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