xref: /openbmc/qemu/include/chardev/char.h (revision 80adf54e)
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     DECLARE_BITMAP(features, QEMU_CHAR_FEATURE_LAST);
59 };
60 
61 /**
62  * @qemu_chr_new_from_opts:
63  *
64  * Create a new character backend from a QemuOpts list.
65  *
66  * @opts see qemu-config.c for a list of valid options
67  *
68  * Returns: on success: a new character backend
69  *          otherwise:  NULL; @errp specifies the error
70  *                            or left untouched in case of help option
71  */
72 Chardev *qemu_chr_new_from_opts(QemuOpts *opts,
73                                 Error **errp);
74 
75 /**
76  * @qemu_chr_parse_common:
77  *
78  * Parse the common options available to all character backends.
79  *
80  * @opts the options that still need parsing
81  * @backend a new backend
82  */
83 void qemu_chr_parse_common(QemuOpts *opts, ChardevCommon *backend);
84 
85 /**
86  * @qemu_chr_parse_opts:
87  *
88  * Parse the options to the ChardevBackend struct.
89  *
90  * Returns: a new backend or NULL on error
91  */
92 ChardevBackend *qemu_chr_parse_opts(QemuOpts *opts,
93                                     Error **errp);
94 
95 /**
96  * @qemu_chr_new:
97  *
98  * Create a new character backend from a URI.
99  *
100  * @label the name of the backend
101  * @filename the URI
102  *
103  * Returns: a new character backend
104  */
105 Chardev *qemu_chr_new(const char *label, const char *filename);
106 
107 /**
108  * @qemu_chr_change:
109  *
110  * Change an existing character backend
111  *
112  * @opts the new backend options
113  */
114 void qemu_chr_change(QemuOpts *opts, Error **errp);
115 
116 /**
117  * @qemu_chr_cleanup:
118  *
119  * Delete all chardevs (when leaving qemu)
120  */
121 void qemu_chr_cleanup(void);
122 
123 /**
124  * @qemu_chr_new_noreplay:
125  *
126  * Create a new character backend from a URI.
127  * Character device communications are not written
128  * into the replay log.
129  *
130  * @label the name of the backend
131  * @filename the URI
132  *
133  * Returns: a new character backend
134  */
135 Chardev *qemu_chr_new_noreplay(const char *label, const char *filename);
136 
137 /**
138  * @qemu_chr_be_can_write:
139  *
140  * Determine how much data the front end can currently accept.  This function
141  * returns the number of bytes the front end can accept.  If it returns 0, the
142  * front end cannot receive data at the moment.  The function must be polled
143  * to determine when data can be received.
144  *
145  * Returns: the number of bytes the front end can receive via @qemu_chr_be_write
146  */
147 int qemu_chr_be_can_write(Chardev *s);
148 
149 /**
150  * @qemu_chr_be_write:
151  *
152  * Write data from the back end to the front end.  Before issuing this call,
153  * the caller should call @qemu_chr_be_can_write to determine how much data
154  * the front end can currently accept.
155  *
156  * @buf a buffer to receive data from the front end
157  * @len the number of bytes to receive from the front end
158  */
159 void qemu_chr_be_write(Chardev *s, uint8_t *buf, int len);
160 
161 /**
162  * @qemu_chr_be_write_impl:
163  *
164  * Implementation of back end writing. Used by replay module.
165  *
166  * @buf a buffer to receive data from the front end
167  * @len the number of bytes to receive from the front end
168  */
169 void qemu_chr_be_write_impl(Chardev *s, uint8_t *buf, int len);
170 
171 /**
172  * @qemu_chr_be_event:
173  *
174  * Send an event from the back end to the front end.
175  *
176  * @event the event to send
177  */
178 void qemu_chr_be_event(Chardev *s, int event);
179 
180 int qemu_chr_add_client(Chardev *s, int fd);
181 Chardev *qemu_chr_find(const char *name);
182 
183 bool qemu_chr_has_feature(Chardev *chr,
184                           ChardevFeature feature);
185 void qemu_chr_set_feature(Chardev *chr,
186                           ChardevFeature feature);
187 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename);
188 int qemu_chr_write(Chardev *s, const uint8_t *buf, int len, bool write_all);
189 #define qemu_chr_write_all(s, buf, len) qemu_chr_write(s, buf, len, true)
190 int qemu_chr_wait_connected(Chardev *chr, Error **errp);
191 
192 #define TYPE_CHARDEV "chardev"
193 #define CHARDEV(obj) OBJECT_CHECK(Chardev, (obj), TYPE_CHARDEV)
194 #define CHARDEV_CLASS(klass) \
195     OBJECT_CLASS_CHECK(ChardevClass, (klass), TYPE_CHARDEV)
196 #define CHARDEV_GET_CLASS(obj) \
197     OBJECT_GET_CLASS(ChardevClass, (obj), TYPE_CHARDEV)
198 
199 #define TYPE_CHARDEV_NULL "chardev-null"
200 #define TYPE_CHARDEV_MUX "chardev-mux"
201 #define TYPE_CHARDEV_RINGBUF "chardev-ringbuf"
202 #define TYPE_CHARDEV_PTY "chardev-pty"
203 #define TYPE_CHARDEV_CONSOLE "chardev-console"
204 #define TYPE_CHARDEV_STDIO "chardev-stdio"
205 #define TYPE_CHARDEV_PIPE "chardev-pipe"
206 #define TYPE_CHARDEV_MEMORY "chardev-memory"
207 #define TYPE_CHARDEV_PARALLEL "chardev-parallel"
208 #define TYPE_CHARDEV_FILE "chardev-file"
209 #define TYPE_CHARDEV_SERIAL "chardev-serial"
210 #define TYPE_CHARDEV_SOCKET "chardev-socket"
211 #define TYPE_CHARDEV_UDP "chardev-udp"
212 
213 #define CHARDEV_IS_RINGBUF(chr) \
214     object_dynamic_cast(OBJECT(chr), TYPE_CHARDEV_RINGBUF)
215 #define CHARDEV_IS_PTY(chr) \
216     object_dynamic_cast(OBJECT(chr), TYPE_CHARDEV_PTY)
217 
218 typedef struct ChardevClass {
219     ObjectClass parent_class;
220 
221     bool internal; /* TODO: eventually use TYPE_USER_CREATABLE */
222     void (*parse)(QemuOpts *opts, ChardevBackend *backend, Error **errp);
223 
224     void (*open)(Chardev *chr, ChardevBackend *backend,
225                  bool *be_opened, Error **errp);
226 
227     int (*chr_write)(Chardev *s, const uint8_t *buf, int len);
228     int (*chr_sync_read)(Chardev *s, const uint8_t *buf, int len);
229     GSource *(*chr_add_watch)(Chardev *s, GIOCondition cond);
230     void (*chr_update_read_handler)(Chardev *s, GMainContext *context);
231     int (*chr_ioctl)(Chardev *s, int cmd, void *arg);
232     int (*get_msgfds)(Chardev *s, int* fds, int num);
233     int (*set_msgfds)(Chardev *s, int *fds, int num);
234     int (*chr_add_client)(Chardev *chr, int fd);
235     int (*chr_wait_connected)(Chardev *chr, Error **errp);
236     void (*chr_disconnect)(Chardev *chr);
237     void (*chr_accept_input)(Chardev *chr);
238     void (*chr_set_echo)(Chardev *chr, bool echo);
239     void (*chr_set_fe_open)(Chardev *chr, int fe_open);
240 } ChardevClass;
241 
242 Chardev *qemu_chardev_new(const char *id, const char *typename,
243                           ChardevBackend *backend, Error **errp);
244 
245 extern int term_escape_char;
246 
247 /* console.c */
248 void qemu_chr_parse_vc(QemuOpts *opts, ChardevBackend *backend, Error **errp);
249 
250 #endif
251