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 ucred = td->td_ucred; 78 79 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 80 error = VOP_SETACL(vp, type, &inkernacl, ucred); 81 vn_unlock(vp); 82 return(error); 83 } 84 85 /* 86 * Given a vnode, get its ACL. 87 */ 88 static int 89 vacl_get_acl(struct vnode *vp, acl_type_t type, struct acl *aclp) 90 { 91 struct thread *td = curthread; 92 struct acl inkernelacl; 93 struct ucred *ucred; 94 int error; 95 96 ucred = td->td_ucred; 97 error = VOP_GETACL(vp, type, &inkernelacl, ucred); 98 if (error == 0) 99 error = copyout(&inkernelacl, aclp, sizeof(struct acl)); 100 return (error); 101 } 102 103 /* 104 * Given a vnode, delete its ACL. 105 */ 106 static int 107 vacl_delete(struct vnode *vp, acl_type_t type) 108 { 109 struct thread *td = curthread; 110 struct ucred *ucred; 111 int error; 112 113 ucred = td->td_ucred; 114 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 115 error = VOP_SETACL(vp, ACL_TYPE_DEFAULT, 0, ucred); 116 vn_unlock(vp); 117 return (error); 118 } 119 120 /* 121 * Given a vnode, check whether an ACL is appropriate for it 122 */ 123 static int 124 vacl_aclcheck(struct vnode *vp, acl_type_t type, struct acl *aclp) 125 { 126 struct thread *td = curthread; 127 struct ucred *ucred; 128 struct acl inkernelacl; 129 int error; 130 131 ucred = td->td_ucred; 132 error = copyin(aclp, &inkernelacl, sizeof(struct acl)); 133 if (error) 134 return(error); 135 error = VOP_ACLCHECK(vp, type, &inkernelacl, ucred); 136 return (error); 137 } 138 139 /* 140 * syscalls -- convert the path/fd to a vnode, and call vacl_whatever. 141 * Don't need to lock, as the vacl_ code will get/release any locks 142 * required. 143 */ 144 145 /* 146 * Given a file path, get an ACL for it 147 */ 148 int 149 sys___acl_get_file(struct __acl_get_file_args *uap) 150 { 151 struct nlookupdata nd; 152 struct vnode *vp; 153 int error; 154 155 vp = NULL; 156 error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW); 157 if (error == 0) 158 error = nlookup(&nd); 159 if (error == 0) 160 error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp); 161 nlookup_done(&nd); 162 if (error == 0) { 163 error = vacl_get_acl(vp, uap->type, uap->aclp); 164 vrele(vp); 165 } 166 return (error); 167 } 168 169 /* 170 * Given a file path, set an ACL for it 171 */ 172 int 173 sys___acl_set_file(struct __acl_set_file_args *uap) 174 { 175 struct nlookupdata nd; 176 struct vnode *vp; 177 int error; 178 179 vp = NULL; 180 error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW); 181 if (error == 0) 182 error = nlookup(&nd); 183 if (error == 0) 184 error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp); 185 nlookup_done(&nd); 186 if (error == 0) { 187 error = vacl_set_acl(vp, uap->type, uap->aclp); 188 vrele(vp); 189 } 190 return (error); 191 } 192 193 /* 194 * Given a file descriptor, get an ACL for it 195 */ 196 int 197 sys___acl_get_fd(struct __acl_get_fd_args *uap) 198 { 199 struct thread *td = curthread; 200 struct file *fp; 201 int error; 202 203 KKASSERT(td->td_proc); 204 if ((error = holdvnode(td->td_proc->p_fd, uap->filedes, &fp)) != 0) 205 return(error); 206 error = vacl_get_acl((struct vnode *)fp->f_data, uap->type, uap->aclp); 207 fdrop(fp); 208 209 return (error); 210 } 211 212 /* 213 * Given a file descriptor, set an ACL for it 214 */ 215 int 216 sys___acl_set_fd(struct __acl_set_fd_args *uap) 217 { 218 struct thread *td = curthread; 219 struct file *fp; 220 int error; 221 222 KKASSERT(td->td_proc); 223 if ((error = holdvnode(td->td_proc->p_fd, uap->filedes, &fp)) != 0) 224 return(error); 225 error = vacl_set_acl((struct vnode *)fp->f_data, uap->type, uap->aclp); 226 fdrop(fp); 227 return (error); 228 } 229 230 /* 231 * Given a file path, delete an ACL from it. 232 */ 233 int 234 sys___acl_delete_file(struct __acl_delete_file_args *uap) 235 { 236 struct nlookupdata nd; 237 struct vnode *vp; 238 int error; 239 240 vp = NULL; 241 error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW); 242 if (error == 0) 243 error = nlookup(&nd); 244 if (error == 0) 245 error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp); 246 nlookup_done(&nd); 247 248 if (error == 0) { 249 error = vacl_delete(vp, uap->type); 250 vrele(vp); 251 } 252 return (error); 253 } 254 255 /* 256 * Given a file path, delete an ACL from it. 257 */ 258 int 259 sys___acl_delete_fd(struct __acl_delete_fd_args *uap) 260 { 261 struct thread *td = curthread; 262 struct file *fp; 263 int error; 264 265 KKASSERT(td->td_proc); 266 if ((error = holdvnode(td->td_proc->p_fd, uap->filedes, &fp)) != 0) 267 return(error); 268 error = vacl_delete((struct vnode *)fp->f_data, uap->type); 269 fdrop(fp); 270 return (error); 271 } 272 273 /* 274 * Given a file path, check an ACL for it 275 */ 276 int 277 sys___acl_aclcheck_file(struct __acl_aclcheck_file_args *uap) 278 { 279 struct nlookupdata nd; 280 struct vnode *vp; 281 int error; 282 283 vp = NULL; 284 error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW); 285 if (error == 0) 286 error = nlookup(&nd); 287 if (error == 0) 288 error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp); 289 nlookup_done(&nd); 290 291 if (error == 0) { 292 error = vacl_aclcheck(vp, uap->type, uap->aclp); 293 vrele(vp); 294 } 295 return (error); 296 } 297 298 /* 299 * Given a file descriptor, check an ACL for it 300 */ 301 int 302 sys___acl_aclcheck_fd(struct __acl_aclcheck_fd_args *uap) 303 { 304 struct thread *td = curthread; 305 struct file *fp; 306 int error; 307 308 KKASSERT(td->td_proc); 309 if ((error = holdvnode(td->td_proc->p_fd, uap->filedes, &fp)) != 0) 310 return(error); 311 error = vacl_aclcheck((struct vnode *)fp->f_data, uap->type, uap->aclp); 312 fdrop(fp); 313 return (error); 314 } 315 316