xref: /titanic_52/usr/src/uts/common/syscall/acl.c (revision 2a9459bdd821c1cf59590a7a9069ac9c591e8a6b)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
27 /*	  All Rights Reserved  	*/
28 
29 /*
30  * Portions of this source code were derived from Berkeley 4.3 BSD
31  * under license from the Regents of the University of California.
32  */
33 
34 #pragma ident	"%Z%%M%	%I%	%E% SMI"
35 
36 #include <sys/param.h>
37 #include <sys/isa_defs.h>
38 #include <sys/types.h>
39 #include <sys/sysmacros.h>
40 #include <sys/cred.h>
41 #include <sys/systm.h>
42 #include <sys/errno.h>
43 #include <sys/fcntl.h>
44 #include <sys/pathname.h>
45 #include <sys/vfs.h>
46 #include <sys/vnode.h>
47 #include <sys/file.h>
48 #include <sys/mode.h>
49 #include <sys/uio.h>
50 #include <sys/kmem.h>
51 #include <sys/filio.h>
52 #include <sys/acl.h>
53 #include <sys/cmn_err.h>
54 #include <acl/acl_common.h>
55 
56 #include <sys/unistd.h>
57 #include <sys/debug.h>
58 #include <fs/fs_subr.h>
59 
60 static int cacl(int cmd, int nentries, void *aclbufp,
61     vnode_t *vp, int *rv);
62 
63 /*
64  * Get/Set ACL of a file.
65  */
66 int
67 acl(const char *fname, int cmd, int nentries, void *aclbufp)
68 {
69 	struct vnode *vp;
70 	int error;
71 	int rv = 0;
72 	int estale_retry = 0;
73 
74 	/* Sanity check arguments */
75 	if (fname == NULL)
76 		return (set_errno(EINVAL));
77 lookup:
78 	error = lookupname((char *)fname, UIO_USERSPACE, FOLLOW, NULLVPP, &vp);
79 	if (error) {
80 		if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
81 			goto lookup;
82 		return (set_errno(error));
83 	}
84 
85 	error = cacl(cmd, nentries, aclbufp, vp, &rv);
86 	VN_RELE(vp);
87 	if (error) {
88 		if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
89 			goto lookup;
90 		return (set_errno(error));
91 	}
92 	return (rv);
93 }
94 
95 /*
96  * Get/Set ACL of a file with facl system call.
97  */
98 int
99 facl(int fdes, int cmd, int nentries, void *aclbufp)
100 {
101 	file_t *fp;
102 	int error;
103 	int rv = 0;
104 
105 	if ((fp = getf(fdes)) == NULL)
106 		return (set_errno(EBADF));
107 #ifdef C2_AUDIT
108 	if (fp->f_flag & FREVOKED) {
109 		releasef(fdes);
110 		return (set_errno(EBADF));
111 	}
112 #endif /* C2_AUDIT */
113 
114 	error = cacl(cmd, nentries, aclbufp, fp->f_vnode, &rv);
115 	releasef(fdes);
116 
117 	if (error)
118 		return (set_errno(error));
119 	return (rv);
120 }
121 
122 
123 /*
124  * Common code for acl() and facl().
125  */
126 static int
127 cacl(int cmd, int nentries, void *aclbufp, vnode_t *vp, int *rv)
128 {
129 	int		error;
130 	int		aclbsize;	/* size of acl list in bytes */
131 	int		dfaclbsize;	/* size of default acl list in bytes */
132 	int		numacls;
133 	caddr_t		uaddrp;
134 	aclent_t	*aclp, *aaclp;
135 	vsecattr_t	vsecattr;
136 	size_t		entry_size;
137 
138 	ASSERT(vp);
139 
140 	bzero(&vsecattr, sizeof (vsecattr_t));
141 
142 	switch (cmd) {
143 
144 	case ACE_GETACLCNT:
145 	case GETACLCNT:
146 		if (cmd == GETACLCNT) {
147 			entry_size = sizeof (aclent_t);
148 			vsecattr.vsa_mask = VSA_ACLCNT | VSA_DFACLCNT;
149 		} else {
150 			entry_size = sizeof (ace_t);
151 			vsecattr.vsa_mask = VSA_ACECNT;
152 		}
153 		if (error = VOP_GETSECATTR(vp, &vsecattr, 0, CRED(), NULL))
154 			return (error);
155 		*rv = vsecattr.vsa_aclcnt + vsecattr.vsa_dfaclcnt;
156 		if (vsecattr.vsa_aclcnt && vsecattr.vsa_aclentp) {
157 			kmem_free(vsecattr.vsa_aclentp,
158 			    vsecattr.vsa_aclcnt * entry_size);
159 		}
160 		if (vsecattr.vsa_dfaclcnt && vsecattr.vsa_dfaclentp) {
161 			kmem_free(vsecattr.vsa_dfaclentp,
162 			    vsecattr.vsa_dfaclcnt * entry_size);
163 		}
164 		break;
165 	case GETACL:
166 		/*
167 		 * Minimum ACL size is three entries so might as well
168 		 * bail out here.
169 		 */
170 		if (nentries < 3)
171 			return (EINVAL);
172 		/*
173 		 * NULL output buffer is also a pretty easy bail out.
174 		 */
175 		if (aclbufp == NULL)
176 			return (EFAULT);
177 		vsecattr.vsa_mask = VSA_ACL | VSA_ACLCNT | VSA_DFACL |
178 		    VSA_DFACLCNT;
179 		if (error = VOP_GETSECATTR(vp, &vsecattr, 0, CRED(), NULL))
180 			return (error);
181 		/* Check user's buffer is big enough */
182 		numacls = vsecattr.vsa_aclcnt + vsecattr.vsa_dfaclcnt;
183 		aclbsize = vsecattr.vsa_aclcnt * sizeof (aclent_t);
184 		dfaclbsize = vsecattr.vsa_dfaclcnt * sizeof (aclent_t);
185 		if (numacls > nentries) {
186 			error = ENOSPC;
187 			goto errout;
188 		}
189 		/* Sort the acl & default acl lists */
190 		if (vsecattr.vsa_aclcnt > 1)
191 			ksort((caddr_t)vsecattr.vsa_aclentp,
192 			vsecattr.vsa_aclcnt, sizeof (aclent_t), cmp2acls);
193 		if (vsecattr.vsa_dfaclcnt > 1)
194 			ksort((caddr_t)vsecattr.vsa_dfaclentp,
195 			vsecattr.vsa_dfaclcnt, sizeof (aclent_t), cmp2acls);
196 		/* Copy out acl's */
197 		uaddrp = (caddr_t)aclbufp;
198 		if (aclbsize > 0) {	/* bug #1262490 */
199 			if (copyout(vsecattr.vsa_aclentp, uaddrp, aclbsize)) {
200 				error = EFAULT;
201 				goto errout;
202 			}
203 		}
204 		/* Copy out default acl's */
205 		if (dfaclbsize > 0) {
206 			uaddrp += aclbsize;
207 			if (copyout(vsecattr.vsa_dfaclentp,
208 			    uaddrp, dfaclbsize)) {
209 				error = EFAULT;
210 				goto errout;
211 			}
212 		}
213 		*rv = numacls;
214 		if (vsecattr.vsa_aclcnt) {
215 			kmem_free(vsecattr.vsa_aclentp,
216 			    vsecattr.vsa_aclcnt * sizeof (aclent_t));
217 		}
218 		if (vsecattr.vsa_dfaclcnt) {
219 			kmem_free(vsecattr.vsa_dfaclentp,
220 			    vsecattr.vsa_dfaclcnt * sizeof (aclent_t));
221 		}
222 		break;
223 
224 	case ACE_GETACL:
225 		if (aclbufp == NULL)
226 			return (EFAULT);
227 
228 		vsecattr.vsa_mask = VSA_ACE | VSA_ACECNT;
229 		if (error = VOP_GETSECATTR(vp, &vsecattr, 0, CRED(), NULL))
230 			return (error);
231 
232 		aclbsize = vsecattr.vsa_aclcnt * sizeof (ace_t);
233 		if (vsecattr.vsa_aclcnt > nentries) {
234 			error = ENOSPC;
235 			goto errout;
236 		}
237 
238 		if (aclbsize > 0) {
239 			if ((error = copyout(vsecattr.vsa_aclentp,
240 			    aclbufp, aclbsize)) != 0) {
241 				goto errout;
242 			}
243 		}
244 
245 		*rv = vsecattr.vsa_aclcnt;
246 		if (vsecattr.vsa_aclcnt) {
247 			kmem_free(vsecattr.vsa_aclentp, vsecattr.vsa_aclentsz);
248 		}
249 		break;
250 
251 	case SETACL:
252 		/*
253 		 * Minimum ACL size is three entries so might as well
254 		 * bail out here.  Also limit request size to prevent user
255 		 * from allocating too much kernel memory.  Maximum size
256 		 * is MAX_ACL_ENTRIES for the ACL part and MAX_ACL_ENTRIES
257 		 * for the default ACL part. (bug 4058667)
258 		 */
259 		if (nentries < 3 || nentries > (MAX_ACL_ENTRIES * 2))
260 			return (EINVAL);
261 		/*
262 		 * NULL output buffer is also an easy bail out.
263 		 */
264 		if (aclbufp == NULL)
265 			return (EFAULT);
266 		vsecattr.vsa_mask = VSA_ACL;
267 		aclbsize = nentries * sizeof (aclent_t);
268 		vsecattr.vsa_aclentp = kmem_alloc(aclbsize, KM_SLEEP);
269 		aaclp = vsecattr.vsa_aclentp;
270 		vsecattr.vsa_aclcnt = nentries;
271 		uaddrp = (caddr_t)aclbufp;
272 		if (copyin(uaddrp, vsecattr.vsa_aclentp, aclbsize)) {
273 			kmem_free(aaclp, aclbsize);
274 			return (EFAULT);
275 		}
276 		/* Sort the acl list */
277 		ksort((caddr_t)vsecattr.vsa_aclentp,
278 		    vsecattr.vsa_aclcnt, sizeof (aclent_t), cmp2acls);
279 
280 		/* Break into acl and default acl lists */
281 		for (numacls = 0, aclp = vsecattr.vsa_aclentp;
282 		    numacls < vsecattr.vsa_aclcnt;
283 		    aclp++, numacls++) {
284 			if (aclp->a_type & ACL_DEFAULT)
285 				break;
286 		}
287 
288 		/* Find where defaults start (if any) */
289 		if (numacls < vsecattr.vsa_aclcnt) {
290 			vsecattr.vsa_mask |= VSA_DFACL;
291 			vsecattr.vsa_dfaclcnt = nentries - numacls;
292 			vsecattr.vsa_dfaclentp = aclp;
293 			vsecattr.vsa_aclcnt = numacls;
294 		}
295 		/* Adjust if they're all defaults */
296 		if (vsecattr.vsa_aclcnt == 0) {
297 			vsecattr.vsa_mask &= ~VSA_ACL;
298 			vsecattr.vsa_aclentp = NULL;
299 		}
300 		/* Only directories can have defaults */
301 		if (vsecattr.vsa_dfaclcnt && vp->v_type != VDIR) {
302 			kmem_free(aaclp, aclbsize);
303 			return (ENOTDIR);
304 		}
305 		(void) VOP_RWLOCK(vp, V_WRITELOCK_TRUE, NULL);
306 		if (error = VOP_SETSECATTR(vp, &vsecattr, 0, CRED(), NULL)) {
307 			kmem_free(aaclp, aclbsize);
308 			VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
309 			return (error);
310 		}
311 
312 		/*
313 		 * Should return 0 upon success according to the man page
314 		 * and SVR4 semantics. (Bug #1214399: SETACL returns wrong rc)
315 		 */
316 		*rv = 0;
317 		kmem_free(aaclp, aclbsize);
318 		VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
319 		break;
320 
321 	case ACE_SETACL:
322 		if (nentries < 1 || nentries > MAX_ACL_ENTRIES)
323 			return (EINVAL);
324 
325 		if (aclbufp == NULL)
326 			return (EFAULT);
327 
328 		vsecattr.vsa_mask = VSA_ACE;
329 		aclbsize = nentries * sizeof (ace_t);
330 		vsecattr.vsa_aclentp = kmem_alloc(aclbsize, KM_SLEEP);
331 		aaclp = vsecattr.vsa_aclentp;
332 		vsecattr.vsa_aclcnt = nentries;
333 		vsecattr.vsa_aclentsz = aclbsize;
334 		uaddrp = (caddr_t)aclbufp;
335 		if (copyin(uaddrp, vsecattr.vsa_aclentp, aclbsize)) {
336 			kmem_free(aaclp, aclbsize);
337 			return (EFAULT);
338 		}
339 		(void) VOP_RWLOCK(vp, V_WRITELOCK_TRUE, NULL);
340 		if (error = VOP_SETSECATTR(vp, &vsecattr, 0, CRED(), NULL)) {
341 			kmem_free(aaclp, aclbsize);
342 			VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
343 			return (error);
344 		}
345 		*rv = 0;
346 		kmem_free(aaclp, aclbsize);
347 		VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
348 		break;
349 
350 	default:
351 		return (EINVAL);
352 	}
353 
354 	return (0);
355 
356 errout:
357 	if (aclbsize && vsecattr.vsa_aclentp)
358 		kmem_free(vsecattr.vsa_aclentp, aclbsize);
359 	if (dfaclbsize && vsecattr.vsa_dfaclentp)
360 		kmem_free(vsecattr.vsa_dfaclentp, dfaclbsize);
361 	return (error);
362 }
363