xref: /openbmc/qemu/include/chardev/char.h (revision c97d6d2c)
1 #ifndef QEMU_CHAR_H
2 #define QEMU_CHAR_H
3 
4 #include "qemu-common.h"
5 #include "qemu/option.h"
6 #include "qemu/main-loop.h"
7 #include "qemu/bitmap.h"
8 #include "qom/object.h"
9 
10 #define IAC_EOR 239
11 #define IAC_SE 240
12 #define IAC_NOP 241
13 #define IAC_BREAK 243
14 #define IAC_IP 244
15 #define IAC_SB 250
16 #define IAC 255
17 
18 /* character device */
19 typedef struct CharBackend CharBackend;
20 
21 typedef enum {
22     CHR_EVENT_BREAK, /* serial break char */
23     CHR_EVENT_OPENED, /* new connection established */
24     CHR_EVENT_MUX_IN, /* mux-focus was set to this terminal */
25     CHR_EVENT_MUX_OUT, /* mux-focus will move on */
26     CHR_EVENT_CLOSED /* connection closed */
27 } QEMUChrEvent;
28 
29 #define CHR_READ_BUF_LEN 4096
30 
31 typedef enum {
32     /* Whether the chardev peer is able to close and
33      * reopen the data channel, thus requiring support
34      * for qemu_chr_wait_connected() to wait for a
35      * valid connection */
36     QEMU_CHAR_FEATURE_RECONNECTABLE,
37     /* Whether it is possible to send/recv file descriptors
38      * over the data channel */
39     QEMU_CHAR_FEATURE_FD_PASS,
40     /* Whether replay or record mode is enabled */
41     QEMU_CHAR_FEATURE_REPLAY,
42 
43     QEMU_CHAR_FEATURE_LAST,
44 } ChardevFeature;
45 
46 #define qemu_chr_replay(chr) qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_REPLAY)
47 
48 struct Chardev {
49     Object parent_obj;
50 
51     QemuMutex chr_write_lock;
52     CharBackend *be;
53     char *label;
54     char *filename;
55     int logfd;
56     int be_open;
57     GSource *gsource;
58     GMainContext *gcontext;
59     DECLARE_BITMAP(features, QEMU_CHAR_FEATURE_LAST);
60 };
61 
62 /**
63  * @qemu_chr_new_from_opts:
64  *
65  * Create a new character backend from a QemuOpts list.
66  *
67  * @opts see qemu-config.c for a list of valid options
68  *
69  * Returns: on success: a new character backend
70  *          otherwise:  NULL; @errp specifies the error
71  *                            or left untouched in case of help option
72  */
73 Chardev *qemu_chr_new_from_opts(QemuOpts *opts,
74                                 Error **errp);
75 
76 /**
77  * @qemu_chr_parse_common:
78  *
79  * Parse the common options available to all character backends.
80  *
81  * @opts the options that still need parsing
82  * @backend a new backend
83  */
84 void qemu_chr_parse_common(QemuOpts *opts, ChardevCommon *backend);
85 
86 /**
87  * @qemu_chr_parse_opts:
88  *
89  * Parse the options to the ChardevBackend struct.
90  *
91  * Returns: a new backend or NULL on error
92  */
93 ChardevBackend *qemu_chr_parse_opts(QemuOpts *opts,
94                                     Error **errp);
95 
96 /**
97  * @qemu_chr_new:
98  *
99  * Create a new character backend from a URI.
100  *
101  * @label the name of the backend
102  * @filename the URI
103  *
104  * Returns: a new character backend
105  */
106 Chardev *qemu_chr_new(const char *label, const char *filename);
107 
108 /**
109  * @qemu_chr_change:
110  *
111  * Change an existing character backend
112  *
113  * @opts the new backend options
114  */
115 void qemu_chr_change(QemuOpts *opts, Error **errp);
116 
117 /**
118  * @qemu_chr_cleanup:
119  *
120  * Delete all chardevs (when leaving qemu)
121  */
122 void qemu_chr_cleanup(void);
123 
124 /**
125  * @qemu_chr_new_noreplay:
126  *
127  * Create a new character backend from a URI.
128  * Character device communications are not written
129  * into the replay log.
130  *
131  * @label the name of the backend
132  * @filename the URI
133  *
134  * Returns: a new character backend
135  */
136 Chardev *qemu_chr_new_noreplay(const char *label, const char *filename);
137 
138 /**
139  * @qemu_chr_be_can_write:
140  *
141  * Determine how much data the front end can currently accept.  This function
142  * returns the number of bytes the front end can accept.  If it returns 0, the
143  * front end cannot receive data at the moment.  The function must be polled
144  * to determine when data can be received.
145  *
146  * Returns: the number of bytes the front end can receive via @qemu_chr_be_write
147  */
148 int qemu_chr_be_can_write(Chardev *s);
149 
150 /**
151  * @qemu_chr_be_write:
152  *
153  * Write data from the back end to the front end.  Before issuing this call,
154  * the caller should call @qemu_chr_be_can_write to determine how much data
155  * the front end can currently accept.
156  *
157  * @buf a buffer to receive data from the front end
158  * @len the number of bytes to receive from the front end
159  */
160 void qemu_chr_be_write(Chardev *s, uint8_t *buf, int len);
161 
162 /**
163  * @qemu_chr_be_write_impl:
164  *
165  * Implementation of back end writing. Used by replay module.
166  *
167  * @buf a buffer to receive data from the front end
168  * @len the number of bytes to receive from the front end
169  */
170 void qemu_chr_be_write_impl(Chardev *s, uint8_t *buf, int len);
171 
172 /**
173  * @qemu_chr_be_update_read_handlers:
174  *
175  * Invoked when frontend read handlers are setup
176  *
177  * @context the gcontext that will be used to attach the watch sources
178  */
179 void qemu_chr_be_update_read_handlers(Chardev *s,
180                                       GMainContext *context);
181 
182 /**
183  * @qemu_chr_be_event:
184  *
185  * Send an event from the back end to the front end.
186  *
187  * @event the event to send
188  */
189 void qemu_chr_be_event(Chardev *s, int event);
190 
191 int qemu_chr_add_client(Chardev *s, int fd);
192 Chardev *qemu_chr_find(const char *name);
193 
194 bool qemu_chr_has_feature(Chardev *chr,
195                           ChardevFeature feature);
196 void qemu_chr_set_feature(Chardev *chr,
197                           ChardevFeature feature);
198 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename);
199 int qemu_chr_write(Chardev *s, const uint8_t *buf, int len, bool write_all);
200 #define qemu_chr_write_all(s, buf, len) qemu_chr_write(s, buf, len, true)
201 int qemu_chr_wait_connected(Chardev *chr, Error **errp);
202 
203 #define TYPE_CHARDEV "chardev"
204 #define CHARDEV(obj) OBJECT_CHECK(Chardev, (obj), TYPE_CHARDEV)
205 #define CHARDEV_CLASS(klass) \
206     OBJECT_CLASS_CHECK(ChardevClass, (klass), TYPE_CHARDEV)
207 #define CHARDEV_GET_CLASS(obj) \
208     OBJECT_GET_CLASS(ChardevClass, (obj), TYPE_CHARDEV)
209 
210 #define TYPE_CHARDEV_NULL "chardev-null"
211 #define TYPE_CHARDEV_MUX "chardev-mux"
212 #define TYPE_CHARDEV_RINGBUF "chardev-ringbuf"
213 #define TYPE_CHARDEV_PTY "chardev-pty"
214 #define TYPE_CHARDEV_CONSOLE "chardev-console"
215 #define TYPE_CHARDEV_STDIO "chardev-stdio"
216 #define TYPE_CHARDEV_PIPE "chardev-pipe"
217 #define TYPE_CHARDEV_MEMORY "chardev-memory"
218 #define TYPE_CHARDEV_PARALLEL "chardev-parallel"
219 #define TYPE_CHARDEV_FILE "chardev-file"
220 #define TYPE_CHARDEV_SERIAL "chardev-serial"
221 #define TYPE_CHARDEV_SOCKET "chardev-socket"
222 #define TYPE_CHARDEV_UDP "chardev-udp"
223 
224 #define CHARDEV_IS_RINGBUF(chr) \
225     object_dynamic_cast(OBJECT(chr), TYPE_CHARDEV_RINGBUF)
226 #define CHARDEV_IS_PTY(chr) \
227     object_dynamic_cast(OBJECT(chr), TYPE_CHARDEV_PTY)
228 
229 typedef struct ChardevClass {
230     ObjectClass parent_class;
231 
232     bool internal; /* TODO: eventually use TYPE_USER_CREATABLE */
233     void (*parse)(QemuOpts *opts, ChardevBackend *backend, Error **errp);
234 
235     void (*open)(Chardev *chr, ChardevBackend *backend,
236                  bool *be_opened, Error **errp);
237 
238     int (*chr_write)(Chardev *s, const uint8_t *buf, int len);
239     int (*chr_sync_read)(Chardev *s, const uint8_t *buf, int len);
240     GSource *(*chr_add_watch)(Chardev *s, GIOCondition cond);
241     void (*chr_update_read_handler)(Chardev *s);
242     int (*chr_ioctl)(Chardev *s, int cmd, void *arg);
243     int (*get_msgfds)(Chardev *s, int* fds, int num);
244     int (*set_msgfds)(Chardev *s, int *fds, int num);
245     int (*chr_add_client)(Chardev *chr, int fd);
246     int (*chr_wait_connected)(Chardev *chr, Error **errp);
247     void (*chr_disconnect)(Chardev *chr);
248     void (*chr_accept_input)(Chardev *chr);
249     void (*chr_set_echo)(Chardev *chr, bool echo);
250     void (*chr_set_fe_open)(Chardev *chr, int fe_open);
251     void (*chr_be_event)(Chardev *s, int event);
252 } ChardevClass;
253 
254 Chardev *qemu_chardev_new(const char *id, const char *typename,
255                           ChardevBackend *backend, Error **errp);
256 
257 extern int term_escape_char;
258 
259 /* console.c */
260 void qemu_chr_parse_vc(QemuOpts *opts, ChardevBackend *backend, Error **errp);
261 
262 #endif
263