osfmk/kern/audit_sessionport.c

   1 /*
   2  * Copyright (c) 2008 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 #include <mach/mach_types.h>
  29 #include <mach/notify.h>
  30 #include <ipc/ipc_port.h>
  31 #include <kern/ipc_kobject.h>
  32 #include <kern/audit_sessionport.h>
  33 #include <libkern/OSAtomic.h>
  34
  35 #if CONFIG_AUDIT
  36 /*
  37  * audit_session_mksend
  38  *
  39  * Description: Obtain a send right for given audit session.
  40  *
  41  * Parameters:  *aia_p          Audit session information to assosiate with
  42  *                              the new port.
  43  *              *sessionport    Pointer to the current session port.  This may
  44  *                              actually be set to IPC_PORT_NULL.
  45  *
  46  * Returns:     !NULL           Resulting send right.
  47  *              NULL            Failed to allocate port (due to lack of memory
  48  *                              resources).
  49  *
  50  * Assumptions: Caller holds a reference on the session during the call.
  51  *              If there were no outstanding send rights against the port,
  52  *              hold a reference on the session and arm a new no-senders
  53  *              notification to determine when to release that reference.
  54  *              Otherwise, by creating an additional send right, we share
  55  *              the port's reference until all send rights go away.
  56  */
  57 ipc_port_t
  58 audit_session_mksend(struct auditinfo_addr *aia_p, ipc_port_t *sessionport)
  59 {
  60         audit_session_aiaref(aia_p);
  61         if (!ipc_kobject_make_send_lazy_alloc_port(sessionport,
  62             (ipc_kobject_t)aia_p, IKOT_AU_SESSIONPORT, false, 0)) {
  63                 audit_session_aiaunref(aia_p);
  64         }
  65
  66         return *sessionport;
  67 }
  68
  69
  70 /*
  71  * audit_session_porttoaia
  72  *
  73  * Description: Obtain the audit session info associated with the given port.
  74  *
  75  * Parameters: port             A Mach port.
  76  *
  77  * Returns:    NULL             The given Mach port did not reference audit
  78  *                              session info.
  79  *             !NULL            The audit session info that is associated with
  80  *                              the Mach port.
  81  *
  82  * Notes: The caller must have a reference on the sessionport.
  83  */
  84 struct auditinfo_addr *
  85 audit_session_porttoaia(ipc_port_t port)
  86 {
  87         struct auditinfo_addr *aia_p = NULL;
  88
  89         if (IP_VALID(port)) {
  90                 ip_lock(port);
  91                 if (IKOT_AU_SESSIONPORT == ip_kotype(port)) {
  92                         require_ip_active(port);
  93                         aia_p = (struct auditinfo_addr *)ip_get_kobject(port);
  94                 }
  95                 ip_unlock(port);
  96         }
  97
  98         return aia_p;
  99 }
 100
 101
 102 /*
 103  * audit_session_nosenders
 104  *
 105  * Description: Handle a no-senders notification for a sessionport.
 106  *
 107  * Parameters: msg              A Mach no-senders notification message.
 108  *
 109  * Notes: It is possible that new send rights are created after a
 110  *        no-senders notification has been sent, but they will be protected
 111  *        by another aia reference.
 112  */
 113 void
 114 audit_session_nosenders(mach_msg_header_t *msg)
 115 {
 116         mach_no_senders_notification_t *notification = (void *)msg;
 117         ipc_port_t port = notification->not_header.msgh_remote_port;
 118         struct auditinfo_addr *port_aia_p = NULL;
 119
 120         require_ip_active(port);
 121         assert(IKOT_AU_SESSIONPORT == ip_kotype(port));
 122         port_aia_p = (struct auditinfo_addr *)ip_get_kobject(port);
 123         assert(NULL != port_aia_p);
 124
 125         audit_session_aiaunref(port_aia_p);
 126 }
 127
 128 void
 129 audit_session_portdestroy(ipc_port_t *sessionport)
 130 {
 131         ipc_port_t port = *sessionport;
 132
 133         if (IP_VALID(port)) {
 134                 require_ip_active(port);
 135                 assert(IKOT_AU_SESSIONPORT == ip_kotype(port));
 136                 ipc_kobject_set_atomically(port, IKO_NULL, IKOT_NONE);
 137                 ipc_port_dealloc_kernel(port);
 138                 *sessionport = IP_NULL;
 139         }
 140 }
 141 #endif /* CONFIG_AUDIT */