65c2617140
- Use an allocation of 65536 uids and gids to allow for POSIX-compliant user owned namespaces. - Don't allocate a uid/gid map to system users. Unfortunately checking for --system isn't quite enough as some distribution wrappers always call useradd without --system and take care of choosing a uid and gid themselves, so also check whether the requested uid/gid is in the user range. This is taken from a patch I wrote for Ubuntu a couple years ago and which somehow didn't make it upstream. Signed-off-by: Stéphane Graber <stgraber@ubuntu.com>
87 lines
3.0 KiB
C
87 lines
3.0 KiB
C
/*
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* Copyright (c) 2012 Eric Biederman
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the copyright holders or contributors may not be used to
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* endorse or promote products derived from this software without
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* specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
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* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <config.h>
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#ifdef ENABLE_SUBIDS
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#include <assert.h>
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#include <stdio.h>
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#include <errno.h>
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#include "prototypes.h"
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#include "subordinateio.h"
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#include "getdef.h"
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/*
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* find_new_sub_uids - Find a new unused range of UIDs.
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*
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* If successful, find_new_sub_uids provides a range of unused
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* user IDs in the [SUB_UID_MIN:SUB_UID_MAX] range.
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*
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* Return 0 on success, -1 if no unused UIDs are available.
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*/
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int find_new_sub_uids (const char *owner,
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uid_t *range_start, unsigned long *range_count)
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{
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unsigned long min, max;
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unsigned long count;
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uid_t start;
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assert (range_start != NULL);
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assert (range_count != NULL);
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min = getdef_ulong ("SUB_UID_MIN", 100000UL);
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max = getdef_ulong ("SUB_UID_MAX", 600100000UL);
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count = getdef_ulong ("SUB_UID_COUNT", 65536);
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if (min > max || count >= max || (min + count - 1) > max) {
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(void) fprintf (stderr,
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_("%s: Invalid configuration: SUB_UID_MIN (%lu),"
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" SUB_UID_MAX (%lu), SUB_UID_COUNT (%lu)\n"),
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Prog, min, max, count);
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return -1;
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}
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start = sub_uid_find_free_range(min, max, count);
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if (start == (uid_t)-1) {
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fprintf (stderr,
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_("%s: Can't get unique subordinate UID range\n"),
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Prog);
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SYSLOG ((LOG_WARN, "no more available subordinate UIDs on the system"));
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return -1;
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}
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*range_start = start;
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*range_count = count;
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return 0;
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}
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#else /* !ENABLE_SUBIDS */
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extern int errno; /* warning: ANSI C forbids an empty source file */
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#endif /* !ENABLE_SUBIDS */
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