source3/lib/system.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Samba system utilities
   4    Copyright (C) Andrew Tridgell 1992-1998
   5    Copyright (C) Jeremy Allison  1998-2005
   6    Copyright (C) Timur Bakeyev        2005
   7    Copyright (C) Bjoern Jacke    2006-2007
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include "includes.h"
  24 #include "system/syslog.h"
  25 #include "system/capability.h"
  26 #include "system/passwd.h"
  27 #include "system/filesys.h"
  28 #include "lib/util/setid.h"
  29 #include "lib/util/time.h"
  30
  31 #ifdef HAVE_SYS_SYSCTL_H
  32 #include <sys/sysctl.h>
  33 #endif
  34
  35 #ifdef HAVE_SYS_PRCTL_H
  36 #include <sys/prctl.h>
  37 #endif
  38
  39 /*
  40    The idea is that this file will eventually have wrappers around all
  41    important system calls in samba. The aims are:
  42
  43    - to enable easier porting by putting OS dependent stuff in here
  44
  45    - to allow for hooks into other "pseudo-filesystems"
  46
  47    - to allow easier integration of things like the japanese extensions
  48
  49    - to support the philosophy of Samba to expose the features of
  50      the OS within the SMB model. In general whatever file/printer/variable
  51      expansions/etc make sense to the OS should be acceptable to Samba.
  52 */
  53
  54 /*******************************************************************
  55 A send wrapper that will deal with EINTR or EAGAIN or EWOULDBLOCK.
  56 ********************************************************************/
  57
  58 ssize_t sys_send(int s, const void *msg, size_t len, int flags)
  59 {
  60         ssize_t ret;
  61
  62         do {
  63                 ret = send(s, msg, len, flags);
  64         } while (ret == -1 && (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK));
  65
  66         return ret;
  67 }
  68
  69 /*******************************************************************
  70 A recvfrom wrapper that will deal with EINTR.
  71 NB. As used with non-blocking sockets, return on EAGAIN/EWOULDBLOCK
  72 ********************************************************************/
  73
  74 ssize_t sys_recvfrom(int s, void *buf, size_t len, int flags, struct sockaddr *from, socklen_t *fromlen)
  75 {
  76         ssize_t ret;
  77
  78         do {
  79                 ret = recvfrom(s, buf, len, flags, from, fromlen);
  80         } while (ret == -1 && (errno == EINTR));
  81         return ret;
  82 }
  83
  84 /*******************************************************************
  85 A fcntl wrapper that will deal with EINTR.
  86 ********************************************************************/
  87
  88 int sys_fcntl_ptr(int fd, int cmd, void *arg)
  89 {
  90         int ret;
  91
  92         do {
  93                 ret = fcntl(fd, cmd, arg);
  94         } while (ret == -1 && errno == EINTR);
  95         return ret;
  96 }
  97
  98 /*******************************************************************
  99 A fcntl wrapper that will deal with EINTR.
 100 ********************************************************************/
 101
 102 int sys_fcntl_long(int fd, int cmd, long arg)
 103 {
 104         int ret;
 105
 106         do {
 107                 ret = fcntl(fd, cmd, arg);
 108         } while (ret == -1 && errno == EINTR);
 109         return ret;
 110 }
 111
 112 /*******************************************************************
 113 A fcntl wrapper that will deal with EINTR.
 114 ********************************************************************/
 115
 116 int sys_fcntl_int(int fd, int cmd, int arg)
 117 {
 118         int ret;
 119
 120         do {
 121                 ret = fcntl(fd, cmd, arg);
 122         } while (ret == -1 && errno == EINTR);
 123         return ret;
 124 }
 125
 126 /****************************************************************************
 127  Return the best approximation to a 'create time' under UNIX from a stat
 128  structure.
 129 ****************************************************************************/
 130
 131 static struct timespec calc_create_time_stat(const struct stat *st)
 132 {
 133         struct timespec ret, ret1;
 134         struct timespec c_time = get_ctimespec(st);
 135         struct timespec m_time = get_mtimespec(st);
 136         struct timespec a_time = get_atimespec(st);
 137
 138         ret = timespec_compare(&c_time, &m_time) < 0 ? c_time : m_time;
 139         ret1 = timespec_compare(&ret, &a_time) < 0 ? ret : a_time;
 140
 141         if(!null_timespec(ret1)) {
 142                 return ret1;
 143         }
 144
 145         /*
 146          * One of ctime, mtime or atime was zero (probably atime).
 147          * Just return MIN(ctime, mtime).
 148          */
 149         return ret;
 150 }
 151
 152 /****************************************************************************
 153  Return the best approximation to a 'create time' under UNIX from a stat_ex
 154  structure.
 155 ****************************************************************************/
 156
 157 static struct timespec calc_create_time_stat_ex(const struct stat_ex *st)
 158 {
 159         struct timespec ret, ret1;
 160         struct timespec c_time = st->st_ex_ctime;
 161         struct timespec m_time = st->st_ex_mtime;
 162         struct timespec a_time = st->st_ex_atime;
 163
 164         ret = timespec_compare(&c_time, &m_time) < 0 ? c_time : m_time;
 165         ret1 = timespec_compare(&ret, &a_time) < 0 ? ret : a_time;
 166
 167         if(!null_timespec(ret1)) {
 168                 return ret1;
 169         }
 170
 171         /*
 172          * One of ctime, mtime or atime was zero (probably atime).
 173          * Just return MIN(ctime, mtime).
 174          */
 175         return ret;
 176 }
 177
 178 /****************************************************************************
 179  Return the 'create time' from a stat struct if it exists (birthtime) or else
 180  use the best approximation.
 181 ****************************************************************************/
 182
 183 static void make_create_timespec(const struct stat *pst, struct stat_ex *dst,
 184                                  bool fake_dir_create_times)
 185 {
 186         if (S_ISDIR(pst->st_mode) && fake_dir_create_times) {
 187                 dst->st_ex_btime.tv_sec = 315493200L;          /* 1/1/1980 */
 188                 dst->st_ex_btime.tv_nsec = 0;
 189         }
 190
 191         dst->st_ex_iflags &= ~ST_EX_IFLAG_CALCULATED_BTIME;
 192
 193 #if defined(HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC)
 194         dst->st_ex_btime = pst->st_birthtimespec;
 195 #elif defined(HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC)
 196         dst->st_ex_btime.tv_sec = pst->st_birthtime;
 197         dst->st_ex_btime.tv_nsec = pst->st_birthtimenspec;
 198 #elif defined(HAVE_STRUCT_STAT_ST_BIRTHTIME)
 199         dst->st_ex_btime.tv_sec = pst->st_birthtime;
 200         dst->st_ex_btime.tv_nsec = 0;
 201 #else
 202         dst->st_ex_btime = calc_create_time_stat(pst);
 203         dst->st_ex_iflags |= ST_EX_IFLAG_CALCULATED_BTIME;
 204 #endif
 205
 206         /* Deal with systems that don't initialize birthtime correctly.
 207          * Pointed out by SATOH Fumiyasu <fumiyas@osstech.jp>.
 208          */
 209         if (null_timespec(dst->st_ex_btime)) {
 210                 dst->st_ex_btime = calc_create_time_stat(pst);
 211                 dst->st_ex_iflags |= ST_EX_IFLAG_CALCULATED_BTIME;
 212         }
 213 }
 214
 215 /****************************************************************************
 216  If we update a timestamp in a stat_ex struct we may have to recalculate
 217  the birthtime. For now only implement this for write time, but we may
 218  also need to do it for atime and ctime. JRA.
 219 ****************************************************************************/
 220
 221 void update_stat_ex_mtime(struct stat_ex *dst,
 222                                 struct timespec write_ts)
 223 {
 224         dst->st_ex_mtime = write_ts;
 225
 226         /* We may have to recalculate btime. */
 227         if (dst->st_ex_iflags & ST_EX_IFLAG_CALCULATED_BTIME) {
 228                 dst->st_ex_btime = calc_create_time_stat_ex(dst);
 229         }
 230 }
 231
 232 void update_stat_ex_create_time(struct stat_ex *dst,
 233                                 struct timespec create_time)
 234 {
 235         dst->st_ex_btime = create_time;
 236         dst->st_ex_iflags &= ~ST_EX_IFLAG_CALCULATED_BTIME;
 237 }
 238
 239 void update_stat_ex_from_saved_stat(struct stat_ex *dst,
 240                                     const struct stat_ex *src)
 241 {
 242         if (!VALID_STAT(*src)) {
 243                 return;
 244         }
 245
 246         if (!(src->st_ex_iflags & ST_EX_IFLAG_CALCULATED_BTIME)) {
 247                 update_stat_ex_create_time(dst, src->st_ex_btime);
 248         }
 249 }
 250
 251 void init_stat_ex_from_stat (struct stat_ex *dst,
 252                             const struct stat *src,
 253                             bool fake_dir_create_times)
 254 {
 255         dst->st_ex_dev = src->st_dev;
 256         dst->st_ex_ino = src->st_ino;
 257         dst->st_ex_mode = src->st_mode;
 258         dst->st_ex_nlink = src->st_nlink;
 259         dst->st_ex_uid = src->st_uid;
 260         dst->st_ex_gid = src->st_gid;
 261         dst->st_ex_rdev = src->st_rdev;
 262         dst->st_ex_size = src->st_size;
 263         dst->st_ex_atime = get_atimespec(src);
 264         dst->st_ex_mtime = get_mtimespec(src);
 265         dst->st_ex_ctime = get_ctimespec(src);
 266         dst->st_ex_iflags = 0;
 267         make_create_timespec(src, dst, fake_dir_create_times);
 268 #ifdef HAVE_STAT_ST_BLKSIZE
 269         dst->st_ex_blksize = src->st_blksize;
 270 #else
 271         dst->st_ex_blksize = STAT_ST_BLOCKSIZE;
 272 #endif
 273
 274 #ifdef HAVE_STAT_ST_BLOCKS
 275         dst->st_ex_blocks = src->st_blocks;
 276 #else
 277         dst->st_ex_blocks = src->st_size / dst->st_ex_blksize + 1;
 278 #endif
 279
 280 #ifdef HAVE_STAT_ST_FLAGS
 281         dst->st_ex_flags = src->st_flags;
 282 #else
 283         dst->st_ex_flags = 0;
 284 #endif
 285 }
 286
 287 /*******************************************************************
 288 A stat() wrapper.
 289 ********************************************************************/
 290
 291 int sys_stat(const char *fname, SMB_STRUCT_STAT *sbuf,
 292              bool fake_dir_create_times)
 293 {
 294         int ret;
 295         struct stat statbuf;
 296         ret = stat(fname, &statbuf);
 297         if (ret == 0) {
 298                 /* we always want directories to appear zero size */
 299                 if (S_ISDIR(statbuf.st_mode)) {
 300                         statbuf.st_size = 0;
 301                 }
 302                 init_stat_ex_from_stat(sbuf, &statbuf, fake_dir_create_times);
 303         }
 304         return ret;
 305 }
 306
 307 /*******************************************************************
 308  An fstat() wrapper.
 309 ********************************************************************/
 310
 311 int sys_fstat(int fd, SMB_STRUCT_STAT *sbuf, bool fake_dir_create_times)
 312 {
 313         int ret;
 314         struct stat statbuf;
 315         ret = fstat(fd, &statbuf);
 316         if (ret == 0) {
 317                 /* we always want directories to appear zero size */
 318                 if (S_ISDIR(statbuf.st_mode)) {
 319                         statbuf.st_size = 0;
 320                 }
 321                 init_stat_ex_from_stat(sbuf, &statbuf, fake_dir_create_times);
 322         }
 323         return ret;
 324 }
 325
 326 /*******************************************************************
 327  An lstat() wrapper.
 328 ********************************************************************/
 329
 330 int sys_lstat(const char *fname,SMB_STRUCT_STAT *sbuf,
 331               bool fake_dir_create_times)
 332 {
 333         int ret;
 334         struct stat statbuf;
 335         ret = lstat(fname, &statbuf);
 336         if (ret == 0) {
 337                 /* we always want directories to appear zero size */
 338                 if (S_ISDIR(statbuf.st_mode)) {
 339                         statbuf.st_size = 0;
 340                 }
 341                 init_stat_ex_from_stat(sbuf, &statbuf, fake_dir_create_times);
 342         }
 343         return ret;
 344 }
 345
 346 /*******************************************************************
 347  An fstatat() wrapper.
 348 ********************************************************************/
 349
 350 int sys_fstatat(int fd,
 351                 const char *pathname,
 352                 SMB_STRUCT_STAT *sbuf,
 353                 int flags,
 354                 bool fake_dir_create_times)
 355 {
 356         int ret;
 357         struct stat statbuf;
 358
 359         ret = fstatat(fd, pathname, &statbuf, flags);
 360         if (ret != 0) {
 361                 return -1;
 362         }
 363
 364         /* we always want directories to appear zero size */
 365         if (S_ISDIR(statbuf.st_mode)) {
 366                 statbuf.st_size = 0;
 367         }
 368         init_stat_ex_from_stat(sbuf, &statbuf, fake_dir_create_times);
 369         return 0;
 370 }
 371
 372 /*******************************************************************
 373  An posix_fallocate() wrapper.
 374 ********************************************************************/
 375 int sys_posix_fallocate(int fd, off_t offset, off_t len)
 376 {
 377 #if defined(HAVE_POSIX_FALLOCATE)
 378         return posix_fallocate(fd, offset, len);
 379 #elif defined(F_RESVSP64)
 380         /* this handles XFS on IRIX */
 381         struct flock64 fl;
 382         off_t new_len = offset + len;
 383         int ret;
 384         struct stat64 sbuf;
 385
 386         /* unlikely to get a too large file on a 64bit system but ... */
 387         if (new_len < 0)
 388                 return EFBIG;
 389
 390         fl.l_whence = SEEK_SET;
 391         fl.l_start = offset;
 392         fl.l_len = len;
 393
 394         ret=fcntl(fd, F_RESVSP64, &fl);
 395
 396         if (ret != 0)
 397                 return errno;
 398
 399         /* Make sure the file gets enlarged after we allocated space: */
 400         fstat64(fd, &sbuf);
 401         if (new_len > sbuf.st_size)
 402                 ftruncate64(fd, new_len);
 403         return 0;
 404 #else
 405         return ENOSYS;
 406 #endif
 407 }
 408
 409 /*******************************************************************
 410  An fallocate() function that matches the semantics of the Linux one.
 411 ********************************************************************/
 412
 413 #ifdef HAVE_LINUX_FALLOC_H
 414 #include <linux/falloc.h>
 415 #endif
 416
 417 int sys_fallocate(int fd, uint32_t mode, off_t offset, off_t len)
 418 {
 419 #if defined(HAVE_LINUX_FALLOCATE)
 420         int lmode = 0;
 421
 422         if (mode & VFS_FALLOCATE_FL_KEEP_SIZE) {
 423                 lmode |= FALLOC_FL_KEEP_SIZE;
 424                 mode &= ~VFS_FALLOCATE_FL_KEEP_SIZE;
 425         }
 426
 427 #if defined(HAVE_FALLOC_FL_PUNCH_HOLE)
 428         if (mode & VFS_FALLOCATE_FL_PUNCH_HOLE) {
 429                 lmode |= FALLOC_FL_PUNCH_HOLE;
 430                 mode &= ~VFS_FALLOCATE_FL_PUNCH_HOLE;
 431         }
 432 #endif  /* HAVE_FALLOC_FL_PUNCH_HOLE */
 433
 434         if (mode != 0) {
 435                 DEBUG(2, ("unmapped fallocate flags: %lx\n",
 436                       (unsigned long)mode));
 437                 errno = EINVAL;
 438                 return -1;
 439         }
 440         return fallocate(fd, lmode, offset, len);
 441 #else   /* HAVE_LINUX_FALLOCATE */
 442         /* TODO - plumb in fallocate from other filesysetms like VXFS etc. JRA. */
 443         errno = ENOSYS;
 444         return -1;
 445 #endif  /* HAVE_LINUX_FALLOCATE */
 446 }
 447
 448 /*******************************************************************
 449  An fdopendir wrapper.
 450 ********************************************************************/
 451
 452 DIR *sys_fdopendir(int fd)
 453 {
 454 #if defined(HAVE_FDOPENDIR)
 455         return fdopendir(fd);
 456 #else
 457         errno = ENOSYS;
 458         return NULL;
 459 #endif
 460 }
 461
 462 /*******************************************************************
 463  An mknod() wrapper.
 464 ********************************************************************/
 465
 466 int sys_mknod(const char *path, mode_t mode, SMB_DEV_T dev)
 467 {
 468 #if defined(HAVE_MKNOD)
 469         return mknod(path, mode, dev);
 470 #else
 471         /* No mknod system call. */
 472         errno = ENOSYS;
 473         return -1;
 474 #endif
 475 }
 476
 477 /*******************************************************************
 478  A mknodat() wrapper.
 479 ********************************************************************/
 480
 481 int sys_mknodat(int dirfd, const char *path, mode_t mode, SMB_DEV_T dev)
 482 {
 483 #if defined(HAVE_MKNODAT)
 484         return mknodat(dirfd, path, mode, dev);
 485 #else
 486         /* No mknod system call. */
 487         errno = ENOSYS;
 488         return -1;
 489 #endif
 490 }
 491
 492 /*******************************************************************
 493  System wrapper for getwd. Always returns MALLOC'ed memory, or NULL
 494  on error (malloc fail usually).
 495 ********************************************************************/
 496
 497 char *sys_getwd(void)
 498 {
 499 #ifdef GETCWD_TAKES_NULL
 500         return getcwd(NULL, 0);
 501 #elif defined(HAVE_GETCWD)
 502         char *wd = NULL, *s = NULL;
 503         size_t allocated = PATH_MAX;
 504
 505         while (1) {
 506                 s = SMB_REALLOC_ARRAY(s, char, allocated);
 507                 if (s == NULL) {
 508                         return NULL;
 509                 }
 510                 wd = getcwd(s, allocated);
 511                 if (wd) {
 512                         break;
 513                 }
 514                 if (errno != ERANGE) {
 515                         int saved_errno = errno;
 516                         SAFE_FREE(s);
 517                         errno = saved_errno;
 518                         break;
 519                 }
 520                 allocated *= 2;
 521                 if (allocated < PATH_MAX) {
 522                         SAFE_FREE(s);
 523                         break;
 524                 }
 525         }
 526         return wd;
 527 #else
 528         char *wd = NULL;
 529         char *s = SMB_MALLOC_ARRAY(char, PATH_MAX);
 530         if (s == NULL) {
 531                 return NULL;
 532         }
 533         wd = getwd(s);
 534         if (wd == NULL) {
 535                 int saved_errno = errno;
 536                 SAFE_FREE(s);
 537                 errno = saved_errno;
 538         }
 539         return wd;
 540 #endif
 541 }
 542
 543 #if defined(HAVE_POSIX_CAPABILITIES)
 544
 545 /**************************************************************************
 546  Try and abstract process capabilities (for systems that have them).
 547 ****************************************************************************/
 548
 549 /* Set the POSIX capabilities needed for the given purpose into the effective
 550  * capability set of the current process. Make sure they are always removed
 551  * from the inheritable set, because there is no circumstance in which our
 552  * children should inherit our elevated privileges.
 553  */
 554 static bool set_process_capability(enum smbd_capability capability,
 555                                    bool enable)
 556 {
 557         /* "5" is the number of "num_cap_vals++" below */
 558         cap_value_t cap_vals[5] = {0};
 559         size_t num_cap_vals = 0;
 560
 561         cap_t cap;
 562
 563 #if defined(HAVE_PRCTL) && defined(PR_GET_KEEPCAPS) && defined(PR_SET_KEEPCAPS)
 564         /* On Linux, make sure that any capabilities we grab are sticky
 565          * across UID changes. We expect that this would allow us to keep both
 566          * the effective and permitted capability sets, but as of circa 2.6.16,
 567          * only the permitted set is kept. It is a bug (which we work around)
 568          * that the effective set is lost, but we still require the effective
 569          * set to be kept.
 570          */
 571         if (!prctl(PR_GET_KEEPCAPS)) {
 572                 prctl(PR_SET_KEEPCAPS, 1);
 573         }
 574 #endif
 575
 576         cap = cap_get_proc();
 577         if (cap == NULL) {
 578                 DEBUG(0,("set_process_capability: cap_get_proc failed: %s\n",
 579                         strerror(errno)));
 580                 return False;
 581         }
 582
 583         switch (capability) {
 584                 /*
 585                  * WARNING: If you add any #ifdef for a fresh
 586                  * capability, bump up the array size in the
 587                  * declaration of cap_vals[] above just to be
 588                  * trivially safe to never overwrite cap_vals[].
 589                  */
 590                 case KERNEL_OPLOCK_CAPABILITY:
 591 #ifdef CAP_NETWORK_MGT
 592                         /* IRIX has CAP_NETWORK_MGT for oplocks. */
 593                         cap_vals[num_cap_vals++] = CAP_NETWORK_MGT;
 594 #endif
 595                         break;
 596                 case DMAPI_ACCESS_CAPABILITY:
 597 #ifdef CAP_DEVICE_MGT
 598                         /* IRIX has CAP_DEVICE_MGT for DMAPI access. */
 599                         cap_vals[num_cap_vals++] = CAP_DEVICE_MGT;
 600 #elif CAP_MKNOD
 601                         /* Linux has CAP_MKNOD for DMAPI access. */
 602                         cap_vals[num_cap_vals++] = CAP_MKNOD;
 603 #endif
 604                         break;
 605                 case LEASE_CAPABILITY:
 606 #ifdef CAP_LEASE
 607                         cap_vals[num_cap_vals++] = CAP_LEASE;
 608 #endif
 609                         break;
 610                 case DAC_OVERRIDE_CAPABILITY:
 611 #ifdef CAP_DAC_OVERRIDE
 612                         cap_vals[num_cap_vals++] = CAP_DAC_OVERRIDE;
 613 #endif
 614         }
 615
 616         if (num_cap_vals == 0) {
 617                 cap_free(cap);
 618                 return True;
 619         }
 620
 621         cap_set_flag(cap, CAP_EFFECTIVE, num_cap_vals, cap_vals,
 622                 enable ? CAP_SET : CAP_CLEAR);
 623
 624         /* We never want to pass capabilities down to our children, so make
 625          * sure they are not inherited.
 626          */
 627         cap_set_flag(cap, CAP_INHERITABLE, num_cap_vals, cap_vals, CAP_CLEAR);
 628
 629         if (cap_set_proc(cap) == -1) {
 630                 DEBUG(0, ("set_process_capability: cap_set_proc failed: %s\n",
 631                         strerror(errno)));
 632                 cap_free(cap);
 633                 return False;
 634         }
 635
 636         cap_free(cap);
 637         return True;
 638 }
 639
 640 #endif /* HAVE_POSIX_CAPABILITIES */
 641
 642 /****************************************************************************
 643  Gain the oplock capability from the kernel if possible.
 644 ****************************************************************************/
 645
 646 void set_effective_capability(enum smbd_capability capability)
 647 {
 648 #if defined(HAVE_POSIX_CAPABILITIES)
 649         set_process_capability(capability, True);
 650 #endif /* HAVE_POSIX_CAPABILITIES */
 651 }
 652
 653 void drop_effective_capability(enum smbd_capability capability)
 654 {
 655 #if defined(HAVE_POSIX_CAPABILITIES)
 656         set_process_capability(capability, False);
 657 #endif /* HAVE_POSIX_CAPABILITIES */
 658 }
 659
 660 /**************************************************************************
 661  Wrapper for random().
 662 ****************************************************************************/
 663
 664 long sys_random(void)
 665 {
 666 #if defined(HAVE_RANDOM)
 667         return (long)random();
 668 #elif defined(HAVE_RAND)
 669         return (long)rand();
 670 #else
 671         DEBUG(0,("Error - no random function available !\n"));
 672         exit(1);
 673 #endif
 674 }
 675
 676 /**************************************************************************
 677  Wrapper for srandom().
 678 ****************************************************************************/
 679
 680 void sys_srandom(unsigned int seed)
 681 {
 682 #if defined(HAVE_SRANDOM)
 683         srandom(seed);
 684 #elif defined(HAVE_SRAND)
 685         srand(seed);
 686 #else
 687         DEBUG(0,("Error - no srandom function available !\n"));
 688         exit(1);
 689 #endif
 690 }
 691
 692 #ifndef NGROUPS_MAX
 693 #define NGROUPS_MAX 32 /* Guess... */
 694 #endif
 695
 696 /**************************************************************************
 697  Returns equivalent to NGROUPS_MAX - using sysconf if needed.
 698 ****************************************************************************/
 699
 700 int setgroups_max(void)
 701 {
 702 #if defined(SYSCONF_SC_NGROUPS_MAX)
 703         int ret = sysconf(_SC_NGROUPS_MAX);
 704         return (ret == -1) ? NGROUPS_MAX : ret;
 705 #else
 706         return NGROUPS_MAX;
 707 #endif
 708 }
 709
 710 int getgroups_max(void)
 711 {
 712 #if defined(DARWINOS)
 713         /*
 714          * On MacOS sysconf(_SC_NGROUPS_MAX) returns 16 due to MacOS's group
 715          * nesting. However, The initgroups() manpage states the following:
 716          * "Note that OS X supports group membership in an unlimited number
 717          * of groups. The OS X kernel uses the group list stored in the process
 718          * credentials only as an initial cache.  Additional group memberships
 719          * are determined by communication between the operating system and the
 720          * opendirectoryd daemon."
 721          */
 722         return INT_MAX;
 723 #else
 724         return setgroups_max();
 725 #endif
 726 }
 727
 728 /**************************************************************************
 729  Wrap setgroups and getgroups for systems that declare getgroups() as
 730  returning an array of gid_t, but actually return an array of int.
 731 ****************************************************************************/
 732
 733 #if defined(HAVE_BROKEN_GETGROUPS)
 734
 735 #ifdef HAVE_BROKEN_GETGROUPS
 736 #define GID_T int
 737 #else
 738 #define GID_T gid_t
 739 #endif
 740
 741 static int sys_broken_getgroups(int setlen, gid_t *gidset)
 742 {
 743         GID_T *group_list;
 744         int i, ngroups;
 745
 746         if(setlen == 0) {
 747                 return getgroups(0, NULL);
 748         }
 749
 750         /*
 751          * Broken case. We need to allocate a
 752          * GID_T array of size setlen.
 753          */
 754
 755         if(setlen < 0) {
 756                 errno = EINVAL;
 757                 return -1;
 758         }
 759
 760         if((group_list = SMB_MALLOC_ARRAY(GID_T, setlen)) == NULL) {
 761                 DEBUG(0,("sys_getgroups: Malloc fail.\n"));
 762                 return -1;
 763         }
 764
 765         if((ngroups = getgroups(setlen, group_list)) < 0) {
 766                 int saved_errno = errno;
 767                 SAFE_FREE(group_list);
 768                 errno = saved_errno;
 769                 return -1;
 770         }
 771
 772         /*
 773          * We're safe here as if ngroups > setlen then
 774          * getgroups *must* return EINVAL.
 775          * pubs.opengroup.org/onlinepubs/009695399/functions/getgroups.html
 776          */
 777
 778         for(i = 0; i < ngroups; i++)
 779                 gidset[i] = (gid_t)group_list[i];
 780
 781         SAFE_FREE(group_list);
 782         return ngroups;
 783 }
 784
 785 static int sys_broken_setgroups(int setlen, gid_t *gidset)
 786 {
 787         GID_T *group_list;
 788         int i ;
 789
 790         if (setlen == 0)
 791                 return 0 ;
 792
 793         if (setlen < 0 || setlen > setgroups_max()) {
 794                 errno = EINVAL;
 795                 return -1;
 796         }
 797
 798         /*
 799          * Broken case. We need to allocate a
 800          * GID_T array of size setlen.
 801          */
 802
 803         if((group_list = SMB_MALLOC_ARRAY(GID_T, setlen)) == NULL) {
 804                 DEBUG(0,("sys_setgroups: Malloc fail.\n"));
 805                 return -1;
 806         }
 807
 808         for(i = 0; i < setlen; i++)
 809                 group_list[i] = (GID_T) gidset[i];
 810
 811         if(samba_setgroups(setlen, group_list) != 0) {
 812                 int saved_errno = errno;
 813                 SAFE_FREE(group_list);
 814                 errno = saved_errno;
 815                 return -1;
 816         }
 817
 818         SAFE_FREE(group_list);
 819         return 0 ;
 820 }
 821
 822 #endif /* HAVE_BROKEN_GETGROUPS */
 823
 824 /* This is a list of systems that require the first GID passed to setgroups(2)
 825  * to be the effective GID. If your system is one of these, add it here.
 826  */
 827 #if defined (FREEBSD) || defined (DARWINOS)
 828 #define USE_BSD_SETGROUPS
 829 #endif
 830
 831 #if defined(USE_BSD_SETGROUPS)
 832 /* Depending on the particular BSD implementation, the first GID that is
 833  * passed to setgroups(2) will either be ignored or will set the credential's
 834  * effective GID. In either case, the right thing to do is to guarantee that
 835  * gidset[0] is the effective GID.
 836  */
 837 static int sys_bsd_setgroups(gid_t primary_gid, int setlen, const gid_t *gidset)
 838 {
 839         gid_t *new_gidset = NULL;
 840         int max;
 841         int ret;
 842
 843         /* setgroups(2) will fail with EINVAL if we pass too many groups. */
 844         max = setgroups_max();
 845
 846         /* No group list, just make sure we are setting the effective GID. */
 847         if (setlen == 0) {
 848                 return samba_setgroups(1, &primary_gid);
 849         }
 850
 851         /* If the primary gid is not the first array element, grow the array
 852          * and insert it at the front.
 853          */
 854         if (gidset[0] != primary_gid) {
 855                 new_gidset = SMB_MALLOC_ARRAY(gid_t, setlen + 1);
 856                 if (new_gidset == NULL) {
 857                         return -1;
 858                 }
 859
 860                 memcpy(new_gidset + 1, gidset, (setlen * sizeof(gid_t)));
 861                 new_gidset[0] = primary_gid;
 862                 setlen++;
 863         }
 864
 865         if (setlen > max) {
 866                 DEBUG(3, ("forced to truncate group list from %d to %d\n",
 867                         setlen, max));
 868                 setlen = max;
 869         }
 870
 871 #if defined(HAVE_BROKEN_GETGROUPS)
 872         ret = sys_broken_setgroups(setlen, new_gidset ? new_gidset : gidset);
 873 #else
 874         ret = samba_setgroups(setlen, new_gidset ? new_gidset : gidset);
 875 #endif
 876
 877         if (new_gidset) {
 878                 int errsav = errno;
 879                 SAFE_FREE(new_gidset);
 880                 errno = errsav;
 881         }
 882
 883         return ret;
 884 }
 885
 886 #endif /* USE_BSD_SETGROUPS */
 887
 888 /**************************************************************************
 889  Wrapper for getgroups. Deals with broken (int) case.
 890 ****************************************************************************/
 891
 892 int sys_getgroups(int setlen, gid_t *gidset)
 893 {
 894 #if defined(HAVE_BROKEN_GETGROUPS)
 895         return sys_broken_getgroups(setlen, gidset);
 896 #else
 897         return getgroups(setlen, gidset);
 898 #endif
 899 }
 900
 901 /**************************************************************************
 902  Wrapper for setgroups. Deals with broken (int) case and BSD case.
 903 ****************************************************************************/
 904
 905 int sys_setgroups(gid_t UNUSED(primary_gid), int setlen, gid_t *gidset)
 906 {
 907 #if !defined(HAVE_SETGROUPS)
 908         errno = ENOSYS;
 909         return -1;
 910 #endif /* HAVE_SETGROUPS */
 911
 912 #if defined(USE_BSD_SETGROUPS)
 913         return sys_bsd_setgroups(primary_gid, setlen, gidset);
 914 #elif defined(HAVE_BROKEN_GETGROUPS)
 915         return sys_broken_setgroups(setlen, gidset);
 916 #else
 917         return samba_setgroups(setlen, gidset);
 918 #endif
 919 }
 920
 921 /****************************************************************************
 922  Return the major devicenumber for UNIX extensions.
 923 ****************************************************************************/
 924
 925 uint32_t unix_dev_major(SMB_DEV_T dev)
 926 {
 927 #if defined(HAVE_DEVICE_MAJOR_FN)
 928         return (uint32_t)major(dev);
 929 #else
 930         return (uint32_t)(dev >> 8);
 931 #endif
 932 }
 933
 934 /****************************************************************************
 935  Return the minor devicenumber for UNIX extensions.
 936 ****************************************************************************/
 937
 938 uint32_t unix_dev_minor(SMB_DEV_T dev)
 939 {
 940 #if defined(HAVE_DEVICE_MINOR_FN)
 941         return (uint32_t)minor(dev);
 942 #else
 943         return (uint32_t)(dev & 0xff);
 944 #endif
 945 }
 946
 947 /**************************************************************************
 948  Wrapper for realpath.
 949 ****************************************************************************/
 950
 951 char *sys_realpath(const char *path)
 952 {
 953         char *result;
 954
 955 #ifdef REALPATH_TAKES_NULL
 956         result = realpath(path, NULL);
 957 #else
 958         result = SMB_MALLOC_ARRAY(char, PATH_MAX + 1);
 959         if (result) {
 960                 char *resolved_path = realpath(path, result);
 961                 if (!resolved_path) {
 962                         SAFE_FREE(result);
 963                 } else {
 964                         /* SMB_ASSERT(result == resolved_path) ? */
 965                         result = resolved_path;
 966                 }
 967         }
 968 #endif
 969         return result;
 970 }
 971
 972 #if 0
 973 /*******************************************************************
 974  Return the number of CPUs.
 975 ********************************************************************/
 976
 977 int sys_get_number_of_cores(void)
 978 {
 979         int ret = -1;
 980
 981 #if defined(HAVE_SYSCONF)
 982 #if defined(_SC_NPROCESSORS_ONLN)
 983         ret = (int)sysconf(_SC_NPROCESSORS_ONLN);
 984 #endif
 985 #if defined(_SC_NPROCESSORS_CONF)
 986         if (ret < 1) {
 987                 ret = (int)sysconf(_SC_NPROCESSORS_CONF);
 988         }
 989 #endif
 990 #elif defined(HAVE_SYSCTL) && defined(CTL_HW)
 991         int name[2];
 992         unsigned int len = sizeof(ret);
 993
 994         name[0] = CTL_HW;
 995 #if defined(HW_AVAILCPU)
 996         name[1] = HW_AVAILCPU;
 997
 998         if (sysctl(name, 2, &ret, &len, NULL, 0) == -1) {
 999                 ret = -1;
1000         }
1001 #endif
1002 #if defined(HW_NCPU)
1003         if(ret < 1) {
1004                 name[0] = CTL_HW;
1005                 name[1] = HW_NCPU;
1006                 if (sysctl(nm, 2, &count, &len, NULL, 0) == -1) {
1007                         ret = -1;
1008                 }
1009         }
1010 #endif
1011 #endif
1012         if (ret < 1) {
1013                 ret = 1;
1014         }
1015         return ret;
1016 }
1017 #endif
1018
1019 static struct proc_fd_pattern {
1020         const char *pattern;
1021         const char *test_path;
1022 } proc_fd_patterns[] = {
1023         /* Linux */
1024         { "/proc/self/fd/%d", "/proc/self/fd/0" },
1025         { NULL, NULL },
1026 };
1027
1028 static const char *proc_fd_pattern;
1029
1030 bool sys_have_proc_fds(void)
1031 {
1032         static bool checked;
1033         static bool have_proc_fds;
1034         struct proc_fd_pattern *p = NULL;
1035         struct stat sb;
1036         int ret;
1037
1038         if (checked) {
1039                 return have_proc_fds;
1040         }
1041
1042         for (p = &proc_fd_patterns[0]; p->test_path != NULL; p++) {
1043                 ret = stat(p->test_path, &sb);
1044                 if (ret != 0) {
1045                         continue;
1046                 }
1047                 have_proc_fds = true;
1048                 proc_fd_pattern = p->pattern;
1049                 break;
1050         }
1051
1052         checked = true;
1053         return have_proc_fds;
1054 }
1055
1056 const char *sys_proc_fd_path(int fd, char *buf, size_t bufsize)
1057 {
1058         int written;
1059
1060         if (!sys_have_proc_fds()) {
1061                 return NULL;
1062         }
1063
1064 #if defined(__clang__)
1065 #pragma clang diagnostic push
1066 #pragma clang diagnostic ignored "-Wformat-nonliteral"
1067 #endif
1068         written = snprintf(buf,
1069                            bufsize,
1070                            proc_fd_pattern,
1071                            fd);
1072 #if defined(__clang__)
1073 #pragma clang diagnostic pop
1074 #endif
1075         if (written >= bufsize) {
1076                 return NULL;
1077         }
1078
1079         return buf;
1080 }