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