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

   1 /*
   2  * Copyright (C) 2019 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * This library is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU Lesser General Public License, version 2.1 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This library is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
  11  * for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public License
  14  * along with this library; if not, write to the Free Software Foundation,
  15  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  16  */
  17
  18 #include <lttng/destruction-handle.h>
  19 #include <lttng/rotation.h>
  20
  21 #include <common/optional.h>
  22 #include <common/compat/poll.h>
  23 #include <common/compat/time.h>
  24 #include <common/macros.h>
  25 #include <common/compat/poll.h>
  26 #include <common/dynamic-buffer.h>
  27 #include <common/buffer-view.h>
  28 #include <common/sessiond-comm/sessiond-comm.h>
  29 #include <lttng/location-internal.h>
  30 #include "lttng-ctl-helper.h"
  31
  32 #include <stdbool.h>
  33
  34 enum communication_state {
  35         COMMUNICATION_STATE_RECEIVE_LTTNG_MSG,
  36         COMMUNICATION_STATE_RECEIVE_COMMAND_HEADER,
  37         COMMUNICATION_STATE_RECEIVE_PAYLOAD,
  38         COMMUNICATION_STATE_END,
  39         COMMUNICATION_STATE_ERROR,
  40 };
  41
  42 struct lttng_destruction_handle {
  43         LTTNG_OPTIONAL(enum lttng_error_code) destruction_return_code;
  44         LTTNG_OPTIONAL(enum lttng_rotation_state) rotation_state;
  45         struct lttng_trace_archive_location *location;
  46         struct {
  47                 int socket;
  48                 struct lttng_poll_event events;
  49                 size_t bytes_left_to_receive;
  50                 enum communication_state state;
  51                 struct lttng_dynamic_buffer buffer;
  52                 LTTNG_OPTIONAL(size_t) data_size;
  53         } communication;
  54 };
  55
  56 void lttng_destruction_handle_destroy(struct lttng_destruction_handle *handle)
  57 {
  58         int ret;
  59
  60         if (!handle) {
  61                 return;
  62         }
  63
  64         if (handle->communication.socket >= 0) {
  65                 ret = close(handle->communication.socket);
  66                 if (ret) {
  67                         PERROR("Failed to close lttng-sessiond command socket");
  68                 }
  69         }
  70         lttng_poll_clean(&handle->communication.events);
  71         lttng_dynamic_buffer_reset(&handle->communication.buffer);
  72         lttng_trace_archive_location_destroy(handle->location);
  73         free(handle);
  74 }
  75
  76 static
  77 struct lttng_destruction_handle *lttng_destruction_handle_create(
  78                 int sessiond_socket)
  79 {
  80         int ret;
  81         struct lttng_destruction_handle *handle = zmalloc(sizeof(*handle));
  82
  83         if (!handle) {
  84                 goto end;
  85         }
  86         lttng_dynamic_buffer_init(&handle->communication.buffer);
  87         handle->communication.socket = sessiond_socket;
  88         ret = lttng_poll_create(&handle->communication.events, 1, 0);
  89         if (ret) {
  90                 goto error;
  91         }
  92
  93         ret = lttng_poll_add(&handle->communication.events, sessiond_socket,
  94                         LPOLLIN | LPOLLHUP | LPOLLRDHUP | LPOLLERR);
  95         if (ret) {
  96                 goto error;
  97         }
  98
  99         handle->communication.bytes_left_to_receive =
 100                         sizeof(struct lttcomm_lttng_msg);
 101         handle->communication.state = COMMUNICATION_STATE_RECEIVE_LTTNG_MSG;
 102 end:
 103         return handle;
 104 error:
 105         lttng_destruction_handle_destroy(handle);
 106         return NULL;
 107 }
 108
 109 static
 110 int handle_state_transition(struct lttng_destruction_handle *handle)
 111 {
 112         int ret = 0;
 113
 114         assert(handle->communication.bytes_left_to_receive == 0);
 115
 116         switch (handle->communication.state) {
 117         case COMMUNICATION_STATE_RECEIVE_LTTNG_MSG:
 118         {
 119                 const struct lttcomm_lttng_msg *msg =
 120                                 (typeof(msg)) handle->communication.buffer.data;
 121
 122                 LTTNG_OPTIONAL_SET(&handle->destruction_return_code,
 123                                 (enum lttng_error_code) msg->ret_code);
 124                 if (handle->destruction_return_code.value != LTTNG_OK) {
 125                         handle->communication.state = COMMUNICATION_STATE_END;
 126                         break;
 127                 } else if (msg->cmd_header_size != sizeof(struct lttcomm_session_destroy_command_header) ||
 128                                 msg->data_size > DEFAULT_MAX_TRACE_ARCHIVE_LOCATION_PAYLOAD_SIZE) {
 129                         handle->communication.state = COMMUNICATION_STATE_ERROR;
 130                         ret = -1;
 131                         break;
 132                 }
 133
 134                 handle->communication.state =
 135                                 COMMUNICATION_STATE_RECEIVE_COMMAND_HEADER;
 136                 handle->communication.bytes_left_to_receive =
 137                                 msg->cmd_header_size;
 138                 LTTNG_OPTIONAL_SET(&handle->communication.data_size,
 139                                 msg->data_size);
 140                 ret = lttng_dynamic_buffer_set_size(
 141                                 &handle->communication.buffer, 0);
 142                 assert(!ret);
 143                 break;
 144         }
 145         case COMMUNICATION_STATE_RECEIVE_COMMAND_HEADER:
 146         {
 147                 const struct lttcomm_session_destroy_command_header *hdr =
 148                                 (typeof(hdr)) handle->communication.buffer.data;
 149
 150                 LTTNG_OPTIONAL_SET(&handle->rotation_state,
 151                                 (enum lttng_rotation_state) hdr->rotation_state);
 152                 switch (handle->rotation_state.value) {
 153                 case LTTNG_ROTATION_STATE_COMPLETED:
 154                         handle->communication.state =
 155                                         COMMUNICATION_STATE_RECEIVE_PAYLOAD;
 156                         handle->communication.bytes_left_to_receive =
 157                                         LTTNG_OPTIONAL_GET(handle->communication.data_size);
 158                         break;
 159                 case LTTNG_ROTATION_STATE_ERROR:
 160                 case LTTNG_ROTATION_STATE_NO_ROTATION:
 161                         handle->communication.state = COMMUNICATION_STATE_END;
 162                         break;
 163                 default:
 164                         handle->communication.state = COMMUNICATION_STATE_ERROR;
 165                         ret = -1;
 166                         break;
 167                 }
 168                 break;
 169         }
 170         case COMMUNICATION_STATE_RECEIVE_PAYLOAD:
 171         {
 172                 ssize_t location_ret;
 173                 struct lttng_trace_archive_location *location;
 174                 const struct lttng_buffer_view view =
 175                                 lttng_buffer_view_from_dynamic_buffer(
 176                                         &handle->communication.buffer, 0, -1);
 177
 178                 location_ret = lttng_trace_archive_location_create_from_buffer(
 179                                 &view, &location);
 180                 if (location_ret < 0) {
 181                         ERR("Failed to deserialize trace archive location");
 182                         handle->communication.state = COMMUNICATION_STATE_ERROR;
 183                         ret = -1;
 184                         break;
 185                 } else {
 186                         handle->location = location;
 187                         handle->communication.state = COMMUNICATION_STATE_END;
 188                 }
 189                 break;
 190         }
 191         default:
 192                 abort();
 193         }
 194
 195         /* Clear reception buffer on state transition. */
 196         if (lttng_dynamic_buffer_set_size(&handle->communication.buffer, 0)) {
 197                 abort();
 198         }
 199         return ret;
 200 }
 201
 202 static
 203 int handle_incoming_data(struct lttng_destruction_handle *handle)
 204 {
 205         int ret;
 206         ssize_t comm_ret;
 207         const size_t original_buffer_size = handle->communication.buffer.size;
 208
 209         /* Reserve space for reception. */
 210         ret = lttng_dynamic_buffer_set_size(&handle->communication.buffer,
 211                         original_buffer_size + handle->communication.bytes_left_to_receive);
 212         if (ret) {
 213                 goto end;
 214         }
 215
 216         comm_ret = lttcomm_recv_unix_sock(handle->communication.socket,
 217                         handle->communication.buffer.data + original_buffer_size,
 218                         handle->communication.bytes_left_to_receive);
 219         if (comm_ret <= 0) {
 220                 ret = -1;
 221                 goto end;
 222         }
 223
 224         handle->communication.bytes_left_to_receive -= comm_ret;
 225         if (handle->communication.bytes_left_to_receive == 0) {
 226                 ret = handle_state_transition(handle);
 227         } else {
 228                 ret = lttng_dynamic_buffer_set_size(
 229                                 &handle->communication.buffer,
 230                                 original_buffer_size + comm_ret);
 231         }
 232 end:
 233         return ret;
 234 }
 235
 236 enum lttng_destruction_handle_status
 237 lttng_destruction_handle_wait_for_completion(
 238                 struct lttng_destruction_handle *handle, int timeout_ms)
 239 {
 240         int ret;
 241         enum lttng_destruction_handle_status status;
 242         unsigned long time_left_ms = 0;
 243         const bool has_timeout = timeout_ms > 0;
 244         struct timespec initial_time;
 245
 246         if (!handle) {
 247                 status = LTTNG_DESTRUCTION_HANDLE_STATUS_INVALID;
 248                 goto end;
 249         }
 250
 251         if (handle->communication.state == COMMUNICATION_STATE_ERROR) {
 252                 status = LTTNG_DESTRUCTION_HANDLE_STATUS_ERROR;
 253                 goto end;
 254         } else if (handle->communication.state == COMMUNICATION_STATE_END) {
 255                 status = LTTNG_DESTRUCTION_HANDLE_STATUS_COMPLETED;
 256                 goto end;
 257         }
 258         if (has_timeout) {
 259                 ret = lttng_clock_gettime(CLOCK_MONOTONIC, &initial_time);
 260                 if (ret) {
 261                         status = LTTNG_DESTRUCTION_HANDLE_STATUS_ERROR;
 262                         goto end;
 263                 }
 264                 time_left_ms = (unsigned long) timeout_ms;
 265         }
 266
 267         while (handle->communication.state != COMMUNICATION_STATE_END &&
 268                         (time_left_ms || !has_timeout)) {
 269                 int ret;
 270                 uint32_t revents;
 271                 struct timespec current_time, diff;
 272                 unsigned long diff_ms;
 273
 274                 ret = lttng_poll_wait(&handle->communication.events,
 275                                 has_timeout ? time_left_ms : -1);
 276                 if (ret == 0) {
 277                         /* timeout */
 278                         break;
 279                 } else if (ret < 0) {
 280                         status = LTTNG_DESTRUCTION_HANDLE_STATUS_ERROR;
 281                         goto end;
 282                 }
 283
 284                 /* The sessiond connection socket is the only monitored fd. */
 285                 revents = LTTNG_POLL_GETEV(&handle->communication.events, 0);
 286                 if (revents & LPOLLIN) {
 287                         ret = handle_incoming_data(handle);
 288                         if (ret) {
 289                                 handle->communication.state =
 290                                                 COMMUNICATION_STATE_ERROR;
 291                                 status = LTTNG_DESTRUCTION_HANDLE_STATUS_ERROR;
 292                                 goto end;
 293                         }
 294                 } else {
 295                         handle->communication.state = COMMUNICATION_STATE_ERROR;
 296                         status = LTTNG_DESTRUCTION_HANDLE_STATUS_ERROR;
 297                         goto end;
 298                 }
 299                 if (!has_timeout) {
 300                         continue;
 301                 }
 302
 303                 ret = lttng_clock_gettime(CLOCK_MONOTONIC, &current_time);
 304                 if (ret) {
 305                         status = LTTNG_DESTRUCTION_HANDLE_STATUS_ERROR;
 306                         goto end;
 307                 }
 308                 diff = timespec_abs_diff(initial_time, current_time);
 309                 ret = timespec_to_ms(diff, &diff_ms);
 310                 if (ret) {
 311                         ERR("Failed to compute elapsed time while waiting for completion");
 312                         status = LTTNG_DESTRUCTION_HANDLE_STATUS_ERROR;
 313                         goto end;
 314                 }
 315                 DBG("%lums elapsed while waiting for session destruction completion",
 316                                 diff_ms);
 317                 diff_ms = max_t(unsigned long, diff_ms, 1);
 318                 diff_ms = min_t(unsigned long, diff_ms, time_left_ms);
 319                 time_left_ms -= diff_ms;
 320         }
 321
 322         status = handle->communication.state == COMMUNICATION_STATE_END ?
 323                         LTTNG_DESTRUCTION_HANDLE_STATUS_COMPLETED :
 324                         LTTNG_DESTRUCTION_HANDLE_STATUS_TIMEOUT;
 325 end:
 326         return status;
 327 }
 328
 329 enum lttng_destruction_handle_status
 330 lttng_destruction_handle_get_rotation_state(
 331                 const struct lttng_destruction_handle *handle,
 332                 enum lttng_rotation_state *rotation_state)
 333 {
 334         enum lttng_destruction_handle_status status =
 335                         LTTNG_DESTRUCTION_HANDLE_STATUS_OK;
 336
 337         if (!handle || !rotation_state) {
 338                 status = LTTNG_DESTRUCTION_HANDLE_STATUS_INVALID;
 339                 goto end;
 340         }
 341
 342         if (!handle->rotation_state.is_set) {
 343                 status = LTTNG_DESTRUCTION_HANDLE_STATUS_INVALID;
 344                 goto end;
 345         }
 346         *rotation_state = handle->rotation_state.value;
 347 end:
 348         return status;
 349 }
 350
 351 enum lttng_destruction_handle_status
 352 lttng_destruction_handle_get_archive_location(
 353                 const struct lttng_destruction_handle *handle,
 354                 const struct lttng_trace_archive_location **location)
 355 {
 356         enum lttng_destruction_handle_status status =
 357                         LTTNG_DESTRUCTION_HANDLE_STATUS_OK;
 358
 359         if (!handle || !location) {
 360                 status = LTTNG_DESTRUCTION_HANDLE_STATUS_INVALID;
 361                 goto end;
 362         }
 363
 364         if (!handle->location) {
 365                 status = LTTNG_DESTRUCTION_HANDLE_STATUS_INVALID;
 366                 goto end;
 367         }
 368         *location = handle->location;
 369 end:
 370         return status;
 371 }
 372
 373 enum lttng_destruction_handle_status
 374 lttng_destruction_handle_get_result(
 375                 const struct lttng_destruction_handle *handle,
 376                 enum lttng_error_code *result)
 377 {
 378         enum lttng_destruction_handle_status status =
 379                         LTTNG_DESTRUCTION_HANDLE_STATUS_OK;
 380
 381         if (!handle || !result) {
 382                 status = LTTNG_DESTRUCTION_HANDLE_STATUS_INVALID;
 383                 goto end;
 384         }
 385
 386         if (!handle->destruction_return_code.is_set) {
 387                 status = LTTNG_DESTRUCTION_HANDLE_STATUS_INVALID;
 388                 goto end;
 389         }
 390         *result = handle->destruction_return_code.value;
 391 end:
 392         return status;
 393 }
 394
 395 enum lttng_error_code lttng_destroy_session_ext(const char *session_name,
 396                 struct lttng_destruction_handle **_handle)
 397 {
 398         int ret;
 399         ssize_t comm_ret;
 400         enum lttng_error_code ret_code = LTTNG_OK;
 401         struct lttcomm_session_msg lsm = {
 402                 .cmd_type = LTTNG_DESTROY_SESSION,
 403         };
 404         int sessiond_socket = -1;
 405         struct lttng_destruction_handle *handle = NULL;
 406
 407         if (!session_name || !handle) {
 408                 ret_code = LTTNG_ERR_INVALID;
 409                 goto error;
 410         }
 411
 412         ret = lttng_strncpy(lsm.session.name, session_name,
 413                         sizeof(lsm.session.name));
 414         if (ret) {
 415                 ret_code = LTTNG_ERR_INVALID;
 416                 goto error;
 417         }
 418
 419         ret = connect_sessiond();
 420         if (ret < 0) {
 421                 ret_code = LTTNG_ERR_NO_SESSIOND;
 422                 goto error;
 423         } else {
 424                 sessiond_socket = ret;
 425         }
 426
 427         handle = lttng_destruction_handle_create(sessiond_socket);
 428         if (!handle) {
 429                 ret_code = LTTNG_ERR_NOMEM;
 430                 goto error;
 431         }
 432
 433         comm_ret = lttcomm_send_creds_unix_sock(sessiond_socket, &lsm, sizeof(lsm));
 434         if (comm_ret < 0) {
 435                 ret_code = LTTNG_ERR_FATAL;
 436                 goto error;
 437         }
 438         sessiond_socket = -1;
 439
 440         /* Transfer the handle to the caller. */
 441         if (_handle) {
 442                 *_handle = handle;
 443                 handle = NULL;
 444         }
 445 error:
 446         if (sessiond_socket >= 0) {
 447                 ret = close(sessiond_socket);
 448                 if (ret < 0) {
 449                         PERROR("Failed to close the LTTng session daemon connection socket");
 450                 }
 451         }
 452         if (handle) {
 453                 lttng_destruction_handle_destroy(handle);
 454         }
 455         return ret_code;
 456 }