1 /*
2  * Mach Operating System
3  * Copyright (c) 1991,1990 Carnegie Mellon University
4  * All Rights Reserved.
5  *
6  * Permission to use, copy, modify and distribute this software and its
7  * documentation is hereby granted, provided that both the copyright
8  * notice and this permission notice appear in all copies of the
9  * software, derivative works or modified versions, and any portions
10  * thereof, and that both notices appear in supporting documentation.
11  *
12  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
13  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
14  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
15  *
16  * Carnegie Mellon requests users of this software to return to
17  *
18  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
19  *  School of Computer Science
20  *  Carnegie Mellon University
21  *  Pittsburgh PA 15213-3890
22  *
23  * any improvements or extensions that they make and grant Carnegie Mellon
24  * the rights to redistribute these changes.
25  */
26 /*
27  * (pre-GNU) HISTORY
28  *
29  * Revision 2.4  91/05/14  17:53:15  mrt
30  * 	Correcting copyright
31  *
32  * Revision 2.3  91/02/14  14:17:43  mrt
33  * 	Added new Mach copyright
34  * 	[91/02/13  12:44:15  mrt]
35  *
36  * Revision 2.2  90/08/06  17:24:22  rpd
37  * 	Created.
38  *
39  */
40 
41 #if 1
42 #include <mach.h>
43 #else
44 /* This is what CMU did, but that fails to declare some used functions.  */
45 #include <mach/port.h>
46 #include <mach/message.h>
47 #include <mach_init.h>
48 #endif
49 
50 static void mach_msg_destroy_port(mach_port_t, mach_msg_type_name_t);
51 static void mach_msg_destroy_memory(vm_offset_t, vm_size_t);
52 
53 /*
54  *	Routine:	mach_msg_destroy
55  *	Purpose:
56  *		Deallocates all port rights and out-of-line memory
57  *		found in a received message.
58  */
59 
60 void
__mach_msg_destroy(mach_msg_header_t * msg)61 __mach_msg_destroy (mach_msg_header_t *msg)
62 {
63     mach_msg_bits_t mbits = msg->msgh_bits;
64 
65     /*
66      *	The msgh_local_port field doesn't hold a port right.
67      *	The receive operation consumes the destination port right.
68      */
69 
70     mach_msg_destroy_port(msg->msgh_remote_port, MACH_MSGH_BITS_REMOTE(mbits));
71 
72     if (mbits & MACH_MSGH_BITS_COMPLEX) {
73 #ifdef MACH_MSG_PORT_DESCRIPTOR
74 	mach_msg_body_t		*body;
75 	mach_msg_descriptor_t	*saddr, *eaddr;
76 
77 	body = (mach_msg_body_t *) (msg + 1);
78 	saddr = (mach_msg_descriptor_t *)
79 			((mach_msg_base_t *) msg + 1);
80 	eaddr =  saddr + body->msgh_descriptor_count;
81 
82 	for  ( ; saddr < eaddr; saddr++) {
83 	    switch (saddr->type.type) {
84 
85 	        case MACH_MSG_PORT_DESCRIPTOR: {
86 		    mach_msg_port_descriptor_t *dsc;
87 
88 		    /*
89 		     * Destroy port rights carried in the message
90 		     */
91 		    dsc = &saddr->port;
92 		    mach_msg_destroy_port(dsc->name, dsc->disposition);
93 		    break;
94 	        }
95 
96 	        case MACH_MSG_OOL_DESCRIPTOR : {
97 		    mach_msg_ool_descriptor_t *dsc;
98 
99 		    /*
100 		     * Destroy memory carried in the message
101 		     */
102 		    dsc = &saddr->out_of_line;
103 		    if (dsc->deallocate) {
104 		        mach_msg_destroy_memory((vm_offset_t)dsc->address,
105 						dsc->size);
106 		    }
107 		    break;
108 	        }
109 
110 	        case MACH_MSG_OOL_PORTS_DESCRIPTOR : {
111 		    mach_port_t             		*ports;
112 		    mach_msg_ool_ports_descriptor_t	*dsc;
113 		    mach_msg_type_number_t   		j;
114 
115 		    /*
116 		     * Destroy port rights carried in the message
117 		     */
118 		    dsc = &saddr->ool_ports;
119 		    ports = (mach_port_t *) dsc->address;
120 		    for (j = 0; j < dsc->count; j++, ports++)  {
121 		        mach_msg_destroy_port(*ports, dsc->disposition);
122 		    }
123 
124 		    /*
125 		     * Destroy memory carried in the message
126 		     */
127 		    if (dsc->deallocate) {
128 		        mach_msg_destroy_memory((vm_offset_t)dsc->address,
129 					dsc->count * sizeof(mach_port_t));
130 		    }
131 		    break;
132 	        }
133 	    }
134 	}
135 #else
136 	vm_offset_t saddr;
137 	vm_offset_t eaddr;
138 
139 	saddr = (vm_offset_t) (msg + 1);
140 	eaddr = (vm_offset_t) msg + msg->msgh_size;
141 
142 	while (saddr < eaddr) {
143 	    mach_msg_type_long_t *type;
144 	    mach_msg_type_name_t name;
145 	    mach_msg_type_size_t size;
146 	    mach_msg_type_number_t number;
147 	    boolean_t is_inline;
148 	    vm_size_t length;
149 	    vm_offset_t addr;
150 
151 	    type = (mach_msg_type_long_t *) saddr;
152 	    is_inline = type->msgtl_header.msgt_inline;
153 	    if (type->msgtl_header.msgt_longform) {
154 		    name = type->msgtl_name;
155 		    size = type->msgtl_size;
156 		    number = type->msgtl_number;
157 		    saddr += sizeof(mach_msg_type_long_t);
158 	    } else {
159 		    name = type->msgtl_header.msgt_name;
160 		    size = type->msgtl_header.msgt_size;
161 		    number = type->msgtl_header.msgt_number;
162 		    saddr += sizeof(mach_msg_type_t);
163 	    }
164 
165 	    /* calculate length of data in bytes, rounding up */
166 	    length = (((((number * size) + 7) >> 3) + sizeof (int) - 1)
167 		      &~ (sizeof (int) - 1));
168 
169 	    addr = is_inline ? saddr : * (vm_offset_t *) saddr;
170 
171 	    if (MACH_MSG_TYPE_PORT_ANY(name)) {
172 		mach_port_t *ports = (mach_port_t *) addr;
173 		mach_msg_type_number_t i;
174 
175 		for (i = 0; i < number; i++)
176 		    mach_msg_destroy_port(*ports++, name);
177 	    }
178 
179 	    if (is_inline) {
180 		/* inline data sizes round up to int boundaries */
181 		saddr += length;
182 	    } else {
183 		mach_msg_destroy_memory(addr, length);
184 		saddr += sizeof(vm_offset_t);
185 	    }
186 	}
187 #endif
188     }
189 }
190 
weak_alias(__mach_msg_destroy,mach_msg_destroy)191 weak_alias (__mach_msg_destroy, mach_msg_destroy)
192 libc_hidden_def (__mach_msg_destroy)
193 
194 static void
195 mach_msg_destroy_port (mach_port_t port, mach_msg_type_name_t type)
196 {
197     if (MACH_PORT_VALID(port)) switch (type) {
198       case MACH_MSG_TYPE_MOVE_SEND:
199       case MACH_MSG_TYPE_MOVE_SEND_ONCE:
200 	/* destroy the send/send-once right */
201 	(void) __mach_port_deallocate(mach_task_self(), port);
202 	break;
203 
204       case MACH_MSG_TYPE_MOVE_RECEIVE:
205 	/* destroy the receive right */
206 	(void) __mach_port_mod_refs(mach_task_self(), port,
207 				    MACH_PORT_RIGHT_RECEIVE, -1);
208 	break;
209 
210       case MACH_MSG_TYPE_MAKE_SEND:
211 	/* create a send right and then destroy it */
212 	(void) __mach_port_insert_right(mach_task_self(), port,
213 					port, MACH_MSG_TYPE_MAKE_SEND);
214 	(void) __mach_port_deallocate(mach_task_self(), port);
215 	break;
216 
217       case MACH_MSG_TYPE_MAKE_SEND_ONCE:
218 	/* create a send-once right and then destroy it */
219 	(void) __mach_port_extract_right(mach_task_self(), port,
220 					 MACH_MSG_TYPE_MAKE_SEND_ONCE,
221 					 &port, &type);
222 	(void) __mach_port_deallocate(mach_task_self(), port);
223 	break;
224     }
225 }
226 
227 static void
mach_msg_destroy_memory(vm_offset_t addr,vm_size_t size)228 mach_msg_destroy_memory (vm_offset_t addr, vm_size_t size)
229 {
230     if (size > 0)
231 	(void) __vm_deallocate(__mach_task_self(), addr, size);
232 }
233