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
audit_session_mksend(struct auditinfo_addr * aia_p,ipc_port_t * sessionport)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,
63 IPC_KOBJECT_ALLOC_NONE, 0)) {
64 audit_session_aiaunref(aia_p);
65 }
66
67 return *sessionport;
68 }
69
70
71 /*
72 * audit_session_porttoaia
73 *
74 * Description: Obtain the audit session info associated with the given port.
75 *
76 * Parameters: port A Mach port.
77 *
78 * Returns: NULL The given Mach port did not reference audit
79 * session info.
80 * !NULL The audit session info that is associated with
81 * the Mach port.
82 *
83 * Notes: The caller must hold an outstanding send-right on the sessionport.
84 */
85 struct auditinfo_addr *
audit_session_porttoaia(ipc_port_t port)86 audit_session_porttoaia(ipc_port_t port)
87 {
88 struct auditinfo_addr *aia_p = NULL;
89
90 if (IP_VALID(port)) {
91 aia_p = ipc_kobject_get_stable(port, IKOT_AU_SESSIONPORT);
92 }
93
94 return aia_p;
95 }
96
97
98 /*
99 * audit_session_no_senders
100 *
101 * Description: Handle a no-senders notification for a sessionport.
102 *
103 * Notes: It is possible that new send rights are created after a
104 * no-senders notification has been sent, but they will be protected
105 * by another aia reference.
106 */
107 static void
audit_session_no_senders(ipc_port_t port,__unused mach_port_mscount_t mscount)108 audit_session_no_senders(ipc_port_t port, __unused mach_port_mscount_t mscount)
109 {
110 struct auditinfo_addr *aia_p = NULL;
111
112 aia_p = ipc_kobject_get_stable(port, IKOT_AU_SESSIONPORT);
113 assert(NULL != aia_p);
114
115 audit_session_aiaunref(aia_p);
116 }
117
118 /*
119 * audit_session_portdestroy
120 *
121 * Description: Destroy the kobject associated with the audit_session
122 *
123 * Notes: It is called when there is no outstanding references on the aia
124 * anymore (it also won't have any outstanding send rights)
125 */
126 void
audit_session_portdestroy(ipc_port_t * sessionport)127 audit_session_portdestroy(ipc_port_t *sessionport)
128 {
129 ipc_port_t port = *sessionport;
130
131 *sessionport = IP_NULL;
132 if (IP_VALID(port)) {
133 ipc_kobject_dealloc_port(port, 0, IKOT_AU_SESSIONPORT);
134 }
135 }
136
137 IPC_KOBJECT_DEFINE(IKOT_AU_SESSIONPORT,
138 .iko_op_stable = true,
139 .iko_op_no_senders = audit_session_no_senders);
140
141 #endif /* CONFIG_AUDIT */
142