1 | /* Copyright (C) 1993-2022 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 | #ifdef NDR_CHAR_ASCII /* OSF Mach flavors have different names. */ |
70 | # define mig_reply_header_t mig_reply_error_t |
71 | #endif |
72 | |
73 | mach_msg_return_t |
74 | __mach_msg_server_timeout (boolean_t (*demux) (mach_msg_header_t *request, |
75 | mach_msg_header_t *reply), |
76 | mach_msg_size_t max_size, |
77 | mach_port_t rcv_name, |
78 | mach_msg_option_t option, |
79 | mach_msg_timeout_t timeout) |
80 | { |
81 | mig_reply_header_t *request, *reply; |
82 | mach_msg_return_t mr; |
83 | |
84 | if (max_size == 0) |
85 | { |
86 | #ifdef MACH_RCV_LARGE |
87 | option |= MACH_RCV_LARGE; |
88 | max_size = 2 * __vm_page_size; /* Generic. Good? XXX */ |
89 | #else |
90 | max_size = 4 * __vm_page_size; /* XXX */ |
91 | #endif |
92 | } |
93 | |
94 | request = __alloca (max_size); |
95 | reply = __alloca (max_size); |
96 | |
97 | while (1) |
98 | { |
99 | get_request: |
100 | mr = __mach_msg (&request->Head, MACH_RCV_MSG|option, |
101 | 0, max_size, rcv_name, |
102 | timeout, MACH_PORT_NULL); |
103 | while (mr == MACH_MSG_SUCCESS) |
104 | { |
105 | /* We have a request message. |
106 | Pass it to DEMUX for processing. */ |
107 | |
108 | (void) (*demux) (&request->Head, &reply->Head); |
109 | assert (reply->Head.msgh_size <= max_size); |
110 | |
111 | switch (reply->RetCode) |
112 | { |
113 | case KERN_SUCCESS: |
114 | /* Hunky dory. */ |
115 | break; |
116 | |
117 | case MIG_NO_REPLY: |
118 | /* The server function wanted no reply sent. |
119 | Loop for another request. */ |
120 | goto get_request; |
121 | |
122 | default: |
123 | /* Some error; destroy the request message to release any |
124 | port rights or VM it holds. Don't destroy the reply port |
125 | right, so we can send an error message. */ |
126 | request->Head.msgh_remote_port = MACH_PORT_NULL; |
127 | __mach_msg_destroy (&request->Head); |
128 | break; |
129 | } |
130 | |
131 | if (reply->Head.msgh_remote_port == MACH_PORT_NULL) |
132 | { |
133 | /* No reply port, so destroy the reply. */ |
134 | if (reply->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX) |
135 | __mach_msg_destroy (&reply->Head); |
136 | goto get_request; |
137 | } |
138 | |
139 | /* Send the reply and the get next request. */ |
140 | |
141 | { |
142 | /* Swap the request and reply buffers. mach_msg will read the |
143 | reply message from the buffer we pass and write the new |
144 | request message to the same buffer. */ |
145 | void *tmp = request; |
146 | request = reply; |
147 | reply = tmp; |
148 | } |
149 | |
150 | mr = __mach_msg (&request->Head, |
151 | MACH_SEND_MSG|MACH_RCV_MSG|option, |
152 | request->Head.msgh_size, max_size, rcv_name, |
153 | timeout, MACH_PORT_NULL); |
154 | } |
155 | |
156 | /* A message error occurred. */ |
157 | |
158 | switch (mr) |
159 | { |
160 | case MACH_RCV_TOO_LARGE: |
161 | #ifdef MACH_RCV_LARGE |
162 | /* The request message is larger than MAX_SIZE, and has not |
163 | been dequeued. The message header has the actual size of |
164 | the message. We recurse here in hopes that the compiler |
165 | will optimize the tail-call and allocate some more stack |
166 | space instead of way too much. */ |
167 | return __mach_msg_server_timeout (demux, request->Head.msgh_size, |
168 | rcv_name, option, timeout); |
169 | #else |
170 | /* XXX the kernel has destroyed the msg */ |
171 | break; |
172 | #endif |
173 | |
174 | case MACH_SEND_INVALID_DEST: |
175 | /* The reply can't be delivered, so destroy it. This error |
176 | indicates only that the requester went away, so we |
177 | continue and get the next request. */ |
178 | __mach_msg_destroy (&request->Head); |
179 | break; |
180 | |
181 | default: |
182 | /* Some other form of lossage; return to caller. */ |
183 | return mr; |
184 | } |
185 | } |
186 | } |
187 | weak_alias (__mach_msg_server_timeout, mach_msg_server_timeout) |
188 | |
189 | mach_msg_return_t |
190 | __mach_msg_server (boolean_t (*demux) (mach_msg_header_t *in, |
191 | mach_msg_header_t *out), |
192 | mach_msg_size_t max_size, |
193 | mach_port_t rcv_name) |
194 | { |
195 | return __mach_msg_server_timeout (demux, max_size, rcv_name, |
196 | MACH_MSG_OPTION_NONE, |
197 | MACH_MSG_TIMEOUT_NONE); |
198 | } |
199 | weak_alias (__mach_msg_server, mach_msg_server) |
200 | |