satip-axe/kernel/fs/nfsd/nfs4idmap.c
2015-03-26 17:24:57 +01:00

685 lines
15 KiB
C

/*
* fs/nfsd/nfs4idmap.c
*
* Mapping of UID/GIDs to name and vice versa.
*
* Copyright (c) 2002, 2003 The Regents of the University of
* Michigan. All rights reserved.
*
* Marius Aamodt Eriksen <marius@umich.edu>
*
* 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. Neither the name of the University nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``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 REGENTS 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 <linux/module.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfs.h>
#include <linux/nfs4.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_page.h>
#include <linux/sunrpc/cache.h>
#include <linux/nfsd_idmap.h>
#include <linux/list.h>
#include <linux/time.h>
#include <linux/seq_file.h>
#include <linux/sunrpc/svcauth.h>
/*
* Cache entry
*/
/*
* XXX we know that IDMAP_NAMESZ < PAGE_SIZE, but it's ugly to rely on
* that.
*/
#define IDMAP_TYPE_USER 0
#define IDMAP_TYPE_GROUP 1
struct ent {
struct cache_head h;
int type; /* User / Group */
uid_t id;
char name[IDMAP_NAMESZ];
char authname[IDMAP_NAMESZ];
};
/* Common entry handling */
#define ENT_HASHBITS 8
#define ENT_HASHMAX (1 << ENT_HASHBITS)
#define ENT_HASHMASK (ENT_HASHMAX - 1)
static void
ent_init(struct cache_head *cnew, struct cache_head *citm)
{
struct ent *new = container_of(cnew, struct ent, h);
struct ent *itm = container_of(citm, struct ent, h);
new->id = itm->id;
new->type = itm->type;
strlcpy(new->name, itm->name, sizeof(new->name));
strlcpy(new->authname, itm->authname, sizeof(new->name));
}
static void
ent_put(struct kref *ref)
{
struct ent *map = container_of(ref, struct ent, h.ref);
kfree(map);
}
static struct cache_head *
ent_alloc(void)
{
struct ent *e = kmalloc(sizeof(*e), GFP_KERNEL);
if (e)
return &e->h;
else
return NULL;
}
/*
* ID -> Name cache
*/
static struct cache_head *idtoname_table[ENT_HASHMAX];
static uint32_t
idtoname_hash(struct ent *ent)
{
uint32_t hash;
hash = hash_str(ent->authname, ENT_HASHBITS);
hash = hash_long(hash ^ ent->id, ENT_HASHBITS);
/* Flip LSB for user/group */
if (ent->type == IDMAP_TYPE_GROUP)
hash ^= 1;
return hash;
}
static void
idtoname_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
int *blen)
{
struct ent *ent = container_of(ch, struct ent, h);
char idstr[11];
qword_add(bpp, blen, ent->authname);
snprintf(idstr, sizeof(idstr), "%u", ent->id);
qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
qword_add(bpp, blen, idstr);
(*bpp)[-1] = '\n';
}
static int
idtoname_upcall(struct cache_detail *cd, struct cache_head *ch)
{
return sunrpc_cache_pipe_upcall(cd, ch, idtoname_request);
}
static int
idtoname_match(struct cache_head *ca, struct cache_head *cb)
{
struct ent *a = container_of(ca, struct ent, h);
struct ent *b = container_of(cb, struct ent, h);
return (a->id == b->id && a->type == b->type &&
strcmp(a->authname, b->authname) == 0);
}
static int
idtoname_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
{
struct ent *ent;
if (h == NULL) {
seq_puts(m, "#domain type id [name]\n");
return 0;
}
ent = container_of(h, struct ent, h);
seq_printf(m, "%s %s %u", ent->authname,
ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
ent->id);
if (test_bit(CACHE_VALID, &h->flags))
seq_printf(m, " %s", ent->name);
seq_printf(m, "\n");
return 0;
}
static void
warn_no_idmapd(struct cache_detail *detail, int has_died)
{
printk("nfsd: nfsv4 idmapping failing: has idmapd %s?\n",
has_died ? "died" : "not been started");
}
static int idtoname_parse(struct cache_detail *, char *, int);
static struct ent *idtoname_lookup(struct ent *);
static struct ent *idtoname_update(struct ent *, struct ent *);
static struct cache_detail idtoname_cache = {
.owner = THIS_MODULE,
.hash_size = ENT_HASHMAX,
.hash_table = idtoname_table,
.name = "nfs4.idtoname",
.cache_put = ent_put,
.cache_upcall = idtoname_upcall,
.cache_parse = idtoname_parse,
.cache_show = idtoname_show,
.warn_no_listener = warn_no_idmapd,
.match = idtoname_match,
.init = ent_init,
.update = ent_init,
.alloc = ent_alloc,
};
static int
idtoname_parse(struct cache_detail *cd, char *buf, int buflen)
{
struct ent ent, *res;
char *buf1, *bp;
int len;
int error = -EINVAL;
if (buf[buflen - 1] != '\n')
return (-EINVAL);
buf[buflen - 1]= '\0';
buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (buf1 == NULL)
return (-ENOMEM);
memset(&ent, 0, sizeof(ent));
/* Authentication name */
if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
goto out;
memcpy(ent.authname, buf1, sizeof(ent.authname));
/* Type */
if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
goto out;
ent.type = strcmp(buf1, "user") == 0 ?
IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
/* ID */
if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
goto out;
ent.id = simple_strtoul(buf1, &bp, 10);
if (bp == buf1)
goto out;
/* expiry */
ent.h.expiry_time = get_expiry(&buf);
if (ent.h.expiry_time == 0)
goto out;
error = -ENOMEM;
res = idtoname_lookup(&ent);
if (!res)
goto out;
/* Name */
error = -EINVAL;
len = qword_get(&buf, buf1, PAGE_SIZE);
if (len < 0)
goto out;
if (len == 0)
set_bit(CACHE_NEGATIVE, &ent.h.flags);
else if (len >= IDMAP_NAMESZ)
goto out;
else
memcpy(ent.name, buf1, sizeof(ent.name));
error = -ENOMEM;
res = idtoname_update(&ent, res);
if (res == NULL)
goto out;
cache_put(&res->h, &idtoname_cache);
error = 0;
out:
kfree(buf1);
return error;
}
static struct ent *
idtoname_lookup(struct ent *item)
{
struct cache_head *ch = sunrpc_cache_lookup(&idtoname_cache,
&item->h,
idtoname_hash(item));
if (ch)
return container_of(ch, struct ent, h);
else
return NULL;
}
static struct ent *
idtoname_update(struct ent *new, struct ent *old)
{
struct cache_head *ch = sunrpc_cache_update(&idtoname_cache,
&new->h, &old->h,
idtoname_hash(new));
if (ch)
return container_of(ch, struct ent, h);
else
return NULL;
}
/*
* Name -> ID cache
*/
static struct cache_head *nametoid_table[ENT_HASHMAX];
static inline int
nametoid_hash(struct ent *ent)
{
return hash_str(ent->name, ENT_HASHBITS);
}
static void
nametoid_request(struct cache_detail *cd, struct cache_head *ch, char **bpp,
int *blen)
{
struct ent *ent = container_of(ch, struct ent, h);
qword_add(bpp, blen, ent->authname);
qword_add(bpp, blen, ent->type == IDMAP_TYPE_GROUP ? "group" : "user");
qword_add(bpp, blen, ent->name);
(*bpp)[-1] = '\n';
}
static int
nametoid_upcall(struct cache_detail *cd, struct cache_head *ch)
{
return sunrpc_cache_pipe_upcall(cd, ch, nametoid_request);
}
static int
nametoid_match(struct cache_head *ca, struct cache_head *cb)
{
struct ent *a = container_of(ca, struct ent, h);
struct ent *b = container_of(cb, struct ent, h);
return (a->type == b->type && strcmp(a->name, b->name) == 0 &&
strcmp(a->authname, b->authname) == 0);
}
static int
nametoid_show(struct seq_file *m, struct cache_detail *cd, struct cache_head *h)
{
struct ent *ent;
if (h == NULL) {
seq_puts(m, "#domain type name [id]\n");
return 0;
}
ent = container_of(h, struct ent, h);
seq_printf(m, "%s %s %s", ent->authname,
ent->type == IDMAP_TYPE_GROUP ? "group" : "user",
ent->name);
if (test_bit(CACHE_VALID, &h->flags))
seq_printf(m, " %u", ent->id);
seq_printf(m, "\n");
return 0;
}
static struct ent *nametoid_lookup(struct ent *);
static struct ent *nametoid_update(struct ent *, struct ent *);
static int nametoid_parse(struct cache_detail *, char *, int);
static struct cache_detail nametoid_cache = {
.owner = THIS_MODULE,
.hash_size = ENT_HASHMAX,
.hash_table = nametoid_table,
.name = "nfs4.nametoid",
.cache_put = ent_put,
.cache_upcall = nametoid_upcall,
.cache_parse = nametoid_parse,
.cache_show = nametoid_show,
.warn_no_listener = warn_no_idmapd,
.match = nametoid_match,
.init = ent_init,
.update = ent_init,
.alloc = ent_alloc,
};
static int
nametoid_parse(struct cache_detail *cd, char *buf, int buflen)
{
struct ent ent, *res;
char *buf1;
int error = -EINVAL;
if (buf[buflen - 1] != '\n')
return (-EINVAL);
buf[buflen - 1]= '\0';
buf1 = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (buf1 == NULL)
return (-ENOMEM);
memset(&ent, 0, sizeof(ent));
/* Authentication name */
if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
goto out;
memcpy(ent.authname, buf1, sizeof(ent.authname));
/* Type */
if (qword_get(&buf, buf1, PAGE_SIZE) <= 0)
goto out;
ent.type = strcmp(buf1, "user") == 0 ?
IDMAP_TYPE_USER : IDMAP_TYPE_GROUP;
/* Name */
error = qword_get(&buf, buf1, PAGE_SIZE);
if (error <= 0 || error >= IDMAP_NAMESZ)
goto out;
memcpy(ent.name, buf1, sizeof(ent.name));
/* expiry */
ent.h.expiry_time = get_expiry(&buf);
if (ent.h.expiry_time == 0)
goto out;
/* ID */
error = get_int(&buf, &ent.id);
if (error == -EINVAL)
goto out;
if (error == -ENOENT)
set_bit(CACHE_NEGATIVE, &ent.h.flags);
error = -ENOMEM;
res = nametoid_lookup(&ent);
if (res == NULL)
goto out;
res = nametoid_update(&ent, res);
if (res == NULL)
goto out;
cache_put(&res->h, &nametoid_cache);
error = 0;
out:
kfree(buf1);
return (error);
}
static struct ent *
nametoid_lookup(struct ent *item)
{
struct cache_head *ch = sunrpc_cache_lookup(&nametoid_cache,
&item->h,
nametoid_hash(item));
if (ch)
return container_of(ch, struct ent, h);
else
return NULL;
}
static struct ent *
nametoid_update(struct ent *new, struct ent *old)
{
struct cache_head *ch = sunrpc_cache_update(&nametoid_cache,
&new->h, &old->h,
nametoid_hash(new));
if (ch)
return container_of(ch, struct ent, h);
else
return NULL;
}
/*
* Exported API
*/
int
nfsd_idmap_init(void)
{
int rv;
rv = cache_register(&idtoname_cache);
if (rv)
return rv;
rv = cache_register(&nametoid_cache);
if (rv)
cache_unregister(&idtoname_cache);
return rv;
}
void
nfsd_idmap_shutdown(void)
{
cache_unregister(&idtoname_cache);
cache_unregister(&nametoid_cache);
}
/*
* Deferred request handling
*/
struct idmap_defer_req {
struct cache_req req;
struct cache_deferred_req deferred_req;
wait_queue_head_t waitq;
atomic_t count;
};
static inline void
put_mdr(struct idmap_defer_req *mdr)
{
if (atomic_dec_and_test(&mdr->count))
kfree(mdr);
}
static inline void
get_mdr(struct idmap_defer_req *mdr)
{
atomic_inc(&mdr->count);
}
static void
idmap_revisit(struct cache_deferred_req *dreq, int toomany)
{
struct idmap_defer_req *mdr =
container_of(dreq, struct idmap_defer_req, deferred_req);
wake_up(&mdr->waitq);
put_mdr(mdr);
}
static struct cache_deferred_req *
idmap_defer(struct cache_req *req)
{
struct idmap_defer_req *mdr =
container_of(req, struct idmap_defer_req, req);
mdr->deferred_req.revisit = idmap_revisit;
get_mdr(mdr);
return (&mdr->deferred_req);
}
static inline int
do_idmap_lookup(struct ent *(*lookup_fn)(struct ent *), struct ent *key,
struct cache_detail *detail, struct ent **item,
struct idmap_defer_req *mdr)
{
*item = lookup_fn(key);
if (!*item)
return -ENOMEM;
return cache_check(detail, &(*item)->h, &mdr->req);
}
static inline int
do_idmap_lookup_nowait(struct ent *(*lookup_fn)(struct ent *),
struct ent *key, struct cache_detail *detail,
struct ent **item)
{
int ret = -ENOMEM;
*item = lookup_fn(key);
if (!*item)
goto out_err;
ret = -ETIMEDOUT;
if (!test_bit(CACHE_VALID, &(*item)->h.flags)
|| (*item)->h.expiry_time < get_seconds()
|| detail->flush_time > (*item)->h.last_refresh)
goto out_put;
ret = -ENOENT;
if (test_bit(CACHE_NEGATIVE, &(*item)->h.flags))
goto out_put;
return 0;
out_put:
cache_put(&(*item)->h, detail);
out_err:
*item = NULL;
return ret;
}
static int
idmap_lookup(struct svc_rqst *rqstp,
struct ent *(*lookup_fn)(struct ent *), struct ent *key,
struct cache_detail *detail, struct ent **item)
{
struct idmap_defer_req *mdr;
int ret;
mdr = kzalloc(sizeof(*mdr), GFP_KERNEL);
if (!mdr)
return -ENOMEM;
atomic_set(&mdr->count, 1);
init_waitqueue_head(&mdr->waitq);
mdr->req.defer = idmap_defer;
ret = do_idmap_lookup(lookup_fn, key, detail, item, mdr);
if (ret == -EAGAIN) {
wait_event_interruptible_timeout(mdr->waitq,
test_bit(CACHE_VALID, &(*item)->h.flags), 1 * HZ);
ret = do_idmap_lookup_nowait(lookup_fn, key, detail, item);
}
put_mdr(mdr);
return ret;
}
static char *
rqst_authname(struct svc_rqst *rqstp)
{
struct auth_domain *clp;
clp = rqstp->rq_gssclient ? rqstp->rq_gssclient : rqstp->rq_client;
return clp->name;
}
static int
idmap_name_to_id(struct svc_rqst *rqstp, int type, const char *name, u32 namelen,
uid_t *id)
{
struct ent *item, key = {
.type = type,
};
int ret;
if (namelen + 1 > sizeof(key.name))
return -EINVAL;
memcpy(key.name, name, namelen);
key.name[namelen] = '\0';
strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
ret = idmap_lookup(rqstp, nametoid_lookup, &key, &nametoid_cache, &item);
if (ret == -ENOENT)
ret = -ESRCH; /* nfserr_badname */
if (ret)
return ret;
*id = item->id;
cache_put(&item->h, &nametoid_cache);
return 0;
}
static int
idmap_id_to_name(struct svc_rqst *rqstp, int type, uid_t id, char *name)
{
struct ent *item, key = {
.id = id,
.type = type,
};
int ret;
strlcpy(key.authname, rqst_authname(rqstp), sizeof(key.authname));
ret = idmap_lookup(rqstp, idtoname_lookup, &key, &idtoname_cache, &item);
if (ret == -ENOENT)
return sprintf(name, "%u", id);
if (ret)
return ret;
ret = strlen(item->name);
BUG_ON(ret > IDMAP_NAMESZ);
memcpy(name, item->name, ret);
cache_put(&item->h, &idtoname_cache);
return ret;
}
int
nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name, size_t namelen,
__u32 *id)
{
return idmap_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, id);
}
int
nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen,
__u32 *id)
{
return idmap_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, id);
}
int
nfsd_map_uid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
{
return idmap_id_to_name(rqstp, IDMAP_TYPE_USER, id, name);
}
int
nfsd_map_gid_to_name(struct svc_rqst *rqstp, __u32 id, char *name)
{
return idmap_id_to_name(rqstp, IDMAP_TYPE_GROUP, id, name);
}