osfmk/kern/ipc_misc.c

   1 /*
   2  * Copyright (c) 2008, 2010 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/ipc_misc.h>
  33
  34 #include <mach/mach_port.h>
  35 #include <mach/vm_map.h>
  36 #include <vm/vm_map.h>
  37 #include <vm/vm_kern.h>
  38
  39 extern void fileport_releasefg(struct fileglob *);
  40
  41 /*
  42  * fileport_alloc
  43  *
  44  * Description: Obtain a send right for the given fileglob, which must be
  45  *              referenced.
  46  *
  47  * Parameters:  fg              A fileglob.
  48  *
  49  * Returns:     Port of type IKOT_FILEPORT with fileglob set as its kobject.
  50  *              Port is returned with a send right.
  51  */
  52 ipc_port_t
  53 fileport_alloc(struct fileglob *fg)
  54 {
  55         return ipc_kobject_alloc_port((ipc_kobject_t)fg, IKOT_FILEPORT,
  56                    IPC_KOBJECT_ALLOC_MAKE_SEND | IPC_KOBJECT_ALLOC_NSREQUEST);
  57 }
  58
  59
  60 /*
  61  * fileport_get_fileglob
  62  *
  63  * Description: Obtain the fileglob associated with a given port.
  64  *
  65  * Parameters: port             A Mach port of type IKOT_FILEPORT.
  66  *
  67  * Returns:    NULL             The given Mach port did not reference a
  68  *                              fileglob.
  69  *             !NULL            The fileglob that is associated with the
  70  *                              Mach port.
  71  *
  72  * Notes: The caller must have a reference on the fileport.
  73  */
  74 struct fileglob *
  75 fileport_port_to_fileglob(ipc_port_t port)
  76 {
  77         struct fileglob *fg = NULL;
  78
  79         if (!IP_VALID(port)) {
  80                 return NULL;
  81         }
  82
  83         ip_lock(port);
  84         if (ip_active(port) && IKOT_FILEPORT == ip_kotype(port)) {
  85                 fg = (void *) ip_get_kobject(port);
  86         }
  87         ip_unlock(port);
  88
  89         return fg;
  90 }
  91
  92
  93 /*
  94  * fileport_notify
  95  *
  96  * Description: Handle a no-senders notification for a fileport.  Unless
  97  *              the message is spoofed, destroys the port and releases
  98  *              its reference on the fileglob.
  99  *
 100  * Parameters: msg              A Mach no-senders notification message.
 101  */
 102 void
 103 fileport_notify(mach_msg_header_t *msg)
 104 {
 105         mach_no_senders_notification_t *notification = (void *)msg;
 106         ipc_port_t port = notification->not_header.msgh_remote_port;
 107         struct fileglob *fg = NULL;
 108
 109         if (!IP_VALID(port)) {
 110                 panic("Invalid port passed to fileport_notify()\n");
 111         }
 112
 113         ip_lock(port);
 114
 115         fg = (struct fileglob *) ip_get_kobject(port);
 116
 117         if (!ip_active(port)) {
 118                 panic("Inactive port passed to fileport_notify()\n");
 119         }
 120         if (ip_kotype(port) != IKOT_FILEPORT) {
 121                 panic("Port of type other than IKOT_FILEPORT passed to fileport_notify()\n");
 122         }
 123         if (fg == NULL) {
 124                 panic("fileport without an assocated fileglob\n");
 125         }
 126
 127         if (port->ip_srights == 0) {
 128                 ip_unlock(port);
 129
 130                 fileport_releasefg(fg);
 131                 ipc_port_dealloc_kernel(port);
 132         } else {
 133                 ip_unlock(port);
 134         }
 135 }
 136
 137 /*
 138  * fileport_invoke
 139  *
 140  * Description: Invoke a function with the fileglob underlying the fileport.
 141  *              Returns the error code related to the fileglob lookup.
 142  *
 143  * Parameters:  task            The target task
 144  *              action          The function to invoke with the fileglob
 145  *              arg             Anonymous pointer to caller state
 146  *              rval            The value returned from calling 'action'
 147  */
 148 kern_return_t
 149 fileport_invoke(task_t task, mach_port_name_t name,
 150     int (*action)(mach_port_name_t, struct fileglob *, void *),
 151     void *arg, int *rval)
 152 {
 153         kern_return_t kr;
 154         ipc_port_t fileport;
 155         struct fileglob *fg;
 156
 157         kr = ipc_object_copyin(task->itk_space, name,
 158             MACH_MSG_TYPE_COPY_SEND, (ipc_object_t *)&fileport, 0, NULL,
 159             IPC_KMSG_FLAGS_ALLOW_IMMOVABLE_SEND);
 160         if (kr != KERN_SUCCESS) {
 161                 return kr;
 162         }
 163
 164         if ((fg = fileport_port_to_fileglob(fileport)) != NULL) {
 165                 *rval = (*action)(name, fg, arg);
 166         } else {
 167                 kr = KERN_FAILURE;
 168         }
 169         ipc_port_release_send(fileport);
 170         return kr;
 171 }
 172
 173 /*
 174  * fileport_walk
 175  *
 176  * Description: Invoke the action function on every fileport in the task.
 177  *
 178  *              This could be more efficient if we refactored mach_port_names()
 179  *              so that (a) it didn't compute the type information unless asked
 180  *              and (b) it could be asked to -not- unwire/copyout the memory
 181  *              and (c) if we could ask for port names by kobject type. Not
 182  *              clear that it's worth all that complexity, though.
 183  *
 184  * Parameters:  task            The target task
 185  *              action          The function to invoke on each fileport
 186  *              arg             Anonymous pointer to caller state.
 187  */
 188 kern_return_t
 189 fileport_walk(task_t task,
 190     int (*action)(mach_port_name_t, struct fileglob *, void *arg),
 191     void *arg)
 192 {
 193         mach_port_name_t *names;
 194         mach_msg_type_number_t ncnt, tcnt;
 195         vm_map_copy_t map_copy_names, map_copy_types;
 196         vm_map_address_t map_names;
 197         kern_return_t kr;
 198         uint_t i;
 199         int rval;
 200
 201         /*
 202          * mach_port_names returns the 'name' and 'types' in copied-in
 203          * form.  Discard 'types' immediately, then copyout 'names'
 204          * back into the kernel before walking the array.
 205          */
 206
 207         kr = mach_port_names(task->itk_space,
 208             (mach_port_name_t **)&map_copy_names, &ncnt,
 209             (mach_port_type_t **)&map_copy_types, &tcnt);
 210         if (kr != KERN_SUCCESS) {
 211                 return kr;
 212         }
 213
 214         vm_map_copy_discard(map_copy_types);
 215
 216         kr = vm_map_copyout(ipc_kernel_map, &map_names, map_copy_names);
 217         if (kr != KERN_SUCCESS) {
 218                 vm_map_copy_discard(map_copy_names);
 219                 return kr;
 220         }
 221         names = (mach_port_name_t *)(uintptr_t)map_names;
 222
 223         for (rval = 0, i = 0; i < ncnt; i++) {
 224                 if (fileport_invoke(task, names[i], action, arg,
 225                     &rval) == KERN_SUCCESS && -1 == rval) {
 226                         break;          /* early termination clause */
 227                 }
 228         }
 229         vm_deallocate(ipc_kernel_map,
 230             (vm_address_t)names, ncnt * sizeof(*names));
 231         return KERN_SUCCESS;
 232 }