xref: /xnu-10002.81.5/osfmk/kern/ipc_misc.c (revision 5e3eaea39dcf651e66cb99ba7d70e32cc4a99587)
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 <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
fileport_alloc(struct fileglob * fg)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 *
fileport_port_to_fileglob(ipc_port_t port)75 fileport_port_to_fileglob(ipc_port_t port)
76 {
77 	if (IP_VALID(port)) {
78 		return ipc_kobject_get_stable(port, IKOT_FILEPORT);
79 	}
80 	return NULL;
81 }
82 
83 
84 /*
85  * fileport_no_senders
86  *
87  * Description: Handle a no-senders notification for a fileport.  Unless
88  *              the message is spoofed, destroys the port and releases
89  *              its reference on the fileglob.
90  *
91  * Parameters: msg		A Mach no-senders notification message.
92  */
93 static void
fileport_no_senders(ipc_port_t port,mach_port_mscount_t mscount)94 fileport_no_senders(ipc_port_t port, mach_port_mscount_t mscount)
95 {
96 	struct fileglob *fg;
97 
98 	fg = ipc_kobject_dealloc_port(port, mscount, IKOT_FILEPORT);
99 
100 	fileport_releasefg(fg);
101 }
102 
103 IPC_KOBJECT_DEFINE(IKOT_FILEPORT,
104     .iko_op_stable     = true,
105     .iko_op_no_senders = fileport_no_senders);
106 
107 /*
108  * fileport_invoke
109  *
110  * Description: Invoke a function with the fileglob underlying the fileport.
111  *		Returns the error code related to the fileglob lookup.
112  *
113  * Parameters:	task		The target task
114  *		action		The function to invoke with the fileglob
115  *		arg		Anonymous pointer to caller state
116  *		rval		The value returned from calling 'action'
117  */
118 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)119 fileport_invoke(task_t task, mach_port_name_t name,
120     int (*action)(mach_port_name_t, struct fileglob *, void *),
121     void *arg, int *rval)
122 {
123 	kern_return_t kr;
124 	ipc_port_t fileport;
125 	struct fileglob *fg;
126 
127 	kr = ipc_object_copyin(task->itk_space, name,
128 	    MACH_MSG_TYPE_COPY_SEND, (ipc_object_t *)&fileport, 0, NULL,
129 	    IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND);
130 	if (kr != KERN_SUCCESS) {
131 		return kr;
132 	}
133 
134 	if ((fg = fileport_port_to_fileglob(fileport)) != NULL) {
135 		*rval = (*action)(name, fg, arg);
136 	} else {
137 		kr = KERN_FAILURE;
138 	}
139 	ipc_port_release_send(fileport);
140 	return kr;
141 }
142 
143 /*
144  * fileport_walk
145  *
146  * Description: Invoke the action function on every fileport in the task.
147  *
148  * Parameters:  task		The target task
149  *		countp		Returns how many ports were found
150  *		action		The function to invoke on each fileport
151  */
152 kern_return_t
153 fileport_walk(task_t task, size_t *countp,
154     bool (^cb)(size_t i, mach_port_name_t, struct fileglob *))
155 {
156 	const uint32_t BATCH_SIZE = 4 << 10;
157 	ipc_space_t space = task->itk_space;
158 	ipc_entry_table_t table;
159 	ipc_entry_num_t index;
160 	ipc_entry_t entry;
161 	size_t count = 0;
162 
163 	is_read_lock(space);
164 	if (!is_active(space)) {
165 		is_read_unlock(space);
166 		return KERN_INVALID_TASK;
167 	}
168 
169 	table = is_active_table(space);
170 	entry = ipc_entry_table_base(table);
171 
172 	/* skip the first element which is not a real entry */
173 	index = 1;
174 	entry = ipc_entry_table_next_elem(table, entry);
175 
176 	for (;;) {
177 		ipc_entry_bits_t bits = entry->ie_bits;
178 		ipc_object_t io = entry->ie_object;
179 		mach_port_name_t name;
180 		struct fileglob *fg;
181 
182 		if (IE_BITS_TYPE(bits) & MACH_PORT_TYPE_SEND) {
183 			name = MACH_PORT_MAKE(index, IE_BITS_GEN(bits));
184 			fg   = fileport_port_to_fileglob(ip_object_to_port(io));
185 
186 			if (fg) {
187 				if (cb && !cb(count, name, fg)) {
188 					cb = NULL;
189 					if (countp == NULL) {
190 						break;
191 					}
192 				}
193 				count++;
194 			}
195 		}
196 
197 		index++;
198 		entry = ipc_entry_table_next_elem(table, entry);
199 		if (!entry) {
200 			break;
201 		}
202 		if (index % BATCH_SIZE == 0) {
203 			/*
204 			 * Give the system some breathing room,
205 			 * validate that the space is still valid,
206 			 * and reload the pointer and length.
207 			 */
208 			is_read_unlock(space);
209 			is_read_lock(space);
210 			if (!is_active(space)) {
211 				is_read_unlock(space);
212 				return KERN_INVALID_TASK;
213 			}
214 
215 			table = is_active_table(space);
216 			entry = ipc_entry_table_get_nocheck(table, index);
217 		}
218 	}
219 
220 	is_read_unlock(space);
221 
222 	if (countp) {
223 		*countp = count;
224 	}
225 
226 	return KERN_SUCCESS;
227 }
228