blob: 204438cc914ea522b83907aaf618bb0dbcfa4068 [file] [log] [blame]
/* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> */
#include <linux/sched.h>
#include <linux/user_namespace.h>
#include "nfsd.h"
#include "auth.h"
int nfsexp_flags(struct svc_rqst *rqstp, struct svc_export *exp)
{
struct exp_flavor_info *f;
struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
for (f = exp->ex_flavors; f < end; f++) {
if (f->pseudoflavor == rqstp->rq_flavor)
return f->flags;
}
return exp->ex_flags;
}
int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp)
{
struct group_info *rqgi;
struct group_info *gi;
struct cred *new;
int i;
int flags = nfsexp_flags(rqstp, exp);
int ret;
validate_process_creds();
/* discard any old override before preparing the new set */
revert_creds(get_cred(current->real_cred));
new = prepare_creds();
if (!new)
return -ENOMEM;
new->fsuid = rqstp->rq_cred.cr_uid;
new->fsgid = rqstp->rq_cred.cr_gid;
rqgi = rqstp->rq_cred.cr_group_info;
if (flags & NFSEXP_ALLSQUASH) {
new->fsuid = exp->ex_anon_uid;
new->fsgid = exp->ex_anon_gid;
gi = groups_alloc(0);
if (!gi)
goto oom;
} else if (flags & NFSEXP_ROOTSQUASH) {
if (!new->fsuid)
new->fsuid = exp->ex_anon_uid;
if (!new->fsgid)
new->fsgid = exp->ex_anon_gid;
gi = groups_alloc(rqgi->ngroups);
if (!gi)
goto oom;
for (i = 0; i < rqgi->ngroups; i++) {
if (gid_eq(GLOBAL_ROOT_GID, GROUP_AT(rqgi, i)))
GROUP_AT(gi, i) = make_kgid(&init_user_ns, exp->ex_anon_gid);
else
GROUP_AT(gi, i) = GROUP_AT(rqgi, i);
}
} else {
gi = get_group_info(rqgi);
}
if (new->fsuid == (uid_t) -1)
new->fsuid = exp->ex_anon_uid;
if (new->fsgid == (gid_t) -1)
new->fsgid = exp->ex_anon_gid;
ret = set_groups(new, gi);
put_group_info(gi);
if (ret < 0)
goto error;
if (new->fsuid)
new->cap_effective = cap_drop_nfsd_set(new->cap_effective);
else
new->cap_effective = cap_raise_nfsd_set(new->cap_effective,
new->cap_permitted);
validate_process_creds();
put_cred(override_creds(new));
put_cred(new);
validate_process_creds();
return 0;
oom:
ret = -ENOMEM;
error:
abort_creds(new);
return ret;
}