src/common/actions/start-session.c

   1 /*
   2  * Copyright (C) 2019 Simon Marchi <simon.marchi@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 <common/macros.h>
  11 #include <lttng/action/action-internal.h>
  12 #include <lttng/action/firing-policy-internal.h>
  13 #include <lttng/action/firing-policy.h>
  14 #include <lttng/action/start-session-internal.h>
  15 #include <lttng/action/start-session.h>
  16
  17 #define IS_START_SESSION_ACTION(action) \
  18         (lttng_action_get_type(action) == LTTNG_ACTION_TYPE_START_SESSION)
  19
  20 struct lttng_action_start_session {
  21         struct lttng_action parent;
  22
  23         /* Owned by this. */
  24         char *session_name;
  25         struct lttng_firing_policy *policy;
  26 };
  27
  28 struct lttng_action_start_session_comm {
  29         /* Includes the trailing \0. */
  30         uint32_t session_name_len;
  31
  32         /*
  33          * Variable data:
  34          *
  35          *  - session name (null terminated)
  36          *  - policy
  37          */
  38         char data[];
  39 } LTTNG_PACKED;
  40
  41 static struct lttng_action_start_session *action_start_session_from_action(
  42                 struct lttng_action *action)
  43 {
  44         assert(action);
  45
  46         return container_of(action, struct lttng_action_start_session, parent);
  47 }
  48
  49 static const struct lttng_action_start_session *
  50 action_start_session_from_action_const(const struct lttng_action *action)
  51 {
  52         assert(action);
  53
  54         return container_of(action, struct lttng_action_start_session, parent);
  55 }
  56
  57 static bool lttng_action_start_session_validate(struct lttng_action *action)
  58 {
  59         bool valid;
  60         struct lttng_action_start_session *action_start_session;
  61
  62         if (!action) {
  63                 valid = false;
  64                 goto end;
  65         }
  66
  67         action_start_session = action_start_session_from_action(action);
  68
  69         /* A non-empty session name is mandatory. */
  70         if (!action_start_session->session_name ||
  71                         strlen(action_start_session->session_name) == 0) {
  72                 valid = false;
  73                 goto end;
  74         }
  75
  76         valid = true;
  77 end:
  78         return valid;
  79 }
  80
  81 static bool lttng_action_start_session_is_equal(
  82                 const struct lttng_action *_a, const struct lttng_action *_b)
  83 {
  84         bool is_equal = false;
  85         struct lttng_action_start_session *a, *b;
  86
  87         a = container_of(_a, struct lttng_action_start_session, parent);
  88         b = container_of(_b, struct lttng_action_start_session, parent);
  89
  90         /* Action is not valid if this is not true. */
  91         assert(a->session_name);
  92         assert(b->session_name);
  93         if (strcmp(a->session_name, b->session_name)) {
  94                 goto end;
  95         }
  96
  97         is_equal = lttng_firing_policy_is_equal(a->policy, b->policy);
  98 end:
  99         return is_equal;
 100 }
 101
 102 static int lttng_action_start_session_serialize(
 103                 struct lttng_action *action, struct lttng_payload *payload)
 104 {
 105         struct lttng_action_start_session *action_start_session;
 106         struct lttng_action_start_session_comm comm;
 107         size_t session_name_len;
 108         int ret;
 109
 110         assert(action);
 111         assert(payload);
 112
 113         action_start_session = action_start_session_from_action(action);
 114
 115         assert(action_start_session->session_name);
 116
 117         DBG("Serializing start session action: session-name: %s",
 118                         action_start_session->session_name);
 119
 120         session_name_len = strlen(action_start_session->session_name) + 1;
 121         comm.session_name_len = session_name_len;
 122
 123         ret = lttng_dynamic_buffer_append(&payload->buffer, &comm, sizeof(comm));
 124         if (ret) {
 125                 ret = -1;
 126                 goto end;
 127         }
 128
 129         ret = lttng_dynamic_buffer_append(&payload->buffer,
 130                         action_start_session->session_name, session_name_len);
 131         if (ret) {
 132                 ret = -1;
 133                 goto end;
 134         }
 135
 136         ret = lttng_firing_policy_serialize(
 137                         action_start_session->policy, payload);
 138         if (ret) {
 139                 ret = -1;
 140                 goto end;
 141         }
 142
 143         ret = 0;
 144 end:
 145         return ret;
 146 }
 147
 148 static void lttng_action_start_session_destroy(struct lttng_action *action)
 149 {
 150         struct lttng_action_start_session *action_start_session;
 151
 152         if (!action) {
 153                 goto end;
 154         }
 155
 156         action_start_session = action_start_session_from_action(action);
 157
 158         lttng_firing_policy_destroy(action_start_session->policy);
 159         free(action_start_session->session_name);
 160         free(action_start_session);
 161
 162 end:
 163         return;
 164 }
 165
 166 ssize_t lttng_action_start_session_create_from_payload(
 167                 struct lttng_payload_view *view,
 168                 struct lttng_action **p_action)
 169 {
 170         ssize_t consumed_len, ret;
 171         const struct lttng_action_start_session_comm *comm;
 172         const char *session_name;
 173         struct lttng_action *action = NULL;
 174         enum lttng_action_status status;
 175         struct lttng_firing_policy *policy = NULL;
 176
 177         comm = (typeof(comm)) view->buffer.data;
 178         session_name = (const char *) &comm->data;
 179
 180         /* Session name */
 181         if (!lttng_buffer_view_contains_string(&view->buffer, session_name,
 182                             comm->session_name_len)) {
 183                 consumed_len = -1;
 184                 goto end;
 185         }
 186         consumed_len = sizeof(*comm) + comm->session_name_len;
 187
 188         /* Firing policy. */
 189         {
 190                 struct lttng_payload_view policy_view =
 191                                 lttng_payload_view_from_view(
 192                                                 view, consumed_len, -1);
 193                 ret = lttng_firing_policy_create_from_payload(
 194                                 &policy_view, &policy);
 195                 if (ret < 0) {
 196                         consumed_len = -1;
 197                         goto end;
 198                 }
 199                 consumed_len += ret;
 200         }
 201
 202         action = lttng_action_start_session_create();
 203         if (!action) {
 204                 consumed_len = -1;
 205                 goto end;
 206         }
 207
 208         status = lttng_action_start_session_set_session_name(
 209                         action, session_name);
 210         if (status != LTTNG_ACTION_STATUS_OK) {
 211                 consumed_len = -1;
 212                 goto end;
 213         }
 214
 215         assert(policy);
 216         status = lttng_action_start_session_set_firing_policy(action, policy);
 217         if (status != LTTNG_ACTION_STATUS_OK) {
 218                 consumed_len = -1;
 219                 goto end;
 220         }
 221
 222         *p_action = action;
 223         action = NULL;
 224
 225 end:
 226         lttng_firing_policy_destroy(policy);
 227         lttng_action_start_session_destroy(action);
 228
 229         return consumed_len;
 230 }
 231
 232 struct lttng_action *lttng_action_start_session_create(void)
 233 {
 234         struct lttng_action *action = NULL;
 235         struct lttng_firing_policy *policy = NULL;
 236         enum lttng_action_status status;
 237
 238         /* Create a every N = 1 firing policy. */
 239         policy = lttng_firing_policy_every_n_create(1);
 240         if (!policy) {
 241                 goto end;
 242         }
 243
 244         action = zmalloc(sizeof(struct lttng_action_start_session));
 245         if (!action) {
 246                 goto end;
 247         }
 248
 249         lttng_action_init(action, LTTNG_ACTION_TYPE_START_SESSION,
 250                         lttng_action_start_session_validate,
 251                         lttng_action_start_session_serialize,
 252                         lttng_action_start_session_is_equal,
 253                         lttng_action_start_session_destroy);
 254
 255         status = lttng_action_start_session_set_firing_policy(action, policy);
 256         if (status != LTTNG_ACTION_STATUS_OK) {
 257                 free(action);
 258                 action = NULL;
 259                 goto end;
 260         }
 261
 262 end:
 263         lttng_firing_policy_destroy(policy);
 264         return action;
 265 }
 266
 267 enum lttng_action_status lttng_action_start_session_set_session_name(
 268                 struct lttng_action *action, const char *session_name)
 269 {
 270         struct lttng_action_start_session *action_start_session;
 271         enum lttng_action_status status;
 272
 273         if (!action || !IS_START_SESSION_ACTION(action) || !session_name ||
 274                         strlen(session_name) == 0) {
 275                 status = LTTNG_ACTION_STATUS_INVALID;
 276                 goto end;
 277         }
 278
 279         action_start_session = action_start_session_from_action(action);
 280
 281         free(action_start_session->session_name);
 282
 283         action_start_session->session_name = strdup(session_name);
 284         if (!action_start_session->session_name) {
 285                 status = LTTNG_ACTION_STATUS_ERROR;
 286                 goto end;
 287         }
 288
 289         status = LTTNG_ACTION_STATUS_OK;
 290 end:
 291         return status;
 292 }
 293
 294 enum lttng_action_status lttng_action_start_session_get_session_name(
 295                 const struct lttng_action *action, const char **session_name)
 296 {
 297         const struct lttng_action_start_session *action_start_session;
 298         enum lttng_action_status status;
 299
 300         if (!action || !IS_START_SESSION_ACTION(action) || !session_name) {
 301                 status = LTTNG_ACTION_STATUS_INVALID;
 302                 goto end;
 303         }
 304
 305         action_start_session = action_start_session_from_action_const(action);
 306
 307         *session_name = action_start_session->session_name;
 308
 309         status = LTTNG_ACTION_STATUS_OK;
 310 end:
 311         return status;
 312 }
 313
 314 enum lttng_action_status lttng_action_start_session_set_firing_policy(
 315                 struct lttng_action *action,
 316                 const struct lttng_firing_policy *policy)
 317 {
 318         enum lttng_action_status status;
 319         struct lttng_action_start_session *start_session_action;
 320         struct lttng_firing_policy *copy = NULL;
 321
 322         if (!action || !policy || !IS_START_SESSION_ACTION(action)) {
 323                 status = LTTNG_ACTION_STATUS_INVALID;
 324                 goto end;
 325         }
 326
 327         copy = lttng_firing_policy_copy(policy);
 328         if (!copy) {
 329                 status = LTTNG_ACTION_STATUS_ERROR;
 330                 goto end;
 331         }
 332
 333         start_session_action = action_start_session_from_action(action);
 334
 335         /* Release the previous firing policy .*/
 336         lttng_firing_policy_destroy(start_session_action->policy);
 337
 338         /* Assign the policy. */
 339         start_session_action->policy = copy;
 340         status = LTTNG_ACTION_STATUS_OK;
 341         copy = NULL;
 342
 343 end:
 344         lttng_firing_policy_destroy(copy);
 345         return status;
 346 }
 347
 348 enum lttng_action_status lttng_action_start_session_get_firing_policy(
 349                 const struct lttng_action *action,
 350                 const struct lttng_firing_policy **policy)
 351 {
 352         enum lttng_action_status status;
 353         const struct lttng_action_start_session *start_session_action;
 354
 355         if (!action || !policy || !IS_START_SESSION_ACTION(action)) {
 356                 status = LTTNG_ACTION_STATUS_INVALID;
 357                 goto end;
 358         }
 359
 360         start_session_action = action_start_session_from_action_const(action);
 361
 362         *policy = start_session_action->policy;
 363         status = LTTNG_ACTION_STATUS_OK;
 364 end:
 365         return status;
 366 }