src/lib/lttng-ctl/event.c

   1 /*
   2  * event.c
   3  *
   4  * Linux Trace Toolkit Control Library
   5  *
   6  * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   7  *
   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.
  11  *
  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.
  16  *
  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
  20  */
  21
  22 #define _LGPL_SOURCE
  23 #include <assert.h>
  24 #include <stddef.h>
  25
  26 #include <common/error.h>
  27 #include <common/sessiond-comm/sessiond-comm.h>
  28 #include <lttng/event-internal.h>
  29 #include <lttng/event.h>
  30 #include <lttng/lttng-error.h>
  31 #include <lttng/userspace-probe-internal.h>
  32
  33 struct lttng_event *lttng_event_create(void)
  34 {
  35         struct lttng_event *event;
  36         struct lttng_event_extended *event_extended;
  37
  38         event = zmalloc(sizeof(*event));
  39         if (!event) {
  40                 PERROR("Error allocating event structure");
  41                 goto end;
  42         }
  43
  44         event_extended = zmalloc(sizeof(*event_extended));
  45         if (!event_extended) {
  46                 PERROR("Error allocating event extended structure");
  47                 goto error;
  48         }
  49         event->extended.ptr = event_extended;
  50 end:
  51         return event;
  52 error:
  53         free(event);
  54         goto end;
  55 }
  56
  57 void lttng_event_destroy(struct lttng_event *event)
  58 {
  59         struct lttng_event_extended *event_extended;
  60
  61         if (!event) {
  62                 return;
  63         }
  64
  65         event_extended = (struct lttng_event_extended *) event->extended.ptr;
  66
  67         if (event_extended) {
  68                 if (event_extended->probe_location) {
  69                         lttng_userspace_probe_location_destroy(
  70                                 event_extended->probe_location);
  71                 }
  72                 free(event_extended);
  73         }
  74         free(event);
  75 }
  76
  77 int lttng_event_get_filter_expression(struct lttng_event *event,
  78         const char **filter_expression)
  79 {
  80         int ret = 0;
  81         struct lttcomm_event_extended_header *ext_header;
  82
  83         if (!event || !filter_expression) {
  84                 ret = -LTTNG_ERR_INVALID;
  85                 goto end;
  86         }
  87
  88         ext_header = event->extended.ptr;
  89
  90         if (!ext_header) {
  91                 /*
  92                  * This can happen since the lttng_event structure is
  93                  * used for other tasks where this pointer is never set.
  94                  */
  95                 *filter_expression = NULL;
  96                 goto end;
  97         }
  98
  99         if (ext_header->filter_len) {
 100                 *filter_expression = ((const char *) (ext_header)) +
 101                                 sizeof(*ext_header);
 102         } else {
 103                 *filter_expression = NULL;
 104         }
 105
 106 end:
 107         return ret;
 108 }
 109
 110 int lttng_event_get_exclusion_name_count(struct lttng_event *event)
 111 {
 112         int ret;
 113         struct lttcomm_event_extended_header *ext_header;
 114
 115         if (!event) {
 116                 ret = -LTTNG_ERR_INVALID;
 117                 goto end;
 118         }
 119
 120         ext_header = event->extended.ptr;
 121         if (!ext_header) {
 122                 /*
 123                  * This can happen since the lttng_event structure is
 124                  * used for other tasks where this pointer is never set.
 125                  */
 126                 ret = 0;
 127                 goto end;
 128         }
 129
 130         if (ext_header->nb_exclusions > INT_MAX) {
 131                 ret = -LTTNG_ERR_OVERFLOW;
 132                 goto end;
 133         }
 134         ret = (int) ext_header->nb_exclusions;
 135 end:
 136         return ret;
 137 }
 138
 139 int lttng_event_get_exclusion_name(struct lttng_event *event,
 140                 size_t index, const char **exclusion_name)
 141 {
 142         int ret = 0;
 143         struct lttcomm_event_extended_header *ext_header;
 144         void *at;
 145
 146         if (!event || !exclusion_name) {
 147                 ret = -LTTNG_ERR_INVALID;
 148                 goto end;
 149         }
 150
 151         ext_header = event->extended.ptr;
 152         if (!ext_header) {
 153                 ret = -LTTNG_ERR_INVALID;
 154                 goto end;
 155         }
 156
 157         if (index >= ext_header->nb_exclusions) {
 158                 ret = -LTTNG_ERR_INVALID;
 159                 goto end;
 160         }
 161
 162         at = (void *) ext_header + sizeof(*ext_header);
 163         at += ext_header->filter_len;
 164         at += index * LTTNG_SYMBOL_NAME_LEN;
 165         *exclusion_name = at;
 166
 167 end:
 168         return ret;
 169 }
 170
 171 struct lttng_userspace_probe_location *
 172 lttng_event_get_userspace_probe_location(struct lttng_event *event)
 173 {
 174         struct lttng_userspace_probe_location *probe_location = NULL;
 175         struct lttng_event_extended *event_extended;
 176
 177         if (!event) {
 178                 goto end;
 179         }
 180
 181         event_extended = (struct lttng_event_extended *) event->extended.ptr;
 182         if (!event_extended) {
 183                 goto end;
 184         }
 185         probe_location = event_extended->probe_location;
 186 end:
 187         return probe_location;
 188 }
 189
 190 int lttng_event_set_userspace_probe_location(struct lttng_event *event,
 191                 struct lttng_userspace_probe_location *probe_location)
 192 {
 193         int ret = 0;
 194         struct lttng_event_extended *event_extended;
 195
 196         if (!event || !probe_location) {
 197                 ret = -LTTNG_ERR_INVALID;
 198                 goto end;
 199         }
 200
 201         event_extended = (struct lttng_event_extended *) event->extended.ptr;
 202         assert(event_extended);
 203         if (event_extended->probe_location) {
 204                 lttng_userspace_probe_location_destroy(
 205                         event_extended->probe_location);
 206         }
 207         event_extended->probe_location = probe_location;
 208 end:
 209         return ret;
 210 }