From a3eed2c248067f0319cb72bcc8b5e2c7054ea6dc Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 05:06:57 +0200 Subject: Adding upstream version 1.20.1. Signed-off-by: Daniel Baumann --- lib/getgroups.c | 131 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 131 insertions(+) create mode 100644 lib/getgroups.c (limited to 'lib/getgroups.c') diff --git a/lib/getgroups.c b/lib/getgroups.c new file mode 100644 index 0000000..cd6f4d7 --- /dev/null +++ b/lib/getgroups.c @@ -0,0 +1,131 @@ +/* provide consistent interface to getgroups for systems that don't allow N==0 + + Copyright (C) 1996, 1999, 2003, 2006-2018 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 . */ + +/* written by Jim Meyering */ + +#include + +#include + +#include +#include +#include + +#if !HAVE_GETGROUPS + +/* Provide a stub that fails with ENOSYS, since there is no group + information available on mingw. */ +int +getgroups (int n _GL_UNUSED, GETGROUPS_T *groups _GL_UNUSED) +{ + errno = ENOSYS; + return -1; +} + +#else /* HAVE_GETGROUPS */ + +# undef getgroups +# ifndef GETGROUPS_ZERO_BUG +# define GETGROUPS_ZERO_BUG 0 +# endif + +/* On OS X 10.6 and later, use the usual getgroups, not the one + supplied when _DARWIN_C_SOURCE is defined. _DARWIN_C_SOURCE is + normally defined, since it means "conform to POSIX, but add + non-POSIX extensions even if that violates the POSIX namespace + rules", which is what we normally want. But with getgroups there + is an inconsistency, and _DARWIN_C_SOURCE means "change getgroups() + so that it no longer works right". The BUGS section of compat(5) + says that the behavior is dubious if you compile different sections + of a program with different _DARWIN_C_SOURCE settings, so fix only + the offending symbol. */ +# ifdef __APPLE__ +int posix_getgroups (int, gid_t []) __asm ("_getgroups"); +# define getgroups posix_getgroups +# endif + +/* On at least NeXTstep 3.2, getgroups (0, NULL) always fails. + On other systems, it returns the number of supplemental + groups for the process. This function handles that special case + and lets the system-provided function handle all others. However, + it can fail with ENOMEM if memory is tight. It is unspecified + whether the effective group id is included in the list. */ + +int +rpl_getgroups (int n, gid_t *group) +{ + int n_groups; + GETGROUPS_T *gbuf; + int saved_errno; + + if (n < 0) + { + errno = EINVAL; + return -1; + } + + if (n != 0 || !GETGROUPS_ZERO_BUG) + { + int result; + if (sizeof *group == sizeof *gbuf) + return getgroups (n, (GETGROUPS_T *) group); + + if (SIZE_MAX / sizeof *gbuf <= n) + { + errno = ENOMEM; + return -1; + } + gbuf = malloc (n * sizeof *gbuf); + if (!gbuf) + return -1; + result = getgroups (n, gbuf); + if (0 <= result) + { + n = result; + while (n--) + group[n] = gbuf[n]; + } + saved_errno = errno; + free (gbuf); + errno = saved_errno; + return result; + } + + n = 20; + while (1) + { + /* No need to worry about address arithmetic overflow here, + since the ancient systems that we're running on have low + limits on the number of secondary groups. */ + gbuf = malloc (n * sizeof *gbuf); + if (!gbuf) + return -1; + n_groups = getgroups (n, gbuf); + if (n_groups == -1 ? errno != EINVAL : n_groups < n) + break; + free (gbuf); + n *= 2; + } + + saved_errno = errno; + free (gbuf); + errno = saved_errno; + + return n_groups; +} + +#endif /* HAVE_GETGROUPS */ -- cgit v1.2.3