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 1.2 2003/06/17 04:28:41 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 proc *p, struct vnode *vp, acl_type_t type, 53 struct acl *aclp); 54 static int vacl_get_acl(struct proc *p, struct vnode *vp, acl_type_t type, 55 struct acl *aclp); 56 static 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 */ 71 static int 72 vacl_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 */ 91 static int 92 vacl_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 */ 107 static int 108 vacl_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 */ 122 static int 123 vacl_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 */ 145 int 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 */ 164 int 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 */ 182 int 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 */ 198 int 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 */ 214 int 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 */ 232 int 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 */ 248 int 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 */ 266 int 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