| 1 | /* |
| 2 | * Copyright (C) 2019 - Jonathan Rajotte-Julien <jonathan.rajotte-julien@efficios.com> |
| 3 | * |
| 4 | * This library is free software; you can redistribute it and/or modify it |
| 5 | * under the terms of the GNU Lesser General Public License, version 2.1 only, |
| 6 | * as published by the Free Software Foundation. |
| 7 | * |
| 8 | * This library is distributed in the hope that it will be useful, but WITHOUT |
| 9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License |
| 11 | * for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU Lesser General Public License |
| 14 | * along with this library; if not, write to the Free Software Foundation, |
| 15 | * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 16 | */ |
| 17 | |
| 18 | #include <lttng/event-rule/event-rule-internal.h> |
| 19 | #include <lttng/event-rule/uprobe-internal.h> |
| 20 | #include <lttng/userspace-probe-internal.h> |
| 21 | #include <common/macros.h> |
| 22 | #include <common/error.h> |
| 23 | #include <common/runas.h> |
| 24 | #include <assert.h> |
| 25 | |
| 26 | #define IS_UPROBE_EVENT_RULE(rule) ( \ |
| 27 | lttng_event_rule_get_type(rule) == LTTNG_EVENT_RULE_TYPE_UPROBE \ |
| 28 | ) |
| 29 | |
| 30 | static |
| 31 | void lttng_event_rule_uprobe_destroy(struct lttng_event_rule *rule) |
| 32 | { |
| 33 | struct lttng_event_rule_uprobe *uprobe; |
| 34 | |
| 35 | uprobe = container_of(rule, struct lttng_event_rule_uprobe, |
| 36 | parent); |
| 37 | |
| 38 | lttng_userspace_probe_location_destroy(uprobe->location); |
| 39 | free(uprobe->name); |
| 40 | free(uprobe); |
| 41 | } |
| 42 | |
| 43 | static |
| 44 | bool lttng_event_rule_uprobe_validate( |
| 45 | const struct lttng_event_rule *rule) |
| 46 | { |
| 47 | bool valid = false; |
| 48 | struct lttng_event_rule_uprobe *uprobe; |
| 49 | |
| 50 | if (!rule) { |
| 51 | goto end; |
| 52 | } |
| 53 | |
| 54 | uprobe = container_of(rule, struct lttng_event_rule_uprobe, |
| 55 | parent); |
| 56 | |
| 57 | /* Required field */ |
| 58 | if (!uprobe->name) { |
| 59 | ERR("Invalid uprobe event rule: a pattern must be set."); |
| 60 | goto end; |
| 61 | } |
| 62 | |
| 63 | if (!uprobe->location) { |
| 64 | ERR("Invalid uprobe event rule: a location must be set."); |
| 65 | goto end; |
| 66 | } |
| 67 | |
| 68 | /* TODO should we validate the probe location? */ |
| 69 | |
| 70 | valid = true; |
| 71 | end: |
| 72 | return valid; |
| 73 | } |
| 74 | |
| 75 | static |
| 76 | int lttng_event_rule_uprobe_serialize( |
| 77 | const struct lttng_event_rule *rule, |
| 78 | struct lttng_dynamic_buffer *buf, |
| 79 | int *fd_to_send) |
| 80 | { |
| 81 | int ret; |
| 82 | size_t name_len, header_offset, size_before_probe; |
| 83 | struct lttng_event_rule_uprobe *uprobe; |
| 84 | struct lttng_event_rule_uprobe_comm uprobe_comm = { 0 }; |
| 85 | struct lttng_event_rule_uprobe_comm *header; |
| 86 | |
| 87 | if (!rule || !IS_UPROBE_EVENT_RULE(rule)) { |
| 88 | ret = -1; |
| 89 | goto end; |
| 90 | } |
| 91 | |
| 92 | header_offset = buf->size; |
| 93 | |
| 94 | DBG("Serializing uprobe event rule"); |
| 95 | uprobe = container_of( |
| 96 | rule, struct lttng_event_rule_uprobe, parent); |
| 97 | |
| 98 | name_len = strlen(uprobe->name) + 1; |
| 99 | |
| 100 | uprobe_comm.name_len = name_len; |
| 101 | |
| 102 | ret = lttng_dynamic_buffer_append( |
| 103 | buf, &uprobe_comm, sizeof(uprobe_comm)); |
| 104 | if (ret) { |
| 105 | goto end; |
| 106 | } |
| 107 | ret = lttng_dynamic_buffer_append(buf, uprobe->name, |
| 108 | name_len); |
| 109 | if (ret) { |
| 110 | goto end; |
| 111 | } |
| 112 | |
| 113 | size_before_probe = buf->size; |
| 114 | |
| 115 | /* This serialize return the size taken in the buffer */ |
| 116 | /* TODO: should all serialize standardise on this? */ |
| 117 | ret = lttng_userspace_probe_location_serialize( |
| 118 | uprobe->location, buf, fd_to_send); |
| 119 | if (ret < 0) { |
| 120 | goto end; |
| 121 | } |
| 122 | |
| 123 | /* Update the header regarding the probe size */ |
| 124 | header = (struct lttng_event_rule_uprobe_comm *) ((char *) buf->data + header_offset); |
| 125 | header->location_len = buf->size - size_before_probe; |
| 126 | |
| 127 | ret = 0; |
| 128 | |
| 129 | end: |
| 130 | return ret; |
| 131 | } |
| 132 | |
| 133 | static |
| 134 | bool lttng_event_rule_uprobe_is_equal(const struct lttng_event_rule *_a, |
| 135 | const struct lttng_event_rule *_b) |
| 136 | { |
| 137 | bool is_equal = false; |
| 138 | struct lttng_event_rule_uprobe *a, *b; |
| 139 | |
| 140 | a = container_of(_a, struct lttng_event_rule_uprobe, parent); |
| 141 | b = container_of(_b, struct lttng_event_rule_uprobe, parent); |
| 142 | |
| 143 | /* uprobe is invalid if this is not true */ |
| 144 | assert(a->name); |
| 145 | assert(b->name); |
| 146 | if (strcmp(a->name, b->name)) { |
| 147 | goto end; |
| 148 | } |
| 149 | |
| 150 | assert(a->location); |
| 151 | assert(b->location); |
| 152 | is_equal = lttng_userspace_probe_location_is_equal(a->location, b->location); |
| 153 | end: |
| 154 | return is_equal; |
| 155 | } |
| 156 | |
| 157 | static |
| 158 | enum lttng_error_code lttng_event_rule_uprobe_populate(struct lttng_event_rule *rule, uid_t uid, gid_t gid) |
| 159 | { |
| 160 | /* Nothing to do */ |
| 161 | return LTTNG_OK; |
| 162 | } |
| 163 | |
| 164 | static const char *lttng_event_rule_uprobe_get_filter( |
| 165 | const struct lttng_event_rule *rule) |
| 166 | { |
| 167 | /* Unsupported */ |
| 168 | return NULL; |
| 169 | } |
| 170 | |
| 171 | static const struct lttng_filter_bytecode * |
| 172 | lttng_event_rule_uprobe_get_filter_bytecode(const struct lttng_event_rule *rule) |
| 173 | { |
| 174 | /* Unsupported */ |
| 175 | return NULL; |
| 176 | } |
| 177 | |
| 178 | static |
| 179 | struct lttng_event_exclusion *lttng_event_rule_uprobe_generate_exclusions(struct lttng_event_rule *rule) |
| 180 | { |
| 181 | /* Unsupported */ |
| 182 | return NULL; |
| 183 | } |
| 184 | |
| 185 | struct lttng_event_rule *lttng_event_rule_uprobe_create() |
| 186 | { |
| 187 | struct lttng_event_rule_uprobe *rule; |
| 188 | |
| 189 | rule = zmalloc(sizeof(struct lttng_event_rule_uprobe)); |
| 190 | if (!rule) { |
| 191 | return NULL; |
| 192 | } |
| 193 | |
| 194 | lttng_event_rule_init(&rule->parent, LTTNG_EVENT_RULE_TYPE_UPROBE); |
| 195 | rule->parent.validate = lttng_event_rule_uprobe_validate; |
| 196 | rule->parent.serialize = lttng_event_rule_uprobe_serialize; |
| 197 | rule->parent.equal = lttng_event_rule_uprobe_is_equal; |
| 198 | rule->parent.destroy = lttng_event_rule_uprobe_destroy; |
| 199 | rule->parent.populate = lttng_event_rule_uprobe_populate; |
| 200 | rule->parent.get_filter = lttng_event_rule_uprobe_get_filter; |
| 201 | rule->parent.get_filter_bytecode = lttng_event_rule_uprobe_get_filter_bytecode; |
| 202 | rule->parent.generate_exclusions = lttng_event_rule_uprobe_generate_exclusions; |
| 203 | return &rule->parent; |
| 204 | } |
| 205 | |
| 206 | LTTNG_HIDDEN |
| 207 | ssize_t lttng_event_rule_uprobe_create_from_buffer( |
| 208 | const struct lttng_buffer_view *view, |
| 209 | struct lttng_event_rule **_event_rule) |
| 210 | { |
| 211 | ssize_t ret, offset = 0; |
| 212 | const struct lttng_event_rule_uprobe_comm *uprobe_comm; |
| 213 | const char *name; |
| 214 | struct lttng_buffer_view current_view; |
| 215 | struct lttng_event_rule *rule = NULL; |
| 216 | struct lttng_userspace_probe_location *location; |
| 217 | struct lttng_event_rule_uprobe *uprobe; |
| 218 | |
| 219 | if (!_event_rule) { |
| 220 | ret = -1; |
| 221 | goto end; |
| 222 | } |
| 223 | |
| 224 | if (view->size < sizeof(*uprobe_comm)) { |
| 225 | ERR("Failed to initialize from malformed event rule uprobe: buffer too short to contain header"); |
| 226 | ret = -1; |
| 227 | goto end; |
| 228 | } |
| 229 | |
| 230 | current_view = lttng_buffer_view_from_view(view, offset, sizeof(*uprobe_comm)); |
| 231 | uprobe_comm = (typeof(uprobe_comm)) current_view.data; |
| 232 | |
| 233 | if(!uprobe_comm) { |
| 234 | ret = -1; |
| 235 | goto end; |
| 236 | } |
| 237 | |
| 238 | rule = lttng_event_rule_uprobe_create(); |
| 239 | if (!rule) { |
| 240 | ERR("Failed to create event rule uprobe"); |
| 241 | ret = -1; |
| 242 | goto end; |
| 243 | } |
| 244 | |
| 245 | /* Skip to payload */ |
| 246 | offset += current_view.size; |
| 247 | |
| 248 | /* Map the name */ |
| 249 | current_view = lttng_buffer_view_from_view(view, offset, uprobe_comm->name_len); |
| 250 | name = current_view.data; |
| 251 | if (!name) { |
| 252 | ret = -1; |
| 253 | goto end; |
| 254 | } |
| 255 | |
| 256 | if (uprobe_comm->name_len == 1 || |
| 257 | name[uprobe_comm->name_len - 1] != '\0' || |
| 258 | strlen(name) != uprobe_comm->name_len - 1) { |
| 259 | /* |
| 260 | * Check that the name is not NULL, is NULL-terminated, and |
| 261 | * does not contain a NULL before the last byte. |
| 262 | */ |
| 263 | ret = -1; |
| 264 | goto end; |
| 265 | } |
| 266 | |
| 267 | /* Skip after the name */ |
| 268 | offset += uprobe_comm->name_len; |
| 269 | |
| 270 | /* Map the location */ |
| 271 | current_view = lttng_buffer_view_from_view(view, offset, uprobe_comm->location_len); |
| 272 | ret = lttng_userspace_probe_location_create_from_buffer(¤t_view, &location); |
| 273 | if (ret < 0) { |
| 274 | ret = -1; |
| 275 | goto end; |
| 276 | } |
| 277 | |
| 278 | assert(ret == uprobe_comm->location_len); |
| 279 | |
| 280 | /* Skip after the location */ |
| 281 | offset += uprobe_comm->location_len; |
| 282 | |
| 283 | uprobe = container_of(rule, struct lttng_event_rule_uprobe, parent); |
| 284 | uprobe->location = location; |
| 285 | |
| 286 | (void) lttng_event_rule_uprobe_set_name(rule, name); |
| 287 | |
| 288 | if (!lttng_event_rule_uprobe_validate(rule)) { |
| 289 | ret = -1; |
| 290 | goto end; |
| 291 | } |
| 292 | |
| 293 | *_event_rule = rule; |
| 294 | rule = NULL; |
| 295 | ret = offset; |
| 296 | end: |
| 297 | lttng_event_rule_destroy(rule); |
| 298 | return ret; |
| 299 | } |
| 300 | |
| 301 | enum lttng_event_rule_status lttng_event_rule_uprobe_set_location( |
| 302 | struct lttng_event_rule *rule, |
| 303 | const struct lttng_userspace_probe_location *location) |
| 304 | { |
| 305 | struct lttng_userspace_probe_location *location_copy = NULL; |
| 306 | struct lttng_event_rule_uprobe *uprobe; |
| 307 | enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK; |
| 308 | |
| 309 | if (!rule || !IS_UPROBE_EVENT_RULE(rule) || !location) { |
| 310 | status = LTTNG_EVENT_RULE_STATUS_INVALID; |
| 311 | goto end; |
| 312 | } |
| 313 | |
| 314 | uprobe = container_of(rule, struct lttng_event_rule_uprobe, |
| 315 | parent); |
| 316 | location_copy = lttng_userspace_probe_location_copy(location); |
| 317 | if (!location_copy) { |
| 318 | status = LTTNG_EVENT_RULE_STATUS_ERROR; |
| 319 | goto end; |
| 320 | } |
| 321 | |
| 322 | if (uprobe->location) { |
| 323 | lttng_userspace_probe_location_destroy(uprobe->location); |
| 324 | } |
| 325 | |
| 326 | uprobe->location = location_copy; |
| 327 | location_copy = NULL; |
| 328 | end: |
| 329 | lttng_userspace_probe_location_destroy(location_copy); |
| 330 | return status; |
| 331 | } |
| 332 | |
| 333 | enum lttng_event_rule_status lttng_event_rule_uprobe_get_location( |
| 334 | const struct lttng_event_rule *rule, |
| 335 | const struct lttng_userspace_probe_location **location) |
| 336 | { |
| 337 | enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK; |
| 338 | |
| 339 | if (!rule || !IS_UPROBE_EVENT_RULE(rule) || !location) { |
| 340 | status = LTTNG_EVENT_RULE_STATUS_INVALID; |
| 341 | goto end; |
| 342 | } |
| 343 | |
| 344 | *location = lttng_event_rule_uprobe_get_location_no_const(rule); |
| 345 | if (!*location) { |
| 346 | status = LTTNG_EVENT_RULE_STATUS_UNSET; |
| 347 | goto end; |
| 348 | } |
| 349 | |
| 350 | end: |
| 351 | return status; |
| 352 | |
| 353 | } |
| 354 | |
| 355 | LTTNG_HIDDEN |
| 356 | struct lttng_userspace_probe_location * |
| 357 | lttng_event_rule_uprobe_get_location_no_const( |
| 358 | const struct lttng_event_rule *rule) |
| 359 | { |
| 360 | struct lttng_event_rule_uprobe *uprobe; |
| 361 | assert(rule); |
| 362 | uprobe = container_of(rule, struct lttng_event_rule_uprobe, |
| 363 | parent); |
| 364 | |
| 365 | return uprobe->location; |
| 366 | } |
| 367 | |
| 368 | enum lttng_event_rule_status lttng_event_rule_uprobe_set_name( |
| 369 | struct lttng_event_rule *rule, const char *name) |
| 370 | { |
| 371 | char *name_copy = NULL; |
| 372 | struct lttng_event_rule_uprobe *uprobe; |
| 373 | enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK; |
| 374 | |
| 375 | if (!rule || !IS_UPROBE_EVENT_RULE(rule) || !name || |
| 376 | strlen(name) == 0) { |
| 377 | status = LTTNG_EVENT_RULE_STATUS_INVALID; |
| 378 | goto end; |
| 379 | } |
| 380 | |
| 381 | uprobe = container_of(rule, struct lttng_event_rule_uprobe, |
| 382 | parent); |
| 383 | name_copy = strdup(name); |
| 384 | if (!name_copy) { |
| 385 | status = LTTNG_EVENT_RULE_STATUS_ERROR; |
| 386 | goto end; |
| 387 | } |
| 388 | |
| 389 | if (uprobe->name) { |
| 390 | free(uprobe->name); |
| 391 | } |
| 392 | |
| 393 | uprobe->name = name_copy; |
| 394 | name_copy = NULL; |
| 395 | end: |
| 396 | return status; |
| 397 | } |
| 398 | |
| 399 | enum lttng_event_rule_status lttng_event_rule_uprobe_get_name( |
| 400 | const struct lttng_event_rule *rule, const char **name) |
| 401 | { |
| 402 | struct lttng_event_rule_uprobe *uprobe; |
| 403 | enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK; |
| 404 | |
| 405 | if (!rule || !IS_UPROBE_EVENT_RULE(rule) || !name) { |
| 406 | status = LTTNG_EVENT_RULE_STATUS_INVALID; |
| 407 | goto end; |
| 408 | } |
| 409 | |
| 410 | uprobe = container_of(rule, struct lttng_event_rule_uprobe, |
| 411 | parent); |
| 412 | if (!uprobe->name) { |
| 413 | status = LTTNG_EVENT_RULE_STATUS_UNSET; |
| 414 | goto end; |
| 415 | } |
| 416 | |
| 417 | *name = uprobe->name; |
| 418 | end: |
| 419 | return status; |
| 420 | } |