xref: /xnu-12377.41.6/osfmk/kern/ipc_misc.c (revision bbb1b6f9e71b8cdde6e5cd6f4841f207dee3d828)
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,
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23  * Please see the License for the specific language governing rights and
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27  */
28 #include <mach/mach_types.h>
29 #include <mach/notify.h>
30 #include <ipc/ipc_port.h>
31 #include <ipc/ipc_space.h>
32 #include <kern/ipc_kobject.h>
33 #include <kern/ipc_misc.h>
34 
35 #include <mach/mach_port.h>
36 #include <mach/vm_map.h>
37 #include <vm/vm_map.h>
38 #include <vm/vm_kern.h>
39 
40 extern void fileport_releasefg(struct fileglob *);
41 
42 /*
43  * fileport_alloc
44  *
45  * Description: Obtain a send right for the given fileglob, which must be
46  *		referenced.
47  *
48  * Parameters:  fg		A fileglob.
49  *
50  * Returns:     Port of type IKOT_FILEPORT with fileglob set as its kobject.
51  *              Port is returned with a send right.
52  */
53 ipc_port_t
fileport_alloc(struct fileglob * fg)54 fileport_alloc(struct fileglob *fg)
55 {
56 	return ipc_kobject_alloc_port(fg, IKOT_FILEPORT,
57 	           IPC_KOBJECT_ALLOC_MAKE_SEND);
58 }
59 
60 
61 /*
62  * fileport_get_fileglob
63  *
64  * Description: Obtain the fileglob associated with a given port.
65  *
66  * Parameters: port		A Mach port of type IKOT_FILEPORT.
67  *
68  * Returns:    NULL		The given Mach port did not reference a
69  *				fileglob.
70  *	       !NULL		The fileglob that is associated with the
71  *				Mach port.
72  *
73  * Notes: The caller must have a reference on the fileport.
74  */
75 struct fileglob *
fileport_port_to_fileglob(ipc_port_t port)76 fileport_port_to_fileglob(ipc_port_t port)
77 {
78 	if (IP_VALID(port)) {
79 		return ipc_kobject_get_stable(port, IKOT_FILEPORT);
80 	}
81 	return NULL;
82 }
83 
84 
85 /*
86  * fileport_no_senders
87  *
88  * Description: Handle a no-senders notification for a fileport.  Unless
89  *              the message is spoofed, destroys the port and releases
90  *              its reference on the fileglob.
91  *
92  * Parameters: msg		A Mach no-senders notification message.
93  */
94 static void
fileport_no_senders(ipc_port_t port,mach_port_mscount_t mscount)95 fileport_no_senders(ipc_port_t port, mach_port_mscount_t mscount)
96 {
97 	struct fileglob *fg;
98 
99 	fg = ipc_kobject_dealloc_port(port, mscount, IKOT_FILEPORT);
100 
101 	fileport_releasefg(fg);
102 }
103 
104 IPC_KOBJECT_DEFINE(IKOT_FILEPORT,
105     .iko_op_movable_send = true,
106     .iko_op_stable     = true,
107     .iko_op_no_senders = fileport_no_senders);
108 
109 /*
110  * fileport_invoke
111  *
112  * Description: Invoke a function with the fileglob underlying the fileport.
113  *		Returns the error code related to the fileglob lookup.
114  *
115  * Parameters:	task		The target task
116  *		action		The function to invoke with the fileglob
117  *		arg		Anonymous pointer to caller state
118  *		rval		The value returned from calling 'action'
119  */
120 kern_return_t
fileport_invoke(task_t task,mach_port_name_t name,int (* action)(mach_port_name_t,struct fileglob *,void *),void * arg,int * rval)121 fileport_invoke(task_t task, mach_port_name_t name,
122     int (*action)(mach_port_name_t, struct fileglob *, void *),
123     void *arg, int *rval)
124 {
125 	kern_return_t kr;
126 	ipc_port_t fileport;
127 	struct fileglob *fg;
128 
129 	kr = ipc_typed_port_copyin_send(task->itk_space, name,
130 	    IKOT_FILEPORT, &fileport);
131 	if (kr != KERN_SUCCESS) {
132 		return kr;
133 	}
134 
135 	if ((fg = fileport_port_to_fileglob(fileport)) != NULL) {
136 		*rval = (*action)(name, fg, arg);
137 	} else {
138 		kr = KERN_FAILURE;
139 	}
140 	ipc_typed_port_release_send(fileport, IKOT_FILEPORT);
141 	return kr;
142 }
143 
144 /*
145  * fileport_walk
146  *
147  * Description: Invoke the action function on every fileport in the task.
148  *
149  * Parameters:  task		The target task
150  *		countp		Returns how many ports were found
151  *		action		The function to invoke on each fileport
152  */
153 kern_return_t
154 fileport_walk(task_t task, size_t *countp,
155     bool (^cb)(size_t i, mach_port_name_t, struct fileglob *))
156 {
157 	const uint32_t BATCH_SIZE = 4 << 10;
158 	ipc_space_t space = task->itk_space;
159 	ipc_entry_table_t table;
160 	ipc_entry_num_t index;
161 	ipc_entry_t entry;
162 	size_t count = 0;
163 
164 	is_read_lock(space);
165 	if (!is_active(space)) {
166 		is_read_unlock(space);
167 		return KERN_INVALID_TASK;
168 	}
169 
170 	table = is_active_table(space);
171 	entry = ipc_entry_table_base(table);
172 
173 	/* skip the first element which is not a real entry */
174 	index = 1;
175 	entry = ipc_entry_table_next_elem(table, entry);
176 
177 	for (;;) {
178 		ipc_entry_bits_t bits = entry->ie_bits;
179 		mach_port_name_t name;
180 		struct fileglob *fg;
181 
182 		if (IE_BITS_TYPE(bits) & MACH_PORT_TYPE_SEND) {
183 			ipc_port_t port = entry->ie_port;
184 
185 			name = MACH_PORT_MAKE(index, IE_BITS_GEN(bits));
186 			fg   = fileport_port_to_fileglob(port);
187 
188 			if (fg) {
189 				if (cb && !cb(count, name, fg)) {
190 					cb = NULL;
191 					if (countp == NULL) {
192 						break;
193 					}
194 				}
195 				count++;
196 			}
197 		}
198 
199 		index++;
200 		entry = ipc_entry_table_next_elem(table, entry);
201 		if (!entry) {
202 			break;
203 		}
204 		if (index % BATCH_SIZE == 0) {
205 			/*
206 			 * Give the system some breathing room,
207 			 * validate that the space is still valid,
208 			 * and reload the pointer and length.
209 			 */
210 			is_read_unlock(space);
211 			is_read_lock(space);
212 			if (!is_active(space)) {
213 				is_read_unlock(space);
214 				return KERN_INVALID_TASK;
215 			}
216 
217 			table = is_active_table(space);
218 			entry = ipc_entry_table_get_nocheck(table, index);
219 		}
220 	}
221 
222 	is_read_unlock(space);
223 
224 	if (countp) {
225 		*countp = count;
226 	}
227 
228 	return KERN_SUCCESS;
229 }
230