| 1 | /* |
| 2 | * Copyright (C) 2019 Jonathan Rajotte <jonathan.rajotte-julien@efficios.com> |
| 3 | * |
| 4 | * SPDX-License-Identifier: LGPL-2.1-only |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #include <assert.h> |
| 9 | #include <common/credentials.h> |
| 10 | #include <common/error.h> |
| 11 | #include <common/macros.h> |
| 12 | #include <common/payload.h> |
| 13 | #include <common/payload-view.h> |
| 14 | #include <common/runas.h> |
| 15 | #include <common/hashtable/hashtable.h> |
| 16 | #include <common/hashtable/utils.h> |
| 17 | #include <lttng/event-rule/event-rule-internal.h> |
| 18 | #include <lttng/event-rule/userspace-probe-internal.h> |
| 19 | #include <lttng/userspace-probe-internal.h> |
| 20 | |
| 21 | #define IS_UPROBE_EVENT_RULE(rule) \ |
| 22 | (lttng_event_rule_get_type(rule) == LTTNG_EVENT_RULE_TYPE_USERSPACE_PROBE) |
| 23 | |
| 24 | static void lttng_event_rule_userspace_probe_destroy(struct lttng_event_rule *rule) |
| 25 | { |
| 26 | struct lttng_event_rule_userspace_probe *uprobe; |
| 27 | |
| 28 | uprobe = container_of(rule, struct lttng_event_rule_userspace_probe, parent); |
| 29 | |
| 30 | lttng_userspace_probe_location_destroy(uprobe->location); |
| 31 | free(uprobe->name); |
| 32 | free(uprobe); |
| 33 | } |
| 34 | |
| 35 | static bool lttng_event_rule_userspace_probe_validate( |
| 36 | const struct lttng_event_rule *rule) |
| 37 | { |
| 38 | bool valid = false; |
| 39 | struct lttng_event_rule_userspace_probe *uprobe; |
| 40 | |
| 41 | if (!rule) { |
| 42 | goto end; |
| 43 | } |
| 44 | |
| 45 | uprobe = container_of(rule, struct lttng_event_rule_userspace_probe, parent); |
| 46 | |
| 47 | /* Required field. */ |
| 48 | if (!uprobe->name) { |
| 49 | ERR("Invalid uprobe event rule: a pattern must be set."); |
| 50 | goto end; |
| 51 | } |
| 52 | |
| 53 | if (!uprobe->location) { |
| 54 | ERR("Invalid uprobe event rule: a location must be set."); |
| 55 | goto end; |
| 56 | } |
| 57 | |
| 58 | valid = true; |
| 59 | end: |
| 60 | return valid; |
| 61 | } |
| 62 | |
| 63 | static int lttng_event_rule_userspace_probe_serialize( |
| 64 | const struct lttng_event_rule *rule, |
| 65 | struct lttng_payload *payload) |
| 66 | { |
| 67 | int ret; |
| 68 | size_t name_len, header_offset, size_before_probe; |
| 69 | struct lttng_event_rule_userspace_probe *uprobe; |
| 70 | struct lttng_event_rule_userspace_probe_comm uprobe_comm = {}; |
| 71 | struct lttng_event_rule_userspace_probe_comm *header; |
| 72 | |
| 73 | if (!rule || !IS_UPROBE_EVENT_RULE(rule)) { |
| 74 | ret = -1; |
| 75 | goto end; |
| 76 | } |
| 77 | |
| 78 | header_offset = payload->buffer.size; |
| 79 | |
| 80 | DBG("Serializing uprobe event rule."); |
| 81 | uprobe = container_of(rule, struct lttng_event_rule_userspace_probe, parent); |
| 82 | |
| 83 | name_len = strlen(uprobe->name) + 1; |
| 84 | |
| 85 | uprobe_comm.name_len = name_len; |
| 86 | |
| 87 | ret = lttng_dynamic_buffer_append( |
| 88 | &payload->buffer, &uprobe_comm, sizeof(uprobe_comm)); |
| 89 | if (ret) { |
| 90 | goto end; |
| 91 | } |
| 92 | ret = lttng_dynamic_buffer_append( |
| 93 | &payload->buffer, uprobe->name, name_len); |
| 94 | if (ret) { |
| 95 | goto end; |
| 96 | } |
| 97 | |
| 98 | size_before_probe = payload->buffer.size; |
| 99 | |
| 100 | /* This serialize return the size taken in the buffer. */ |
| 101 | ret = lttng_userspace_probe_location_serialize( |
| 102 | uprobe->location, payload); |
| 103 | if (ret < 0) { |
| 104 | goto end; |
| 105 | } |
| 106 | |
| 107 | /* Update the header regarding the probe size. */ |
| 108 | header = (struct lttng_event_rule_userspace_probe_comm |
| 109 | *) ((char *) payload->buffer.data + |
| 110 | header_offset); |
| 111 | header->location_len = payload->buffer.size - size_before_probe; |
| 112 | |
| 113 | ret = 0; |
| 114 | |
| 115 | end: |
| 116 | return ret; |
| 117 | } |
| 118 | |
| 119 | static bool lttng_event_rule_userspace_probe_is_equal(const struct lttng_event_rule *_a, |
| 120 | const struct lttng_event_rule *_b) |
| 121 | { |
| 122 | bool is_equal = false; |
| 123 | struct lttng_event_rule_userspace_probe *a, *b; |
| 124 | |
| 125 | a = container_of(_a, struct lttng_event_rule_userspace_probe, parent); |
| 126 | b = container_of(_b, struct lttng_event_rule_userspace_probe, parent); |
| 127 | |
| 128 | /* uprobe is invalid if this is not true. */ |
| 129 | assert(a->name); |
| 130 | assert(b->name); |
| 131 | if (strcmp(a->name, b->name)) { |
| 132 | goto end; |
| 133 | } |
| 134 | |
| 135 | assert(a->location); |
| 136 | assert(b->location); |
| 137 | is_equal = lttng_userspace_probe_location_is_equal( |
| 138 | a->location, b->location); |
| 139 | end: |
| 140 | return is_equal; |
| 141 | } |
| 142 | |
| 143 | static enum lttng_error_code lttng_event_rule_userspace_probe_generate_filter_bytecode( |
| 144 | struct lttng_event_rule *rule, |
| 145 | const struct lttng_credentials *creds) |
| 146 | { |
| 147 | /* Nothing to do. */ |
| 148 | return LTTNG_OK; |
| 149 | } |
| 150 | |
| 151 | static const char *lttng_event_rule_userspace_probe_get_filter( |
| 152 | const struct lttng_event_rule *rule) |
| 153 | { |
| 154 | /* Unsupported. */ |
| 155 | return NULL; |
| 156 | } |
| 157 | |
| 158 | static const struct lttng_bytecode * |
| 159 | lttng_event_rule_userspace_probe_get_filter_bytecode(const struct lttng_event_rule *rule) |
| 160 | { |
| 161 | /* Unsupported. */ |
| 162 | return NULL; |
| 163 | } |
| 164 | |
| 165 | static enum lttng_event_rule_generate_exclusions_status |
| 166 | lttng_event_rule_userspace_probe_generate_exclusions(const struct lttng_event_rule *rule, |
| 167 | struct lttng_event_exclusion **exclusions) |
| 168 | { |
| 169 | /* Unsupported. */ |
| 170 | *exclusions = NULL; |
| 171 | return LTTNG_EVENT_RULE_GENERATE_EXCLUSIONS_STATUS_NONE; |
| 172 | } |
| 173 | |
| 174 | static unsigned long |
| 175 | lttng_event_rule_userspace_probe_hash( |
| 176 | const struct lttng_event_rule *rule) |
| 177 | { |
| 178 | unsigned long hash; |
| 179 | struct lttng_event_rule_userspace_probe *urule = |
| 180 | container_of(rule, typeof(*urule), parent); |
| 181 | |
| 182 | hash = hash_key_ulong((void *) LTTNG_EVENT_RULE_TYPE_USERSPACE_PROBE, |
| 183 | lttng_ht_seed); |
| 184 | hash ^= hash_key_str(urule->name, lttng_ht_seed); |
| 185 | hash ^= lttng_userspace_probe_location_hash(urule->location); |
| 186 | |
| 187 | return hash; |
| 188 | } |
| 189 | |
| 190 | static |
| 191 | int userspace_probe_set_location( |
| 192 | struct lttng_event_rule_userspace_probe *uprobe, |
| 193 | const struct lttng_userspace_probe_location *location) |
| 194 | { |
| 195 | int ret; |
| 196 | struct lttng_userspace_probe_location *location_copy = NULL; |
| 197 | |
| 198 | if (!uprobe || !location || uprobe->location) { |
| 199 | ret = -1; |
| 200 | goto end; |
| 201 | } |
| 202 | |
| 203 | location_copy = lttng_userspace_probe_location_copy(location); |
| 204 | if (!location_copy) { |
| 205 | ret = -1; |
| 206 | goto end; |
| 207 | } |
| 208 | |
| 209 | uprobe->location = location_copy; |
| 210 | location_copy = NULL; |
| 211 | ret = 0; |
| 212 | end: |
| 213 | lttng_userspace_probe_location_destroy(location_copy); |
| 214 | return ret; |
| 215 | } |
| 216 | |
| 217 | struct lttng_event_rule *lttng_event_rule_userspace_probe_create( |
| 218 | const struct lttng_userspace_probe_location *location) |
| 219 | { |
| 220 | struct lttng_event_rule *rule = NULL; |
| 221 | struct lttng_event_rule_userspace_probe *urule; |
| 222 | |
| 223 | urule = zmalloc(sizeof(struct lttng_event_rule_userspace_probe)); |
| 224 | if (!urule) { |
| 225 | goto end; |
| 226 | } |
| 227 | |
| 228 | rule = &urule->parent; |
| 229 | lttng_event_rule_init(&urule->parent, LTTNG_EVENT_RULE_TYPE_USERSPACE_PROBE); |
| 230 | urule->parent.validate = lttng_event_rule_userspace_probe_validate; |
| 231 | urule->parent.serialize = lttng_event_rule_userspace_probe_serialize; |
| 232 | urule->parent.equal = lttng_event_rule_userspace_probe_is_equal; |
| 233 | urule->parent.destroy = lttng_event_rule_userspace_probe_destroy; |
| 234 | urule->parent.generate_filter_bytecode = |
| 235 | lttng_event_rule_userspace_probe_generate_filter_bytecode; |
| 236 | urule->parent.get_filter = lttng_event_rule_userspace_probe_get_filter; |
| 237 | urule->parent.get_filter_bytecode = |
| 238 | lttng_event_rule_userspace_probe_get_filter_bytecode; |
| 239 | urule->parent.generate_exclusions = |
| 240 | lttng_event_rule_userspace_probe_generate_exclusions; |
| 241 | urule->parent.hash = lttng_event_rule_userspace_probe_hash; |
| 242 | |
| 243 | if (userspace_probe_set_location(urule, location)) { |
| 244 | lttng_event_rule_destroy(rule); |
| 245 | rule = NULL; |
| 246 | } |
| 247 | |
| 248 | end: |
| 249 | return rule; |
| 250 | } |
| 251 | |
| 252 | LTTNG_HIDDEN |
| 253 | ssize_t lttng_event_rule_userspace_probe_create_from_payload( |
| 254 | struct lttng_payload_view *view, |
| 255 | struct lttng_event_rule **_event_rule) |
| 256 | { |
| 257 | ssize_t ret, offset = 0; |
| 258 | const struct lttng_event_rule_userspace_probe_comm *uprobe_comm; |
| 259 | const char *name; |
| 260 | struct lttng_buffer_view current_buffer_view; |
| 261 | struct lttng_event_rule *rule = NULL; |
| 262 | struct lttng_userspace_probe_location *location = NULL; |
| 263 | enum lttng_event_rule_status status; |
| 264 | |
| 265 | if (!_event_rule) { |
| 266 | ret = -1; |
| 267 | goto end; |
| 268 | } |
| 269 | |
| 270 | current_buffer_view = lttng_buffer_view_from_view( |
| 271 | &view->buffer, offset, sizeof(*uprobe_comm)); |
| 272 | if (!lttng_buffer_view_is_valid(¤t_buffer_view)) { |
| 273 | ERR("Failed to initialize from malformed event rule uprobe: buffer too short to contain header"); |
| 274 | ret = -1; |
| 275 | goto end; |
| 276 | } |
| 277 | |
| 278 | uprobe_comm = (typeof(uprobe_comm)) current_buffer_view.data; |
| 279 | |
| 280 | /* Skip to payload. */ |
| 281 | offset += current_buffer_view.size; |
| 282 | |
| 283 | /* Map the name. */ |
| 284 | current_buffer_view = lttng_buffer_view_from_view( |
| 285 | &view->buffer, offset, uprobe_comm->name_len); |
| 286 | if (!lttng_buffer_view_is_valid(¤t_buffer_view)) { |
| 287 | ret = -1; |
| 288 | goto end; |
| 289 | } |
| 290 | |
| 291 | name = current_buffer_view.data; |
| 292 | if (!lttng_buffer_view_contains_string(¤t_buffer_view, name, |
| 293 | uprobe_comm->name_len)) { |
| 294 | ret = -1; |
| 295 | goto end; |
| 296 | } |
| 297 | |
| 298 | /* Skip after the name. */ |
| 299 | offset += uprobe_comm->name_len; |
| 300 | |
| 301 | /* Map the location. */ |
| 302 | { |
| 303 | struct lttng_payload_view current_payload_view = |
| 304 | lttng_payload_view_from_view(view, offset, |
| 305 | uprobe_comm->location_len); |
| 306 | |
| 307 | if (!lttng_payload_view_is_valid(¤t_payload_view)) { |
| 308 | ERR("Failed to initialize from malformed event rule uprobe: buffer too short to contain location"); |
| 309 | ret = -1; |
| 310 | goto end; |
| 311 | } |
| 312 | |
| 313 | ret = lttng_userspace_probe_location_create_from_payload( |
| 314 | ¤t_payload_view, &location); |
| 315 | if (ret < 0) { |
| 316 | ret = -1; |
| 317 | goto end; |
| 318 | } |
| 319 | } |
| 320 | |
| 321 | assert(ret == uprobe_comm->location_len); |
| 322 | |
| 323 | /* Skip after the location. */ |
| 324 | offset += uprobe_comm->location_len; |
| 325 | |
| 326 | rule = lttng_event_rule_userspace_probe_create(location); |
| 327 | if (!rule) { |
| 328 | ERR("Failed to create event rule uprobe."); |
| 329 | ret = -1; |
| 330 | goto end; |
| 331 | } |
| 332 | |
| 333 | status = lttng_event_rule_userspace_probe_set_event_name(rule, name); |
| 334 | if (status != LTTNG_EVENT_RULE_STATUS_OK) { |
| 335 | ret = -1; |
| 336 | goto end; |
| 337 | } |
| 338 | |
| 339 | if (!lttng_event_rule_userspace_probe_validate(rule)) { |
| 340 | ret = -1; |
| 341 | goto end; |
| 342 | } |
| 343 | |
| 344 | *_event_rule = rule; |
| 345 | rule = NULL; |
| 346 | ret = offset; |
| 347 | end: |
| 348 | lttng_userspace_probe_location_destroy(location); |
| 349 | lttng_event_rule_destroy(rule); |
| 350 | return ret; |
| 351 | } |
| 352 | |
| 353 | |
| 354 | enum lttng_event_rule_status lttng_event_rule_userspace_probe_get_location( |
| 355 | const struct lttng_event_rule *rule, |
| 356 | const struct lttng_userspace_probe_location **location) |
| 357 | { |
| 358 | enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK; |
| 359 | |
| 360 | if (!rule || !IS_UPROBE_EVENT_RULE(rule) || !location) { |
| 361 | status = LTTNG_EVENT_RULE_STATUS_INVALID; |
| 362 | goto end; |
| 363 | } |
| 364 | |
| 365 | *location = lttng_event_rule_userspace_probe_get_location_mutable(rule); |
| 366 | if (!*location) { |
| 367 | status = LTTNG_EVENT_RULE_STATUS_UNSET; |
| 368 | goto end; |
| 369 | } |
| 370 | |
| 371 | end: |
| 372 | return status; |
| 373 | } |
| 374 | |
| 375 | LTTNG_HIDDEN |
| 376 | struct lttng_userspace_probe_location * |
| 377 | lttng_event_rule_userspace_probe_get_location_mutable( |
| 378 | const struct lttng_event_rule *rule) |
| 379 | { |
| 380 | struct lttng_event_rule_userspace_probe *uprobe; |
| 381 | |
| 382 | assert(rule); |
| 383 | uprobe = container_of(rule, struct lttng_event_rule_userspace_probe, parent); |
| 384 | |
| 385 | return uprobe->location; |
| 386 | } |
| 387 | |
| 388 | enum lttng_event_rule_status lttng_event_rule_userspace_probe_set_event_name( |
| 389 | struct lttng_event_rule *rule, const char *name) |
| 390 | { |
| 391 | char *name_copy = NULL; |
| 392 | struct lttng_event_rule_userspace_probe *uprobe; |
| 393 | enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK; |
| 394 | |
| 395 | if (!rule || !IS_UPROBE_EVENT_RULE(rule) || !name || |
| 396 | strlen(name) == 0) { |
| 397 | status = LTTNG_EVENT_RULE_STATUS_INVALID; |
| 398 | goto end; |
| 399 | } |
| 400 | |
| 401 | uprobe = container_of(rule, struct lttng_event_rule_userspace_probe, parent); |
| 402 | name_copy = strdup(name); |
| 403 | if (!name_copy) { |
| 404 | status = LTTNG_EVENT_RULE_STATUS_ERROR; |
| 405 | goto end; |
| 406 | } |
| 407 | |
| 408 | if (uprobe->name) { |
| 409 | free(uprobe->name); |
| 410 | } |
| 411 | |
| 412 | uprobe->name = name_copy; |
| 413 | name_copy = NULL; |
| 414 | end: |
| 415 | return status; |
| 416 | } |
| 417 | |
| 418 | enum lttng_event_rule_status lttng_event_rule_userspace_probe_get_event_name( |
| 419 | const struct lttng_event_rule *rule, const char **name) |
| 420 | { |
| 421 | struct lttng_event_rule_userspace_probe *uprobe; |
| 422 | enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK; |
| 423 | |
| 424 | if (!rule || !IS_UPROBE_EVENT_RULE(rule) || !name) { |
| 425 | status = LTTNG_EVENT_RULE_STATUS_INVALID; |
| 426 | goto end; |
| 427 | } |
| 428 | |
| 429 | uprobe = container_of(rule, struct lttng_event_rule_userspace_probe, parent); |
| 430 | if (!uprobe->name) { |
| 431 | status = LTTNG_EVENT_RULE_STATUS_UNSET; |
| 432 | goto end; |
| 433 | } |
| 434 | |
| 435 | *name = uprobe->name; |
| 436 | end: |
| 437 | return status; |
| 438 | } |