xref: /titanic_41/usr/src/uts/common/syscall/acl.c (revision fcf3ce441efd61da9bb2884968af01cb7c1452cc)
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 	if (fp->f_flag & FREVOKED) {
108 		releasef(fdes);
109 		return (set_errno(EBADF));
110 	}
111 
112 	error = cacl(cmd, nentries, aclbufp, fp->f_vnode, &rv);
113 	releasef(fdes);
114 
115 	if (error)
116 		return (set_errno(error));
117 	return (rv);
118 }
119 
120 
121 /*
122  * Common code for acl() and facl().
123  */
124 static int
125 cacl(int cmd, int nentries, void *aclbufp, vnode_t *vp, int *rv)
126 {
127 	int		error;
128 	int		aclbsize;	/* size of acl list in bytes */
129 	int		dfaclbsize;	/* size of default acl list in bytes */
130 	int		numacls;
131 	caddr_t		uaddrp;
132 	aclent_t	*aclp, *aaclp;
133 	vsecattr_t	vsecattr;
134 	size_t		entry_size;
135 
136 	ASSERT(vp);
137 
138 	bzero(&vsecattr, sizeof (vsecattr_t));
139 
140 	switch (cmd) {
141 
142 	case ACE_GETACLCNT:
143 	case GETACLCNT:
144 		if (cmd == GETACLCNT) {
145 			entry_size = sizeof (aclent_t);
146 			vsecattr.vsa_mask = VSA_ACLCNT | VSA_DFACLCNT;
147 		} else {
148 			entry_size = sizeof (ace_t);
149 			vsecattr.vsa_mask = VSA_ACECNT;
150 		}
151 		if (error = VOP_GETSECATTR(vp, &vsecattr, 0, CRED(), NULL))
152 			return (error);
153 		*rv = vsecattr.vsa_aclcnt + vsecattr.vsa_dfaclcnt;
154 		if (vsecattr.vsa_aclcnt && vsecattr.vsa_aclentp) {
155 			kmem_free(vsecattr.vsa_aclentp,
156 			    vsecattr.vsa_aclcnt * entry_size);
157 		}
158 		if (vsecattr.vsa_dfaclcnt && vsecattr.vsa_dfaclentp) {
159 			kmem_free(vsecattr.vsa_dfaclentp,
160 			    vsecattr.vsa_dfaclcnt * entry_size);
161 		}
162 		break;
163 	case GETACL:
164 		/*
165 		 * Minimum ACL size is three entries so might as well
166 		 * bail out here.
167 		 */
168 		if (nentries < 3)
169 			return (EINVAL);
170 		/*
171 		 * NULL output buffer is also a pretty easy bail out.
172 		 */
173 		if (aclbufp == NULL)
174 			return (EFAULT);
175 		vsecattr.vsa_mask = VSA_ACL | VSA_ACLCNT | VSA_DFACL |
176 		    VSA_DFACLCNT;
177 		if (error = VOP_GETSECATTR(vp, &vsecattr, 0, CRED(), NULL))
178 			return (error);
179 		/* Check user's buffer is big enough */
180 		numacls = vsecattr.vsa_aclcnt + vsecattr.vsa_dfaclcnt;
181 		aclbsize = vsecattr.vsa_aclcnt * sizeof (aclent_t);
182 		dfaclbsize = vsecattr.vsa_dfaclcnt * sizeof (aclent_t);
183 		if (numacls > nentries) {
184 			error = ENOSPC;
185 			goto errout;
186 		}
187 		/* Sort the acl & default acl lists */
188 		if (vsecattr.vsa_aclcnt > 1)
189 			ksort((caddr_t)vsecattr.vsa_aclentp,
190 			    vsecattr.vsa_aclcnt, sizeof (aclent_t), cmp2acls);
191 		if (vsecattr.vsa_dfaclcnt > 1)
192 			ksort((caddr_t)vsecattr.vsa_dfaclentp,
193 			    vsecattr.vsa_dfaclcnt, sizeof (aclent_t), cmp2acls);
194 		/* Copy out acl's */
195 		uaddrp = (caddr_t)aclbufp;
196 		if (aclbsize > 0) {	/* bug #1262490 */
197 			if (copyout(vsecattr.vsa_aclentp, uaddrp, aclbsize)) {
198 				error = EFAULT;
199 				goto errout;
200 			}
201 		}
202 		/* Copy out default acl's */
203 		if (dfaclbsize > 0) {
204 			uaddrp += aclbsize;
205 			if (copyout(vsecattr.vsa_dfaclentp,
206 			    uaddrp, dfaclbsize)) {
207 				error = EFAULT;
208 				goto errout;
209 			}
210 		}
211 		*rv = numacls;
212 		if (vsecattr.vsa_aclcnt) {
213 			kmem_free(vsecattr.vsa_aclentp,
214 			    vsecattr.vsa_aclcnt * sizeof (aclent_t));
215 		}
216 		if (vsecattr.vsa_dfaclcnt) {
217 			kmem_free(vsecattr.vsa_dfaclentp,
218 			    vsecattr.vsa_dfaclcnt * sizeof (aclent_t));
219 		}
220 		break;
221 
222 	case ACE_GETACL:
223 		if (aclbufp == NULL)
224 			return (EFAULT);
225 
226 		vsecattr.vsa_mask = VSA_ACE | VSA_ACECNT;
227 		if (error = VOP_GETSECATTR(vp, &vsecattr, 0, CRED(), NULL))
228 			return (error);
229 
230 		aclbsize = vsecattr.vsa_aclcnt * sizeof (ace_t);
231 		if (vsecattr.vsa_aclcnt > nentries) {
232 			error = ENOSPC;
233 			goto errout;
234 		}
235 
236 		if (aclbsize > 0) {
237 			if ((error = copyout(vsecattr.vsa_aclentp,
238 			    aclbufp, aclbsize)) != 0) {
239 				goto errout;
240 			}
241 		}
242 
243 		*rv = vsecattr.vsa_aclcnt;
244 		if (vsecattr.vsa_aclcnt) {
245 			kmem_free(vsecattr.vsa_aclentp, vsecattr.vsa_aclentsz);
246 		}
247 		break;
248 
249 	case SETACL:
250 		/*
251 		 * Minimum ACL size is three entries so might as well
252 		 * bail out here.  Also limit request size to prevent user
253 		 * from allocating too much kernel memory.  Maximum size
254 		 * is MAX_ACL_ENTRIES for the ACL part and MAX_ACL_ENTRIES
255 		 * for the default ACL part. (bug 4058667)
256 		 */
257 		if (nentries < 3 || nentries > (MAX_ACL_ENTRIES * 2))
258 			return (EINVAL);
259 		/*
260 		 * NULL output buffer is also an easy bail out.
261 		 */
262 		if (aclbufp == NULL)
263 			return (EFAULT);
264 		vsecattr.vsa_mask = VSA_ACL;
265 		aclbsize = nentries * sizeof (aclent_t);
266 		vsecattr.vsa_aclentp = kmem_alloc(aclbsize, KM_SLEEP);
267 		aaclp = vsecattr.vsa_aclentp;
268 		vsecattr.vsa_aclcnt = nentries;
269 		uaddrp = (caddr_t)aclbufp;
270 		if (copyin(uaddrp, vsecattr.vsa_aclentp, aclbsize)) {
271 			kmem_free(aaclp, aclbsize);
272 			return (EFAULT);
273 		}
274 		/* Sort the acl list */
275 		ksort((caddr_t)vsecattr.vsa_aclentp,
276 		    vsecattr.vsa_aclcnt, sizeof (aclent_t), cmp2acls);
277 
278 		/* Break into acl and default acl lists */
279 		for (numacls = 0, aclp = vsecattr.vsa_aclentp;
280 		    numacls < vsecattr.vsa_aclcnt;
281 		    aclp++, numacls++) {
282 			if (aclp->a_type & ACL_DEFAULT)
283 				break;
284 		}
285 
286 		/* Find where defaults start (if any) */
287 		if (numacls < vsecattr.vsa_aclcnt) {
288 			vsecattr.vsa_mask |= VSA_DFACL;
289 			vsecattr.vsa_dfaclcnt = nentries - numacls;
290 			vsecattr.vsa_dfaclentp = aclp;
291 			vsecattr.vsa_aclcnt = numacls;
292 		}
293 		/* Adjust if they're all defaults */
294 		if (vsecattr.vsa_aclcnt == 0) {
295 			vsecattr.vsa_mask &= ~VSA_ACL;
296 			vsecattr.vsa_aclentp = NULL;
297 		}
298 		/* Only directories can have defaults */
299 		if (vsecattr.vsa_dfaclcnt && vp->v_type != VDIR) {
300 			kmem_free(aaclp, aclbsize);
301 			return (ENOTDIR);
302 		}
303 		(void) VOP_RWLOCK(vp, V_WRITELOCK_TRUE, NULL);
304 		if (error = VOP_SETSECATTR(vp, &vsecattr, 0, CRED(), NULL)) {
305 			kmem_free(aaclp, aclbsize);
306 			VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
307 			return (error);
308 		}
309 
310 		/*
311 		 * Should return 0 upon success according to the man page
312 		 * and SVR4 semantics. (Bug #1214399: SETACL returns wrong rc)
313 		 */
314 		*rv = 0;
315 		kmem_free(aaclp, aclbsize);
316 		VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
317 		break;
318 
319 	case ACE_SETACL:
320 		if (nentries < 1 || nentries > MAX_ACL_ENTRIES)
321 			return (EINVAL);
322 
323 		if (aclbufp == NULL)
324 			return (EFAULT);
325 
326 		vsecattr.vsa_mask = VSA_ACE;
327 		aclbsize = nentries * sizeof (ace_t);
328 		vsecattr.vsa_aclentp = kmem_alloc(aclbsize, KM_SLEEP);
329 		aaclp = vsecattr.vsa_aclentp;
330 		vsecattr.vsa_aclcnt = nentries;
331 		vsecattr.vsa_aclentsz = aclbsize;
332 		uaddrp = (caddr_t)aclbufp;
333 		if (copyin(uaddrp, vsecattr.vsa_aclentp, aclbsize)) {
334 			kmem_free(aaclp, aclbsize);
335 			return (EFAULT);
336 		}
337 		(void) VOP_RWLOCK(vp, V_WRITELOCK_TRUE, NULL);
338 		if (error = VOP_SETSECATTR(vp, &vsecattr, 0, CRED(), NULL)) {
339 			kmem_free(aaclp, aclbsize);
340 			VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
341 			return (error);
342 		}
343 		*rv = 0;
344 		kmem_free(aaclp, aclbsize);
345 		VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
346 		break;
347 
348 	default:
349 		return (EINVAL);
350 	}
351 
352 	return (0);
353 
354 errout:
355 	if (aclbsize && vsecattr.vsa_aclentp)
356 		kmem_free(vsecattr.vsa_aclentp, aclbsize);
357 	if (dfaclbsize && vsecattr.vsa_dfaclentp)
358 		kmem_free(vsecattr.vsa_dfaclentp, dfaclbsize);
359 	return (error);
360 }
361