| 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 1.13 2006/05/24 03:23:31 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 | __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 | __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 | __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 | __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 | __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 | __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 | __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 | __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 | |