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         ipc_port_t fileport;
  56         ipc_port_t sendport;
  57         ipc_port_t notifyport;
  58
  59         fileport = ipc_port_alloc_kernel();
  60         if (fileport == IP_NULL) {
  61                 goto out;
  62         }
  63
  64         ipc_kobject_set(fileport, (ipc_kobject_t)fg, IKOT_FILEPORT);
  65         ip_lock(fileport); /* unlocked by ipc_port_nsrequest */
  66         notifyport = ipc_port_make_sonce_locked(fileport);
  67         ipc_port_nsrequest(fileport, 1, notifyport, &notifyport);
  68
  69         sendport = ipc_port_make_send(fileport);
  70         if (!IP_VALID(sendport)) {
  71                 panic("Couldn't allocate send right for fileport!\n");
  72         }
  73
  74 out:
  75         return fileport;
  76 }
  77
  78
  79 /*
  80  * fileport_get_fileglob
  81  *
  82  * Description: Obtain the fileglob associated with a given port.
  83  *
  84  * Parameters: port             A Mach port of type IKOT_FILEPORT.
  85  *
  86  * Returns:    NULL             The given Mach port did not reference a
  87  *                              fileglob.
  88  *             !NULL            The fileglob that is associated with the
  89  *                              Mach port.
  90  *
  91  * Notes: The caller must have a reference on the fileport.
  92  */
  93 struct fileglob *
  94 fileport_port_to_fileglob(ipc_port_t port)
  95 {
  96         struct fileglob *fg = NULL;
  97
  98         if (!IP_VALID(port)) {
  99                 return NULL;
 100         }
 101
 102         ip_lock(port);
 103         if (ip_active(port) && IKOT_FILEPORT == ip_kotype(port)) {
 104                 fg = (void *)port->ip_kobject;
 105         }
 106         ip_unlock(port);
 107
 108         return fg;
 109 }
 110
 111
 112 /*
 113  * fileport_notify
 114  *
 115  * Description: Handle a no-senders notification for a fileport.  Unless
 116  *              the message is spoofed, destroys the port and releases
 117  *              its reference on the fileglob.
 118  *
 119  * Parameters: msg              A Mach no-senders notification message.
 120  */
 121 void
 122 fileport_notify(mach_msg_header_t *msg)
 123 {
 124         mach_no_senders_notification_t *notification = (void *)msg;
 125         ipc_port_t port = notification->not_header.msgh_remote_port;
 126         struct fileglob *fg = NULL;
 127
 128         if (!IP_VALID(port)) {
 129                 panic("Invalid port passed to fileport_notify()\n");
 130         }
 131
 132         ip_lock(port);
 133
 134         fg = (struct fileglob *)port->ip_kobject;
 135
 136         if (!ip_active(port)) {
 137                 panic("Inactive port passed to fileport_notify()\n");
 138         }
 139         if (ip_kotype(port) != IKOT_FILEPORT) {
 140                 panic("Port of type other than IKOT_FILEPORT passed to fileport_notify()\n");
 141         }
 142         if (fg == NULL) {
 143                 panic("fileport without an assocated fileglob\n");
 144         }
 145
 146         if (port->ip_srights == 0) {
 147                 ip_unlock(port);
 148
 149                 fileport_releasefg(fg);
 150                 ipc_port_dealloc_kernel(port);
 151         } else {
 152                 ip_unlock(port);
 153         }
 154 }
 155
 156 /*
 157  * fileport_invoke
 158  *
 159  * Description: Invoke a function with the fileglob underlying the fileport.
 160  *              Returns the error code related to the fileglob lookup.
 161  *
 162  * Parameters:  task            The target task
 163  *              action          The function to invoke with the fileglob
 164  *              arg             Anonymous pointer to caller state
 165  *              rval            The value returned from calling 'action'
 166  */
 167 kern_return_t
 168 fileport_invoke(task_t task, mach_port_name_t name,
 169     int (*action)(mach_port_name_t, struct fileglob *, void *),
 170     void *arg, int *rval)
 171 {
 172         kern_return_t kr;
 173         ipc_port_t fileport;
 174         struct fileglob *fg;
 175
 176         kr = ipc_object_copyin(task->itk_space, name,
 177             MACH_MSG_TYPE_COPY_SEND, (ipc_object_t *)&fileport);
 178         if (kr != KERN_SUCCESS) {
 179                 return kr;
 180         }
 181
 182         if ((fg = fileport_port_to_fileglob(fileport)) != NULL) {
 183                 *rval = (*action)(name, fg, arg);
 184         } else {
 185                 kr = KERN_FAILURE;
 186         }
 187         ipc_port_release_send(fileport);
 188         return kr;
 189 }
 190
 191 /*
 192  * fileport_walk
 193  *
 194  * Description: Invoke the action function on every fileport in the task.
 195  *
 196  *              This could be more efficient if we refactored mach_port_names()
 197  *              so that (a) it didn't compute the type information unless asked
 198  *              and (b) it could be asked to -not- unwire/copyout the memory
 199  *              and (c) if we could ask for port names by kobject type. Not
 200  *              clear that it's worth all that complexity, though.
 201  *
 202  * Parameters:  task            The target task
 203  *              action          The function to invoke on each fileport
 204  *              arg             Anonymous pointer to caller state.
 205  */
 206 kern_return_t
 207 fileport_walk(task_t task,
 208     int (*action)(mach_port_name_t, struct fileglob *, void *arg),
 209     void *arg)
 210 {
 211         mach_port_name_t *names;
 212         mach_msg_type_number_t ncnt, tcnt;
 213         vm_map_copy_t map_copy_names, map_copy_types;
 214         vm_map_address_t map_names;
 215         kern_return_t kr;
 216         uint_t i;
 217         int rval;
 218
 219         /*
 220          * mach_port_names returns the 'name' and 'types' in copied-in
 221          * form.  Discard 'types' immediately, then copyout 'names'
 222          * back into the kernel before walking the array.
 223          */
 224
 225         kr = mach_port_names(task->itk_space,
 226             (mach_port_name_t **)&map_copy_names, &ncnt,
 227             (mach_port_type_t **)&map_copy_types, &tcnt);
 228         if (kr != KERN_SUCCESS) {
 229                 return kr;
 230         }
 231
 232         vm_map_copy_discard(map_copy_types);
 233
 234         kr = vm_map_copyout(ipc_kernel_map, &map_names, map_copy_names);
 235         if (kr != KERN_SUCCESS) {
 236                 vm_map_copy_discard(map_copy_names);
 237                 return kr;
 238         }
 239         names = (mach_port_name_t *)(uintptr_t)map_names;
 240
 241         for (rval = 0, i = 0; i < ncnt; i++) {
 242                 if (fileport_invoke(task, names[i], action, arg,
 243                     &rval) == KERN_SUCCESS && -1 == rval) {
 244                         break;          /* early termination clause */
 245                 }
 246         }
 247         vm_deallocate(ipc_kernel_map,
 248             (vm_address_t)names, ncnt * sizeof(*names));
 249         return KERN_SUCCESS;
 250 }