1 | /* Copyright (C) 1993-2024 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. |
3 | |
4 | The GNU C Library is free software; you can redistribute it and/or |
5 | modify it under the terms of the GNU Lesser General Public |
6 | License as published by the Free Software Foundation; either |
7 | version 2.1 of the License, or (at your option) any later version. |
8 | |
9 | The GNU C Library is distributed in the hope that it will be useful, |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
12 | Lesser General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU Lesser General Public |
15 | License along with the GNU C Library; if not, see |
16 | <https://www.gnu.org/licenses/>. */ |
17 | |
18 | /* Based on CMU's mach_msg_server.c revision 2.4 of 91/05/14, and thus |
19 | under the following copyright. Rewritten by Roland McGrath (FSF) |
20 | 93/12/06 to use stack space instead of malloc, and to handle |
21 | large messages with MACH_RCV_LARGE. */ |
22 | |
23 | /* |
24 | * Mach Operating System |
25 | * Copyright (c) 1991,1990 Carnegie Mellon University |
26 | * All Rights Reserved. |
27 | * |
28 | * Permission to use, copy, modify and distribute this software and its |
29 | * documentation is hereby granted, provided that both the copyright |
30 | * notice and this permission notice appear in all copies of the |
31 | * software, derivative works or modified versions, and any portions |
32 | * thereof, and that both notices appear in supporting documentation. |
33 | * |
34 | * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" |
35 | * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR |
36 | * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. |
37 | * |
38 | * Carnegie Mellon requests users of this software to return to |
39 | * |
40 | * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU |
41 | * School of Computer Science |
42 | * Carnegie Mellon University |
43 | * Pittsburgh PA 15213-3890 |
44 | * |
45 | * any improvements or extensions that they make and grant Carnegie Mellon |
46 | * the rights to redistribute these changes. |
47 | */ |
48 | /* |
49 | * (pre-GNU) HISTORY |
50 | * |
51 | * Revision 2.4 91/05/14 17:53:22 mrt |
52 | * Correcting copyright |
53 | * |
54 | * Revision 2.3 91/02/14 14:17:47 mrt |
55 | * Added new Mach copyright |
56 | * [91/02/13 12:44:20 mrt] |
57 | * |
58 | * Revision 2.2 90/08/06 17:23:58 rpd |
59 | * Created. |
60 | * |
61 | */ |
62 | |
63 | |
64 | #include <mach.h> |
65 | #include <mach/mig_errors.h> |
66 | #include <stdlib.h> /* For malloc and free. */ |
67 | #include <assert.h> |
68 | |
69 | mach_msg_return_t |
70 | __mach_msg_server_timeout (boolean_t (*demux) (mach_msg_header_t *request, |
71 | mach_msg_header_t *reply), |
72 | mach_msg_size_t max_size, |
73 | mach_port_t rcv_name, |
74 | mach_msg_option_t option, |
75 | mach_msg_timeout_t timeout) |
76 | { |
77 | mig_reply_header_t *request, *reply; |
78 | mach_msg_return_t mr; |
79 | |
80 | if (max_size == 0) |
81 | { |
82 | #ifdef MACH_RCV_LARGE |
83 | option |= MACH_RCV_LARGE; |
84 | max_size = 2 * __vm_page_size; /* Generic. Good? XXX */ |
85 | #else |
86 | max_size = 4 * __vm_page_size; /* XXX */ |
87 | #endif |
88 | } |
89 | |
90 | request = __alloca (max_size); |
91 | reply = __alloca (max_size); |
92 | |
93 | while (1) |
94 | { |
95 | get_request: |
96 | mr = __mach_msg (&request->Head, MACH_RCV_MSG|option, |
97 | 0, max_size, rcv_name, |
98 | timeout, MACH_PORT_NULL); |
99 | while (mr == MACH_MSG_SUCCESS) |
100 | { |
101 | /* We have a request message. |
102 | Pass it to DEMUX for processing. */ |
103 | |
104 | (void) (*demux) (&request->Head, &reply->Head); |
105 | assert (reply->Head.msgh_size <= max_size); |
106 | |
107 | switch (reply->RetCode) |
108 | { |
109 | case KERN_SUCCESS: |
110 | /* Hunky dory. */ |
111 | break; |
112 | |
113 | case MIG_NO_REPLY: |
114 | /* The server function wanted no reply sent. |
115 | Loop for another request. */ |
116 | goto get_request; |
117 | |
118 | default: |
119 | /* Some error; destroy the request message to release any |
120 | port rights or VM it holds. Don't destroy the reply port |
121 | right, so we can send an error message. */ |
122 | request->Head.msgh_remote_port = MACH_PORT_NULL; |
123 | __mach_msg_destroy (&request->Head); |
124 | break; |
125 | } |
126 | |
127 | if (reply->Head.msgh_remote_port == MACH_PORT_NULL) |
128 | { |
129 | /* No reply port, so destroy the reply. */ |
130 | if (reply->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX) |
131 | __mach_msg_destroy (&reply->Head); |
132 | goto get_request; |
133 | } |
134 | |
135 | /* Send the reply and the get next request. */ |
136 | |
137 | { |
138 | /* Swap the request and reply buffers. mach_msg will read the |
139 | reply message from the buffer we pass and write the new |
140 | request message to the same buffer. */ |
141 | void *tmp = request; |
142 | request = reply; |
143 | reply = tmp; |
144 | } |
145 | |
146 | mr = __mach_msg (&request->Head, |
147 | MACH_SEND_MSG|MACH_RCV_MSG|option, |
148 | request->Head.msgh_size, max_size, rcv_name, |
149 | timeout, MACH_PORT_NULL); |
150 | } |
151 | |
152 | /* A message error occurred. */ |
153 | |
154 | switch (mr) |
155 | { |
156 | case MACH_RCV_TOO_LARGE: |
157 | #ifdef MACH_RCV_LARGE |
158 | /* The request message is larger than MAX_SIZE, and has not |
159 | been dequeued. The message header has the actual size of |
160 | the message. We recurse here in hopes that the compiler |
161 | will optimize the tail-call and allocate some more stack |
162 | space instead of way too much. */ |
163 | return __mach_msg_server_timeout (demux, request->Head.msgh_size, |
164 | rcv_name, option, timeout); |
165 | #else |
166 | /* XXX the kernel has destroyed the msg */ |
167 | break; |
168 | #endif |
169 | |
170 | case MACH_SEND_INVALID_DEST: |
171 | /* The reply can't be delivered, so destroy it. This error |
172 | indicates only that the requester went away, so we |
173 | continue and get the next request. */ |
174 | __mach_msg_destroy (&request->Head); |
175 | break; |
176 | |
177 | default: |
178 | /* Some other form of lossage; return to caller. */ |
179 | return mr; |
180 | } |
181 | } |
182 | } |
183 | weak_alias (__mach_msg_server_timeout, mach_msg_server_timeout) |
184 | |
185 | mach_msg_return_t |
186 | __mach_msg_server (boolean_t (*demux) (mach_msg_header_t *in, |
187 | mach_msg_header_t *out), |
188 | mach_msg_size_t max_size, |
189 | mach_port_t rcv_name) |
190 | { |
191 | return __mach_msg_server_timeout (demux, max_size, rcv_name, |
192 | MACH_MSG_OPTION_NONE, |
193 | MACH_MSG_TIMEOUT_NONE); |
194 | } |
195 | weak_alias (__mach_msg_server, mach_msg_server) |
196 | |