FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_acl.c
1 /*-
2 * Copyright (c) 1999, 2000 Robert N. M. Watson
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: src/sys/kern/kern_acl.c,v 1.2.2.1 2000/07/28 18:48:16 rwatson Exp $
27 * $DragonFly: src/sys/kern/kern_acl.c,v 1.17 2007/02/19 00:51:54 swildner Exp $
28 */
29
30 /*
31 * Generic routines to support file system ACLs, at a syntactic level
32 * Semantics are the responsibility of the underlying file system
33 */
34
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/sysproto.h>
38 #include <sys/kernel.h>
39 #include <sys/malloc.h>
40 #include <sys/vnode.h>
41 #include <sys/lock.h>
42 #include <sys/proc.h>
43 #include <sys/nlookup.h>
44 #include <sys/file.h>
45 #include <sys/sysent.h>
46 #include <sys/errno.h>
47 #include <sys/stat.h>
48 #include <sys/acl.h>
49
50 #include <sys/mplock2.h>
51
52 static int vacl_set_acl(struct vnode *vp, acl_type_t type, struct acl *aclp);
53 static int vacl_get_acl(struct vnode *vp, acl_type_t type, struct acl *aclp);
54 static int vacl_aclcheck(struct vnode *vp, acl_type_t type, struct acl *aclp);
55
56 /*
57 * These calls wrap the real vnode operations, and are called by the
58 * syscall code once the syscall has converted the path or file
59 * descriptor to a vnode (unlocked). The aclp pointer is assumed
60 * still to point to userland, so this should not be consumed within
61 * the kernel except by syscall code. Other code should directly
62 * invoke VOP_{SET,GET}ACL.
63 */
64
65 /*
66 * Given a vnode, set its ACL.
67 */
68 static int
69 vacl_set_acl(struct vnode *vp, acl_type_t type, struct acl *aclp)
70 {
71 struct thread *td = curthread;
72 struct acl inkernacl;
73 struct ucred *ucred;
74 int error;
75
76 error = copyin(aclp, &inkernacl, sizeof(struct acl));
77 if (error)
78 return(error);
79 ucred = td->td_ucred;
80
81 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
82 error = VOP_SETACL(vp, type, &inkernacl, ucred);
83 vn_unlock(vp);
84 return(error);
85 }
86
87 /*
88 * Given a vnode, get its ACL.
89 */
90 static int
91 vacl_get_acl(struct vnode *vp, acl_type_t type, struct acl *aclp)
92 {
93 struct thread *td = curthread;
94 struct acl inkernelacl;
95 struct ucred *ucred;
96 int error;
97
98 ucred = td->td_ucred;
99 error = VOP_GETACL(vp, type, &inkernelacl, ucred);
100 if (error == 0)
101 error = copyout(&inkernelacl, aclp, sizeof(struct acl));
102 return (error);
103 }
104
105 /*
106 * Given a vnode, delete its ACL.
107 */
108 static int
109 vacl_delete(struct vnode *vp, acl_type_t type)
110 {
111 struct thread *td = curthread;
112 struct ucred *ucred;
113 int error;
114
115 ucred = td->td_ucred;
116 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
117 error = VOP_SETACL(vp, ACL_TYPE_DEFAULT, 0, ucred);
118 vn_unlock(vp);
119 return (error);
120 }
121
122 /*
123 * Given a vnode, check whether an ACL is appropriate for it
124 */
125 static int
126 vacl_aclcheck(struct vnode *vp, acl_type_t type, struct acl *aclp)
127 {
128 struct thread *td = curthread;
129 struct ucred *ucred;
130 struct acl inkernelacl;
131 int error;
132
133 ucred = td->td_ucred;
134 error = copyin(aclp, &inkernelacl, sizeof(struct acl));
135 if (error)
136 return(error);
137 error = VOP_ACLCHECK(vp, type, &inkernelacl, ucred);
138 return (error);
139 }
140
141 /*
142 * syscalls -- convert the path/fd to a vnode, and call vacl_whatever.
143 * Don't need to lock, as the vacl_ code will get/release any locks
144 * required.
145 */
146
147 /*
148 * Given a file path, get an ACL for it
149 */
150 int
151 sys___acl_get_file(struct __acl_get_file_args *uap)
152 {
153 struct nlookupdata nd;
154 struct vnode *vp;
155 int error;
156
157 vp = NULL;
158 error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
159 if (error == 0)
160 error = nlookup(&nd);
161 if (error == 0)
162 error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp);
163 nlookup_done(&nd);
164 if (error == 0) {
165 error = vacl_get_acl(vp, uap->type, uap->aclp);
166 vrele(vp);
167 }
168 return (error);
169 }
170
171 /*
172 * Given a file path, set an ACL for it
173 */
174 int
175 sys___acl_set_file(struct __acl_set_file_args *uap)
176 {
177 struct nlookupdata nd;
178 struct vnode *vp;
179 int error;
180
181 vp = NULL;
182 error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
183 if (error == 0)
184 error = nlookup(&nd);
185 if (error == 0)
186 error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp);
187 nlookup_done(&nd);
188 if (error == 0) {
189 error = vacl_set_acl(vp, uap->type, uap->aclp);
190 vrele(vp);
191 }
192 return (error);
193 }
194
195 /*
196 * Given a file descriptor, get an ACL for it
197 */
198 int
199 sys___acl_get_fd(struct __acl_get_fd_args *uap)
200 {
201 struct thread *td = curthread;
202 struct file *fp;
203 int error;
204
205 KKASSERT(td->td_proc);
206 if ((error = holdvnode(td->td_proc->p_fd, uap->filedes, &fp)) != 0)
207 return(error);
208 error = vacl_get_acl((struct vnode *)fp->f_data, uap->type, uap->aclp);
209 fdrop(fp);
210
211 return (error);
212 }
213
214 /*
215 * Given a file descriptor, set an ACL for it
216 */
217 int
218 sys___acl_set_fd(struct __acl_set_fd_args *uap)
219 {
220 struct thread *td = curthread;
221 struct file *fp;
222 int error;
223
224 KKASSERT(td->td_proc);
225 if ((error = holdvnode(td->td_proc->p_fd, uap->filedes, &fp)) != 0)
226 return(error);
227 error = vacl_set_acl((struct vnode *)fp->f_data, uap->type, uap->aclp);
228 fdrop(fp);
229 return (error);
230 }
231
232 /*
233 * Given a file path, delete an ACL from it.
234 */
235 int
236 sys___acl_delete_file(struct __acl_delete_file_args *uap)
237 {
238 struct nlookupdata nd;
239 struct vnode *vp;
240 int error;
241
242 vp = NULL;
243 error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
244 if (error == 0)
245 error = nlookup(&nd);
246 if (error == 0)
247 error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp);
248 nlookup_done(&nd);
249
250 if (error == 0) {
251 error = vacl_delete(vp, uap->type);
252 vrele(vp);
253 }
254 return (error);
255 }
256
257 /*
258 * Given a file path, delete an ACL from it.
259 */
260 int
261 sys___acl_delete_fd(struct __acl_delete_fd_args *uap)
262 {
263 struct thread *td = curthread;
264 struct file *fp;
265 int error;
266
267 KKASSERT(td->td_proc);
268 if ((error = holdvnode(td->td_proc->p_fd, uap->filedes, &fp)) != 0)
269 return(error);
270 error = vacl_delete((struct vnode *)fp->f_data, uap->type);
271 fdrop(fp);
272 return (error);
273 }
274
275 /*
276 * Given a file path, check an ACL for it
277 */
278 int
279 sys___acl_aclcheck_file(struct __acl_aclcheck_file_args *uap)
280 {
281 struct nlookupdata nd;
282 struct vnode *vp;
283 int error;
284
285 vp = NULL;
286 error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
287 if (error == 0)
288 error = nlookup(&nd);
289 if (error == 0)
290 error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp);
291 nlookup_done(&nd);
292
293 if (error == 0) {
294 error = vacl_aclcheck(vp, uap->type, uap->aclp);
295 vrele(vp);
296 }
297 return (error);
298 }
299
300 /*
301 * Given a file descriptor, check an ACL for it
302 */
303 int
304 sys___acl_aclcheck_fd(struct __acl_aclcheck_fd_args *uap)
305 {
306 struct thread *td = curthread;
307 struct file *fp;
308 int error;
309
310 KKASSERT(td->td_proc);
311 if ((error = holdvnode(td->td_proc->p_fd, uap->filedes, &fp)) != 0)
312 return(error);
313 error = vacl_aclcheck((struct vnode *)fp->f_data, uap->type, uap->aclp);
314 fdrop(fp);
315 return (error);
316 }
317
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