1 /*
2 * GPL HEADER START
3 *
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
19 *
20 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21 * CA 95054 USA or visit www.sun.com if you need additional information or
22 * have any questions.
23 *
24 * GPL HEADER END
25 */
26 /*
27 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
29 *
30 * Copyright (c) 2011, 2012, Intel Corporation.
31 */
32 /*
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
35 *
36 * lustre/llite/remote_perm.c
37 *
38 * Lustre Permission Cache for Remote Client
39 *
40 * Author: Lai Siyao <lsy@clusterfs.com>
41 * Author: Fan Yong <fanyong@clusterfs.com>
42 */
43
44 #define DEBUG_SUBSYSTEM S_LLITE
45
46 #include <linux/module.h>
47 #include <linux/types.h>
48
49 #include "../include/lustre_lite.h"
50 #include "../include/lustre_ha.h"
51 #include "../include/lustre_dlm.h"
52 #include "../include/lprocfs_status.h"
53 #include "../include/lustre_disk.h"
54 #include "../include/lustre_param.h"
55 #include "llite_internal.h"
56
57 struct kmem_cache *ll_remote_perm_cachep = NULL;
58 struct kmem_cache *ll_rmtperm_hash_cachep = NULL;
59
alloc_ll_remote_perm(void)60 static inline struct ll_remote_perm *alloc_ll_remote_perm(void)
61 {
62 struct ll_remote_perm *lrp;
63
64 OBD_SLAB_ALLOC_PTR_GFP(lrp, ll_remote_perm_cachep, GFP_KERNEL);
65 if (lrp)
66 INIT_HLIST_NODE(&lrp->lrp_list);
67 return lrp;
68 }
69
free_ll_remote_perm(struct ll_remote_perm * lrp)70 static inline void free_ll_remote_perm(struct ll_remote_perm *lrp)
71 {
72 if (!lrp)
73 return;
74
75 if (!hlist_unhashed(&lrp->lrp_list))
76 hlist_del(&lrp->lrp_list);
77 OBD_SLAB_FREE(lrp, ll_remote_perm_cachep, sizeof(*lrp));
78 }
79
alloc_rmtperm_hash(void)80 static struct hlist_head *alloc_rmtperm_hash(void)
81 {
82 struct hlist_head *hash;
83 int i;
84
85 OBD_SLAB_ALLOC_GFP(hash, ll_rmtperm_hash_cachep,
86 REMOTE_PERM_HASHSIZE * sizeof(*hash),
87 GFP_IOFS);
88 if (!hash)
89 return NULL;
90
91 for (i = 0; i < REMOTE_PERM_HASHSIZE; i++)
92 INIT_HLIST_HEAD(hash + i);
93
94 return hash;
95 }
96
free_rmtperm_hash(struct hlist_head * hash)97 void free_rmtperm_hash(struct hlist_head *hash)
98 {
99 int i;
100 struct ll_remote_perm *lrp;
101 struct hlist_node *next;
102
103 if (!hash)
104 return;
105
106 for (i = 0; i < REMOTE_PERM_HASHSIZE; i++)
107 hlist_for_each_entry_safe(lrp, next, hash + i,
108 lrp_list)
109 free_ll_remote_perm(lrp);
110 OBD_SLAB_FREE(hash, ll_rmtperm_hash_cachep,
111 REMOTE_PERM_HASHSIZE * sizeof(*hash));
112 }
113
remote_perm_hashfunc(uid_t uid)114 static inline int remote_perm_hashfunc(uid_t uid)
115 {
116 return uid & (REMOTE_PERM_HASHSIZE - 1);
117 }
118
119 /* NB: setxid permission is not checked here, instead it's done on
120 * MDT when client get remote permission. */
do_check_remote_perm(struct ll_inode_info * lli,int mask)121 static int do_check_remote_perm(struct ll_inode_info *lli, int mask)
122 {
123 struct hlist_head *head;
124 struct ll_remote_perm *lrp;
125 int found = 0, rc;
126
127 if (!lli->lli_remote_perms)
128 return -ENOENT;
129
130 head = lli->lli_remote_perms +
131 remote_perm_hashfunc(from_kuid(&init_user_ns, current_uid()));
132
133 spin_lock(&lli->lli_lock);
134 hlist_for_each_entry(lrp, head, lrp_list) {
135 if (lrp->lrp_uid != from_kuid(&init_user_ns, current_uid()))
136 continue;
137 if (lrp->lrp_gid != from_kgid(&init_user_ns, current_gid()))
138 continue;
139 if (lrp->lrp_fsuid != from_kuid(&init_user_ns, current_fsuid()))
140 continue;
141 if (lrp->lrp_fsgid != from_kgid(&init_user_ns, current_fsgid()))
142 continue;
143 found = 1;
144 break;
145 }
146
147 if (!found) {
148 rc = -ENOENT;
149 goto out;
150 }
151
152 CDEBUG(D_SEC, "found remote perm: %u/%u/%u/%u - %#x\n",
153 lrp->lrp_uid, lrp->lrp_gid, lrp->lrp_fsuid, lrp->lrp_fsgid,
154 lrp->lrp_access_perm);
155 rc = ((lrp->lrp_access_perm & mask) == mask) ? 0 : -EACCES;
156
157 out:
158 spin_unlock(&lli->lli_lock);
159 return rc;
160 }
161
ll_update_remote_perm(struct inode * inode,struct mdt_remote_perm * perm)162 int ll_update_remote_perm(struct inode *inode, struct mdt_remote_perm *perm)
163 {
164 struct ll_inode_info *lli = ll_i2info(inode);
165 struct ll_remote_perm *lrp = NULL, *tmp = NULL;
166 struct hlist_head *head, *perm_hash = NULL;
167
168 LASSERT(ll_i2sbi(inode)->ll_flags & LL_SBI_RMT_CLIENT);
169
170 #if 0
171 if (perm->rp_uid != current->uid ||
172 perm->rp_gid != current->gid ||
173 perm->rp_fsuid != current->fsuid ||
174 perm->rp_fsgid != current->fsgid) {
175 /* user might setxid in this small period */
176 CDEBUG(D_SEC,
177 "remote perm user %u/%u/%u/%u != current %u/%u/%u/%u\n",
178 perm->rp_uid, perm->rp_gid, perm->rp_fsuid,
179 perm->rp_fsgid, current->uid, current->gid,
180 current->fsuid, current->fsgid);
181 return -EAGAIN;
182 }
183 #endif
184
185 if (!lli->lli_remote_perms) {
186 perm_hash = alloc_rmtperm_hash();
187 if (perm_hash == NULL) {
188 CERROR("alloc lli_remote_perms failed!\n");
189 return -ENOMEM;
190 }
191 }
192
193 spin_lock(&lli->lli_lock);
194
195 if (!lli->lli_remote_perms)
196 lli->lli_remote_perms = perm_hash;
197 else
198 free_rmtperm_hash(perm_hash);
199
200 head = lli->lli_remote_perms + remote_perm_hashfunc(perm->rp_uid);
201
202 again:
203 hlist_for_each_entry(tmp, head, lrp_list) {
204 if (tmp->lrp_uid != perm->rp_uid)
205 continue;
206 if (tmp->lrp_gid != perm->rp_gid)
207 continue;
208 if (tmp->lrp_fsuid != perm->rp_fsuid)
209 continue;
210 if (tmp->lrp_fsgid != perm->rp_fsgid)
211 continue;
212 free_ll_remote_perm(lrp);
213 lrp = tmp;
214 break;
215 }
216
217 if (!lrp) {
218 spin_unlock(&lli->lli_lock);
219 lrp = alloc_ll_remote_perm();
220 if (!lrp) {
221 CERROR("alloc memory for ll_remote_perm failed!\n");
222 return -ENOMEM;
223 }
224 spin_lock(&lli->lli_lock);
225 goto again;
226 }
227
228 lrp->lrp_access_perm = perm->rp_access_perm;
229 if (lrp != tmp) {
230 lrp->lrp_uid = perm->rp_uid;
231 lrp->lrp_gid = perm->rp_gid;
232 lrp->lrp_fsuid = perm->rp_fsuid;
233 lrp->lrp_fsgid = perm->rp_fsgid;
234 hlist_add_head(&lrp->lrp_list, head);
235 }
236 lli->lli_rmtperm_time = cfs_time_current();
237 spin_unlock(&lli->lli_lock);
238
239 CDEBUG(D_SEC, "new remote perm@%p: %u/%u/%u/%u - %#x\n",
240 lrp, lrp->lrp_uid, lrp->lrp_gid, lrp->lrp_fsuid, lrp->lrp_fsgid,
241 lrp->lrp_access_perm);
242
243 return 0;
244 }
245
lustre_check_remote_perm(struct inode * inode,int mask)246 int lustre_check_remote_perm(struct inode *inode, int mask)
247 {
248 struct ll_inode_info *lli = ll_i2info(inode);
249 struct ll_sb_info *sbi = ll_i2sbi(inode);
250 struct ptlrpc_request *req = NULL;
251 struct mdt_remote_perm *perm;
252 struct obd_capa *oc;
253 unsigned long save;
254 int i = 0, rc;
255
256 do {
257 save = lli->lli_rmtperm_time;
258 rc = do_check_remote_perm(lli, mask);
259 if (!rc || (rc != -ENOENT && i))
260 break;
261
262 might_sleep();
263
264 mutex_lock(&lli->lli_rmtperm_mutex);
265 /* check again */
266 if (save != lli->lli_rmtperm_time) {
267 rc = do_check_remote_perm(lli, mask);
268 if (!rc || (rc != -ENOENT && i)) {
269 mutex_unlock(&lli->lli_rmtperm_mutex);
270 break;
271 }
272 }
273
274 if (i++ > 5) {
275 CERROR("check remote perm falls in dead loop!\n");
276 LBUG();
277 }
278
279 oc = ll_mdscapa_get(inode);
280 rc = md_get_remote_perm(sbi->ll_md_exp, ll_inode2fid(inode), oc,
281 ll_i2suppgid(inode), &req);
282 capa_put(oc);
283 if (rc) {
284 mutex_unlock(&lli->lli_rmtperm_mutex);
285 break;
286 }
287
288 perm = req_capsule_server_swab_get(&req->rq_pill, &RMF_ACL,
289 lustre_swab_mdt_remote_perm);
290 if (unlikely(perm == NULL)) {
291 mutex_unlock(&lli->lli_rmtperm_mutex);
292 rc = -EPROTO;
293 break;
294 }
295
296 rc = ll_update_remote_perm(inode, perm);
297 mutex_unlock(&lli->lli_rmtperm_mutex);
298 if (rc == -ENOMEM)
299 break;
300
301 ptlrpc_req_finished(req);
302 req = NULL;
303 } while (1);
304 ptlrpc_req_finished(req);
305 return rc;
306 }
307
308 #if 0 /* NB: remote perms can't be freed in ll_mdc_blocking_ast of UPDATE lock,
309 * because it will fail sanity test 48.
310 */
311 void ll_free_remote_perms(struct inode *inode)
312 {
313 struct ll_inode_info *lli = ll_i2info(inode);
314 struct hlist_head *hash = lli->lli_remote_perms;
315 struct ll_remote_perm *lrp;
316 struct hlist_node *node, *next;
317 int i;
318
319 LASSERT(hash);
320
321 spin_lock(&lli->lli_lock);
322
323 for (i = 0; i < REMOTE_PERM_HASHSIZE; i++) {
324 hlist_for_each_entry_safe(lrp, node, next, hash + i,
325 lrp_list)
326 free_ll_remote_perm(lrp);
327 }
328
329 spin_unlock(&lli->lli_lock);
330 }
331 #endif
332