include/chardev/char.h

   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
  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 */
  26 } QEMUChrEvent;
  27
  28 #define CHR_READ_BUF_LEN 4096
  29
  30 typedef void IOEventHandler(void *opaque, int event);
  31
  32 typedef enum {
  33     /* Whether the chardev peer is able to close and
  34      * reopen the data channel, thus requiring support
  35      * for qemu_chr_wait_connected() to wait for a
  36      * valid connection */
  37     QEMU_CHAR_FEATURE_RECONNECTABLE,
  38     /* Whether it is possible to send/recv file descriptors
  39      * over the data channel */
  40     QEMU_CHAR_FEATURE_FD_PASS,
  41     /* Whether replay or record mode is enabled */
  42     QEMU_CHAR_FEATURE_REPLAY,
  43
  44     QEMU_CHAR_FEATURE_LAST,
  45 } ChardevFeature;
  46
  47 /* This is the backend as seen by frontend, the actual backend is
  48  * Chardev */
  49 typedef struct CharBackend {
  50     Chardev *chr;
  51     IOEventHandler *chr_event;
  52     IOCanReadHandler *chr_can_read;
  53     IOReadHandler *chr_read;
  54     void *opaque;
  55     int tag;
  56     int fe_open;
  57 } CharBackend;
  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     DECLARE_BITMAP(features, QEMU_CHAR_FEATURE_LAST);
  70 };
  71
  72 /**
  73  * @qemu_chr_new_from_opts:
  74  *
  75  * Create a new character backend from a QemuOpts list.
  76  *
  77  * @opts see qemu-config.c for a list of valid options
  78  *
  79  * Returns: a new character backend
  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_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 /**
 108  * @qemu_chr_fe_disconnect:
 109  *
 110  * Close a fd accpeted by character backend.
 111  * Without associated Chardev, do nothing.
 112  */
 113 void qemu_chr_fe_disconnect(CharBackend *be);
 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_fe_wait_connected:
 124  *
 125  * Wait for characted backend to be connected, return < 0 on error or
 126  * if no assicated Chardev.
 127  */
 128 int qemu_chr_fe_wait_connected(CharBackend *be, Error **errp);
 129
 130 /**
 131  * @qemu_chr_new_noreplay:
 132  *
 133  * Create a new character backend from a URI.
 134  * Character device communications are not written
 135  * into the replay log.
 136  *
 137  * @label the name of the backend
 138  * @filename the URI
 139  *
 140  * Returns: a new character backend
 141  */
 142 Chardev *qemu_chr_new_noreplay(const char *label, const char *filename);
 143
 144 /**
 145  * @qemu_chr_fe_set_echo:
 146  *
 147  * Ask the backend to override its normal echo setting.  This only really
 148  * applies to the stdio backend and is used by the QMP server such that you
 149  * can see what you type if you try to type QMP commands.
 150  * Without associated Chardev, do nothing.
 151  *
 152  * @echo true to enable echo, false to disable echo
 153  */
 154 void qemu_chr_fe_set_echo(CharBackend *be, bool echo);
 155
 156 /**
 157  * @qemu_chr_fe_set_open:
 158  *
 159  * Set character frontend open status.  This is an indication that the
 160  * front end is ready (or not) to begin doing I/O.
 161  * Without associated Chardev, do nothing.
 162  */
 163 void qemu_chr_fe_set_open(CharBackend *be, int fe_open);
 164
 165 /**
 166  * @qemu_chr_fe_printf:
 167  *
 168  * Write to a character backend using a printf style interface.  This
 169  * function is thread-safe. It does nothing without associated
 170  * Chardev.
 171  *
 172  * @fmt see #printf
 173  */
 174 void qemu_chr_fe_printf(CharBackend *be, const char *fmt, ...)
 175     GCC_FMT_ATTR(2, 3);
 176
 177 /**
 178  * @qemu_chr_fe_add_watch:
 179  *
 180  * If the backend is connected, create and add a #GSource that fires
 181  * when the given condition (typically G_IO_OUT|G_IO_HUP or G_IO_HUP)
 182  * is active; return the #GSource's tag.  If it is disconnected,
 183  * or without associated Chardev, return 0.
 184  *
 185  * @cond the condition to poll for
 186  * @func the function to call when the condition happens
 187  * @user_data the opaque pointer to pass to @func
 188  *
 189  * Returns: the source tag
 190  */
 191 guint qemu_chr_fe_add_watch(CharBackend *be, GIOCondition cond,
 192                             GIOFunc func, void *user_data);
 193
 194 /**
 195  * @qemu_chr_fe_write:
 196  *
 197  * Write data to a character backend from the front end.  This function
 198  * will send data from the front end to the back end.  This function
 199  * is thread-safe.
 200  *
 201  * @buf the data
 202  * @len the number of bytes to send
 203  *
 204  * Returns: the number of bytes consumed (0 if no assicated Chardev)
 205  */
 206 int qemu_chr_fe_write(CharBackend *be, const uint8_t *buf, int len);
 207
 208 /**
 209  * @qemu_chr_fe_write_all:
 210  *
 211  * Write data to a character backend from the front end.  This function will
 212  * send data from the front end to the back end.  Unlike @qemu_chr_fe_write,
 213  * this function will block if the back end cannot consume all of the data
 214  * attempted to be written.  This function is thread-safe.
 215  *
 216  * @buf the data
 217  * @len the number of bytes to send
 218  *
 219  * Returns: the number of bytes consumed (0 if no assicated Chardev)
 220  */
 221 int qemu_chr_fe_write_all(CharBackend *be, const uint8_t *buf, int len);
 222
 223 /**
 224  * @qemu_chr_fe_read_all:
 225  *
 226  * Read data to a buffer from the back end.
 227  *
 228  * @buf the data buffer
 229  * @len the number of bytes to read
 230  *
 231  * Returns: the number of bytes read (0 if no assicated Chardev)
 232  */
 233 int qemu_chr_fe_read_all(CharBackend *be, uint8_t *buf, int len);
 234
 235 /**
 236  * @qemu_chr_fe_ioctl:
 237  *
 238  * Issue a device specific ioctl to a backend.  This function is thread-safe.
 239  *
 240  * @cmd see CHR_IOCTL_*
 241  * @arg the data associated with @cmd
 242  *
 243  * Returns: if @cmd is not supported by the backend or there is no
 244  *          associated Chardev, -ENOTSUP, otherwise the return
 245  *          value depends on the semantics of @cmd
 246  */
 247 int qemu_chr_fe_ioctl(CharBackend *be, int cmd, void *arg);
 248
 249 /**
 250  * @qemu_chr_fe_get_msgfd:
 251  *
 252  * For backends capable of fd passing, return the latest file descriptor passed
 253  * by a client.
 254  *
 255  * Returns: -1 if fd passing isn't supported or there is no pending file
 256  *          descriptor.  If a file descriptor is returned, subsequent calls to
 257  *          this function will return -1 until a client sends a new file
 258  *          descriptor.
 259  */
 260 int qemu_chr_fe_get_msgfd(CharBackend *be);
 261
 262 /**
 263  * @qemu_chr_fe_get_msgfds:
 264  *
 265  * For backends capable of fd passing, return the number of file received
 266  * descriptors and fills the fds array up to num elements
 267  *
 268  * Returns: -1 if fd passing isn't supported or there are no pending file
 269  *          descriptors.  If file descriptors are returned, subsequent calls to
 270  *          this function will return -1 until a client sends a new set of file
 271  *          descriptors.
 272  */
 273 int qemu_chr_fe_get_msgfds(CharBackend *be, int *fds, int num);
 274
 275 /**
 276  * @qemu_chr_fe_set_msgfds:
 277  *
 278  * For backends capable of fd passing, set an array of fds to be passed with
 279  * the next send operation.
 280  * A subsequent call to this function before calling a write function will
 281  * result in overwriting the fd array with the new value without being send.
 282  * Upon writing the message the fd array is freed.
 283  *
 284  * Returns: -1 if fd passing isn't supported or no associated Chardev.
 285  */
 286 int qemu_chr_fe_set_msgfds(CharBackend *be, int *fds, int num);
 287
 288 /**
 289  * @qemu_chr_be_can_write:
 290  *
 291  * Determine how much data the front end can currently accept.  This function
 292  * returns the number of bytes the front end can accept.  If it returns 0, the
 293  * front end cannot receive data at the moment.  The function must be polled
 294  * to determine when data can be received.
 295  *
 296  * Returns: the number of bytes the front end can receive via @qemu_chr_be_write
 297  */
 298 int qemu_chr_be_can_write(Chardev *s);
 299
 300 /**
 301  * @qemu_chr_be_write:
 302  *
 303  * Write data from the back end to the front end.  Before issuing this call,
 304  * the caller should call @qemu_chr_be_can_write to determine how much data
 305  * the front end can currently accept.
 306  *
 307  * @buf a buffer to receive data from the front end
 308  * @len the number of bytes to receive from the front end
 309  */
 310 void qemu_chr_be_write(Chardev *s, uint8_t *buf, int len);
 311
 312 /**
 313  * @qemu_chr_be_write_impl:
 314  *
 315  * Implementation of back end writing. Used by replay module.
 316  *
 317  * @buf a buffer to receive data from the front end
 318  * @len the number of bytes to receive from the front end
 319  */
 320 void qemu_chr_be_write_impl(Chardev *s, uint8_t *buf, int len);
 321
 322 /**
 323  * @qemu_chr_be_event:
 324  *
 325  * Send an event from the back end to the front end.
 326  *
 327  * @event the event to send
 328  */
 329 void qemu_chr_be_event(Chardev *s, int event);
 330
 331 /**
 332  * @qemu_chr_fe_init:
 333  *
 334  * Initializes a front end for the given CharBackend and
 335  * Chardev. Call qemu_chr_fe_deinit() to remove the association and
 336  * release the driver.
 337  *
 338  * Returns: false on error.
 339  */
 340 bool qemu_chr_fe_init(CharBackend *b, Chardev *s, Error **errp);
 341
 342 /**
 343  * @qemu_chr_fe_get_driver:
 344  *
 345  * Returns the driver associated with a CharBackend or NULL if no
 346  * associated Chardev.
 347  */
 348 Chardev *qemu_chr_fe_get_driver(CharBackend *be);
 349
 350 /**
 351  * @qemu_chr_fe_deinit:
 352  *
 353  * Dissociate the CharBackend from the Chardev.
 354  *
 355  * Safe to call without associated Chardev.
 356  */
 357 void qemu_chr_fe_deinit(CharBackend *b);
 358
 359 /**
 360  * @qemu_chr_fe_set_handlers:
 361  * @b: a CharBackend
 362  * @fd_can_read: callback to get the amount of data the frontend may
 363  *               receive
 364  * @fd_read: callback to receive data from char
 365  * @fd_event: event callback
 366  * @opaque: an opaque pointer for the callbacks
 367  * @context: a main loop context or NULL for the default
 368  * @set_open: whether to call qemu_chr_fe_set_open() implicitely when
 369  * any of the handler is non-NULL
 370  *
 371  * Set the front end char handlers. The front end takes the focus if
 372  * any of the handler is non-NULL.
 373  *
 374  * Without associated Chardev, nothing is changed.
 375  */
 376 void qemu_chr_fe_set_handlers(CharBackend *b,
 377                               IOCanReadHandler *fd_can_read,
 378                               IOReadHandler *fd_read,
 379                               IOEventHandler *fd_event,
 380                               void *opaque,
 381                               GMainContext *context,
 382                               bool set_open);
 383
 384 /**
 385  * @qemu_chr_fe_take_focus:
 386  *
 387  * Take the focus (if the front end is muxed).
 388  *
 389  * Without associated Chardev, nothing is changed.
 390  */
 391 void qemu_chr_fe_take_focus(CharBackend *b);
 392
 393 void qemu_chr_fe_accept_input(CharBackend *be);
 394 int qemu_chr_add_client(Chardev *s, int fd);
 395 Chardev *qemu_chr_find(const char *name);
 396
 397 bool qemu_chr_has_feature(Chardev *chr,
 398                           ChardevFeature feature);
 399 void qemu_chr_set_feature(Chardev *chr,
 400                           ChardevFeature feature);
 401 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename);
 402 int qemu_chr_write_all(Chardev *s, const uint8_t *buf, int len);
 403 int qemu_chr_wait_connected(Chardev *chr, Error **errp);
 404
 405 #define TYPE_CHARDEV "chardev"
 406 #define CHARDEV(obj) OBJECT_CHECK(Chardev, (obj), TYPE_CHARDEV)
 407 #define CHARDEV_CLASS(klass) \
 408     OBJECT_CLASS_CHECK(ChardevClass, (klass), TYPE_CHARDEV)
 409 #define CHARDEV_GET_CLASS(obj) \
 410     OBJECT_GET_CLASS(ChardevClass, (obj), TYPE_CHARDEV)
 411
 412 #define TYPE_CHARDEV_NULL "chardev-null"
 413 #define TYPE_CHARDEV_MUX "chardev-mux"
 414 #define TYPE_CHARDEV_RINGBUF "chardev-ringbuf"
 415 #define TYPE_CHARDEV_PTY "chardev-pty"
 416 #define TYPE_CHARDEV_CONSOLE "chardev-console"
 417 #define TYPE_CHARDEV_STDIO "chardev-stdio"
 418 #define TYPE_CHARDEV_PIPE "chardev-pipe"
 419 #define TYPE_CHARDEV_MEMORY "chardev-memory"
 420 #define TYPE_CHARDEV_PARALLEL "chardev-parallel"
 421 #define TYPE_CHARDEV_FILE "chardev-file"
 422 #define TYPE_CHARDEV_SERIAL "chardev-serial"
 423 #define TYPE_CHARDEV_SOCKET "chardev-socket"
 424 #define TYPE_CHARDEV_UDP "chardev-udp"
 425
 426 #define CHARDEV_IS_RINGBUF(chr) \
 427     object_dynamic_cast(OBJECT(chr), TYPE_CHARDEV_RINGBUF)
 428 #define CHARDEV_IS_PTY(chr) \
 429     object_dynamic_cast(OBJECT(chr), TYPE_CHARDEV_PTY)
 430
 431 typedef struct ChardevClass {
 432     ObjectClass parent_class;
 433
 434     bool internal; /* TODO: eventually use TYPE_USER_CREATABLE */
 435     void (*parse)(QemuOpts *opts, ChardevBackend *backend, Error **errp);
 436
 437     void (*open)(Chardev *chr, ChardevBackend *backend,
 438                  bool *be_opened, Error **errp);
 439
 440     int (*chr_write)(Chardev *s, const uint8_t *buf, int len);
 441     int (*chr_sync_read)(Chardev *s, const uint8_t *buf, int len);
 442     GSource *(*chr_add_watch)(Chardev *s, GIOCondition cond);
 443     void (*chr_update_read_handler)(Chardev *s, GMainContext *context);
 444     int (*chr_ioctl)(Chardev *s, int cmd, void *arg);
 445     int (*get_msgfds)(Chardev *s, int* fds, int num);
 446     int (*set_msgfds)(Chardev *s, int *fds, int num);
 447     int (*chr_add_client)(Chardev *chr, int fd);
 448     int (*chr_wait_connected)(Chardev *chr, Error **errp);
 449     void (*chr_disconnect)(Chardev *chr);
 450     void (*chr_accept_input)(Chardev *chr);
 451     void (*chr_set_echo)(Chardev *chr, bool echo);
 452     void (*chr_set_fe_open)(Chardev *chr, int fe_open);
 453 } ChardevClass;
 454
 455 Chardev *qemu_chardev_new(const char *id, const char *typename,
 456                           ChardevBackend *backend, Error **errp);
 457
 458 extern int term_escape_char;
 459
 460 /* console.c */
 461 void qemu_chr_parse_vc(QemuOpts *opts, ChardevBackend *backend, Error **errp);
 462
 463 #endif