321 lsm
.cmd_type
= LTTNG_LIST_EVENTS
;
1322 copy_string(lsm
.session
.name
, handle
->session_name
,
1323 sizeof(lsm
.session
.name
));
1324 copy_string(lsm
.u
.list
.channel_name
, channel_name
,
1325 sizeof(lsm
.u
.list
.channel_name
));
1327 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
1329 ret
= ask_sessiond(&lsm
, (void**) events
);
1334 return ret
/ sizeof(struct lttng_event
);
1338 * Sets the tracing_group variable with name.
1339 * This function allocates memory pointed to by tracing_group.
1340 * On success, returns 0, on error, returns -1 (null name) or -ENOMEM.
1342 int lttng_set_tracing_group(const char *name
)
1345 return -LTTNG_ERR_INVALID
;
1348 if (asprintf(&tracing_group
, "%s", name
) < 0) {
1349 return -LTTNG_ERR_FATAL
;
1356 * Returns size of returned session payload data or a negative error code.
1358 int lttng_calibrate(struct lttng_handle
*handle
,
1359 struct lttng_calibrate
*calibrate
)
1361 struct lttcomm_session_msg lsm
;
1363 /* Safety check. NULL pointer are forbidden */
1364 if (handle
== NULL
|| calibrate
== NULL
) {
1365 return -LTTNG_ERR_INVALID
;
1368 lsm
.cmd_type
= LTTNG_CALIBRATE
;
1369 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
1371 memcpy(&lsm
.u
.calibrate
, calibrate
, sizeof(lsm
.u
.calibrate
));
1373 return ask_sessiond(&lsm
, NULL
);
1377 * Set default channel attributes.
1378 * If either or both of the arguments are null, attr content is zeroe'd.
1380 void lttng_channel_set_default_attr(struct lttng_domain
*domain
,
1381 struct lttng_channel_attr
*attr
)
1384 if (attr
== NULL
|| domain
== NULL
) {
1388 memset(attr
, 0, sizeof(struct lttng_channel_attr
));
1390 /* Same for all domains. */
1391 attr
->overwrite
= DEFAULT_CHANNEL_OVERWRITE
;
1392 attr
->tracefile_size
= DEFAULT_CHANNEL_TRACEFILE_SIZE
;
1393 attr
->tracefile_count
= DEFAULT_CHANNEL_TRACEFILE_COUNT
;
1395 switch (domain
->type
) {
1396 case LTTNG_DOMAIN_KERNEL
:
1397 attr
->switch_timer_interval
= DEFAULT_KERNEL_CHANNEL_SWITCH_TIMER
;
1398 attr
->read_timer_interval
= DEFAULT_KERNEL_CHANNEL_READ_TIMER
;
1399 attr
->subbuf_size
= default_get_kernel_channel_subbuf_size();
1400 attr
->num_subbuf
= DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM
;
1401 attr
->output
= DEFAULT_KERNEL_CHANNEL_OUTPUT
;
1403 case LTTNG_DOMAIN_UST
:
1404 switch (domain
->buf_type
) {
1405 case LTTNG_BUFFER_PER_UID
:
1406 attr
->subbuf_size
= default_get_ust_uid_channel_subbuf_size();
1407 attr
->num_subbuf
= DEFAULT_UST_UID_CHANNEL_SUBBUF_NUM
;
1408 attr
->output
= DEFAULT_UST_UID_CHANNEL_OUTPUT
;
1409 attr
->switch_timer_interval
= DEFAULT_UST_UID_CHANNEL_SWITCH_TIMER
;
1410 attr
->read_timer_interval
= DEFAULT_UST_UID_CHANNEL_READ_TIMER
;
1412 case LTTNG_BUFFER_PER_PID
:
1414 attr
->subbuf_size
= default_get_ust_pid_channel_subbuf_size();
1415 attr
->num_subbuf
= DEFAULT_UST_PID_CHANNEL_SUBBUF_NUM
;
1416 attr
->output
= DEFAULT_UST_PID_CHANNEL_OUTPUT
;
1417 attr
->switch_timer_interval
= DEFAULT_UST_PID_CHANNEL_SWITCH_TIMER
;
1418 attr
->read_timer_interval
= DEFAULT_UST_PID_CHANNEL_READ_TIMER
;
1422 /* Default behavior: leave set to 0. */
1428 * Check if session daemon is alive.
1430 * Return 1 if alive or 0 if not.
1431 * On error returns a negative value.
1433 int lttng_session_daemon_alive(void)
1437 ret
= set_session_daemon_path();
1443 if (*sessiond_sock_path
== '\0') {
1445 * No socket path set. Weird error which means the constructor was not
1451 ret
= try_connect_sessiond(sessiond_sock_path
);
1462 * Set URL for a consumer for a session and domain.
1464 * Return 0 on success, else a negative value.
1466 int lttng_set_consumer_url(struct lttng_handle
*handle
,
1467 const char *control_url
, const char *data_url
)
1471 struct lttcomm_session_msg lsm
;
1472 struct lttng_uri
*uris
= NULL
;
1474 if (handle
== NULL
|| (control_url
== NULL
&& data_url
== NULL
)) {
1475 return -LTTNG_ERR_INVALID
;
1478 memset(&lsm
, 0, sizeof(lsm
));
1480 lsm
.cmd_type
= LTTNG_SET_CONSUMER_URI
;
1482 copy_string(lsm
.session
.name
, handle
->session_name
,
1483 sizeof(lsm
.session
.name
));
1484 copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
1486 size
= parse_str_urls_to_uri(control_url
, data_url
, &uris
);
1488 return -LTTNG_ERR_INVALID
;
1491 lsm
.u
.uri
.size
= size
;
1493 ret
= ask_sessiond_varlen(&lsm
, uris
, sizeof(struct lttng_uri
) * size
,
1503 int lttng_enable_consumer(struct lttng_handle
*handle
)
1511 int lttng_disable_consumer(struct lttng_handle
*handle
)
1517 * Set health socket path by putting it in the global health_sock_path
1520 * Returns 0 on success or assert(0) on ENOMEM.
1522 static int set_health_socket_path(void)
1524 int in_tgroup
= 0; /* In tracing group */
1531 /* Are we in the tracing group ? */
1532 in_tgroup
= check_tracing_group(tracing_group
);
1535 if ((uid
== 0) || in_tgroup
) {
1536 copy_string(health_sock_path
, DEFAULT_GLOBAL_HEALTH_UNIX_SOCK
,
1537 sizeof(health_sock_path
));
1544 * With GNU C < 2.1, snprintf returns -1 if the target buffer is too small;
1545 * With GNU C >= 2.1, snprintf returns the required size (excluding closing null)
1547 home
= utils_get_home_dir();
1549 /* Fallback in /tmp .. */
1553 ret
= snprintf(health_sock_path
, sizeof(health_sock_path
),
1554 DEFAULT_HOME_HEALTH_UNIX_SOCK
, home
);
1555 if ((ret
< 0) || (ret
>= sizeof(health_sock_path
))) {
1556 /* ENOMEM at this point... just kill the control lib. */
1565 * Check session daemon health for a specific health component.
1567 * Return 0 if health is OK or else 1 if BAD.
1569 * Any other negative value is a lttng error code which can be translated with
1572 int lttng_health_check(enum lttng_health_component c
)
1575 struct lttcomm_health_msg msg
;
1576 struct lttcomm_health_data reply
;
1578 /* Connect to the sesssion daemon */
1579 sock
= lttcomm_connect_unix_sock(health_sock_path
);
1581 ret
= -LTTNG_ERR_NO_SESSIOND
;
1585 msg
.cmd
= LTTNG_HEALTH_CHECK
;
1588 ret
= lttcomm_send_unix_sock(sock
, (void *)&msg
, sizeof(msg
));
1590 ret
= -LTTNG_ERR_FATAL
;
1594 ret
= lttcomm_recv_unix_sock(sock
, (void *)&reply
, sizeof(reply
));
1596 ret
= -LTTNG_ERR_FATAL
;
1600 ret
= reply
.ret_code
;
1606 closeret
= close(sock
);
1615 * This is an extension of create session that is ONLY and SHOULD only be used
1616 * by the lttng command line program. It exists to avoid using URI parsing in
1619 * We need the date and time for the trace path subdirectory for the case where
1620 * the user does NOT define one using either -o or -U. Using the normal
1621 * lttng_create_session API call, we have no clue on the session daemon side if
1622 * the URL was generated automatically by the client or define by the user.
1624 * So this function "wrapper" is hidden from the public API, takes the datetime
1625 * string and appends it if necessary to the URI subdirectory before sending it
1626 * to the session daemon.
1628 * With this extra function, the lttng_create_session call behavior is not
1629 * changed and the timestamp is appended to the URI on the session daemon side
1632 int _lttng_create_session_ext(const char *name
, const char *url
,
1633 const char *datetime
)
1637 struct lttcomm_session_msg lsm
;
1638 struct lttng_uri
*uris
= NULL
;
1640 if (name
== NULL
|| datetime
== NULL
|| url
== NULL
) {
1641 return -LTTNG_ERR_INVALID
;
1644 memset(&lsm
, 0, sizeof(lsm
));
1646 lsm
.cmd_type
= LTTNG_CREATE_SESSION
;
1647 copy_string(lsm
.session
.name
, name
, sizeof(lsm
.session
.name
));
1649 /* There should never be a data URL */
1650 size
= parse_str_urls_to_uri(url
, NULL
, &uris
);
1652 ret
= -LTTNG_ERR_INVALID
;
1656 lsm
.u
.uri
.size
= size
;
1658 if (size
> 0 && uris
[0].dtype
!= LTTNG_DST_PATH
&& strlen(uris
[0].subdir
) == 0) {
1659 /* Don't append datetime if the name was automatically created. */
1660 if (strncmp(name
, DEFAULT_SESSION_NAME
"-",
1661 strlen(DEFAULT_SESSION_NAME
) + 1)) {
1662 ret
= snprintf(uris
[0].subdir
, sizeof(uris
[0].subdir
), "%s-%s",
1665 ret
= snprintf(uris
[0].subdir
, sizeof(uris
[0].subdir
), "%s", name
);
1668 PERROR("snprintf uri subdir");
1669 ret
= -LTTNG_ERR_FATAL
;
1674 ret
= ask_sessiond_varlen(&lsm
, uris
, sizeof(struct lttng_uri
) * size
,
1683 * For a given session name, this call checks if the data is ready to be read
1684 * or is still being extracted by the consumer(s) hence not ready to be used by
1687 int lttng_data_pending(const char *session_name
)
1690 struct lttcomm_session_msg lsm
;
1692 if (session_name
== NULL
) {
1693 return -LTTNG_ERR_INVALID
;
1696 lsm
.cmd_type
= LTTNG_DATA_PENDING
;
1698 copy_string(lsm
.session
.name
, session_name
, sizeof(lsm
.session
.name
));
1700 ret
= ask_sessiond(&lsm
, NULL
);
1703 * The ask_sessiond function negate the return code if it's not LTTNG_OK so
1704 * getting -1 means that the reply ret_code was 1 thus meaning that the
1705 * data is available. Yes it is hackish but for now this is the only way.
1717 static void __attribute__((constructor
)) init()
1719 /* Set default session group */
1720 lttng_set_tracing_group(DEFAULT_TRACING_GROUP
);
1721 /* Set socket for health check */
1722 (void) set_health_socket_path();
1728 static void __attribute__((destructor
)) lttng_ctl_exit()
1730 free(tracing_group
);