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 end:
  44         return notification;
  45 }
  46
  47 LTTNG_HIDDEN
  48 int lttng_notification_serialize(const struct lttng_notification *notification,
  49                 struct lttng_dynamic_buffer *buf)
  50 {
  51         int ret;
  52         size_t header_offset, size_before_payload;
  53         struct lttng_notification_comm notification_comm = { 0 };
  54         struct lttng_notification_comm *header;
  55
  56         header_offset = buf->size;
  57         ret = lttng_dynamic_buffer_append(buf, &notification_comm,
  58                         sizeof(notification_comm));
  59
  60         size_before_payload = buf->size;
  61         ret = lttng_condition_serialize(notification->condition,
  62                         buf);
  63         if (ret) {
  64                 goto end;
  65         }
  66
  67         ret = lttng_evaluation_serialize(notification->evaluation, buf);
  68         if (ret) {
  69                 goto end;
  70         }
  71
  72         /* Update payload size. */
  73         header = (struct lttng_notification_comm *) ((char *) buf->data + header_offset);
  74         header->length = (uint32_t) (buf->size - size_before_payload);
  75 end:
  76         return ret;
  77
  78 }
  79
  80 LTTNG_HIDDEN
  81 ssize_t lttng_notification_create_from_buffer(
  82                 const struct lttng_buffer_view *src_view,
  83                 struct lttng_notification **notification)
  84 {
  85         ssize_t ret, notification_size = 0, condition_size, evaluation_size;
  86         const struct lttng_notification_comm *notification_comm;
  87         struct lttng_condition *condition;
  88         struct lttng_evaluation *evaluation;
  89         struct lttng_buffer_view condition_view;
  90         struct lttng_buffer_view evaluation_view;
  91
  92         if (!src_view || !notification) {
  93                 ret = -1;
  94                 goto end;
  95         }
  96
  97         notification_comm =
  98                         (const struct lttng_notification_comm *) src_view->data;
  99         notification_size += sizeof(*notification_comm);
 100
 101         /* struct lttng_condition */
 102         condition_view = lttng_buffer_view_from_view(src_view,
 103                         sizeof(*notification_comm), -1);
 104         condition_size = lttng_condition_create_from_buffer(&condition_view,
 105                         &condition);
 106         if (condition_size < 0) {
 107                 ret = condition_size;
 108                 goto end;
 109         }
 110         notification_size += condition_size;
 111
 112         /* struct lttng_evaluation */
 113         evaluation_view = lttng_buffer_view_from_view(&condition_view,
 114                         condition_size, -1);
 115         evaluation_size = lttng_evaluation_create_from_buffer(&evaluation_view,
 116                         &evaluation);
 117         if (evaluation_size < 0) {
 118                 ret = evaluation_size;
 119                 goto end;
 120         }
 121         notification_size += evaluation_size;
 122
 123         /* Unexpected size of inner-elements; the buffer is corrupted. */
 124         if ((ssize_t) notification_comm->length !=
 125                         condition_size + evaluation_size) {
 126                 ret = -1;
 127                 goto error;
 128         }
 129
 130         *notification = lttng_notification_create(condition, evaluation);
 131         if (!*notification) {
 132                 ret = -1;
 133                 goto error;
 134         }
 135         ret = notification_size;
 136 end:
 137         return ret;
 138 error:
 139         lttng_condition_destroy(condition);
 140         lttng_evaluation_destroy(evaluation);
 141         return ret;
 142 }
 143
 144 void lttng_notification_destroy(struct lttng_notification *notification)
 145 {
 146         if (!notification) {
 147                 return;
 148         }
 149
 150         lttng_condition_destroy(notification->condition);
 151         lttng_evaluation_destroy(notification->evaluation);
 152         free(notification);
 153 }
 154
 155 const struct lttng_condition *lttng_notification_get_condition(
 156                 struct lttng_notification *notification)
 157 {
 158         return notification ? notification->condition : NULL;
 159 }
 160
 161 const struct lttng_evaluation *lttng_notification_get_evaluation(
 162                 struct lttng_notification *notification)
 163 {
 164         return notification ? notification->evaluation : NULL;
 165 }