xref: /openbmc/qemu/include/chardev/char.h (revision 2038f8c8)
1 #ifndef QEMU_CHAR_H
2 #define QEMU_CHAR_H
3 
4 #include "qapi/qapi-types-char.h"
5 #include "qemu/bitmap.h"
6 #include "qemu/thread.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     /* Whether the gcontext can be changed after calling
51      * qemu_chr_be_update_read_handlers() */
52     QEMU_CHAR_FEATURE_GCONTEXT,
53 
54     QEMU_CHAR_FEATURE_LAST,
55 } ChardevFeature;
56 
57 #define qemu_chr_replay(chr) qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_REPLAY)
58 
59 struct Chardev {
60     Object parent_obj;
61 
62     QemuMutex chr_write_lock;
63     CharBackend *be;
64     char *label;
65     char *filename;
66     int logfd;
67     int be_open;
68     GSource *gsource;
69     GMainContext *gcontext;
70     DECLARE_BITMAP(features, QEMU_CHAR_FEATURE_LAST);
71 };
72 
73 /**
74  * qemu_chr_new_from_opts:
75  * @opts: see qemu-config.c for a list of valid options
76  * @context: the #GMainContext to be used at initialization time
77  *
78  * Create a new character backend from a QemuOpts list.
79  *
80  * Returns: on success: a new character backend
81  *          otherwise:  NULL; @errp specifies the error
82  *                            or left untouched in case of help option
83  */
84 Chardev *qemu_chr_new_from_opts(QemuOpts *opts,
85                                 GMainContext *context,
86                                 Error **errp);
87 
88 /**
89  * qemu_chr_parse_common:
90  * @opts: the options that still need parsing
91  * @backend: a new backend
92  *
93  * Parse the common options available to all character backends.
94  */
95 void qemu_chr_parse_common(QemuOpts *opts, ChardevCommon *backend);
96 
97 /**
98  * qemu_chr_parse_opts:
99  *
100  * Parse the options to the ChardevBackend struct.
101  *
102  * Returns: a new backend or NULL on error
103  */
104 ChardevBackend *qemu_chr_parse_opts(QemuOpts *opts,
105                                     Error **errp);
106 
107 /**
108  * qemu_chr_new:
109  * @label: the name of the backend
110  * @filename: the URI
111  * @context: the #GMainContext to be used at initialization time
112  *
113  * Create a new character backend from a URI.
114  * Do not implicitly initialize a monitor if the chardev is muxed.
115  *
116  * Returns: a new character backend
117  */
118 Chardev *qemu_chr_new(const char *label, const char *filename,
119                       GMainContext *context);
120 
121 /**
122  * qemu_chr_new_mux_mon:
123  * @label: the name of the backend
124  * @filename: the URI
125  * @context: the #GMainContext to be used at initialization time
126  *
127  * Create a new character backend from a URI.
128  * Implicitly initialize a monitor if the chardev is muxed.
129  *
130  * Returns: a new character backend
131  */
132 Chardev *qemu_chr_new_mux_mon(const char *label, const char *filename,
133                               GMainContext *context);
134 
135 /**
136 * qemu_chr_change:
137 * @opts: the new backend options
138  *
139  * Change an existing character backend
140  */
141 void qemu_chr_change(QemuOpts *opts, Error **errp);
142 
143 /**
144  * qemu_chr_cleanup:
145  *
146  * Delete all chardevs (when leaving qemu)
147  */
148 void qemu_chr_cleanup(void);
149 
150 /**
151  * qemu_chr_new_noreplay:
152  * @label: the name of the backend
153  * @filename: the URI
154  * @permit_mux_mon: if chardev is muxed, initialize a monitor
155  * @context: the #GMainContext to be used at initialization time
156  *
157  * Create a new character backend from a URI.
158  * Character device communications are not written
159  * into the replay log.
160  *
161  * Returns: a new character backend
162  */
163 Chardev *qemu_chr_new_noreplay(const char *label, const char *filename,
164                                bool permit_mux_mon, GMainContext *context);
165 
166 /**
167  * qemu_chr_be_can_write:
168  *
169  * Determine how much data the front end can currently accept.  This function
170  * returns the number of bytes the front end can accept.  If it returns 0, the
171  * front end cannot receive data at the moment.  The function must be polled
172  * to determine when data can be received.
173  *
174  * Returns: the number of bytes the front end can receive via @qemu_chr_be_write
175  */
176 int qemu_chr_be_can_write(Chardev *s);
177 
178 /**
179  * qemu_chr_be_write:
180  * @buf: a buffer to receive data from the front end
181  * @len: the number of bytes to receive from the front end
182  *
183  * Write data from the back end to the front end.  Before issuing this call,
184  * the caller should call @qemu_chr_be_can_write to determine how much data
185  * the front end can currently accept.
186  */
187 void qemu_chr_be_write(Chardev *s, uint8_t *buf, int len);
188 
189 /**
190  * qemu_chr_be_write_impl:
191  * @buf: a buffer to receive data from the front end
192  * @len: the number of bytes to receive from the front end
193  *
194  * Implementation of back end writing. Used by replay module.
195  */
196 void qemu_chr_be_write_impl(Chardev *s, uint8_t *buf, int len);
197 
198 /**
199  * qemu_chr_be_update_read_handlers:
200  * @context: the gcontext that will be used to attach the watch sources
201  *
202  * Invoked when frontend read handlers are setup
203  */
204 void qemu_chr_be_update_read_handlers(Chardev *s,
205                                       GMainContext *context);
206 
207 /**
208  * qemu_chr_be_event:
209  * @event: the event to send
210  *
211  * Send an event from the back end to the front end.
212  */
213 void qemu_chr_be_event(Chardev *s, int event);
214 
215 int qemu_chr_add_client(Chardev *s, int fd);
216 Chardev *qemu_chr_find(const char *name);
217 
218 bool qemu_chr_has_feature(Chardev *chr,
219                           ChardevFeature feature);
220 void qemu_chr_set_feature(Chardev *chr,
221                           ChardevFeature feature);
222 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename,
223                                 bool permit_mux_mon);
224 int qemu_chr_write(Chardev *s, const uint8_t *buf, int len, bool write_all);
225 #define qemu_chr_write_all(s, buf, len) qemu_chr_write(s, buf, len, true)
226 int qemu_chr_wait_connected(Chardev *chr, Error **errp);
227 
228 #define TYPE_CHARDEV "chardev"
229 #define CHARDEV(obj) OBJECT_CHECK(Chardev, (obj), TYPE_CHARDEV)
230 #define CHARDEV_CLASS(klass) \
231     OBJECT_CLASS_CHECK(ChardevClass, (klass), TYPE_CHARDEV)
232 #define CHARDEV_GET_CLASS(obj) \
233     OBJECT_GET_CLASS(ChardevClass, (obj), TYPE_CHARDEV)
234 
235 #define TYPE_CHARDEV_NULL "chardev-null"
236 #define TYPE_CHARDEV_MUX "chardev-mux"
237 #define TYPE_CHARDEV_RINGBUF "chardev-ringbuf"
238 #define TYPE_CHARDEV_PTY "chardev-pty"
239 #define TYPE_CHARDEV_CONSOLE "chardev-console"
240 #define TYPE_CHARDEV_STDIO "chardev-stdio"
241 #define TYPE_CHARDEV_PIPE "chardev-pipe"
242 #define TYPE_CHARDEV_MEMORY "chardev-memory"
243 #define TYPE_CHARDEV_PARALLEL "chardev-parallel"
244 #define TYPE_CHARDEV_FILE "chardev-file"
245 #define TYPE_CHARDEV_SERIAL "chardev-serial"
246 #define TYPE_CHARDEV_SOCKET "chardev-socket"
247 #define TYPE_CHARDEV_UDP "chardev-udp"
248 
249 #define CHARDEV_IS_RINGBUF(chr) \
250     object_dynamic_cast(OBJECT(chr), TYPE_CHARDEV_RINGBUF)
251 #define CHARDEV_IS_PTY(chr) \
252     object_dynamic_cast(OBJECT(chr), TYPE_CHARDEV_PTY)
253 
254 typedef struct ChardevClass {
255     ObjectClass parent_class;
256 
257     bool internal; /* TODO: eventually use TYPE_USER_CREATABLE */
258     void (*parse)(QemuOpts *opts, ChardevBackend *backend, Error **errp);
259 
260     void (*open)(Chardev *chr, ChardevBackend *backend,
261                  bool *be_opened, Error **errp);
262 
263     int (*chr_write)(Chardev *s, const uint8_t *buf, int len);
264     int (*chr_sync_read)(Chardev *s, const uint8_t *buf, int len);
265     GSource *(*chr_add_watch)(Chardev *s, GIOCondition cond);
266     void (*chr_update_read_handler)(Chardev *s);
267     int (*chr_ioctl)(Chardev *s, int cmd, void *arg);
268     int (*get_msgfds)(Chardev *s, int* fds, int num);
269     int (*set_msgfds)(Chardev *s, int *fds, int num);
270     int (*chr_add_client)(Chardev *chr, int fd);
271     int (*chr_wait_connected)(Chardev *chr, Error **errp);
272     void (*chr_disconnect)(Chardev *chr);
273     void (*chr_accept_input)(Chardev *chr);
274     void (*chr_set_echo)(Chardev *chr, bool echo);
275     void (*chr_set_fe_open)(Chardev *chr, int fe_open);
276     void (*chr_be_event)(Chardev *s, int event);
277     /* Return 0 if succeeded, 1 if failed */
278     int (*chr_machine_done)(Chardev *chr);
279 } ChardevClass;
280 
281 Chardev *qemu_chardev_new(const char *id, const char *typename,
282                           ChardevBackend *backend, GMainContext *context,
283                           Error **errp);
284 
285 extern int term_escape_char;
286 
287 GSource *qemu_chr_timeout_add_ms(Chardev *chr, guint ms,
288                                  GSourceFunc func, void *private);
289 
290 /* console.c */
291 void qemu_chr_parse_vc(QemuOpts *opts, ChardevBackend *backend, Error **errp);
292 
293 #endif
294