src/common/runas.c

   1 /*
   2  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   3  *                      Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  *               2019 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License, version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #define _LGPL_SOURCE
  21 #include <errno.h>
  22 #include <limits.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <sys/wait.h>
  27 #include <sys/types.h>
  28 #include <sys/stat.h>
  29 #include <unistd.h>
  30 #include <fcntl.h>
  31 #include <sched.h>
  32 #include <signal.h>
  33 #include <assert.h>
  34 #include <signal.h>
  35
  36 #include <common/lttng-kernel.h>
  37 #include <common/common.h>
  38 #include <common/utils.h>
  39 #include <common/compat/getenv.h>
  40 #include <common/compat/prctl.h>
  41 #include <common/unix.h>
  42 #include <common/defaults.h>
  43 #include <common/lttng-elf.h>
  44
  45 #include <lttng/constant.h>
  46
  47 #include "runas.h"
  48
  49 struct run_as_data;
  50 struct run_as_ret;
  51 typedef int (*run_as_fct)(struct run_as_data *data, struct run_as_ret *ret_value);
  52
  53 enum run_as_cmd {
  54         RUN_AS_MKDIR,
  55         RUN_AS_MKDIRAT,
  56         RUN_AS_MKDIR_RECURSIVE,
  57         RUN_AS_MKDIRAT_RECURSIVE,
  58         RUN_AS_OPEN,
  59         RUN_AS_OPENAT,
  60         RUN_AS_UNLINK,
  61         RUN_AS_UNLINKAT,
  62         RUN_AS_RMDIR,
  63         RUN_AS_RMDIRAT,
  64         RUN_AS_RMDIR_RECURSIVE,
  65         RUN_AS_RMDIRAT_RECURSIVE,
  66         RUN_AS_RENAME,
  67         RUN_AS_RENAMEAT,
  68         RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET,
  69         RUN_AS_EXTRACT_SDT_PROBE_OFFSETS,
  70 };
  71
  72 struct run_as_mkdir_data {
  73         int dirfd;
  74         char path[LTTNG_PATH_MAX];
  75         mode_t mode;
  76 } LTTNG_PACKED;
  77
  78 struct run_as_open_data {
  79         int dirfd;
  80         char path[LTTNG_PATH_MAX];
  81         int flags;
  82         mode_t mode;
  83 } LTTNG_PACKED;
  84
  85 struct run_as_unlink_data {
  86         int dirfd;
  87         char path[LTTNG_PATH_MAX];
  88 } LTTNG_PACKED;
  89
  90 struct run_as_rmdir_data {
  91         int dirfd;
  92         char path[LTTNG_PATH_MAX];
  93         int flags; /* enum lttng_directory_handle_rmdir_recursive_flags */
  94 } LTTNG_PACKED;
  95
  96 struct run_as_extract_elf_symbol_offset_data {
  97         int fd;
  98         char function[LTTNG_SYMBOL_NAME_LEN];
  99 } LTTNG_PACKED;
 100
 101 struct run_as_extract_sdt_probe_offsets_data {
 102         int fd;
 103         char probe_name[LTTNG_SYMBOL_NAME_LEN];
 104         char provider_name[LTTNG_SYMBOL_NAME_LEN];
 105 } LTTNG_PACKED;
 106
 107 struct run_as_rename_data {
 108         /*
 109          * [0] = old_dirfd
 110          * [1] = new_dirfd
 111          */
 112         int dirfds[2];
 113         char old_path[LTTNG_PATH_MAX];
 114         char new_path[LTTNG_PATH_MAX];
 115 } LTTNG_PACKED;
 116
 117 struct run_as_open_ret {
 118         int fd;
 119 } LTTNG_PACKED;
 120
 121 struct run_as_extract_elf_symbol_offset_ret {
 122         uint64_t offset;
 123 } LTTNG_PACKED;
 124
 125 struct run_as_extract_sdt_probe_offsets_ret {
 126         uint32_t num_offset;
 127         uint64_t offsets[LTTNG_KERNEL_MAX_UPROBE_NUM];
 128 } LTTNG_PACKED;
 129
 130 struct run_as_data {
 131         enum run_as_cmd cmd;
 132         union {
 133                 struct run_as_mkdir_data mkdir;
 134                 struct run_as_open_data open;
 135                 struct run_as_unlink_data unlink;
 136                 struct run_as_rmdir_data rmdir;
 137                 struct run_as_rename_data rename;
 138                 struct run_as_extract_elf_symbol_offset_data extract_elf_symbol_offset;
 139                 struct run_as_extract_sdt_probe_offsets_data extract_sdt_probe_offsets;
 140         } u;
 141         uid_t uid;
 142         gid_t gid;
 143 } LTTNG_PACKED;
 144
 145 /*
 146  * The run_as_ret structure holds the returned value and status of the command.
 147  *
 148  * The `u` union field holds the return value of the command; in most cases it
 149  * represents the success or the failure of the command. In more complex
 150  * commands, it holds a computed value.
 151  *
 152  * The _errno field is the errno recorded after the execution of the command.
 153  *
 154  * The _error fields is used the signify that return status of the command. For
 155  * simple commands returning `int` the _error field will be the same as the
 156  * ret_int field. In complex commands, it signify the success or failure of the
 157  * command.
 158  *
 159  */
 160 struct run_as_ret {
 161         union {
 162                 int ret;
 163                 struct run_as_open_ret open;
 164                 struct run_as_extract_elf_symbol_offset_ret extract_elf_symbol_offset;
 165                 struct run_as_extract_sdt_probe_offsets_ret extract_sdt_probe_offsets;
 166         } u;
 167         int _errno;
 168         bool _error;
 169 } LTTNG_PACKED;
 170
 171 #define COMMAND_IN_FDS(data_ptr) ({                                     \
 172         int *fds = NULL;                                                \
 173         if (command_properties[data_ptr->cmd].in_fds_offset != -1) {    \
 174                 fds = (int *) ((char *) data_ptr + command_properties[data_ptr->cmd].in_fds_offset); \
 175         }                                                               \
 176         fds;                                                            \
 177 })
 178
 179 #define COMMAND_OUT_FDS(cmd, ret_ptr) ({                                \
 180         int *fds = NULL;                                                \
 181         if (command_properties[cmd].out_fds_offset != -1) {             \
 182                 fds = (int *) ((char *) ret_ptr + command_properties[cmd].out_fds_offset); \
 183         }                                                               \
 184         fds;                                                            \
 185 })
 186
 187 #define COMMAND_IN_FD_COUNT(data_ptr) ({                \
 188         command_properties[data_ptr->cmd].in_fd_count;  \
 189 })
 190
 191 #define COMMAND_OUT_FD_COUNT(cmd) ({            \
 192         command_properties[cmd].out_fd_count;   \
 193 })
 194
 195 #define COMMAND_USE_CWD_FD(data_ptr) command_properties[data_ptr->cmd].use_cwd_fd
 196
 197 struct run_as_command_properties {
 198         /* Set to -1 when not applicable. */
 199         ptrdiff_t in_fds_offset, out_fds_offset;
 200         unsigned int in_fd_count, out_fd_count;
 201         bool use_cwd_fd;
 202 };
 203
 204 static const struct run_as_command_properties command_properties[] = {
 205         [RUN_AS_MKDIR] = {
 206                 .in_fds_offset = offsetof(struct run_as_data, u.mkdir.dirfd),
 207                 .in_fd_count = 1,
 208                 .out_fds_offset = -1,
 209                 .out_fd_count = 0,
 210                 .use_cwd_fd = true,
 211         },
 212         [RUN_AS_MKDIRAT] = {
 213                 .in_fds_offset = offsetof(struct run_as_data, u.mkdir.dirfd),
 214                 .in_fd_count = 1,
 215                 .out_fds_offset = -1,
 216                 .out_fd_count = 0,
 217                 .use_cwd_fd = false,
 218         },
 219         [RUN_AS_MKDIR_RECURSIVE] = {
 220                 .in_fds_offset = offsetof(struct run_as_data, u.mkdir.dirfd),
 221                 .in_fd_count = 1,
 222                 .out_fds_offset = -1,
 223                 .out_fd_count = 0,
 224                 .use_cwd_fd = true,
 225         },
 226         [RUN_AS_MKDIRAT_RECURSIVE] = {
 227                 .in_fds_offset = offsetof(struct run_as_data, u.mkdir.dirfd),
 228                 .in_fd_count = 1,
 229                 .out_fds_offset = -1,
 230                 .out_fd_count = 0,
 231                 .use_cwd_fd = false,
 232         },
 233         [RUN_AS_OPEN] = {
 234                 .in_fds_offset = offsetof(struct run_as_data, u.open.dirfd),
 235                 .in_fd_count = 1,
 236                 .out_fds_offset = offsetof(struct run_as_ret, u.open.fd),
 237                 .out_fd_count = 1,
 238                 .use_cwd_fd = true,
 239         },
 240         [RUN_AS_OPENAT] = {
 241                 .in_fds_offset = offsetof(struct run_as_data, u.open.dirfd),
 242                 .in_fd_count = 1,
 243                 .out_fds_offset = offsetof(struct run_as_ret, u.open.fd),
 244                 .out_fd_count = 1,
 245                 .use_cwd_fd = false,
 246         },
 247         [RUN_AS_UNLINK] = {
 248                 .in_fds_offset = offsetof(struct run_as_data, u.unlink.dirfd),
 249                 .in_fd_count = 1,
 250                 .out_fds_offset = -1,
 251                 .out_fd_count = 0,
 252                 .use_cwd_fd = true,
 253         },
 254         [RUN_AS_UNLINKAT] = {
 255                 .in_fds_offset = offsetof(struct run_as_data, u.unlink.dirfd),
 256                 .in_fd_count = 1,
 257                 .out_fds_offset = -1,
 258                 .out_fd_count = 0,
 259                 .use_cwd_fd = false,
 260         },
 261         [RUN_AS_RMDIR_RECURSIVE] = {
 262                 .in_fds_offset = offsetof(struct run_as_data, u.rmdir.dirfd),
 263                 .in_fd_count = 1,
 264                 .out_fds_offset = -1,
 265                 .out_fd_count = 0,
 266                 .use_cwd_fd = true,
 267         },
 268         [RUN_AS_RMDIRAT_RECURSIVE] = {
 269                 .in_fds_offset = offsetof(struct run_as_data, u.rmdir.dirfd),
 270                 .in_fd_count = 1,
 271                 .out_fds_offset = -1,
 272                 .out_fd_count = 0,
 273                 .use_cwd_fd = false,
 274         },
 275         [RUN_AS_RMDIR] = {
 276                 .in_fds_offset = offsetof(struct run_as_data, u.rmdir.dirfd),
 277                 .in_fd_count = 1,
 278                 .out_fds_offset = -1,
 279                 .out_fd_count = 0,
 280                 .use_cwd_fd = true,
 281         },
 282         [RUN_AS_RMDIRAT] = {
 283                 .in_fds_offset = offsetof(struct run_as_data, u.rmdir.dirfd),
 284                 .in_fd_count = 1,
 285                 .out_fds_offset = -1,
 286                 .out_fd_count = 0,
 287                 .use_cwd_fd = false,
 288         },
 289         [RUN_AS_RENAME] = {
 290                 .in_fds_offset = offsetof(struct run_as_data, u.rename.dirfds),
 291                 .in_fd_count = 2,
 292                 .out_fds_offset = -1,
 293                 .out_fd_count = 0,
 294                 .use_cwd_fd = true,
 295         },
 296         [RUN_AS_RENAMEAT] = {
 297                 .in_fds_offset = offsetof(struct run_as_data, u.rename.dirfds),
 298                 .in_fd_count = 2,
 299                 .out_fds_offset = -1,
 300                 .out_fd_count = 0,
 301                 .use_cwd_fd = false,
 302         },
 303         [RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET] = {
 304                 .in_fds_offset = offsetof(struct run_as_data,
 305                                 u.extract_elf_symbol_offset.fd),
 306                 .in_fd_count = 1,
 307                 .out_fds_offset = -1,
 308                 .out_fd_count = 0,
 309                 .use_cwd_fd = false,
 310         },
 311         [RUN_AS_EXTRACT_SDT_PROBE_OFFSETS] = {
 312                 .in_fds_offset = offsetof(struct run_as_data,
 313                                 u.extract_sdt_probe_offsets.fd),
 314                 .in_fd_count = 1,
 315                 .out_fds_offset = -1,
 316                 .out_fd_count = 0,
 317                 .use_cwd_fd = false,
 318         },
 319 };
 320
 321 struct run_as_worker {
 322         pid_t pid;      /* Worker PID. */
 323         int sockpair[2];
 324         char *procname;
 325 };
 326
 327 /* Single global worker per process (for now). */
 328 static struct run_as_worker *global_worker;
 329 /* Lock protecting the worker. */
 330 static pthread_mutex_t worker_lock = PTHREAD_MUTEX_INITIALIZER;
 331
 332 #ifdef VALGRIND
 333 static
 334 int use_clone(void)
 335 {
 336         return 0;
 337 }
 338 #else
 339 static
 340 int use_clone(void)
 341 {
 342         return !lttng_secure_getenv("LTTNG_DEBUG_NOCLONE");
 343 }
 344 #endif
 345
 346 /*
 347  * Create recursively directory using the FULL path.
 348  */
 349 static
 350 int _mkdirat_recursive(struct run_as_data *data, struct run_as_ret *ret_value)
 351 {
 352         const char *path;
 353         mode_t mode;
 354         struct lttng_directory_handle handle;
 355
 356         path = data->u.mkdir.path;
 357         mode = data->u.mkdir.mode;
 358
 359         (void) lttng_directory_handle_init_from_dirfd(&handle,
 360                         data->u.mkdir.dirfd);
 361         /* Ownership of dirfd is transferred to the handle. */
 362         data->u.mkdir.dirfd = -1;
 363         /* Safe to call as we have transitioned to the requested uid/gid. */
 364         ret_value->u.ret =
 365                         lttng_directory_handle_create_subdirectory_recursive(
 366                                         &handle, path, mode);
 367         ret_value->_errno = errno;
 368         ret_value->_error = (ret_value->u.ret) ? true : false;
 369         lttng_directory_handle_fini(&handle);
 370         return ret_value->u.ret;
 371 }
 372
 373 static
 374 int _mkdirat(struct run_as_data *data, struct run_as_ret *ret_value)
 375 {
 376         const char *path;
 377         mode_t mode;
 378         struct lttng_directory_handle handle;
 379
 380         path = data->u.mkdir.path;
 381         mode = data->u.mkdir.mode;
 382
 383         (void) lttng_directory_handle_init_from_dirfd(&handle,
 384                         data->u.mkdir.dirfd);
 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 =
 389                         lttng_directory_handle_create_subdirectory(
 390                                         &handle, path, mode);
 391         ret_value->_errno = errno;
 392         ret_value->_error = (ret_value->u.ret) ? true : false;
 393         lttng_directory_handle_fini(&handle);
 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         (void) lttng_directory_handle_init_from_dirfd(&handle,
 404                         data->u.open.dirfd);
 405         /* Ownership of dirfd is transferred to the handle. */
 406         data->u.open.dirfd = -1;
 407
 408         fd = lttng_directory_handle_open_file(&handle,
 409                         data->u.open.path, data->u.open.flags,
 410                         data->u.open.mode);
 411         if (fd < 0) {
 412                 ret_value->u.ret = -1;
 413                 ret_value->u.open.fd = -1;
 414         } else {
 415                 ret_value->u.ret = 0;
 416                 ret_value->u.open.fd = fd;
 417         }
 418
 419         ret_value->_errno = errno;
 420         ret_value->_error = fd < 0;
 421         lttng_directory_handle_fini(&handle);
 422         return ret_value->u.ret;
 423 }
 424
 425 static
 426 int _unlink(struct run_as_data *data, struct run_as_ret *ret_value)
 427 {
 428         struct lttng_directory_handle handle;
 429
 430         (void) lttng_directory_handle_init_from_dirfd(&handle,
 431                         data->u.unlink.dirfd);
 432
 433         /* Ownership of dirfd is transferred to the handle. */
 434         data->u.unlink.dirfd = -1;
 435
 436         ret_value->u.ret = lttng_directory_handle_unlink_file(&handle,
 437                         data->u.unlink.path);
 438         ret_value->_errno = errno;
 439         ret_value->_error = (ret_value->u.ret) ? true : false;
 440         lttng_directory_handle_fini(&handle);
 441         return ret_value->u.ret;
 442 }
 443
 444 static
 445 int _rmdir(struct run_as_data *data, struct run_as_ret *ret_value)
 446 {
 447         struct lttng_directory_handle handle;
 448
 449         (void) lttng_directory_handle_init_from_dirfd(&handle,
 450                         data->u.rmdir.dirfd);
 451
 452         /* Ownership of dirfd is transferred to the handle. */
 453         data->u.rmdir.dirfd = -1;
 454
 455         ret_value->u.ret = lttng_directory_handle_remove_subdirectory(
 456                         &handle, data->u.rmdir.path);
 457         ret_value->_errno = errno;
 458         ret_value->_error = (ret_value->u.ret) ? true : false;
 459         lttng_directory_handle_fini(&handle);
 460         return ret_value->u.ret;
 461 }
 462
 463 static
 464 int _rmdir_recursive(struct run_as_data *data, struct run_as_ret *ret_value)
 465 {
 466         struct lttng_directory_handle handle;
 467
 468         (void) lttng_directory_handle_init_from_dirfd(&handle,
 469                         data->u.rmdir.dirfd);
 470
 471         /* Ownership of dirfd is transferred to the handle. */
 472         data->u.rmdir.dirfd = -1;
 473
 474         ret_value->u.ret = lttng_directory_handle_remove_subdirectory_recursive(
 475                         &handle, data->u.rmdir.path, data->u.rmdir.flags);
 476         ret_value->_errno = errno;
 477         ret_value->_error = (ret_value->u.ret) ? true : false;
 478         lttng_directory_handle_fini(&handle);
 479         return ret_value->u.ret;
 480 }
 481
 482 static
 483 int _rename(struct run_as_data *data, struct run_as_ret *ret_value)
 484 {
 485         const char *old_path, *new_path;
 486         struct lttng_directory_handle old_handle, new_handle;
 487
 488         old_path = data->u.rename.old_path;
 489         new_path = data->u.rename.new_path;
 490
 491         (void) lttng_directory_handle_init_from_dirfd(&old_handle,
 492                         data->u.rename.dirfds[0]);
 493         (void) lttng_directory_handle_init_from_dirfd(&new_handle,
 494                         data->u.rename.dirfds[1]);
 495
 496         /* Ownership of dirfds are transferred to the handles. */
 497         data->u.rename.dirfds[0] = data->u.rename.dirfds[1] = -1;
 498
 499         /* Safe to call as we have transitioned to the requested uid/gid. */
 500         ret_value->u.ret = lttng_directory_handle_rename(
 501                         &old_handle, old_path, &new_handle, new_path);
 502         ret_value->_errno = errno;
 503         ret_value->_error = (ret_value->u.ret) ? true : false;
 504         lttng_directory_handle_fini(&old_handle);
 505         lttng_directory_handle_fini(&new_handle);
 506         return ret_value->u.ret;
 507 }
 508
 509 #ifdef HAVE_ELF_H
 510 static
 511 int _extract_elf_symbol_offset(struct run_as_data *data,
 512                 struct run_as_ret *ret_value)
 513 {
 514         int ret = 0;
 515
 516         ret_value->_error = false;
 517         ret = lttng_elf_get_symbol_offset(data->u.extract_elf_symbol_offset.fd,
 518                          data->u.extract_elf_symbol_offset.function,
 519                          &ret_value->u.extract_elf_symbol_offset.offset);
 520         if (ret) {
 521                 DBG("Failed to extract ELF function offset");
 522                 ret_value->_error = true;
 523         }
 524
 525         return ret;
 526 }
 527
 528 static
 529 int _extract_sdt_probe_offsets(struct run_as_data *data,
 530                 struct run_as_ret *ret_value)
 531 {
 532         int ret = 0;
 533         uint64_t *offsets = NULL;
 534         uint32_t num_offset;
 535
 536         ret_value->_error = false;
 537
 538         /* On success, this call allocates the offsets paramater. */
 539         ret = lttng_elf_get_sdt_probe_offsets(
 540                         data->u.extract_sdt_probe_offsets.fd,
 541                         data->u.extract_sdt_probe_offsets.provider_name,
 542                         data->u.extract_sdt_probe_offsets.probe_name,
 543                         &offsets, &num_offset);
 544
 545         if (ret) {
 546                 DBG("Failed to extract SDT probe offsets");
 547                 ret_value->_error = true;
 548                 goto end;
 549         }
 550
 551         if (num_offset <= 0 || num_offset > LTTNG_KERNEL_MAX_UPROBE_NUM) {
 552                 DBG("Wrong number of probes.");
 553                 ret = -1;
 554                 ret_value->_error = true;
 555                 goto free_offset;
 556         }
 557
 558         /* Copy the content of the offsets array to the ret struct. */
 559         memcpy(ret_value->u.extract_sdt_probe_offsets.offsets,
 560                         offsets, num_offset * sizeof(uint64_t));
 561
 562         ret_value->u.extract_sdt_probe_offsets.num_offset = num_offset;
 563
 564 free_offset:
 565         free(offsets);
 566 end:
 567         return ret;
 568 }
 569 #else
 570 static
 571 int _extract_elf_symbol_offset(struct run_as_data *data,
 572                 struct run_as_ret *ret_value)
 573 {
 574         ERR("Unimplemented runas command RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET");
 575         return -1;
 576 }
 577
 578 static
 579 int _extract_sdt_probe_offsets(struct run_as_data *data,
 580                 struct run_as_ret *ret_value)
 581 {
 582         ERR("Unimplemented runas command RUN_AS_EXTRACT_SDT_PROBE_OFFSETS");
 583         return -1;
 584 }
 585 #endif
 586
 587 static
 588 run_as_fct run_as_enum_to_fct(enum run_as_cmd cmd)
 589 {
 590         switch (cmd) {
 591         case RUN_AS_MKDIR:
 592         case RUN_AS_MKDIRAT:
 593                 return _mkdirat;
 594         case RUN_AS_MKDIR_RECURSIVE:
 595         case RUN_AS_MKDIRAT_RECURSIVE:
 596                 return _mkdirat_recursive;
 597         case RUN_AS_OPEN:
 598         case RUN_AS_OPENAT:
 599                 return _open;
 600         case RUN_AS_UNLINK:
 601         case RUN_AS_UNLINKAT:
 602                 return _unlink;
 603         case RUN_AS_RMDIR:
 604         case RUN_AS_RMDIRAT:
 605                 return _rmdir;
 606         case RUN_AS_RMDIR_RECURSIVE:
 607         case RUN_AS_RMDIRAT_RECURSIVE:
 608                 return _rmdir_recursive;
 609         case RUN_AS_RENAME:
 610         case RUN_AS_RENAMEAT:
 611                 return _rename;
 612         case RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET:
 613                 return _extract_elf_symbol_offset;
 614         case RUN_AS_EXTRACT_SDT_PROBE_OFFSETS:
 615                 return _extract_sdt_probe_offsets;
 616         default:
 617                 ERR("Unknown command %d", (int) cmd);
 618                 return NULL;
 619         }
 620 }
 621
 622 static
 623 int do_send_fds(int sock, const int *fds, unsigned int fd_count)
 624 {
 625         ssize_t len;
 626         unsigned int i;
 627
 628         for (i = 0; i < fd_count; i++) {
 629                 if (fds[i] < 0) {
 630                         ERR("Attempt to send invalid file descriptor to master (fd = %i)",
 631                                         fds[i]);
 632                         /* Return 0 as this is not a fatal error. */
 633                         return 0;
 634                 }
 635         }
 636
 637         len = lttcomm_send_fds_unix_sock(sock, fds, fd_count);
 638         return len < 0 ? -1 : 0;
 639 }
 640
 641 static
 642 int do_recv_fds(int sock, int *fds, unsigned int fd_count)
 643 {
 644         int ret = 0;
 645         unsigned int i;
 646         ssize_t len;
 647
 648         len = lttcomm_recv_fds_unix_sock(sock, fds, fd_count);
 649         if (len == 0) {
 650                 ret = -1;
 651                 goto end;
 652         } else if (len < 0) {
 653                 PERROR("Failed to receive file descriptors from socket");
 654                 ret = -1;
 655                 goto end;
 656         }
 657
 658         for (i = 0; i < fd_count; i++) {
 659                 if (fds[i] < 0) {
 660                         ERR("Invalid file descriptor received from worker (fd = %i)", fds[i]);
 661                         /* Return 0 as this is not a fatal error. */
 662                 }
 663         }
 664 end:
 665         return ret;
 666 }
 667
 668 static
 669 int send_fds_to_worker(const struct run_as_worker *worker,
 670                 const struct run_as_data *data)
 671 {
 672         int ret = 0;
 673         unsigned int i;
 674
 675         if (COMMAND_USE_CWD_FD(data) || COMMAND_IN_FD_COUNT(data) == 0) {
 676                 goto end;
 677         }
 678
 679         for (i = 0; i < COMMAND_IN_FD_COUNT(data); i++) {
 680                 if (COMMAND_IN_FDS(data)[i] < 0) {
 681                         ERR("Refusing to send invalid fd to worker (fd = %i)",
 682                                         COMMAND_IN_FDS(data)[i]);
 683                         ret = -1;
 684                         goto end;
 685                 }
 686         }
 687
 688         ret = do_send_fds(worker->sockpair[0], COMMAND_IN_FDS(data),
 689                         COMMAND_IN_FD_COUNT(data));
 690         if (ret < 0) {
 691                 PERROR("Failed to send file descriptor to run-as worker");
 692                 ret = -1;
 693                 goto end;
 694         }
 695 end:
 696         return ret;
 697 }
 698
 699 static
 700 int send_fds_to_master(struct run_as_worker *worker, enum run_as_cmd cmd,
 701                 struct run_as_ret *run_as_ret)
 702 {
 703         int ret = 0;
 704         unsigned int i;
 705
 706         if (COMMAND_OUT_FD_COUNT(cmd) == 0) {
 707                 goto end;
 708         }
 709
 710         ret = do_send_fds(worker->sockpair[1], COMMAND_OUT_FDS(cmd, run_as_ret),
 711                         COMMAND_OUT_FD_COUNT(cmd));
 712         if (ret < 0) {
 713                 PERROR("Failed to send file descriptor to master process");
 714                 goto end;
 715         }
 716
 717         for (i = 0; i < COMMAND_OUT_FD_COUNT(cmd); i++) {
 718                 int ret_close = close(COMMAND_OUT_FDS(cmd, run_as_ret)[i]);
 719
 720                 if (ret_close < 0) {
 721                         PERROR("Failed to close result file descriptor");
 722                 }
 723         }
 724 end:
 725         return ret;
 726 }
 727
 728 static
 729 int recv_fds_from_worker(const struct run_as_worker *worker, enum run_as_cmd cmd,
 730                 struct run_as_ret *run_as_ret)
 731 {
 732         int ret = 0;
 733
 734         if (COMMAND_OUT_FD_COUNT(cmd) == 0) {
 735                 goto end;
 736         }
 737
 738         ret = do_recv_fds(worker->sockpair[0], COMMAND_OUT_FDS(cmd, run_as_ret),
 739                         COMMAND_OUT_FD_COUNT(cmd));
 740         if (ret < 0) {
 741                 PERROR("Failed to receive file descriptor from run-as worker");
 742                 ret = -1;
 743         }
 744 end:
 745         return ret;
 746 }
 747
 748 static
 749 int recv_fds_from_master(struct run_as_worker *worker, struct run_as_data *data)
 750 {
 751         int ret = 0;
 752
 753         if (COMMAND_USE_CWD_FD(data)) {
 754                 unsigned int i;
 755
 756                 for (i = 0; i < COMMAND_IN_FD_COUNT(data); i++) {
 757                         COMMAND_IN_FDS(data)[i] = AT_FDCWD;
 758                 }
 759                 goto end;
 760         }
 761
 762         ret = do_recv_fds(worker->sockpair[1], COMMAND_IN_FDS(data),
 763                         COMMAND_IN_FD_COUNT(data));
 764         if (ret < 0) {
 765                 PERROR("Failed to receive file descriptors from master process");
 766                 ret = -1;
 767         }
 768 end:
 769         return ret;
 770 }
 771
 772 static
 773 int cleanup_received_fds(struct run_as_data *data)
 774 {
 775         int ret = 0, i;
 776
 777         for (i = 0; i < COMMAND_IN_FD_COUNT(data); i++) {
 778                 if (COMMAND_IN_FDS(data)[i] == -1) {
 779                         continue;
 780                 }
 781                 ret = close(COMMAND_IN_FDS(data)[i]);
 782                 if (ret) {
 783                         PERROR("Failed to close file descriptor received fd in run-as worker");
 784                         goto end;
 785                 }
 786         }
 787 end:
 788         return ret;
 789 }
 790
 791 /*
 792  * Return < 0 on error, 0 if OK, 1 on hangup.
 793  */
 794 static
 795 int handle_one_cmd(struct run_as_worker *worker)
 796 {
 797         int ret = 0;
 798         struct run_as_data data = {};
 799         ssize_t readlen, writelen;
 800         struct run_as_ret sendret = {};
 801         run_as_fct cmd;
 802         uid_t prev_euid;
 803
 804         /*
 805          * Stage 1: Receive run_as_data struct from the master.
 806          * The structure contains the command type and all the parameters needed for
 807          * its execution
 808          */
 809         readlen = lttcomm_recv_unix_sock(worker->sockpair[1], &data,
 810                         sizeof(data));
 811         if (readlen == 0) {
 812                 /* hang up */
 813                 ret = 1;
 814                 goto end;
 815         }
 816         if (readlen < sizeof(data)) {
 817                 PERROR("lttcomm_recv_unix_sock error");
 818                 ret = -1;
 819                 goto end;
 820         }
 821
 822         cmd = run_as_enum_to_fct(data.cmd);
 823         if (!cmd) {
 824                 ret = -1;
 825                 goto end;
 826         }
 827
 828         /*
 829          * Stage 2: Receive file descriptor from master.
 830          * Some commands need a file descriptor as input so if it's needed we
 831          * receive the fd using the Unix socket.
 832          */
 833         ret = recv_fds_from_master(worker, &data);
 834         if (ret < 0) {
 835                 PERROR("recv_fd_from_master error");
 836                 ret = -1;
 837                 goto end;
 838         }
 839
 840         prev_euid = getuid();
 841         if (data.gid != getegid()) {
 842                 ret = setegid(data.gid);
 843                 if (ret < 0) {
 844                         sendret._error = true;
 845                         sendret._errno = errno;
 846                         PERROR("setegid");
 847                         goto write_return;
 848                 }
 849         }
 850         if (data.uid != prev_euid) {
 851                 ret = seteuid(data.uid);
 852                 if (ret < 0) {
 853                         sendret._error = true;
 854                         sendret._errno = errno;
 855                         PERROR("seteuid");
 856                         goto write_return;
 857                 }
 858         }
 859
 860         /*
 861          * Also set umask to 0 for mkdir executable bit.
 862          */
 863         umask(0);
 864
 865         /*
 866          * Stage 3: Execute the command
 867          */
 868         ret = (*cmd)(&data, &sendret);
 869         if (ret < 0) {
 870                 DBG("Execution of command returned an error");
 871         }
 872
 873 write_return:
 874         ret = cleanup_received_fds(&data);
 875         if (ret < 0) {
 876                 ERR("Error cleaning up FD");
 877                 goto end;
 878         }
 879
 880         /*
 881          * Stage 4: Send run_as_ret structure to the master.
 882          * This structure contain the return value of the command and the errno.
 883          */
 884         writelen = lttcomm_send_unix_sock(worker->sockpair[1], &sendret,
 885                         sizeof(sendret));
 886         if (writelen < sizeof(sendret)) {
 887                 PERROR("lttcomm_send_unix_sock error");
 888                 ret = -1;
 889                 goto end;
 890         }
 891
 892         /*
 893          * Stage 5: Send resulting file descriptors to the master.
 894          */
 895         ret = send_fds_to_master(worker, data.cmd, &sendret);
 896         if (ret < 0) {
 897                 DBG("Sending FD to master returned an error");
 898                 goto end;
 899         }
 900
 901         if (seteuid(prev_euid) < 0) {
 902                 PERROR("seteuid");
 903                 ret = -1;
 904                 goto end;
 905         }
 906         ret = 0;
 907 end:
 908         return ret;
 909 }
 910
 911 static
 912 int run_as_worker(struct run_as_worker *worker)
 913 {
 914         int ret;
 915         ssize_t writelen;
 916         struct run_as_ret sendret;
 917         size_t proc_orig_len;
 918
 919         /*
 920          * Initialize worker. Set a different process cmdline.
 921          */
 922         proc_orig_len = strlen(worker->procname);
 923         memset(worker->procname, 0, proc_orig_len);
 924         strncpy(worker->procname, DEFAULT_RUN_AS_WORKER_NAME, proc_orig_len);
 925
 926         ret = lttng_prctl(PR_SET_NAME,
 927                         (unsigned long) DEFAULT_RUN_AS_WORKER_NAME, 0, 0, 0);
 928         if (ret && ret != -ENOSYS) {
 929                 /* Don't fail as this is not essential. */
 930                 PERROR("prctl PR_SET_NAME");
 931         }
 932
 933         memset(&sendret, 0, sizeof(sendret));
 934
 935         writelen = lttcomm_send_unix_sock(worker->sockpair[1], &sendret,
 936                         sizeof(sendret));
 937         if (writelen < sizeof(sendret)) {
 938                 PERROR("lttcomm_send_unix_sock error");
 939                 ret = EXIT_FAILURE;
 940                 goto end;
 941         }
 942
 943         for (;;) {
 944                 ret = handle_one_cmd(worker);
 945                 if (ret < 0) {
 946                         ret = EXIT_FAILURE;
 947                         goto end;
 948                 } else if (ret > 0) {
 949                         break;
 950                 } else {
 951                         continue;       /* Next command. */
 952                 }
 953         }
 954         ret = EXIT_SUCCESS;
 955 end:
 956         return ret;
 957 }
 958
 959 static
 960 int run_as_cmd(struct run_as_worker *worker,
 961                 enum run_as_cmd cmd,
 962                 struct run_as_data *data,
 963                 struct run_as_ret *ret_value,
 964                 uid_t uid, gid_t gid)
 965 {
 966         int ret = 0;
 967         ssize_t readlen, writelen;
 968
 969         /*
 970          * If we are non-root, we can only deal with our own uid.
 971          */
 972         if (geteuid() != 0) {
 973                 if (uid != geteuid()) {
 974                         ret = -1;
 975                         ret_value->_errno = EPERM;
 976                         ERR("Client (%d)/Server (%d) UID mismatch (and sessiond is not root)",
 977                                 (int) uid, (int) geteuid());
 978                         goto end;
 979                 }
 980         }
 981
 982         data->cmd = cmd;
 983         data->uid = uid;
 984         data->gid = gid;
 985
 986         /*
 987          * Stage 1: Send the run_as_data struct to the worker process
 988          */
 989         writelen = lttcomm_send_unix_sock(worker->sockpair[0], data,
 990                         sizeof(*data));
 991         if (writelen < sizeof(*data)) {
 992                 PERROR("Error writing message to run_as");
 993                 ret = -1;
 994                 ret_value->_errno = EIO;
 995                 goto end;
 996         }
 997
 998         /*
 999          * Stage 2: Send file descriptor to the worker process if needed
1000          */
1001         ret = send_fds_to_worker(worker, data);
1002         if (ret) {
1003                 PERROR("do_send_fd error");
1004                 ret = -1;
1005                 ret_value->_errno = EIO;
1006                 goto end;
1007         }
1008
1009         /*
1010          * Stage 3: Wait for the execution of the command
1011          */
1012
1013         /*
1014          * Stage 4: Receive the run_as_ret struct containing the return value and
1015          * errno
1016          */
1017         readlen = lttcomm_recv_unix_sock(worker->sockpair[0], ret_value,
1018                         sizeof(*ret_value));
1019         if (!readlen) {
1020                 ERR("Run-as worker has hung-up during run_as_cmd");
1021                 ret = -1;
1022                 ret_value->_errno = EIO;
1023                 goto end;
1024         } else if (readlen < sizeof(*ret_value)) {
1025                 PERROR("Error reading response from run_as");
1026                 ret = -1;
1027                 ret_value->_errno = errno;
1028                 goto end;
1029         }
1030
1031         if (ret_value->_error) {
1032                 /* Skip stage 5 on error as there will be no fd to receive. */
1033                 goto end;
1034         }
1035
1036         /*
1037          * Stage 5: Receive file descriptor if needed
1038          */
1039         ret = recv_fds_from_worker(worker, cmd, ret_value);
1040         if (ret < 0) {
1041                 ERR("Error receiving fd");
1042                 ret = -1;
1043                 ret_value->_errno = EIO;
1044         }
1045
1046 end:
1047         return ret;
1048 }
1049
1050 /*
1051  * This is for debugging ONLY and should not be considered secure.
1052  */
1053 static
1054 int run_as_noworker(enum run_as_cmd cmd,
1055                 struct run_as_data *data, struct run_as_ret *ret_value,
1056                 uid_t uid, gid_t gid)
1057 {
1058         int ret, saved_errno;
1059         mode_t old_mask;
1060         run_as_fct fct;
1061
1062         fct = run_as_enum_to_fct(cmd);
1063         if (!fct) {
1064                 errno = -ENOSYS;
1065                 ret = -1;
1066                 goto end;
1067         }
1068         old_mask = umask(0);
1069         ret = fct(data, ret_value);
1070         saved_errno = ret_value->_errno;
1071         umask(old_mask);
1072         errno = saved_errno;
1073 end:
1074         return ret;
1075 }
1076
1077 static
1078 int reset_sighandler(void)
1079 {
1080         int sig;
1081
1082         DBG("Resetting run_as worker signal handlers to default");
1083         for (sig = 1; sig <= 31; sig++) {
1084                 (void) signal(sig, SIG_DFL);
1085         }
1086         return 0;
1087 }
1088
1089 static
1090 void worker_sighandler(int sig)
1091 {
1092         const char *signame;
1093
1094         /*
1095          * The worker will inherit its parent's signals since they are part of
1096          * the same process group. However, in the case of SIGINT and SIGTERM,
1097          * we want to give the worker a chance to teardown gracefully when its
1098          * parent closes the command socket.
1099          */
1100         switch (sig) {
1101         case SIGINT:
1102                 signame = "SIGINT";
1103                 break;
1104         case SIGTERM:
1105                 signame = "SIGTERM";
1106                 break;
1107         default:
1108                 signame = NULL;
1109         }
1110
1111         if (signame) {
1112                 DBG("run_as worker received signal %s", signame);
1113         } else {
1114                 DBG("run_as_worker received signal %d", sig);
1115         }
1116 }
1117
1118 static
1119 int set_worker_sighandlers(void)
1120 {
1121         int ret = 0;
1122         sigset_t sigset;
1123         struct sigaction sa;
1124
1125         if ((ret = sigemptyset(&sigset)) < 0) {
1126                 PERROR("sigemptyset");
1127                 goto end;
1128         }
1129
1130         sa.sa_handler = worker_sighandler;
1131         sa.sa_mask = sigset;
1132         sa.sa_flags = 0;
1133         if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
1134                 PERROR("sigaction SIGINT");
1135                 goto end;
1136         }
1137
1138         if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
1139                 PERROR("sigaction SIGTERM");
1140                 goto end;
1141         }
1142
1143         DBG("run_as signal handler set for SIGTERM and SIGINT");
1144 end:
1145         return ret;
1146 }
1147
1148 static
1149 int run_as_create_worker_no_lock(const char *procname,
1150                 post_fork_cleanup_cb clean_up_func,
1151                 void *clean_up_user_data)
1152 {
1153         pid_t pid;
1154         int i, ret = 0;
1155         ssize_t readlen;
1156         struct run_as_ret recvret;
1157         struct run_as_worker *worker;
1158
1159         assert(!global_worker);
1160         if (!use_clone()) {
1161                 /*
1162                  * Don't initialize a worker, all run_as tasks will be performed
1163                  * in the current process.
1164                  */
1165                 ret = 0;
1166                 goto end;
1167         }
1168         worker = zmalloc(sizeof(*worker));
1169         if (!worker) {
1170                 ret = -ENOMEM;
1171                 goto end;
1172         }
1173         worker->procname = strdup(procname);
1174         if (!worker->procname) {
1175                 ret = -ENOMEM;
1176                 goto error_procname_alloc;
1177         }
1178         /* Create unix socket. */
1179         if (lttcomm_create_anon_unix_socketpair(worker->sockpair) < 0) {
1180                 ret = -1;
1181                 goto error_sock;
1182         }
1183
1184         /* Fork worker. */
1185         pid = fork();
1186         if (pid < 0) {
1187                 PERROR("fork");
1188                 ret = -1;
1189                 goto error_fork;
1190         } else if (pid == 0) {
1191                 /* Child */
1192
1193                 reset_sighandler();
1194
1195                 set_worker_sighandlers();
1196                 if (clean_up_func) {
1197                         if (clean_up_func(clean_up_user_data) < 0) {
1198                                 ERR("Run-as post-fork clean-up failed, exiting.");
1199                                 exit(EXIT_FAILURE);
1200                         }
1201                 }
1202
1203                 /* Just close, no shutdown. */
1204                 if (close(worker->sockpair[0])) {
1205                         PERROR("close");
1206                         exit(EXIT_FAILURE);
1207                 }
1208
1209                 /*
1210                  * Close all FDs aside from STDIN, STDOUT, STDERR and sockpair[1]
1211                  * Sockpair[1] is used as a control channel with the master
1212                  */
1213                 for (i = 3; i < sysconf(_SC_OPEN_MAX); i++) {
1214                         if (i != worker->sockpair[1]) {
1215                                 (void) close(i);
1216                         }
1217                 }
1218
1219                 worker->sockpair[0] = -1;
1220                 ret = run_as_worker(worker);
1221                 if (lttcomm_close_unix_sock(worker->sockpair[1])) {
1222                         PERROR("close");
1223                         ret = -1;
1224                 }
1225                 worker->sockpair[1] = -1;
1226                 free(worker->procname);
1227                 free(worker);
1228                 LOG(ret ? PRINT_ERR : PRINT_DBG, "run_as worker exiting (ret = %d)", ret);
1229                 exit(ret ? EXIT_FAILURE : EXIT_SUCCESS);
1230         } else {
1231                 /* Parent */
1232
1233                 /* Just close, no shutdown. */
1234                 if (close(worker->sockpair[1])) {
1235                         PERROR("close");
1236                         ret = -1;
1237                         goto error_fork;
1238                 }
1239                 worker->sockpair[1] = -1;
1240                 worker->pid = pid;
1241                 /* Wait for worker to become ready. */
1242                 readlen = lttcomm_recv_unix_sock(worker->sockpair[0],
1243                                 &recvret, sizeof(recvret));
1244                 if (readlen < sizeof(recvret)) {
1245                         ERR("readlen: %zd", readlen);
1246                         PERROR("Error reading response from run_as at creation");
1247                         ret = -1;
1248                         goto error_fork;
1249                 }
1250                 global_worker = worker;
1251         }
1252 end:
1253         return ret;
1254
1255         /* Error handling. */
1256 error_fork:
1257         for (i = 0; i < 2; i++) {
1258                 if (worker->sockpair[i] < 0) {
1259                         continue;
1260                 }
1261                 if (lttcomm_close_unix_sock(worker->sockpair[i])) {
1262                         PERROR("close");
1263                 }
1264                 worker->sockpair[i] = -1;
1265         }
1266 error_sock:
1267         free(worker->procname);
1268 error_procname_alloc:
1269         free(worker);
1270         return ret;
1271 }
1272
1273 static
1274 void run_as_destroy_worker_no_lock(void)
1275 {
1276         struct run_as_worker *worker = global_worker;
1277
1278         DBG("Destroying run_as worker");
1279         if (!worker) {
1280                 return;
1281         }
1282         /* Close unix socket */
1283         DBG("Closing run_as worker socket");
1284         if (lttcomm_close_unix_sock(worker->sockpair[0])) {
1285                 PERROR("close");
1286         }
1287         worker->sockpair[0] = -1;
1288         /* Wait for worker. */
1289         for (;;) {
1290                 int status;
1291                 pid_t wait_ret;
1292
1293                 wait_ret = waitpid(worker->pid, &status, 0);
1294                 if (wait_ret < 0) {
1295                         if (errno == EINTR) {
1296                                 continue;
1297                         }
1298                         PERROR("waitpid");
1299                         break;
1300                 }
1301
1302                 if (WIFEXITED(status)) {
1303                         LOG(WEXITSTATUS(status) == 0 ? PRINT_DBG : PRINT_ERR,
1304                                         DEFAULT_RUN_AS_WORKER_NAME " terminated with status code %d",
1305                                         WEXITSTATUS(status));
1306                         break;
1307                 } else if (WIFSIGNALED(status)) {
1308                         ERR(DEFAULT_RUN_AS_WORKER_NAME " was killed by signal %d",
1309                                         WTERMSIG(status));
1310                         break;
1311                 }
1312         }
1313         free(worker->procname);
1314         free(worker);
1315         global_worker = NULL;
1316 }
1317
1318 static
1319 int run_as_restart_worker(struct run_as_worker *worker)
1320 {
1321         int ret = 0;
1322         char *procname = NULL;
1323
1324         procname = worker->procname;
1325
1326         /* Close socket to run_as worker process and clean up the zombie process */
1327         run_as_destroy_worker_no_lock();
1328
1329         /* Create a new run_as worker process*/
1330         ret = run_as_create_worker_no_lock(procname, NULL, NULL);
1331         if (ret < 0 ) {
1332                 ERR("Restarting the worker process failed");
1333                 ret = -1;
1334                 goto err;
1335         }
1336 err:
1337         return ret;
1338 }
1339
1340 static
1341 int run_as(enum run_as_cmd cmd, struct run_as_data *data,
1342                    struct run_as_ret *ret_value, uid_t uid, gid_t gid)
1343 {
1344         int ret, saved_errno;
1345
1346         pthread_mutex_lock(&worker_lock);
1347         if (use_clone()) {
1348                 DBG("Using run_as worker");
1349
1350                 assert(global_worker);
1351
1352                 ret = run_as_cmd(global_worker, cmd, data, ret_value, uid, gid);
1353                 saved_errno = ret_value->_errno;
1354
1355                 /*
1356                  * If the worker thread crashed the errno is set to EIO. we log
1357                  * the error and  start a new worker process.
1358                  */
1359                 if (ret == -1 && saved_errno == EIO) {
1360                         DBG("Socket closed unexpectedly... "
1361                                         "Restarting the worker process");
1362                         ret = run_as_restart_worker(global_worker);
1363
1364                         if (ret == -1) {
1365                                 ERR("Failed to restart worker process.");
1366                                 goto err;
1367                         }
1368                 }
1369         } else {
1370                 DBG("Using run_as without worker");
1371                 ret = run_as_noworker(cmd, data, ret_value, uid, gid);
1372         }
1373 err:
1374         pthread_mutex_unlock(&worker_lock);
1375         return ret;
1376 }
1377
1378 LTTNG_HIDDEN
1379 int run_as_mkdir_recursive(const char *path, mode_t mode, uid_t uid, gid_t gid)
1380 {
1381         return run_as_mkdirat_recursive(AT_FDCWD, path, mode, uid, gid);
1382 }
1383
1384 LTTNG_HIDDEN
1385 int run_as_mkdirat_recursive(int dirfd, const char *path, mode_t mode,
1386                 uid_t uid, gid_t gid)
1387 {
1388         int ret;
1389         struct run_as_data data = {};
1390         struct run_as_ret run_as_ret = {};
1391
1392         DBG3("mkdirat() recursive fd = %d%s, path = %s, mode = %d, uid = %d, gid = %d",
1393                         dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1394                         path, (int) mode, (int) uid, (int) gid);
1395         ret = lttng_strncpy(data.u.mkdir.path, path,
1396                         sizeof(data.u.mkdir.path));
1397         if (ret) {
1398                 ERR("Failed to copy path argument of mkdirat recursive command");
1399                 goto error;
1400         }
1401         data.u.mkdir.path[sizeof(data.u.mkdir.path) - 1] = '\0';
1402         data.u.mkdir.mode = mode;
1403         data.u.mkdir.dirfd = dirfd;
1404         run_as(dirfd == AT_FDCWD ? RUN_AS_MKDIR_RECURSIVE : RUN_AS_MKDIRAT_RECURSIVE,
1405                         &data, &run_as_ret, uid, gid);
1406         errno = run_as_ret._errno;
1407         ret = run_as_ret.u.ret;
1408 error:
1409         return ret;
1410 }
1411
1412 LTTNG_HIDDEN
1413 int run_as_mkdir(const char *path, mode_t mode, uid_t uid, gid_t gid)
1414 {
1415         return run_as_mkdirat(AT_FDCWD, path, mode, uid, gid);
1416 }
1417
1418 LTTNG_HIDDEN
1419 int run_as_mkdirat(int dirfd, const char *path, mode_t mode,
1420                 uid_t uid, gid_t gid)
1421 {
1422         int ret;
1423         struct run_as_data data = {};
1424         struct run_as_ret run_as_ret = {};
1425
1426         DBG3("mkdirat() recursive fd = %d%s, path = %s, mode = %d, uid = %d, gid = %d",
1427                         dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1428                         path, (int) mode, (int) uid, (int) gid);
1429         ret = lttng_strncpy(data.u.mkdir.path, path,
1430                         sizeof(data.u.mkdir.path));
1431         if (ret) {
1432                 ERR("Failed to copy path argument of mkdirat command");
1433                 goto error;
1434         }
1435         data.u.mkdir.path[sizeof(data.u.mkdir.path) - 1] = '\0';
1436         data.u.mkdir.mode = mode;
1437         data.u.mkdir.dirfd = dirfd;
1438         run_as(dirfd == AT_FDCWD ? RUN_AS_MKDIR : RUN_AS_MKDIRAT,
1439                         &data, &run_as_ret, uid, gid);
1440         errno = run_as_ret._errno;
1441         ret = run_as_ret.u.ret;
1442 error:
1443         return ret;
1444 }
1445
1446 LTTNG_HIDDEN
1447 int run_as_open(const char *path, int flags, mode_t mode, uid_t uid,
1448                 gid_t gid)
1449 {
1450         return run_as_openat(AT_FDCWD, path, flags, mode, uid, gid);
1451 }
1452
1453 LTTNG_HIDDEN
1454 int run_as_openat(int dirfd, const char *path, int flags, mode_t mode,
1455                 uid_t uid, gid_t gid)
1456 {
1457         int ret;
1458         struct run_as_data data = {};
1459         struct run_as_ret run_as_ret = {};
1460
1461         DBG3("openat() fd = %d%s, path = %s, flags = %X, mode = %d, uid %d, gid %d",
1462                         dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1463                         path, flags, (int) mode, (int) uid, (int) gid);
1464         ret = lttng_strncpy(data.u.open.path, path, sizeof(data.u.open.path));
1465         if (ret) {
1466                 ERR("Failed to copy path argument of open command");
1467                 goto error;
1468         }
1469         data.u.open.flags = flags;
1470         data.u.open.mode = mode;
1471         data.u.open.dirfd = dirfd;
1472         run_as(dirfd == AT_FDCWD ? RUN_AS_OPEN : RUN_AS_OPENAT,
1473                         &data, &run_as_ret, uid, gid);
1474         errno = run_as_ret._errno;
1475         ret = run_as_ret.u.ret < 0 ? run_as_ret.u.ret :
1476                         run_as_ret.u.open.fd;
1477 error:
1478         return ret;
1479 }
1480
1481 LTTNG_HIDDEN
1482 int run_as_unlink(const char *path, uid_t uid, gid_t gid)
1483 {
1484         return run_as_unlinkat(AT_FDCWD, path, uid, gid);
1485 }
1486
1487 LTTNG_HIDDEN
1488 int run_as_unlinkat(int dirfd, const char *path, 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("unlinkat() fd = %d%s, path = %s, uid = %d, gid = %d",
1495                         dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1496                         path, (int) uid, (int) gid);
1497         ret = lttng_strncpy(data.u.unlink.path, path,
1498                         sizeof(data.u.unlink.path));
1499         if (ret) {
1500                 goto error;
1501         }
1502         data.u.unlink.dirfd = dirfd;
1503         run_as(dirfd == AT_FDCWD ? RUN_AS_UNLINK : RUN_AS_UNLINKAT, &data,
1504                         &run_as_ret, uid, gid);
1505         errno = run_as_ret._errno;
1506         ret = run_as_ret.u.ret;
1507 error:
1508         return ret;
1509 }
1510
1511 LTTNG_HIDDEN
1512 int run_as_rmdir(const char *path, uid_t uid, gid_t gid)
1513 {
1514         return run_as_rmdirat(AT_FDCWD, path, uid, gid);
1515 }
1516
1517 LTTNG_HIDDEN
1518 int run_as_rmdirat(int dirfd, const char *path, uid_t uid, gid_t gid)
1519 {
1520         int ret;
1521         struct run_as_data data = {};
1522         struct run_as_ret run_as_ret = {};
1523
1524         DBG3("rmdirat() fd = %d%s, path = %s, uid = %d, gid = %d",
1525                         dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1526                         path, (int) uid, (int) gid);
1527         ret = lttng_strncpy(data.u.rmdir.path, path,
1528                         sizeof(data.u.rmdir.path));
1529         if (ret) {
1530                 goto error;
1531         }
1532         data.u.rmdir.dirfd = dirfd;
1533         run_as(dirfd == AT_FDCWD ? RUN_AS_RMDIR : RUN_AS_RMDIRAT, &data,
1534                         &run_as_ret, uid, gid);
1535         errno = run_as_ret._errno;
1536         ret = run_as_ret.u.ret;
1537 error:
1538         return ret;
1539 }
1540
1541 LTTNG_HIDDEN
1542 int run_as_rmdir_recursive(const char *path, uid_t uid, gid_t gid, int flags)
1543 {
1544         return run_as_rmdirat_recursive(AT_FDCWD, path, uid, gid, flags);
1545 }
1546
1547 LTTNG_HIDDEN
1548 int run_as_rmdirat_recursive(int dirfd, const char *path, uid_t uid, gid_t gid, int flags)
1549 {
1550         int ret;
1551         struct run_as_data data = {};
1552         struct run_as_ret run_as_ret = {};
1553
1554         DBG3("rmdirat() recursive fd = %d%s, path = %s, uid = %d, gid = %d",
1555                         dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1556                         path, (int) uid, (int) gid);
1557         ret = lttng_strncpy(data.u.rmdir.path, path,
1558                         sizeof(data.u.rmdir.path));
1559         if (ret) {
1560                 goto error;
1561         }
1562         data.u.rmdir.dirfd = dirfd;
1563         data.u.rmdir.flags = flags;
1564         run_as(dirfd == AT_FDCWD ? RUN_AS_RMDIR_RECURSIVE : RUN_AS_RMDIRAT_RECURSIVE,
1565                         &data, &run_as_ret, uid, gid);
1566         errno = run_as_ret._errno;
1567         ret = run_as_ret.u.ret;
1568 error:
1569         return ret;
1570 }
1571
1572 LTTNG_HIDDEN
1573 int run_as_rename(const char *old, const char *new, uid_t uid, gid_t gid)
1574 {
1575         return run_as_renameat(AT_FDCWD, old, AT_FDCWD, new, uid, gid);
1576 }
1577
1578 LTTNG_HIDDEN
1579 int run_as_renameat(int old_dirfd, const char *old_name,
1580                 int new_dirfd, const char *new_name, uid_t uid, gid_t gid)
1581 {
1582         int ret;
1583         struct run_as_data data = {};
1584         struct run_as_ret run_as_ret = {};
1585
1586         DBG3("renameat() old_dirfd = %d%s, old_name = %s, new_dirfd = %d%s, new_name = %s, uid = %d, gid = %d",
1587                         old_dirfd, old_dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1588                         old_name,
1589                         new_dirfd, new_dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
1590                         new_name, (int) uid, (int) gid);
1591         ret = lttng_strncpy(data.u.rename.old_path, old_name,
1592                         sizeof(data.u.rename.old_path));
1593         if (ret) {
1594                 goto error;
1595         }
1596         ret = lttng_strncpy(data.u.rename.new_path, new_name,
1597                         sizeof(data.u.rename.new_path));
1598         if (ret) {
1599                 goto error;
1600         }
1601
1602         data.u.rename.dirfds[0] = old_dirfd;
1603         data.u.rename.dirfds[1] = new_dirfd;
1604         run_as(old_dirfd == AT_FDCWD && new_dirfd == AT_FDCWD ?
1605                         RUN_AS_RENAME : RUN_AS_RENAMEAT,
1606                         &data, &run_as_ret, uid, gid);
1607         errno = run_as_ret._errno;
1608         ret = run_as_ret.u.ret;
1609 error:
1610         return ret;
1611 }
1612
1613 LTTNG_HIDDEN
1614 int run_as_extract_elf_symbol_offset(int fd, const char* function,
1615                 uid_t uid, gid_t gid, uint64_t *offset)
1616 {
1617         int ret;
1618         struct run_as_data data = {};
1619         struct run_as_ret run_as_ret = {};
1620
1621         DBG3("extract_elf_symbol_offset() on fd=%d and function=%s "
1622                         "with for uid %d and gid %d", fd, function,
1623                         (int) uid, (int) gid);
1624
1625         data.u.extract_elf_symbol_offset.fd = fd;
1626
1627         strncpy(data.u.extract_elf_symbol_offset.function, function, LTTNG_SYMBOL_NAME_LEN - 1);
1628         data.u.extract_elf_symbol_offset.function[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
1629         ret = lttng_strncpy(data.u.extract_elf_symbol_offset.function,
1630                         function,
1631                         sizeof(data.u.extract_elf_symbol_offset.function));
1632         if (ret) {
1633                 goto error;
1634         }
1635
1636         run_as(RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET, &data, &run_as_ret, uid, gid);
1637         errno = run_as_ret._errno;
1638         if (run_as_ret._error) {
1639                 ret = -1;
1640                 goto error;
1641         }
1642
1643         *offset = run_as_ret.u.extract_elf_symbol_offset.offset;
1644 error:
1645         return ret;
1646 }
1647
1648 LTTNG_HIDDEN
1649 int run_as_extract_sdt_probe_offsets(int fd, const char* provider_name,
1650                 const char* probe_name, uid_t uid, gid_t gid,
1651                 uint64_t **offsets, uint32_t *num_offset)
1652 {
1653         int ret;
1654         struct run_as_data data = {};
1655         struct run_as_ret run_as_ret = {};
1656
1657         DBG3("extract_sdt_probe_offsets() on fd=%d, probe_name=%s and "
1658                         "provider_name=%s with for uid %d and gid %d", fd,
1659                         probe_name, provider_name, (int) uid, (int) gid);
1660
1661         data.u.extract_sdt_probe_offsets.fd = fd;
1662
1663         ret = lttng_strncpy(data.u.extract_sdt_probe_offsets.probe_name, probe_name,
1664                         sizeof(data.u.extract_sdt_probe_offsets.probe_name));
1665         if (ret) {
1666                 goto error;
1667         }
1668         ret = lttng_strncpy(data.u.extract_sdt_probe_offsets.provider_name,
1669                         provider_name,
1670                         sizeof(data.u.extract_sdt_probe_offsets.provider_name));
1671         if (ret) {
1672                 goto error;
1673         }
1674
1675         run_as(RUN_AS_EXTRACT_SDT_PROBE_OFFSETS, &data, &run_as_ret, uid, gid);
1676         errno = run_as_ret._errno;
1677         if (run_as_ret._error) {
1678                 ret = -1;
1679                 goto error;
1680         }
1681
1682         *num_offset = run_as_ret.u.extract_sdt_probe_offsets.num_offset;
1683         *offsets = zmalloc(*num_offset * sizeof(uint64_t));
1684         if (!*offsets) {
1685                 ret = -ENOMEM;
1686                 goto error;
1687         }
1688
1689         memcpy(*offsets, run_as_ret.u.extract_sdt_probe_offsets.offsets,
1690                         *num_offset * sizeof(uint64_t));
1691 error:
1692         return ret;
1693 }
1694
1695 LTTNG_HIDDEN
1696 int run_as_create_worker(const char *procname,
1697                 post_fork_cleanup_cb clean_up_func,
1698                 void *clean_up_user_data)
1699 {
1700         int ret;
1701
1702         pthread_mutex_lock(&worker_lock);
1703         ret = run_as_create_worker_no_lock(procname, clean_up_func,
1704                         clean_up_user_data);
1705         pthread_mutex_unlock(&worker_lock);
1706         return ret;
1707 }
1708
1709 LTTNG_HIDDEN
1710 void run_as_destroy_worker(void)
1711 {
1712         pthread_mutex_lock(&worker_lock);
1713         run_as_destroy_worker_no_lock();
1714         pthread_mutex_unlock(&worker_lock);
1715 }