mirror_zfs/module/os/linux/spl/spl-cred.c
youzhongyang f0aca5f7bb Linux 6.3 compat: idmapped mount API changes
Linux kernel 6.3 changed a bunch of APIs to use the dedicated idmap
type for mounts (struct mnt_idmap), we need to detect these changes
and make zfs work with the new APIs.

NOTE: This backport only includes the configure checks to detect
the 6.3 idmap API changes.  It does not include support for idmap.
When provided the idmap variable is ignored in most case in the
same way the user_ns argument was ignored.  This change is solely
to provide compatibility with the new interfaces.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Youzhong Yang <yyang@mathworks.com>
Closes #14682
2023-06-05 10:59:02 -07:00

168 lines
3.6 KiB
C

/*
* Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
* Copyright (C) 2007 The Regents of the University of California.
* Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
* Written by Brian Behlendorf <behlendorf1@llnl.gov>.
* UCRL-CODE-235197
*
* This file is part of the SPL, Solaris Porting Layer.
*
* The SPL 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 2 of the License, or (at your
* option) any later version.
*
* The SPL 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 the SPL. If not, see <http://www.gnu.org/licenses/>.
*
* Solaris Porting Layer (SPL) Credential Implementation.
*/
#include <sys/cred.h>
static int
cr_groups_search(const struct group_info *group_info, kgid_t grp)
{
unsigned int left, right, mid;
int cmp;
if (!group_info)
return (0);
left = 0;
right = group_info->ngroups;
while (left < right) {
mid = (left + right) / 2;
cmp = KGID_TO_SGID(grp) -
KGID_TO_SGID(GROUP_AT(group_info, mid));
if (cmp > 0)
left = mid + 1;
else if (cmp < 0)
right = mid;
else
return (1);
}
return (0);
}
/* Hold a reference on the credential */
void
crhold(cred_t *cr)
{
(void) get_cred((const cred_t *)cr);
}
/* Free a reference on the credential */
void
crfree(cred_t *cr)
{
put_cred((const cred_t *)cr);
}
/* Return the number of supplemental groups */
int
crgetngroups(const cred_t *cr)
{
struct group_info *gi;
int rc;
gi = cr->group_info;
rc = gi->ngroups;
#ifndef HAVE_GROUP_INFO_GID
/*
* For Linux <= 4.8,
* crgetgroups will only returns gi->blocks[0], which contains only
* the first NGROUPS_PER_BLOCK groups.
*/
if (rc > NGROUPS_PER_BLOCK) {
WARN_ON_ONCE(1);
rc = NGROUPS_PER_BLOCK;
}
#endif
return (rc);
}
/*
* Return an array of supplemental gids. The returned address is safe
* to use as long as the caller has taken a reference with crhold().
*
* Linux 4.9 API change, group_info changed from 2d array via ->blocks to 1d
* array via ->gid.
*/
gid_t *
crgetgroups(const cred_t *cr)
{
struct group_info *gi;
gid_t *gids = NULL;
gi = cr->group_info;
#ifdef HAVE_GROUP_INFO_GID
gids = KGIDP_TO_SGIDP(gi->gid);
#else
if (gi->nblocks > 0)
gids = KGIDP_TO_SGIDP(gi->blocks[0]);
#endif
return (gids);
}
/* Check if the passed gid is available in supplied credential. */
int
groupmember(gid_t gid, const cred_t *cr)
{
struct group_info *gi;
int rc;
gi = cr->group_info;
rc = cr_groups_search(gi, SGID_TO_KGID(gid));
return (rc);
}
/* Return the effective user id */
uid_t
crgetuid(const cred_t *cr)
{
return (KUID_TO_SUID(cr->fsuid));
}
/* Return the real user id */
uid_t
crgetruid(const cred_t *cr)
{
return (KUID_TO_SUID(cr->uid));
}
/* Return the effective group id */
gid_t
crgetgid(const cred_t *cr)
{
return (KGID_TO_SGID(cr->fsgid));
}
/* Return the initial user ns or nop_mnt_idmap */
zidmap_t *
zfs_get_init_idmap(void)
{
#ifdef HAVE_IOPS_CREATE_IDMAP
return ((zidmap_t *)&nop_mnt_idmap);
#else
return ((zidmap_t *)&init_user_ns);
#endif
}
EXPORT_SYMBOL(zfs_get_init_idmap);
EXPORT_SYMBOL(crhold);
EXPORT_SYMBOL(crfree);
EXPORT_SYMBOL(crgetuid);
EXPORT_SYMBOL(crgetruid);
EXPORT_SYMBOL(crgetgid);
EXPORT_SYMBOL(crgetngroups);
EXPORT_SYMBOL(crgetgroups);
EXPORT_SYMBOL(groupmember);