Merge tag 'pull-riscv-to-apply-20220703-1' of github.com:alistair23/qemu into staging
[qemu.git] / chardev / char-fd.c
1 /*
2 * QEMU System Emulator
3 *
4 * Copyright (c) 2003-2008 Fabrice Bellard
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24
25 #include "qemu/osdep.h"
26 #include "qemu/module.h"
27 #include "qemu/sockets.h"
28 #include "qapi/error.h"
29 #include "chardev/char.h"
30 #include "chardev/char-fe.h"
31 #include "io/channel-file.h"
32
33 #include "chardev/char-fd.h"
34 #include "chardev/char-io.h"
35
36 /* Called with chr_write_lock held. */
37 static int fd_chr_write(Chardev *chr, const uint8_t *buf, int len)
38 {
39 FDChardev *s = FD_CHARDEV(chr);
40
41 if (!s->ioc_out) {
42 return -1;
43 }
44
45 return io_channel_send(s->ioc_out, buf, len);
46 }
47
48 static gboolean fd_chr_read(QIOChannel *chan, GIOCondition cond, void *opaque)
49 {
50 Chardev *chr = CHARDEV(opaque);
51 FDChardev *s = FD_CHARDEV(opaque);
52 int len;
53 uint8_t buf[CHR_READ_BUF_LEN];
54 ssize_t ret;
55
56 len = sizeof(buf);
57 if (len > s->max_size) {
58 len = s->max_size;
59 }
60 if (len == 0) {
61 return TRUE;
62 }
63
64 ret = qio_channel_read(
65 chan, (gchar *)buf, len, NULL);
66 if (ret == 0) {
67 remove_fd_in_watch(chr);
68 qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
69 return FALSE;
70 }
71 if (ret > 0) {
72 qemu_chr_be_write(chr, buf, ret);
73 }
74
75 return TRUE;
76 }
77
78 static int fd_chr_read_poll(void *opaque)
79 {
80 Chardev *chr = CHARDEV(opaque);
81 FDChardev *s = FD_CHARDEV(opaque);
82
83 s->max_size = qemu_chr_be_can_write(chr);
84 return s->max_size;
85 }
86
87 typedef struct FDSource {
88 GSource parent;
89
90 GIOCondition cond;
91 } FDSource;
92
93 static gboolean
94 fd_source_prepare(GSource *source,
95 gint *timeout_)
96 {
97 FDSource *src = (FDSource *)source;
98
99 return src->cond != 0;
100 }
101
102 static gboolean
103 fd_source_check(GSource *source)
104 {
105 FDSource *src = (FDSource *)source;
106
107 return src->cond != 0;
108 }
109
110 static gboolean
111 fd_source_dispatch(GSource *source, GSourceFunc callback,
112 gpointer user_data)
113 {
114 FDSource *src = (FDSource *)source;
115 FEWatchFunc func = (FEWatchFunc)callback;
116 gboolean ret = G_SOURCE_CONTINUE;
117
118 if (src->cond) {
119 ret = func(NULL, src->cond, user_data);
120 src->cond = 0;
121 }
122
123 return ret;
124 }
125
126 static GSourceFuncs fd_source_funcs = {
127 fd_source_prepare,
128 fd_source_check,
129 fd_source_dispatch,
130 NULL, NULL, NULL
131 };
132
133 static GSource *fd_source_new(FDChardev *chr)
134 {
135 return g_source_new(&fd_source_funcs, sizeof(FDSource));
136 }
137
138 static gboolean child_func(GIOChannel *source,
139 GIOCondition condition,
140 gpointer data)
141 {
142 FDSource *parent = data;
143
144 parent->cond |= condition;
145
146 return G_SOURCE_CONTINUE;
147 }
148
149 static GSource *fd_chr_add_watch(Chardev *chr, GIOCondition cond)
150 {
151 FDChardev *s = FD_CHARDEV(chr);
152 g_autoptr(GSource) source = fd_source_new(s);
153
154 if (s->ioc_out) {
155 g_autoptr(GSource) child = qio_channel_create_watch(s->ioc_out, cond & ~G_IO_IN);
156 g_source_set_callback(child, (GSourceFunc)child_func, source, NULL);
157 g_source_add_child_source(source, child);
158 }
159 if (s->ioc_in) {
160 g_autoptr(GSource) child = qio_channel_create_watch(s->ioc_in, cond & ~G_IO_OUT);
161 g_source_set_callback(child, (GSourceFunc)child_func, source, NULL);
162 g_source_add_child_source(source, child);
163 }
164
165 return g_steal_pointer(&source);
166 }
167
168 static void fd_chr_update_read_handler(Chardev *chr)
169 {
170 FDChardev *s = FD_CHARDEV(chr);
171
172 remove_fd_in_watch(chr);
173 if (s->ioc_in) {
174 chr->gsource = io_add_watch_poll(chr, s->ioc_in,
175 fd_chr_read_poll,
176 fd_chr_read, chr,
177 chr->gcontext);
178 }
179 }
180
181 static void char_fd_finalize(Object *obj)
182 {
183 Chardev *chr = CHARDEV(obj);
184 FDChardev *s = FD_CHARDEV(obj);
185
186 remove_fd_in_watch(chr);
187 if (s->ioc_in) {
188 object_unref(OBJECT(s->ioc_in));
189 }
190 if (s->ioc_out) {
191 object_unref(OBJECT(s->ioc_out));
192 }
193
194 qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
195 }
196
197 int qmp_chardev_open_file_source(char *src, int flags, Error **errp)
198 {
199 int fd = -1;
200
201 TFR(fd = qemu_open_old(src, flags, 0666));
202 if (fd == -1) {
203 error_setg_file_open(errp, errno, src);
204 }
205 return fd;
206 }
207
208 /* open a character device to a unix fd */
209 void qemu_chr_open_fd(Chardev *chr,
210 int fd_in, int fd_out)
211 {
212 FDChardev *s = FD_CHARDEV(chr);
213 g_autofree char *name = NULL;
214
215 if (fd_out >= 0 && !g_unix_set_fd_nonblocking(fd_out, true, NULL)) {
216 assert(!"Failed to set FD nonblocking");
217 }
218
219 if (fd_out == fd_in && fd_in >= 0) {
220 s->ioc_in = QIO_CHANNEL(qio_channel_file_new_fd(fd_in));
221 name = g_strdup_printf("chardev-file-%s", chr->label);
222 qio_channel_set_name(QIO_CHANNEL(s->ioc_in), name);
223 s->ioc_out = QIO_CHANNEL(object_ref(s->ioc_in));
224 return;
225 }
226
227 if (fd_in >= 0) {
228 s->ioc_in = QIO_CHANNEL(qio_channel_file_new_fd(fd_in));
229 name = g_strdup_printf("chardev-file-in-%s", chr->label);
230 qio_channel_set_name(QIO_CHANNEL(s->ioc_in), name);
231 }
232
233 if (fd_out >= 0) {
234 s->ioc_out = QIO_CHANNEL(qio_channel_file_new_fd(fd_out));
235 g_free(name);
236 name = g_strdup_printf("chardev-file-out-%s", chr->label);
237 qio_channel_set_name(QIO_CHANNEL(s->ioc_out), name);
238 }
239 }
240
241 static void char_fd_class_init(ObjectClass *oc, void *data)
242 {
243 ChardevClass *cc = CHARDEV_CLASS(oc);
244
245 cc->chr_add_watch = fd_chr_add_watch;
246 cc->chr_write = fd_chr_write;
247 cc->chr_update_read_handler = fd_chr_update_read_handler;
248 }
249
250 static const TypeInfo char_fd_type_info = {
251 .name = TYPE_CHARDEV_FD,
252 .parent = TYPE_CHARDEV,
253 .instance_size = sizeof(FDChardev),
254 .instance_finalize = char_fd_finalize,
255 .class_init = char_fd_class_init,
256 .abstract = true,
257 };
258
259 static void register_types(void)
260 {
261 type_register_static(&char_fd_type_info);
262 }
263
264 type_init(register_types);