xref: /openbmc/qemu/include/chardev/char.h (revision 922a01a013d2270682a188258cbccacfecf8129c)
1 #ifndef QEMU_CHAR_H
2 #define QEMU_CHAR_H
3 
4 #include "qemu/main-loop.h"
5 #include "qemu/bitmap.h"
6 #include "qom/object.h"
7 
8 #define IAC_EOR 239
9 #define IAC_SE 240
10 #define IAC_NOP 241
11 #define IAC_BREAK 243
12 #define IAC_IP 244
13 #define IAC_SB 250
14 #define IAC 255
15 
16 /* character device */
17 typedef struct CharBackend CharBackend;
18 
19 typedef enum {
20     CHR_EVENT_BREAK, /* serial break char */
21     CHR_EVENT_OPENED, /* new connection established */
22     CHR_EVENT_MUX_IN, /* mux-focus was set to this terminal */
23     CHR_EVENT_MUX_OUT, /* mux-focus will move on */
24     CHR_EVENT_CLOSED /* connection closed */
25 } QEMUChrEvent;
26 
27 #define CHR_READ_BUF_LEN 4096
28 
29 typedef enum {
30     /* Whether the chardev peer is able to close and
31      * reopen the data channel, thus requiring support
32      * for qemu_chr_wait_connected() to wait for a
33      * valid connection */
34     QEMU_CHAR_FEATURE_RECONNECTABLE,
35     /* Whether it is possible to send/recv file descriptors
36      * over the data channel */
37     QEMU_CHAR_FEATURE_FD_PASS,
38     /* Whether replay or record mode is enabled */
39     QEMU_CHAR_FEATURE_REPLAY,
40 
41     QEMU_CHAR_FEATURE_LAST,
42 } ChardevFeature;
43 
44 #define qemu_chr_replay(chr) qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_REPLAY)
45 
46 struct Chardev {
47     Object parent_obj;
48 
49     QemuMutex chr_write_lock;
50     CharBackend *be;
51     char *label;
52     char *filename;
53     int logfd;
54     int be_open;
55     GSource *gsource;
56     GMainContext *gcontext;
57     DECLARE_BITMAP(features, QEMU_CHAR_FEATURE_LAST);
58 };
59 
60 /**
61  * @qemu_chr_new_from_opts:
62  *
63  * Create a new character backend from a QemuOpts list.
64  *
65  * @opts see qemu-config.c for a list of valid options
66  *
67  * Returns: on success: a new character backend
68  *          otherwise:  NULL; @errp specifies the error
69  *                            or left untouched in case of help option
70  */
71 Chardev *qemu_chr_new_from_opts(QemuOpts *opts,
72                                 Error **errp);
73 
74 /**
75  * @qemu_chr_parse_common:
76  *
77  * Parse the common options available to all character backends.
78  *
79  * @opts the options that still need parsing
80  * @backend a new backend
81  */
82 void qemu_chr_parse_common(QemuOpts *opts, ChardevCommon *backend);
83 
84 /**
85  * @qemu_chr_parse_opts:
86  *
87  * Parse the options to the ChardevBackend struct.
88  *
89  * Returns: a new backend or NULL on error
90  */
91 ChardevBackend *qemu_chr_parse_opts(QemuOpts *opts,
92                                     Error **errp);
93 
94 /**
95  * @qemu_chr_new:
96  *
97  * Create a new character backend from a URI.
98  *
99  * @label the name of the backend
100  * @filename the URI
101  *
102  * Returns: a new character backend
103  */
104 Chardev *qemu_chr_new(const char *label, const char *filename);
105 
106 /**
107  * @qemu_chr_change:
108  *
109  * Change an existing character backend
110  *
111  * @opts the new backend options
112  */
113 void qemu_chr_change(QemuOpts *opts, Error **errp);
114 
115 /**
116  * @qemu_chr_cleanup:
117  *
118  * Delete all chardevs (when leaving qemu)
119  */
120 void qemu_chr_cleanup(void);
121 
122 /**
123  * @qemu_chr_new_noreplay:
124  *
125  * Create a new character backend from a URI.
126  * Character device communications are not written
127  * into the replay log.
128  *
129  * @label the name of the backend
130  * @filename the URI
131  *
132  * Returns: a new character backend
133  */
134 Chardev *qemu_chr_new_noreplay(const char *label, const char *filename);
135 
136 /**
137  * @qemu_chr_be_can_write:
138  *
139  * Determine how much data the front end can currently accept.  This function
140  * returns the number of bytes the front end can accept.  If it returns 0, the
141  * front end cannot receive data at the moment.  The function must be polled
142  * to determine when data can be received.
143  *
144  * Returns: the number of bytes the front end can receive via @qemu_chr_be_write
145  */
146 int qemu_chr_be_can_write(Chardev *s);
147 
148 /**
149  * @qemu_chr_be_write:
150  *
151  * Write data from the back end to the front end.  Before issuing this call,
152  * the caller should call @qemu_chr_be_can_write to determine how much data
153  * the front end can currently accept.
154  *
155  * @buf a buffer to receive data from the front end
156  * @len the number of bytes to receive from the front end
157  */
158 void qemu_chr_be_write(Chardev *s, uint8_t *buf, int len);
159 
160 /**
161  * @qemu_chr_be_write_impl:
162  *
163  * Implementation of back end writing. Used by replay module.
164  *
165  * @buf a buffer to receive data from the front end
166  * @len the number of bytes to receive from the front end
167  */
168 void qemu_chr_be_write_impl(Chardev *s, uint8_t *buf, int len);
169 
170 /**
171  * @qemu_chr_be_update_read_handlers:
172  *
173  * Invoked when frontend read handlers are setup
174  *
175  * @context the gcontext that will be used to attach the watch sources
176  */
177 void qemu_chr_be_update_read_handlers(Chardev *s,
178                                       GMainContext *context);
179 
180 /**
181  * @qemu_chr_be_event:
182  *
183  * Send an event from the back end to the front end.
184  *
185  * @event the event to send
186  */
187 void qemu_chr_be_event(Chardev *s, int event);
188 
189 int qemu_chr_add_client(Chardev *s, int fd);
190 Chardev *qemu_chr_find(const char *name);
191 
192 bool qemu_chr_has_feature(Chardev *chr,
193                           ChardevFeature feature);
194 void qemu_chr_set_feature(Chardev *chr,
195                           ChardevFeature feature);
196 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename);
197 int qemu_chr_write(Chardev *s, const uint8_t *buf, int len, bool write_all);
198 #define qemu_chr_write_all(s, buf, len) qemu_chr_write(s, buf, len, true)
199 int qemu_chr_wait_connected(Chardev *chr, Error **errp);
200 
201 #define TYPE_CHARDEV "chardev"
202 #define CHARDEV(obj) OBJECT_CHECK(Chardev, (obj), TYPE_CHARDEV)
203 #define CHARDEV_CLASS(klass) \
204     OBJECT_CLASS_CHECK(ChardevClass, (klass), TYPE_CHARDEV)
205 #define CHARDEV_GET_CLASS(obj) \
206     OBJECT_GET_CLASS(ChardevClass, (obj), TYPE_CHARDEV)
207 
208 #define TYPE_CHARDEV_NULL "chardev-null"
209 #define TYPE_CHARDEV_MUX "chardev-mux"
210 #define TYPE_CHARDEV_RINGBUF "chardev-ringbuf"
211 #define TYPE_CHARDEV_PTY "chardev-pty"
212 #define TYPE_CHARDEV_CONSOLE "chardev-console"
213 #define TYPE_CHARDEV_STDIO "chardev-stdio"
214 #define TYPE_CHARDEV_PIPE "chardev-pipe"
215 #define TYPE_CHARDEV_MEMORY "chardev-memory"
216 #define TYPE_CHARDEV_PARALLEL "chardev-parallel"
217 #define TYPE_CHARDEV_FILE "chardev-file"
218 #define TYPE_CHARDEV_SERIAL "chardev-serial"
219 #define TYPE_CHARDEV_SOCKET "chardev-socket"
220 #define TYPE_CHARDEV_UDP "chardev-udp"
221 
222 #define CHARDEV_IS_RINGBUF(chr) \
223     object_dynamic_cast(OBJECT(chr), TYPE_CHARDEV_RINGBUF)
224 #define CHARDEV_IS_PTY(chr) \
225     object_dynamic_cast(OBJECT(chr), TYPE_CHARDEV_PTY)
226 
227 typedef struct ChardevClass {
228     ObjectClass parent_class;
229 
230     bool internal; /* TODO: eventually use TYPE_USER_CREATABLE */
231     void (*parse)(QemuOpts *opts, ChardevBackend *backend, Error **errp);
232 
233     void (*open)(Chardev *chr, ChardevBackend *backend,
234                  bool *be_opened, Error **errp);
235 
236     int (*chr_write)(Chardev *s, const uint8_t *buf, int len);
237     int (*chr_sync_read)(Chardev *s, const uint8_t *buf, int len);
238     GSource *(*chr_add_watch)(Chardev *s, GIOCondition cond);
239     void (*chr_update_read_handler)(Chardev *s);
240     int (*chr_ioctl)(Chardev *s, int cmd, void *arg);
241     int (*get_msgfds)(Chardev *s, int* fds, int num);
242     int (*set_msgfds)(Chardev *s, int *fds, int num);
243     int (*chr_add_client)(Chardev *chr, int fd);
244     int (*chr_wait_connected)(Chardev *chr, Error **errp);
245     void (*chr_disconnect)(Chardev *chr);
246     void (*chr_accept_input)(Chardev *chr);
247     void (*chr_set_echo)(Chardev *chr, bool echo);
248     void (*chr_set_fe_open)(Chardev *chr, int fe_open);
249     void (*chr_be_event)(Chardev *s, int event);
250 } ChardevClass;
251 
252 Chardev *qemu_chardev_new(const char *id, const char *typename,
253                           ChardevBackend *backend, Error **errp);
254 
255 extern int term_escape_char;
256 
257 GSource *qemu_chr_timeout_add_ms(Chardev *chr, guint ms,
258                                  GSourceFunc func, void *private);
259 
260 /* console.c */
261 void qemu_chr_parse_vc(QemuOpts *opts, ChardevBackend *backend, Error **errp);
262 
263 #endif
264