/*

   Unix SMB/CIFS implementation.

   Samba system utilities

   Copyright (C) Andrew Tridgell 1992-1998

   Copyright (C) Jeremy Allison  1998-2005

   Copyright (C) Timur Bakeyev        2005

   Copyright (C) Bjoern Jacke    2006-2007

   This program is free software; you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3 of the License, or

   (at your option) any later version.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program.  If not, see <http://www.gnu.org/licenses/>.

*/

#include "includes.h"

#include "system/syslog.h"

#include "system/capability.h"

#include "system/passwd.h"

#include "system/filesys.h"

#include "lib/util/setid.h"

#include "lib/util/time.h"

#ifdef HAVE_SYS_SYSCTL_H

#include <sys/sysctl.h>

#endif

#ifdef HAVE_SYS_PRCTL_H

#include <sys/prctl.h>

#endif

/*

   The idea is that this file will eventually have wrappers around all

   important system calls in samba. The aims are:

   - to enable easier porting by putting OS dependent stuff in here

   - to allow for hooks into other "pseudo-filesystems"

   - to allow easier integration of things like the japanese extensions

   - to support the philosophy of Samba to expose the features of

     the OS within the SMB model. In general whatever file/printer/variable

     expansions/etc make sense to the OS should be acceptable to Samba.

*/

/*******************************************************************

A send wrapper that will deal with EINTR or EAGAIN or EWOULDBLOCK.

********************************************************************/

ssize_t sys_send(int s, const void *msg, size_t len, int flags)

{

  ssize_t ret;

  do {

    ret = send(s, msg, len, flags);

  } while (ret == -1 && (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK));

  return ret;

}

/*******************************************************************

A recvfrom wrapper that will deal with EINTR.

NB. As used with non-blocking sockets, return on EAGAIN/EWOULDBLOCK

********************************************************************/

ssize_t sys_recvfrom(int s, void *buf, size_t len, int flags, struct sockaddr *from, socklen_t *fromlen)

{

  ssize_t ret;

  do {

    ret = recvfrom(s, buf, len, flags, from, fromlen);

  } while (ret == -1 && (errno == EINTR));

  return ret;

}

/*******************************************************************

A fcntl wrapper that will deal with EINTR.

********************************************************************/

int sys_fcntl_ptr(int fd, int cmd, void *arg)

{

  int ret;

  do {

    ret = fcntl(fd, cmd, arg);

  } while (ret == -1 && errno == EINTR);

  return ret;

}

/*******************************************************************

A fcntl wrapper that will deal with EINTR.

********************************************************************/

int sys_fcntl_long(int fd, int cmd, long arg)

{

  int ret;

  do {

    ret = fcntl(fd, cmd, arg);

  } while (ret == -1 && errno == EINTR);

  return ret;

}

/*******************************************************************

A fcntl wrapper that will deal with EINTR.

********************************************************************/

int sys_fcntl_int(int fd, int cmd, int arg)

{

  int ret;

  do {

    ret = fcntl(fd, cmd, arg);

  } while (ret == -1 && errno == EINTR);

  return ret;

}

/****************************************************************************

 Return the best approximation to a 'create time' under UNIX from a stat

 structure.

****************************************************************************/

static struct timespec calc_create_time_stat(const struct stat *st)

{

  struct timespec ret, ret1;

  struct timespec c_time = get_ctimespec(st);

  struct timespec m_time = get_mtimespec(st);

  struct timespec a_time = get_atimespec(st);

  ret = timespec_compare(&c_time, &m_time) < 0 ? c_time : m_time;

  ret1 = timespec_compare(&ret, &a_time) < 0 ? ret : a_time;

  if(!null_timespec(ret1)) {

    return ret1;

  }

  /*

   * One of ctime, mtime or atime was zero (probably atime).

   * Just return MIN(ctime, mtime).

   */

  return ret;

}

/****************************************************************************

 Return the best approximation to a 'create time' under UNIX from a stat_ex

 structure.

****************************************************************************/

static struct timespec calc_create_time_stat_ex(const struct stat_ex *st)

{

  struct timespec ret, ret1;

  struct timespec c_time = st->st_ex_ctime;

  struct timespec m_time = st->st_ex_mtime;

  struct timespec a_time = st->st_ex_atime;

  ret = timespec_compare(&c_time, &m_time) < 0 ? c_time : m_time;

  ret1 = timespec_compare(&ret, &a_time) < 0 ? ret : a_time;

  if(!null_timespec(ret1)) {

    return ret1;

  }

  /*

   * One of ctime, mtime or atime was zero (probably atime).

   * Just return MIN(ctime, mtime).

   */

  return ret;

}

/****************************************************************************

 Return the 'create time' from a stat struct if it exists (birthtime) or else

 use the best approximation.

****************************************************************************/

static void make_create_timespec(const struct stat *pst, struct stat_ex *dst,

         bool fake_dir_create_times)

{

  if (S_ISDIR(pst->st_mode) && fake_dir_create_times) {

    dst->st_ex_btime.tv_sec = 315493200L;          /* 1/1/1980 */

    dst->st_ex_btime.tv_nsec = 0;

    return;

  }

  dst->st_ex_iflags &= ~ST_EX_IFLAG_CALCULATED_BTIME;

#if defined(HAVE_STRUCT_STAT_ST_BIRTHTIMESPEC_TV_NSEC)

  dst->st_ex_btime = pst->st_birthtimespec;

#elif defined(HAVE_STRUCT_STAT_ST_BIRTHTIMENSEC)

  dst->st_ex_btime.tv_sec = pst->st_birthtime;

  dst->st_ex_btime.tv_nsec = pst->st_birthtimenspec;

#elif defined(HAVE_STRUCT_STAT_ST_BIRTHTIME)

  dst->st_ex_btime.tv_sec = pst->st_birthtime;

  dst->st_ex_btime.tv_nsec = 0;

#else

  dst->st_ex_btime = calc_create_time_stat(pst);

  dst->st_ex_iflags |= ST_EX_IFLAG_CALCULATED_BTIME;

#endif

  /* Deal with systems that don't initialize birthtime correctly.

   * Pointed out by SATOH Fumiyasu <fumiyas@osstech.jp>.

   */

  if (null_timespec(dst->st_ex_btime)) {

    dst->st_ex_btime = calc_create_time_stat(pst);

    dst->st_ex_iflags |= ST_EX_IFLAG_CALCULATED_BTIME;

  }

}

/****************************************************************************

 If we update a timestamp in a stat_ex struct we may have to recalculate

 the birthtime. For now only implement this for write time, but we may

 also need to do it for atime and ctime. JRA.

****************************************************************************/

void update_stat_ex_mtime(struct stat_ex *dst,

        struct timespec write_ts)

{

  dst->st_ex_mtime = write_ts;

  /* We may have to recalculate btime. */

  if (dst->st_ex_iflags & ST_EX_IFLAG_CALCULATED_BTIME) {

    dst->st_ex_btime = calc_create_time_stat_ex(dst);

  }

}

void update_stat_ex_create_time(struct stat_ex *dst,

                                struct timespec create_time)

{

  dst->st_ex_btime = create_time;

  dst->st_ex_iflags &= ~ST_EX_IFLAG_CALCULATED_BTIME;

}

void update_stat_ex_from_saved_stat(struct stat_ex *dst,

            const struct stat_ex *src)

{

  if (!VALID_STAT(*src)) {

    return;

  }

  if (!(src->st_ex_iflags & ST_EX_IFLAG_CALCULATED_BTIME)) {

    update_stat_ex_create_time(dst, src->st_ex_btime);

  }

}

void copy_stat_ex_timestamps(struct stat_ex *st,

           const struct smb_file_time *ft)

{

  if (!is_omit_timespec(&ft->atime)) {

    st->st_ex_atime = ft->atime;

  }

  if (!is_omit_timespec(&ft->create_time)) {

    st->st_ex_btime = ft->create_time;

  }

  if (!is_omit_timespec(&ft->ctime)) {

    st->st_ex_ctime = ft->ctime;

  }

  if (!is_omit_timespec(&ft->mtime)) {

    st->st_ex_mtime = ft->mtime;

  }

}

void init_stat_ex_from_stat (struct stat_ex *dst,

          const struct stat *src,

          bool fake_dir_create_times)

{

  dst->st_ex_dev = src->st_dev;

  dst->st_ex_ino = src->st_ino;

  dst->st_ex_mode = src->st_mode;

  dst->st_ex_nlink = src->st_nlink;

  dst->st_ex_uid = src->st_uid;

  dst->st_ex_gid = src->st_gid;

  dst->st_ex_rdev = src->st_rdev;

  dst->st_ex_size = src->st_size;

  dst->st_ex_atime = get_atimespec(src);

  dst->st_ex_mtime = get_mtimespec(src);

  dst->st_ex_ctime = get_ctimespec(src);

  dst->st_ex_iflags = 0;

  make_create_timespec(src, dst, fake_dir_create_times);

#ifdef HAVE_STAT_ST_BLKSIZE

  dst->st_ex_blksize = src->st_blksize;

#else

  dst->st_ex_blksize = STAT_ST_BLOCKSIZE;

#endif

#ifdef HAVE_STAT_ST_BLOCKS

  dst->st_ex_blocks = src->st_blocks;

#else

  dst->st_ex_blocks = src->st_size / dst->st_ex_blksize + 1;

#endif

#ifdef HAVE_STAT_ST_FLAGS

  dst->st_ex_flags = src->st_flags;

#else

  dst->st_ex_flags = 0;

#endif

}

/*******************************************************************

A stat() wrapper.

********************************************************************/

int sys_stat(const char *fname, SMB_STRUCT_STAT *sbuf,

       bool fake_dir_create_times)

{

  int ret;

  struct stat statbuf;

  ret = stat(fname, &statbuf);

  if (ret == 0) {

    /* we always want directories to appear zero size */

    if (S_ISDIR(statbuf.st_mode)) {

      statbuf.st_size = 0;

    }

    init_stat_ex_from_stat(sbuf, &statbuf, fake_dir_create_times);

  }

  return ret;

}

/*******************************************************************

 An fstat() wrapper.

********************************************************************/

int sys_fstat(int fd, SMB_STRUCT_STAT *sbuf, bool fake_dir_create_times)

{

  int ret;

  struct stat statbuf;

  ret = fstat(fd, &statbuf);

  if (ret == 0) {

    /* we always want directories to appear zero size */

    if (S_ISDIR(statbuf.st_mode)) {

      statbuf.st_size = 0;

    }

    init_stat_ex_from_stat(sbuf, &statbuf, fake_dir_create_times);

  }

  return ret;

}

/*******************************************************************

 An lstat() wrapper.

********************************************************************/

int sys_lstat(const char *fname,SMB_STRUCT_STAT *sbuf,

        bool fake_dir_create_times)

{

  int ret;

  struct stat statbuf;

  ret = lstat(fname, &statbuf);

  if (ret == 0) {

    /* we always want directories to appear zero size */

    if (S_ISDIR(statbuf.st_mode)) {

      statbuf.st_size = 0;

    }

    init_stat_ex_from_stat(sbuf, &statbuf, fake_dir_create_times);

  }

  return ret;

}

/*******************************************************************

 An fstatat() wrapper.

********************************************************************/

int sys_fstatat(int fd,

    const char *pathname,

    SMB_STRUCT_STAT *sbuf,

    int flags,

    bool fake_dir_create_times)

{

  int ret;

  struct stat statbuf;

  ret = fstatat(fd, pathname, &statbuf, flags);

  if (ret != 0) {

    return -1;

  }

  /* we always want directories to appear zero size */

  if (S_ISDIR(statbuf.st_mode)) {

    statbuf.st_size = 0;

  }

  init_stat_ex_from_stat(sbuf, &statbuf, fake_dir_create_times);

  return 0;

}

/*******************************************************************

 An posix_fallocate() wrapper.

********************************************************************/

int sys_posix_fallocate(int fd, off_t offset, off_t len)

{

#if defined(HAVE_POSIX_FALLOCATE)

  return posix_fallocate(fd, offset, len);

#elif defined(F_RESVSP64)

  /* this handles XFS on IRIX */

  struct flock64 fl;

  off_t new_len = offset + len;

  int ret;

  struct stat64 sbuf;

  /* unlikely to get a too large file on a 64bit system but ... */

  if (new_len < 0)

    return EFBIG;

  fl.l_whence = SEEK_SET;

  fl.l_start = offset;

  fl.l_len = len;

  ret=fcntl(fd, F_RESVSP64, &fl);

  if (ret != 0)

    return errno;

  /* Make sure the file gets enlarged after we allocated space: */

  fstat64(fd, &sbuf);

  if (new_len > sbuf.st_size)

    ftruncate64(fd, new_len);

  return 0;

#else

  return ENOSYS;

#endif

}

/*******************************************************************

 An fallocate() function that matches the semantics of the Linux one.

********************************************************************/

#ifdef HAVE_LINUX_FALLOC_H

#include <linux/falloc.h>

#endif

int sys_fallocate(int fd, uint32_t mode, off_t offset, off_t len)

{

#if defined(HAVE_LINUX_FALLOCATE)

  int lmode = 0;

  if (mode & VFS_FALLOCATE_FL_KEEP_SIZE) {

    lmode |= FALLOC_FL_KEEP_SIZE;

    mode &= ~VFS_FALLOCATE_FL_KEEP_SIZE;

  }

#if defined(HAVE_FALLOC_FL_PUNCH_HOLE)

  if (mode & VFS_FALLOCATE_FL_PUNCH_HOLE) {

    lmode |= FALLOC_FL_PUNCH_HOLE;

    mode &= ~VFS_FALLOCATE_FL_PUNCH_HOLE;

  }

#endif  /* HAVE_FALLOC_FL_PUNCH_HOLE */

  if (mode != 0) {

    DEBUG(2, ("unmapped fallocate flags: %lx\n",

          (unsigned long)mode));

    errno = EINVAL;

    return -1;

  }

  return fallocate(fd, lmode, offset, len);

#else /* HAVE_LINUX_FALLOCATE */

  /* TODO - plumb in fallocate from other filesysetms like VXFS etc. JRA. */

  errno = ENOSYS;

  return -1;

#endif  /* HAVE_LINUX_FALLOCATE */

}

/*******************************************************************

 An fdopendir wrapper.

********************************************************************/

DIR *sys_fdopendir(int fd)

{

#if defined(HAVE_FDOPENDIR)

  return fdopendir(fd);

#else

  errno = ENOSYS;

  return NULL;

#endif

}

/*******************************************************************

 An mknod() wrapper.

********************************************************************/

int sys_mknod(const char *path, mode_t mode, SMB_DEV_T dev)

{

#if defined(HAVE_MKNOD)

  return mknod(path, mode, dev);

#else

  /* No mknod system call. */

  errno = ENOSYS;

  return -1;

#endif

}

/*******************************************************************

 A mknodat() wrapper.

********************************************************************/

int sys_mknodat(int dirfd, const char *path, mode_t mode, SMB_DEV_T dev)

{

#if defined(HAVE_MKNODAT)

  return mknodat(dirfd, path, mode, dev);

#else

  /* No mknod system call. */

  errno = ENOSYS;

  return -1;

#endif

}

/*******************************************************************

 System wrapper for getwd. Always returns MALLOC'ed memory, or NULL

 on error (malloc fail usually).

********************************************************************/

char *sys_getwd(void)

{

#ifdef GETCWD_TAKES_NULL

  return getcwd(NULL, 0);

#elif defined(HAVE_GETCWD)

  char *wd = NULL, *s = NULL;

  size_t allocated = PATH_MAX;

  while (1) {

    s = SMB_REALLOC_ARRAY(s, char, allocated);

    if (s == NULL) {

      return NULL;

    }

    wd = getcwd(s, allocated);

    if (wd) {

      break;

    }

    if (errno != ERANGE) {

      int saved_errno = errno;

      SAFE_FREE(s);

      errno = saved_errno;

      break;

    }

    allocated *= 2;

    if (allocated < PATH_MAX) {

      SAFE_FREE(s);

      break;

    }

  }

  return wd;

#else

  char *wd = NULL;

  char *s = SMB_MALLOC_ARRAY(char, PATH_MAX);

  if (s == NULL) {

    return NULL;

  }

  wd = getwd(s);

  if (wd == NULL) {

    int saved_errno = errno;

    SAFE_FREE(s);

    errno = saved_errno;

  }

  return wd;

#endif

}

#if defined(HAVE_POSIX_CAPABILITIES)

/**************************************************************************

 Try and abstract process capabilities (for systems that have them).

****************************************************************************/

/* Set the POSIX capabilities needed for the given purpose into the effective

 * capability set of the current process. Make sure they are always removed

 * from the inheritable set, because there is no circumstance in which our

 * children should inherit our elevated privileges.

 */

static bool set_process_capability(enum smbd_capability capability,

           bool enable)

{

  /* "5" is the number of "num_cap_vals++" below */

  cap_value_t cap_vals[5] = {0};

  size_t num_cap_vals = 0;

  cap_t cap;

#if defined(HAVE_PRCTL) && defined(PR_GET_KEEPCAPS) && defined(PR_SET_KEEPCAPS)

  /* On Linux, make sure that any capabilities we grab are sticky

   * across UID changes. We expect that this would allow us to keep both

   * the effective and permitted capability sets, but as of circa 2.6.16,

   * only the permitted set is kept. It is a bug (which we work around)

   * that the effective set is lost, but we still require the effective

   * set to be kept.

   */

  if (!prctl(PR_GET_KEEPCAPS)) {

    prctl(PR_SET_KEEPCAPS, 1);

  }

#endif

  cap = cap_get_proc();

  if (cap == NULL) {

    DEBUG(0,("set_process_capability: cap_get_proc failed: %s\n",

      strerror(errno)));

    return False;

  }

  switch (capability) {

    /*

     * WARNING: If you add any #ifdef for a fresh

     * capability, bump up the array size in the

     * declaration of cap_vals[] above just to be

     * trivially safe to never overwrite cap_vals[].

     */

    case KERNEL_OPLOCK_CAPABILITY:

#ifdef CAP_NETWORK_MGT

      /* IRIX has CAP_NETWORK_MGT for oplocks. */

      cap_vals[num_cap_vals++] = CAP_NETWORK_MGT;

#endif

      break;

    case DMAPI_ACCESS_CAPABILITY:

#ifdef CAP_DEVICE_MGT

      /* IRIX has CAP_DEVICE_MGT for DMAPI access. */

      cap_vals[num_cap_vals++] = CAP_DEVICE_MGT;

#elif CAP_MKNOD

      /* Linux has CAP_MKNOD for DMAPI access. */

      cap_vals[num_cap_vals++] = CAP_MKNOD;

#endif

      break;

    case LEASE_CAPABILITY:

#ifdef CAP_LEASE

      cap_vals[num_cap_vals++] = CAP_LEASE;

#endif

      break;

    case DAC_OVERRIDE_CAPABILITY:

#ifdef CAP_DAC_OVERRIDE

      cap_vals[num_cap_vals++] = CAP_DAC_OVERRIDE;

#endif

  }

  if (num_cap_vals == 0) {

    cap_free(cap);

    return True;

  }

  cap_set_flag(cap, CAP_EFFECTIVE, num_cap_vals, cap_vals,

    enable ? CAP_SET : CAP_CLEAR);

  /* We never want to pass capabilities down to our children, so make

   * sure they are not inherited.

   */

  cap_set_flag(cap, CAP_INHERITABLE, num_cap_vals, cap_vals, CAP_CLEAR);

  if (cap_set_proc(cap) == -1) {

    DBG_ERR("%s capability %d: cap_set_proc failed: %s\n",

      enable ? "adding" : "dropping",

      capability, strerror(errno));

    cap_free(cap);

    return False;

  }

  DBG_INFO("%s capability %d\n",

     enable ? "added" : "dropped", capability);

  cap_free(cap);

  return True;

}

#endif /* HAVE_POSIX_CAPABILITIES */

/****************************************************************************

 Gain the oplock capability from the kernel if possible.

****************************************************************************/

#if defined(HAVE_POSIX_CAPABILITIES) && defined(CAP_DAC_OVERRIDE)

static bool have_cap_dac_override = true;

#else

static bool have_cap_dac_override = false;

#endif

void set_effective_capability(enum smbd_capability capability)

{

  bool ret = false;

  if (capability != DAC_OVERRIDE_CAPABILITY || have_cap_dac_override) {

#if defined(HAVE_POSIX_CAPABILITIES)

    ret = set_process_capability(capability, True);

#endif /* HAVE_POSIX_CAPABILITIES */

  }

  /*

   * Fallback to become_root() if CAP_DAC_OVERRIDE is not

   * available.

   */

  if (capability == DAC_OVERRIDE_CAPABILITY) {

    if (!ret) {

      have_cap_dac_override = false;

    }

    if (!have_cap_dac_override) {

      become_root();

    }

  }

}

void drop_effective_capability(enum smbd_capability capability)

{

  if (capability != DAC_OVERRIDE_CAPABILITY || have_cap_dac_override) {

#if defined(HAVE_POSIX_CAPABILITIES)

    set_process_capability(capability, False);

#endif /* HAVE_POSIX_CAPABILITIES */

  } else {

    unbecome_root();

  }

}

/**************************************************************************

 Wrapper for random().

****************************************************************************/

long sys_random(void)

{

#if defined(HAVE_RANDOM)

  return (long)random();

#elif defined(HAVE_RAND)

  return (long)rand();

#else

  DEBUG(0,("Error - no random function available !\n"));

  exit(1);

#endif

}

/**************************************************************************

 Wrapper for srandom().

****************************************************************************/

void sys_srandom(unsigned int seed)

{

#if defined(HAVE_SRANDOM)

  srandom(seed);

#elif defined(HAVE_SRAND)

  srand(seed);

#else

  DEBUG(0,("Error - no srandom function available !\n"));

  exit(1);

#endif

}

#ifndef NGROUPS_MAX

#define NGROUPS_MAX 32 /* Guess... */

#endif

/**************************************************************************

 Returns equivalent to NGROUPS_MAX - using sysconf if needed.

****************************************************************************/

int setgroups_max(void)

{

#if defined(SYSCONF_SC_NGROUPS_MAX)

  int ret = sysconf(_SC_NGROUPS_MAX);

  return (ret == -1) ? NGROUPS_MAX : ret;

#else

  return NGROUPS_MAX;

#endif

}

int getgroups_max(void)

{

#if defined(DARWINOS)

  /*

   * On MacOS sysconf(_SC_NGROUPS_MAX) returns 16 due to MacOS's group

   * nesting. However, The initgroups() manpage states the following:

   * "Note that OS X supports group membership in an unlimited number

   * of groups. The OS X kernel uses the group list stored in the process

   * credentials only as an initial cache.  Additional group memberships

   * are determined by communication between the operating system and the

   * opendirectoryd daemon."

   */

  return INT_MAX;

#else

  return setgroups_max();

#endif

}

/**************************************************************************

 Wrap setgroups and getgroups for systems that declare getgroups() as

 returning an array of gid_t, but actually return an array of int.

****************************************************************************/

#if defined(HAVE_BROKEN_GETGROUPS)

#ifdef HAVE_BROKEN_GETGROUPS

#define GID_T int

#else

#define GID_T gid_t

#endif

static int sys_broken_getgroups(int setlen, gid_t *gidset)

{

  GID_T *group_list;

  int i, ngroups;

  if(setlen == 0) {

    return getgroups(0, NULL);

  }

  /*

   * Broken case. We need to allocate a

   * GID_T array of size setlen.

   */

  if(setlen < 0) {

    errno = EINVAL;

    return -1;

  }

  if((group_list = SMB_MALLOC_ARRAY(GID_T, setlen)) == NULL) {

    DEBUG(0,("sys_getgroups: Malloc fail.\n"));

    return -1;

  }

  if((ngroups = getgroups(setlen, group_list)) < 0) {

    int saved_errno = errno;

    SAFE_FREE(group_list);

    errno = saved_errno;

    return -1;

  }

  /*

   * We're safe here as if ngroups > setlen then

   * getgroups *must* return EINVAL.

   * pubs.opengroup.org/onlinepubs/009695399/functions/getgroups.html

   */

  for(i = 0; i < ngroups; i++)

    gidset[i] = (gid_t)group_list[i];

  SAFE_FREE(group_list);

  return ngroups;

}

static int sys_broken_setgroups(int setlen, gid_t *gidset)

{

  GID_T *group_list;

  int i ;

  if (setlen == 0)

    return 0 ;

  if (setlen < 0 || setlen > setgroups_max()) {

    errno = EINVAL;

    return -1;

  }

  /*

   * Broken case. We need to allocate a

   * GID_T array of size setlen.

   */

  if((group_list = SMB_MALLOC_ARRAY(GID_T, setlen)) == NULL) {

    DEBUG(0,("sys_setgroups: Malloc fail.\n"));

    return -1;

  }

  for(i = 0; i < setlen; i++)

    group_list[i] = (GID_T) gidset[i];

  if(samba_setgroups(setlen, group_list) != 0) {

    int saved_errno = errno;

    SAFE_FREE(group_list);

    errno = saved_errno;

    return -1;

  }

  SAFE_FREE(group_list);

  return 0 ;

}

#endif /* HAVE_BROKEN_GETGROUPS */

/* This is a list of systems that require the first GID passed to setgroups(2)

 * to be the effective GID. If your system is one of these, add it here.

 */

#if defined (FREEBSD) || defined (DARWINOS)

#define USE_BSD_SETGROUPS

#endif

#if defined(USE_BSD_SETGROUPS)

/* Depending on the particular BSD implementation, the first GID that is

 * passed to setgroups(2) will either be ignored or will set the credential's

 * effective GID. In either case, the right thing to do is to guarantee that

 * gidset[0] is the effective GID.

 */

static int sys_bsd_setgroups(gid_t primary_gid, int setlen, const gid_t *gidset)

{

  gid_t *new_gidset = NULL;

  int max;

  int ret;

  /* setgroups(2) will fail with EINVAL if we pass too many groups. */

  max = setgroups_max();

  /* No group list, just make sure we are setting the effective GID. */

  if (setlen == 0) {

    return samba_setgroups(1, &primary_gid);

  }

  /* If the primary gid is not the first array element, grow the array

   * and insert it at the front.

   */

  if (gidset[0] != primary_gid) {

          new_gidset = SMB_MALLOC_ARRAY(gid_t, setlen + 1);

          if (new_gidset == NULL) {

      return -1;

          }

    memcpy(new_gidset + 1, gidset, (setlen * sizeof(gid_t)));

    new_gidset[0] = primary_gid;

    setlen++;

  }

  if (setlen > max) {

    DEBUG(3, ("forced to truncate group list from %d to %d\n",

      setlen, max));

    setlen = max;

  }

#if defined(HAVE_BROKEN_GETGROUPS)

  ret = sys_broken_setgroups(setlen, new_gidset ? new_gidset : gidset);

#else

  ret = samba_setgroups(setlen, new_gidset ? new_gidset : gidset);

#endif

  if (new_gidset) {

    int errsav = errno;

    SAFE_FREE(new_gidset);

    errno = errsav;

  }

  return ret;

}

#endif /* USE_BSD_SETGROUPS */

/**************************************************************************

 Wrapper for getgroups. Deals with broken (int) case.

****************************************************************************/

int sys_getgroups(int setlen, gid_t *gidset)

{

#if defined(HAVE_BROKEN_GETGROUPS)

  return sys_broken_getgroups(setlen, gidset);

#else

  return getgroups(setlen, gidset);

#endif

}

/**************************************************************************

 Wrapper for setgroups. Deals with broken (int) case and BSD case.

****************************************************************************/

int sys_setgroups(gid_t UNUSED(primary_gid), int setlen, gid_t *gidset)

{

#if !defined(HAVE_SETGROUPS)

  errno = ENOSYS;

  return -1;

#endif /* HAVE_SETGROUPS */

#if defined(USE_BSD_SETGROUPS)

  return sys_bsd_setgroups(primary_gid, setlen, gidset);

#elif defined(HAVE_BROKEN_GETGROUPS)

  return sys_broken_setgroups(setlen, gidset);

#else

  return samba_setgroups(setlen, gidset);

#endif

}

/****************************************************************************

 Return the major devicenumber for UNIX extensions.

****************************************************************************/

uint32_t unix_dev_major(SMB_DEV_T dev)

{

#if defined(HAVE_DEVICE_MAJOR_FN)

        return (uint32_t)major(dev);

#else

        return (uint32_t)(dev >> 8);

#endif

}

/****************************************************************************

 Return the minor devicenumber for UNIX extensions.

****************************************************************************/

uint32_t unix_dev_minor(SMB_DEV_T dev)

{

#if defined(HAVE_DEVICE_MINOR_FN)

        return (uint32_t)minor(dev);

#else

        return (uint32_t)(dev & 0xff);

#endif

}

/**************************************************************************

 Wrapper for realpath.

****************************************************************************/

char *sys_realpath(const char *path)

{

  char *result;

#ifdef REALPATH_TAKES_NULL

  result = realpath(path, NULL);

#else

  result = SMB_MALLOC_ARRAY(char, PATH_MAX + 1);

  if (result) {

    char *resolved_path = realpath(path, result);

    if (!resolved_path) {

      SAFE_FREE(result);