src/common/notification.c

   1 /*
   2  * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * SPDX-License-Identifier: LGPL-2.1-only
   5  *
   6  */
   7
   8 #include <lttng/notification/notification-internal.h>
   9 #include <lttng/condition/condition-internal.h>
  10 #include <lttng/condition/evaluation-internal.h>
  11 #include <lttng/condition/condition.h>
  12 #include <lttng/condition/evaluation.h>
  13 #include <lttng/trigger/trigger-internal.h>
  14 #include <common/payload.h>
  15 #include <common/payload-view.h>
  16 #include <assert.h>
  17
  18 LTTNG_HIDDEN
  19 struct lttng_notification *lttng_notification_create(
  20                 struct lttng_trigger *trigger,
  21                 struct lttng_evaluation *evaluation)
  22 {
  23         struct lttng_notification *notification = NULL;
  24
  25         if (!trigger || !evaluation) {
  26                 goto end;
  27         }
  28
  29         notification = zmalloc(sizeof(struct lttng_notification));
  30         if (!notification) {
  31                 goto end;
  32         }
  33
  34         notification->trigger = trigger;
  35         notification->evaluation = evaluation;
  36 end:
  37         return notification;
  38 }
  39
  40 LTTNG_HIDDEN
  41 int lttng_notification_serialize(const struct lttng_notification *notification,
  42                 struct lttng_payload *payload)
  43 {
  44         int ret;
  45         size_t header_offset, size_before_payload;
  46         struct lttng_notification_comm notification_comm = { 0 };
  47         struct lttng_notification_comm *header;
  48
  49         header_offset = payload->buffer.size;
  50         ret = lttng_dynamic_buffer_append(&payload->buffer, &notification_comm,
  51                         sizeof(notification_comm));
  52         if (ret) {
  53                 goto end;
  54         }
  55
  56         size_before_payload = payload->buffer.size;
  57         ret = lttng_trigger_serialize(notification->trigger,
  58                         payload);
  59         if (ret) {
  60                 goto end;
  61         }
  62
  63         ret = lttng_evaluation_serialize(notification->evaluation, payload);
  64         if (ret) {
  65                 goto end;
  66         }
  67
  68         /* Update payload size. */
  69         header = (typeof(header)) (payload->buffer.data + header_offset);
  70         header->length = (uint32_t) (payload->buffer.size - size_before_payload);
  71 end:
  72         return ret;
  73
  74 }
  75
  76 LTTNG_HIDDEN
  77 ssize_t lttng_notification_create_from_payload(
  78                 struct lttng_payload_view *src_view,
  79                 struct lttng_notification **notification)
  80 {
  81         ssize_t ret, notification_size = 0, condition_size, evaluation_size;
  82         struct lttng_trigger *trigger;
  83         struct lttng_evaluation *evaluation;
  84         const struct lttng_notification_comm *notification_comm;
  85         const struct lttng_payload_view notification_comm_view =
  86                         lttng_payload_view_from_view(
  87                                         src_view, 0, sizeof(*notification_comm));
  88
  89         if (!src_view || !notification) {
  90                 ret = -1;
  91                 goto end;
  92         }
  93
  94         if (!lttng_payload_view_is_valid(&notification_comm_view)) {
  95                 /* Payload not large enough to contain the header. */
  96                 ret = -1;
  97                 goto end;
  98         }
  99
 100         notification_comm = (typeof(notification_comm)) notification_comm_view.buffer.data;
 101         notification_size += sizeof(*notification_comm);
 102         {
 103                 /* struct lttng_condition */
 104                 struct lttng_payload_view condition_view =
 105                                 lttng_payload_view_from_view(src_view,
 106                                                 notification_size, -1);
 107
 108                 condition_size = lttng_trigger_create_from_payload(
 109                                 &condition_view, &trigger);
 110         }
 111
 112         if (condition_size < 0) {
 113                 ret = condition_size;
 114                 goto end;
 115         }
 116
 117         notification_size += condition_size;
 118
 119         {
 120                 /* struct lttng_evaluation */
 121                 struct lttng_payload_view evaluation_view =
 122                                 lttng_payload_view_from_view(src_view,
 123                                                 notification_size, -1);
 124
 125                 evaluation_size = lttng_evaluation_create_from_payload(
 126                                 lttng_trigger_get_const_condition(trigger),
 127                                 &evaluation_view, &evaluation);
 128         }
 129
 130         if (evaluation_size < 0) {
 131                 ret = evaluation_size;
 132                 goto end;
 133         }
 134
 135         notification_size += evaluation_size;
 136
 137         /* Unexpected size of inner-elements; the buffer is corrupted. */
 138         if ((ssize_t) notification_comm->length !=
 139                         condition_size + evaluation_size) {
 140                 ret = -1;
 141                 goto error;
 142         }
 143
 144         *notification = lttng_notification_create(trigger, evaluation);
 145         if (!*notification) {
 146                 ret = -1;
 147                 goto error;
 148         }
 149         ret = notification_size;
 150 end:
 151         return ret;
 152 error:
 153         lttng_trigger_destroy(trigger);
 154         lttng_evaluation_destroy(evaluation);
 155         return ret;
 156 }
 157
 158 void lttng_notification_destroy(struct lttng_notification *notification)
 159 {
 160         if (!notification) {
 161                 return;
 162         }
 163
 164         lttng_trigger_destroy(notification->trigger);
 165         lttng_evaluation_destroy(notification->evaluation);
 166         free(notification);
 167 }
 168
 169 const struct lttng_condition *lttng_notification_get_condition(
 170                 struct lttng_notification *notification)
 171 {
 172         return notification ? lttng_trigger_get_const_condition(notification->trigger) : NULL;
 173 }
 174
 175 const struct lttng_evaluation *lttng_notification_get_evaluation(
 176                 struct lttng_notification *notification)
 177 {
 178         return notification ? notification->evaluation : NULL;
 179 }