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-rw-r--r--libmisc/find_new_sub_gids.c86
1 files changed, 86 insertions, 0 deletions
diff --git a/libmisc/find_new_sub_gids.c b/libmisc/find_new_sub_gids.c
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+/*
+ * 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 */
+