src/common/runas.c

   1 /*
   2  * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
   3  * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  * Copyright (C) 2019 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   5  *
   6  * SPDX-License-Identifier: GPL-2.0-only
   7  *
   8  */
   9
  10 #define _LGPL_SOURCE
  11 #include <errno.h>
  12 #include <limits.h>
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <string.h>
  16 #include <sys/wait.h>
  17 #include <sys/types.h>
  18 #include <sys/stat.h>
  19 #include <unistd.h>
  20 #include <fcntl.h>
  21 #include <sched.h>
  22 #include <signal.h>
  23 #include <assert.h>
  24 #include <signal.h>
  25
  26 #include <common/lttng-kernel.h>
  27 #include <common/common.h>
  28 #include <common/utils.h>
  29 #include <common/compat/getenv.h>
  30 #include <common/unix.h>
  31 #include <common/defaults.h>
  32 #include <common/lttng-elf.h>
  33 #include <common/thread.h>
  34
  35 #include <lttng/constant.h>
  36
  37 #include "runas.h"
  38
  39 struct run_as_data;
  40 struct run_as_ret;
  41 typedef int (*run_as_fct)(struct run_as_data *data, struct run_as_ret *ret_value);
  42
  43 enum run_as_cmd {
  44         RUN_AS_MKDIR,
  45         RUN_AS_MKDIRAT,
  46         RUN_AS_MKDIR_RECURSIVE,
  47         RUN_AS_MKDIRAT_RECURSIVE,
  48         RUN_AS_OPEN,
  49         RUN_AS_OPENAT,
  50         RUN_AS_UNLINK,
  51         RUN_AS_UNLINKAT,
  52         RUN_AS_RMDIR,
  53         RUN_AS_RMDIRAT,
  54         RUN_AS_RMDIR_RECURSIVE,
  55         RUN_AS_RMDIRAT_RECURSIVE,
  56         RUN_AS_RENAME,
  57         RUN_AS_RENAMEAT,
  58         RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET,
  59         RUN_AS_EXTRACT_SDT_PROBE_OFFSETS,
  60 };
  61
  62 struct run_as_mkdir_data {
  63         int dirfd;
  64         char path[LTTNG_PATH_MAX];
  65         mode_t mode;
  66 } LTTNG_PACKED;
  67
  68 struct run_as_open_data {
  69         int dirfd;
  70         char path[LTTNG_PATH_MAX];
  71         int flags;
  72         mode_t mode;
  73 } LTTNG_PACKED;
  74
  75 struct run_as_unlink_data {
  76         int dirfd;
  77         char path[LTTNG_PATH_MAX];
  78 } LTTNG_PACKED;
  79
  80 struct run_as_rmdir_data {
  81         int dirfd;
  82         char path[LTTNG_PATH_MAX];
  83         int flags; /* enum lttng_directory_handle_rmdir_recursive_flags */
  84 } LTTNG_PACKED;
  85
  86 struct run_as_extract_elf_symbol_offset_data {
  87         int fd;
  88         char function[LTTNG_SYMBOL_NAME_LEN];
  89 } LTTNG_PACKED;
  90
  91 struct run_as_extract_sdt_probe_offsets_data {
  92         int fd;
  93         char probe_name[LTTNG_SYMBOL_NAME_LEN];
  94         char provider_name[LTTNG_SYMBOL_NAME_LEN];
  95 } LTTNG_PACKED;
  96
  97 struct run_as_rename_data {
  98         /*
  99          * [0] = old_dirfd
 100          * [1] = new_dirfd
 101          */
 102         int dirfds[2];
 103         char old_path[LTTNG_PATH_MAX];
 104         char new_path[LTTNG_PATH_MAX];
 105 } LTTNG_PACKED;
 106
 107 struct run_as_open_ret {
 108         int fd;
 109 } LTTNG_PACKED;
 110
 111 struct run_as_extract_elf_symbol_offset_ret {
 112         uint64_t offset;
 113 } LTTNG_PACKED;
 114
 115 struct run_as_extract_sdt_probe_offsets_ret {
 116         uint32_t num_offset;
 117         uint64_t offsets[LTTNG_KERNEL_MAX_UPROBE_NUM];
 118 } LTTNG_PACKED;
 119
 120 struct run_as_data {
 121         enum run_as_cmd cmd;
 122         union {
 123                 struct run_as_mkdir_data mkdir;
 124                 struct run_as_open_data open;
 125                 struct run_as_unlink_data unlink;
 126                 struct run_as_rmdir_data rmdir;
 127                 struct run_as_rename_data rename;
 128                 struct run_as_extract_elf_symbol_offset_data extract_elf_symbol_offset;
 129                 struct run_as_extract_sdt_probe_offsets_data extract_sdt_probe_offsets;
 130         } u;
 131         uid_t uid;
 132         gid_t gid;
 133 } LTTNG_PACKED;
 134
 135 /*
 136  * The run_as_ret structure holds the returned value and status of the command.
 137  *
 138  * The `u` union field holds the return value of the command; in most cases it
 139  * represents the success or the failure of the command. In more complex
 140  * commands, it holds a computed value.
 141  *
 142  * The _errno field is the errno recorded after the execution of the command.
 143  *
 144  * The _error fields is used the signify that return status of the command. For
 145  * simple commands returning `int` the _error field will be the same as the
 146  * ret_int field. In complex commands, it signify the success or failure of the
 147  * command.
 148  *
 149  */
 150 struct run_as_ret {
 151         union {
 152                 int ret;
 153                 struct run_as_open_ret open;
 154                 struct run_as_extract_elf_symbol_offset_ret extract_elf_symbol_offset;
 155                 struct run_as_extract_sdt_probe_offsets_ret extract_sdt_probe_offsets;
 156         } u;
 157         int _errno;
 158         bool _error;
 159 } LTTNG_PACKED;
 160
 161 #define COMMAND_IN_FDS(data_ptr) ({                                     \
 162         int *fds = NULL;                                                \
 163         if (command_properties[data_ptr->cmd].in_fds_offset != -1) {    \
 164                 fds = (int *) ((char *) data_ptr + command_properties[data_ptr->cmd].in_fds_offset); \
 165         }                                                               \
 166         fds;                                                            \
 167 })
 168
 169 #define COMMAND_OUT_FDS(cmd, ret_ptr) ({                                \
 170         int *fds = NULL;                                                \
 171         if (command_properties[cmd].out_fds_offset != -1) {             \
 172                 fds = (int *) ((char *) ret_ptr + command_properties[cmd].out_fds_offset); \
 173         }                                                               \
 174         fds;                                                            \
 175 })
 176
 177 #define COMMAND_IN_FD_COUNT(data_ptr) ({                \
 178         command_properties[data_ptr->cmd].in_fd_count;  \
 179 })
 180
 181 #define COMMAND_OUT_FD_COUNT(cmd) ({            \
 182         command_properties[cmd].out_fd_count;   \
 183 })
 184
 185 #define COMMAND_USE_CWD_FD(data_ptr) command_properties[data_ptr->cmd].use_cwd_fd
 186
 187 struct run_as_command_properties {
 188         /* Set to -1 when not applicable. */
 189         ptrdiff_t in_fds_offset, out_fds_offset;
 190         unsigned int in_fd_count, out_fd_count;
 191         bool use_cwd_fd;
 192 };
 193
 194 static const struct run_as_command_properties command_properties[] = {
 195         [RUN_AS_MKDIR] = {
 196                 .in_fds_offset = offsetof(struct run_as_data, u.mkdir.dirfd),
 197                 .in_fd_count = 1,
 198                 .out_fds_offset = -1,
 199                 .out_fd_count = 0,
 200                 .use_cwd_fd = true,
 201         },
 202         [RUN_AS_MKDIRAT] = {
 203                 .in_fds_offset = offsetof(struct run_as_data, u.mkdir.dirfd),
 204                 .in_fd_count = 1,
 205                 .out_fds_offset = -1,
 206                 .out_fd_count = 0,
 207                 .use_cwd_fd = false,
 208         },
 209         [RUN_AS_MKDIR_RECURSIVE] = {
 210                 .in_fds_offset = offsetof(struct run_as_data, u.mkdir.dirfd),
 211                 .in_fd_count = 1,
 212                 .out_fds_offset = -1,
 213                 .out_fd_count = 0,
 214                 .use_cwd_fd = true,
 215         },
 216         [RUN_AS_MKDIRAT_RECURSIVE] = {
 217                 .in_fds_offset = offsetof(struct run_as_data, u.mkdir.dirfd),
 218                 .in_fd_count = 1,
 219                 .out_fds_offset = -1,
 220                 .out_fd_count = 0,
 221                 .use_cwd_fd = false,
 222         },
 223         [RUN_AS_OPEN] = {
 224                 .in_fds_offset = offsetof(struct run_as_data, u.open.dirfd),
 225                 .in_fd_count = 1,
 226                 .out_fds_offset = offsetof(struct run_as_ret, u.open.fd),
 227                 .out_fd_count = 1,
 228                 .use_cwd_fd = true,
 229         },
 230         [RUN_AS_OPENAT] = {
 231                 .in_fds_offset = offsetof(struct run_as_data, u.open.dirfd),
 232                 .in_fd_count = 1,
 233                 .out_fds_offset = offsetof(struct run_as_ret, u.open.fd),
 234                 .out_fd_count = 1,
 235                 .use_cwd_fd = false,
 236         },
 237         [RUN_AS_UNLINK] = {
 238                 .in_fds_offset = offsetof(struct run_as_data, u.unlink.dirfd),
 239                 .in_fd_count = 1,
 240                 .out_fds_offset = -1,
 241                 .out_fd_count = 0,
 242                 .use_cwd_fd = true,
 243         },
 244         [RUN_AS_UNLINKAT] = {
 245                 .in_fds_offset = offsetof(struct run_as_data, u.unlink.dirfd),
 246                 .in_fd_count = 1,
 247                 .out_fds_offset = -1,
 248                 .out_fd_count = 0,
 249                 .use_cwd_fd = false,
 250         },
 251         [RUN_AS_RMDIR_RECURSIVE] = {
 252                 .in_fds_offset = offsetof(struct run_as_data, u.rmdir.dirfd),
 253                 .in_fd_count = 1,
 254                 .out_fds_offset = -1,
 255                 .out_fd_count = 0,
 256                 .use_cwd_fd = true,
 257         },
 258         [RUN_AS_RMDIRAT_RECURSIVE] = {
 259                 .in_fds_offset = offsetof(struct run_as_data, u.rmdir.dirfd),
 260                 .in_fd_count = 1,
 261                 .out_fds_offset = -1,
 262                 .out_fd_count = 0,
 263                 .use_cwd_fd = false,
 264         },
 265         [RUN_AS_RMDIR] = {
 266                 .in_fds_offset = offsetof(struct run_as_data, u.rmdir.dirfd),
 267                 .in_fd_count = 1,
 268                 .out_fds_offset = -1,
 269                 .out_fd_count = 0,
 270                 .use_cwd_fd = true,
 271         },
 272         [RUN_AS_RMDIRAT] = {
 273                 .in_fds_offset = offsetof(struct run_as_data, u.rmdir.dirfd),
 274                 .in_fd_count = 1,
 275                 .out_fds_offset = -1,
 276                 .out_fd_count = 0,
 277                 .use_cwd_fd = false,
 278         },
 279         [RUN_AS_RENAME] = {
 280                 .in_fds_offset = offsetof(struct run_as_data, u.rename.dirfds),
 281                 .in_fd_count = 2,
 282                 .out_fds_offset = -1,
 283                 .out_fd_count = 0,
 284                 .use_cwd_fd = true,
 285         },
 286         [RUN_AS_RENAMEAT] = {
 287                 .in_fds_offset = offsetof(struct run_as_data, u.rename.dirfds),
 288                 .in_fd_count = 2,
 289                 .out_fds_offset = -1,
 290                 .out_fd_count = 0,
 291                 .use_cwd_fd = false,
 292         },
 293         [RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET] = {
 294                 .in_fds_offset = offsetof(struct run_as_data,
 295                                 u.extract_elf_symbol_offset.fd),
 296                 .in_fd_count = 1,
 297                 .out_fds_offset = -1,
 298                 .out_fd_count = 0,
 299                 .use_cwd_fd = false,
 300         },
 301         [RUN_AS_EXTRACT_SDT_PROBE_OFFSETS] = {
 302                 .in_fds_offset = offsetof(struct run_as_data,
 303                                 u.extract_sdt_probe_offsets.fd),
 304                 .in_fd_count = 1,
 305                 .out_fds_offset = -1,
 306                 .out_fd_count = 0,
 307                 .use_cwd_fd = false,
 308         },
 309 };
 310
 311 struct run_as_worker {
 312         pid_t pid;      /* Worker PID. */
 313         int sockpair[2];
 314         char *procname;
 315 };
 316
 317 /* Single global worker per process (for now). */
 318 static struct run_as_worker *global_worker;
 319 /* Lock protecting the worker. */
 320 static pthread_mutex_t worker_lock = PTHREAD_MUTEX_INITIALIZER;
 321
 322 #ifdef VALGRIND
 323 static
 324 int use_clone(void)
 325 {
 326         return 0;
 327 }
 328 #else
 329 static
 330 int use_clone(void)
 331 {
 332         return !lttng_secure_getenv("LTTNG_DEBUG_NOCLONE");
 333 }
 334 #endif
 335
 336 /*
 337  * Create recursively directory using the FULL path.
 338  */
 339 static
 340 int _mkdirat_recursive(struct run_as_data *data, struct run_as_ret *ret_value)
 341 {
 342         const char *path;
 343         mode_t mode;
 344         struct lttng_directory_handle *handle;
 345
 346         path = data->u.mkdir.path;
 347         mode = data->u.mkdir.mode;
 348
 349         handle = lttng_directory_handle_create_from_dirfd(data->u.mkdir.dirfd);
 350         if (!handle) {
 351                 ret_value->_errno = errno;
 352                 ret_value->_error = true;
 353                 ret_value->u.ret = -1;
 354                 goto end;
 355         }
 356         /* Ownership of dirfd is transferred to the handle. */
 357         data->u.mkdir.dirfd = -1;
 358         /* Safe to call as we have transitioned to the requested uid/gid. */
 359         ret_value->u.ret = lttng_directory_handle_create_subdirectory_recursive(
 360                         handle, path, mode);
 361         ret_value->_errno = errno;
 362         ret_value->_error = (ret_value->u.ret) ? true : false;
 363         lttng_directory_handle_put(handle);
 364 end:
 365         return ret_value->u.ret;
 366 }
 367
 368 static
 369 int _mkdirat(struct run_as_data *data, struct run_as_ret *ret_value)
 370 {
 371         const char *path;
 372         mode_t mode;
 373         struct lttng_directory_handle *handle;
 374
 375         path = data->u.mkdir.path;
 376         mode = data->u.mkdir.mode;
 377
 378         handle = lttng_directory_handle_create_from_dirfd(data->u.mkdir.dirfd);
 379         if (!handle) {
 380                 ret_value->u.ret = -1;
 381                 ret_value->_errno = errno;
 382                 ret_value->_error = true;
 383                 goto end;
 384         }
 385         /* Ownership of dirfd is transferred to the handle. */
 386         data->u.mkdir.dirfd = -1;
 387         /* Safe to call as we have transitioned to the requested uid/gid. */
 388         ret_value->u.ret = lttng_directory_handle_create_subdirectory(
 389                         handle, path, mode);
 390         ret_value->_errno = errno;
 391         ret_value->_error = (ret_value->u.ret) ? true : false;
 392         lttng_directory_handle_put(handle);
 393 end:
 394         return ret_value->u.ret;
 395 }
 396
 397 static
 398 int _open(struct run_as_data *data, struct run_as_ret *ret_value)
 399 {
 400         int fd;
 401         struct lttng_directory_handle *handle;
 402
 403         handle = lttng_directory_handle_create_from_dirfd(data->u.open.dirfd);
 404         if (!handle) {
 405                 ret_value->_errno = errno;
 406                 ret_value->_error = true;
 407                 ret_value->u.ret = -1;
 408                 goto end;
 409         }
 410         /* Ownership of dirfd is transferred to the handle. */
 411         data->u.open.dirfd = -1;
 412
 413         fd = lttng_directory_handle_open_file(handle,
 414                         data->u.open.path, data->u.open.flags,
 415                         data->u.open.mode);
 416         if (fd < 0) {
 417                 ret_value->u.ret = -1;
 418                 ret_value->u.open.fd = -1;
 419         } else {
 420                 ret_value->u.ret = 0;
 421                 ret_value->u.open.fd = fd;
 422         }
 423
 424         ret_value->_errno = errno;
 425         ret_value->_error = fd < 0;
 426         lttng_directory_handle_put(handle);
 427 end:
 428         return ret_value->u.ret;
 429 }
 430
 431 static
 432 int _unlink(struct run_as_data *data, struct run_as_ret *ret_value)
 433 {
 434         struct lttng_directory_handle *handle;
 435
 436         handle = lttng_directory_handle_create_from_dirfd(data->u.unlink.dirfd);
 437         if (!handle) {
 438                 ret_value->u.ret = -1;
 439                 ret_value->_errno = errno;
 440                 ret_value->_error = true;
 441                 goto end;
 442         }
 443
 444         /* Ownership of dirfd is transferred to the handle. */
 445         data->u.unlink.dirfd = -1;
 446
 447         ret_value->u.ret = lttng_directory_handle_unlink_file(handle,
 448                         data->u.unlink.path);
 449         ret_value->_errno = errno;
 450         ret_value->_error = (ret_value->u.ret) ? true : false;
 451         lttng_directory_handle_put(handle);
 452 end:
 453         return ret_value->u.ret;
 454 }
 455
 456 static
 457 int _rmdir(struct run_as_data *data, struct run_as_ret *ret_value)
 458 {
 459         struct lttng_directory_handle *handle;
 460
 461         handle = lttng_directory_handle_create_from_dirfd(data->u.rmdir.dirfd);
 462         if (!handle) {
 463                 ret_value->u.ret = -1;
 464                 ret_value->_errno = errno;
 465                 ret_value->_error = true;
 466                 goto end;
 467         }
 468
 469         /* Ownership of dirfd is transferred to the handle. */
 470         data->u.rmdir.dirfd = -1;
 471
 472         ret_value->u.ret = lttng_directory_handle_remove_subdirectory(
 473                         handle, data->u.rmdir.path);
 474         ret_value->_errno = errno;
 475         ret_value->_error = (ret_value->u.ret) ? true : false;
 476         lttng_directory_handle_put(handle);
 477 end:
 478         return ret_value->u.ret;
 479 }
 480
 481 static
 482 int _rmdir_recursive(struct run_as_data *data, struct run_as_ret *ret_value)
 483 {
 484         struct lttng_directory_handle *handle;
 485
 486         handle = lttng_directory_handle_create_from_dirfd(data->u.rmdir.dirfd);
 487         if (!handle) {
 488                 ret_value->u.ret = -1;
 489                 ret_value->_errno = errno;
 490                 ret_value->_error = true;
 491                 goto end;
 492         }
 493
 494         /* Ownership of dirfd is transferred to the handle. */
 495         data->u.rmdir.dirfd = -1;
 496
 497         ret_value->u.ret = lttng_directory_handle_remove_subdirectory_recursive(
 498                         handle, data->u.rmdir.path, data->u.rmdir.flags);
 499         ret_value->_errno = errno;
 500         ret_value->_error = (ret_value->u.ret) ? true : false;
 501         lttng_directory_handle_put(handle);
 502 end:
 503         return ret_value->u.ret;
 504 }
 505
 506 static
 507 int _rename(struct run_as_data *data, struct run_as_ret *ret_value)
 508 {
 509         const char *old_path, *new_path;
 510         struct lttng_directory_handle *old_handle = NULL, *new_handle = NULL;
 511
 512         old_path = data->u.rename.old_path;
 513         new_path = data->u.rename.new_path;
 514
 515         old_handle = lttng_directory_handle_create_from_dirfd(
 516                         data->u.rename.dirfds[0]);
 517         if (!old_handle) {
 518                 ret_value->u.ret = -1;
 519                 goto end;
 520         }
 521         new_handle = lttng_directory_handle_create_from_dirfd(
 522                         data->u.rename.dirfds[1]);
 523         if (!new_handle) {
 524                 ret_value->u.ret = -1;
 525                 goto end;
 526         }
 527
 528         /* Ownership of dirfds are transferred to the handles. */
 529         data->u.rename.dirfds[0] = data->u.rename.dirfds[1] = -1;
 530
 531         /* Safe to call as we have transitioned to the requested uid/gid. */
 532         ret_value->u.ret = lttng_directory_handle_rename(
 533                         old_handle, old_path, new_handle, new_path);
 534 end:
 535         lttng_directory_handle_put(old_handle);
 536         lttng_directory_handle_put(new_handle);
 537         ret_value->_errno = errno;
 538         ret_value->_error = (ret_value->u.ret) ? true : false;
 539         return ret_value->u.ret;
 540 }
 541
 542 #ifdef HAVE_ELF_H
 543 static
 544 int _extract_elf_symbol_offset(struct run_as_data *data,
 545                 struct run_as_ret *ret_value)
 546 {
 547         int ret = 0;
 548         uint64_t offset;
 549
 550         ret_value->_error = false;
 551         ret = lttng_elf_get_symbol_offset(data->u.extract_elf_symbol_offset.fd,
 552                          data->u.extract_elf_symbol_offset.function,
 553                          &offset);
 554         if (ret) {
 555                 DBG("Failed to extract ELF function offset");
 556                 ret_value->_error = true;
 557         }
 558         ret_value->u.extract_elf_symbol_offset.offset = offset;
 559
 560         return ret;
 561 }
 562
 563 static
 564 int _extract_sdt_probe_offsets(struct run_as_data *data,
 565                 struct run_as_ret *ret_value)
 566 {
 567         int ret = 0;
 568         uint64_t *offsets = NULL;
 569         uint32_t num_offset;
 570
 571         ret_value->_error = false;
 572
 573         /* On success, this call allocates the offsets paramater. */
 574         ret = lttng_elf_get_sdt_probe_offsets(
 575                         data->u.extract_sdt_probe_offsets.fd,
 576                         data->u.extract_sdt_probe_offsets.provider_name,
 577                         data->u.extract_sdt_probe_offsets.probe_name,
 578                         &offsets, &num_offset);
 579
 580         if (ret) {
 581                 DBG("Failed to extract SDT probe offsets");
 582                 ret_value->_error = true;
 583                 goto end;
 584         }
 585
 586         if (num_offset <= 0 || num_offset > LTTNG_KERNEL_MAX_UPROBE_NUM) {
 587                 DBG("Wrong number of probes.");
 588                 ret = -1;
 589                 ret_value->_error = true;
 590                 goto free_offset;
 591         }
 592
 593         /* Copy the content of the offsets array to the ret struct. */
 594         memcpy(ret_value->u.extract_sdt_probe_offsets.offsets,
 595                         offsets, num_offset * sizeof(uint64_t));
 596
 597         ret_value->u.extract_sdt_probe_offsets.num_offset = num_offset;
 598
 599 free_offset:
 600         free(offsets);
 601 end:
 602         return ret;
 603 }
 604 #else
 605 static
 606 int _extract_elf_symbol_offset(struct run_as_data *data,
 607                 struct run_as_ret *ret_value)
 608 {
 609         ERR("Unimplemented runas command RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET");
 610         return -1;
 611 }
 612
 613 static
 614 int _extract_sdt_probe_offsets(struct run_as_data *data,
 615                 struct run_as_ret *ret_value)
 616 {
 617         ERR("Unimplemented runas command RUN_AS_EXTRACT_SDT_PROBE_OFFSETS");
 618         return -1;
 619 }
 620 #endif
 621
 622 static
 623 run_as_fct run_as_enum_to_fct(enum run_as_cmd cmd)
 624 {
 625         switch (cmd) {
 626         case RUN_AS_MKDIR:
 627         case RUN_AS_MKDIRAT:
 628                 return _mkdirat;
 629         case RUN_AS_MKDIR_RECURSIVE:
 630         case RUN_AS_MKDIRAT_RECURSIVE:
 631                 return _mkdirat_recursive;
 632         case RUN_AS_OPEN:
 633         case RUN_AS_OPENAT:
 634                 return _open;
 635         case RUN_AS_UNLINK:
 636         case RUN_AS_UNLINKAT:
 637                 return _unlink;
 638         case RUN_AS_RMDIR:
 639         case RUN_AS_RMDIRAT:
 640                 return _rmdir;
 641         case RUN_AS_RMDIR_RECURSIVE:
 642         case RUN_AS_RMDIRAT_RECURSIVE:
 643                 return _rmdir_recursive;
 644         case RUN_AS_RENAME:
 645         case RUN_AS_RENAMEAT:
 646                 return _rename;
 647         case RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET:
 648                 return _extract_elf_symbol_offset;
 649         case RUN_AS_EXTRACT_SDT_PROBE_OFFSETS:
 650                 return _extract_sdt_probe_offsets;
 651         default:
 652                 ERR("Unknown command %d", (int) cmd);
 653                 return NULL;
 654         }
 655 }
 656
 657 static
 658 int do_send_fds(int sock, const int *fds, unsigned int fd_count)
 659 {
 660         ssize_t len;
 661         unsigned int i;
 662
 663         for (i = 0; i < fd_count; i++) {
 664                 if (fds[i] < 0) {
 665                         ERR("Attempt to send invalid file descriptor to master (fd = %i)",
 666                                         fds[i]);
 667                         /* Return 0 as this is not a fatal error. */
 668                         return 0;
 669                 }
 670         }
 671
 672         len = lttcomm_send_fds_unix_sock(sock, fds, fd_count);
 673         return len < 0 ? -1 : 0;
 674 }
 675
 676 static
 677 int do_recv_fds(int sock, int *fds, unsigned int fd_count)
 678 {
 679         int ret = 0;
 680         unsigned int i;
 681         ssize_t len;
 682
 683         len = lttcomm_recv_fds_unix_sock(sock, fds, fd_count);
 684         if (len == 0) {
 685                 ret = -1;
 686                 goto end;
 687         } else if (len < 0) {
 688                 PERROR("Failed to receive file descriptors from socket");
 689                 ret = -1;
 690                 goto end;
 691         }
 692
 693         for (i = 0; i < fd_count; i++) {
 694                 if (fds[i] < 0) {
 695                         ERR("Invalid file descriptor received from worker (fd = %i)", fds[i]);
 696                         /* Return 0 as this is not a fatal error. */
 697                 }
 698         }
 699 end:
 700         return ret;
 701 }
 702
 703 static
 704 int send_fds_to_worker(const struct run_as_worker *worker,
 705                 const struct run_as_data *data)
 706 {
 707         int ret = 0;
 708         unsigned int i;
 709
 710         if (COMMAND_USE_CWD_FD(data) || COMMAND_IN_FD_COUNT(data) == 0) {
 711                 goto end;
 712         }
 713
 714         for (i = 0; i < COMMAND_IN_FD_COUNT(data); i++) {
 715                 if (COMMAND_IN_FDS(data)[i] < 0) {
 716                         ERR("Refusing to send invalid fd to worker (fd = %i)",
 717                                         COMMAND_IN_FDS(data)[i]);
 718                         ret = -1;
 719                         goto end;
 720                 }
 721         }
 722
 723         ret = do_send_fds(worker->sockpair[0], COMMAND_IN_FDS(data),
 724                         COMMAND_IN_FD_COUNT(data));
 725         if (ret < 0) {
 726                 PERROR("Failed to send file descriptor to run-as worker");
 727                 ret = -1;
 728                 goto end;
 729         }
 730 end:
 731         return ret;
 732 }
 733
 734 static
 735 int send_fds_to_master(struct run_as_worker *worker, enum run_as_cmd cmd,
 736                 struct run_as_ret *run_as_ret)
 737 {
 738         int ret = 0;
 739         unsigned int i;
 740
 741         if (COMMAND_OUT_FD_COUNT(cmd) == 0) {
 742                 goto end;
 743         }
 744
 745         ret = do_send_fds(worker->sockpair[1], COMMAND_OUT_FDS(cmd, run_as_ret),
 746                         COMMAND_OUT_FD_COUNT(cmd));
 747         if (ret < 0) {
 748                 PERROR("Failed to send file descriptor to master process");
 749                 goto end;
 750         }
 751
 752         for (i = 0; i < COMMAND_OUT_FD_COUNT(cmd); i++) {
 753                 int ret_close = close(COMMAND_OUT_FDS(cmd, run_as_ret)[i]);
 754
 755                 if (ret_close < 0) {
 756                         PERROR("Failed to close result file descriptor");
 757                 }
 758         }
 759 end:
 760         return ret;
 761 }
 762
 763 static
 764 int recv_fds_from_worker(const struct run_as_worker *worker, enum run_as_cmd cmd,
 765                 struct run_as_ret *run_as_ret)
 766 {
 767         int ret = 0;
 768
 769         if (COMMAND_OUT_FD_COUNT(cmd) == 0) {
 770                 goto end;
 771         }
 772
 773         ret = do_recv_fds(worker->sockpair[0], COMMAND_OUT_FDS(cmd, run_as_ret),
 774                         COMMAND_OUT_FD_COUNT(cmd));
 775         if (ret < 0) {
 776                 PERROR("Failed to receive file descriptor from run-as worker");
 777                 ret = -1;
 778         }
 779 end:
 780         return ret;
 781 }
 782
 783 static
 784 int recv_fds_from_master(struct run_as_worker *worker, struct run_as_data *data)
 785 {
 786         int ret = 0;
 787
 788         if (COMMAND_USE_CWD_FD(data)) {
 789                 unsigned int i;
 790
 791                 for (i = 0; i < COMMAND_IN_FD_COUNT(data); i++) {
 792                         COMMAND_IN_FDS(data)[i] = AT_FDCWD;
 793                 }
 794                 goto end;
 795         }
 796
 797         ret = do_recv_fds(worker->sockpair[1], COMMAND_IN_FDS(data),
 798                         COMMAND_IN_FD_COUNT(data));
 799         if (ret < 0) {
 800                 PERROR("Failed to receive file descriptors from master process");
 801                 ret = -1;
 802         }
 803 end:
 804         return ret;
 805 }
 806
 807 static
 808 int cleanup_received_fds(struct run_as_data *data)
 809 {
 810         int ret = 0, i;
 811
 812         for (i = 0; i < COMMAND_IN_FD_COUNT(data); i++) {
 813                 if (COMMAND_IN_FDS(data)[i] == -1) {
 814                         continue;
 815                 }
 816                 ret = close(COMMAND_IN_FDS(data)[i]);
 817                 if (ret) {
 818                         PERROR("Failed to close file descriptor received fd in run-as worker");
 819                         goto end;
 820                 }
 821         }
 822 end:
 823         return ret;
 824 }
 825
 826 /*
 827  * Return < 0 on error, 0 if OK, 1 on hangup.
 828  */
 829 static
 830 int handle_one_cmd(struct run_as_worker *worker)
 831 {
 832         int ret = 0;
 833         struct run_as_data data = {};
 834         ssize_t readlen, writelen;
 835         struct run_as_ret sendret = {};
 836         run_as_fct cmd;
 837         uid_t prev_euid;
 838
 839         /*
 840          * Stage 1: Receive run_as_data struct from the master.
 841          * The structure contains the command type and all the parameters needed for
 842          * its execution
 843          */
 844         readlen = lttcomm_recv_unix_sock(worker->sockpair[1], &data,
 845                         sizeof(data));
 846         if (readlen == 0) {
 847                 /* hang up */
 848                 ret = 1;
 849                 goto end;
 850         }
 851         if (readlen < sizeof(data)) {
 852                 PERROR("lttcomm_recv_unix_sock error");
 853                 ret = -1;
 854                 goto end;
 855         }
 856
 857         cmd = run_as_enum_to_fct(data.cmd);
 858         if (!cmd) {
 859                 ret = -1;
 860                 goto end;
 861         }
 862
 863         /*
 864          * Stage 2: Receive file descriptor from master.
 865          * Some commands need a file descriptor as input so if it's needed we
 866          * receive the fd using the Unix socket.
 867          */
 868         ret = recv_fds_from_master(worker, &data);
 869         if (ret < 0) {
 870                 PERROR("recv_fd_from_master error");
 871                 ret = -1;
 872                 goto end;
 873         }
 874
 875         prev_euid = getuid();
 876         if (data.gid != getegid()) {
 877                 ret = setegid(data.gid);
 878                 if (ret < 0) {
 879                         sendret._error = true;
 880                         sendret._errno = errno;
 881                         PERROR("setegid");
 882                         goto write_return;
 883                 }
 884         }
 885         if (data.uid != prev_euid) {
 886                 ret = seteuid(data.uid);
 887                 if (ret < 0) {
 888                         sendret._error = true;
 889                         sendret._errno = errno;
 890                         PERROR("seteuid");
 891                         goto write_return;
 892                 }
 893         }
 894
 895         /*
 896          * Also set umask to 0 for mkdir executable bit.
 897          */
 898         umask(0);
 899
 900         /*
 901          * Stage 3: Execute the command
 902          */
 903         ret = (*cmd)(&data, &sendret);
 904         if (ret < 0) {
 905                 DBG("Execution of command returned an error");
 906         }
 907
 908 write_return:
 909         ret = cleanup_received_fds(&data);
 910         if (ret < 0) {
 911                 ERR("Error cleaning up FD");
 912                 goto end;
 913         }
 914
 915         /*
 916          * Stage 4: Send run_as_ret structure to the master.
 917          * This structure contain the return value of the command and the errno.
 918          */
 919         writelen = lttcomm_send_unix_sock(worker->sockpair[1], &sendret,
 920                         sizeof(sendret));
 921         if (writelen < sizeof(sendret)) {
 922                 PERROR("lttcomm_send_unix_sock error");
 923                 ret = -1;
 924                 goto end;
 925         }
 926
 927         /*
 928          * Stage 5: Send resulting file descriptors to the master.
 929          */
 930         ret = send_fds_to_master(worker, data.cmd, &sendret);
 931         if (ret < 0) {
 932                 DBG("Sending FD to master returned an error");
 933                 goto end;
 934         }
 935
 936         if (seteuid(prev_euid) < 0) {
 937                 PERROR("seteuid");
 938                 ret = -1;
 939                 goto end;
 940         }
 941         ret = 0;
 942 end:
 943         return ret;
 944 }
 945
 946 static
 947 int run_as_worker(struct run_as_worker *worker)
 948 {
 949         int ret;
 950         ssize_t writelen;
 951         struct run_as_ret sendret;
 952         size_t proc_orig_len;
 953
 954         /*
 955          * Initialize worker. Set a different process cmdline.
 956          */
 957         proc_orig_len = strlen(worker->procname);
 958         memset(worker->procname, 0, proc_orig_len);
 959         strncpy(worker->procname, DEFAULT_RUN_AS_WORKER_NAME, proc_orig_len);
 960
 961         ret = lttng_thread_setname(DEFAULT_RUN_AS_WORKER_NAME);
 962         if (ret && ret != -ENOSYS) {
 963                 /* Don't fail as this is not essential. */
 964                 DBG("Failed to set pthread name attribute");
 965         }
 966
 967         memset(&sendret, 0, sizeof(sendret));
 968
 969         writelen = lttcomm_send_unix_sock(worker->sockpair[1], &sendret,
 970                         sizeof(sendret));
 971         if (writelen < sizeof(sendret)) {
 972                 PERROR("lttcomm_send_unix_sock error");
 973                 ret = EXIT_FAILURE;
 974                 goto end;
 975         }
 976
 977         for (;;) {
 978                 ret = handle_one_cmd(worker);
 979                 if (ret < 0) {
 980                         ret = EXIT_FAILURE;
 981                         goto end;
 982                 } else if (ret > 0) {
 983                         break;
 984                 } else {
 985                         continue;       /* Next command. */
 986                 }
 987         }
 988         ret = EXIT_SUCCESS;
 989 end:
 990         return ret;
 991 }
 992
 993 static
 994 int run_as_cmd(struct run_as_worker *worker,
 995                 enum run_as_cmd cmd,
 996                 struct run_as_data *data,
 997                 struct run_as_ret *ret_value,
 998                 uid_t uid, gid_t gid)
 999 {
1000         int ret = 0;
1001         ssize_t readlen, writelen;
1002
1003         /*
1004          * If we are non-root, we can only deal with our own uid.
1005          */
1006         if (geteuid() != 0) {
1007                 if (uid != geteuid()) {
1008                         ret = -1;
1009                         ret_value->_errno = EPERM;
1010                         ERR("Client (%d)/Server (%d) UID mismatch (and sessiond is not root)",
1011                                 (int) uid, (int) geteuid());
1012                         goto end;
1013                 }
1014         }
1015
1016         data->cmd = cmd;
1017         data->uid = uid;
1018         data->gid = gid;
1019
1020         /*
1021          * Stage 1: Send the run_as_data struct to the worker process
1022          */
1023         writelen = lttcomm_send_unix_sock(worker->sockpair[0], data,
1024                         sizeof(*data));
1025         if (writelen < sizeof(*data)) {
1026                 PERROR("Error writing message to run_as");
1027                 ret = -1;
1028                 ret_value->_errno = EIO;
1029                 goto end;
1030         }
1031
1032         /*
1033          * Stage 2: Send file descriptor to the worker process if needed
1034          */
1035         ret = send_fds_to_worker(worker, data);
1036         if (ret) {
1037                 PERROR("do_send_fd error");
1038                 ret = -1;
1039                 ret_value->_errno = EIO;
1040                 goto end;
1041         }
1042
1043         /*
1044          * Stage 3: Wait for the execution of the command
1045          */
1046
1047         /*
1048          * Stage 4: Receive the run_as_ret struct containing the return value and
1049          * errno
1050          */
1051         readlen = lttcomm_recv_unix_sock(worker->sockpair[0], ret_value,
1052                         sizeof(*ret_value));
1053         if (!readlen) {
1054                 ERR("Run-as worker has hung-up during run_as_cmd");
1055                 ret = -1;
1056                 ret_value->_errno = EIO;
1057                 goto end;
1058         } else if (readlen < sizeof(*ret_value)) {
1059                 PERROR("Error reading response from run_as");
1060                 ret = -1;
1061                 ret_value->_errno = errno;
1062                 goto end;
1063         }
1064
1065         if (ret_value->_error) {
1066                 /* Skip stage 5 on error as there will be no fd to receive. */
1067                 goto end;
1068         }
1069
1070         /*
1071          * Stage 5: Receive file descriptor if needed
1072          */
1073         ret = recv_fds_from_worker(worker, cmd, ret_value);
1074         if (ret < 0) {
1075                 ERR("Error receiving fd");
1076                 ret = -1;
1077                 ret_value->_errno = EIO;
1078         }
1079
1080 end:
1081         return ret;
1082 }
1083
1084 /*
1085  * This is for debugging ONLY and should not be considered secure.
1086  */
1087 static
1088 int run_as_noworker(enum run_as_cmd cmd,
1089                 struct run_as_data *data, struct run_as_ret *ret_value,
1090                 uid_t uid, gid_t gid)
1091 {
1092         int ret, saved_errno;
1093         mode_t old_mask;
1094         run_as_fct fct;
1095
1096         fct = run_as_enum_to_fct(cmd);
1097         if (!fct) {
1098                 errno = -ENOSYS;
1099                 ret = -1;
1100                 goto end;
1101         }
1102         old_mask = umask(0);
1103         ret = fct(data, ret_value);
1104         saved_errno = ret_value->_errno;
1105         umask(old_mask);
1106         errno = saved_errno;
1107 end:
1108         return ret;
1109 }
1110
1111 static
1112 int reset_sighandler(void)
1113 {
1114         int sig;
1115
1116         DBG("Resetting run_as worker signal handlers to default");
1117         for (sig = 1; sig <= 31; sig++) {
1118                 (void) signal(sig, SIG_DFL);
1119         }
1120         return 0;
1121 }
1122
1123 static
1124 void worker_sighandler(int sig)
1125 {
1126         const char *signame;
1127
1128         /*
1129          * The worker will inherit its parent's signals since they are part of
1130          * the same process group. However, in the case of SIGINT and SIGTERM,
1131          * we want to give the worker a chance to teardown gracefully when its
1132          * parent closes the command socket.
1133          */
1134         switch (sig) {
1135         case SIGINT:
1136                 signame = "SIGINT";
1137                 break;
1138         case SIGTERM:
1139                 signame = "SIGTERM";
1140                 break;
1141         default:
1142                 signame = NULL;
1143         }
1144
1145         if (signame) {
1146                 DBG("run_as worker received signal %s", signame);
1147         } else {
1148                 DBG("run_as_worker received signal %d", sig);
1149         }
1150 }
1151
1152 static
1153 int set_worker_sighandlers(void)
1154 {
1155         int ret = 0;
1156         sigset_t sigset;
1157         struct sigaction sa;
1158
1159         if ((ret = sigemptyset(&sigset)) < 0) {
1160                 PERROR("sigemptyset");
1161                 goto end;
1162         }
1163
1164         sa.sa_handler = worker_sighandler;
1165         sa.sa_mask = sigset;
1166         sa.sa_flags = 0;
1167         if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
1168                 PERROR("sigaction SIGINT");
1169                 goto end;
1170         }
1171
1172         if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
1173                 PERROR("sigaction SIGTERM");
1174                 goto end;
1175         }
1176
1177         DBG("run_as signal handler set for SIGTERM and SIGINT");
1178 end:
1179         return ret;
1180 }
1181
1182 static
1183 int run_as_create_worker_no_lock(const char *procname,
1184                 post_fork_cleanup_cb clean_up_func,
1185                 void *clean_up_user_data)
1186 {
1187         pid_t pid;
1188         int i, ret = 0;
1189         ssize_t readlen;
1190         struct run_as_ret recvret;
1191         struct run_as_worker *worker;
1192
1193         assert(!global_worker);
1194         if (!use_clone()) {
1195                 /*
1196                  * Don't initialize a worker, all run_as tasks will be performed
1197                  * in the current process.
1198                  */
1199                 ret = 0;
1200                 goto end;
1201         }
1202         worker = zmalloc(sizeof(*worker));
1203         if (!worker) {
1204                 ret = -ENOMEM;
1205                 goto end;
1206         }
1207         worker->procname = strdup(procname);
1208         if (!worker->procname) {
1209                 ret = -ENOMEM;
1210                 goto error_procname_alloc;
1211         }
1212         /* Create unix socket. */
1213         if (lttcomm_create_anon_unix_socketpair(worker->sockpair) < 0) {
1214                 ret = -1;
1215                 goto error_sock;
1216         }
1217
1218         /* Fork worker. */
1219         pid = fork();
1220         if (pid < 0) {
1221                 PERROR("fork");
1222                 ret = -1;
1223                 goto error_fork;
1224         } else if (pid == 0) {
1225                 /* Child */
1226
1227                 reset_sighandler();
1228
1229                 set_worker_sighandlers();
1230                 if (clean_up_func) {
1231                         if (clean_up_func(clean_up_user_data) < 0) {
1232                                 ERR("Run-as post-fork clean-up failed, exiting.");
1233                                 exit(EXIT_FAILURE);
1234                         }
1235                 }
1236
1237                 /* Just close, no shutdown. */
1238                 if (close(worker->sockpair[0])) {
1239                         PERROR("close");
1240                         exit(EXIT_FAILURE);
1241                 }
1242
1243                 /*
1244                  * Close all FDs aside from STDIN, STDOUT, STDERR and sockpair[1]
1245                  * Sockpair[1] is used as a control channel with the master
1246                  */
1247                 for (i = 3; i < sysconf(_SC_OPEN_MAX); i++) {
1248                         if (i != worker->sockpair[1]) {
1249                                 (void) close(i);
1250                         }
1251                 }
1252
1253                 worker->sockpair[0] = -1;
1254                 ret = run_as_worker(worker);
1255                 if (lttcomm_close_unix_sock(worker->sockpair[1])) {
1256                         PERROR("close");
1257                         ret = -1;
1258                 }
1259                 worker->sockpair[1] = -1;
1260                 free(worker->procname);
1261                 free(worker);
1262                 LOG(ret ? PRINT_ERR : PRINT_DBG, "run_as worker exiting (ret = %d)", ret);
1263                 exit(ret ? EXIT_FAILURE : EXIT_SUCCESS);
1264         } else {
1265                 /* Parent */
1266
1267                 /* Just close, no shutdown. */
1268                 if (close(worker->sockpair[1])) {
1269                         PERROR("close");
1270                         ret = -1;
1271                         goto error_fork;
1272                 }
1273                 worker->sockpair[1] = -1;
1274                 worker->pid = pid;
1275                 /* Wait for worker to become ready. */
1276                 readlen = lttcomm_recv_unix_sock(worker->sockpair[0],
1277                                 &recvret, sizeof(recvret));
1278                 if (readlen < sizeof(recvret)) {
1279                         ERR("readlen: %zd", readlen);
1280                         PERROR("Error reading response from run_as at creation");
1281                         ret = -1;
1282                         goto error_fork;
1283                 }
1284                 global_worker = worker;
1285         }
1286 end:
1287         return ret;
1288
1289         /* Error handling. */
1290 error_fork:
1291         for (i = 0; i < 2; i++) {
1292                 if (worker->sockpair[i] < 0) {
1293                         continue;
1294                 }
1295                 if (lttcomm_close_unix_sock(worker->sockpair[i])) {
1296                         PERROR("close");
1297                 }
1298                 worker->sockpair[i] = -1;
1299         }
1300 error_sock:
1301         free(worker->procname);
1302 error_procname_alloc:
1303         free(worker);
1304         return ret;
1305 }
1306
1307 static
1308 void run_as_destroy_worker_no_lock(void)
1309 {
1310         struct run_as_worker *worker = global_worker;
1311
1312         DBG("Destroying run_as worker");
1313         if (!worker) {
1314                 return;
1315         }
1316         /* Close unix socket */
1317         DBG("Closing run_as worker socket");
1318         if (lttcomm_close_unix_sock(worker->sockpair[0])) {
1319                 PERROR("close");
1320         }
1321         worker->sockpair[0] = -1;
1322         /* Wait for worker. */
1323         for (;;) {
1324                 int status;
1325                 pid_t wait_ret;
1326
1327                 wait_ret = waitpid(worker->pid, &status, 0);
1328                 if (wait_ret < 0) {
1329                         if (errno == EINTR) {
1330                                 continue;
1331                         }
1332                         PERROR("waitpid");
1333                         break;
1334                 }
1335
1336                 if (WIFEXITED(status)) {
1337                         LOG(WEXITSTATUS(status) == 0 ? PRINT_DBG : PRINT_ERR,
1338                                         DEFAULT_RUN_AS_WORKER_NAME " terminated with status code %d",
1339                                         WEXITSTATUS(status));
1340                         break;
1341                 } else if (WIFSIGNALED(status)) {
1342                         ERR(DEFAULT_RUN_AS_WORKER_NAME " was killed by signal %d",
1343                                         WTERMSIG(status));
1344                         break;
1345                 }
1346         }
1347         free(worker->procname);
1348         free(worker);
1349         global_worker = NULL;
1350 }
1351
1352 static
1353 int run_as_restart_worker(struct run_as_worker *worker)
1354 {
1355         int ret = 0;
1356         char *procname = NULL;
1357
1358         procname = worker->procname;
1359
1360         /* Close socket to run_as worker process and clean up the zombie process */
1361         run_as_destroy_worker_no_lock();
1362
1363         /* Create a new run_as worker process*/
1364         ret = run_as_create_worker_no_lock(procname, NULL, NULL);
1365         if (ret < 0 ) {
1366                 ERR("Restarting the worker process failed");
1367                 ret = -1;
1368                 goto err;
1369         }
1370 err:
1371         return ret;
1372 }
1373
1374 static
1375 int run_as(enum run_as_cmd cmd, struct run_as_data *data,
1376                    struct run_as_ret *ret_value, uid_t uid, gid_t gid)
1377 {
1378         int ret, saved_errno;
1379
1380         pthread_mutex_lock(&worker_lock);
1381         if (use_clone()) {
1382                 DBG("Using run_as worker");
1383
1384                 assert(global_worker);
1385
1386                 ret = run_as_cmd(global_worker, cmd, data, ret_value, uid, gid);
1387                 saved_errno = ret_value->_errno;
1388
1389                 /*
1390                  * If the worker thread crashed the errno is set to EIO. we log
1391                  * the error and  start a new worker process.
1392                  */
1393                 if (ret == -1 && saved_errno == EIO) {
1394                         DBG("Socket closed unexpectedly... "
1395                                         "Restarting the worker process");
1396                         ret = run_as_restart_worker(global_worker);
1397                         if (ret == -1) {
1398                                 ERR("Failed to restart worker process.");
1399                                 goto err;
1400                         }
1401                 }
1402         } else {
1403                 DBG("Using run_as without worker");
1404                 ret = run_as_noworker(cmd, data, ret_value, uid, gid);
1405         }
1406 err:
1407         pthread_mutex_unlock(&worker_lock);
1408         return ret;
1409 }
1410
1411 LTTNG_HIDDEN
1412 int run_as_mkdir_recursive(const char *path, mode_t mode, uid_t uid, gid_t gid)
1413 {
1414         return run_as_mkdirat_recursive(AT_FDCWD, path, mode, uid, gid);
1415 }
1416
1417 LTTNG_HIDDEN
1418 int run_as_mkdirat_recursive(int dirfd, const char *path, mode_t mode,
1419                 uid_t uid, gid_t gid)
1420 {
1421         int ret;
1422         struct run_as_data data = {};
1423         struct run_as_ret run_as_ret = {};
1424
1425         DBG3("mkdirat() recursive fd = %d%s, path = %s, mode = %d, uid = %d, gid = %d",
1426                         dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1427                         path, (int) mode, (int) uid, (int) gid);
1428         ret = lttng_strncpy(data.u.mkdir.path, path,
1429                         sizeof(data.u.mkdir.path));
1430         if (ret) {
1431                 ERR("Failed to copy path argument of mkdirat recursive command");
1432                 goto error;
1433         }
1434         data.u.mkdir.path[sizeof(data.u.mkdir.path) - 1] = '\0';
1435         data.u.mkdir.mode = mode;
1436         data.u.mkdir.dirfd = dirfd;
1437         run_as(dirfd == AT_FDCWD ? RUN_AS_MKDIR_RECURSIVE : RUN_AS_MKDIRAT_RECURSIVE,
1438                         &data, &run_as_ret, uid, gid);
1439         errno = run_as_ret._errno;
1440         ret = run_as_ret.u.ret;
1441 error:
1442         return ret;
1443 }
1444
1445 LTTNG_HIDDEN
1446 int run_as_mkdir(const char *path, mode_t mode, uid_t uid, gid_t gid)
1447 {
1448         return run_as_mkdirat(AT_FDCWD, path, mode, uid, gid);
1449 }
1450
1451 LTTNG_HIDDEN
1452 int run_as_mkdirat(int dirfd, const char *path, mode_t mode,
1453                 uid_t uid, gid_t gid)
1454 {
1455         int ret;
1456         struct run_as_data data = {};
1457         struct run_as_ret run_as_ret = {};
1458
1459         DBG3("mkdirat() recursive fd = %d%s, path = %s, mode = %d, uid = %d, gid = %d",
1460                         dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1461                         path, (int) mode, (int) uid, (int) gid);
1462         ret = lttng_strncpy(data.u.mkdir.path, path,
1463                         sizeof(data.u.mkdir.path));
1464         if (ret) {
1465                 ERR("Failed to copy path argument of mkdirat command");
1466                 goto error;
1467         }
1468         data.u.mkdir.path[sizeof(data.u.mkdir.path) - 1] = '\0';
1469         data.u.mkdir.mode = mode;
1470         data.u.mkdir.dirfd = dirfd;
1471         run_as(dirfd == AT_FDCWD ? RUN_AS_MKDIR : RUN_AS_MKDIRAT,
1472                         &data, &run_as_ret, uid, gid);
1473         errno = run_as_ret._errno;
1474         ret = run_as_ret.u.ret;
1475 error:
1476         return ret;
1477 }
1478
1479 LTTNG_HIDDEN
1480 int run_as_open(const char *path, int flags, mode_t mode, uid_t uid,
1481                 gid_t gid)
1482 {
1483         return run_as_openat(AT_FDCWD, path, flags, mode, uid, gid);
1484 }
1485
1486 LTTNG_HIDDEN
1487 int run_as_openat(int dirfd, const char *path, int flags, mode_t mode,
1488                 uid_t uid, gid_t gid)
1489 {
1490         int ret;
1491         struct run_as_data data = {};
1492         struct run_as_ret run_as_ret = {};
1493
1494         DBG3("openat() fd = %d%s, path = %s, flags = %X, mode = %d, uid %d, gid %d",
1495                         dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1496                         path, flags, (int) mode, (int) uid, (int) gid);
1497         ret = lttng_strncpy(data.u.open.path, path, sizeof(data.u.open.path));
1498         if (ret) {
1499                 ERR("Failed to copy path argument of open command");
1500                 goto error;
1501         }
1502         data.u.open.flags = flags;
1503         data.u.open.mode = mode;
1504         data.u.open.dirfd = dirfd;
1505         run_as(dirfd == AT_FDCWD ? RUN_AS_OPEN : RUN_AS_OPENAT,
1506                         &data, &run_as_ret, uid, gid);
1507         errno = run_as_ret._errno;
1508         ret = run_as_ret.u.ret < 0 ? run_as_ret.u.ret :
1509                         run_as_ret.u.open.fd;
1510 error:
1511         return ret;
1512 }
1513
1514 LTTNG_HIDDEN
1515 int run_as_unlink(const char *path, uid_t uid, gid_t gid)
1516 {
1517         return run_as_unlinkat(AT_FDCWD, path, uid, gid);
1518 }
1519
1520 LTTNG_HIDDEN
1521 int run_as_unlinkat(int dirfd, const char *path, uid_t uid, gid_t gid)
1522 {
1523         int ret;
1524         struct run_as_data data = {};
1525         struct run_as_ret run_as_ret = {};
1526
1527         DBG3("unlinkat() fd = %d%s, path = %s, uid = %d, gid = %d",
1528                         dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1529                         path, (int) uid, (int) gid);
1530         ret = lttng_strncpy(data.u.unlink.path, path,
1531                         sizeof(data.u.unlink.path));
1532         if (ret) {
1533                 goto error;
1534         }
1535         data.u.unlink.dirfd = dirfd;
1536         run_as(dirfd == AT_FDCWD ? RUN_AS_UNLINK : RUN_AS_UNLINKAT, &data,
1537                         &run_as_ret, uid, gid);
1538         errno = run_as_ret._errno;
1539         ret = run_as_ret.u.ret;
1540 error:
1541         return ret;
1542 }
1543
1544 LTTNG_HIDDEN
1545 int run_as_rmdir(const char *path, uid_t uid, gid_t gid)
1546 {
1547         return run_as_rmdirat(AT_FDCWD, path, uid, gid);
1548 }
1549
1550 LTTNG_HIDDEN
1551 int run_as_rmdirat(int dirfd, const char *path, uid_t uid, gid_t gid)
1552 {
1553         int ret;
1554         struct run_as_data data = {};
1555         struct run_as_ret run_as_ret = {};
1556
1557         DBG3("rmdirat() fd = %d%s, path = %s, uid = %d, gid = %d",
1558                         dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1559                         path, (int) uid, (int) gid);
1560         ret = lttng_strncpy(data.u.rmdir.path, path,
1561                         sizeof(data.u.rmdir.path));
1562         if (ret) {
1563                 goto error;
1564         }
1565         data.u.rmdir.dirfd = dirfd;
1566         run_as(dirfd == AT_FDCWD ? RUN_AS_RMDIR : RUN_AS_RMDIRAT, &data,
1567                         &run_as_ret, uid, gid);
1568         errno = run_as_ret._errno;
1569         ret = run_as_ret.u.ret;
1570 error:
1571         return ret;
1572 }
1573
1574 LTTNG_HIDDEN
1575 int run_as_rmdir_recursive(const char *path, uid_t uid, gid_t gid, int flags)
1576 {
1577         return run_as_rmdirat_recursive(AT_FDCWD, path, uid, gid, flags);
1578 }
1579
1580 LTTNG_HIDDEN
1581 int run_as_rmdirat_recursive(int dirfd, const char *path, uid_t uid, gid_t gid, int flags)
1582 {
1583         int ret;
1584         struct run_as_data data = {};
1585         struct run_as_ret run_as_ret = {};
1586
1587         DBG3("rmdirat() recursive fd = %d%s, path = %s, uid = %d, gid = %d",
1588                         dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1589                         path, (int) uid, (int) gid);
1590         ret = lttng_strncpy(data.u.rmdir.path, path,
1591                         sizeof(data.u.rmdir.path));
1592         if (ret) {
1593                 goto error;
1594         }
1595         data.u.rmdir.dirfd = dirfd;
1596         data.u.rmdir.flags = flags;
1597         run_as(dirfd == AT_FDCWD ? RUN_AS_RMDIR_RECURSIVE : RUN_AS_RMDIRAT_RECURSIVE,
1598                         &data, &run_as_ret, uid, gid);
1599         errno = run_as_ret._errno;
1600         ret = run_as_ret.u.ret;
1601 error:
1602         return ret;
1603 }
1604
1605 LTTNG_HIDDEN
1606 int run_as_rename(const char *old, const char *new, uid_t uid, gid_t gid)
1607 {
1608         return run_as_renameat(AT_FDCWD, old, AT_FDCWD, new, uid, gid);
1609 }
1610
1611 LTTNG_HIDDEN
1612 int run_as_renameat(int old_dirfd, const char *old_name,
1613                 int new_dirfd, const char *new_name, uid_t uid, gid_t gid)
1614 {
1615         int ret;
1616         struct run_as_data data = {};
1617         struct run_as_ret run_as_ret = {};
1618
1619         DBG3("renameat() old_dirfd = %d%s, old_name = %s, new_dirfd = %d%s, new_name = %s, uid = %d, gid = %d",
1620                         old_dirfd, old_dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1621                         old_name,
1622                         new_dirfd, new_dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1623                         new_name, (int) uid, (int) gid);
1624         ret = lttng_strncpy(data.u.rename.old_path, old_name,
1625                         sizeof(data.u.rename.old_path));
1626         if (ret) {
1627                 goto error;
1628         }
1629         ret = lttng_strncpy(data.u.rename.new_path, new_name,
1630                         sizeof(data.u.rename.new_path));
1631         if (ret) {
1632                 goto error;
1633         }
1634
1635         data.u.rename.dirfds[0] = old_dirfd;
1636         data.u.rename.dirfds[1] = new_dirfd;
1637         run_as(old_dirfd == AT_FDCWD && new_dirfd == AT_FDCWD ?
1638                         RUN_AS_RENAME : RUN_AS_RENAMEAT,
1639                         &data, &run_as_ret, uid, gid);
1640         errno = run_as_ret._errno;
1641         ret = run_as_ret.u.ret;
1642 error:
1643         return ret;
1644 }
1645
1646 LTTNG_HIDDEN
1647 int run_as_extract_elf_symbol_offset(int fd, const char* function,
1648                 uid_t uid, gid_t gid, uint64_t *offset)
1649 {
1650         int ret;
1651         struct run_as_data data = {};
1652         struct run_as_ret run_as_ret = {};
1653
1654         DBG3("extract_elf_symbol_offset() on fd=%d and function=%s "
1655                         "with for uid %d and gid %d", fd, function,
1656                         (int) uid, (int) gid);
1657
1658         data.u.extract_elf_symbol_offset.fd = fd;
1659
1660         strncpy(data.u.extract_elf_symbol_offset.function, function, LTTNG_SYMBOL_NAME_LEN - 1);
1661         data.u.extract_elf_symbol_offset.function[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
1662         ret = lttng_strncpy(data.u.extract_elf_symbol_offset.function,
1663                         function,
1664                         sizeof(data.u.extract_elf_symbol_offset.function));
1665         if (ret) {
1666                 goto error;
1667         }
1668
1669         run_as(RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET, &data, &run_as_ret, uid, gid);
1670         errno = run_as_ret._errno;
1671         if (run_as_ret._error) {
1672                 ret = -1;
1673                 goto error;
1674         }
1675
1676         *offset = run_as_ret.u.extract_elf_symbol_offset.offset;
1677 error:
1678         return ret;
1679 }
1680
1681 LTTNG_HIDDEN
1682 int run_as_extract_sdt_probe_offsets(int fd, const char* provider_name,
1683                 const char* probe_name, uid_t uid, gid_t gid,
1684                 uint64_t **offsets, uint32_t *num_offset)
1685 {
1686         int ret;
1687         struct run_as_data data = {};
1688         struct run_as_ret run_as_ret = {};
1689
1690         DBG3("extract_sdt_probe_offsets() on fd=%d, probe_name=%s and "
1691                         "provider_name=%s with for uid %d and gid %d", fd,
1692                         probe_name, provider_name, (int) uid, (int) gid);
1693
1694         data.u.extract_sdt_probe_offsets.fd = fd;
1695
1696         ret = lttng_strncpy(data.u.extract_sdt_probe_offsets.probe_name, probe_name,
1697                         sizeof(data.u.extract_sdt_probe_offsets.probe_name));
1698         if (ret) {
1699                 goto error;
1700         }
1701         ret = lttng_strncpy(data.u.extract_sdt_probe_offsets.provider_name,
1702                         provider_name,
1703                         sizeof(data.u.extract_sdt_probe_offsets.provider_name));
1704         if (ret) {
1705                 goto error;
1706         }
1707
1708         run_as(RUN_AS_EXTRACT_SDT_PROBE_OFFSETS, &data, &run_as_ret, uid, gid);
1709         errno = run_as_ret._errno;
1710         if (run_as_ret._error) {
1711                 ret = -1;
1712                 goto error;
1713         }
1714
1715         *num_offset = run_as_ret.u.extract_sdt_probe_offsets.num_offset;
1716         *offsets = zmalloc(*num_offset * sizeof(uint64_t));
1717         if (!*offsets) {
1718                 ret = -ENOMEM;
1719                 goto error;
1720         }
1721
1722         memcpy(*offsets, run_as_ret.u.extract_sdt_probe_offsets.offsets,
1723                         *num_offset * sizeof(uint64_t));
1724 error:
1725         return ret;
1726 }
1727
1728 LTTNG_HIDDEN
1729 int run_as_create_worker(const char *procname,
1730                 post_fork_cleanup_cb clean_up_func,
1731                 void *clean_up_user_data)
1732 {
1733         int ret;
1734
1735         pthread_mutex_lock(&worker_lock);
1736         ret = run_as_create_worker_no_lock(procname, clean_up_func,
1737                         clean_up_user_data);
1738         pthread_mutex_unlock(&worker_lock);
1739         return ret;
1740 }
1741
1742 LTTNG_HIDDEN
1743 void run_as_destroy_worker(void)
1744 {
1745         pthread_mutex_lock(&worker_lock);
1746         run_as_destroy_worker_no_lock();
1747         pthread_mutex_unlock(&worker_lock);
1748 }