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_put(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                         /* Ownership is transferred to the destruction handle. */
 177                         handle->location = location;
 178                         handle->communication.state = COMMUNICATION_STATE_END;
 179                 }
 180                 break;
 181         }
 182         default:
 183                 abort();
 184         }
 185
 186         /* Clear reception buffer on state transition. */
 187         if (lttng_dynamic_buffer_set_size(&handle->communication.buffer, 0)) {
 188                 abort();
 189         }
 190         return ret;
 191 }
 192
 193 static
 194 int handle_incoming_data(struct lttng_destruction_handle *handle)
 195 {
 196         int ret;
 197         ssize_t comm_ret;
 198         const size_t original_buffer_size = handle->communication.buffer.size;
 199
 200         /* Reserve space for reception. */
 201         ret = lttng_dynamic_buffer_set_size(&handle->communication.buffer,
 202                         original_buffer_size + handle->communication.bytes_left_to_receive);
 203         if (ret) {
 204                 goto end;
 205         }
 206
 207         comm_ret = lttcomm_recv_unix_sock(handle->communication.socket,
 208                         handle->communication.buffer.data + original_buffer_size,
 209                         handle->communication.bytes_left_to_receive);
 210         if (comm_ret <= 0) {
 211                 ret = -1;
 212                 goto end;
 213         }
 214
 215         handle->communication.bytes_left_to_receive -= comm_ret;
 216         if (handle->communication.bytes_left_to_receive == 0) {
 217                 ret = handle_state_transition(handle);
 218         } else {
 219                 ret = lttng_dynamic_buffer_set_size(
 220                                 &handle->communication.buffer,
 221                                 original_buffer_size + comm_ret);
 222         }
 223 end:
 224         return ret;
 225 }
 226
 227 enum lttng_destruction_handle_status
 228 lttng_destruction_handle_wait_for_completion(
 229                 struct lttng_destruction_handle *handle, int timeout_ms)
 230 {
 231         int ret;
 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                 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 = max_t(unsigned long, diff_ms, 1);
 309                 diff_ms = min_t(unsigned long, 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         };
 395         int sessiond_socket = -1;
 396         struct lttng_destruction_handle *handle = NULL;
 397
 398         if (!session_name) {
 399                 ret_code = LTTNG_ERR_INVALID;
 400                 goto error;
 401         }
 402
 403         ret = lttng_strncpy(lsm.session.name, session_name,
 404                         sizeof(lsm.session.name));
 405         if (ret) {
 406                 ret_code = LTTNG_ERR_INVALID;
 407                 goto error;
 408         }
 409
 410         ret = connect_sessiond();
 411         if (ret < 0) {
 412                 ret_code = LTTNG_ERR_NO_SESSIOND;
 413                 goto error;
 414         } else {
 415                 sessiond_socket = ret;
 416         }
 417
 418         handle = lttng_destruction_handle_create(sessiond_socket);
 419         if (!handle) {
 420                 ret_code = LTTNG_ERR_NOMEM;
 421                 goto error;
 422         }
 423
 424         comm_ret = lttcomm_send_creds_unix_sock(sessiond_socket, &lsm, sizeof(lsm));
 425         if (comm_ret < 0) {
 426                 ret_code = LTTNG_ERR_FATAL;
 427                 goto error;
 428         }
 429         sessiond_socket = -1;
 430
 431         /* Transfer the handle to the caller. */
 432         if (_handle) {
 433                 *_handle = handle;
 434                 handle = NULL;
 435         }
 436 error:
 437         if (sessiond_socket >= 0) {
 438                 ret = close(sessiond_socket);
 439                 if (ret < 0) {
 440                         PERROR("Failed to close the LTTng session daemon connection socket");
 441                 }
 442         }
 443         if (handle) {
 444                 lttng_destruction_handle_destroy(handle);
 445         }
 446         return ret_code;
 447 }