src/lib/lttng-ctl/destruction-handle.cpp

   1 /*
   2  * Copyright (C) 2019 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * SPDX-License-Identifier: LGPL-2.1-only
   5  *
   6  */
   7
   8 #include <lttng/destruction-handle.h>
   9 #include <lttng/rotation.h>
  10
  11 #include <common/optional.h>
  12 #include <common/compat/poll.h>
  13 #include <common/compat/time.h>
  14 #include <common/macros.h>
  15 #include <common/compat/poll.h>
  16 #include <common/dynamic-buffer.h>
  17 #include <common/buffer-view.h>
  18 #include <common/sessiond-comm/sessiond-comm.h>
  19 #include <lttng/location-internal.h>
  20 #include "lttng-ctl-helper.h"
  21
  22 #include <algorithm>
  23 #include <stdbool.h>
  24
  25 enum communication_state {
  26         COMMUNICATION_STATE_RECEIVE_LTTNG_MSG,
  27         COMMUNICATION_STATE_RECEIVE_COMMAND_HEADER,
  28         COMMUNICATION_STATE_RECEIVE_PAYLOAD,
  29         COMMUNICATION_STATE_END,
  30         COMMUNICATION_STATE_ERROR,
  31 };
  32
  33 struct lttng_destruction_handle {
  34         LTTNG_OPTIONAL(enum lttng_error_code) destruction_return_code;
  35         LTTNG_OPTIONAL(enum lttng_rotation_state) rotation_state;
  36         struct lttng_trace_archive_location *location;
  37         struct {
  38                 int socket;
  39                 struct lttng_poll_event events;
  40                 size_t bytes_left_to_receive;
  41                 enum communication_state state;
  42                 struct lttng_dynamic_buffer buffer;
  43                 LTTNG_OPTIONAL(size_t) data_size;
  44         } communication;
  45 };
  46
  47 void lttng_destruction_handle_destroy(struct lttng_destruction_handle *handle)
  48 {
  49         int ret;
  50
  51         if (!handle) {
  52                 return;
  53         }
  54
  55         if (handle->communication.socket >= 0) {
  56                 ret = close(handle->communication.socket);
  57                 if (ret) {
  58                         PERROR("Failed to close lttng-sessiond command socket");
  59                 }
  60         }
  61         lttng_poll_clean(&handle->communication.events);
  62         lttng_dynamic_buffer_reset(&handle->communication.buffer);
  63         lttng_trace_archive_location_put(handle->location);
  64         free(handle);
  65 }
  66
  67 static
  68 struct lttng_destruction_handle *lttng_destruction_handle_create(
  69                 int sessiond_socket)
  70 {
  71         int ret;
  72         struct lttng_destruction_handle *handle = (lttng_destruction_handle *) zmalloc(sizeof(*handle));
  73
  74         if (!handle) {
  75                 goto end;
  76         }
  77         lttng_dynamic_buffer_init(&handle->communication.buffer);
  78         handle->communication.socket = sessiond_socket;
  79         ret = lttng_poll_create(&handle->communication.events, 1, 0);
  80         if (ret) {
  81                 goto error;
  82         }
  83
  84         ret = lttng_poll_add(&handle->communication.events, sessiond_socket,
  85                         LPOLLIN | LPOLLHUP | LPOLLRDHUP | LPOLLERR);
  86         if (ret) {
  87                 goto error;
  88         }
  89
  90         handle->communication.bytes_left_to_receive =
  91                         sizeof(struct lttcomm_lttng_msg);
  92         handle->communication.state = COMMUNICATION_STATE_RECEIVE_LTTNG_MSG;
  93 end:
  94         return handle;
  95 error:
  96         lttng_destruction_handle_destroy(handle);
  97         return NULL;
  98 }
  99
 100 static
 101 int handle_state_transition(struct lttng_destruction_handle *handle)
 102 {
 103         int ret = 0;
 104
 105         LTTNG_ASSERT(handle->communication.bytes_left_to_receive == 0);
 106
 107         switch (handle->communication.state) {
 108         case COMMUNICATION_STATE_RECEIVE_LTTNG_MSG:
 109         {
 110                 const struct lttcomm_lttng_msg *msg =
 111                                 (typeof(msg)) handle->communication.buffer.data;
 112
 113                 LTTNG_OPTIONAL_SET(&handle->destruction_return_code,
 114                                 (enum lttng_error_code) msg->ret_code);
 115                 if (handle->destruction_return_code.value != LTTNG_OK) {
 116                         handle->communication.state = COMMUNICATION_STATE_END;
 117                         break;
 118                 } else if (msg->cmd_header_size != sizeof(struct lttcomm_session_destroy_command_header) ||
 119                                 msg->data_size > DEFAULT_MAX_TRACE_ARCHIVE_LOCATION_PAYLOAD_SIZE) {
 120                         handle->communication.state = COMMUNICATION_STATE_ERROR;
 121                         ret = -1;
 122                         break;
 123                 }
 124
 125                 handle->communication.state =
 126                                 COMMUNICATION_STATE_RECEIVE_COMMAND_HEADER;
 127                 handle->communication.bytes_left_to_receive =
 128                                 msg->cmd_header_size;
 129                 LTTNG_OPTIONAL_SET(&handle->communication.data_size,
 130                                 msg->data_size);
 131                 ret = lttng_dynamic_buffer_set_size(
 132                                 &handle->communication.buffer, 0);
 133                 LTTNG_ASSERT(!ret);
 134                 break;
 135         }
 136         case COMMUNICATION_STATE_RECEIVE_COMMAND_HEADER:
 137         {
 138                 const struct lttcomm_session_destroy_command_header *hdr =
 139                                 (typeof(hdr)) handle->communication.buffer.data;
 140
 141                 LTTNG_OPTIONAL_SET(&handle->rotation_state,
 142                                 (enum lttng_rotation_state) hdr->rotation_state);
 143                 switch (handle->rotation_state.value) {
 144                 case LTTNG_ROTATION_STATE_COMPLETED:
 145                         handle->communication.state =
 146                                         COMMUNICATION_STATE_RECEIVE_PAYLOAD;
 147                         handle->communication.bytes_left_to_receive =
 148                                         LTTNG_OPTIONAL_GET(handle->communication.data_size);
 149                         break;
 150                 case LTTNG_ROTATION_STATE_ERROR:
 151                 case LTTNG_ROTATION_STATE_NO_ROTATION:
 152                         handle->communication.state = COMMUNICATION_STATE_END;
 153                         break;
 154                 default:
 155                         handle->communication.state = COMMUNICATION_STATE_ERROR;
 156                         ret = -1;
 157                         break;
 158                 }
 159                 break;
 160         }
 161         case COMMUNICATION_STATE_RECEIVE_PAYLOAD:
 162         {
 163                 ssize_t location_ret;
 164                 struct lttng_trace_archive_location *location;
 165                 const struct lttng_buffer_view view =
 166                                 lttng_buffer_view_from_dynamic_buffer(
 167                                         &handle->communication.buffer, 0, -1);
 168
 169                 location_ret = lttng_trace_archive_location_create_from_buffer(
 170                                 &view, &location);
 171                 if (location_ret < 0) {
 172                         ERR("Failed to deserialize trace archive location");
 173                         handle->communication.state = COMMUNICATION_STATE_ERROR;
 174                         ret = -1;
 175                         break;
 176                 } else {
 177                         /* Ownership is transferred to the destruction handle. */
 178                         handle->location = location;
 179                         handle->communication.state = COMMUNICATION_STATE_END;
 180                 }
 181                 break;
 182         }
 183         default:
 184                 abort();
 185         }
 186
 187         /* Clear reception buffer on state transition. */
 188         if (lttng_dynamic_buffer_set_size(&handle->communication.buffer, 0)) {
 189                 abort();
 190         }
 191         return ret;
 192 }
 193
 194 static
 195 int handle_incoming_data(struct lttng_destruction_handle *handle)
 196 {
 197         int ret;
 198         ssize_t comm_ret;
 199         const size_t original_buffer_size = handle->communication.buffer.size;
 200
 201         /* Reserve space for reception. */
 202         ret = lttng_dynamic_buffer_set_size(&handle->communication.buffer,
 203                         original_buffer_size + handle->communication.bytes_left_to_receive);
 204         if (ret) {
 205                 goto end;
 206         }
 207
 208         comm_ret = lttcomm_recv_unix_sock(handle->communication.socket,
 209                         handle->communication.buffer.data + original_buffer_size,
 210                         handle->communication.bytes_left_to_receive);
 211         if (comm_ret <= 0) {
 212                 ret = -1;
 213                 goto end;
 214         }
 215
 216         handle->communication.bytes_left_to_receive -= comm_ret;
 217         if (handle->communication.bytes_left_to_receive == 0) {
 218                 ret = handle_state_transition(handle);
 219         } else {
 220                 ret = lttng_dynamic_buffer_set_size(
 221                                 &handle->communication.buffer,
 222                                 original_buffer_size + comm_ret);
 223         }
 224 end:
 225         return ret;
 226 }
 227
 228 enum lttng_destruction_handle_status
 229 lttng_destruction_handle_wait_for_completion(
 230                 struct lttng_destruction_handle *handle, int timeout_ms)
 231 {
 232         enum lttng_destruction_handle_status status;
 233         unsigned long time_left_ms = 0;
 234         const bool has_timeout = timeout_ms > 0;
 235         struct timespec initial_time;
 236
 237         if (!handle) {
 238                 status = LTTNG_DESTRUCTION_HANDLE_STATUS_INVALID;
 239                 goto end;
 240         }
 241
 242         if (handle->communication.state == COMMUNICATION_STATE_ERROR) {
 243                 status = LTTNG_DESTRUCTION_HANDLE_STATUS_ERROR;
 244                 goto end;
 245         } else if (handle->communication.state == COMMUNICATION_STATE_END) {
 246                 status = LTTNG_DESTRUCTION_HANDLE_STATUS_COMPLETED;
 247                 goto end;
 248         }
 249         if (has_timeout) {
 250                 int ret = lttng_clock_gettime(CLOCK_MONOTONIC, &initial_time);
 251                 if (ret) {
 252                         status = LTTNG_DESTRUCTION_HANDLE_STATUS_ERROR;
 253                         goto end;
 254                 }
 255                 time_left_ms = (unsigned long) timeout_ms;
 256         }
 257
 258         while (handle->communication.state != COMMUNICATION_STATE_END &&
 259                         (time_left_ms || !has_timeout)) {
 260                 int ret;
 261                 uint32_t revents;
 262                 struct timespec current_time, diff;
 263                 unsigned long diff_ms;
 264
 265                 ret = lttng_poll_wait(&handle->communication.events,
 266                                 has_timeout ? time_left_ms : -1);
 267                 if (ret == 0) {
 268                         /* timeout */
 269                         break;
 270                 } else if (ret < 0) {
 271                         status = LTTNG_DESTRUCTION_HANDLE_STATUS_ERROR;
 272                         goto end;
 273                 }
 274
 275                 /* The sessiond connection socket is the only monitored fd. */
 276                 revents = LTTNG_POLL_GETEV(&handle->communication.events, 0);
 277                 if (revents & LPOLLIN) {
 278                         ret = handle_incoming_data(handle);
 279                         if (ret) {
 280                                 handle->communication.state =
 281                                                 COMMUNICATION_STATE_ERROR;
 282                                 status = LTTNG_DESTRUCTION_HANDLE_STATUS_ERROR;
 283                                 goto end;
 284                         }
 285                 } else {
 286                         handle->communication.state = COMMUNICATION_STATE_ERROR;
 287                         status = LTTNG_DESTRUCTION_HANDLE_STATUS_ERROR;
 288                         goto end;
 289                 }
 290                 if (!has_timeout) {
 291                         continue;
 292                 }
 293
 294                 ret = lttng_clock_gettime(CLOCK_MONOTONIC, &current_time);
 295                 if (ret) {
 296                         status = LTTNG_DESTRUCTION_HANDLE_STATUS_ERROR;
 297                         goto end;
 298                 }
 299                 diff = timespec_abs_diff(initial_time, current_time);
 300                 ret = timespec_to_ms(diff, &diff_ms);
 301                 if (ret) {
 302                         ERR("Failed to compute elapsed time while waiting for completion");
 303                         status = LTTNG_DESTRUCTION_HANDLE_STATUS_ERROR;
 304                         goto end;
 305                 }
 306                 DBG("%lums elapsed while waiting for session destruction completion",
 307                                 diff_ms);
 308                 diff_ms = std::max(diff_ms, 1UL);
 309                 diff_ms = std::min(diff_ms, time_left_ms);
 310                 time_left_ms -= diff_ms;
 311         }
 312
 313         status = handle->communication.state == COMMUNICATION_STATE_END ?
 314                         LTTNG_DESTRUCTION_HANDLE_STATUS_COMPLETED :
 315                         LTTNG_DESTRUCTION_HANDLE_STATUS_TIMEOUT;
 316 end:
 317         return status;
 318 }
 319
 320 enum lttng_destruction_handle_status
 321 lttng_destruction_handle_get_rotation_state(
 322                 const struct lttng_destruction_handle *handle,
 323                 enum lttng_rotation_state *rotation_state)
 324 {
 325         enum lttng_destruction_handle_status status =
 326                         LTTNG_DESTRUCTION_HANDLE_STATUS_OK;
 327
 328         if (!handle || !rotation_state) {
 329                 status = LTTNG_DESTRUCTION_HANDLE_STATUS_INVALID;
 330                 goto end;
 331         }
 332
 333         if (!handle->rotation_state.is_set) {
 334                 status = LTTNG_DESTRUCTION_HANDLE_STATUS_INVALID;
 335                 goto end;
 336         }
 337         *rotation_state = handle->rotation_state.value;
 338 end:
 339         return status;
 340 }
 341
 342 enum lttng_destruction_handle_status
 343 lttng_destruction_handle_get_archive_location(
 344                 const struct lttng_destruction_handle *handle,
 345                 const struct lttng_trace_archive_location **location)
 346 {
 347         enum lttng_destruction_handle_status status =
 348                         LTTNG_DESTRUCTION_HANDLE_STATUS_OK;
 349
 350         if (!handle || !location) {
 351                 status = LTTNG_DESTRUCTION_HANDLE_STATUS_INVALID;
 352                 goto end;
 353         }
 354
 355         if (!handle->location) {
 356                 status = LTTNG_DESTRUCTION_HANDLE_STATUS_INVALID;
 357                 goto end;
 358         }
 359         *location = handle->location;
 360 end:
 361         return status;
 362 }
 363
 364 enum lttng_destruction_handle_status
 365 lttng_destruction_handle_get_result(
 366                 const struct lttng_destruction_handle *handle,
 367                 enum lttng_error_code *result)
 368 {
 369         enum lttng_destruction_handle_status status =
 370                         LTTNG_DESTRUCTION_HANDLE_STATUS_OK;
 371
 372         if (!handle || !result) {
 373                 status = LTTNG_DESTRUCTION_HANDLE_STATUS_INVALID;
 374                 goto end;
 375         }
 376
 377         if (!handle->destruction_return_code.is_set) {
 378                 status = LTTNG_DESTRUCTION_HANDLE_STATUS_INVALID;
 379                 goto end;
 380         }
 381         *result = handle->destruction_return_code.value;
 382 end:
 383         return status;
 384 }
 385
 386 enum lttng_error_code lttng_destroy_session_ext(const char *session_name,
 387                 struct lttng_destruction_handle **_handle)
 388 {
 389         int ret;
 390         ssize_t comm_ret;
 391         enum lttng_error_code ret_code = LTTNG_OK;
 392         struct lttcomm_session_msg lsm = {
 393                 .cmd_type = LTTNG_DESTROY_SESSION,
 394                 .session = {},
 395                 .domain = {},
 396                 .u = {},
 397                 .fd_count = 0,
 398         };
 399         int sessiond_socket = -1;
 400         struct lttng_destruction_handle *handle = NULL;
 401
 402         if (!session_name) {
 403                 ret_code = LTTNG_ERR_INVALID;
 404                 goto error;
 405         }
 406
 407         ret = lttng_strncpy(lsm.session.name, session_name,
 408                         sizeof(lsm.session.name));
 409         if (ret) {
 410                 ret_code = LTTNG_ERR_INVALID;
 411                 goto error;
 412         }
 413
 414         ret = connect_sessiond();
 415         if (ret < 0) {
 416                 ret_code = LTTNG_ERR_NO_SESSIOND;
 417                 goto error;
 418         } else {
 419                 sessiond_socket = ret;
 420         }
 421
 422         handle = lttng_destruction_handle_create(sessiond_socket);
 423         if (!handle) {
 424                 ret_code = LTTNG_ERR_NOMEM;
 425                 goto error;
 426         }
 427
 428         comm_ret = lttcomm_send_creds_unix_sock(sessiond_socket, &lsm, sizeof(lsm));
 429         if (comm_ret < 0) {
 430                 ret_code = LTTNG_ERR_FATAL;
 431                 goto error;
 432         }
 433         sessiond_socket = -1;
 434
 435         /* Transfer the handle to the caller. */
 436         if (_handle) {
 437                 *_handle = handle;
 438                 handle = NULL;
 439         }
 440 error:
 441         if (sessiond_socket >= 0) {
 442                 ret = close(sessiond_socket);
 443                 if (ret < 0) {
 444                         PERROR("Failed to close the LTTng session daemon connection socket");
 445                 }
 446         }
 447         if (handle) {
 448                 lttng_destruction_handle_destroy(handle);
 449         }
 450         return ret_code;
 451 }