vfs_acl.c revision 56272
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: head/sys/kern/vfs_acl.c 56272 2000-01-19 06:07:34Z rwatson $ 27 */ 28 29/* 30 * Generic routines to support file system ACLs, at a syntactic level 31 * Semantics are the responsibility of the underlying file system 32 */ 33 34#include <sys/param.h> 35#include <sys/systm.h> 36#include <sys/sysproto.h> 37#include <sys/kernel.h> 38#include <sys/malloc.h> 39#include <sys/vnode.h> 40#include <sys/lock.h> 41#include <sys/namei.h> 42#include <sys/file.h> 43#include <sys/proc.h> 44#include <sys/sysent.h> 45#include <sys/errno.h> 46#include <sys/stat.h> 47#include <sys/acl.h> 48#include <vm/vm_zone.h> 49 50static MALLOC_DEFINE(M_ACL, "acl", "access control list"); 51 52static int vacl_set_acl(struct proc *p, struct vnode *vp, acl_type_t type, 53 struct acl *aclp); 54static int vacl_get_acl(struct proc *p, struct vnode *vp, acl_type_t type, 55 struct acl *aclp); 56static int vacl_aclcheck(struct proc *p, struct vnode *vp, acl_type_t type, 57 struct acl *aclp); 58 59/* 60 * These calls wrap the real vnode operations, and are called by the 61 * syscall code once the syscall has converted the path or file 62 * descriptor to a vnode (unlocked). The aclp pointer is assumed 63 * still to point to userland, so this should not be consumed within 64 * the kernel except by syscall code. Other code should directly 65 * invoke VOP_{SET,GET}ACL. 66 */ 67 68/* 69 * Given a vnode, set its ACL. 70 */ 71static int 72vacl_set_acl(struct proc *p, struct vnode *vp, acl_type_t type, 73 struct acl *aclp) 74{ 75 struct acl inkernacl; 76 int error; 77 78 error = copyin(aclp, &inkernacl, sizeof(struct acl)); 79 if (error) 80 return(error); 81 VOP_LEASE(vp, p, p->p_ucred, LEASE_WRITE); 82 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 83 error = VOP_SETACL(vp, type, &inkernacl, p->p_ucred, p); 84 VOP_UNLOCK(vp, 0, p); 85 return(error); 86} 87 88/* 89 * Given a vnode, get its ACL. 90 */ 91static int 92vacl_get_acl(struct proc *p, struct vnode *vp, acl_type_t type, 93 struct acl *aclp) 94{ 95 struct acl inkernelacl; 96 int error; 97 98 error = VOP_GETACL(vp, type, &inkernelacl, p->p_ucred, p); 99 if (error == 0) 100 error = copyout(&inkernelacl, aclp, sizeof(struct acl)); 101 return (error); 102} 103 104/* 105 * Given a vnode, delete its ACL. 106 */ 107static int 108vacl_delete(struct proc *p, struct vnode *vp, acl_type_t type) 109{ 110 int error; 111 112 VOP_LEASE(vp, p, p->p_ucred, LEASE_WRITE); 113 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 114 error = VOP_SETACL(vp, ACL_TYPE_DEFAULT, 0, p->p_ucred, p); 115 VOP_UNLOCK(vp, 0, p); 116 return (error); 117} 118 119/* 120 * Given a vnode, check whether an ACL is appropriate for it 121 */ 122static int 123vacl_aclcheck(struct proc *p, struct vnode *vp, acl_type_t type, 124 struct acl *aclp) 125{ 126 struct acl inkernelacl; 127 int error; 128 129 error = copyin(aclp, &inkernelacl, sizeof(struct acl)); 130 if (error) 131 return(error); 132 error = VOP_ACLCHECK(vp, type, &inkernelacl, p->p_ucred, p); 133 return (error); 134} 135 136/* 137 * syscalls -- convert the path/fd to a vnode, and call vacl_whatever. 138 * Don't need to lock, as the vacl_ code will get/release any locks 139 * required. 140 */ 141 142/* 143 * Given a file path, get an ACL for it 144 */ 145int 146__acl_get_file(struct proc *p, struct __acl_get_file_args *uap) 147{ 148 struct nameidata nd; 149 int error; 150 151 /* what flags are required here -- possible not LOCKLEAF? */ 152 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 153 error = namei(&nd); 154 if (error) 155 return(error); 156 error = vacl_get_acl(p, nd.ni_vp, SCARG(uap, type), SCARG(uap, aclp)); 157 NDFREE(&nd, 0); 158 return (error); 159} 160 161/* 162 * Given a file path, set an ACL for it 163 */ 164int 165__acl_set_file(struct proc *p, struct __acl_set_file_args *uap) 166{ 167 struct nameidata nd; 168 int error; 169 170 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 171 error = namei(&nd); 172 if (error) 173 return(error); 174 error = vacl_set_acl(p, nd.ni_vp, SCARG(uap, type), SCARG(uap, aclp)); 175 NDFREE(&nd, 0); 176 return (error); 177} 178 179/* 180 * Given a file descriptor, get an ACL for it 181 */ 182int 183__acl_get_fd(struct proc *p, struct __acl_get_fd_args *uap) 184{ 185 struct file *fp; 186 int error; 187 188 error = getvnode(p->p_fd, SCARG(uap, filedes), &fp); 189 if (error) 190 return(error); 191 return vacl_get_acl(p, (struct vnode *)fp->f_data, SCARG(uap, type), 192 SCARG(uap, aclp)); 193} 194 195/* 196 * Given a file descriptor, set an ACL for it 197 */ 198int 199__acl_set_fd(struct proc *p, struct __acl_set_fd_args *uap) 200{ 201 struct file *fp; 202 int error; 203 204 error = getvnode(p->p_fd, SCARG(uap, filedes), &fp); 205 if (error) 206 return(error); 207 return vacl_set_acl(p, (struct vnode *)fp->f_data, SCARG(uap, type), 208 SCARG(uap, aclp)); 209} 210 211/* 212 * Given a file path, delete an ACL from it. 213 */ 214int 215__acl_delete_file(struct proc *p, struct __acl_delete_file_args *uap) 216{ 217 struct nameidata nd; 218 int error; 219 220 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 221 error = namei(&nd); 222 if (error) 223 return(error); 224 error = vacl_delete(p, nd.ni_vp, SCARG(uap, type)); 225 NDFREE(&nd, 0); 226 return (error); 227} 228 229/* 230 * Given a file path, delete an ACL from it. 231 */ 232int 233__acl_delete_fd(struct proc *p, struct __acl_delete_fd_args *uap) 234{ 235 struct file *fp; 236 int error; 237 238 error = getvnode(p->p_fd, SCARG(uap, filedes), &fp); 239 if (error) 240 return(error); 241 error = vacl_delete(p, (struct vnode *)fp->f_data, SCARG(uap, type)); 242 return (error); 243} 244 245/* 246 * Given a file path, check an ACL for it 247 */ 248int 249__acl_aclcheck_file(struct proc *p, struct __acl_aclcheck_file_args *uap) 250{ 251 struct nameidata nd; 252 int error; 253 254 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 255 error = namei(&nd); 256 if (error) 257 return(error); 258 error = vacl_aclcheck(p, nd.ni_vp, SCARG(uap, type), SCARG(uap, aclp)); 259 NDFREE(&nd, 0); 260 return (error); 261} 262 263/* 264 * Given a file descriptor, check an ACL for it 265 */ 266int 267__acl_aclcheck_fd(struct proc *p, struct __acl_aclcheck_fd_args *uap) 268{ 269 struct file *fp; 270 int error; 271 272 error = getvnode(p->p_fd, SCARG(uap, filedes), &fp); 273 if (error) 274 return(error); 275 return vacl_aclcheck(p, (struct vnode *)fp->f_data, SCARG(uap, type), 276 SCARG(uap, aclp)); 277} 278