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 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 | Error **errp) |
85 | { |
86 | QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc); |
87 | ssize_t ret = 0; |
88 | size_t i; |
89 | size_t towrite = 0; |
90 | |
91 | for (i = 0; i < niov; i++) { |
92 | towrite += iov[i].iov_len; |
93 | } |
94 | |
95 | if ((bioc->offset + towrite) > bioc->capacity) { |
96 | bioc->capacity = bioc->offset + towrite; |
97 | bioc->data = g_realloc(bioc->data, bioc->capacity); |
98 | } |
99 | |
100 | if (bioc->offset > bioc->usage) { |
101 | memset(bioc->data, 0, bioc->offset - bioc->usage); |
102 | bioc->usage = bioc->offset; |
103 | } |
104 | |
105 | for (i = 0; i < niov; i++) { |
106 | memcpy(bioc->data + bioc->usage, |
107 | iov[i].iov_base, |
108 | iov[i].iov_len); |
109 | bioc->usage += iov[i].iov_len; |
110 | bioc->offset += iov[i].iov_len; |
111 | ret += iov[i].iov_len; |
112 | } |
113 | |
114 | return ret; |
115 | } |
116 | |
117 | static int qio_channel_buffer_set_blocking(QIOChannel *ioc G_GNUC_UNUSED, |
118 | bool enabled G_GNUC_UNUSED, |
119 | Error **errp G_GNUC_UNUSED) |
120 | { |
121 | return 0; |
122 | } |
123 | |
124 | |
125 | static off_t qio_channel_buffer_seek(QIOChannel *ioc, |
126 | off_t offset, |
127 | int whence, |
128 | Error **errp) |
129 | { |
130 | QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc); |
131 | |
132 | bioc->offset = offset; |
133 | |
134 | return offset; |
135 | } |
136 | |
137 | |
138 | static int qio_channel_buffer_close(QIOChannel *ioc, |
139 | Error **errp) |
140 | { |
141 | QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc); |
142 | |
143 | g_free(bioc->data); |
144 | bioc->data = NULL; |
145 | bioc->capacity = bioc->usage = bioc->offset = 0; |
146 | |
147 | return 0; |
148 | } |
149 | |
150 | |
151 | typedef struct QIOChannelBufferSource QIOChannelBufferSource; |
152 | struct QIOChannelBufferSource { |
153 | GSource parent; |
154 | QIOChannelBuffer *bioc; |
155 | GIOCondition condition; |
156 | }; |
157 | |
158 | static gboolean |
159 | qio_channel_buffer_source_prepare(GSource *source, |
160 | gint *timeout) |
161 | { |
162 | QIOChannelBufferSource *bsource = (QIOChannelBufferSource *)source; |
163 | |
164 | *timeout = -1; |
165 | |
166 | return (G_IO_IN | G_IO_OUT) & bsource->condition; |
167 | } |
168 | |
169 | static gboolean |
170 | qio_channel_buffer_source_check(GSource *source) |
171 | { |
172 | QIOChannelBufferSource *bsource = (QIOChannelBufferSource *)source; |
173 | |
174 | return (G_IO_IN | G_IO_OUT) & bsource->condition; |
175 | } |
176 | |
177 | static gboolean |
178 | qio_channel_buffer_source_dispatch(GSource *source, |
179 | GSourceFunc callback, |
180 | gpointer user_data) |
181 | { |
182 | QIOChannelFunc func = (QIOChannelFunc)callback; |
183 | QIOChannelBufferSource *bsource = (QIOChannelBufferSource *)source; |
184 | |
185 | return (*func)(QIO_CHANNEL(bsource->bioc), |
186 | ((G_IO_IN | G_IO_OUT) & bsource->condition), |
187 | user_data); |
188 | } |
189 | |
190 | static void |
191 | qio_channel_buffer_source_finalize(GSource *source) |
192 | { |
193 | QIOChannelBufferSource *ssource = (QIOChannelBufferSource *)source; |
194 | |
195 | object_unref(OBJECT(ssource->bioc)); |
196 | } |
197 | |
198 | GSourceFuncs qio_channel_buffer_source_funcs = { |
199 | qio_channel_buffer_source_prepare, |
200 | qio_channel_buffer_source_check, |
201 | qio_channel_buffer_source_dispatch, |
202 | qio_channel_buffer_source_finalize |
203 | }; |
204 | |
205 | static GSource *qio_channel_buffer_create_watch(QIOChannel *ioc, |
206 | GIOCondition condition) |
207 | { |
208 | QIOChannelBuffer *bioc = QIO_CHANNEL_BUFFER(ioc); |
209 | QIOChannelBufferSource *ssource; |
210 | GSource *source; |
211 | |
212 | source = g_source_new(&qio_channel_buffer_source_funcs, |
213 | sizeof(QIOChannelBufferSource)); |
214 | ssource = (QIOChannelBufferSource *)source; |
215 | |
216 | ssource->bioc = bioc; |
217 | object_ref(OBJECT(bioc)); |
218 | |
219 | ssource->condition = condition; |
220 | |
221 | return source; |
222 | } |
223 | |
224 | |
225 | static void qio_channel_buffer_class_init(ObjectClass *klass, |
226 | void *class_data G_GNUC_UNUSED) |
227 | { |
228 | QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass); |
229 | |
230 | ioc_klass->io_writev = qio_channel_buffer_writev; |
231 | ioc_klass->io_readv = qio_channel_buffer_readv; |
232 | ioc_klass->io_set_blocking = qio_channel_buffer_set_blocking; |
233 | ioc_klass->io_seek = qio_channel_buffer_seek; |
234 | ioc_klass->io_close = qio_channel_buffer_close; |
235 | ioc_klass->io_create_watch = qio_channel_buffer_create_watch; |
236 | } |
237 | |
238 | static const TypeInfo qio_channel_buffer_info = { |
239 | .parent = TYPE_QIO_CHANNEL, |
240 | .name = TYPE_QIO_CHANNEL_BUFFER, |
241 | .instance_size = sizeof(QIOChannelBuffer), |
242 | .instance_finalize = qio_channel_buffer_finalize, |
243 | .class_init = qio_channel_buffer_class_init, |
244 | }; |
245 | |
246 | static void qio_channel_buffer_register_types(void) |
247 | { |
248 | type_register_static(&qio_channel_buffer_info); |
249 | } |
250 | |
251 | type_init(qio_channel_buffer_register_types); |
252 | |