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