xref: /openbmc/qemu/include/chardev/char.h (revision 646f34fa)
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  *
73  * Create a new character backend from a QemuOpts list.
74  *
75  * @opts see qemu-config.c for a list of valid options
76  *
77  * Returns: on success: a new character backend
78  *          otherwise:  NULL; @errp specifies the error
79  *                            or left untouched in case of help option
80  */
81 Chardev *qemu_chr_new_from_opts(QemuOpts *opts,
82                                 Error **errp);
83 
84 /**
85  * @qemu_chr_parse_common:
86  *
87  * Parse the common options available to all character backends.
88  *
89  * @opts the options that still need parsing
90  * @backend a new backend
91  */
92 void qemu_chr_parse_common(QemuOpts *opts, ChardevCommon *backend);
93 
94 /**
95  * @qemu_chr_parse_opts:
96  *
97  * Parse the options to the ChardevBackend struct.
98  *
99  * Returns: a new backend or NULL on error
100  */
101 ChardevBackend *qemu_chr_parse_opts(QemuOpts *opts,
102                                     Error **errp);
103 
104 /**
105  * @qemu_chr_new:
106  *
107  * Create a new character backend from a URI.
108  *
109  * @label the name of the backend
110  * @filename the URI
111  *
112  * Returns: a new character backend
113  */
114 Chardev *qemu_chr_new(const char *label, const char *filename);
115 
116 /**
117  * @qemu_chr_change:
118  *
119  * Change an existing character backend
120  *
121  * @opts the new backend options
122  */
123 void qemu_chr_change(QemuOpts *opts, Error **errp);
124 
125 /**
126  * @qemu_chr_cleanup:
127  *
128  * Delete all chardevs (when leaving qemu)
129  */
130 void qemu_chr_cleanup(void);
131 
132 /**
133  * @qemu_chr_new_noreplay:
134  *
135  * Create a new character backend from a URI.
136  * Character device communications are not written
137  * into the replay log.
138  *
139  * @label the name of the backend
140  * @filename the URI
141  *
142  * Returns: a new character backend
143  */
144 Chardev *qemu_chr_new_noreplay(const char *label, const char *filename);
145 
146 /**
147  * @qemu_chr_be_can_write:
148  *
149  * Determine how much data the front end can currently accept.  This function
150  * returns the number of bytes the front end can accept.  If it returns 0, the
151  * front end cannot receive data at the moment.  The function must be polled
152  * to determine when data can be received.
153  *
154  * Returns: the number of bytes the front end can receive via @qemu_chr_be_write
155  */
156 int qemu_chr_be_can_write(Chardev *s);
157 
158 /**
159  * @qemu_chr_be_write:
160  *
161  * Write data from the back end to the front end.  Before issuing this call,
162  * the caller should call @qemu_chr_be_can_write to determine how much data
163  * the front end can currently accept.
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(Chardev *s, uint8_t *buf, int len);
169 
170 /**
171  * @qemu_chr_be_write_impl:
172  *
173  * Implementation of back end writing. Used by replay module.
174  *
175  * @buf a buffer to receive data from the front end
176  * @len the number of bytes to receive from the front end
177  */
178 void qemu_chr_be_write_impl(Chardev *s, uint8_t *buf, int len);
179 
180 /**
181  * @qemu_chr_be_update_read_handlers:
182  *
183  * Invoked when frontend read handlers are setup
184  *
185  * @context the gcontext that will be used to attach the watch sources
186  */
187 void qemu_chr_be_update_read_handlers(Chardev *s,
188                                       GMainContext *context);
189 
190 /**
191  * @qemu_chr_be_event:
192  *
193  * Send an event from the back end to the front end.
194  *
195  * @event the event to send
196  */
197 void qemu_chr_be_event(Chardev *s, int event);
198 
199 int qemu_chr_add_client(Chardev *s, int fd);
200 Chardev *qemu_chr_find(const char *name);
201 
202 bool qemu_chr_has_feature(Chardev *chr,
203                           ChardevFeature feature);
204 void qemu_chr_set_feature(Chardev *chr,
205                           ChardevFeature feature);
206 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename);
207 int qemu_chr_write(Chardev *s, const uint8_t *buf, int len, bool write_all);
208 #define qemu_chr_write_all(s, buf, len) qemu_chr_write(s, buf, len, true)
209 int qemu_chr_wait_connected(Chardev *chr, Error **errp);
210 
211 #define TYPE_CHARDEV "chardev"
212 #define CHARDEV(obj) OBJECT_CHECK(Chardev, (obj), TYPE_CHARDEV)
213 #define CHARDEV_CLASS(klass) \
214     OBJECT_CLASS_CHECK(ChardevClass, (klass), TYPE_CHARDEV)
215 #define CHARDEV_GET_CLASS(obj) \
216     OBJECT_GET_CLASS(ChardevClass, (obj), TYPE_CHARDEV)
217 
218 #define TYPE_CHARDEV_NULL "chardev-null"
219 #define TYPE_CHARDEV_MUX "chardev-mux"
220 #define TYPE_CHARDEV_RINGBUF "chardev-ringbuf"
221 #define TYPE_CHARDEV_PTY "chardev-pty"
222 #define TYPE_CHARDEV_CONSOLE "chardev-console"
223 #define TYPE_CHARDEV_STDIO "chardev-stdio"
224 #define TYPE_CHARDEV_PIPE "chardev-pipe"
225 #define TYPE_CHARDEV_MEMORY "chardev-memory"
226 #define TYPE_CHARDEV_PARALLEL "chardev-parallel"
227 #define TYPE_CHARDEV_FILE "chardev-file"
228 #define TYPE_CHARDEV_SERIAL "chardev-serial"
229 #define TYPE_CHARDEV_SOCKET "chardev-socket"
230 #define TYPE_CHARDEV_UDP "chardev-udp"
231 
232 #define CHARDEV_IS_RINGBUF(chr) \
233     object_dynamic_cast(OBJECT(chr), TYPE_CHARDEV_RINGBUF)
234 #define CHARDEV_IS_PTY(chr) \
235     object_dynamic_cast(OBJECT(chr), TYPE_CHARDEV_PTY)
236 
237 typedef struct ChardevClass {
238     ObjectClass parent_class;
239 
240     bool internal; /* TODO: eventually use TYPE_USER_CREATABLE */
241     void (*parse)(QemuOpts *opts, ChardevBackend *backend, Error **errp);
242 
243     void (*open)(Chardev *chr, ChardevBackend *backend,
244                  bool *be_opened, Error **errp);
245 
246     int (*chr_write)(Chardev *s, const uint8_t *buf, int len);
247     int (*chr_sync_read)(Chardev *s, const uint8_t *buf, int len);
248     GSource *(*chr_add_watch)(Chardev *s, GIOCondition cond);
249     void (*chr_update_read_handler)(Chardev *s);
250     int (*chr_ioctl)(Chardev *s, int cmd, void *arg);
251     int (*get_msgfds)(Chardev *s, int* fds, int num);
252     int (*set_msgfds)(Chardev *s, int *fds, int num);
253     int (*chr_add_client)(Chardev *chr, int fd);
254     int (*chr_wait_connected)(Chardev *chr, Error **errp);
255     void (*chr_disconnect)(Chardev *chr);
256     void (*chr_accept_input)(Chardev *chr);
257     void (*chr_set_echo)(Chardev *chr, bool echo);
258     void (*chr_set_fe_open)(Chardev *chr, int fe_open);
259     void (*chr_be_event)(Chardev *s, int event);
260     /* Return 0 if succeeded, 1 if failed */
261     int (*chr_machine_done)(Chardev *chr);
262 } ChardevClass;
263 
264 Chardev *qemu_chardev_new(const char *id, const char *typename,
265                           ChardevBackend *backend, Error **errp);
266 
267 extern int term_escape_char;
268 
269 GSource *qemu_chr_timeout_add_ms(Chardev *chr, guint ms,
270                                  GSourceFunc func, void *private);
271 
272 /* console.c */
273 void qemu_chr_parse_vc(QemuOpts *opts, ChardevBackend *backend, Error **errp);
274 
275 #endif
276