idpriv-droptemp.c

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Hash : b1fcec6d
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Date : 2025-09-10T23:22:53

Remove support for IRIX.

* all-modules: Update comments.
* build-aux/install-reloc: Likewise.
* build-aux/reloc-ldflags: Likewise.
* gnulib-tool: Likewise.
* gnulib-tool.py: Likewise.
* gnulib-tool.sh: Likewise.
* lib/aligned-malloc.h: Likewise.
* lib/boot-time.c: Likewise.
* lib/c32is-impl.h: Likewise.
* lib/c32srtombs-state.c: Likewise.
* lib/c32to-impl.h: Likewise.
* lib/c32width.c: Likewise.
* lib/errno.in.h: Likewise.
* lib/euidaccess.c: Likewise.
* lib/fbufmode.c: Likewise.
* lib/fenv-except-state-get.c: Likewise.
* lib/fenv-except-state-set.c: Likewise.
* lib/fenv-except-tracking-clear.c: Likewise.
* lib/fenv-except-tracking-set.c: Likewise.
* lib/fenv-except-tracking-test.c: Likewise.
* lib/fenv-except-trapping.c: Likewise.
* lib/fenv-round.c: Likewise.
* lib/fflush.c: Likewise.
* lib/fileblocks.c: Likewise.
* lib/forkpty.c: Likewise.
* lib/fpending.c: Likewise.
* lib/fpurge.c: Likewise.
* lib/freadable.c: Likewise.
* lib/freadahead.c: Likewise.
* lib/freading.c: Likewise.
* lib/freadptr.c: Likewise.
* lib/freadseek.c: Likewise.
* lib/fseeko.c: Likewise.
* lib/fseterr.c: Likewise.
* lib/fsusage.c: Likewise.
* lib/fwritable.c: Likewise.
* lib/fwriting.c: Likewise.
* lib/getdomainname.c: Likewise.
* lib/idpriv-drop.c: Likewise.
* lib/idpriv-droptemp.c: Likewise.
* lib/limits.in.h: Likewise.
* lib/mbrtoc16.c: Likewise.
* lib/mbrtoc32.c: Likewise.
* lib/mbsrtoc32s-state.c: Likewise.
* lib/mbsrtowcs-state.c: Likewise.
* lib/mbtowc-lock.h: Likewise.
* lib/minmax.h: Likewise.
* lib/netdb.in.h: Likewise.
* lib/pipe-filter-ii.c: Likewise.
* lib/posix_openpt.c: Likewise.
* lib/ptsname_r.c: Likewise.
* lib/readutmp.c: Likewise.
* lib/readutmp.h: Likewise.
* lib/resource-ext.h: Likewise.
* lib/safe-read.h: Likewise.
* lib/safe-write.h: Likewise.
* lib/save-cwd.c: Likewise.
* lib/stdbool.in.h: Likewise.
* lib/striconv.c: Likewise.
* lib/striconveh.c: Likewise.
* lib/termcap.h: Likewise.
* lib/terminfo.h: Likewise.
* lib/unistd.in.h: Likewise.
* lib/vasnprintf.c: Likewise.
* lib/wcrtomb.c: Likewise.
* lib/wcsrtombs-state.c: Likewise.
* m4/fenv-environment.m4: Likewise.
* m4/fenv-exceptions-state.m4: Likewise.
* m4/fenv-exceptions-tracking.m4: Likewise.
* m4/fenv-rounding.m4: Likewise.
* m4/fmod.m4: Likewise.
* m4/getdomainname.m4: Likewise.
* m4/getloadavg.m4: Likewise.
* m4/getopt.m4: Likewise.
* m4/hypot.m4: Likewise.
* m4/hypotf.m4: Likewise.
* m4/hypotl.m4: Likewise.
* m4/iconv.m4: Likewise.
* m4/intl-thread-locale.m4: Likewise.
* m4/largefile.m4: Likewise.
* m4/libdl.m4: Likewise.
* m4/locale-ja.m4: Likewise.
* m4/locale_h.m4: Likewise.
* m4/log.m4: Likewise.
* m4/log10.m4: Likewise.
* m4/log10f.m4: Likewise.
* m4/logf.m4: Likewise.
* m4/modf.m4: Likewise.
* m4/modff.m4: Likewise.
* m4/modfl.m4: Likewise.
* m4/pthread-rwlock.m4: Likewise.
* m4/semaphore.m4: Likewise.
* m4/socklen.m4: Likewise.
* m4/stdint.m4: Likewise.
* m4/strtod.m4: Likewise.
* m4/strtof.m4: Likewise.
* m4/strtold.m4: Likewise.
* modules/sigsegv: Likewise.
* posix-modules: Likewise.
* pygnulib/GLImport.py: Likewise.
* tests/init.sh: Likewise.
* tests/test-echo.sh: Likewise.
* tests/test-isatty.c: Likewise.
* tests/test-math-h.c: Likewise.
* tests/test-nonblocking-pipe.h: Likewise.
* tests/test-nonblocking-socket.h: Likewise.
* tests/test-strtod.h: Likewise.
* tests/test-strtof.h: Likewise.
* tests/test-strtold.h: Likewise.
* tests/test-vasnprintf.c: Likewise.
* tests/test-vasnwprintf.c: Likewise.

Download

lib/idpriv-droptemp.c

/* Dropping uid/gid privileges of the current process temporarily.
   Copyright (C) 2009-2025 Free Software Foundation, Inc.

   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 <https://www.gnu.org/licenses/>.  */

#include <config.h>

#include "idpriv.h"

#include <errno.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>

/* The privileged uid and gid that the process had earlier.  */
#if HAVE_GETUID
static uid_t saved_uid = -1;
#endif
#if HAVE_GETGID
static gid_t saved_gid = -1;
#endif

int
idpriv_temp_drop (void)
{
#if HAVE_GETEUID && HAVE_GETEGID && (HAVE_SETRESUID || HAVE_SETREUID) && (HAVE_SETRESGID || HAVE_SETREGID)
  uid_t uid = getuid ();
  gid_t gid = getgid ();

  /* Find out about the privileged uid and gid at the first call.  */
  if (saved_uid == -1)
    saved_uid = geteuid ();
  if (saved_gid == -1)
    saved_gid = getegid ();

  /* Drop the gid privilege first, because in some cases the gid privilege
     cannot be dropped after the uid privilege has been dropped.  */

  /* This is for executables that have the setgid bit set.  */
# if HAVE_SETRESGID /* glibc, FreeBSD, OpenBSD, HP-UX */
  if (setresgid (-1, gid, saved_gid) < 0)
    return -1;
# else /* Mac OS X, NetBSD, AIX, Solaris >= 2.5, Cygwin */
  if (setregid (-1, gid) < 0)
    return -1;
# endif

  /* This is for executables that have the setuid bit set.  */
# if HAVE_SETRESUID /* glibc, FreeBSD, OpenBSD, HP-UX */
  /* See
       Hao Chen, David Wagner, Drew Dean: Setuid Demystified
       <https://www.usenix.org/legacy/publications/library/proceedings/sec02/full_papers/chen/chen.pdf>
     figure 14.  */
  if (setresuid (-1, uid, saved_uid) < 0)
    return -1;
# else /* Mac OS X, NetBSD, AIX, Solaris >= 2.5, Cygwin */
  if (setreuid (-1, uid) < 0)
    return -1;
# endif

  /* Verify that the privileges have really been dropped.
     This verification is here for security reasons.  Doesn't matter if it
     takes a couple of system calls.
     When the verification fails, it indicates that we need to use different
     API in the code above. Therefore 'abort ()', not 'return -1'.  */
# if HAVE_GETRESUID /* glibc, FreeBSD, OpenBSD, HP-UX */
  {
    uid_t real;
    uid_t effective;
    uid_t saved;
    if (getresuid (&real, &effective, &saved) < 0
        || real != uid
        || effective != uid
        || saved != saved_uid)
      abort ();
  }
# else
#  if HAVE_GETEUID
  if (geteuid () != uid)
    abort ();
#  endif
  if (getuid () != uid)
    abort ();
# endif
# if HAVE_GETRESGID /* glibc, FreeBSD, OpenBSD, HP-UX */
  {
    uid_t real;
    uid_t effective;
    uid_t saved;
    if (getresgid (&real, &effective, &saved) < 0
        || real != gid
        || effective != gid
        || saved != saved_gid)
      abort ();
  }
# else
#  if HAVE_GETEGID
  if (getegid () != gid)
    abort ();
#  endif
  if (getgid () != gid)
    abort ();
# endif

  return 0;
#else
  errno = ENOSYS;
  return -1;
#endif
}

int
idpriv_temp_restore (void)
{
#if HAVE_GETEUID && HAVE_GETEGID && (HAVE_SETRESUID || HAVE_SETREUID) && (HAVE_SETRESGID || HAVE_SETREGID)
  uid_t uid = getuid ();
  gid_t gid = getgid ();

  if (saved_uid == -1 || saved_gid == -1)
    /* Caller error: idpriv_temp_drop was never invoked.  */
    abort ();

  /* Acquire the gid privilege last, because in some cases the gid privilege
     cannot be acquired before the uid privilege has been acquired.  */

  /* This is for executables that have the setuid bit set.  */
# if HAVE_SETRESUID /* glibc, FreeBSD, OpenBSD, HP-UX */
  /* See
       Hao Chen, David Wagner, Drew Dean: Setuid Demystified
       <https://www.usenix.org/legacy/publications/library/proceedings/sec02/full_papers/chen/chen.pdf>
     figure 14.  */
  if (setresuid (-1, saved_uid, -1) < 0)
    return -1;
# else /* Mac OS X, NetBSD, AIX, Solaris >= 2.5, Cygwin */
  if (setreuid (-1, saved_uid) < 0)
    return -1;
# endif

  /* This is for executables that have the setgid bit set.  */
# if HAVE_SETRESGID /* glibc, FreeBSD, OpenBSD, HP-UX */
  if (setresgid (-1, saved_gid, -1) < 0)
    return -1;
# else /* Mac OS X, NetBSD, AIX, Solaris >= 2.5, Cygwin */
  if (setregid (-1, saved_gid) < 0)
    return -1;
# endif

  /* Verify that the privileges have really been acquired.
     This verification is here for security reasons.  Doesn't matter if it
     takes a couple of system calls.
     When the verification fails, it indicates that we need to use different
     API in the code above. Therefore 'abort ()', not 'return -1'.  */
# if HAVE_GETRESUID /* glibc, FreeBSD, OpenBSD, HP-UX */
  {
    uid_t real;
    uid_t effective;
    uid_t saved;
    if (getresuid (&real, &effective, &saved) < 0
        || real != uid
        || effective != saved_uid
        || saved != saved_uid)
      abort ();
  }
# else
#  if HAVE_GETEUID
  if (geteuid () != saved_uid)
    abort ();
#  endif
  if (getuid () != uid)
    abort ();
# endif
# if HAVE_GETRESGID /* glibc, FreeBSD, OpenBSD, HP-UX */
  {
    uid_t real;
    uid_t effective;
    uid_t saved;
    if (getresgid (&real, &effective, &saved) < 0
        || real != gid
        || effective != saved_gid
        || saved != saved_gid)
      abort ();
  }
# else
#  if HAVE_GETEGID
  if (getegid () != saved_gid)
    abort ();
#  endif
  if (getgid () != gid)
    abort ();
# endif

  return 0;
#else
  errno = ENOSYS;
  return -1;
#endif
}

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kc3-lang/gnulib/lib/idpriv-droptemp.c

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lib/idpriv-droptemp.c