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

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