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 1.14 2006/06/05 07:26:10 dillon 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 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 83 error = VOP_SETACL(vp, type, &inkernacl, ucred); 84 VOP_UNLOCK(vp, 0); 85 return(error); 86 } 87 88 /* 89 * Given a vnode, get its ACL. 90 */ 91 static int 92 vacl_get_acl(struct vnode *vp, acl_type_t type, struct acl *aclp) 93 { 94 struct thread *td = curthread; 95 struct acl inkernelacl; 96 struct ucred *ucred; 97 int error; 98 99 KKASSERT(td->td_proc); 100 ucred = td->td_proc->p_ucred; 101 error = VOP_GETACL(vp, type, &inkernelacl, ucred); 102 if (error == 0) 103 error = copyout(&inkernelacl, aclp, sizeof(struct acl)); 104 return (error); 105 } 106 107 /* 108 * Given a vnode, delete its ACL. 109 */ 110 static int 111 vacl_delete(struct vnode *vp, acl_type_t type) 112 { 113 struct thread *td = curthread; 114 struct ucred *ucred; 115 int error; 116 117 KKASSERT(td->td_proc); 118 ucred = td->td_proc->p_ucred; 119 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 120 error = VOP_SETACL(vp, ACL_TYPE_DEFAULT, 0, ucred); 121 VOP_UNLOCK(vp, 0); 122 return (error); 123 } 124 125 /* 126 * Given a vnode, check whether an ACL is appropriate for it 127 */ 128 static int 129 vacl_aclcheck(struct vnode *vp, acl_type_t type, struct acl *aclp) 130 { 131 struct thread *td = curthread; 132 struct ucred *ucred; 133 struct acl inkernelacl; 134 int error; 135 136 KKASSERT(td->td_proc); 137 ucred = td->td_proc->p_ucred; 138 error = copyin(aclp, &inkernelacl, sizeof(struct acl)); 139 if (error) 140 return(error); 141 error = VOP_ACLCHECK(vp, type, &inkernelacl, ucred); 142 return (error); 143 } 144 145 /* 146 * syscalls -- convert the path/fd to a vnode, and call vacl_whatever. 147 * Don't need to lock, as the vacl_ code will get/release any locks 148 * required. 149 */ 150 151 /* 152 * Given a file path, get an ACL for it 153 */ 154 int 155 sys___acl_get_file(struct __acl_get_file_args *uap) 156 { 157 struct nlookupdata nd; 158 struct vnode *vp; 159 int error; 160 161 vp = NULL; 162 error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW); 163 if (error == 0) 164 error = nlookup(&nd); 165 if (error == 0) 166 error = cache_vref(nd.nl_ncp, nd.nl_cred, &vp); 167 nlookup_done(&nd); 168 if (error == 0) { 169 error = vacl_get_acl(vp, uap->type, uap->aclp); 170 vrele(vp); 171 } 172 return (error); 173 } 174 175 /* 176 * Given a file path, set an ACL for it 177 */ 178 int 179 sys___acl_set_file(struct __acl_set_file_args *uap) 180 { 181 struct nlookupdata nd; 182 struct vnode *vp; 183 int error; 184 185 vp = NULL; 186 error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW); 187 if (error == 0) 188 error = nlookup(&nd); 189 if (error == 0) 190 error = cache_vref(nd.nl_ncp, nd.nl_cred, &vp); 191 nlookup_done(&nd); 192 if (error == 0) { 193 error = vacl_set_acl(vp, uap->type, uap->aclp); 194 vrele(vp); 195 } 196 return (error); 197 } 198 199 /* 200 * Given a file descriptor, get an ACL for it 201 */ 202 int 203 sys___acl_get_fd(struct __acl_get_fd_args *uap) 204 { 205 struct thread *td = curthread; 206 struct file *fp; 207 int error; 208 209 KKASSERT(td->td_proc); 210 if ((error = holdvnode(td->td_proc->p_fd, uap->filedes, &fp)) != 0) 211 return(error); 212 error = vacl_get_acl((struct vnode *)fp->f_data, uap->type, uap->aclp); 213 fdrop(fp); 214 return (error); 215 } 216 217 /* 218 * Given a file descriptor, set an ACL for it 219 */ 220 int 221 sys___acl_set_fd(struct __acl_set_fd_args *uap) 222 { 223 struct thread *td = curthread; 224 struct file *fp; 225 int error; 226 227 KKASSERT(td->td_proc); 228 if ((error = holdvnode(td->td_proc->p_fd, uap->filedes, &fp)) != 0) 229 return(error); 230 error = vacl_set_acl((struct vnode *)fp->f_data, uap->type, uap->aclp); 231 fdrop(fp); 232 return (error); 233 } 234 235 /* 236 * Given a file path, delete an ACL from it. 237 */ 238 int 239 sys___acl_delete_file(struct __acl_delete_file_args *uap) 240 { 241 struct nlookupdata nd; 242 struct vnode *vp; 243 int error; 244 245 vp = NULL; 246 error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW); 247 if (error == 0) 248 error = nlookup(&nd); 249 if (error == 0) 250 error = cache_vref(nd.nl_ncp, nd.nl_cred, &vp); 251 nlookup_done(&nd); 252 253 if (error == 0) { 254 error = vacl_delete(vp, uap->type); 255 vrele(vp); 256 } 257 return (error); 258 } 259 260 /* 261 * Given a file path, delete an ACL from it. 262 */ 263 int 264 sys___acl_delete_fd(struct __acl_delete_fd_args *uap) 265 { 266 struct thread *td = curthread; 267 struct file *fp; 268 int error; 269 270 KKASSERT(td->td_proc); 271 if ((error = holdvnode(td->td_proc->p_fd, uap->filedes, &fp)) != 0) 272 return(error); 273 error = vacl_delete((struct vnode *)fp->f_data, uap->type); 274 fdrop(fp); 275 return (error); 276 } 277 278 /* 279 * Given a file path, check an ACL for it 280 */ 281 int 282 sys___acl_aclcheck_file(struct __acl_aclcheck_file_args *uap) 283 { 284 struct nlookupdata nd; 285 struct vnode *vp; 286 int error; 287 288 vp = NULL; 289 error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW); 290 if (error == 0) 291 error = nlookup(&nd); 292 if (error == 0) 293 error = cache_vref(nd.nl_ncp, nd.nl_cred, &vp); 294 nlookup_done(&nd); 295 296 if (error == 0) { 297 error = vacl_aclcheck(vp, uap->type, uap->aclp); 298 vrele(vp); 299 } 300 return (error); 301 } 302 303 /* 304 * Given a file descriptor, check an ACL for it 305 */ 306 int 307 sys___acl_aclcheck_fd(struct __acl_aclcheck_fd_args *uap) 308 { 309 struct thread *td = curthread; 310 struct file *fp; 311 int error; 312 313 KKASSERT(td->td_proc); 314 if ((error = holdvnode(td->td_proc->p_fd, uap->filedes, &fp)) != 0) 315 return(error); 316 error = vacl_aclcheck((struct vnode *)fp->f_data, uap->type, uap->aclp); 317 fdrop(fp); 318 return (error); 319 } 320 321