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_OBJECT_COPYIN_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  }