xref: /illumos-gate/usr/src/uts/common/syscall/acl.c (revision 1da57d55)
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 #include <sys/param.h>
35 #include <sys/isa_defs.h>
36 #include <sys/types.h>
37 #include <sys/sysmacros.h>
38 #include <sys/cred.h>
39 #include <sys/systm.h>
40 #include <sys/errno.h>
41 #include <sys/fcntl.h>
42 #include <sys/pathname.h>
43 #include <sys/vfs.h>
44 #include <sys/vnode.h>
45 #include <sys/file.h>
46 #include <sys/mode.h>
47 #include <sys/uio.h>
48 #include <sys/kmem.h>
49 #include <sys/filio.h>
50 #include <sys/acl.h>
51 #include <sys/cmn_err.h>
52 #include <acl/acl_common.h>
53 
54 #include <sys/unistd.h>
55 #include <sys/debug.h>
56 #include <fs/fs_subr.h>
57 
58 static int cacl(int cmd, int nentries, void *aclbufp,
59     vnode_t *vp, int *rv);
60 
61 /*
62  * Get/Set ACL of a file.
63  */
64 int
65 acl(const char *fname, int cmd, int nentries, void *aclbufp)
66 {
67 	struct vnode *vp;
68 	int error;
69 	int rv = 0;
70 	int estale_retry = 0;
71 
72 	/* Sanity check arguments */
73 	if (fname == NULL)
74 		return (set_errno(EINVAL));
75 lookup:
76 	error = lookupname((char *)fname, UIO_USERSPACE, FOLLOW, NULLVPP, &vp);
77 	if (error) {
78 		if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
79 			goto lookup;
80 		return (set_errno(error));
81 	}
82 
83 	error = cacl(cmd, nentries, aclbufp, vp, &rv);
84 	VN_RELE(vp);
85 	if (error) {
86 		if ((error == ESTALE) && fs_need_estale_retry(estale_retry++))
87 			goto lookup;
88 		return (set_errno(error));
89 	}
90 	return (rv);
91 }
92 
93 /*
94  * Get/Set ACL of a file with facl system call.
95  */
96 int
97 facl(int fdes, int cmd, int nentries, void *aclbufp)
98 {
99 	file_t *fp;
100 	int error;
101 	int rv = 0;
102 
103 	if ((fp = getf(fdes)) == NULL)
104 		return (set_errno(EBADF));
105 	if (fp->f_flag & FREVOKED) {
106 		releasef(fdes);
107 		return (set_errno(EBADF));
108 	}
109 
110 	error = cacl(cmd, nentries, aclbufp, fp->f_vnode, &rv);
111 	releasef(fdes);
112 
113 	if (error)
114 		return (set_errno(error));
115 	return (rv);
116 }
117 
118 
119 /*
120  * Common code for acl() and facl().
121  */
122 static int
123 cacl(int cmd, int nentries, void *aclbufp, vnode_t *vp, int *rv)
124 {
125 	int		error;
126 	int		aclbsize;	/* size of acl list in bytes */
127 	int		dfaclbsize;	/* size of default acl list in bytes */
128 	int		numacls;
129 	caddr_t		uaddrp;
130 	aclent_t	*aclp, *aaclp;
131 	vsecattr_t	vsecattr;
132 	size_t		entry_size;
133 
134 	ASSERT(vp);
135 
136 	bzero(&vsecattr, sizeof (vsecattr_t));
137 	dfaclbsize = 0;
138 
139 	switch (cmd) {
140 
141 	case ACE_GETACLCNT:
142 	case GETACLCNT:
143 		if (cmd == GETACLCNT) {
144 			entry_size = sizeof (aclent_t);
145 			vsecattr.vsa_mask = VSA_ACLCNT | VSA_DFACLCNT;
146 		} else {
147 			entry_size = sizeof (ace_t);
148 			vsecattr.vsa_mask = VSA_ACECNT;
149 		}
150 		if (error = VOP_GETSECATTR(vp, &vsecattr, 0, CRED(), NULL))
151 			return (error);
152 		*rv = vsecattr.vsa_aclcnt + vsecattr.vsa_dfaclcnt;
153 		if (vsecattr.vsa_aclcnt && vsecattr.vsa_aclentp) {
154 			kmem_free(vsecattr.vsa_aclentp,
155 			    vsecattr.vsa_aclcnt * entry_size);
156 		}
157 		if (vsecattr.vsa_dfaclcnt && vsecattr.vsa_dfaclentp) {
158 			kmem_free(vsecattr.vsa_dfaclentp,
159 			    vsecattr.vsa_dfaclcnt * entry_size);
160 		}
161 		break;
162 	case GETACL:
163 		/*
164 		 * Minimum ACL size is three entries so might as well
165 		 * bail out here.
166 		 */
167 		if (nentries < 3)
168 			return (EINVAL);
169 		/*
170 		 * NULL output buffer is also a pretty easy bail out.
171 		 */
172 		if (aclbufp == NULL)
173 			return (EFAULT);
174 		vsecattr.vsa_mask = VSA_ACL | VSA_ACLCNT | VSA_DFACL |
175 		    VSA_DFACLCNT;
176 		if (error = VOP_GETSECATTR(vp, &vsecattr, 0, CRED(), NULL))
177 			return (error);
178 		/* Check user's buffer is big enough */
179 		numacls = vsecattr.vsa_aclcnt + vsecattr.vsa_dfaclcnt;
180 		aclbsize = vsecattr.vsa_aclcnt * sizeof (aclent_t);
181 		dfaclbsize = vsecattr.vsa_dfaclcnt * sizeof (aclent_t);
182 		if (numacls > nentries) {
183 			error = ENOSPC;
184 			goto errout;
185 		}
186 		/* Sort the acl & default acl lists */
187 		if (vsecattr.vsa_aclcnt > 1)
188 			ksort((caddr_t)vsecattr.vsa_aclentp,
189 			    vsecattr.vsa_aclcnt, sizeof (aclent_t), cmp2acls);
190 		if (vsecattr.vsa_dfaclcnt > 1)
191 			ksort((caddr_t)vsecattr.vsa_dfaclentp,
192 			    vsecattr.vsa_dfaclcnt, sizeof (aclent_t), cmp2acls);
193 		/* Copy out acl's */
194 		uaddrp = (caddr_t)aclbufp;
195 		if (aclbsize > 0) {	/* bug #1262490 */
196 			if (copyout(vsecattr.vsa_aclentp, uaddrp, aclbsize)) {
197 				error = EFAULT;
198 				goto errout;
199 			}
200 		}
201 		/* Copy out default acl's */
202 		if (dfaclbsize > 0) {
203 			uaddrp += aclbsize;
204 			if (copyout(vsecattr.vsa_dfaclentp,
205 			    uaddrp, dfaclbsize)) {
206 				error = EFAULT;
207 				goto errout;
208 			}
209 		}
210 		*rv = numacls;
211 		if (vsecattr.vsa_aclcnt) {
212 			kmem_free(vsecattr.vsa_aclentp,
213 			    vsecattr.vsa_aclcnt * sizeof (aclent_t));
214 		}
215 		if (vsecattr.vsa_dfaclcnt) {
216 			kmem_free(vsecattr.vsa_dfaclentp,
217 			    vsecattr.vsa_dfaclcnt * sizeof (aclent_t));
218 		}
219 		break;
220 
221 	case ACE_GETACL:
222 		if (aclbufp == NULL)
223 			return (EFAULT);
224 
225 		vsecattr.vsa_mask = VSA_ACE | VSA_ACECNT;
226 		if (error = VOP_GETSECATTR(vp, &vsecattr, 0, CRED(), NULL))
227 			return (error);
228 
229 		aclbsize = vsecattr.vsa_aclcnt * sizeof (ace_t);
230 		if (vsecattr.vsa_aclcnt > nentries) {
231 			error = ENOSPC;
232 			goto errout;
233 		}
234 
235 		if (aclbsize > 0) {
236 			if ((error = copyout(vsecattr.vsa_aclentp,
237 			    aclbufp, aclbsize)) != 0) {
238 				goto errout;
239 			}
240 		}
241 
242 		*rv = vsecattr.vsa_aclcnt;
243 		if (vsecattr.vsa_aclcnt) {
244 			kmem_free(vsecattr.vsa_aclentp, vsecattr.vsa_aclentsz);
245 		}
246 		break;
247 
248 	case SETACL:
249 		/*
250 		 * Minimum ACL size is three entries so might as well
251 		 * bail out here.  Also limit request size to prevent user
252 		 * from allocating too much kernel memory.  Maximum size
253 		 * is MAX_ACL_ENTRIES for the ACL part and MAX_ACL_ENTRIES
254 		 * for the default ACL part. (bug 4058667)
255 		 */
256 		if (nentries < 3 || nentries > (MAX_ACL_ENTRIES * 2))
257 			return (EINVAL);
258 		/*
259 		 * NULL output buffer is also an easy bail out.
260 		 */
261 		if (aclbufp == NULL)
262 			return (EFAULT);
263 		vsecattr.vsa_mask = VSA_ACL;
264 		aclbsize = nentries * sizeof (aclent_t);
265 		vsecattr.vsa_aclentp = kmem_alloc(aclbsize, KM_SLEEP);
266 		aaclp = vsecattr.vsa_aclentp;
267 		vsecattr.vsa_aclcnt = nentries;
268 		uaddrp = (caddr_t)aclbufp;
269 		if (copyin(uaddrp, vsecattr.vsa_aclentp, aclbsize)) {
270 			kmem_free(aaclp, aclbsize);
271 			return (EFAULT);
272 		}
273 		/* Sort the acl list */
274 		ksort((caddr_t)vsecattr.vsa_aclentp,
275 		    vsecattr.vsa_aclcnt, sizeof (aclent_t), cmp2acls);
276 
277 		/* Break into acl and default acl lists */
278 		for (numacls = 0, aclp = vsecattr.vsa_aclentp;
279 		    numacls < vsecattr.vsa_aclcnt;
280 		    aclp++, numacls++) {
281 			if (aclp->a_type & ACL_DEFAULT)
282 				break;
283 		}
284 
285 		/* Find where defaults start (if any) */
286 		if (numacls < vsecattr.vsa_aclcnt) {
287 			vsecattr.vsa_mask |= VSA_DFACL;
288 			vsecattr.vsa_dfaclcnt = nentries - numacls;
289 			vsecattr.vsa_dfaclentp = aclp;
290 			vsecattr.vsa_aclcnt = numacls;
291 		}
292 		/* Adjust if they're all defaults */
293 		if (vsecattr.vsa_aclcnt == 0) {
294 			vsecattr.vsa_mask &= ~VSA_ACL;
295 			vsecattr.vsa_aclentp = NULL;
296 		}
297 		/* Only directories can have defaults */
298 		if (vsecattr.vsa_dfaclcnt && vp->v_type != VDIR) {
299 			kmem_free(aaclp, aclbsize);
300 			return (ENOTDIR);
301 		}
302 		(void) VOP_RWLOCK(vp, V_WRITELOCK_TRUE, NULL);
303 		if (error = VOP_SETSECATTR(vp, &vsecattr, 0, CRED(), NULL)) {
304 			kmem_free(aaclp, aclbsize);
305 			VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
306 			return (error);
307 		}
308 
309 		/*
310 		 * Should return 0 upon success according to the man page
311 		 * and SVR4 semantics. (Bug #1214399: SETACL returns wrong rc)
312 		 */
313 		*rv = 0;
314 		kmem_free(aaclp, aclbsize);
315 		VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
316 		break;
317 
318 	case ACE_SETACL:
319 		if (nentries < 1 || nentries > MAX_ACL_ENTRIES)
320 			return (EINVAL);
321 
322 		if (aclbufp == NULL)
323 			return (EFAULT);
324 
325 		vsecattr.vsa_mask = VSA_ACE;
326 		aclbsize = nentries * sizeof (ace_t);
327 		vsecattr.vsa_aclentp = kmem_alloc(aclbsize, KM_SLEEP);
328 		aaclp = vsecattr.vsa_aclentp;
329 		vsecattr.vsa_aclcnt = nentries;
330 		vsecattr.vsa_aclentsz = aclbsize;
331 		uaddrp = (caddr_t)aclbufp;
332 		if (copyin(uaddrp, vsecattr.vsa_aclentp, aclbsize)) {
333 			kmem_free(aaclp, aclbsize);
334 			return (EFAULT);
335 		}
336 		(void) VOP_RWLOCK(vp, V_WRITELOCK_TRUE, NULL);
337 		if (error = VOP_SETSECATTR(vp, &vsecattr, 0, CRED(), NULL)) {
338 			kmem_free(aaclp, aclbsize);
339 			VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
340 			return (error);
341 		}
342 		*rv = 0;
343 		kmem_free(aaclp, aclbsize);
344 		VOP_RWUNLOCK(vp, V_WRITELOCK_TRUE, NULL);
345 		break;
346 
347 	default:
348 		return (EINVAL);
349 	}
350 
351 	return (0);
352 
353 errout:
354 	if (aclbsize && vsecattr.vsa_aclentp)
355 		kmem_free(vsecattr.vsa_aclentp, aclbsize);
356 	if (dfaclbsize && vsecattr.vsa_dfaclentp)
357 		kmem_free(vsecattr.vsa_dfaclentp, dfaclbsize);
358 	return (error);
359 }
360