Merge tag 'bsd-user-syscall-2022q2b-pull-request' of ssh://github.com/qemu-bsd-user...
[qemu.git] / io / channel-buffer.c
1 /*
2 * QEMU I/O channels memory buffer driver
3 *
4 * Copyright (c) 2015 Red Hat, Inc.
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18 *
19 */
20
21 #include "qemu/osdep.h"
22 #include "io/channel-buffer.h"
23 #include "io/channel-watch.h"
24 #include "qemu/module.h"
25 #include "qemu/sockets.h"
26 #include "trace.h"
27
28 QIOChannelBuffer *
29 qio_channel_buffer_new(size_t capacity)
30 {
31 QIOChannelBuffer *ioc;
32
33 ioc = QIO_CHANNEL_BUFFER(object_new(TYPE_QIO_CHANNEL_BUFFER));
34
35 if (capacity) {
36 ioc->data = g_new0(uint8_t, capacity);
37 ioc->capacity = capacity;
38 }
39
40 return ioc;
41 }
42
43
44 static void qio_channel_buffer_finalize(Object *obj)
45 {
46 QIOChannelBuffer *ioc = QIO_CHANNEL_BUFFER(obj);
47 g_free(ioc->data);
48 ioc->capacity = ioc->usage = ioc->offset = 0;
49 }
50
51
52 static ssize_t qio_channel_buffer_readv(QIOChannel *ioc,
53 const struct iovec *iov,
54 size_t niov,
55 int **fds,
56 size_t *nfds,
57 Error **errp)
58 {
59 QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc);
60 ssize_t ret = 0;
61 size_t i;
62
63 for (i = 0; i < niov; i++) {
64 size_t want = iov[i].iov_len;
65 if (bioc->offset >= bioc->usage) {
66 break;
67 }
68 if ((bioc->offset + want) > bioc->usage) {
69 want = bioc->usage - bioc->offset;
70 }
71 memcpy(iov[i].iov_base, bioc->data + bioc->offset, want);
72 ret += want;
73 bioc->offset += want;
74 }
75
76 return ret;
77 }
78
79 static ssize_t qio_channel_buffer_writev(QIOChannel *ioc,
80 const struct iovec *iov,
81 size_t niov,
82 int *fds,
83 size_t nfds,
84 int flags,
85 Error **errp)
86 {
87 QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc);
88 ssize_t ret = 0;
89 size_t i;
90 size_t towrite = 0;
91
92 for (i = 0; i < niov; i++) {
93 towrite += iov[i].iov_len;
94 }
95
96 if ((bioc->offset + towrite) > bioc->capacity) {
97 bioc->capacity = bioc->offset + towrite;
98 bioc->data = g_realloc(bioc->data, bioc->capacity);
99 }
100
101 if (bioc->offset > bioc->usage) {
102 memset(bioc->data, 0, bioc->offset - bioc->usage);
103 bioc->usage = bioc->offset;
104 }
105
106 for (i = 0; i < niov; i++) {
107 memcpy(bioc->data + bioc->usage,
108 iov[i].iov_base,
109 iov[i].iov_len);
110 bioc->usage += iov[i].iov_len;
111 bioc->offset += iov[i].iov_len;
112 ret += iov[i].iov_len;
113 }
114
115 return ret;
116 }
117
118 static int qio_channel_buffer_set_blocking(QIOChannel *ioc G_GNUC_UNUSED,
119 bool enabled G_GNUC_UNUSED,
120 Error **errp G_GNUC_UNUSED)
121 {
122 return 0;
123 }
124
125
126 static off_t qio_channel_buffer_seek(QIOChannel *ioc,
127 off_t offset,
128 int whence,
129 Error **errp)
130 {
131 QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc);
132
133 bioc->offset = offset;
134
135 return offset;
136 }
137
138
139 static int qio_channel_buffer_close(QIOChannel *ioc,
140 Error **errp)
141 {
142 QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc);
143
144 g_free(bioc->data);
145 bioc->data = NULL;
146 bioc->capacity = bioc->usage = bioc->offset = 0;
147
148 return 0;
149 }
150
151
152 typedef struct QIOChannelBufferSource QIOChannelBufferSource;
153 struct QIOChannelBufferSource {
154 GSource parent;
155 QIOChannelBuffer *bioc;
156 GIOCondition condition;
157 };
158
159 static gboolean
160 qio_channel_buffer_source_prepare(GSource *source,
161 gint *timeout)
162 {
163 QIOChannelBufferSource *bsource = (QIOChannelBufferSource *)source;
164
165 *timeout = -1;
166
167 return (G_IO_IN | G_IO_OUT) & bsource->condition;
168 }
169
170 static gboolean
171 qio_channel_buffer_source_check(GSource *source)
172 {
173 QIOChannelBufferSource *bsource = (QIOChannelBufferSource *)source;
174
175 return (G_IO_IN | G_IO_OUT) & bsource->condition;
176 }
177
178 static gboolean
179 qio_channel_buffer_source_dispatch(GSource *source,
180 GSourceFunc callback,
181 gpointer user_data)
182 {
183 QIOChannelFunc func = (QIOChannelFunc)callback;
184 QIOChannelBufferSource *bsource = (QIOChannelBufferSource *)source;
185
186 return (*func)(QIO_CHANNEL(bsource->bioc),
187 ((G_IO_IN | G_IO_OUT) & bsource->condition),
188 user_data);
189 }
190
191 static void
192 qio_channel_buffer_source_finalize(GSource *source)
193 {
194 QIOChannelBufferSource *ssource = (QIOChannelBufferSource *)source;
195
196 object_unref(OBJECT(ssource->bioc));
197 }
198
199 GSourceFuncs qio_channel_buffer_source_funcs = {
200 qio_channel_buffer_source_prepare,
201 qio_channel_buffer_source_check,
202 qio_channel_buffer_source_dispatch,
203 qio_channel_buffer_source_finalize
204 };
205
206 static GSource *qio_channel_buffer_create_watch(QIOChannel *ioc,
207 GIOCondition condition)
208 {
209 QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc);
210 QIOChannelBufferSource *ssource;
211 GSource *source;
212
213 source = g_source_new(&qio_channel_buffer_source_funcs,
214 sizeof(QIOChannelBufferSource));
215 ssource = (QIOChannelBufferSource *)source;
216
217 ssource->bioc = bioc;
218 object_ref(OBJECT(bioc));
219
220 ssource->condition = condition;
221
222 return source;
223 }
224
225
226 static void qio_channel_buffer_class_init(ObjectClass *klass,
227 void *class_data G_GNUC_UNUSED)
228 {
229 QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
230
231 ioc_klass->io_writev = qio_channel_buffer_writev;
232 ioc_klass->io_readv = qio_channel_buffer_readv;
233 ioc_klass->io_set_blocking = qio_channel_buffer_set_blocking;
234 ioc_klass->io_seek = qio_channel_buffer_seek;
235 ioc_klass->io_close = qio_channel_buffer_close;
236 ioc_klass->io_create_watch = qio_channel_buffer_create_watch;
237 }
238
239 static const TypeInfo qio_channel_buffer_info = {
240 .parent = TYPE_QIO_CHANNEL,
241 .name = TYPE_QIO_CHANNEL_BUFFER,
242 .instance_size = sizeof(QIOChannelBuffer),
243 .instance_finalize = qio_channel_buffer_finalize,
244 .class_init = qio_channel_buffer_class_init,
245 };
246
247 static void qio_channel_buffer_register_types(void)
248 {
249 type_register_static(&qio_channel_buffer_info);
250 }
251
252 type_init(qio_channel_buffer_register_types);