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 *wd = NULL;
 609         char *s = SMB_MALLOC_ARRAY(char, PATH_MAX);
 610         if (s == NULL) {
 611                 return NULL;
 612         }
 613         wd = getwd(s);
 614         if (wd == NULL) {
 615                 SAFE_FREE(s);
 616         }
 617         return wd;
 618 #endif
 619 }
 620
 621 #if defined(HAVE_POSIX_CAPABILITIES)
 622
 623 /**************************************************************************
 624  Try and abstract process capabilities (for systems that have them).
 625 ****************************************************************************/
 626
 627 /* Set the POSIX capabilities needed for the given purpose into the effective
 628  * capability set of the current process. Make sure they are always removed
 629  * from the inheritable set, because there is no circumstance in which our
 630  * children should inherit our elevated privileges.
 631  */
 632 static bool set_process_capability(enum smbd_capability capability,
 633                                    bool enable)
 634 {
 635         cap_value_t cap_vals[2] = {0};
 636         int num_cap_vals = 0;
 637
 638         cap_t cap;
 639
 640 #if defined(HAVE_PRCTL) && defined(PR_GET_KEEPCAPS) && defined(PR_SET_KEEPCAPS)
 641         /* On Linux, make sure that any capabilities we grab are sticky
 642          * across UID changes. We expect that this would allow us to keep both
 643          * the effective and permitted capability sets, but as of circa 2.6.16,
 644          * only the permitted set is kept. It is a bug (which we work around)
 645          * that the effective set is lost, but we still require the effective
 646          * set to be kept.
 647          */
 648         if (!prctl(PR_GET_KEEPCAPS)) {
 649                 prctl(PR_SET_KEEPCAPS, 1);
 650         }
 651 #endif
 652
 653         cap = cap_get_proc();
 654         if (cap == NULL) {
 655                 DEBUG(0,("set_process_capability: cap_get_proc failed: %s\n",
 656                         strerror(errno)));
 657                 return False;
 658         }
 659
 660         switch (capability) {
 661                 case KERNEL_OPLOCK_CAPABILITY:
 662 #ifdef CAP_NETWORK_MGT
 663                         /* IRIX has CAP_NETWORK_MGT for oplocks. */
 664                         cap_vals[num_cap_vals++] = CAP_NETWORK_MGT;
 665 #endif
 666                         break;
 667                 case DMAPI_ACCESS_CAPABILITY:
 668 #ifdef CAP_DEVICE_MGT
 669                         /* IRIX has CAP_DEVICE_MGT for DMAPI access. */
 670                         cap_vals[num_cap_vals++] = CAP_DEVICE_MGT;
 671 #elif CAP_MKNOD
 672                         /* Linux has CAP_MKNOD for DMAPI access. */
 673                         cap_vals[num_cap_vals++] = CAP_MKNOD;
 674 #endif
 675                         break;
 676                 case LEASE_CAPABILITY:
 677 #ifdef CAP_LEASE
 678                         cap_vals[num_cap_vals++] = CAP_LEASE;
 679 #endif
 680                         break;
 681                 case DAC_OVERRIDE_CAPABILITY:
 682 #ifdef CAP_DAC_OVERRIDE
 683                         cap_vals[num_cap_vals++] = CAP_DAC_OVERRIDE;
 684 #endif
 685         }
 686
 687         SMB_ASSERT(num_cap_vals <= ARRAY_SIZE(cap_vals));
 688
 689         if (num_cap_vals == 0) {
 690                 cap_free(cap);
 691                 return True;
 692         }
 693
 694         cap_set_flag(cap, CAP_EFFECTIVE, num_cap_vals, cap_vals,
 695                 enable ? CAP_SET : CAP_CLEAR);
 696
 697         /* We never want to pass capabilities down to our children, so make
 698          * sure they are not inherited.
 699          */
 700         cap_set_flag(cap, CAP_INHERITABLE, num_cap_vals, cap_vals, CAP_CLEAR);
 701
 702         if (cap_set_proc(cap) == -1) {
 703                 DEBUG(0, ("set_process_capability: cap_set_proc failed: %s\n",
 704                         strerror(errno)));
 705                 cap_free(cap);
 706                 return False;
 707         }
 708
 709         cap_free(cap);
 710         return True;
 711 }
 712
 713 #endif /* HAVE_POSIX_CAPABILITIES */
 714
 715 /****************************************************************************
 716  Gain the oplock capability from the kernel if possible.
 717 ****************************************************************************/
 718
 719 void set_effective_capability(enum smbd_capability capability)
 720 {
 721 #if defined(HAVE_POSIX_CAPABILITIES)
 722         set_process_capability(capability, True);
 723 #endif /* HAVE_POSIX_CAPABILITIES */
 724 }
 725
 726 void drop_effective_capability(enum smbd_capability capability)
 727 {
 728 #if defined(HAVE_POSIX_CAPABILITIES)
 729         set_process_capability(capability, False);
 730 #endif /* HAVE_POSIX_CAPABILITIES */
 731 }
 732
 733 /**************************************************************************
 734  Wrapper for random().
 735 ****************************************************************************/
 736
 737 long sys_random(void)
 738 {
 739 #if defined(HAVE_RANDOM)
 740         return (long)random();
 741 #elif defined(HAVE_RAND)
 742         return (long)rand();
 743 #else
 744         DEBUG(0,("Error - no random function available !\n"));
 745         exit(1);
 746 #endif
 747 }
 748
 749 /**************************************************************************
 750  Wrapper for srandom().
 751 ****************************************************************************/
 752
 753 void sys_srandom(unsigned int seed)
 754 {
 755 #if defined(HAVE_SRANDOM)
 756         srandom(seed);
 757 #elif defined(HAVE_SRAND)
 758         srand(seed);
 759 #else
 760         DEBUG(0,("Error - no srandom function available !\n"));
 761         exit(1);
 762 #endif
 763 }
 764
 765 #ifndef NGROUPS_MAX
 766 #define NGROUPS_MAX 32 /* Guess... */
 767 #endif
 768
 769 /**************************************************************************
 770  Returns equivalent to NGROUPS_MAX - using sysconf if needed.
 771 ****************************************************************************/
 772
 773 int groups_max(void)
 774 {
 775 #if defined(SYSCONF_SC_NGROUPS_MAX)
 776         int ret = sysconf(_SC_NGROUPS_MAX);
 777         return (ret == -1) ? NGROUPS_MAX : ret;
 778 #else
 779         return NGROUPS_MAX;
 780 #endif
 781 }
 782
 783 /**************************************************************************
 784  Wrap setgroups and getgroups for systems that declare getgroups() as
 785  returning an array of gid_t, but actuall return an array of int.
 786 ****************************************************************************/
 787
 788 #if defined(HAVE_BROKEN_GETGROUPS)
 789
 790 #ifdef HAVE_BROKEN_GETGROUPS
 791 #define GID_T int
 792 #else
 793 #define GID_T gid_t
 794 #endif
 795
 796 static int sys_broken_getgroups(int setlen, gid_t *gidset)
 797 {
 798         GID_T *group_list;
 799         int i, ngroups;
 800
 801         if(setlen == 0) {
 802                 return getgroups(0, NULL);
 803         }
 804
 805         /*
 806          * Broken case. We need to allocate a
 807          * GID_T array of size setlen.
 808          */
 809
 810         if(setlen < 0) {
 811                 errno = EINVAL;
 812                 return -1;
 813         }
 814
 815         if((group_list = SMB_MALLOC_ARRAY(GID_T, setlen)) == NULL) {
 816                 DEBUG(0,("sys_getgroups: Malloc fail.\n"));
 817                 return -1;
 818         }
 819
 820         if((ngroups = getgroups(setlen, group_list)) < 0) {
 821                 int saved_errno = errno;
 822                 SAFE_FREE(group_list);
 823                 errno = saved_errno;
 824                 return -1;
 825         }
 826
 827         /*
 828          * We're safe here as if ngroups > setlen then
 829          * getgroups *must* return EINVAL.
 830          * pubs.opengroup.org/onlinepubs/009695399/functions/getgroups.html
 831          */
 832
 833         for(i = 0; i < ngroups; i++)
 834                 gidset[i] = (gid_t)group_list[i];
 835
 836         SAFE_FREE(group_list);
 837         return ngroups;
 838 }
 839
 840 static int sys_broken_setgroups(int setlen, gid_t *gidset)
 841 {
 842         GID_T *group_list;
 843         int i ;
 844
 845         if (setlen == 0)
 846                 return 0 ;
 847
 848         if (setlen < 0 || setlen > groups_max()) {
 849                 errno = EINVAL;
 850                 return -1;
 851         }
 852
 853         /*
 854          * Broken case. We need to allocate a
 855          * GID_T array of size setlen.
 856          */
 857
 858         if((group_list = SMB_MALLOC_ARRAY(GID_T, setlen)) == NULL) {
 859                 DEBUG(0,("sys_setgroups: Malloc fail.\n"));
 860                 return -1;
 861         }
 862
 863         for(i = 0; i < setlen; i++)
 864                 group_list[i] = (GID_T) gidset[i];
 865
 866         if(samba_setgroups(setlen, group_list) != 0) {
 867                 int saved_errno = errno;
 868                 SAFE_FREE(group_list);
 869                 errno = saved_errno;
 870                 return -1;
 871         }
 872
 873         SAFE_FREE(group_list);
 874         return 0 ;
 875 }
 876
 877 #endif /* HAVE_BROKEN_GETGROUPS */
 878
 879 /* This is a list of systems that require the first GID passed to setgroups(2)
 880  * to be the effective GID. If your system is one of these, add it here.
 881  */
 882 #if defined (FREEBSD) || defined (DARWINOS)
 883 #define USE_BSD_SETGROUPS
 884 #endif
 885
 886 #if defined(USE_BSD_SETGROUPS)
 887 /* Depending on the particular BSD implementation, the first GID that is
 888  * passed to setgroups(2) will either be ignored or will set the credential's
 889  * effective GID. In either case, the right thing to do is to guarantee that
 890  * gidset[0] is the effective GID.
 891  */
 892 static int sys_bsd_setgroups(gid_t primary_gid, int setlen, const gid_t *gidset)
 893 {
 894         gid_t *new_gidset = NULL;
 895         int max;
 896         int ret;
 897
 898         /* setgroups(2) will fail with EINVAL if we pass too many groups. */
 899         max = groups_max();
 900
 901         /* No group list, just make sure we are setting the efective GID. */
 902         if (setlen == 0) {
 903                 return samba_setgroups(1, &primary_gid);
 904         }
 905
 906         /* If the primary gid is not the first array element, grow the array
 907          * and insert it at the front.
 908          */
 909         if (gidset[0] != primary_gid) {
 910                 new_gidset = SMB_MALLOC_ARRAY(gid_t, setlen + 1);
 911                 if (new_gidset == NULL) {
 912                         return -1;
 913                 }
 914
 915                 memcpy(new_gidset + 1, gidset, (setlen * sizeof(gid_t)));
 916                 new_gidset[0] = primary_gid;
 917                 setlen++;
 918         }
 919
 920         if (setlen > max) {
 921                 DEBUG(3, ("forced to truncate group list from %d to %d\n",
 922                         setlen, max));
 923                 setlen = max;
 924         }
 925
 926 #if defined(HAVE_BROKEN_GETGROUPS)
 927         ret = sys_broken_setgroups(setlen, new_gidset ? new_gidset : gidset);
 928 #else
 929         ret = samba_setgroups(setlen, new_gidset ? new_gidset : gidset);
 930 #endif
 931
 932         if (new_gidset) {
 933                 int errsav = errno;
 934                 SAFE_FREE(new_gidset);
 935                 errno = errsav;
 936         }
 937
 938         return ret;
 939 }
 940
 941 #endif /* USE_BSD_SETGROUPS */
 942
 943 /**************************************************************************
 944  Wrapper for getgroups. Deals with broken (int) case.
 945 ****************************************************************************/
 946
 947 int sys_getgroups(int setlen, gid_t *gidset)
 948 {
 949 #if defined(HAVE_BROKEN_GETGROUPS)
 950         return sys_broken_getgroups(setlen, gidset);
 951 #else
 952         return getgroups(setlen, gidset);
 953 #endif
 954 }
 955
 956 /**************************************************************************
 957  Wrapper for setgroups. Deals with broken (int) case and BSD case.
 958 ****************************************************************************/
 959
 960 int sys_setgroups(gid_t UNUSED(primary_gid), int setlen, gid_t *gidset)
 961 {
 962 #if !defined(HAVE_SETGROUPS)
 963         errno = ENOSYS;
 964         return -1;
 965 #endif /* HAVE_SETGROUPS */
 966
 967 #if defined(USE_BSD_SETGROUPS)
 968         return sys_bsd_setgroups(primary_gid, setlen, gidset);
 969 #elif defined(HAVE_BROKEN_GETGROUPS)
 970         return sys_broken_setgroups(setlen, gidset);
 971 #else
 972         return samba_setgroups(setlen, gidset);
 973 #endif
 974 }
 975
 976 /****************************************************************************
 977  Return the major devicenumber for UNIX extensions.
 978 ****************************************************************************/
 979
 980 uint32_t unix_dev_major(SMB_DEV_T dev)
 981 {
 982 #if defined(HAVE_DEVICE_MAJOR_FN)
 983         return (uint32_t)major(dev);
 984 #else
 985         return (uint32_t)(dev >> 8);
 986 #endif
 987 }
 988
 989 /****************************************************************************
 990  Return the minor devicenumber for UNIX extensions.
 991 ****************************************************************************/
 992
 993 uint32_t unix_dev_minor(SMB_DEV_T dev)
 994 {
 995 #if defined(HAVE_DEVICE_MINOR_FN)
 996         return (uint32_t)minor(dev);
 997 #else
 998         return (uint32_t)(dev & 0xff);
 999 #endif
1000 }
1001
1002 /**************************************************************************
1003  Wrapper for realpath.
1004 ****************************************************************************/
1005
1006 char *sys_realpath(const char *path)
1007 {
1008         char *result;
1009
1010 #ifdef REALPATH_TAKES_NULL
1011         result = realpath(path, NULL);
1012 #else
1013         result = SMB_MALLOC_ARRAY(char, PATH_MAX + 1);
1014         if (result) {
1015                 char *resolved_path = realpath(path, result);
1016                 if (!resolved_path) {
1017                         SAFE_FREE(result);
1018                 } else {
1019                         /* SMB_ASSERT(result == resolved_path) ? */
1020                         result = resolved_path;
1021                 }
1022         }
1023 #endif
1024         return result;
1025 }
1026
1027 #if 0
1028 /*******************************************************************
1029  Return the number of CPUs.
1030 ********************************************************************/
1031
1032 int sys_get_number_of_cores(void)
1033 {
1034         int ret = -1;
1035
1036 #if defined(HAVE_SYSCONF)
1037 #if defined(_SC_NPROCESSORS_ONLN)
1038         ret = (int)sysconf(_SC_NPROCESSORS_ONLN);
1039 #endif
1040 #if defined(_SC_NPROCESSORS_CONF)
1041         if (ret < 1) {
1042                 ret = (int)sysconf(_SC_NPROCESSORS_CONF);
1043         }
1044 #endif
1045 #elif defined(HAVE_SYSCTL) && defined(CTL_HW)
1046         int name[2];
1047         unsigned int len = sizeof(ret);
1048
1049         name[0] = CTL_HW;
1050 #if defined(HW_AVAILCPU)
1051         name[1] = HW_AVAILCPU;
1052
1053         if (sysctl(name, 2, &ret, &len, NULL, 0) == -1) {
1054                 ret = -1;
1055         }
1056 #endif
1057 #if defined(HW_NCPU)
1058         if(ret < 1) {
1059                 name[0] = CTL_HW;
1060                 name[1] = HW_NCPU;
1061                 if (sysctl(nm, 2, &count, &len, NULL, 0) == -1) {
1062                         ret = -1;
1063                 }
1064         }
1065 #endif
1066 #endif
1067         if (ret < 1) {
1068                 ret = 1;
1069         }
1070         return ret;
1071 }
1072 #endif