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 * $FreeBSD$ 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 49 MALLOC_DEFINE(M_ACL, "acl", "access control list"); 50 51 static int vacl_set_acl(struct proc *p, struct vnode *vp, acl_type_t type, 52 struct acl *aclp); 53 static int vacl_get_acl(struct proc *p, struct vnode *vp, acl_type_t type, 54 struct acl *aclp); 55 static int vacl_aclcheck(struct proc *p, struct vnode *vp, acl_type_t type, 56 struct acl *aclp); 57 58 /* 59 * These calls wrap the real vnode operations, and are called by the 60 * syscall code once the syscall has converted the path or file 61 * descriptor to a vnode (unlocked). The aclp pointer is assumed 62 * still to point to userland, so this should not be consumed within 63 * the kernel except by syscall code. Other code should directly 64 * invoke VOP_{SET,GET}ACL. 65 */ 66 67 /* 68 * Given a vnode, set its ACL. 69 */ 70 static int 71 vacl_set_acl(struct proc *p, struct vnode *vp, acl_type_t type, 72 struct acl *aclp) 73 { 74 struct acl inkernacl; 75 int error; 76 77 error = copyin(aclp, &inkernacl, sizeof(struct acl)); 78 if (error) 79 return(error); 80 VOP_LEASE(vp, p, p->p_ucred, LEASE_WRITE); 81 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 82 error = VOP_SETACL(vp, type, &inkernacl, p->p_ucred, p); 83 VOP_UNLOCK(vp, 0, p); 84 return(error); 85 } 86 87 /* 88 * Given a vnode, get its ACL. 89 */ 90 static int 91 vacl_get_acl(struct proc *p, struct vnode *vp, acl_type_t type, 92 struct acl *aclp) 93 { 94 struct acl inkernelacl; 95 int error; 96 97 VOP_LEASE(vp, p, p->p_ucred, LEASE_WRITE); 98 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 99 error = VOP_GETACL(vp, type, &inkernelacl, p->p_ucred, p); 100 VOP_UNLOCK(vp, 0, p); 101 if (error == 0) 102 error = copyout(&inkernelacl, aclp, sizeof(struct acl)); 103 return (error); 104 } 105 106 /* 107 * Given a vnode, delete its ACL. 108 */ 109 static int 110 vacl_delete(struct proc *p, struct vnode *vp, acl_type_t type) 111 { 112 int error; 113 114 VOP_LEASE(vp, p, p->p_ucred, LEASE_WRITE); 115 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 116 error = VOP_SETACL(vp, ACL_TYPE_DEFAULT, 0, p->p_ucred, p); 117 VOP_UNLOCK(vp, 0, p); 118 return (error); 119 } 120 121 /* 122 * Given a vnode, check whether an ACL is appropriate for it 123 */ 124 static int 125 vacl_aclcheck(struct proc *p, struct vnode *vp, acl_type_t type, 126 struct acl *aclp) 127 { 128 struct acl inkernelacl; 129 int error; 130 131 error = copyin(aclp, &inkernelacl, sizeof(struct acl)); 132 if (error) 133 return(error); 134 error = VOP_ACLCHECK(vp, type, &inkernelacl, p->p_ucred, p); 135 return (error); 136 } 137 138 /* 139 * syscalls -- convert the path/fd to a vnode, and call vacl_whatever. 140 * Don't need to lock, as the vacl_ code will get/release any locks 141 * required. 142 */ 143 144 /* 145 * Given a file path, get an ACL for it 146 */ 147 int 148 __acl_get_file(struct proc *p, struct __acl_get_file_args *uap) 149 { 150 struct nameidata nd; 151 int error; 152 153 /* what flags are required here -- possible not LOCKLEAF? */ 154 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 155 error = namei(&nd); 156 if (error) 157 return(error); 158 error = vacl_get_acl(p, nd.ni_vp, SCARG(uap, type), SCARG(uap, aclp)); 159 NDFREE(&nd, 0); 160 return (error); 161 } 162 163 /* 164 * Given a file path, set an ACL for it 165 */ 166 int 167 __acl_set_file(struct proc *p, struct __acl_set_file_args *uap) 168 { 169 struct nameidata nd; 170 int error; 171 172 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 173 error = namei(&nd); 174 if (error) 175 return(error); 176 error = vacl_set_acl(p, nd.ni_vp, SCARG(uap, type), SCARG(uap, aclp)); 177 NDFREE(&nd, 0); 178 return (error); 179 } 180 181 /* 182 * Given a file descriptor, get an ACL for it 183 */ 184 int 185 __acl_get_fd(struct proc *p, struct __acl_get_fd_args *uap) 186 { 187 struct file *fp; 188 int error; 189 190 error = getvnode(p->p_fd, SCARG(uap, filedes), &fp); 191 if (error) 192 return(error); 193 return vacl_get_acl(p, (struct vnode *)fp->f_data, SCARG(uap, type), 194 SCARG(uap, aclp)); 195 } 196 197 /* 198 * Given a file descriptor, set an ACL for it 199 */ 200 int 201 __acl_set_fd(struct proc *p, struct __acl_set_fd_args *uap) 202 { 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(p, (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 proc *p, struct __acl_delete_file_args *uap) 218 { 219 struct nameidata nd; 220 int error; 221 222 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 223 error = namei(&nd); 224 if (error) 225 return(error); 226 error = vacl_delete(p, nd.ni_vp, SCARG(uap, type)); 227 NDFREE(&nd, 0); 228 return (error); 229 } 230 231 /* 232 * Given a file path, delete an ACL from it. 233 */ 234 int 235 __acl_delete_fd(struct proc *p, struct __acl_delete_fd_args *uap) 236 { 237 struct file *fp; 238 int error; 239 240 error = getvnode(p->p_fd, SCARG(uap, filedes), &fp); 241 if (error) 242 return(error); 243 error = vacl_delete(p, (struct vnode *)fp->f_data, SCARG(uap, type)); 244 return (error); 245 } 246 247 /* 248 * Given a file path, check an ACL for it 249 */ 250 int 251 __acl_aclcheck_file(struct proc *p, struct __acl_aclcheck_file_args *uap) 252 { 253 struct nameidata nd; 254 int error; 255 256 NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p); 257 error = namei(&nd); 258 if (error) 259 return(error); 260 error = vacl_aclcheck(p, nd.ni_vp, SCARG(uap, type), SCARG(uap, aclp)); 261 NDFREE(&nd, 0); 262 return (error); 263 } 264 265 /* 266 * Given a file descriptor, check an ACL for it 267 */ 268 int 269 __acl_aclcheck_fd(struct proc *p, struct __acl_aclcheck_fd_args *uap) 270 { 271 struct file *fp; 272 int error; 273 274 error = getvnode(p->p_fd, SCARG(uap, filedes), &fp); 275 if (error) 276 return(error); 277 return vacl_aclcheck(p, (struct vnode *)fp->f_data, SCARG(uap, type), 278 SCARG(uap, aclp)); 279 } 280