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 int lttng_notification_serialize(struct lttng_notification *notification,
  50                 struct lttng_dynamic_buffer *buf)
  51 {
  52         int ret;
  53         size_t header_offset, size_before_payload;
  54         struct lttng_notification_comm notification_comm = { 0 };
  55         struct lttng_notification_comm *header;
  56
  57         header_offset = buf->size;
  58         ret = lttng_dynamic_buffer_append(buf, &notification_comm,
  59                         sizeof(notification_comm));
  60
  61         size_before_payload = buf->size;
  62         ret = lttng_condition_serialize(notification->condition,
  63                         buf);
  64         if (ret) {
  65                 goto end;
  66         }
  67
  68         ret = lttng_evaluation_serialize(notification->evaluation, buf);
  69         if (ret) {
  70                 goto end;
  71         }
  72
  73         /* Update payload size. */
  74         header = (struct lttng_notification_comm *) ((char *) buf->data + header_offset);
  75         header->length = (uint32_t) (buf->size - size_before_payload);
  76 end:
  77         return ret;
  78
  79 }
  80
  81 LTTNG_HIDDEN
  82 ssize_t lttng_notification_create_from_buffer(
  83                 const struct lttng_buffer_view *src_view,
  84                 struct lttng_notification **notification)
  85 {
  86         ssize_t ret, notification_size = 0, condition_size, evaluation_size;
  87         const struct lttng_notification_comm *notification_comm;
  88         struct lttng_condition *condition;
  89         struct lttng_evaluation *evaluation;
  90         struct lttng_buffer_view condition_view;
  91         struct lttng_buffer_view evaluation_view;
  92
  93         if (!src_view || !notification) {
  94                 ret = -1;
  95                 goto end;
  96         }
  97
  98         notification_comm =
  99                         (const struct lttng_notification_comm *) src_view->data;
 100         notification_size += sizeof(*notification_comm);
 101
 102         /* struct lttng_condition */
 103         condition_view = lttng_buffer_view_from_view(src_view,
 104                         sizeof(*notification_comm), -1);
 105         condition_size = lttng_condition_create_from_buffer(&condition_view,
 106                         &condition);
 107         if (condition_size < 0) {
 108                 ret = condition_size;
 109                 goto end;
 110         }
 111         notification_size += condition_size;
 112
 113         /* struct lttng_evaluation */
 114         evaluation_view = lttng_buffer_view_from_view(&condition_view,
 115                         condition_size, -1);
 116         evaluation_size = lttng_evaluation_create_from_buffer(&evaluation_view,
 117                         &evaluation);
 118         if (evaluation_size < 0) {
 119                 ret = evaluation_size;
 120                 goto end;
 121         }
 122         notification_size += evaluation_size;
 123
 124         /* Unexpected size of inner-elements; the buffer is corrupted. */
 125         if ((ssize_t) notification_comm->length !=
 126                         condition_size + evaluation_size) {
 127                 ret = -1;
 128                 goto error;
 129         }
 130
 131         *notification = lttng_notification_create(condition, evaluation);
 132         if (!*notification) {
 133                 ret = -1;
 134                 goto error;
 135         }
 136         ret = notification_size;
 137         (*notification)->owns_elements = true;
 138 end:
 139         return ret;
 140 error:
 141         lttng_condition_destroy(condition);
 142         lttng_evaluation_destroy(evaluation);
 143         return ret;
 144 }
 145
 146 void lttng_notification_destroy(struct lttng_notification *notification)
 147 {
 148         if (!notification) {
 149                 return;
 150         }
 151
 152         if (notification->owns_elements) {
 153                 lttng_condition_destroy(notification->condition);
 154                 lttng_evaluation_destroy(notification->evaluation);
 155         }
 156         free(notification);
 157 }
 158
 159 const struct lttng_condition *lttng_notification_get_condition(
 160                 struct lttng_notification *notification)
 161 {
 162         return notification ? notification->condition : NULL;
 163 }
 164
 165 const struct lttng_evaluation *lttng_notification_get_evaluation(
 166                 struct lttng_notification *notification)
 167 {
 168         return notification ? notification->evaluation : NULL;
 169 }