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Diffstat (limited to 'libmisc/find_new_sub_gids.c')
| -rw-r--r-- | libmisc/find_new_sub_gids.c | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/libmisc/find_new_sub_gids.c b/libmisc/find_new_sub_gids.c new file mode 100644 index 0000000..ae8a937 --- /dev/null +++ b/libmisc/find_new_sub_gids.c @@ -0,0 +1,86 @@ +/* + * Copyright (c) 2012 Eric Biederman + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the copyright holders or contributors may not be used to + * endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A + * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include <config.h> + +#ifdef ENABLE_SUBIDS + +#include <assert.h> +#include <stdio.h> +#include <errno.h> + +#include "prototypes.h" +#include "subordinateio.h" +#include "getdef.h" + +/* + * find_new_sub_gids - Find a new unused range of GIDs. + * + * If successful, find_new_sub_gids provides a range of unused + * user IDs in the [SUB_GID_MIN:SUB_GID_MAX] range. + * + * Return 0 on success, -1 if no unused GIDs are available. + */ +int find_new_sub_gids (const char *owner, + gid_t *range_start, unsigned long *range_count) +{ + unsigned long min, max; + unsigned long count; + gid_t start; + + assert (range_start != NULL); + assert (range_count != NULL); + + min = getdef_ulong ("SUB_GID_MIN", 100000UL); + max = getdef_ulong ("SUB_GID_MAX", 600100000UL); + count = getdef_ulong ("SUB_GID_COUNT", 65536); + + if (min > max || count >= max || (min + count - 1) > max) { + (void) fprintf (stderr, + _("%s: Invalid configuration: SUB_GID_MIN (%lu)," + " SUB_GID_MAX (%lu), SUB_GID_COUNT (%lu)\n"), + Prog, min, max, count); + return -1; + } + + start = sub_gid_find_free_range(min, max, count); + if (start == (gid_t)-1) { + fprintf (stderr, + _("%s: Can't get unique subordinate GID range\n"), + Prog); + SYSLOG ((LOG_WARN, "no more available subordinate GIDs on the system")); + return -1; + } + *range_start = start; + *range_count = count; + return 0; +} +#else /* !ENABLE_SUBIDS */ +extern int errno; /* warning: ANSI C forbids an empty source file */ +#endif /* !ENABLE_SUBIDS */ + |