sys/kern/kern_acl.c

   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 1.17 2007/02/19 00:51:54 swildner 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 int vacl_set_acl(struct vnode *vp, acl_type_t type, struct acl *aclp);
  51 static int vacl_get_acl(struct vnode *vp, acl_type_t type, struct acl *aclp);
  52 static int vacl_aclcheck(struct vnode *vp, acl_type_t type, struct acl *aclp);
  53
  54 /*
  55  * These calls wrap the real vnode operations, and are called by the
  56  * syscall code once the syscall has converted the path or file
  57  * descriptor to a vnode (unlocked).  The aclp pointer is assumed
  58  * still to point to userland, so this should not be consumed within
  59  * the kernel except by syscall code.  Other code should directly
  60  * invoke VOP_{SET,GET}ACL.
  61  */
  62
  63 /*
  64  * Given a vnode, set its ACL.
  65  */
  66 static int
  67 vacl_set_acl(struct vnode *vp, acl_type_t type, struct acl *aclp)
  68 {
  69         struct thread *td = curthread;
  70         struct acl inkernacl;
  71         struct ucred *ucred;
  72         int error;
  73
  74         error = copyin(aclp, &inkernacl, sizeof(struct acl));
  75         if (error)
  76                 return(error);
  77         KKASSERT(td->td_proc);
  78         ucred = td->td_proc->p_ucred;
  79
  80         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
  81         error = VOP_SETACL(vp, type, &inkernacl, ucred);
  82         vn_unlock(vp);
  83         return(error);
  84 }
  85
  86 /*
  87  * Given a vnode, get its ACL.
  88  */
  89 static int
  90 vacl_get_acl(struct vnode *vp, acl_type_t type, struct acl *aclp)
  91 {
  92         struct thread *td = curthread;
  93         struct acl inkernelacl;
  94         struct ucred *ucred;
  95         int error;
  96
  97         KKASSERT(td->td_proc);
  98         ucred = td->td_proc->p_ucred;
  99         error = VOP_GETACL(vp, type, &inkernelacl, ucred);
 100         if (error == 0)
 101                 error = copyout(&inkernelacl, aclp, sizeof(struct acl));
 102         return (error);
 103 }
 104
 105 /*
 106  * Given a vnode, delete its ACL.
 107  */
 108 static int
 109 vacl_delete(struct vnode *vp, acl_type_t type)
 110 {
 111         struct thread *td = curthread;
 112         struct ucred *ucred;
 113         int error;
 114
 115         KKASSERT(td->td_proc);
 116         ucred = td->td_proc->p_ucred;
 117         vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 118         error = VOP_SETACL(vp, ACL_TYPE_DEFAULT, 0, ucred);
 119         vn_unlock(vp);
 120         return (error);
 121 }
 122
 123 /*
 124  * Given a vnode, check whether an ACL is appropriate for it
 125  */
 126 static int
 127 vacl_aclcheck(struct vnode *vp, acl_type_t type, struct acl *aclp)
 128 {
 129         struct thread *td = curthread;
 130         struct ucred *ucred;
 131         struct acl inkernelacl;
 132         int error;
 133
 134         KKASSERT(td->td_proc);
 135         ucred = td->td_proc->p_ucred;
 136         error = copyin(aclp, &inkernelacl, sizeof(struct acl));
 137         if (error)
 138                 return(error);
 139         error = VOP_ACLCHECK(vp, type, &inkernelacl, ucred);
 140         return (error);
 141 }
 142
 143 /*
 144  * syscalls -- convert the path/fd to a vnode, and call vacl_whatever.
 145  * Don't need to lock, as the vacl_ code will get/release any locks
 146  * required.
 147  */
 148
 149 /*
 150  * Given a file path, get an ACL for it
 151  */
 152 int
 153 sys___acl_get_file(struct __acl_get_file_args *uap)
 154 {
 155         struct nlookupdata nd;
 156         struct vnode *vp;
 157         int error;
 158
 159         vp = NULL;
 160         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
 161         if (error == 0)
 162                 error = nlookup(&nd);
 163         if (error == 0)
 164                 error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp);
 165         nlookup_done(&nd);
 166         if (error == 0) {
 167                 error = vacl_get_acl(vp, uap->type, uap->aclp);
 168                 vrele(vp);
 169         }
 170         return (error);
 171 }
 172
 173 /*
 174  * Given a file path, set an ACL for it
 175  */
 176 int
 177 sys___acl_set_file(struct __acl_set_file_args *uap)
 178 {
 179         struct nlookupdata nd;
 180         struct vnode *vp;
 181         int error;
 182
 183         vp = NULL;
 184         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
 185         if (error == 0)
 186                 error = nlookup(&nd);
 187         if (error == 0)
 188                 error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp);
 189         nlookup_done(&nd);
 190         if (error == 0) {
 191                 error = vacl_set_acl(vp, uap->type, uap->aclp);
 192                 vrele(vp);
 193         }
 194         return (error);
 195 }
 196
 197 /*
 198  * Given a file descriptor, get an ACL for it
 199  */
 200 int
 201 sys___acl_get_fd(struct __acl_get_fd_args *uap)
 202 {
 203         struct thread *td = curthread;
 204         struct file *fp;
 205         int error;
 206
 207         KKASSERT(td->td_proc);
 208         if ((error = holdvnode(td->td_proc->p_fd, uap->filedes, &fp)) != 0)
 209                 return(error);
 210         error = vacl_get_acl((struct vnode *)fp->f_data, uap->type, uap->aclp);
 211         fdrop(fp);
 212         return (error);
 213 }
 214
 215 /*
 216  * Given a file descriptor, set an ACL for it
 217  */
 218 int
 219 sys___acl_set_fd(struct __acl_set_fd_args *uap)
 220 {
 221         struct thread *td = curthread;
 222         struct file *fp;
 223         int error;
 224
 225         KKASSERT(td->td_proc);
 226         if ((error = holdvnode(td->td_proc->p_fd, uap->filedes, &fp)) != 0)
 227                 return(error);
 228         error = vacl_set_acl((struct vnode *)fp->f_data, uap->type, uap->aclp);
 229         fdrop(fp);
 230         return (error);
 231 }
 232
 233 /*
 234  * Given a file path, delete an ACL from it.
 235  */
 236 int
 237 sys___acl_delete_file(struct __acl_delete_file_args *uap)
 238 {
 239         struct nlookupdata nd;
 240         struct vnode *vp;
 241         int error;
 242
 243         vp = NULL;
 244         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
 245         if (error == 0)
 246                 error = nlookup(&nd);
 247         if (error == 0)
 248                 error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp);
 249         nlookup_done(&nd);
 250
 251         if (error == 0) {
 252                 error = vacl_delete(vp, uap->type);
 253                 vrele(vp);
 254         }
 255         return (error);
 256 }
 257
 258 /*
 259  * Given a file path, delete an ACL from it.
 260  */
 261 int
 262 sys___acl_delete_fd(struct __acl_delete_fd_args *uap)
 263 {
 264         struct thread *td = curthread;
 265         struct file *fp;
 266         int error;
 267
 268         KKASSERT(td->td_proc);
 269         if ((error = holdvnode(td->td_proc->p_fd, uap->filedes, &fp)) != 0)
 270                 return(error);
 271         error = vacl_delete((struct vnode *)fp->f_data, uap->type);
 272         fdrop(fp);
 273         return (error);
 274 }
 275
 276 /*
 277  * Given a file path, check an ACL for it
 278  */
 279 int
 280 sys___acl_aclcheck_file(struct __acl_aclcheck_file_args *uap)
 281 {
 282         struct nlookupdata nd;
 283         struct vnode *vp;
 284         int error;
 285
 286         vp = NULL;
 287         error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
 288         if (error == 0)
 289                 error = nlookup(&nd);
 290         if (error == 0)
 291                 error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp);
 292         nlookup_done(&nd);
 293
 294         if (error == 0) {
 295                 error = vacl_aclcheck(vp, uap->type, uap->aclp);
 296                 vrele(vp);
 297         }
 298         return (error);
 299 }
 300
 301 /*
 302  * Given a file descriptor, check an ACL for it
 303  */
 304 int
 305 sys___acl_aclcheck_fd(struct __acl_aclcheck_fd_args *uap)
 306 {
 307         struct thread *td = curthread;
 308         struct file *fp;
 309         int error;
 310
 311         KKASSERT(td->td_proc);
 312         if ((error = holdvnode(td->td_proc->p_fd, uap->filedes, &fp)) != 0)
 313                 return(error);
 314         error = vacl_aclcheck((struct vnode *)fp->f_data, uap->type, uap->aclp);
 315         fdrop(fp);
 316         return (error);
 317 }
 318