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Marc-André Lureau894593a2016-12-12 17:08:59 +03001/*
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 */
Markus Armbruster0b8fa322019-05-23 16:35:07 +020024
Marc-André Lureau894593a2016-12-12 17:08:59 +030025#include "qemu/osdep.h"
Markus Armbruster0b8fa322019-05-23 16:35:07 +020026#include "qemu/module.h"
Marc-André Lureau894593a2016-12-12 17:08:59 +030027#include "qemu/sockets.h"
28#include "qapi/error.h"
Marc-André Lureau8228e352017-01-26 17:19:46 +040029#include "chardev/char.h"
Marc-André Lureaubb2b0582021-08-04 15:08:46 +040030#include "chardev/char-fe.h"
Marc-André Lureau894593a2016-12-12 17:08:59 +030031#include "io/channel-file.h"
32
Marc-André Lureau8228e352017-01-26 17:19:46 +040033#include "chardev/char-fd.h"
34#include "chardev/char-io.h"
Marc-André Lureau894593a2016-12-12 17:08:59 +030035
36/* Called with chr_write_lock held. */
37static int fd_chr_write(Chardev *chr, const uint8_t *buf, int len)
38{
39 FDChardev *s = FD_CHARDEV(chr);
40
Marc-André Lureau46fe3ff2021-07-23 13:54:54 +040041 if (!s->ioc_out) {
42 return -1;
43 }
44
Marc-André Lureau894593a2016-12-12 17:08:59 +030045 return io_channel_send(s->ioc_out, buf, len);
46}
47
48static 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) {
zhanghailiangb19456d2017-04-19 09:15:32 +080067 remove_fd_in_watch(chr);
Marc-André Lureau894593a2016-12-12 17:08:59 +030068 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
78static 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
Marc-André Lureaubb2b0582021-08-04 15:08:46 +040087typedef struct FDSource {
88 GSource parent;
89
90 GIOCondition cond;
91} FDSource;
92
93static gboolean
94fd_source_prepare(GSource *source,
95 gint *timeout_)
96{
97 FDSource *src = (FDSource *)source;
98
99 return src->cond != 0;
100}
101
102static gboolean
103fd_source_check(GSource *source)
104{
105 FDSource *src = (FDSource *)source;
106
107 return src->cond != 0;
108}
109
110static gboolean
111fd_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
126static GSourceFuncs fd_source_funcs = {
127 fd_source_prepare,
128 fd_source_check,
129 fd_source_dispatch,
130 NULL, NULL, NULL
131};
132
133static GSource *fd_source_new(FDChardev *chr)
134{
135 return g_source_new(&fd_source_funcs, sizeof(FDSource));
136}
137
138static 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
Marc-André Lureau894593a2016-12-12 17:08:59 +0300149static GSource *fd_chr_add_watch(Chardev *chr, GIOCondition cond)
150{
151 FDChardev *s = FD_CHARDEV(chr);
Marc-André Lureaubb2b0582021-08-04 15:08:46 +0400152 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);
Marc-André Lureau894593a2016-12-12 17:08:59 +0300166}
167
Peter Xubb86d052017-09-21 14:35:54 +0800168static void fd_chr_update_read_handler(Chardev *chr)
Marc-André Lureau894593a2016-12-12 17:08:59 +0300169{
170 FDChardev *s = FD_CHARDEV(chr);
171
zhanghailiangb19456d2017-04-19 09:15:32 +0800172 remove_fd_in_watch(chr);
Marc-André Lureau894593a2016-12-12 17:08:59 +0300173 if (s->ioc_in) {
zhanghailiangb19456d2017-04-19 09:15:32 +0800174 chr->gsource = io_add_watch_poll(chr, s->ioc_in,
Marc-André Lureau894593a2016-12-12 17:08:59 +0300175 fd_chr_read_poll,
176 fd_chr_read, chr,
Peter Xu6bbb6c02017-09-21 14:35:53 +0800177 chr->gcontext);
Marc-André Lureau894593a2016-12-12 17:08:59 +0300178 }
179}
180
181static void char_fd_finalize(Object *obj)
182{
183 Chardev *chr = CHARDEV(obj);
184 FDChardev *s = FD_CHARDEV(obj);
185
zhanghailiangb19456d2017-04-19 09:15:32 +0800186 remove_fd_in_watch(chr);
Marc-André Lureau894593a2016-12-12 17:08:59 +0300187 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
197int qmp_chardev_open_file_source(char *src, int flags, Error **errp)
198{
199 int fd = -1;
200
Nikita Ivanov8b6aa692022-10-23 12:04:21 +0300201 fd = RETRY_ON_EINTR(qemu_open_old(src, flags, 0666));
Marc-André Lureau894593a2016-12-12 17:08:59 +0300202 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 */
209void qemu_chr_open_fd(Chardev *chr,
210 int fd_in, int fd_out)
211{
212 FDChardev *s = FD_CHARDEV(chr);
Marc-André Lureau733ba022021-07-23 13:59:50 +0400213 g_autofree char *name = NULL;
214
Marc-André Lureaub84bb4d2022-04-25 17:39:06 +0400215 if (fd_out >= 0 && !g_unix_set_fd_nonblocking(fd_out, true, NULL)) {
216 assert(!"Failed to set FD nonblocking");
Marc-André Lureau733ba022021-07-23 13:59:50 +0400217 }
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 }
Marc-André Lureau894593a2016-12-12 17:08:59 +0300226
Marc-André Lureau46fe3ff2021-07-23 13:54:54 +0400227 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);
Marc-André Lureau46fe3ff2021-07-23 13:54:54 +0400231 }
Marc-André Lureau733ba022021-07-23 13:59:50 +0400232
Marc-André Lureau46fe3ff2021-07-23 13:54:54 +0400233 if (fd_out >= 0) {
234 s->ioc_out = QIO_CHANNEL(qio_channel_file_new_fd(fd_out));
Marc-André Lureau733ba022021-07-23 13:59:50 +0400235 g_free(name);
Marc-André Lureau46fe3ff2021-07-23 13:54:54 +0400236 name = g_strdup_printf("chardev-file-out-%s", chr->label);
237 qio_channel_set_name(QIO_CHANNEL(s->ioc_out), name);
Marc-André Lureau46fe3ff2021-07-23 13:54:54 +0400238 }
Marc-André Lureau894593a2016-12-12 17:08:59 +0300239}
240
241static 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
250static 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
259static void register_types(void)
260{
261 type_register_static(&char_fd_type_info);
262}
263
264type_init(register_types);