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 1.9 2005/03/29 00:35:55 drhodus 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 static MALLOC_DEFINE(M_ACL, "acl", "access control list"); 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 KKASSERT(td->td_proc); 80 ucred = td->td_proc->p_ucred; 81 82 VOP_LEASE(vp, td, ucred, LEASE_WRITE); 83 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 84 error = VOP_SETACL(vp, type, &inkernacl, ucred, td); 85 VOP_UNLOCK(vp, 0, td); 86 return(error); 87 } 88 89 /* 90 * Given a vnode, get its ACL. 91 */ 92 static int 93 vacl_get_acl(struct vnode *vp, acl_type_t type, struct acl *aclp) 94 { 95 struct thread *td = curthread; 96 struct acl inkernelacl; 97 struct ucred *ucred; 98 int error; 99 100 KKASSERT(td->td_proc); 101 ucred = td->td_proc->p_ucred; 102 error = VOP_GETACL(vp, type, &inkernelacl, ucred, td); 103 if (error == 0) 104 error = copyout(&inkernelacl, aclp, sizeof(struct acl)); 105 return (error); 106 } 107 108 /* 109 * Given a vnode, delete its ACL. 110 */ 111 static int 112 vacl_delete(struct vnode *vp, acl_type_t type) 113 { 114 struct thread *td = curthread; 115 struct ucred *ucred; 116 int error; 117 118 KKASSERT(td->td_proc); 119 ucred = td->td_proc->p_ucred; 120 VOP_LEASE(vp, td, ucred, LEASE_WRITE); 121 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 122 error = VOP_SETACL(vp, ACL_TYPE_DEFAULT, 0, ucred, td); 123 VOP_UNLOCK(vp, 0, td); 124 return (error); 125 } 126 127 /* 128 * Given a vnode, check whether an ACL is appropriate for it 129 */ 130 static int 131 vacl_aclcheck(struct vnode *vp, acl_type_t type, struct acl *aclp) 132 { 133 struct thread *td = curthread; 134 struct ucred *ucred; 135 struct acl inkernelacl; 136 int error; 137 138 KKASSERT(td->td_proc); 139 ucred = td->td_proc->p_ucred; 140 error = copyin(aclp, &inkernelacl, sizeof(struct acl)); 141 if (error) 142 return(error); 143 error = VOP_ACLCHECK(vp, type, &inkernelacl, ucred, td); 144 return (error); 145 } 146 147 /* 148 * syscalls -- convert the path/fd to a vnode, and call vacl_whatever. 149 * Don't need to lock, as the vacl_ code will get/release any locks 150 * required. 151 */ 152 153 /* 154 * Given a file path, get an ACL for it 155 */ 156 int 157 __acl_get_file(struct __acl_get_file_args *uap) 158 { 159 struct nlookupdata nd; 160 struct vnode *vp; 161 int error; 162 163 vp = NULL; 164 error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW); 165 if (error == 0) 166 error = nlookup(&nd); 167 if (error == 0) 168 error = cache_vref(nd.nl_ncp, nd.nl_cred, &vp); 169 nlookup_done(&nd); 170 if (error == 0) { 171 error = vacl_get_acl(vp, uap->type, uap->aclp); 172 vrele(vp); 173 } 174 return (error); 175 } 176 177 /* 178 * Given a file path, set an ACL for it 179 */ 180 int 181 __acl_set_file(struct __acl_set_file_args *uap) 182 { 183 struct nlookupdata nd; 184 struct vnode *vp; 185 int error; 186 187 vp = NULL; 188 error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW); 189 if (error == 0) 190 error = nlookup(&nd); 191 if (error == 0) 192 error = cache_vref(nd.nl_ncp, nd.nl_cred, &vp); 193 nlookup_done(&nd); 194 if (error == 0) { 195 error = vacl_set_acl(vp, uap->type, uap->aclp); 196 vrele(vp); 197 } 198 return (error); 199 } 200 201 /* 202 * Given a file descriptor, get an ACL for it 203 */ 204 int 205 __acl_get_fd(struct __acl_get_fd_args *uap) 206 { 207 struct thread *td = curthread; 208 struct file *fp; 209 int error; 210 211 KKASSERT(td->td_proc); 212 error = getvnode(td->td_proc->p_fd, uap->filedes, &fp); 213 if (error) 214 return(error); 215 return vacl_get_acl((struct vnode *)fp->f_data, uap->type, 216 uap->aclp); 217 } 218 219 /* 220 * Given a file descriptor, set an ACL for it 221 */ 222 int 223 __acl_set_fd(struct __acl_set_fd_args *uap) 224 { 225 struct thread *td = curthread; 226 struct file *fp; 227 int error; 228 229 KKASSERT(td->td_proc); 230 error = getvnode(td->td_proc->p_fd, uap->filedes, &fp); 231 if (error) 232 return(error); 233 return vacl_set_acl((struct vnode *)fp->f_data, uap->type, 234 uap->aclp); 235 } 236 237 /* 238 * Given a file path, delete an ACL from it. 239 */ 240 int 241 __acl_delete_file(struct __acl_delete_file_args *uap) 242 { 243 struct nlookupdata nd; 244 struct vnode *vp; 245 int error; 246 247 vp = NULL; 248 error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW); 249 if (error == 0) 250 error = nlookup(&nd); 251 if (error == 0) 252 error = cache_vref(nd.nl_ncp, nd.nl_cred, &vp); 253 nlookup_done(&nd); 254 255 if (error == 0) { 256 error = vacl_delete(vp, uap->type); 257 vrele(vp); 258 } 259 return (error); 260 } 261 262 /* 263 * Given a file path, delete an ACL from it. 264 */ 265 int 266 __acl_delete_fd(struct __acl_delete_fd_args *uap) 267 { 268 struct thread *td = curthread; 269 struct file *fp; 270 int error; 271 272 KKASSERT(td->td_proc); 273 error = getvnode(td->td_proc->p_fd, uap->filedes, &fp); 274 if (error) 275 return(error); 276 error = vacl_delete((struct vnode *)fp->f_data, uap->type); 277 return (error); 278 } 279 280 /* 281 * Given a file path, check an ACL for it 282 */ 283 int 284 __acl_aclcheck_file(struct __acl_aclcheck_file_args *uap) 285 { 286 struct nlookupdata nd; 287 struct vnode *vp; 288 int error; 289 290 vp = NULL; 291 error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW); 292 if (error == 0) 293 error = nlookup(&nd); 294 if (error == 0) 295 error = cache_vref(nd.nl_ncp, nd.nl_cred, &vp); 296 nlookup_done(&nd); 297 298 if (error == 0) { 299 error = vacl_aclcheck(vp, uap->type, uap->aclp); 300 vrele(vp); 301 } 302 return (error); 303 } 304 305 /* 306 * Given a file descriptor, check an ACL for it 307 */ 308 int 309 __acl_aclcheck_fd(struct __acl_aclcheck_fd_args *uap) 310 { 311 struct thread *td = curthread; 312 struct file *fp; 313 int error; 314 315 KKASSERT(td->td_proc); 316 error = getvnode(td->td_proc->p_fd, uap->filedes, &fp); 317 if (error) 318 return(error); 319 return vacl_aclcheck((struct vnode *)fp->f_data, uap->type, 320 uap->aclp); 321 } 322