| 1 | /* |
| 2 | * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca> |
| 3 | * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License, version 2 only, |
| 7 | * as published by the Free Software Foundation. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, but WITHOUT |
| 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 12 | * more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License along |
| 15 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 16 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 17 | */ |
| 18 | |
| 19 | #define _LGPL_SOURCE |
| 20 | #include <errno.h> |
| 21 | #include <limits.h> |
| 22 | #include <stdio.h> |
| 23 | #include <stdlib.h> |
| 24 | #include <string.h> |
| 25 | #include <sys/wait.h> |
| 26 | #include <sys/types.h> |
| 27 | #include <sys/stat.h> |
| 28 | #include <unistd.h> |
| 29 | #include <fcntl.h> |
| 30 | #include <sched.h> |
| 31 | #include <signal.h> |
| 32 | #include <assert.h> |
| 33 | #include <signal.h> |
| 34 | |
| 35 | #include <common/lttng-kernel.h> |
| 36 | #include <common/common.h> |
| 37 | #include <common/utils.h> |
| 38 | #include <common/compat/getenv.h> |
| 39 | #include <common/compat/prctl.h> |
| 40 | #include <common/unix.h> |
| 41 | #include <common/defaults.h> |
| 42 | #include <common/lttng-elf.h> |
| 43 | |
| 44 | #include <lttng/constant.h> |
| 45 | |
| 46 | #include "runas.h" |
| 47 | |
| 48 | struct run_as_data; |
| 49 | struct run_as_ret; |
| 50 | typedef int (*run_as_fct)(struct run_as_data *data, struct run_as_ret *ret_value); |
| 51 | |
| 52 | struct run_as_mkdir_data { |
| 53 | char path[PATH_MAX]; |
| 54 | mode_t mode; |
| 55 | }; |
| 56 | |
| 57 | struct run_as_open_data { |
| 58 | char path[PATH_MAX]; |
| 59 | int flags; |
| 60 | mode_t mode; |
| 61 | }; |
| 62 | |
| 63 | struct run_as_unlink_data { |
| 64 | char path[PATH_MAX]; |
| 65 | }; |
| 66 | |
| 67 | struct run_as_rmdir_recursive_data { |
| 68 | char path[PATH_MAX]; |
| 69 | }; |
| 70 | |
| 71 | struct run_as_extract_elf_symbol_offset_data { |
| 72 | char function[LTTNG_SYMBOL_NAME_LEN]; |
| 73 | }; |
| 74 | |
| 75 | struct run_as_extract_sdt_probe_offsets_data { |
| 76 | char probe_name[LTTNG_SYMBOL_NAME_LEN]; |
| 77 | char provider_name[LTTNG_SYMBOL_NAME_LEN]; |
| 78 | }; |
| 79 | |
| 80 | struct run_as_mkdir_ret { |
| 81 | int ret; |
| 82 | }; |
| 83 | |
| 84 | struct run_as_open_ret { |
| 85 | int ret; |
| 86 | }; |
| 87 | |
| 88 | struct run_as_unlink_ret { |
| 89 | int ret; |
| 90 | }; |
| 91 | |
| 92 | struct run_as_rmdir_recursive_ret { |
| 93 | int ret; |
| 94 | }; |
| 95 | |
| 96 | struct run_as_extract_elf_symbol_offset_ret { |
| 97 | uint64_t offset; |
| 98 | }; |
| 99 | |
| 100 | struct run_as_extract_sdt_probe_offsets_ret { |
| 101 | uint32_t num_offset; |
| 102 | uint64_t offsets[LTTNG_KERNEL_MAX_UPROBE_NUM]; |
| 103 | }; |
| 104 | |
| 105 | enum run_as_cmd { |
| 106 | RUN_AS_MKDIR, |
| 107 | RUN_AS_OPEN, |
| 108 | RUN_AS_UNLINK, |
| 109 | RUN_AS_RMDIR_RECURSIVE, |
| 110 | RUN_AS_MKDIR_RECURSIVE, |
| 111 | RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET, |
| 112 | RUN_AS_EXTRACT_SDT_PROBE_OFFSETS, |
| 113 | }; |
| 114 | |
| 115 | struct run_as_data { |
| 116 | enum run_as_cmd cmd; |
| 117 | int fd; |
| 118 | union { |
| 119 | struct run_as_mkdir_data mkdir; |
| 120 | struct run_as_open_data open; |
| 121 | struct run_as_unlink_data unlink; |
| 122 | struct run_as_rmdir_recursive_data rmdir_recursive; |
| 123 | struct run_as_extract_elf_symbol_offset_data extract_elf_symbol_offset; |
| 124 | struct run_as_extract_sdt_probe_offsets_data extract_sdt_probe_offsets; |
| 125 | } u; |
| 126 | uid_t uid; |
| 127 | gid_t gid; |
| 128 | }; |
| 129 | |
| 130 | /* |
| 131 | * The run_as_ret structure holds the returned value and status of the command. |
| 132 | * |
| 133 | * The `u` union field holds the return value of the command; in most cases it |
| 134 | * represents the success or the failure of the command. In more complex |
| 135 | * commands, it holds a computed value. |
| 136 | * |
| 137 | * The _errno field is the errno recorded after the execution of the command. |
| 138 | * |
| 139 | * The _error fields is used the signify that return status of the command. For |
| 140 | * simple commands returning `int` the _error field will be the same as the |
| 141 | * ret_int field. In complex commands, it signify the success or failure of the |
| 142 | * command. |
| 143 | * |
| 144 | */ |
| 145 | struct run_as_ret { |
| 146 | int fd; |
| 147 | union { |
| 148 | struct run_as_mkdir_ret mkdir; |
| 149 | struct run_as_open_ret open; |
| 150 | struct run_as_unlink_ret unlink; |
| 151 | struct run_as_rmdir_recursive_ret rmdir_recursive; |
| 152 | struct run_as_extract_elf_symbol_offset_ret extract_elf_symbol_offset; |
| 153 | struct run_as_extract_sdt_probe_offsets_ret extract_sdt_probe_offsets; |
| 154 | } u; |
| 155 | int _errno; |
| 156 | bool _error; |
| 157 | }; |
| 158 | |
| 159 | struct run_as_worker { |
| 160 | pid_t pid; /* Worker PID. */ |
| 161 | int sockpair[2]; |
| 162 | char *procname; |
| 163 | }; |
| 164 | |
| 165 | /* Single global worker per process (for now). */ |
| 166 | static struct run_as_worker *global_worker; |
| 167 | /* Lock protecting the worker. */ |
| 168 | static pthread_mutex_t worker_lock = PTHREAD_MUTEX_INITIALIZER; |
| 169 | |
| 170 | #ifdef VALGRIND |
| 171 | static |
| 172 | int use_clone(void) |
| 173 | { |
| 174 | return 0; |
| 175 | } |
| 176 | #else |
| 177 | static |
| 178 | int use_clone(void) |
| 179 | { |
| 180 | return !lttng_secure_getenv("LTTNG_DEBUG_NOCLONE"); |
| 181 | } |
| 182 | #endif |
| 183 | |
| 184 | LTTNG_HIDDEN |
| 185 | int _utils_mkdir_recursive_unsafe(const char *path, mode_t mode); |
| 186 | |
| 187 | /* |
| 188 | * Create recursively directory using the FULL path. |
| 189 | */ |
| 190 | static |
| 191 | int _mkdir_recursive(struct run_as_data *data, struct run_as_ret *ret_value) |
| 192 | { |
| 193 | const char *path; |
| 194 | mode_t mode; |
| 195 | |
| 196 | path = data->u.mkdir.path; |
| 197 | mode = data->u.mkdir.mode; |
| 198 | |
| 199 | /* Safe to call as we have transitioned to the requested uid/gid. */ |
| 200 | ret_value->u.mkdir.ret = _utils_mkdir_recursive_unsafe(path, mode); |
| 201 | ret_value->_errno = errno; |
| 202 | ret_value->_error = (ret_value->u.mkdir.ret) ? true : false; |
| 203 | return ret_value->u.mkdir.ret; |
| 204 | } |
| 205 | |
| 206 | static |
| 207 | int _mkdir(struct run_as_data *data, struct run_as_ret *ret_value) |
| 208 | { |
| 209 | ret_value->u.mkdir.ret = mkdir(data->u.mkdir.path, data->u.mkdir.mode); |
| 210 | ret_value->_errno = errno; |
| 211 | ret_value->_error = (ret_value->u.mkdir.ret) ? true : false; |
| 212 | return ret_value->u.mkdir.ret; |
| 213 | } |
| 214 | |
| 215 | static |
| 216 | int _open(struct run_as_data *data, struct run_as_ret *ret_value) |
| 217 | { |
| 218 | ret_value->u.open.ret = open(data->u.open.path, data->u.open.flags, data->u.open.mode); |
| 219 | ret_value->fd = ret_value->u.open.ret; |
| 220 | ret_value->_errno = errno; |
| 221 | ret_value->_error = ret_value->u.open.ret < 0; |
| 222 | return ret_value->u.open.ret; |
| 223 | } |
| 224 | |
| 225 | static |
| 226 | int _unlink(struct run_as_data *data, struct run_as_ret *ret_value) |
| 227 | { |
| 228 | ret_value->u.unlink.ret = unlink(data->u.unlink.path); |
| 229 | ret_value->_errno = errno; |
| 230 | ret_value->_error = (ret_value->u.unlink.ret) ? true : false; |
| 231 | return ret_value->u.unlink.ret; |
| 232 | } |
| 233 | |
| 234 | static |
| 235 | int _rmdir_recursive(struct run_as_data *data, struct run_as_ret *ret_value) |
| 236 | { |
| 237 | ret_value->u.rmdir_recursive.ret = utils_recursive_rmdir(data->u.rmdir_recursive.path); |
| 238 | ret_value->_errno = errno; |
| 239 | ret_value->_error = (ret_value->u.rmdir_recursive.ret) ? true : false; |
| 240 | return ret_value->u.rmdir_recursive.ret; |
| 241 | } |
| 242 | |
| 243 | #ifdef HAVE_ELF_H |
| 244 | static |
| 245 | int _extract_elf_symbol_offset(struct run_as_data *data, |
| 246 | struct run_as_ret *ret_value) |
| 247 | { |
| 248 | int ret = 0; |
| 249 | ret_value->_error = false; |
| 250 | |
| 251 | ret = lttng_elf_get_symbol_offset(data->fd, |
| 252 | data->u.extract_elf_symbol_offset.function, |
| 253 | &ret_value->u.extract_elf_symbol_offset.offset); |
| 254 | if (ret) { |
| 255 | DBG("Failed to extract ELF function offset"); |
| 256 | ret_value->_error = true; |
| 257 | } |
| 258 | |
| 259 | return ret; |
| 260 | } |
| 261 | |
| 262 | static |
| 263 | int _extract_sdt_probe_offsets(struct run_as_data *data, |
| 264 | struct run_as_ret *ret_value) |
| 265 | { |
| 266 | int ret = 0; |
| 267 | uint64_t *offsets = NULL; |
| 268 | uint32_t num_offset; |
| 269 | |
| 270 | ret_value->_error = false; |
| 271 | |
| 272 | /* On success, this call allocates the offsets paramater. */ |
| 273 | ret = lttng_elf_get_sdt_probe_offsets(data->fd, |
| 274 | data->u.extract_sdt_probe_offsets.provider_name, |
| 275 | data->u.extract_sdt_probe_offsets.probe_name, |
| 276 | &offsets, &num_offset); |
| 277 | |
| 278 | if (ret) { |
| 279 | DBG("Failed to extract SDT probe offsets"); |
| 280 | ret_value->_error = true; |
| 281 | goto end; |
| 282 | } |
| 283 | |
| 284 | if (num_offset <= 0 || num_offset > LTTNG_KERNEL_MAX_UPROBE_NUM) { |
| 285 | DBG("Wrong number of probes."); |
| 286 | ret = -1; |
| 287 | ret_value->_error = true; |
| 288 | goto free_offset; |
| 289 | } |
| 290 | |
| 291 | /* Copy the content of the offsets array to the ret struct. */ |
| 292 | memcpy(ret_value->u.extract_sdt_probe_offsets.offsets, |
| 293 | offsets, num_offset * sizeof(uint64_t)); |
| 294 | |
| 295 | ret_value->u.extract_sdt_probe_offsets.num_offset = num_offset; |
| 296 | |
| 297 | free_offset: |
| 298 | free(offsets); |
| 299 | end: |
| 300 | return ret; |
| 301 | } |
| 302 | #else |
| 303 | static |
| 304 | int _extract_elf_symbol_offset(struct run_as_data *data, |
| 305 | struct run_as_ret *ret_value) |
| 306 | { |
| 307 | ERR("Unimplemented runas command RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET"); |
| 308 | return -1; |
| 309 | } |
| 310 | |
| 311 | static |
| 312 | int _extract_sdt_probe_offsets(struct run_as_data *data, |
| 313 | struct run_as_ret *ret_value) |
| 314 | { |
| 315 | ERR("Unimplemented runas command RUN_AS_EXTRACT_SDT_PROBE_OFFSETS"); |
| 316 | return -1; |
| 317 | } |
| 318 | #endif |
| 319 | |
| 320 | static |
| 321 | run_as_fct run_as_enum_to_fct(enum run_as_cmd cmd) |
| 322 | { |
| 323 | switch (cmd) { |
| 324 | case RUN_AS_MKDIR: |
| 325 | return _mkdir; |
| 326 | case RUN_AS_OPEN: |
| 327 | return _open; |
| 328 | case RUN_AS_UNLINK: |
| 329 | return _unlink; |
| 330 | case RUN_AS_RMDIR_RECURSIVE: |
| 331 | return _rmdir_recursive; |
| 332 | case RUN_AS_MKDIR_RECURSIVE: |
| 333 | return _mkdir_recursive; |
| 334 | case RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET: |
| 335 | return _extract_elf_symbol_offset; |
| 336 | case RUN_AS_EXTRACT_SDT_PROBE_OFFSETS: |
| 337 | return _extract_sdt_probe_offsets; |
| 338 | default: |
| 339 | ERR("Unknown command %d", (int) cmd); |
| 340 | return NULL; |
| 341 | } |
| 342 | } |
| 343 | |
| 344 | static |
| 345 | int do_send_fd(int sock, int fd) |
| 346 | { |
| 347 | ssize_t len; |
| 348 | |
| 349 | if (fd < 0) { |
| 350 | ERR("Attempt to send invalid file descriptor to master (fd = %i)", fd); |
| 351 | /* Return 0 as this is not a fatal error. */ |
| 352 | return 0; |
| 353 | } |
| 354 | |
| 355 | len = lttcomm_send_fds_unix_sock(sock, &fd, 1); |
| 356 | if (len < 0) { |
| 357 | PERROR("lttcomm_send_fds_unix_sock"); |
| 358 | return -1; |
| 359 | } |
| 360 | return 0; |
| 361 | } |
| 362 | |
| 363 | static |
| 364 | int do_recv_fd(int sock, int *fd) |
| 365 | { |
| 366 | ssize_t len; |
| 367 | |
| 368 | len = lttcomm_recv_fds_unix_sock(sock, fd, 1); |
| 369 | |
| 370 | if (!len) { |
| 371 | return -1; |
| 372 | } else if (len < 0) { |
| 373 | PERROR("lttcomm_recv_fds_unix_sock"); |
| 374 | return -1; |
| 375 | } |
| 376 | if (*fd < 0) { |
| 377 | ERR("Invalid file descriptor received from worker (fd = %i)", *fd); |
| 378 | /* Return 0 as this is not a fatal error. */ |
| 379 | return 0; |
| 380 | } |
| 381 | |
| 382 | return 0; |
| 383 | } |
| 384 | |
| 385 | static |
| 386 | int send_fd_to_worker(struct run_as_worker *worker, enum run_as_cmd cmd, int fd) |
| 387 | { |
| 388 | int ret = 0; |
| 389 | |
| 390 | switch (cmd) { |
| 391 | case RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET: |
| 392 | case RUN_AS_EXTRACT_SDT_PROBE_OFFSETS: |
| 393 | break; |
| 394 | default: |
| 395 | return 0; |
| 396 | } |
| 397 | |
| 398 | if (fd < 0) { |
| 399 | ERR("Refusing to send invalid fd to worker (fd = %i)", fd); |
| 400 | return -1; |
| 401 | } |
| 402 | |
| 403 | ret = do_send_fd(worker->sockpair[0], fd); |
| 404 | if (ret < 0) { |
| 405 | PERROR("do_send_fd"); |
| 406 | ret = -1; |
| 407 | } |
| 408 | |
| 409 | return ret; |
| 410 | } |
| 411 | |
| 412 | static |
| 413 | int send_fd_to_master(struct run_as_worker *worker, enum run_as_cmd cmd, int fd) |
| 414 | { |
| 415 | int ret = 0, ret_close = 0; |
| 416 | |
| 417 | switch (cmd) { |
| 418 | case RUN_AS_OPEN: |
| 419 | break; |
| 420 | default: |
| 421 | return 0; |
| 422 | } |
| 423 | |
| 424 | if (fd < 0) { |
| 425 | DBG("Not sending file descriptor to master as it is invalid (fd = %i)", fd); |
| 426 | return 0; |
| 427 | } |
| 428 | ret = do_send_fd(worker->sockpair[1], fd); |
| 429 | if (ret < 0) { |
| 430 | PERROR("do_send_fd error"); |
| 431 | ret = -1; |
| 432 | } |
| 433 | |
| 434 | ret_close = close(fd); |
| 435 | if (ret_close < 0) { |
| 436 | PERROR("close"); |
| 437 | } |
| 438 | |
| 439 | return ret; |
| 440 | } |
| 441 | |
| 442 | static |
| 443 | int recv_fd_from_worker(struct run_as_worker *worker, enum run_as_cmd cmd, int *fd) |
| 444 | { |
| 445 | int ret = 0; |
| 446 | |
| 447 | switch (cmd) { |
| 448 | case RUN_AS_OPEN: |
| 449 | break; |
| 450 | default: |
| 451 | return 0; |
| 452 | } |
| 453 | |
| 454 | ret = do_recv_fd(worker->sockpair[0], fd); |
| 455 | if (ret < 0) { |
| 456 | PERROR("do_recv_fd error"); |
| 457 | ret = -1; |
| 458 | } |
| 459 | |
| 460 | return ret; |
| 461 | } |
| 462 | |
| 463 | static |
| 464 | int recv_fd_from_master(struct run_as_worker *worker, enum run_as_cmd cmd, int *fd) |
| 465 | { |
| 466 | int ret = 0; |
| 467 | |
| 468 | switch (cmd) { |
| 469 | case RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET: |
| 470 | case RUN_AS_EXTRACT_SDT_PROBE_OFFSETS: |
| 471 | break; |
| 472 | default: |
| 473 | return 0; |
| 474 | } |
| 475 | |
| 476 | ret = do_recv_fd(worker->sockpair[1], fd); |
| 477 | if (ret < 0) { |
| 478 | PERROR("do_recv_fd error"); |
| 479 | ret = -1; |
| 480 | } |
| 481 | |
| 482 | return ret; |
| 483 | } |
| 484 | |
| 485 | static |
| 486 | int cleanup_received_fd(enum run_as_cmd cmd, int fd) |
| 487 | { |
| 488 | int ret = 0; |
| 489 | |
| 490 | switch (cmd) { |
| 491 | case RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET: |
| 492 | case RUN_AS_EXTRACT_SDT_PROBE_OFFSETS: |
| 493 | break; |
| 494 | default: |
| 495 | return 0; |
| 496 | } |
| 497 | |
| 498 | if (fd < 0) { |
| 499 | return 0; |
| 500 | } |
| 501 | ret = close(fd); |
| 502 | if (ret < 0) { |
| 503 | PERROR("close error"); |
| 504 | ret = -1; |
| 505 | } |
| 506 | |
| 507 | return ret; |
| 508 | } |
| 509 | |
| 510 | /* |
| 511 | * Return < 0 on error, 0 if OK, 1 on hangup. |
| 512 | */ |
| 513 | static |
| 514 | int handle_one_cmd(struct run_as_worker *worker) |
| 515 | { |
| 516 | int ret = 0; |
| 517 | struct run_as_data data; |
| 518 | ssize_t readlen, writelen; |
| 519 | struct run_as_ret sendret; |
| 520 | run_as_fct cmd; |
| 521 | uid_t prev_euid; |
| 522 | |
| 523 | memset(&sendret, 0, sizeof(sendret)); |
| 524 | sendret.fd = -1; |
| 525 | |
| 526 | /* |
| 527 | * Stage 1: Receive run_as_data struct from the master. |
| 528 | * The structure contains the command type and all the parameters needed for |
| 529 | * its execution |
| 530 | */ |
| 531 | readlen = lttcomm_recv_unix_sock(worker->sockpair[1], &data, |
| 532 | sizeof(data)); |
| 533 | if (readlen == 0) { |
| 534 | /* hang up */ |
| 535 | ret = 1; |
| 536 | goto end; |
| 537 | } |
| 538 | if (readlen < sizeof(data)) { |
| 539 | PERROR("lttcomm_recv_unix_sock error"); |
| 540 | ret = -1; |
| 541 | goto end; |
| 542 | } |
| 543 | |
| 544 | cmd = run_as_enum_to_fct(data.cmd); |
| 545 | if (!cmd) { |
| 546 | ret = -1; |
| 547 | goto end; |
| 548 | } |
| 549 | |
| 550 | /* |
| 551 | * Stage 2: Receive file descriptor from master. |
| 552 | * Some commands need a file descriptor as input so if it's needed we |
| 553 | * receive the fd using the Unix socket. |
| 554 | */ |
| 555 | ret = recv_fd_from_master(worker, data.cmd, &data.fd); |
| 556 | if (ret < 0) { |
| 557 | PERROR("recv_fd_from_master error"); |
| 558 | ret = -1; |
| 559 | goto end; |
| 560 | } |
| 561 | |
| 562 | prev_euid = getuid(); |
| 563 | if (data.gid != getegid()) { |
| 564 | ret = setegid(data.gid); |
| 565 | if (ret < 0) { |
| 566 | sendret._error = true; |
| 567 | sendret._errno = errno; |
| 568 | PERROR("setegid"); |
| 569 | goto write_return; |
| 570 | } |
| 571 | } |
| 572 | if (data.uid != prev_euid) { |
| 573 | ret = seteuid(data.uid); |
| 574 | if (ret < 0) { |
| 575 | sendret._error = true; |
| 576 | sendret._errno = errno; |
| 577 | PERROR("seteuid"); |
| 578 | goto write_return; |
| 579 | } |
| 580 | } |
| 581 | |
| 582 | /* |
| 583 | * Also set umask to 0 for mkdir executable bit. |
| 584 | */ |
| 585 | umask(0); |
| 586 | |
| 587 | /* |
| 588 | * Stage 3: Execute the command |
| 589 | */ |
| 590 | ret = (*cmd)(&data, &sendret); |
| 591 | if (ret < 0) { |
| 592 | DBG("Execution of command returned an error"); |
| 593 | } |
| 594 | |
| 595 | write_return: |
| 596 | ret = cleanup_received_fd(data.cmd, data.fd); |
| 597 | if (ret < 0) { |
| 598 | ERR("Error cleaning up FD"); |
| 599 | goto end; |
| 600 | } |
| 601 | |
| 602 | /* |
| 603 | * Stage 4: Send run_as_ret structure to the master. |
| 604 | * This structure contain the return value of the command and the errno. |
| 605 | */ |
| 606 | writelen = lttcomm_send_unix_sock(worker->sockpair[1], &sendret, |
| 607 | sizeof(sendret)); |
| 608 | if (writelen < sizeof(sendret)) { |
| 609 | PERROR("lttcomm_send_unix_sock error"); |
| 610 | ret = -1; |
| 611 | goto end; |
| 612 | } |
| 613 | |
| 614 | /* |
| 615 | * Stage 5: Send file descriptor to the master |
| 616 | * Some commands return a file descriptor so if it's needed we pass it back |
| 617 | * to the master using the Unix socket. |
| 618 | */ |
| 619 | ret = send_fd_to_master(worker, data.cmd, sendret.fd); |
| 620 | if (ret < 0) { |
| 621 | DBG("Sending FD to master returned an error"); |
| 622 | goto end; |
| 623 | } |
| 624 | |
| 625 | if (seteuid(prev_euid) < 0) { |
| 626 | PERROR("seteuid"); |
| 627 | ret = -1; |
| 628 | goto end; |
| 629 | } |
| 630 | ret = 0; |
| 631 | end: |
| 632 | return ret; |
| 633 | } |
| 634 | |
| 635 | static |
| 636 | int run_as_worker(struct run_as_worker *worker) |
| 637 | { |
| 638 | int ret; |
| 639 | ssize_t writelen; |
| 640 | struct run_as_ret sendret; |
| 641 | size_t proc_orig_len; |
| 642 | |
| 643 | /* |
| 644 | * Initialize worker. Set a different process cmdline. |
| 645 | */ |
| 646 | proc_orig_len = strlen(worker->procname); |
| 647 | memset(worker->procname, 0, proc_orig_len); |
| 648 | strncpy(worker->procname, DEFAULT_RUN_AS_WORKER_NAME, proc_orig_len); |
| 649 | |
| 650 | ret = lttng_prctl(PR_SET_NAME, |
| 651 | (unsigned long) DEFAULT_RUN_AS_WORKER_NAME, 0, 0, 0); |
| 652 | if (ret && ret != -ENOSYS) { |
| 653 | /* Don't fail as this is not essential. */ |
| 654 | PERROR("prctl PR_SET_NAME"); |
| 655 | } |
| 656 | |
| 657 | memset(&sendret, 0, sizeof(sendret)); |
| 658 | |
| 659 | writelen = lttcomm_send_unix_sock(worker->sockpair[1], &sendret, |
| 660 | sizeof(sendret)); |
| 661 | if (writelen < sizeof(sendret)) { |
| 662 | PERROR("lttcomm_send_unix_sock error"); |
| 663 | ret = EXIT_FAILURE; |
| 664 | goto end; |
| 665 | } |
| 666 | |
| 667 | for (;;) { |
| 668 | ret = handle_one_cmd(worker); |
| 669 | if (ret < 0) { |
| 670 | ret = EXIT_FAILURE; |
| 671 | goto end; |
| 672 | } else if (ret > 0) { |
| 673 | break; |
| 674 | } else { |
| 675 | continue; /* Next command. */ |
| 676 | } |
| 677 | } |
| 678 | ret = EXIT_SUCCESS; |
| 679 | end: |
| 680 | return ret; |
| 681 | } |
| 682 | |
| 683 | static |
| 684 | int run_as_cmd(struct run_as_worker *worker, |
| 685 | enum run_as_cmd cmd, |
| 686 | struct run_as_data *data, |
| 687 | struct run_as_ret *ret_value, |
| 688 | uid_t uid, gid_t gid) |
| 689 | { |
| 690 | int ret = 0; |
| 691 | ssize_t readlen, writelen; |
| 692 | |
| 693 | /* |
| 694 | * If we are non-root, we can only deal with our own uid. |
| 695 | */ |
| 696 | if (geteuid() != 0) { |
| 697 | if (uid != geteuid()) { |
| 698 | ret = -1; |
| 699 | ret_value->_errno = EPERM; |
| 700 | ERR("Client (%d)/Server (%d) UID mismatch (and sessiond is not root)", |
| 701 | (int) uid, (int) geteuid()); |
| 702 | goto end; |
| 703 | } |
| 704 | } |
| 705 | |
| 706 | data->cmd = cmd; |
| 707 | data->uid = uid; |
| 708 | data->gid = gid; |
| 709 | |
| 710 | /* |
| 711 | * Stage 1: Send the run_as_data struct to the worker process |
| 712 | */ |
| 713 | writelen = lttcomm_send_unix_sock(worker->sockpair[0], data, |
| 714 | sizeof(*data)); |
| 715 | if (writelen < sizeof(*data)) { |
| 716 | PERROR("Error writing message to run_as"); |
| 717 | ret = -1; |
| 718 | ret_value->_errno = EIO; |
| 719 | goto end; |
| 720 | } |
| 721 | |
| 722 | /* |
| 723 | * Stage 2: Send file descriptor to the worker process if needed |
| 724 | */ |
| 725 | ret = send_fd_to_worker(worker, data->cmd, data->fd); |
| 726 | if (ret) { |
| 727 | PERROR("do_send_fd error"); |
| 728 | ret = -1; |
| 729 | ret_value->_errno = EIO; |
| 730 | goto end; |
| 731 | } |
| 732 | |
| 733 | /* |
| 734 | * Stage 3: Wait for the execution of the command |
| 735 | */ |
| 736 | |
| 737 | /* |
| 738 | * Stage 4: Receive the run_as_ret struct containing the return value and |
| 739 | * errno |
| 740 | */ |
| 741 | readlen = lttcomm_recv_unix_sock(worker->sockpair[0], ret_value, |
| 742 | sizeof(*ret_value)); |
| 743 | if (!readlen) { |
| 744 | ERR("Run-as worker has hung-up during run_as_cmd"); |
| 745 | ret = -1; |
| 746 | ret_value->_errno = EIO; |
| 747 | goto end; |
| 748 | } else if (readlen < sizeof(*ret_value)) { |
| 749 | PERROR("Error reading response from run_as"); |
| 750 | ret = -1; |
| 751 | ret_value->_errno = errno; |
| 752 | goto end; |
| 753 | } |
| 754 | |
| 755 | if (ret_value->_error) { |
| 756 | /* Skip stage 5 on error as there will be no fd to receive. */ |
| 757 | goto end; |
| 758 | } |
| 759 | |
| 760 | /* |
| 761 | * Stage 5: Receive file descriptor if needed |
| 762 | */ |
| 763 | ret = recv_fd_from_worker(worker, data->cmd, &ret_value->fd); |
| 764 | if (ret < 0) { |
| 765 | ERR("Error receiving fd"); |
| 766 | ret = -1; |
| 767 | ret_value->_errno = EIO; |
| 768 | } |
| 769 | |
| 770 | end: |
| 771 | return ret; |
| 772 | } |
| 773 | |
| 774 | /* |
| 775 | * This is for debugging ONLY and should not be considered secure. |
| 776 | */ |
| 777 | static |
| 778 | int run_as_noworker(enum run_as_cmd cmd, |
| 779 | struct run_as_data *data, struct run_as_ret *ret_value, |
| 780 | uid_t uid, gid_t gid) |
| 781 | { |
| 782 | int ret, saved_errno; |
| 783 | mode_t old_mask; |
| 784 | run_as_fct fct; |
| 785 | |
| 786 | fct = run_as_enum_to_fct(cmd); |
| 787 | if (!fct) { |
| 788 | errno = -ENOSYS; |
| 789 | ret = -1; |
| 790 | goto end; |
| 791 | } |
| 792 | old_mask = umask(0); |
| 793 | ret = fct(data, ret_value); |
| 794 | saved_errno = ret_value->_errno; |
| 795 | umask(old_mask); |
| 796 | errno = saved_errno; |
| 797 | end: |
| 798 | return ret; |
| 799 | } |
| 800 | |
| 801 | static |
| 802 | int reset_sighandler(void) |
| 803 | { |
| 804 | int sig; |
| 805 | |
| 806 | DBG("Resetting run_as worker signal handlers to default"); |
| 807 | for (sig = 1; sig <= 31; sig++) { |
| 808 | (void) signal(sig, SIG_DFL); |
| 809 | } |
| 810 | return 0; |
| 811 | } |
| 812 | |
| 813 | static |
| 814 | void worker_sighandler(int sig) |
| 815 | { |
| 816 | const char *signame; |
| 817 | |
| 818 | /* |
| 819 | * The worker will inherit its parent's signals since they are part of |
| 820 | * the same process group. However, in the case of SIGINT and SIGTERM, |
| 821 | * we want to give the worker a chance to teardown gracefully when its |
| 822 | * parent closes the command socket. |
| 823 | */ |
| 824 | switch (sig) { |
| 825 | case SIGINT: |
| 826 | signame = "SIGINT"; |
| 827 | break; |
| 828 | case SIGTERM: |
| 829 | signame = "SIGTERM"; |
| 830 | break; |
| 831 | default: |
| 832 | signame = NULL; |
| 833 | } |
| 834 | |
| 835 | if (signame) { |
| 836 | DBG("run_as worker received signal %s", signame); |
| 837 | } else { |
| 838 | DBG("run_as_worker received signal %d", sig); |
| 839 | } |
| 840 | } |
| 841 | |
| 842 | static |
| 843 | int set_worker_sighandlers(void) |
| 844 | { |
| 845 | int ret = 0; |
| 846 | sigset_t sigset; |
| 847 | struct sigaction sa; |
| 848 | |
| 849 | if ((ret = sigemptyset(&sigset)) < 0) { |
| 850 | PERROR("sigemptyset"); |
| 851 | goto end; |
| 852 | } |
| 853 | |
| 854 | sa.sa_handler = worker_sighandler; |
| 855 | sa.sa_mask = sigset; |
| 856 | sa.sa_flags = 0; |
| 857 | if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) { |
| 858 | PERROR("sigaction SIGINT"); |
| 859 | goto end; |
| 860 | } |
| 861 | |
| 862 | if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) { |
| 863 | PERROR("sigaction SIGTERM"); |
| 864 | goto end; |
| 865 | } |
| 866 | |
| 867 | DBG("run_as signal handler set for SIGTERM and SIGINT"); |
| 868 | end: |
| 869 | return ret; |
| 870 | } |
| 871 | |
| 872 | static |
| 873 | int run_as_create_worker_no_lock(const char *procname, |
| 874 | post_fork_cleanup_cb clean_up_func, |
| 875 | void *clean_up_user_data) |
| 876 | { |
| 877 | pid_t pid; |
| 878 | int i, ret = 0; |
| 879 | ssize_t readlen; |
| 880 | struct run_as_ret recvret; |
| 881 | struct run_as_worker *worker; |
| 882 | |
| 883 | assert(!global_worker); |
| 884 | if (!use_clone()) { |
| 885 | /* |
| 886 | * Don't initialize a worker, all run_as tasks will be performed |
| 887 | * in the current process. |
| 888 | */ |
| 889 | ret = 0; |
| 890 | goto end; |
| 891 | } |
| 892 | worker = zmalloc(sizeof(*worker)); |
| 893 | if (!worker) { |
| 894 | ret = -ENOMEM; |
| 895 | goto end; |
| 896 | } |
| 897 | worker->procname = strdup(procname); |
| 898 | if (!worker->procname) { |
| 899 | ret = -ENOMEM; |
| 900 | goto error_procname_alloc; |
| 901 | } |
| 902 | /* Create unix socket. */ |
| 903 | if (lttcomm_create_anon_unix_socketpair(worker->sockpair) < 0) { |
| 904 | ret = -1; |
| 905 | goto error_sock; |
| 906 | } |
| 907 | |
| 908 | /* Fork worker. */ |
| 909 | pid = fork(); |
| 910 | if (pid < 0) { |
| 911 | PERROR("fork"); |
| 912 | ret = -1; |
| 913 | goto error_fork; |
| 914 | } else if (pid == 0) { |
| 915 | /* Child */ |
| 916 | |
| 917 | reset_sighandler(); |
| 918 | |
| 919 | set_worker_sighandlers(); |
| 920 | if (clean_up_func) { |
| 921 | if (clean_up_func(clean_up_user_data) < 0) { |
| 922 | ERR("Run-as post-fork clean-up failed, exiting."); |
| 923 | exit(EXIT_FAILURE); |
| 924 | } |
| 925 | } |
| 926 | |
| 927 | /* Just close, no shutdown. */ |
| 928 | if (close(worker->sockpair[0])) { |
| 929 | PERROR("close"); |
| 930 | exit(EXIT_FAILURE); |
| 931 | } |
| 932 | |
| 933 | /* |
| 934 | * Close all FDs aside from STDIN, STDOUT, STDERR and sockpair[1] |
| 935 | * Sockpair[1] is used as a control channel with the master |
| 936 | */ |
| 937 | for (i = 3; i < sysconf(_SC_OPEN_MAX); i++) { |
| 938 | if (i != worker->sockpair[1]) { |
| 939 | (void) close(i); |
| 940 | } |
| 941 | } |
| 942 | |
| 943 | worker->sockpair[0] = -1; |
| 944 | ret = run_as_worker(worker); |
| 945 | if (lttcomm_close_unix_sock(worker->sockpair[1])) { |
| 946 | PERROR("close"); |
| 947 | ret = -1; |
| 948 | } |
| 949 | worker->sockpair[1] = -1; |
| 950 | free(worker->procname); |
| 951 | free(worker); |
| 952 | LOG(ret ? PRINT_ERR : PRINT_DBG, "run_as worker exiting (ret = %d)", ret); |
| 953 | exit(ret ? EXIT_FAILURE : EXIT_SUCCESS); |
| 954 | } else { |
| 955 | /* Parent */ |
| 956 | |
| 957 | /* Just close, no shutdown. */ |
| 958 | if (close(worker->sockpair[1])) { |
| 959 | PERROR("close"); |
| 960 | ret = -1; |
| 961 | goto error_fork; |
| 962 | } |
| 963 | worker->sockpair[1] = -1; |
| 964 | worker->pid = pid; |
| 965 | /* Wait for worker to become ready. */ |
| 966 | readlen = lttcomm_recv_unix_sock(worker->sockpair[0], |
| 967 | &recvret, sizeof(recvret)); |
| 968 | if (readlen < sizeof(recvret)) { |
| 969 | ERR("readlen: %zd", readlen); |
| 970 | PERROR("Error reading response from run_as at creation"); |
| 971 | ret = -1; |
| 972 | goto error_fork; |
| 973 | } |
| 974 | global_worker = worker; |
| 975 | } |
| 976 | end: |
| 977 | return ret; |
| 978 | |
| 979 | /* Error handling. */ |
| 980 | error_fork: |
| 981 | for (i = 0; i < 2; i++) { |
| 982 | if (worker->sockpair[i] < 0) { |
| 983 | continue; |
| 984 | } |
| 985 | if (lttcomm_close_unix_sock(worker->sockpair[i])) { |
| 986 | PERROR("close"); |
| 987 | } |
| 988 | worker->sockpair[i] = -1; |
| 989 | } |
| 990 | error_sock: |
| 991 | free(worker->procname); |
| 992 | error_procname_alloc: |
| 993 | free(worker); |
| 994 | return ret; |
| 995 | } |
| 996 | |
| 997 | static |
| 998 | void run_as_destroy_worker_no_lock(void) |
| 999 | { |
| 1000 | struct run_as_worker *worker = global_worker; |
| 1001 | |
| 1002 | DBG("Destroying run_as worker"); |
| 1003 | if (!worker) { |
| 1004 | return; |
| 1005 | } |
| 1006 | /* Close unix socket */ |
| 1007 | DBG("Closing run_as worker socket"); |
| 1008 | if (lttcomm_close_unix_sock(worker->sockpair[0])) { |
| 1009 | PERROR("close"); |
| 1010 | } |
| 1011 | worker->sockpair[0] = -1; |
| 1012 | /* Wait for worker. */ |
| 1013 | for (;;) { |
| 1014 | int status; |
| 1015 | pid_t wait_ret; |
| 1016 | |
| 1017 | wait_ret = waitpid(worker->pid, &status, 0); |
| 1018 | if (wait_ret < 0) { |
| 1019 | if (errno == EINTR) { |
| 1020 | continue; |
| 1021 | } |
| 1022 | PERROR("waitpid"); |
| 1023 | break; |
| 1024 | } |
| 1025 | |
| 1026 | if (WIFEXITED(status)) { |
| 1027 | LOG(WEXITSTATUS(status) == 0 ? PRINT_DBG : PRINT_ERR, |
| 1028 | DEFAULT_RUN_AS_WORKER_NAME " terminated with status code %d", |
| 1029 | WEXITSTATUS(status)); |
| 1030 | break; |
| 1031 | } else if (WIFSIGNALED(status)) { |
| 1032 | ERR(DEFAULT_RUN_AS_WORKER_NAME " was killed by signal %d", |
| 1033 | WTERMSIG(status)); |
| 1034 | break; |
| 1035 | } |
| 1036 | } |
| 1037 | free(worker->procname); |
| 1038 | free(worker); |
| 1039 | global_worker = NULL; |
| 1040 | } |
| 1041 | |
| 1042 | static |
| 1043 | int run_as_restart_worker(struct run_as_worker *worker) |
| 1044 | { |
| 1045 | int ret = 0; |
| 1046 | char *procname = NULL; |
| 1047 | |
| 1048 | procname = worker->procname; |
| 1049 | |
| 1050 | /* Close socket to run_as worker process and clean up the zombie process */ |
| 1051 | run_as_destroy_worker_no_lock(); |
| 1052 | |
| 1053 | /* Create a new run_as worker process*/ |
| 1054 | ret = run_as_create_worker_no_lock(procname, NULL, NULL); |
| 1055 | if (ret < 0 ) { |
| 1056 | ERR("Restarting the worker process failed"); |
| 1057 | ret = -1; |
| 1058 | goto err; |
| 1059 | } |
| 1060 | err: |
| 1061 | return ret; |
| 1062 | } |
| 1063 | |
| 1064 | static |
| 1065 | int run_as(enum run_as_cmd cmd, struct run_as_data *data, |
| 1066 | struct run_as_ret *ret_value, uid_t uid, gid_t gid) |
| 1067 | { |
| 1068 | int ret, saved_errno; |
| 1069 | |
| 1070 | pthread_mutex_lock(&worker_lock); |
| 1071 | if (use_clone()) { |
| 1072 | DBG("Using run_as worker"); |
| 1073 | |
| 1074 | assert(global_worker); |
| 1075 | |
| 1076 | ret = run_as_cmd(global_worker, cmd, data, ret_value, uid, gid); |
| 1077 | saved_errno = ret_value->_errno; |
| 1078 | |
| 1079 | /* |
| 1080 | * If the worker thread crashed the errno is set to EIO. we log |
| 1081 | * the error and start a new worker process. |
| 1082 | */ |
| 1083 | if (ret == -1 && saved_errno == EIO) { |
| 1084 | DBG("Socket closed unexpectedly... " |
| 1085 | "Restarting the worker process"); |
| 1086 | ret = run_as_restart_worker(global_worker); |
| 1087 | if (ret == -1) { |
| 1088 | ERR("Failed to restart worker process."); |
| 1089 | goto err; |
| 1090 | } |
| 1091 | } |
| 1092 | } else { |
| 1093 | DBG("Using run_as without worker"); |
| 1094 | ret = run_as_noworker(cmd, data, ret_value, uid, gid); |
| 1095 | } |
| 1096 | err: |
| 1097 | pthread_mutex_unlock(&worker_lock); |
| 1098 | return ret; |
| 1099 | } |
| 1100 | |
| 1101 | LTTNG_HIDDEN |
| 1102 | int run_as_mkdir_recursive(const char *path, mode_t mode, uid_t uid, gid_t gid) |
| 1103 | { |
| 1104 | struct run_as_data data; |
| 1105 | struct run_as_ret ret; |
| 1106 | |
| 1107 | memset(&data, 0, sizeof(data)); |
| 1108 | memset(&ret, 0, sizeof(ret)); |
| 1109 | DBG3("mkdir() recursive %s with mode %d for uid %d and gid %d", |
| 1110 | path, (int) mode, (int) uid, (int) gid); |
| 1111 | strncpy(data.u.mkdir.path, path, PATH_MAX - 1); |
| 1112 | data.u.mkdir.path[PATH_MAX - 1] = '\0'; |
| 1113 | data.u.mkdir.mode = mode; |
| 1114 | |
| 1115 | run_as(RUN_AS_MKDIR_RECURSIVE, &data, &ret, uid, gid); |
| 1116 | errno = ret._errno; |
| 1117 | return ret.u.mkdir.ret; |
| 1118 | } |
| 1119 | |
| 1120 | LTTNG_HIDDEN |
| 1121 | int run_as_mkdir(const char *path, mode_t mode, uid_t uid, gid_t gid) |
| 1122 | { |
| 1123 | struct run_as_data data; |
| 1124 | struct run_as_ret ret; |
| 1125 | |
| 1126 | memset(&data, 0, sizeof(data)); |
| 1127 | memset(&ret, 0, sizeof(ret)); |
| 1128 | |
| 1129 | DBG3("mkdir() %s with mode %d for uid %d and gid %d", |
| 1130 | path, (int) mode, (int) uid, (int) gid); |
| 1131 | strncpy(data.u.mkdir.path, path, PATH_MAX - 1); |
| 1132 | data.u.mkdir.path[PATH_MAX - 1] = '\0'; |
| 1133 | data.u.mkdir.mode = mode; |
| 1134 | run_as(RUN_AS_MKDIR, &data, &ret, uid, gid); |
| 1135 | errno = ret._errno; |
| 1136 | return ret.u.mkdir.ret; |
| 1137 | } |
| 1138 | |
| 1139 | LTTNG_HIDDEN |
| 1140 | int run_as_open(const char *path, int flags, mode_t mode, uid_t uid, gid_t gid) |
| 1141 | { |
| 1142 | struct run_as_data data; |
| 1143 | struct run_as_ret ret; |
| 1144 | |
| 1145 | memset(&data, 0, sizeof(data)); |
| 1146 | memset(&ret, 0, sizeof(ret)); |
| 1147 | |
| 1148 | DBG3("open() %s with flags %X mode %d for uid %d and gid %d", |
| 1149 | path, flags, (int) mode, (int) uid, (int) gid); |
| 1150 | strncpy(data.u.open.path, path, PATH_MAX - 1); |
| 1151 | data.u.open.path[PATH_MAX - 1] = '\0'; |
| 1152 | data.u.open.flags = flags; |
| 1153 | data.u.open.mode = mode; |
| 1154 | run_as(RUN_AS_OPEN, &data, &ret, uid, gid); |
| 1155 | errno = ret._errno; |
| 1156 | ret.u.open.ret = ret.fd; |
| 1157 | return ret.u.open.ret; |
| 1158 | } |
| 1159 | |
| 1160 | LTTNG_HIDDEN |
| 1161 | int run_as_unlink(const char *path, uid_t uid, gid_t gid) |
| 1162 | { |
| 1163 | struct run_as_data data; |
| 1164 | struct run_as_ret ret; |
| 1165 | |
| 1166 | memset(&data, 0, sizeof(data)); |
| 1167 | memset(&ret, 0, sizeof(ret)); |
| 1168 | |
| 1169 | DBG3("unlink() %s with for uid %d and gid %d", |
| 1170 | path, (int) uid, (int) gid); |
| 1171 | strncpy(data.u.unlink.path, path, PATH_MAX - 1); |
| 1172 | data.u.unlink.path[PATH_MAX - 1] = '\0'; |
| 1173 | run_as(RUN_AS_UNLINK, &data, &ret, uid, gid); |
| 1174 | errno = ret._errno; |
| 1175 | return ret.u.unlink.ret; |
| 1176 | } |
| 1177 | |
| 1178 | LTTNG_HIDDEN |
| 1179 | int run_as_rmdir_recursive(const char *path, uid_t uid, gid_t gid) |
| 1180 | { |
| 1181 | struct run_as_data data; |
| 1182 | struct run_as_ret ret; |
| 1183 | |
| 1184 | memset(&data, 0, sizeof(data)); |
| 1185 | memset(&ret, 0, sizeof(ret)); |
| 1186 | |
| 1187 | DBG3("rmdir_recursive() %s with for uid %d and gid %d", |
| 1188 | path, (int) uid, (int) gid); |
| 1189 | strncpy(data.u.rmdir_recursive.path, path, PATH_MAX - 1); |
| 1190 | data.u.rmdir_recursive.path[PATH_MAX - 1] = '\0'; |
| 1191 | run_as(RUN_AS_RMDIR_RECURSIVE, &data, &ret, uid, gid); |
| 1192 | errno = ret._errno; |
| 1193 | return ret.u.rmdir_recursive.ret; |
| 1194 | } |
| 1195 | |
| 1196 | LTTNG_HIDDEN |
| 1197 | int run_as_extract_elf_symbol_offset(int fd, const char* function, |
| 1198 | uid_t uid, gid_t gid, uint64_t *offset) |
| 1199 | { |
| 1200 | struct run_as_data data; |
| 1201 | struct run_as_ret ret; |
| 1202 | |
| 1203 | memset(&data, 0, sizeof(data)); |
| 1204 | memset(&ret, 0, sizeof(ret)); |
| 1205 | |
| 1206 | DBG3("extract_elf_symbol_offset() on fd=%d and function=%s " |
| 1207 | "with for uid %d and gid %d", fd, function, (int) uid, (int) gid); |
| 1208 | |
| 1209 | data.fd = fd; |
| 1210 | |
| 1211 | strncpy(data.u.extract_elf_symbol_offset.function, function, LTTNG_SYMBOL_NAME_LEN - 1); |
| 1212 | |
| 1213 | data.u.extract_elf_symbol_offset.function[LTTNG_SYMBOL_NAME_LEN - 1] = '\0'; |
| 1214 | |
| 1215 | run_as(RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET, &data, &ret, uid, gid); |
| 1216 | |
| 1217 | errno = ret._errno; |
| 1218 | |
| 1219 | if (ret._error) { |
| 1220 | return -1; |
| 1221 | } |
| 1222 | |
| 1223 | *offset = ret.u.extract_elf_symbol_offset.offset; |
| 1224 | return 0; |
| 1225 | } |
| 1226 | |
| 1227 | LTTNG_HIDDEN |
| 1228 | int run_as_extract_sdt_probe_offsets(int fd, const char* provider_name, |
| 1229 | const char* probe_name, uid_t uid, gid_t gid, |
| 1230 | uint64_t **offsets, uint32_t *num_offset) |
| 1231 | { |
| 1232 | struct run_as_data data; |
| 1233 | struct run_as_ret ret; |
| 1234 | |
| 1235 | memset(&data, 0, sizeof(data)); |
| 1236 | memset(&ret, 0, sizeof(ret)); |
| 1237 | |
| 1238 | DBG3("extract_sdt_probe_offsets() on fd=%d, probe_name=%s and " |
| 1239 | "provider_name=%s with for uid %d and gid %d", fd, probe_name, |
| 1240 | provider_name, (int) uid, (int) gid); |
| 1241 | |
| 1242 | data.fd = fd; |
| 1243 | |
| 1244 | strncpy(data.u.extract_sdt_probe_offsets.probe_name, probe_name, LTTNG_SYMBOL_NAME_LEN - 1); |
| 1245 | strncpy(data.u.extract_sdt_probe_offsets.provider_name, provider_name, LTTNG_SYMBOL_NAME_LEN - 1); |
| 1246 | |
| 1247 | data.u.extract_sdt_probe_offsets.probe_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0'; |
| 1248 | data.u.extract_sdt_probe_offsets.provider_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0'; |
| 1249 | |
| 1250 | run_as(RUN_AS_EXTRACT_SDT_PROBE_OFFSETS, &data, &ret, uid, gid); |
| 1251 | |
| 1252 | errno = ret._errno; |
| 1253 | |
| 1254 | if (ret._error) { |
| 1255 | return -1; |
| 1256 | } |
| 1257 | |
| 1258 | *num_offset = ret.u.extract_sdt_probe_offsets.num_offset; |
| 1259 | |
| 1260 | *offsets = zmalloc(*num_offset * sizeof(uint64_t)); |
| 1261 | if (!*offsets) { |
| 1262 | return -ENOMEM; |
| 1263 | } |
| 1264 | |
| 1265 | memcpy(*offsets, ret.u.extract_sdt_probe_offsets.offsets, *num_offset * sizeof(uint64_t)); |
| 1266 | return 0; |
| 1267 | } |
| 1268 | |
| 1269 | LTTNG_HIDDEN |
| 1270 | int run_as_create_worker(const char *procname, |
| 1271 | post_fork_cleanup_cb clean_up_func, |
| 1272 | void *clean_up_user_data) |
| 1273 | { |
| 1274 | int ret; |
| 1275 | |
| 1276 | pthread_mutex_lock(&worker_lock); |
| 1277 | ret = run_as_create_worker_no_lock(procname, clean_up_func, |
| 1278 | clean_up_user_data); |
| 1279 | pthread_mutex_unlock(&worker_lock); |
| 1280 | return ret; |
| 1281 | } |
| 1282 | |
| 1283 | LTTNG_HIDDEN |
| 1284 | void run_as_destroy_worker(void) |
| 1285 | { |
| 1286 | pthread_mutex_lock(&worker_lock); |
| 1287 | run_as_destroy_worker_no_lock(); |
| 1288 | pthread_mutex_unlock(&worker_lock); |
| 1289 | } |