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 <assert.h>
   9 #include <common/error.h>
  10 #include <lttng/action/action-internal.h>
  11 #include <lttng/action/notify-internal.h>
  12
  13 static const char *lttng_action_type_string(enum lttng_action_type action_type)
  14 {
  15         switch (action_type) {
  16         case LTTNG_ACTION_TYPE_UNKNOWN:
  17                 return "UNKNOWN";
  18         case LTTNG_ACTION_TYPE_NOTIFY:
  19                 return "NOTIFY";
  20         default:
  21                 return "???";
  22         }
  23 }
  24
  25 enum lttng_action_type lttng_action_get_type(struct lttng_action *action)
  26 {
  27         return action ? action->type : LTTNG_ACTION_TYPE_UNKNOWN;
  28 }
  29
  30 LTTNG_HIDDEN
  31 enum lttng_action_type lttng_action_get_type_const(
  32                 const struct lttng_action *action)
  33 {
  34         return action->type;
  35 }
  36
  37 LTTNG_HIDDEN
  38 void lttng_action_init(
  39                 struct lttng_action *action,
  40                 enum lttng_action_type type,
  41                 action_validate_cb validate,
  42                 action_serialize_cb serialize,
  43                 action_destroy_cb destroy)
  44 {
  45         action->type = type;
  46         action->validate = validate;
  47         action->serialize = serialize;
  48         action->destroy = destroy;
  49 }
  50
  51 void lttng_action_destroy(struct lttng_action *action)
  52 {
  53         if (!action) {
  54                 return;
  55         }
  56
  57         assert(action->destroy);
  58         action->destroy(action);
  59 }
  60
  61 LTTNG_HIDDEN
  62 bool lttng_action_validate(struct lttng_action *action)
  63 {
  64         bool valid;
  65
  66         if (!action) {
  67                 valid = false;
  68                 goto end;
  69         }
  70
  71         if (!action->validate) {
  72                 /* Sub-class guarantees that it can never be invalid. */
  73                 valid = true;
  74                 goto end;
  75         }
  76
  77         valid = action->validate(action);
  78 end:
  79         return valid;
  80 }
  81
  82 LTTNG_HIDDEN
  83 int lttng_action_serialize(struct lttng_action *action,
  84                 struct lttng_dynamic_buffer *buf)
  85 {
  86         int ret;
  87         struct lttng_action_comm action_comm = {
  88                 .action_type = (int8_t) action->type,
  89         };
  90
  91         ret = lttng_dynamic_buffer_append(buf, &action_comm,
  92                         sizeof(action_comm));
  93         if (ret) {
  94                 goto end;
  95         }
  96
  97         ret = action->serialize(action, buf);
  98         if (ret) {
  99                 goto end;
 100         }
 101 end:
 102         return ret;
 103 }
 104
 105 LTTNG_HIDDEN
 106 ssize_t lttng_action_create_from_buffer(const struct lttng_buffer_view *view,
 107                 struct lttng_action **action)
 108 {
 109         ssize_t consumed_len, specific_action_consumed_len;
 110         const struct lttng_action_comm *action_comm;
 111         action_create_from_buffer_cb create_from_buffer_cb;
 112         struct lttng_buffer_view specific_action_view;
 113
 114         if (!view || !action) {
 115                 consumed_len = -1;
 116                 goto end;
 117         }
 118
 119         action_comm = (const struct lttng_action_comm *) view->data;
 120
 121         DBG("Create action from buffer: action-type=%s",
 122                         lttng_action_type_string(action_comm->action_type));
 123
 124         switch (action_comm->action_type) {
 125         case LTTNG_ACTION_TYPE_NOTIFY:
 126                 create_from_buffer_cb = lttng_action_notify_create_from_buffer;
 127                 break;
 128         default:
 129                 ERR("Failed to create action from buffer, unhandled action type: action-type=%u (%s)",
 130                                 action_comm->action_type,
 131                                 lttng_action_type_string(
 132                                                 action_comm->action_type));
 133                 consumed_len = -1;
 134                 goto end;
 135         }
 136
 137         /* Create buffer view for the action-type-specific data. */
 138         specific_action_view = lttng_buffer_view_from_view(view,
 139                         sizeof(struct lttng_action_comm),
 140                         view->size - sizeof(struct lttng_action_comm));
 141
 142         specific_action_consumed_len =
 143                         create_from_buffer_cb(&specific_action_view, action);
 144         if (specific_action_consumed_len < 0) {
 145                 ERR("Failed to create specific action from buffer.");
 146                 consumed_len = -1;
 147                 goto end;
 148         }
 149
 150         assert(*action);
 151
 152         consumed_len = sizeof(struct lttng_action_comm) +
 153                        specific_action_consumed_len;
 154
 155 end:
 156         return consumed_len;
 157 }