xnu-2782.30.5.tar.gz

[apple/xnu.git] / bsd / kern / sysv_ipc.c

diff --git a/bsd/kern/sysv_ipc.c b/bsd/kern/sysv_ipc.c
index 9b63e4fa1a63fc873391fd61fb6b1c3baad118a5..8f56757c4b7f24233683cf289a2140011d8bf24c 100644 (file)
--- a/bsd/kern/sysv_ipc.c
+++ b/bsd/kern/sysv_ipc.c
@@ -1,16 +1,19 @@
 /*
  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
  *
 /*
  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
  *

- * @APPLE_LICENSE_HEADER_START@
- * 
- * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@

  * 
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
  * 
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in

- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ * 
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.

  * 
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * 
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER


@@ -20,7 +23,7 @@
  * Please see the License for the specific language governing rights and
  * limitations under the License.
  * 
  * Please see the License for the specific language governing rights and
  * limitations under the License.
  * 

- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@

  */
 /*     $NetBSD: sysv_ipc.c,v 1.7 1994/06/29 06:33:11 cgd Exp $ */
 
  */
 /*     $NetBSD: sysv_ipc.c,v 1.7 1994/06/29 06:33:11 cgd Exp $ */
 


@@ -57,106 +60,101 @@
 
 #include <sys/param.h>
 #include <sys/ipc.h>
 
 #include <sys/param.h>
 #include <sys/ipc.h>

+#include <sys/stat.h>  /* mode constants */

 #include <sys/ucred.h>
 #include <sys/ucred.h>

+#include <sys/kauth.h>

 
 
 /*
  * Check for ipc permission
 
 
 /*
  * Check for ipc permission

- *
- * XXX: Should pass proc argument so that we can pass 
- * XXX: proc->p_acflag to suser()

  */
 
  */
 

+
+/*
+ * ipc_perm
+ *
+ *     perm->mode                      mode of the object
+ *     mode                            mode bits we want to test
+ *
+ * Returns:    0                       Success
+ *             EPERM
+ *             EACCES
+ *
+ * Notes:      The IPC_M bit is special, in that it may only be granted to
+ *             root, the creating user, or the owning user.
+ *
+ *             This code does not use posix_cred_access() because of the
+ *             need to check both creator and owner separately when we are
+ *             considering a rights grant.  Because of this, we need to do
+ *             two evaluations when the values are inequal, which can lead
+ *             us to defeat the callout avoidance optimization.  So we do
+ *             the work here, inline.  This is less than optimal for any
+ *             future work involving opacity of of POSIX credentials.
+ *
+ *             Setting up the mode_owner / mode_group / mode_world implicitly
+ *             masks the IPC_M bit off.  This is intentional.
+ *
+ *             See the posix_cred_access() implementation for algorithm
+ *             information.
+ */

 int
 int

-ipcperm(cred, perm, mode)
-       struct ucred *cred;
-       struct ipc_perm *perm;
-       int mode;
+ipcperm(kauth_cred_t cred, struct ipc_perm *perm, int mode_req)

 {
 {

-
+       uid_t   uid = kauth_cred_getuid(cred);  /* avoid multiple calls */
+       int     want_mod_controlinfo = (mode_req & IPC_M);
+       int     is_member;
+       mode_t  mode_owner = (perm->mode & S_IRWXU);
+       mode_t  mode_group = (perm->mode & S_IRWXG) << 3;
+       mode_t  mode_world = (perm->mode & S_IRWXO) << 6;
+
+       /* Grant all rights to super user */

        if (!suser(cred, (u_short *)NULL))
                return (0);
 
        if (!suser(cred, (u_short *)NULL))
                return (0);
 

-       /* Check for user match. */
-       if (cred->cr_uid != perm->cuid && cred->cr_uid != perm->uid) {
-               if (mode & IPC_M)
+       /* Grant or deny rights based on ownership */
+       if (uid == perm->cuid || uid == perm->uid) {
+               if (want_mod_controlinfo)
+                       return (0);
+
+               return ((mode_req & mode_owner) == mode_req ? 0 : EACCES);
+       } else {
+               /* everyone else who wants to modify control info is denied */
+               if (want_mod_controlinfo)

                        return (EPERM);
                        return (EPERM);

-               /* Check for group match. */
-               mode >>= 3;
-               if (!groupmember(perm->gid, cred) &&
-                   !groupmember(perm->cgid, cred))
-                       /* Check for `other' match. */
-                       mode >>= 3;

        }
 
        }
 

-       if (mode & IPC_M)
+       /*
+        * Combined group and world rights check, if no owner rights; positive
+        * asssertion of gid/cgid equality avoids an extra callout in the
+        * common case.
+        */
+       if ((mode_req & mode_group & mode_world) == mode_req) {

                return (0);
                return (0);

-       return ((mode & perm->mode) == mode ? 0 : EACCES);
+       } else {
+               if ((mode_req & mode_group) != mode_req) {
+                       if ((!kauth_cred_ismember_gid(cred, perm->gid, &is_member) && is_member) &&
+                           ((perm->gid == perm->cgid) ||
+                            (!kauth_cred_ismember_gid(cred, perm->cgid, &is_member) && is_member))) {
+                               return (EACCES);
+                       } else {
+                               if ((mode_req & mode_world) != mode_req) {
+                                       return (EACCES);
+                               } else {
+                                       return (0);
+                               }
+                       }
+               } else {
+                       if ((!kauth_cred_ismember_gid(cred, perm->gid, &is_member) && is_member) ||
+                           ((perm->gid != perm->cgid) &&
+                            (!kauth_cred_ismember_gid(cred, perm->cgid, &is_member) && is_member))) {
+                               return (0);
+                       } else {
+                               if ((mode_req & mode_world) != mode_req) {
+                                       return (EACCES);
+                               } else {
+                                       return (0);
+                               }
+                       }
+               }
+       }

 }
 }

-
-
-
-/*
- * SYSVMSG stubs
- */
-
-int
-msgsys(p, uap)
-       struct proc *p;
-       /* XXX actually varargs. */
-#if 0
-       struct msgsys_args *uap;
-#else
-       void *uap;
-#endif
-{
-       return(EOPNOTSUPP);
-};
-
-int
-msgctl(p, uap)
-       struct proc *p;
-#if 0
-       register struct msgctl_args *uap;
-#else
-       void *uap;
-#endif
-{
-       return(EOPNOTSUPP);
-};
-
-int
-msgget(p, uap)
-       struct proc *p;
-#if 0
-       register struct msgget_args *uap;
-#else
-       void *uap;
-#endif
-{
-       return(EOPNOTSUPP);
-};
-
-int
-msgsnd(p, uap)
-       struct proc *p;
-#if 0
-       register struct msgsnd_args *uap;
-#else
-       void *uap;
-#endif
-{
-       return(EOPNOTSUPP);
-};
-
-int
-msgrcv(p, uap)
-       struct proc *p;
-#if 0
-       register struct msgrcv_args *uap;
-#else
-       void *uap;
-#endif
-{
-       return(EOPNOTSUPP);
-};