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 1.3 2003/06/23 17:55:41 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/namei.h> 43 #include <sys/file.h> 44 #include <sys/proc.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 proc *p = curproc; 72 struct acl inkernacl; 73 int error; 74 75 error = copyin(aclp, &inkernacl, sizeof(struct acl)); 76 if (error) 77 return(error); 78 VOP_LEASE(vp, p, p->p_ucred, LEASE_WRITE); 79 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 80 error = VOP_SETACL(vp, type, &inkernacl, p->p_ucred, p); 81 VOP_UNLOCK(vp, 0, p); 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 proc *p = curproc; 92 struct acl inkernelacl; 93 int error; 94 95 error = VOP_GETACL(vp, type, &inkernelacl, p->p_ucred, p); 96 if (error == 0) 97 error = copyout(&inkernelacl, aclp, sizeof(struct acl)); 98 return (error); 99 } 100 101 /* 102 * Given a vnode, delete its ACL. 103 */ 104 static int 105 vacl_delete(struct vnode *vp, acl_type_t type) 106 { 107 struct proc *p = curproc; 108 int error; 109 110 VOP_LEASE(vp, p, p->p_ucred, LEASE_WRITE); 111 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 112 error = VOP_SETACL(vp, ACL_TYPE_DEFAULT, 0, p->p_ucred, p); 113 VOP_UNLOCK(vp, 0, p); 114 return (error); 115 } 116 117 /* 118 * Given a vnode, check whether an ACL is appropriate for it 119 */ 120 static int 121 vacl_aclcheck(struct vnode *vp, acl_type_t type, struct acl *aclp) 122 { 123 struct proc *p = curproc; 124 struct acl inkernelacl; 125 int error; 126 127 error = copyin(aclp, &inkernelacl, sizeof(struct acl)); 128 if (error) 129 return(error); 130 error = VOP_ACLCHECK(vp, type, &inkernelacl, p->p_ucred, p); 131 return (error); 132 } 133 134 /* 135 * syscalls -- convert the path/fd to a vnode, and call vacl_whatever. 136 * Don't need to lock, as the vacl_ code will get/release any locks 137 * required. 138 */ 139 140 /* 141 * Given a file path, get an ACL for it 142 */ 143 int 144 __acl_get_file(struct __acl_get_file_args *uap) 145 { 146 struct proc *p = curproc; 147 struct nameidata nd; 148 int error; 149 150 /* what flags are required here -- possible not LOCKLEAF? */ 151 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 152 error = namei(&nd); 153 if (error) 154 return(error); 155 error = vacl_get_acl(nd.ni_vp, SCARG(uap, type), SCARG(uap, aclp)); 156 NDFREE(&nd, 0); 157 return (error); 158 } 159 160 /* 161 * Given a file path, set an ACL for it 162 */ 163 int 164 __acl_set_file(struct __acl_set_file_args *uap) 165 { 166 struct proc *p = curproc; 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(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 */ 182 int 183 __acl_get_fd(struct __acl_get_fd_args *uap) 184 { 185 struct proc *p = curproc; 186 struct file *fp; 187 int error; 188 189 error = getvnode(p->p_fd, SCARG(uap, filedes), &fp); 190 if (error) 191 return(error); 192 return vacl_get_acl((struct vnode *)fp->f_data, SCARG(uap, type), 193 SCARG(uap, aclp)); 194 } 195 196 /* 197 * Given a file descriptor, set an ACL for it 198 */ 199 int 200 __acl_set_fd(struct __acl_set_fd_args *uap) 201 { 202 struct proc *p = curproc; 203 struct file *fp; 204 int error; 205 206 error = getvnode(p->p_fd, SCARG(uap, filedes), &fp); 207 if (error) 208 return(error); 209 return vacl_set_acl((struct vnode *)fp->f_data, SCARG(uap, type), 210 SCARG(uap, aclp)); 211 } 212 213 /* 214 * Given a file path, delete an ACL from it. 215 */ 216 int 217 __acl_delete_file(struct __acl_delete_file_args *uap) 218 { 219 struct proc *p = curproc; 220 struct nameidata nd; 221 int error; 222 223 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 224 error = namei(&nd); 225 if (error) 226 return(error); 227 error = vacl_delete(nd.ni_vp, SCARG(uap, type)); 228 NDFREE(&nd, 0); 229 return (error); 230 } 231 232 /* 233 * Given a file path, delete an ACL from it. 234 */ 235 int 236 __acl_delete_fd(struct __acl_delete_fd_args *uap) 237 { 238 struct proc *p = curproc; 239 struct file *fp; 240 int error; 241 242 error = getvnode(p->p_fd, SCARG(uap, filedes), &fp); 243 if (error) 244 return(error); 245 error = vacl_delete((struct vnode *)fp->f_data, SCARG(uap, type)); 246 return (error); 247 } 248 249 /* 250 * Given a file path, check an ACL for it 251 */ 252 int 253 __acl_aclcheck_file(struct __acl_aclcheck_file_args *uap) 254 { 255 struct proc *p = curproc; 256 struct nameidata nd; 257 int error; 258 259 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 260 error = namei(&nd); 261 if (error) 262 return(error); 263 error = vacl_aclcheck(nd.ni_vp, SCARG(uap, type), SCARG(uap, aclp)); 264 NDFREE(&nd, 0); 265 return (error); 266 } 267 268 /* 269 * Given a file descriptor, check an ACL for it 270 */ 271 int 272 __acl_aclcheck_fd(struct __acl_aclcheck_fd_args *uap) 273 { 274 struct proc *p = curproc; 275 struct file *fp; 276 int error; 277 278 error = getvnode(p->p_fd, SCARG(uap, filedes), &fp); 279 if (error) 280 return(error); 281 return vacl_aclcheck((struct vnode *)fp->f_data, SCARG(uap, type), 282 SCARG(uap, aclp)); 283 } 284