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 static int vacl_set_acl(struct vnode *vp, acl_type_t type, struct acl *aclp); 51 static int vacl_get_acl(struct vnode *vp, acl_type_t type, struct acl *aclp); 52 static int vacl_aclcheck(struct vnode *vp, acl_type_t type, struct acl *aclp); 53 54 /* 55 * These calls wrap the real vnode operations, and are called by the 56 * syscall code once the syscall has converted the path or file 57 * descriptor to a vnode (unlocked). The aclp pointer is assumed 58 * still to point to userland, so this should not be consumed within 59 * the kernel except by syscall code. Other code should directly 60 * invoke VOP_{SET,GET}ACL. 61 */ 62 63 /* 64 * Given a vnode, set its ACL. 65 */ 66 static int 67 vacl_set_acl(struct vnode *vp, acl_type_t type, struct acl *aclp) 68 { 69 struct thread *td = curthread; 70 struct acl inkernacl; 71 struct ucred *ucred; 72 int error; 73 74 error = copyin(aclp, &inkernacl, sizeof(struct acl)); 75 if (error) 76 return(error); 77 KKASSERT(td->td_proc); 78 ucred = td->td_proc->p_ucred; 79 80 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 81 error = VOP_SETACL(vp, type, &inkernacl, ucred); 82 vn_unlock(vp); 83 return(error); 84 } 85 86 /* 87 * Given a vnode, get its ACL. 88 */ 89 static int 90 vacl_get_acl(struct vnode *vp, acl_type_t type, struct acl *aclp) 91 { 92 struct thread *td = curthread; 93 struct acl inkernelacl; 94 struct ucred *ucred; 95 int error; 96 97 KKASSERT(td->td_proc); 98 ucred = td->td_proc->p_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 KKASSERT(td->td_proc); 116 ucred = td->td_proc->p_ucred; 117 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 118 error = VOP_SETACL(vp, ACL_TYPE_DEFAULT, 0, ucred); 119 vn_unlock(vp); 120 return (error); 121 } 122 123 /* 124 * Given a vnode, check whether an ACL is appropriate for it 125 */ 126 static int 127 vacl_aclcheck(struct vnode *vp, acl_type_t type, struct acl *aclp) 128 { 129 struct thread *td = curthread; 130 struct ucred *ucred; 131 struct acl inkernelacl; 132 int error; 133 134 KKASSERT(td->td_proc); 135 ucred = td->td_proc->p_ucred; 136 error = copyin(aclp, &inkernelacl, sizeof(struct acl)); 137 if (error) 138 return(error); 139 error = VOP_ACLCHECK(vp, type, &inkernelacl, ucred); 140 return (error); 141 } 142 143 /* 144 * syscalls -- convert the path/fd to a vnode, and call vacl_whatever. 145 * Don't need to lock, as the vacl_ code will get/release any locks 146 * required. 147 */ 148 149 /* 150 * Given a file path, get an ACL for it 151 */ 152 int 153 sys___acl_get_file(struct __acl_get_file_args *uap) 154 { 155 struct nlookupdata nd; 156 struct vnode *vp; 157 int error; 158 159 vp = NULL; 160 error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW); 161 if (error == 0) 162 error = nlookup(&nd); 163 if (error == 0) 164 error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp); 165 nlookup_done(&nd); 166 if (error == 0) { 167 error = vacl_get_acl(vp, uap->type, uap->aclp); 168 vrele(vp); 169 } 170 return (error); 171 } 172 173 /* 174 * Given a file path, set an ACL for it 175 */ 176 int 177 sys___acl_set_file(struct __acl_set_file_args *uap) 178 { 179 struct nlookupdata nd; 180 struct vnode *vp; 181 int error; 182 183 vp = NULL; 184 error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW); 185 if (error == 0) 186 error = nlookup(&nd); 187 if (error == 0) 188 error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp); 189 nlookup_done(&nd); 190 if (error == 0) { 191 error = vacl_set_acl(vp, uap->type, uap->aclp); 192 vrele(vp); 193 } 194 return (error); 195 } 196 197 /* 198 * Given a file descriptor, get an ACL for it 199 */ 200 int 201 sys___acl_get_fd(struct __acl_get_fd_args *uap) 202 { 203 struct thread *td = curthread; 204 struct file *fp; 205 int error; 206 207 KKASSERT(td->td_proc); 208 if ((error = holdvnode(td->td_proc->p_fd, uap->filedes, &fp)) != 0) 209 return(error); 210 error = vacl_get_acl((struct vnode *)fp->f_data, uap->type, uap->aclp); 211 fdrop(fp); 212 return (error); 213 } 214 215 /* 216 * Given a file descriptor, set an ACL for it 217 */ 218 int 219 sys___acl_set_fd(struct __acl_set_fd_args *uap) 220 { 221 struct thread *td = curthread; 222 struct file *fp; 223 int error; 224 225 KKASSERT(td->td_proc); 226 if ((error = holdvnode(td->td_proc->p_fd, uap->filedes, &fp)) != 0) 227 return(error); 228 error = vacl_set_acl((struct vnode *)fp->f_data, uap->type, uap->aclp); 229 fdrop(fp); 230 return (error); 231 } 232 233 /* 234 * Given a file path, delete an ACL from it. 235 */ 236 int 237 sys___acl_delete_file(struct __acl_delete_file_args *uap) 238 { 239 struct nlookupdata nd; 240 struct vnode *vp; 241 int error; 242 243 vp = NULL; 244 error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW); 245 if (error == 0) 246 error = nlookup(&nd); 247 if (error == 0) 248 error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp); 249 nlookup_done(&nd); 250 251 if (error == 0) { 252 error = vacl_delete(vp, uap->type); 253 vrele(vp); 254 } 255 return (error); 256 } 257 258 /* 259 * Given a file path, delete an ACL from it. 260 */ 261 int 262 sys___acl_delete_fd(struct __acl_delete_fd_args *uap) 263 { 264 struct thread *td = curthread; 265 struct file *fp; 266 int error; 267 268 KKASSERT(td->td_proc); 269 if ((error = holdvnode(td->td_proc->p_fd, uap->filedes, &fp)) != 0) 270 return(error); 271 error = vacl_delete((struct vnode *)fp->f_data, uap->type); 272 fdrop(fp); 273 return (error); 274 } 275 276 /* 277 * Given a file path, check an ACL for it 278 */ 279 int 280 sys___acl_aclcheck_file(struct __acl_aclcheck_file_args *uap) 281 { 282 struct nlookupdata nd; 283 struct vnode *vp; 284 int error; 285 286 vp = NULL; 287 error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW); 288 if (error == 0) 289 error = nlookup(&nd); 290 if (error == 0) 291 error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp); 292 nlookup_done(&nd); 293 294 if (error == 0) { 295 error = vacl_aclcheck(vp, uap->type, uap->aclp); 296 vrele(vp); 297 } 298 return (error); 299 } 300 301 /* 302 * Given a file descriptor, check an ACL for it 303 */ 304 int 305 sys___acl_aclcheck_fd(struct __acl_aclcheck_fd_args *uap) 306 { 307 struct thread *td = curthread; 308 struct file *fp; 309 int error; 310 311 KKASSERT(td->td_proc); 312 if ((error = holdvnode(td->td_proc->p_fd, uap->filedes, &fp)) != 0) 313 return(error); 314 error = vacl_aclcheck((struct vnode *)fp->f_data, uap->type, uap->aclp); 315 fdrop(fp); 316 return (error); 317 } 318 319