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 1.4 2003/06/25 03:55:57 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/namei.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 thread *td = curthread; 160 struct nameidata nd; 161 int error; 162 163 /* what flags are required here -- possible not LOCKLEAF? */ 164 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), td); 165 error = namei(&nd); 166 if (error) 167 return(error); 168 error = vacl_get_acl(nd.ni_vp, SCARG(uap, type), SCARG(uap, aclp)); 169 NDFREE(&nd, 0); 170 return (error); 171 } 172 173 /* 174 * Given a file path, set an ACL for it 175 */ 176 int 177 __acl_set_file(struct __acl_set_file_args *uap) 178 { 179 struct thread *td = curthread; 180 struct nameidata nd; 181 int error; 182 183 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), td); 184 error = namei(&nd); 185 if (error) 186 return(error); 187 error = vacl_set_acl(nd.ni_vp, SCARG(uap, type), SCARG(uap, aclp)); 188 NDFREE(&nd, 0); 189 return (error); 190 } 191 192 /* 193 * Given a file descriptor, get an ACL for it 194 */ 195 int 196 __acl_get_fd(struct __acl_get_fd_args *uap) 197 { 198 struct thread *td = curthread; 199 struct file *fp; 200 int error; 201 202 KKASSERT(td->td_proc); 203 error = getvnode(td->td_proc->p_fd, SCARG(uap, filedes), &fp); 204 if (error) 205 return(error); 206 return vacl_get_acl((struct vnode *)fp->f_data, SCARG(uap, type), 207 SCARG(uap, aclp)); 208 } 209 210 /* 211 * Given a file descriptor, set an ACL for it 212 */ 213 int 214 __acl_set_fd(struct __acl_set_fd_args *uap) 215 { 216 struct thread *td = curthread; 217 struct file *fp; 218 int error; 219 220 KKASSERT(td->td_proc); 221 error = getvnode(td->td_proc->p_fd, SCARG(uap, filedes), &fp); 222 if (error) 223 return(error); 224 return vacl_set_acl((struct vnode *)fp->f_data, SCARG(uap, type), 225 SCARG(uap, aclp)); 226 } 227 228 /* 229 * Given a file path, delete an ACL from it. 230 */ 231 int 232 __acl_delete_file(struct __acl_delete_file_args *uap) 233 { 234 struct thread *td = curthread; 235 struct nameidata nd; 236 int error; 237 238 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), td); 239 error = namei(&nd); 240 if (error) 241 return(error); 242 error = vacl_delete(nd.ni_vp, SCARG(uap, type)); 243 NDFREE(&nd, 0); 244 return (error); 245 } 246 247 /* 248 * Given a file path, delete an ACL from it. 249 */ 250 int 251 __acl_delete_fd(struct __acl_delete_fd_args *uap) 252 { 253 struct thread *td = curthread; 254 struct file *fp; 255 int error; 256 257 KKASSERT(td->td_proc); 258 error = getvnode(td->td_proc->p_fd, SCARG(uap, filedes), &fp); 259 if (error) 260 return(error); 261 error = vacl_delete((struct vnode *)fp->f_data, SCARG(uap, type)); 262 return (error); 263 } 264 265 /* 266 * Given a file path, check an ACL for it 267 */ 268 int 269 __acl_aclcheck_file(struct __acl_aclcheck_file_args *uap) 270 { 271 struct thread *td = curthread; 272 struct nameidata nd; 273 int error; 274 275 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), td); 276 error = namei(&nd); 277 if (error) 278 return(error); 279 error = vacl_aclcheck(nd.ni_vp, SCARG(uap, type), SCARG(uap, aclp)); 280 NDFREE(&nd, 0); 281 return (error); 282 } 283 284 /* 285 * Given a file descriptor, check an ACL for it 286 */ 287 int 288 __acl_aclcheck_fd(struct __acl_aclcheck_fd_args *uap) 289 { 290 struct thread *td = curthread; 291 struct file *fp; 292 int error; 293 294 KKASSERT(td->td_proc); 295 error = getvnode(td->td_proc->p_fd, SCARG(uap, filedes), &fp); 296 if (error) 297 return(error); 298 return vacl_aclcheck((struct vnode *)fp->f_data, SCARG(uap, type), 299 SCARG(uap, aclp)); 300 } 301