src/common/notification.c

   1 /*
   2  * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * This library is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU Lesser General Public License, version 2.1 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This library is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
  11  * for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public License
  14  * along with this library; if not, write to the Free Software Foundation,
  15  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  16  */
  17
  18 #include <lttng/notification/notification-internal.h>
  19 #include <lttng/condition/condition-internal.h>
  20 #include <lttng/condition/evaluation-internal.h>
  21 #include <lttng/condition/condition.h>
  22 #include <lttng/condition/evaluation.h>
  23 #include <assert.h>
  24
  25 LTTNG_HIDDEN
  26 struct lttng_notification *lttng_notification_create(
  27                 struct lttng_condition *condition,
  28                 struct lttng_evaluation *evaluation)
  29 {
  30         struct lttng_notification *notification = NULL;
  31
  32         if (!condition || !evaluation) {
  33                 goto end;
  34         }
  35
  36         notification = zmalloc(sizeof(struct lttng_notification));
  37         if (!notification) {
  38                 goto end;
  39         }
  40
  41         notification->condition = condition;
  42         notification->evaluation = evaluation;
  43         notification->owns_elements = false;
  44 end:
  45         return notification;
  46 }
  47
  48 LTTNG_HIDDEN
  49 ssize_t lttng_notification_serialize(struct lttng_notification *notification,
  50                 char *buf)
  51 {
  52         ssize_t ret, condition_size, evaluation_size, offset = 0;
  53         struct lttng_notification_comm notification_comm = { 0 };
  54
  55         if (!notification) {
  56                 ret = -1;
  57                 goto end;
  58         }
  59
  60         offset += sizeof(notification_comm);
  61         condition_size = lttng_condition_serialize(notification->condition,
  62                         buf ? (buf + offset) : NULL);
  63         if (condition_size < 0) {
  64                 ret = condition_size;
  65                 goto end;
  66         }
  67         offset += condition_size;
  68
  69         evaluation_size = lttng_evaluation_serialize(notification->evaluation,
  70                         buf ? (buf + offset) : NULL);
  71         if (evaluation_size < 0) {
  72                 ret = evaluation_size;
  73                 goto end;
  74         }
  75         offset += evaluation_size;
  76
  77         if (buf) {
  78                 notification_comm.length =
  79                                 (uint32_t) (condition_size + evaluation_size);
  80                 memcpy(buf, &notification_comm, sizeof(notification_comm));
  81         }
  82         ret = offset;
  83 end:
  84         return ret;
  85
  86 }
  87
  88 LTTNG_HIDDEN
  89 ssize_t lttng_notification_create_from_buffer(
  90                 const struct lttng_buffer_view *src_view,
  91                 struct lttng_notification **notification)
  92 {
  93         ssize_t ret, notification_size = 0, condition_size, evaluation_size;
  94         const struct lttng_notification_comm *notification_comm;
  95         struct lttng_condition *condition;
  96         struct lttng_evaluation *evaluation;
  97         struct lttng_buffer_view condition_view;
  98         struct lttng_buffer_view evaluation_view;
  99
 100         if (!src_view || !notification) {
 101                 ret = -1;
 102                 goto end;
 103         }
 104
 105         notification_comm =
 106                         (const struct lttng_notification_comm *) src_view->data;
 107         notification_size += sizeof(*notification_comm);
 108
 109         /* struct lttng_condition */
 110         condition_view = lttng_buffer_view_from_view(src_view,
 111                         sizeof(*notification_comm), -1);
 112         condition_size = lttng_condition_create_from_buffer(&condition_view,
 113                         &condition);
 114         if (condition_size < 0) {
 115                 ret = condition_size;
 116                 goto end;
 117         }
 118         notification_size += condition_size;
 119
 120         /* struct lttng_evaluation */
 121         evaluation_view = lttng_buffer_view_from_view(&condition_view,
 122                         condition_size, -1);
 123         evaluation_size = lttng_evaluation_create_from_buffer(&evaluation_view,
 124                         &evaluation);
 125         if (evaluation_size < 0) {
 126                 ret = evaluation_size;
 127                 goto end;
 128         }
 129         notification_size += evaluation_size;
 130
 131         /* Unexpected size of inner-elements; the buffer is corrupted. */
 132         if ((ssize_t) notification_comm->length !=
 133                         condition_size + evaluation_size) {
 134                 ret = -1;
 135                 goto error;
 136         }
 137
 138         *notification = lttng_notification_create(condition, evaluation);
 139         if (!*notification) {
 140                 ret = -1;
 141                 goto error;
 142         }
 143         ret = notification_size;
 144         (*notification)->owns_elements = true;
 145 end:
 146         return ret;
 147 error:
 148         lttng_condition_destroy(condition);
 149         lttng_evaluation_destroy(evaluation);
 150         return ret;
 151 }
 152
 153 void lttng_notification_destroy(struct lttng_notification *notification)
 154 {
 155         if (!notification) {
 156                 return;
 157         }
 158
 159         if (notification->owns_elements) {
 160                 lttng_condition_destroy(notification->condition);
 161                 lttng_evaluation_destroy(notification->evaluation);
 162         }
 163         free(notification);
 164 }
 165
 166 const struct lttng_condition *lttng_notification_get_condition(
 167                 struct lttng_notification *notification)
 168 {
 169         return notification ? notification->condition : NULL;
 170 }
 171
 172 const struct lttng_evaluation *lttng_notification_get_evaluation(
 173                 struct lttng_notification *notification)
 174 {
 175         return notification ? notification->evaluation : NULL;
 176 }