xref: /openbmc/qemu/include/chardev/char.h (revision 966f2ec3)
1 #ifndef QEMU_CHAR_H
2 #define QEMU_CHAR_H
3 
4 #include "qapi/qapi-types-char.h"
5 #include "qemu/main-loop.h"
6 #include "qemu/bitmap.h"
7 #include "qom/object.h"
8 
9 #define IAC_EOR 239
10 #define IAC_SE 240
11 #define IAC_NOP 241
12 #define IAC_BREAK 243
13 #define IAC_IP 244
14 #define IAC_SB 250
15 #define IAC 255
16 
17 /* character device */
18 typedef struct CharBackend CharBackend;
19 
20 typedef enum {
21     CHR_EVENT_BREAK, /* serial break char */
22     CHR_EVENT_OPENED, /* new connection established */
23     CHR_EVENT_MUX_IN, /* mux-focus was set to this terminal */
24     CHR_EVENT_MUX_OUT, /* mux-focus will move on */
25     CHR_EVENT_CLOSED /* connection closed.  NOTE: currently this event
26                       * is only bound to the read port of the chardev.
27                       * Normally the read port and write port of a
28                       * chardev should be the same, but it can be
29                       * different, e.g., for fd chardevs, when the two
30                       * fds are different.  So when we received the
31                       * CLOSED event it's still possible that the out
32                       * port is still open.  TODO: we should only send
33                       * the CLOSED event when both ports are closed.
34                       */
35 } QEMUChrEvent;
36 
37 #define CHR_READ_BUF_LEN 4096
38 
39 typedef enum {
40     /* Whether the chardev peer is able to close and
41      * reopen the data channel, thus requiring support
42      * for qemu_chr_wait_connected() to wait for a
43      * valid connection */
44     QEMU_CHAR_FEATURE_RECONNECTABLE,
45     /* Whether it is possible to send/recv file descriptors
46      * over the data channel */
47     QEMU_CHAR_FEATURE_FD_PASS,
48     /* Whether replay or record mode is enabled */
49     QEMU_CHAR_FEATURE_REPLAY,
50 
51     QEMU_CHAR_FEATURE_LAST,
52 } ChardevFeature;
53 
54 #define qemu_chr_replay(chr) qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_REPLAY)
55 
56 struct Chardev {
57     Object parent_obj;
58 
59     QemuMutex chr_write_lock;
60     CharBackend *be;
61     char *label;
62     char *filename;
63     int logfd;
64     int be_open;
65     GSource *gsource;
66     GMainContext *gcontext;
67     DECLARE_BITMAP(features, QEMU_CHAR_FEATURE_LAST);
68 };
69 
70 /**
71  * qemu_chr_new_from_opts:
72  * @opts: see qemu-config.c for a list of valid options
73  *
74  * Create a new character backend from a QemuOpts list.
75  *
76  * Returns: on success: a new character backend
77  *          otherwise:  NULL; @errp specifies the error
78  *                            or left untouched in case of help option
79  */
80 Chardev *qemu_chr_new_from_opts(QemuOpts *opts,
81                                 Error **errp);
82 
83 /**
84  * qemu_chr_parse_common:
85  * @opts: the options that still need parsing
86  * @backend: a new backend
87  *
88  * Parse the common options available to all character backends.
89  */
90 void qemu_chr_parse_common(QemuOpts *opts, ChardevCommon *backend);
91 
92 /**
93  * qemu_chr_parse_opts:
94  *
95  * Parse the options to the ChardevBackend struct.
96  *
97  * Returns: a new backend or NULL on error
98  */
99 ChardevBackend *qemu_chr_parse_opts(QemuOpts *opts,
100                                     Error **errp);
101 
102 /**
103  * qemu_chr_new:
104  * @label: the name of the backend
105  * @filename: the URI
106  *
107  * Create a new character backend from a URI.
108  * Do not implicitly initialize a monitor if the chardev is muxed.
109  *
110  * Returns: a new character backend
111  */
112 Chardev *qemu_chr_new(const char *label, const char *filename);
113 
114 /**
115  * qemu_chr_new_mux_mon:
116  * @label: the name of the backend
117  * @filename: the URI
118  *
119  * Create a new character backend from a URI.
120  * Implicitly initialize a monitor if the chardev is muxed.
121  *
122  * Returns: a new character backend
123  */
124 Chardev *qemu_chr_new_mux_mon(const char *label, const char *filename);
125 
126 /**
127 * qemu_chr_change:
128 * @opts: the new backend options
129  *
130  * Change an existing character backend
131  */
132 void qemu_chr_change(QemuOpts *opts, Error **errp);
133 
134 /**
135  * qemu_chr_cleanup:
136  *
137  * Delete all chardevs (when leaving qemu)
138  */
139 void qemu_chr_cleanup(void);
140 
141 /**
142  * qemu_chr_new_noreplay:
143  * @label: the name of the backend
144  * @filename: the URI
145  * @permit_mux_mon: if chardev is muxed, initialize a monitor
146  *
147  * Create a new character backend from a URI.
148  * Character device communications are not written
149  * into the replay log.
150  *
151  * Returns: a new character backend
152  */
153 Chardev *qemu_chr_new_noreplay(const char *label, const char *filename,
154                                bool permit_mux_mon);
155 
156 /**
157  * qemu_chr_be_can_write:
158  *
159  * Determine how much data the front end can currently accept.  This function
160  * returns the number of bytes the front end can accept.  If it returns 0, the
161  * front end cannot receive data at the moment.  The function must be polled
162  * to determine when data can be received.
163  *
164  * Returns: the number of bytes the front end can receive via @qemu_chr_be_write
165  */
166 int qemu_chr_be_can_write(Chardev *s);
167 
168 /**
169  * qemu_chr_be_write:
170  * @buf: a buffer to receive data from the front end
171  * @len: the number of bytes to receive from the front end
172  *
173  * Write data from the back end to the front end.  Before issuing this call,
174  * the caller should call @qemu_chr_be_can_write to determine how much data
175  * the front end can currently accept.
176  */
177 void qemu_chr_be_write(Chardev *s, uint8_t *buf, int len);
178 
179 /**
180  * qemu_chr_be_write_impl:
181  * @buf: a buffer to receive data from the front end
182  * @len: the number of bytes to receive from the front end
183  *
184  * Implementation of back end writing. Used by replay module.
185  */
186 void qemu_chr_be_write_impl(Chardev *s, uint8_t *buf, int len);
187 
188 /**
189  * qemu_chr_be_update_read_handlers:
190  * @context: the gcontext that will be used to attach the watch sources
191  *
192  * Invoked when frontend read handlers are setup
193  */
194 void qemu_chr_be_update_read_handlers(Chardev *s,
195                                       GMainContext *context);
196 
197 /**
198  * qemu_chr_be_event:
199  * @event: the event to send
200  *
201  * Send an event from the back end to the front end.
202  */
203 void qemu_chr_be_event(Chardev *s, int event);
204 
205 int qemu_chr_add_client(Chardev *s, int fd);
206 Chardev *qemu_chr_find(const char *name);
207 
208 bool qemu_chr_has_feature(Chardev *chr,
209                           ChardevFeature feature);
210 void qemu_chr_set_feature(Chardev *chr,
211                           ChardevFeature feature);
212 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename,
213                                 bool permit_mux_mon);
214 int qemu_chr_write(Chardev *s, const uint8_t *buf, int len, bool write_all);
215 #define qemu_chr_write_all(s, buf, len) qemu_chr_write(s, buf, len, true)
216 int qemu_chr_wait_connected(Chardev *chr, Error **errp);
217 
218 #define TYPE_CHARDEV "chardev"
219 #define CHARDEV(obj) OBJECT_CHECK(Chardev, (obj), TYPE_CHARDEV)
220 #define CHARDEV_CLASS(klass) \
221     OBJECT_CLASS_CHECK(ChardevClass, (klass), TYPE_CHARDEV)
222 #define CHARDEV_GET_CLASS(obj) \
223     OBJECT_GET_CLASS(ChardevClass, (obj), TYPE_CHARDEV)
224 
225 #define TYPE_CHARDEV_NULL "chardev-null"
226 #define TYPE_CHARDEV_MUX "chardev-mux"
227 #define TYPE_CHARDEV_RINGBUF "chardev-ringbuf"
228 #define TYPE_CHARDEV_PTY "chardev-pty"
229 #define TYPE_CHARDEV_CONSOLE "chardev-console"
230 #define TYPE_CHARDEV_STDIO "chardev-stdio"
231 #define TYPE_CHARDEV_PIPE "chardev-pipe"
232 #define TYPE_CHARDEV_MEMORY "chardev-memory"
233 #define TYPE_CHARDEV_PARALLEL "chardev-parallel"
234 #define TYPE_CHARDEV_FILE "chardev-file"
235 #define TYPE_CHARDEV_SERIAL "chardev-serial"
236 #define TYPE_CHARDEV_SOCKET "chardev-socket"
237 #define TYPE_CHARDEV_UDP "chardev-udp"
238 
239 #define CHARDEV_IS_RINGBUF(chr) \
240     object_dynamic_cast(OBJECT(chr), TYPE_CHARDEV_RINGBUF)
241 #define CHARDEV_IS_PTY(chr) \
242     object_dynamic_cast(OBJECT(chr), TYPE_CHARDEV_PTY)
243 
244 typedef struct ChardevClass {
245     ObjectClass parent_class;
246 
247     bool internal; /* TODO: eventually use TYPE_USER_CREATABLE */
248     void (*parse)(QemuOpts *opts, ChardevBackend *backend, Error **errp);
249 
250     void (*open)(Chardev *chr, ChardevBackend *backend,
251                  bool *be_opened, Error **errp);
252 
253     int (*chr_write)(Chardev *s, const uint8_t *buf, int len);
254     int (*chr_sync_read)(Chardev *s, const uint8_t *buf, int len);
255     GSource *(*chr_add_watch)(Chardev *s, GIOCondition cond);
256     void (*chr_update_read_handler)(Chardev *s);
257     int (*chr_ioctl)(Chardev *s, int cmd, void *arg);
258     int (*get_msgfds)(Chardev *s, int* fds, int num);
259     int (*set_msgfds)(Chardev *s, int *fds, int num);
260     int (*chr_add_client)(Chardev *chr, int fd);
261     int (*chr_wait_connected)(Chardev *chr, Error **errp);
262     void (*chr_disconnect)(Chardev *chr);
263     void (*chr_accept_input)(Chardev *chr);
264     void (*chr_set_echo)(Chardev *chr, bool echo);
265     void (*chr_set_fe_open)(Chardev *chr, int fe_open);
266     void (*chr_be_event)(Chardev *s, int event);
267     /* Return 0 if succeeded, 1 if failed */
268     int (*chr_machine_done)(Chardev *chr);
269 } ChardevClass;
270 
271 Chardev *qemu_chardev_new(const char *id, const char *typename,
272                           ChardevBackend *backend, Error **errp);
273 
274 extern int term_escape_char;
275 
276 GSource *qemu_chr_timeout_add_ms(Chardev *chr, guint ms,
277                                  GSourceFunc func, void *private);
278 
279 /* console.c */
280 void qemu_chr_parse_vc(QemuOpts *opts, ChardevBackend *backend, Error **errp);
281 
282 #endif
283