xref: /titanic_52/usr/src/uts/common/syscall/acl.c (revision 84ab085a13f931bc78e7415e7ce921dbaa14fcb3)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 /*
31  * Portions of this source code were derived from Berkeley 4.3 BSD
32  * under license from the Regents of the University of California.
33  */
34 
35 #pragma ident	"%Z%%M%	%I%	%E% SMI"
36 
37 #include <sys/param.h>
38 #include <sys/isa_defs.h>
39 #include <sys/types.h>
40 #include <sys/sysmacros.h>
41 #include <sys/cred.h>
42 #include <sys/systm.h>
43 #include <sys/errno.h>
44 #include <sys/fcntl.h>
45 #include <sys/pathname.h>
46 #include <sys/vfs.h>
47 #include <sys/vnode.h>
48 #include <sys/file.h>
49 #include <sys/mode.h>
50 #include <sys/uio.h>
51 #include <sys/kmem.h>
52 #include <sys/filio.h>
53 #include <sys/acl.h>
54 #include <sys/cmn_err.h>
55 
56 #include <sys/unistd.h>
57 #include <sys/debug.h>
58 
59 static int cacl(int cmd, int nentries, void *aclbufp,
60     vnode_t *vp, int *rv);
61 
62 /*
63  * Get/Set ACL of a file.
64  */
65 int
66 acl(const char *fname, int cmd, int nentries, void *aclbufp)
67 {
68 	struct vnode *vp;
69 	int error;
70 	int rv = 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)
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)
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 #ifdef C2_AUDIT
106 	if (fp->f_flag & FREVOKED) {
107 		releasef(fdes);
108 		return (set_errno(EBADF));
109 	}
110 #endif /* C2_AUDIT */
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 
135 	ASSERT(vp);
136 
137 	bzero(&vsecattr, sizeof (vsecattr_t));
138 
139 	switch (cmd) {
140 
141 	case ACE_GETACLCNT:
142 	case GETACLCNT:
143 		if (cmd == GETACLCNT)
144 			vsecattr.vsa_mask = VSA_ACLCNT | VSA_DFACLCNT;
145 		else
146 			vsecattr.vsa_mask = VSA_ACECNT;
147 		if (error = VOP_GETSECATTR(vp, &vsecattr, 0, CRED()))
148 			return (error);
149 		*rv = vsecattr.vsa_aclcnt + vsecattr.vsa_dfaclcnt;
150 		if (vsecattr.vsa_aclcnt && vsecattr.vsa_aclentp) {
151 			kmem_free(vsecattr.vsa_aclentp,
152 			    vsecattr.vsa_aclcnt * sizeof (aclent_t));
153 		}
154 		if (vsecattr.vsa_dfaclcnt && vsecattr.vsa_dfaclentp) {
155 			kmem_free(vsecattr.vsa_dfaclentp,
156 			    vsecattr.vsa_dfaclcnt * sizeof (aclent_t));
157 		}
158 		break;
159 	case GETACL:
160 		/*
161 		 * Minimum ACL size is three entries so might as well
162 		 * bail out here.
163 		 */
164 		if (nentries < 3)
165 			return (EINVAL);
166 		/*
167 		 * NULL output buffer is also a pretty easy bail out.
168 		 */
169 		if (aclbufp == NULL)
170 			return (EFAULT);
171 		vsecattr.vsa_mask = VSA_ACL | VSA_ACLCNT | VSA_DFACL |
172 		    VSA_DFACLCNT;
173 		if (error = VOP_GETSECATTR(vp, &vsecattr, 0, CRED()))
174 			return (error);
175 		/* Check user's buffer is big enough */
176 		numacls = vsecattr.vsa_aclcnt + vsecattr.vsa_dfaclcnt;
177 		aclbsize = vsecattr.vsa_aclcnt * sizeof (aclent_t);
178 		dfaclbsize = vsecattr.vsa_dfaclcnt * sizeof (aclent_t);
179 		if (numacls > nentries) {
180 			error = ENOSPC;
181 			goto errout;
182 		}
183 		/* Sort the acl & default acl lists */
184 		if (vsecattr.vsa_aclcnt > 1)
185 			ksort((caddr_t)vsecattr.vsa_aclentp,
186 			vsecattr.vsa_aclcnt, sizeof (aclent_t), cmp2acls);
187 		if (vsecattr.vsa_dfaclcnt > 1)
188 			ksort((caddr_t)vsecattr.vsa_dfaclentp,
189 			vsecattr.vsa_dfaclcnt, sizeof (aclent_t), cmp2acls);
190 		/* Copy out acl's */
191 		uaddrp = (caddr_t)aclbufp;
192 		if (aclbsize > 0) {	/* bug #1262490 */
193 			if (copyout(vsecattr.vsa_aclentp, uaddrp, aclbsize)) {
194 				error = EFAULT;
195 				goto errout;
196 			}
197 		}
198 		/* Copy out default acl's */
199 		if (dfaclbsize > 0) {
200 			uaddrp += aclbsize;
201 			if (copyout(vsecattr.vsa_dfaclentp,
202 			    uaddrp, dfaclbsize)) {
203 				error = EFAULT;
204 				goto errout;
205 			}
206 		}
207 		*rv = numacls;
208 		if (vsecattr.vsa_aclcnt) {
209 			kmem_free(vsecattr.vsa_aclentp,
210 			    vsecattr.vsa_aclcnt * sizeof (aclent_t));
211 		}
212 		if (vsecattr.vsa_dfaclcnt) {
213 			kmem_free(vsecattr.vsa_dfaclentp,
214 			    vsecattr.vsa_dfaclcnt * sizeof (aclent_t));
215 		}
216 		break;
217 
218 	case ACE_GETACL:
219 		if (nentries < 3)
220 			return (EINVAL);
221 
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()))
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,
245 			    vsecattr.vsa_aclcnt * sizeof (ace_t));
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())) {
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 < 3 || nentries > (MAX_ACL_ENTRIES * 2))
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 		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())) {
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 
361 
362 /*
363  * Generic shellsort, from K&R (1st ed, p 58.), somewhat modified.
364  * v = Ptr to array/vector of objs
365  * n = # objs in the array
366  * s = size of each obj (must be multiples of a word size)
367  * f = ptr to function to compare two objs
368  *	returns (-1 = less than, 0 = equal, 1 = greater than
369  */
370 void
371 ksort(caddr_t v, int n, int s, int (*f)())
372 {
373 	int g, i, j, ii;
374 	unsigned int *p1, *p2;
375 	unsigned int tmp;
376 
377 	/* No work to do */
378 	if (v == NULL || n <= 1)
379 		return;
380 
381 	/* Sanity check on arguments */
382 	ASSERT(((uintptr_t)v & 0x3) == 0 && (s & 0x3) == 0);
383 	ASSERT(s > 0);
384 	for (g = n / 2; g > 0; g /= 2) {
385 		for (i = g; i < n; i++) {
386 			for (j = i - g; j >= 0 &&
387 				(*f)(v + j * s, v + (j + g) * s) == 1;
388 					j -= g) {
389 				p1 = (unsigned *)(v + j * s);
390 				p2 = (unsigned *)(v + (j + g) * s);
391 				for (ii = 0; ii < s / 4; ii++) {
392 					tmp = *p1;
393 					*p1++ = *p2;
394 					*p2++ = tmp;
395 				}
396 			}
397 		}
398 	}
399 }
400 
401 /*
402  * Compare two acls, all fields.  Returns:
403  * -1 (less than)
404  *  0 (equal)
405  * +1 (greater than)
406  */
407 int
408 cmp2acls(void *a, void *b)
409 {
410 	aclent_t *x = (aclent_t *)a;
411 	aclent_t *y = (aclent_t *)b;
412 
413 	/* Compare types */
414 	if (x->a_type < y->a_type)
415 		return (-1);
416 	if (x->a_type > y->a_type)
417 		return (1);
418 	/* Equal types; compare id's */
419 	if (x->a_id < y->a_id)
420 		return (-1);
421 	if (x->a_id > y->a_id)
422 		return (1);
423 	/* Equal ids; compare perms */
424 	if (x->a_perm < y->a_perm)
425 		return (-1);
426 	if (x->a_perm > y->a_perm)
427 		return (1);
428 	/* Totally equal */
429 	return (0);
430 }
431