src/common/actions/action.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/action/action-internal.h>
   9 #include <lttng/action/notify-internal.h>
  10 #include <common/error.h>
  11 #include <assert.h>
  12
  13 enum lttng_action_type lttng_action_get_type(struct lttng_action *action)
  14 {
  15         return action ? action->type : LTTNG_ACTION_TYPE_UNKNOWN;
  16 }
  17
  18 LTTNG_HIDDEN
  19 enum lttng_action_type lttng_action_get_type_const(
  20                 const struct lttng_action *action)
  21 {
  22         return action->type;
  23 }
  24
  25 LTTNG_HIDDEN
  26 void lttng_action_init(
  27                 struct lttng_action *action,
  28                 enum lttng_action_type type,
  29                 action_validate_cb validate,
  30                 action_serialize_cb serialize,
  31                 action_destroy_cb destroy)
  32 {
  33         action->type = type;
  34         action->validate = validate;
  35         action->serialize = serialize;
  36         action->destroy = destroy;
  37 }
  38
  39 void lttng_action_destroy(struct lttng_action *action)
  40 {
  41         if (!action) {
  42                 return;
  43         }
  44
  45         assert(action->destroy);
  46         action->destroy(action);
  47 }
  48
  49 LTTNG_HIDDEN
  50 bool lttng_action_validate(struct lttng_action *action)
  51 {
  52         bool valid;
  53
  54         if (!action) {
  55                 valid = false;
  56                 goto end;
  57         }
  58
  59         if (!action->validate) {
  60                 /* Sub-class guarantees that it can never be invalid. */
  61                 valid = true;
  62                 goto end;
  63         }
  64
  65         valid = action->validate(action);
  66 end:
  67         return valid;
  68 }
  69
  70 LTTNG_HIDDEN
  71 int lttng_action_serialize(struct lttng_action *action,
  72                 struct lttng_dynamic_buffer *buf)
  73 {
  74         int ret;
  75         struct lttng_action_comm action_comm = {
  76                 .action_type = (int8_t) action->type,
  77         };
  78
  79         ret = lttng_dynamic_buffer_append(buf, &action_comm,
  80                         sizeof(action_comm));
  81         if (ret) {
  82                 goto end;
  83         }
  84
  85         ret = action->serialize(action, buf);
  86         if (ret) {
  87                 goto end;
  88         }
  89 end:
  90         return ret;
  91 }
  92
  93 LTTNG_HIDDEN
  94 ssize_t lttng_action_create_from_buffer(const struct lttng_buffer_view *view,
  95                 struct lttng_action **action)
  96 {
  97         ssize_t consumed_len, specific_action_consumed_len;
  98         const struct lttng_action_comm *action_comm;
  99         action_create_from_buffer_cb create_from_buffer_cb;
 100         struct lttng_buffer_view specific_action_view;
 101
 102         if (!view || !action) {
 103                 consumed_len = -1;
 104                 goto end;
 105         }
 106
 107         action_comm = (const struct lttng_action_comm *) view->data;
 108
 109         DBG("Deserializing action from buffer");
 110         switch (action_comm->action_type) {
 111         case LTTNG_ACTION_TYPE_NOTIFY:
 112                 create_from_buffer_cb = lttng_action_notify_create_from_buffer;
 113                 break;
 114         default:
 115                 consumed_len = -1;
 116                 goto end;
 117         }
 118
 119         /* Create buffer view for the action-type-specific data. */
 120         specific_action_view = lttng_buffer_view_from_view(view,
 121                         sizeof(struct lttng_action_comm),
 122                         view->size - sizeof(struct lttng_action_comm));
 123
 124         specific_action_consumed_len =
 125                         create_from_buffer_cb(&specific_action_view, action);
 126         if (specific_action_consumed_len < 0) {
 127                 ERR("Failed to create specific action from buffer.");
 128                 consumed_len = -1;
 129                 goto end;
 130         }
 131
 132         assert(*action);
 133
 134         consumed_len = sizeof(struct lttng_action_comm) +
 135                        specific_action_consumed_len;
 136
 137 end:
 138         return consumed_len;
 139 }