include/sysemu/char.h

   1 #ifndef QEMU_CHAR_H
   2 #define QEMU_CHAR_H
   3
   4 #include "qemu-common.h"
   5 #include "qemu/queue.h"
   6 #include "qemu/option.h"
   7 #include "qemu/config-file.h"
   8 #include "block/aio.h"
   9 #include "qapi/qmp/qobject.h"
  10 #include "qapi/qmp/qstring.h"
  11 #include "qemu/main-loop.h"
  12 #include "qemu/bitmap.h"
  13
  14 /* character device */
  15
  16 typedef enum {
  17     CHR_EVENT_BREAK, /* serial break char */
  18     CHR_EVENT_OPENED, /* new connection established */
  19     CHR_EVENT_MUX_IN, /* mux-focus was set to this terminal */
  20     CHR_EVENT_MUX_OUT, /* mux-focus will move on */
  21     CHR_EVENT_CLOSED /* connection closed */
  22 } QEMUChrEvent;
  23
  24
  25 #define CHR_IOCTL_SERIAL_SET_PARAMS   1
  26 typedef struct {
  27     int speed;
  28     int parity;
  29     int data_bits;
  30     int stop_bits;
  31 } QEMUSerialSetParams;
  32
  33 #define CHR_IOCTL_SERIAL_SET_BREAK    2
  34
  35 #define CHR_IOCTL_PP_READ_DATA        3
  36 #define CHR_IOCTL_PP_WRITE_DATA       4
  37 #define CHR_IOCTL_PP_READ_CONTROL     5
  38 #define CHR_IOCTL_PP_WRITE_CONTROL    6
  39 #define CHR_IOCTL_PP_READ_STATUS      7
  40 #define CHR_IOCTL_PP_EPP_READ_ADDR    8
  41 #define CHR_IOCTL_PP_EPP_READ         9
  42 #define CHR_IOCTL_PP_EPP_WRITE_ADDR  10
  43 #define CHR_IOCTL_PP_EPP_WRITE       11
  44 #define CHR_IOCTL_PP_DATA_DIR        12
  45
  46 struct ParallelIOArg {
  47     void *buffer;
  48     int count;
  49 };
  50
  51 #define CHR_IOCTL_SERIAL_SET_TIOCM   13
  52 #define CHR_IOCTL_SERIAL_GET_TIOCM   14
  53
  54 #define CHR_TIOCM_CTS   0x020
  55 #define CHR_TIOCM_CAR   0x040
  56 #define CHR_TIOCM_DSR   0x100
  57 #define CHR_TIOCM_RI    0x080
  58 #define CHR_TIOCM_DTR   0x002
  59 #define CHR_TIOCM_RTS   0x004
  60
  61 typedef void IOEventHandler(void *opaque, int event);
  62
  63 typedef enum {
  64     /* Whether the chardev peer is able to close and
  65      * reopen the data channel, thus requiring support
  66      * for qemu_chr_wait_connected() to wait for a
  67      * valid connection */
  68     QEMU_CHAR_FEATURE_RECONNECTABLE,
  69     /* Whether it is possible to send/recv file descriptors
  70      * over the data channel */
  71     QEMU_CHAR_FEATURE_FD_PASS,
  72     /* Whether replay or record mode is enabled */
  73     QEMU_CHAR_FEATURE_REPLAY,
  74
  75     QEMU_CHAR_FEATURE_LAST,
  76 } CharDriverFeature;
  77
  78 /* This is the backend as seen by frontend, the actual backend is
  79  * Chardev */
  80 typedef struct CharBackend {
  81     Chardev *chr;
  82     IOEventHandler *chr_event;
  83     IOCanReadHandler *chr_can_read;
  84     IOReadHandler *chr_read;
  85     void *opaque;
  86     int tag;
  87     int fe_open;
  88 } CharBackend;
  89
  90 typedef struct CharDriver CharDriver;
  91
  92 struct Chardev {
  93     const CharDriver *driver;
  94     QemuMutex chr_write_lock;
  95     CharBackend *be;
  96     char *label;
  97     char *filename;
  98     int logfd;
  99     int be_open;
 100     guint fd_in_tag;
 101     DECLARE_BITMAP(features, QEMU_CHAR_FEATURE_LAST);
 102     QTAILQ_ENTRY(Chardev) next;
 103 };
 104
 105 /**
 106  * qemu_chr_alloc:
 107  * @backend: the common backend config
 108  * @errp: pointer to a NULL-initialized error object
 109  *
 110  * Allocate and initialize a new Chardev.
 111  *
 112  * Returns: a newly allocated Chardev, or NULL on error.
 113  */
 114 Chardev *qemu_chr_alloc(const CharDriver *driver,
 115                         ChardevCommon *backend, Error **errp);
 116
 117 /**
 118  * @qemu_chr_new_from_opts:
 119  *
 120  * Create a new character backend from a QemuOpts list.
 121  *
 122  * @opts see qemu-config.c for a list of valid options
 123  *
 124  * Returns: a new character backend
 125  */
 126 Chardev *qemu_chr_new_from_opts(QemuOpts *opts,
 127                                 Error **errp);
 128
 129 /**
 130  * @qemu_chr_parse_common:
 131  *
 132  * Parse the common options available to all character backends.
 133  *
 134  * @opts the options that still need parsing
 135  * @backend a new backend
 136  */
 137 void qemu_chr_parse_common(QemuOpts *opts, ChardevCommon *backend);
 138
 139 /**
 140  * @qemu_chr_new:
 141  *
 142  * Create a new character backend from a URI.
 143  *
 144  * @label the name of the backend
 145  * @filename the URI
 146  *
 147  * Returns: a new character backend
 148  */
 149 Chardev *qemu_chr_new(const char *label, const char *filename);
 150
 151
 152 /**
 153  * @qemu_chr_fe_disconnect:
 154  *
 155  * Close a fd accpeted by character backend.
 156  * Without associated CharDriver, do nothing.
 157  */
 158 void qemu_chr_fe_disconnect(CharBackend *be);
 159
 160 /**
 161  * @qemu_chr_cleanup:
 162  *
 163  * Delete all chardevs (when leaving qemu)
 164  */
 165 void qemu_chr_cleanup(void);
 166
 167 /**
 168  * @qemu_chr_fe_wait_connected:
 169  *
 170  * Wait for characted backend to be connected, return < 0 on error or
 171  * if no assicated CharDriver.
 172  */
 173 int qemu_chr_fe_wait_connected(CharBackend *be, Error **errp);
 174
 175 /**
 176  * @qemu_chr_new_noreplay:
 177  *
 178  * Create a new character backend from a URI.
 179  * Character device communications are not written
 180  * into the replay log.
 181  *
 182  * @label the name of the backend
 183  * @filename the URI
 184  *
 185  * Returns: a new character backend
 186  */
 187 Chardev *qemu_chr_new_noreplay(const char *label, const char *filename);
 188
 189 /**
 190  * @qemu_chr_delete:
 191  *
 192  * Destroy a character backend and remove it from the list of
 193  * identified character backends.
 194  */
 195 void qemu_chr_delete(Chardev *chr);
 196
 197 /**
 198  * @qemu_chr_free:
 199  *
 200  * Destroy a character backend.
 201  */
 202 void qemu_chr_free(Chardev *chr);
 203
 204 /**
 205  * @qemu_chr_fe_set_echo:
 206  *
 207  * Ask the backend to override its normal echo setting.  This only really
 208  * applies to the stdio backend and is used by the QMP server such that you
 209  * can see what you type if you try to type QMP commands.
 210  * Without associated CharDriver, do nothing.
 211  *
 212  * @echo true to enable echo, false to disable echo
 213  */
 214 void qemu_chr_fe_set_echo(CharBackend *be, bool echo);
 215
 216 /**
 217  * @qemu_chr_fe_set_open:
 218  *
 219  * Set character frontend open status.  This is an indication that the
 220  * front end is ready (or not) to begin doing I/O.
 221  * Without associated CharDriver, do nothing.
 222  */
 223 void qemu_chr_fe_set_open(CharBackend *be, int fe_open);
 224
 225 /**
 226  * @qemu_chr_fe_printf:
 227  *
 228  * Write to a character backend using a printf style interface.  This
 229  * function is thread-safe. It does nothing without associated
 230  * CharDriver.
 231  *
 232  * @fmt see #printf
 233  */
 234 void qemu_chr_fe_printf(CharBackend *be, const char *fmt, ...)
 235     GCC_FMT_ATTR(2, 3);
 236
 237 /**
 238  * @qemu_chr_fe_add_watch:
 239  *
 240  * If the backend is connected, create and add a #GSource that fires
 241  * when the given condition (typically G_IO_OUT|G_IO_HUP or G_IO_HUP)
 242  * is active; return the #GSource's tag.  If it is disconnected,
 243  * or without associated CharDriver, return 0.
 244  *
 245  * @cond the condition to poll for
 246  * @func the function to call when the condition happens
 247  * @user_data the opaque pointer to pass to @func
 248  *
 249  * Returns: the source tag
 250  */
 251 guint qemu_chr_fe_add_watch(CharBackend *be, GIOCondition cond,
 252                             GIOFunc func, void *user_data);
 253
 254 /**
 255  * @qemu_chr_fe_write:
 256  *
 257  * Write data to a character backend from the front end.  This function
 258  * will send data from the front end to the back end.  This function
 259  * is thread-safe.
 260  *
 261  * @buf the data
 262  * @len the number of bytes to send
 263  *
 264  * Returns: the number of bytes consumed (0 if no assicated CharDriver)
 265  */
 266 int qemu_chr_fe_write(CharBackend *be, const uint8_t *buf, int len);
 267
 268 /**
 269  * @qemu_chr_fe_write_all:
 270  *
 271  * Write data to a character backend from the front end.  This function will
 272  * send data from the front end to the back end.  Unlike @qemu_chr_fe_write,
 273  * this function will block if the back end cannot consume all of the data
 274  * attempted to be written.  This function is thread-safe.
 275  *
 276  * @buf the data
 277  * @len the number of bytes to send
 278  *
 279  * Returns: the number of bytes consumed (0 if no assicated CharDriver)
 280  */
 281 int qemu_chr_fe_write_all(CharBackend *be, const uint8_t *buf, int len);
 282
 283 /**
 284  * @qemu_chr_fe_read_all:
 285  *
 286  * Read data to a buffer from the back end.
 287  *
 288  * @buf the data buffer
 289  * @len the number of bytes to read
 290  *
 291  * Returns: the number of bytes read (0 if no assicated CharDriver)
 292  */
 293 int qemu_chr_fe_read_all(CharBackend *be, uint8_t *buf, int len);
 294
 295 /**
 296  * @qemu_chr_fe_ioctl:
 297  *
 298  * Issue a device specific ioctl to a backend.  This function is thread-safe.
 299  *
 300  * @cmd see CHR_IOCTL_*
 301  * @arg the data associated with @cmd
 302  *
 303  * Returns: if @cmd is not supported by the backend or there is no
 304  *          associated CharDriver, -ENOTSUP, otherwise the return
 305  *          value depends on the semantics of @cmd
 306  */
 307 int qemu_chr_fe_ioctl(CharBackend *be, int cmd, void *arg);
 308
 309 /**
 310  * @qemu_chr_fe_get_msgfd:
 311  *
 312  * For backends capable of fd passing, return the latest file descriptor passed
 313  * by a client.
 314  *
 315  * Returns: -1 if fd passing isn't supported or there is no pending file
 316  *          descriptor.  If a file descriptor is returned, subsequent calls to
 317  *          this function will return -1 until a client sends a new file
 318  *          descriptor.
 319  */
 320 int qemu_chr_fe_get_msgfd(CharBackend *be);
 321
 322 /**
 323  * @qemu_chr_fe_get_msgfds:
 324  *
 325  * For backends capable of fd passing, return the number of file received
 326  * descriptors and fills the fds array up to num elements
 327  *
 328  * Returns: -1 if fd passing isn't supported or there are no pending file
 329  *          descriptors.  If file descriptors are returned, subsequent calls to
 330  *          this function will return -1 until a client sends a new set of file
 331  *          descriptors.
 332  */
 333 int qemu_chr_fe_get_msgfds(CharBackend *be, int *fds, int num);
 334
 335 /**
 336  * @qemu_chr_fe_set_msgfds:
 337  *
 338  * For backends capable of fd passing, set an array of fds to be passed with
 339  * the next send operation.
 340  * A subsequent call to this function before calling a write function will
 341  * result in overwriting the fd array with the new value without being send.
 342  * Upon writing the message the fd array is freed.
 343  *
 344  * Returns: -1 if fd passing isn't supported or no associated CharDriver.
 345  */
 346 int qemu_chr_fe_set_msgfds(CharBackend *be, int *fds, int num);
 347
 348 /**
 349  * @qemu_chr_be_can_write:
 350  *
 351  * Determine how much data the front end can currently accept.  This function
 352  * returns the number of bytes the front end can accept.  If it returns 0, the
 353  * front end cannot receive data at the moment.  The function must be polled
 354  * to determine when data can be received.
 355  *
 356  * Returns: the number of bytes the front end can receive via @qemu_chr_be_write
 357  */
 358 int qemu_chr_be_can_write(Chardev *s);
 359
 360 /**
 361  * @qemu_chr_be_write:
 362  *
 363  * Write data from the back end to the front end.  Before issuing this call,
 364  * the caller should call @qemu_chr_be_can_write to determine how much data
 365  * the front end can currently accept.
 366  *
 367  * @buf a buffer to receive data from the front end
 368  * @len the number of bytes to receive from the front end
 369  */
 370 void qemu_chr_be_write(Chardev *s, uint8_t *buf, int len);
 371
 372 /**
 373  * @qemu_chr_be_write_impl:
 374  *
 375  * Implementation of back end writing. Used by replay module.
 376  *
 377  * @buf a buffer to receive data from the front end
 378  * @len the number of bytes to receive from the front end
 379  */
 380 void qemu_chr_be_write_impl(Chardev *s, uint8_t *buf, int len);
 381
 382 /**
 383  * @qemu_chr_be_event:
 384  *
 385  * Send an event from the back end to the front end.
 386  *
 387  * @event the event to send
 388  */
 389 void qemu_chr_be_event(Chardev *s, int event);
 390
 391 /**
 392  * @qemu_chr_fe_init:
 393  *
 394  * Initializes a front end for the given CharBackend and
 395  * CharDriver. Call qemu_chr_fe_deinit() to remove the association and
 396  * release the driver.
 397  *
 398  * Returns: false on error.
 399  */
 400 bool qemu_chr_fe_init(CharBackend *b, Chardev *s, Error **errp);
 401
 402 /**
 403  * @qemu_chr_fe_get_driver:
 404  *
 405  * Returns the driver associated with a CharBackend or NULL if no
 406  * associated CharDriver.
 407  */
 408 Chardev *qemu_chr_fe_get_driver(CharBackend *be);
 409
 410 /**
 411  * @qemu_chr_fe_deinit:
 412  *
 413  * Dissociate the CharBackend from the CharDriver.
 414  *
 415  * Safe to call without associated CharDriver.
 416  */
 417 void qemu_chr_fe_deinit(CharBackend *b);
 418
 419 /**
 420  * @qemu_chr_fe_set_handlers:
 421  * @b: a CharBackend
 422  * @fd_can_read: callback to get the amount of data the frontend may
 423  *               receive
 424  * @fd_read: callback to receive data from char
 425  * @fd_event: event callback
 426  * @opaque: an opaque pointer for the callbacks
 427  * @context: a main loop context or NULL for the default
 428  * @set_open: whether to call qemu_chr_fe_set_open() implicitely when
 429  * any of the handler is non-NULL
 430  *
 431  * Set the front end char handlers. The front end takes the focus if
 432  * any of the handler is non-NULL.
 433  *
 434  * Without associated CharDriver, nothing is changed.
 435  */
 436 void qemu_chr_fe_set_handlers(CharBackend *b,
 437                               IOCanReadHandler *fd_can_read,
 438                               IOReadHandler *fd_read,
 439                               IOEventHandler *fd_event,
 440                               void *opaque,
 441                               GMainContext *context,
 442                               bool set_open);
 443
 444 /**
 445  * @qemu_chr_fe_take_focus:
 446  *
 447  * Take the focus (if the front end is muxed).
 448  *
 449  * Without associated CharDriver, nothing is changed.
 450  */
 451 void qemu_chr_fe_take_focus(CharBackend *b);
 452
 453 void qemu_chr_be_generic_open(Chardev *s);
 454 void qemu_chr_fe_accept_input(CharBackend *be);
 455 int qemu_chr_add_client(Chardev *s, int fd);
 456 Chardev *qemu_chr_find(const char *name);
 457
 458 /**
 459  * @qemu_chr_get_kind:
 460  *
 461  * Returns the kind of char backend, or -1 if unspecified.
 462  */
 463 ChardevBackendKind qemu_chr_get_kind(const Chardev *chr);
 464
 465 static inline bool qemu_chr_is_ringbuf(const Chardev *chr)
 466 {
 467     return qemu_chr_get_kind(chr) == CHARDEV_BACKEND_KIND_RINGBUF ||
 468         qemu_chr_get_kind(chr) == CHARDEV_BACKEND_KIND_MEMORY;
 469 }
 470
 471 bool qemu_chr_has_feature(Chardev *chr,
 472                           CharDriverFeature feature);
 473 void qemu_chr_set_feature(Chardev *chr,
 474                           CharDriverFeature feature);
 475 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename);
 476
 477 struct CharDriver {
 478     ChardevBackendKind kind;
 479     const char *alias;
 480     void (*parse)(QemuOpts *opts, ChardevBackend *backend, Error **errp);
 481     Chardev *(*create)(const CharDriver *driver,
 482                        const char *id,
 483                        ChardevBackend *backend,
 484                        ChardevReturn *ret, bool *be_opened,
 485                        Error **errp);
 486     size_t instance_size;
 487
 488     int (*chr_write)(struct Chardev *s, const uint8_t *buf, int len);
 489     int (*chr_sync_read)(struct Chardev *s,
 490                          const uint8_t *buf, int len);
 491     GSource *(*chr_add_watch)(struct Chardev *s, GIOCondition cond);
 492     void (*chr_update_read_handler)(struct Chardev *s,
 493                                     GMainContext *context);
 494     int (*chr_ioctl)(struct Chardev *s, int cmd, void *arg);
 495     int (*get_msgfds)(struct Chardev *s, int* fds, int num);
 496     int (*set_msgfds)(struct Chardev *s, int *fds, int num);
 497     int (*chr_add_client)(struct Chardev *chr, int fd);
 498     int (*chr_wait_connected)(struct Chardev *chr, Error **errp);
 499     void (*chr_free)(struct Chardev *chr);
 500     void (*chr_disconnect)(struct Chardev *chr);
 501     void (*chr_accept_input)(struct Chardev *chr);
 502     void (*chr_set_echo)(struct Chardev *chr, bool echo);
 503     void (*chr_set_fe_open)(struct Chardev *chr, int fe_open);
 504 };
 505
 506 void register_char_driver(const CharDriver *driver);
 507
 508 extern int term_escape_char;
 509
 510 /* console.c */
 511 void qemu_chr_parse_vc(QemuOpts *opts, ChardevBackend *backend, Error **errp);
 512
 513 #endif