| 1 | /* |
| 2 | * Copyright (C) 2019 Simon Marchi <simon.marchi@efficios.com> |
| 3 | * |
| 4 | * SPDX-License-Identifier: LGPL-2.1-only |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #include <assert.h> |
| 9 | #include <common/error.h> |
| 10 | #include <common/macros.h> |
| 11 | #include <common/snapshot.h> |
| 12 | #include <common/payload.h> |
| 13 | #include <common/payload-view.h> |
| 14 | #include <lttng/action/action-internal.h> |
| 15 | #include <lttng/action/snapshot-session-internal.h> |
| 16 | #include <lttng/action/snapshot-session.h> |
| 17 | #include <lttng/snapshot.h> |
| 18 | #include <lttng/snapshot-internal.h> |
| 19 | #include <inttypes.h> |
| 20 | |
| 21 | #define IS_SNAPSHOT_SESSION_ACTION(action) \ |
| 22 | (lttng_action_get_type(action) == LTTNG_ACTION_TYPE_SNAPSHOT_SESSION) |
| 23 | |
| 24 | struct lttng_action_snapshot_session { |
| 25 | struct lttng_action parent; |
| 26 | |
| 27 | /* Owned by this. */ |
| 28 | char *session_name; |
| 29 | |
| 30 | /* |
| 31 | * When non-NULL, use this custom output when taking the snapshot, |
| 32 | * rather than the session's registered snapshot output. |
| 33 | * |
| 34 | * Owned by this. |
| 35 | */ |
| 36 | struct lttng_snapshot_output *output; |
| 37 | }; |
| 38 | |
| 39 | struct lttng_action_snapshot_session_comm { |
| 40 | /* All string lengths include the trailing \0. */ |
| 41 | uint32_t session_name_len; |
| 42 | uint32_t snapshot_output_len; |
| 43 | |
| 44 | /* |
| 45 | * Variable data (all strings are null-terminated): |
| 46 | * |
| 47 | * - session name string |
| 48 | * - snapshot output object |
| 49 | * |
| 50 | */ |
| 51 | char data[]; |
| 52 | } LTTNG_PACKED; |
| 53 | |
| 54 | static struct lttng_action_snapshot_session * |
| 55 | action_snapshot_session_from_action(struct lttng_action *action) |
| 56 | { |
| 57 | assert(action); |
| 58 | |
| 59 | return container_of( |
| 60 | action, struct lttng_action_snapshot_session, parent); |
| 61 | } |
| 62 | |
| 63 | static const struct lttng_action_snapshot_session * |
| 64 | action_snapshot_session_from_action_const(const struct lttng_action *action) |
| 65 | { |
| 66 | assert(action); |
| 67 | |
| 68 | return container_of( |
| 69 | action, struct lttng_action_snapshot_session, parent); |
| 70 | } |
| 71 | |
| 72 | static bool lttng_action_snapshot_session_validate(struct lttng_action *action) |
| 73 | { |
| 74 | bool valid = false; |
| 75 | struct lttng_action_snapshot_session *action_snapshot_session; |
| 76 | |
| 77 | if (!action) { |
| 78 | goto end; |
| 79 | } |
| 80 | |
| 81 | action_snapshot_session = action_snapshot_session_from_action(action); |
| 82 | |
| 83 | /* A non-empty session name is mandatory. */ |
| 84 | if (!action_snapshot_session->session_name || |
| 85 | strlen(action_snapshot_session->session_name) == 0) { |
| 86 | goto end; |
| 87 | } |
| 88 | |
| 89 | if (action_snapshot_session->output && |
| 90 | !lttng_snapshot_output_validate(action_snapshot_session->output)) { |
| 91 | goto end; |
| 92 | } |
| 93 | |
| 94 | valid = true; |
| 95 | end: |
| 96 | return valid; |
| 97 | } |
| 98 | |
| 99 | static bool lttng_action_snapshot_session_is_equal( |
| 100 | const struct lttng_action *_a, const struct lttng_action *_b) |
| 101 | { |
| 102 | bool is_equal = false; |
| 103 | const struct lttng_action_snapshot_session *a, *b; |
| 104 | |
| 105 | a = action_snapshot_session_from_action_const(_a); |
| 106 | b = action_snapshot_session_from_action_const(_b); |
| 107 | |
| 108 | /* Action is not valid if this is not true. */ |
| 109 | assert(a->session_name); |
| 110 | assert(b->session_name); |
| 111 | if (strcmp(a->session_name, b->session_name)) { |
| 112 | goto end; |
| 113 | } |
| 114 | |
| 115 | if (a->output && b->output && |
| 116 | !lttng_snapshot_output_is_equal(a->output, b->output)) { |
| 117 | goto end; |
| 118 | } else if (!!a->output != !!b->output) { |
| 119 | goto end; |
| 120 | } |
| 121 | |
| 122 | is_equal = true; |
| 123 | end: |
| 124 | return is_equal; |
| 125 | } |
| 126 | |
| 127 | static size_t serialize_strlen(const char *str) |
| 128 | { |
| 129 | return str ? strlen(str) + 1 : 0; |
| 130 | } |
| 131 | |
| 132 | static int lttng_action_snapshot_session_serialize( |
| 133 | struct lttng_action *action, struct lttng_payload *payload) |
| 134 | { |
| 135 | struct lttng_action_snapshot_session *action_snapshot_session; |
| 136 | struct lttng_action_snapshot_session_comm comm = {}; |
| 137 | int ret; |
| 138 | size_t size_before_comm; |
| 139 | |
| 140 | assert(action); |
| 141 | assert(payload); |
| 142 | |
| 143 | size_before_comm = payload->buffer.size; |
| 144 | |
| 145 | action_snapshot_session = action_snapshot_session_from_action(action); |
| 146 | comm.session_name_len = |
| 147 | serialize_strlen(action_snapshot_session->session_name); |
| 148 | |
| 149 | /* Add header. */ |
| 150 | ret = lttng_dynamic_buffer_append( |
| 151 | &payload->buffer, &comm, sizeof(comm)); |
| 152 | if (ret) { |
| 153 | goto end; |
| 154 | } |
| 155 | |
| 156 | assert(action_snapshot_session->session_name); |
| 157 | DBG("Serializing snapshot session action: session-name: %s", |
| 158 | action_snapshot_session->session_name); |
| 159 | |
| 160 | /* Add session name. */ |
| 161 | ret = lttng_dynamic_buffer_append(&payload->buffer, |
| 162 | action_snapshot_session->session_name, |
| 163 | comm.session_name_len); |
| 164 | if (ret) { |
| 165 | goto end; |
| 166 | } |
| 167 | |
| 168 | /* Serialize the snapshot output object, if any. */ |
| 169 | if (action_snapshot_session->output) { |
| 170 | const size_t size_before_output = payload->buffer.size; |
| 171 | struct lttng_action_snapshot_session_comm *comm_in_payload; |
| 172 | |
| 173 | ret = lttng_snapshot_output_serialize( |
| 174 | action_snapshot_session->output, |
| 175 | payload); |
| 176 | if (ret) { |
| 177 | goto end; |
| 178 | } |
| 179 | |
| 180 | /* Adjust action length in header. */ |
| 181 | comm_in_payload = (typeof(comm_in_payload))( |
| 182 | payload->buffer.data + size_before_comm); |
| 183 | comm_in_payload->snapshot_output_len = |
| 184 | payload->buffer.size - size_before_output; |
| 185 | } |
| 186 | |
| 187 | end: |
| 188 | return ret; |
| 189 | } |
| 190 | |
| 191 | static void lttng_action_snapshot_session_destroy(struct lttng_action *action) |
| 192 | { |
| 193 | struct lttng_action_snapshot_session *action_snapshot_session; |
| 194 | |
| 195 | if (!action) { |
| 196 | goto end; |
| 197 | } |
| 198 | |
| 199 | action_snapshot_session = action_snapshot_session_from_action(action); |
| 200 | |
| 201 | free(action_snapshot_session->session_name); |
| 202 | lttng_snapshot_output_destroy(action_snapshot_session->output); |
| 203 | free(action_snapshot_session); |
| 204 | |
| 205 | end: |
| 206 | return; |
| 207 | } |
| 208 | |
| 209 | ssize_t lttng_action_snapshot_session_create_from_payload( |
| 210 | struct lttng_payload_view *view, |
| 211 | struct lttng_action **p_action) |
| 212 | { |
| 213 | ssize_t consumed_len; |
| 214 | const char *variable_data; |
| 215 | struct lttng_action *action; |
| 216 | enum lttng_action_status status; |
| 217 | struct lttng_snapshot_output *snapshot_output = NULL; |
| 218 | const struct lttng_action_snapshot_session_comm *comm; |
| 219 | const struct lttng_payload_view snapshot_session_comm_view = |
| 220 | lttng_payload_view_from_view( |
| 221 | view, 0, sizeof(*comm)); |
| 222 | |
| 223 | action = lttng_action_snapshot_session_create(); |
| 224 | if (!action) { |
| 225 | goto error; |
| 226 | } |
| 227 | |
| 228 | if (!lttng_payload_view_is_valid(&snapshot_session_comm_view)) { |
| 229 | /* Payload not large enough to contain the header. */ |
| 230 | goto error; |
| 231 | } |
| 232 | |
| 233 | comm = (typeof(comm)) snapshot_session_comm_view.buffer.data; |
| 234 | variable_data = (const char *) &comm->data; |
| 235 | |
| 236 | consumed_len = sizeof(struct lttng_action_snapshot_session_comm); |
| 237 | |
| 238 | if (!lttng_buffer_view_contains_string( |
| 239 | &view->buffer, variable_data, comm->session_name_len)) { |
| 240 | goto error; |
| 241 | } |
| 242 | |
| 243 | status = lttng_action_snapshot_session_set_session_name( |
| 244 | action, variable_data); |
| 245 | if (status != LTTNG_ACTION_STATUS_OK) { |
| 246 | goto error; |
| 247 | } |
| 248 | |
| 249 | variable_data += comm->session_name_len; |
| 250 | consumed_len += comm->session_name_len; |
| 251 | |
| 252 | /* If there is a snapshot output object, deserialize it. */ |
| 253 | if (comm->snapshot_output_len > 0) { |
| 254 | ssize_t snapshot_output_consumed_len; |
| 255 | enum lttng_action_status action_status; |
| 256 | struct lttng_payload_view snapshot_output_buffer_view = |
| 257 | lttng_payload_view_from_view(view, consumed_len, |
| 258 | comm->snapshot_output_len); |
| 259 | |
| 260 | if (!lttng_payload_view_is_valid(&snapshot_output_buffer_view)) { |
| 261 | ERR("Failed to create buffer view for snapshot output."); |
| 262 | goto error; |
| 263 | } |
| 264 | |
| 265 | snapshot_output_consumed_len = |
| 266 | lttng_snapshot_output_create_from_payload( |
| 267 | &snapshot_output_buffer_view, |
| 268 | &snapshot_output); |
| 269 | if (snapshot_output_consumed_len != comm->snapshot_output_len) { |
| 270 | ERR("Failed to deserialize snapshot output object: " |
| 271 | "consumed-len: %zd, expected-len: %" PRIu32, |
| 272 | snapshot_output_consumed_len, |
| 273 | comm->snapshot_output_len); |
| 274 | goto error; |
| 275 | } |
| 276 | |
| 277 | action_status = lttng_action_snapshot_session_set_output( |
| 278 | action, snapshot_output); |
| 279 | if (action_status != LTTNG_ACTION_STATUS_OK) { |
| 280 | goto error; |
| 281 | } |
| 282 | |
| 283 | /* Ownership has been transferred to the action. */ |
| 284 | snapshot_output = NULL; |
| 285 | } |
| 286 | |
| 287 | variable_data += comm->snapshot_output_len; |
| 288 | consumed_len += comm->snapshot_output_len; |
| 289 | *p_action = action; |
| 290 | action = NULL; |
| 291 | |
| 292 | goto end; |
| 293 | |
| 294 | error: |
| 295 | consumed_len = -1; |
| 296 | |
| 297 | end: |
| 298 | lttng_action_snapshot_session_destroy(action); |
| 299 | lttng_snapshot_output_destroy(snapshot_output); |
| 300 | |
| 301 | return consumed_len; |
| 302 | } |
| 303 | |
| 304 | struct lttng_action *lttng_action_snapshot_session_create(void) |
| 305 | { |
| 306 | struct lttng_action *action; |
| 307 | |
| 308 | action = zmalloc(sizeof(struct lttng_action_snapshot_session)); |
| 309 | if (!action) { |
| 310 | goto end; |
| 311 | } |
| 312 | |
| 313 | lttng_action_init(action, LTTNG_ACTION_TYPE_SNAPSHOT_SESSION, |
| 314 | lttng_action_snapshot_session_validate, |
| 315 | lttng_action_snapshot_session_serialize, |
| 316 | lttng_action_snapshot_session_is_equal, |
| 317 | lttng_action_snapshot_session_destroy); |
| 318 | |
| 319 | end: |
| 320 | return action; |
| 321 | } |
| 322 | |
| 323 | enum lttng_action_status lttng_action_snapshot_session_set_session_name( |
| 324 | struct lttng_action *action, const char *session_name) |
| 325 | { |
| 326 | struct lttng_action_snapshot_session *action_snapshot_session; |
| 327 | enum lttng_action_status status; |
| 328 | |
| 329 | if (!action || !IS_SNAPSHOT_SESSION_ACTION(action) || !session_name || |
| 330 | strlen(session_name) == 0) { |
| 331 | status = LTTNG_ACTION_STATUS_INVALID; |
| 332 | goto end; |
| 333 | } |
| 334 | |
| 335 | action_snapshot_session = action_snapshot_session_from_action(action); |
| 336 | |
| 337 | free(action_snapshot_session->session_name); |
| 338 | |
| 339 | action_snapshot_session->session_name = strdup(session_name); |
| 340 | if (!action_snapshot_session->session_name) { |
| 341 | status = LTTNG_ACTION_STATUS_ERROR; |
| 342 | goto end; |
| 343 | } |
| 344 | |
| 345 | status = LTTNG_ACTION_STATUS_OK; |
| 346 | end: |
| 347 | return status; |
| 348 | } |
| 349 | |
| 350 | enum lttng_action_status lttng_action_snapshot_session_get_session_name( |
| 351 | const struct lttng_action *action, const char **session_name) |
| 352 | { |
| 353 | const struct lttng_action_snapshot_session *action_snapshot_session; |
| 354 | enum lttng_action_status status; |
| 355 | |
| 356 | if (!action || !IS_SNAPSHOT_SESSION_ACTION(action) || !session_name) { |
| 357 | status = LTTNG_ACTION_STATUS_INVALID; |
| 358 | goto end; |
| 359 | } |
| 360 | |
| 361 | action_snapshot_session = action_snapshot_session_from_action_const(action); |
| 362 | |
| 363 | if (action_snapshot_session->session_name) { |
| 364 | *session_name = action_snapshot_session->session_name; |
| 365 | status = LTTNG_ACTION_STATUS_OK; |
| 366 | } else { |
| 367 | status = LTTNG_ACTION_STATUS_UNSET; |
| 368 | } |
| 369 | |
| 370 | end: |
| 371 | |
| 372 | return status; |
| 373 | } |
| 374 | |
| 375 | enum lttng_action_status lttng_action_snapshot_session_set_output( |
| 376 | struct lttng_action *action, |
| 377 | struct lttng_snapshot_output *output) |
| 378 | { |
| 379 | struct lttng_action_snapshot_session *action_snapshot_session; |
| 380 | enum lttng_action_status status; |
| 381 | |
| 382 | if (!action || !IS_SNAPSHOT_SESSION_ACTION(action) || !output) { |
| 383 | status = LTTNG_ACTION_STATUS_INVALID; |
| 384 | goto end; |
| 385 | } |
| 386 | |
| 387 | action_snapshot_session = action_snapshot_session_from_action(action); |
| 388 | |
| 389 | lttng_snapshot_output_destroy(action_snapshot_session->output); |
| 390 | action_snapshot_session->output = output; |
| 391 | |
| 392 | status = LTTNG_ACTION_STATUS_OK; |
| 393 | |
| 394 | end: |
| 395 | return status; |
| 396 | } |
| 397 | |
| 398 | enum lttng_action_status lttng_action_snapshot_session_get_output( |
| 399 | const struct lttng_action *action, |
| 400 | const struct lttng_snapshot_output **output) |
| 401 | { |
| 402 | const struct lttng_action_snapshot_session *action_snapshot_session; |
| 403 | enum lttng_action_status status; |
| 404 | |
| 405 | if (!action || !IS_SNAPSHOT_SESSION_ACTION(action)|| !output) { |
| 406 | status = LTTNG_ACTION_STATUS_INVALID; |
| 407 | goto end; |
| 408 | } |
| 409 | |
| 410 | action_snapshot_session = action_snapshot_session_from_action_const(action); |
| 411 | |
| 412 | if (action_snapshot_session->output) { |
| 413 | *output = action_snapshot_session->output; |
| 414 | status = LTTNG_ACTION_STATUS_OK; |
| 415 | } else { |
| 416 | status = LTTNG_ACTION_STATUS_UNSET; |
| 417 | } |
| 418 | |
| 419 | end: |
| 420 | return status; |
| 421 | } |