mach/msg-destroy.c

   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
  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
 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
 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 }