xref: /openbmc/qemu/include/chardev/char.h (revision ac6dd31e)
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     /* 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  *
77  * Create a new character backend from a QemuOpts list.
78  *
79  * Returns: on success: a new character backend
80  *          otherwise:  NULL; @errp specifies the error
81  *                            or left untouched in case of help option
82  */
83 Chardev *qemu_chr_new_from_opts(QemuOpts *opts,
84                                 Error **errp);
85 
86 /**
87  * qemu_chr_parse_common:
88  * @opts: the options that still need parsing
89  * @backend: a new backend
90  *
91  * Parse the common options available to all character backends.
92  */
93 void qemu_chr_parse_common(QemuOpts *opts, ChardevCommon *backend);
94 
95 /**
96  * qemu_chr_parse_opts:
97  *
98  * Parse the options to the ChardevBackend struct.
99  *
100  * Returns: a new backend or NULL on error
101  */
102 ChardevBackend *qemu_chr_parse_opts(QemuOpts *opts,
103                                     Error **errp);
104 
105 /**
106  * qemu_chr_new:
107  * @label: the name of the backend
108  * @filename: the URI
109  *
110  * Create a new character backend from a URI.
111  * Do not implicitly initialize a monitor if the chardev is muxed.
112  *
113  * Returns: a new character backend
114  */
115 Chardev *qemu_chr_new(const char *label, const char *filename);
116 
117 /**
118  * qemu_chr_new_mux_mon:
119  * @label: the name of the backend
120  * @filename: the URI
121  *
122  * Create a new character backend from a URI.
123  * Implicitly initialize a monitor if the chardev is muxed.
124  *
125  * Returns: a new character backend
126  */
127 Chardev *qemu_chr_new_mux_mon(const char *label, const char *filename);
128 
129 /**
130 * qemu_chr_change:
131 * @opts: the new backend options
132  *
133  * Change an existing character backend
134  */
135 void qemu_chr_change(QemuOpts *opts, Error **errp);
136 
137 /**
138  * qemu_chr_cleanup:
139  *
140  * Delete all chardevs (when leaving qemu)
141  */
142 void qemu_chr_cleanup(void);
143 
144 /**
145  * qemu_chr_new_noreplay:
146  * @label: the name of the backend
147  * @filename: the URI
148  * @permit_mux_mon: if chardev is muxed, initialize a monitor
149  *
150  * Create a new character backend from a URI.
151  * Character device communications are not written
152  * into the replay log.
153  *
154  * Returns: a new character backend
155  */
156 Chardev *qemu_chr_new_noreplay(const char *label, const char *filename,
157                                bool permit_mux_mon);
158 
159 /**
160  * qemu_chr_be_can_write:
161  *
162  * Determine how much data the front end can currently accept.  This function
163  * returns the number of bytes the front end can accept.  If it returns 0, the
164  * front end cannot receive data at the moment.  The function must be polled
165  * to determine when data can be received.
166  *
167  * Returns: the number of bytes the front end can receive via @qemu_chr_be_write
168  */
169 int qemu_chr_be_can_write(Chardev *s);
170 
171 /**
172  * qemu_chr_be_write:
173  * @buf: a buffer to receive data from the front end
174  * @len: the number of bytes to receive from the front end
175  *
176  * Write data from the back end to the front end.  Before issuing this call,
177  * the caller should call @qemu_chr_be_can_write to determine how much data
178  * the front end can currently accept.
179  */
180 void qemu_chr_be_write(Chardev *s, uint8_t *buf, int len);
181 
182 /**
183  * qemu_chr_be_write_impl:
184  * @buf: a buffer to receive data from the front end
185  * @len: the number of bytes to receive from the front end
186  *
187  * Implementation of back end writing. Used by replay module.
188  */
189 void qemu_chr_be_write_impl(Chardev *s, uint8_t *buf, int len);
190 
191 /**
192  * qemu_chr_be_update_read_handlers:
193  * @context: the gcontext that will be used to attach the watch sources
194  *
195  * Invoked when frontend read handlers are setup
196  */
197 void qemu_chr_be_update_read_handlers(Chardev *s,
198                                       GMainContext *context);
199 
200 /**
201  * qemu_chr_be_event:
202  * @event: the event to send
203  *
204  * Send an event from the back end to the front end.
205  */
206 void qemu_chr_be_event(Chardev *s, int event);
207 
208 int qemu_chr_add_client(Chardev *s, int fd);
209 Chardev *qemu_chr_find(const char *name);
210 
211 bool qemu_chr_has_feature(Chardev *chr,
212                           ChardevFeature feature);
213 void qemu_chr_set_feature(Chardev *chr,
214                           ChardevFeature feature);
215 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename,
216                                 bool permit_mux_mon);
217 int qemu_chr_write(Chardev *s, const uint8_t *buf, int len, bool write_all);
218 #define qemu_chr_write_all(s, buf, len) qemu_chr_write(s, buf, len, true)
219 int qemu_chr_wait_connected(Chardev *chr, Error **errp);
220 
221 #define TYPE_CHARDEV "chardev"
222 #define CHARDEV(obj) OBJECT_CHECK(Chardev, (obj), TYPE_CHARDEV)
223 #define CHARDEV_CLASS(klass) \
224     OBJECT_CLASS_CHECK(ChardevClass, (klass), TYPE_CHARDEV)
225 #define CHARDEV_GET_CLASS(obj) \
226     OBJECT_GET_CLASS(ChardevClass, (obj), TYPE_CHARDEV)
227 
228 #define TYPE_CHARDEV_NULL "chardev-null"
229 #define TYPE_CHARDEV_MUX "chardev-mux"
230 #define TYPE_CHARDEV_RINGBUF "chardev-ringbuf"
231 #define TYPE_CHARDEV_PTY "chardev-pty"
232 #define TYPE_CHARDEV_CONSOLE "chardev-console"
233 #define TYPE_CHARDEV_STDIO "chardev-stdio"
234 #define TYPE_CHARDEV_PIPE "chardev-pipe"
235 #define TYPE_CHARDEV_MEMORY "chardev-memory"
236 #define TYPE_CHARDEV_PARALLEL "chardev-parallel"
237 #define TYPE_CHARDEV_FILE "chardev-file"
238 #define TYPE_CHARDEV_SERIAL "chardev-serial"
239 #define TYPE_CHARDEV_SOCKET "chardev-socket"
240 #define TYPE_CHARDEV_UDP "chardev-udp"
241 
242 #define CHARDEV_IS_RINGBUF(chr) \
243     object_dynamic_cast(OBJECT(chr), TYPE_CHARDEV_RINGBUF)
244 #define CHARDEV_IS_PTY(chr) \
245     object_dynamic_cast(OBJECT(chr), TYPE_CHARDEV_PTY)
246 
247 typedef struct ChardevClass {
248     ObjectClass parent_class;
249 
250     bool internal; /* TODO: eventually use TYPE_USER_CREATABLE */
251     void (*parse)(QemuOpts *opts, ChardevBackend *backend, Error **errp);
252 
253     void (*open)(Chardev *chr, ChardevBackend *backend,
254                  bool *be_opened, Error **errp);
255 
256     int (*chr_write)(Chardev *s, const uint8_t *buf, int len);
257     int (*chr_sync_read)(Chardev *s, const uint8_t *buf, int len);
258     GSource *(*chr_add_watch)(Chardev *s, GIOCondition cond);
259     void (*chr_update_read_handler)(Chardev *s);
260     int (*chr_ioctl)(Chardev *s, int cmd, void *arg);
261     int (*get_msgfds)(Chardev *s, int* fds, int num);
262     int (*set_msgfds)(Chardev *s, int *fds, int num);
263     int (*chr_add_client)(Chardev *chr, int fd);
264     int (*chr_wait_connected)(Chardev *chr, Error **errp);
265     void (*chr_disconnect)(Chardev *chr);
266     void (*chr_accept_input)(Chardev *chr);
267     void (*chr_set_echo)(Chardev *chr, bool echo);
268     void (*chr_set_fe_open)(Chardev *chr, int fe_open);
269     void (*chr_be_event)(Chardev *s, int event);
270     /* Return 0 if succeeded, 1 if failed */
271     int (*chr_machine_done)(Chardev *chr);
272 } ChardevClass;
273 
274 Chardev *qemu_chardev_new(const char *id, const char *typename,
275                           ChardevBackend *backend, Error **errp);
276 
277 extern int term_escape_char;
278 
279 GSource *qemu_chr_timeout_add_ms(Chardev *chr, guint ms,
280                                  GSourceFunc func, void *private);
281 
282 /* console.c */
283 void qemu_chr_parse_vc(QemuOpts *opts, ChardevBackend *backend, Error **errp);
284 
285 #endif
286