include/chardev/char.h

   1 #ifndef QEMU_CHAR_H
   2 #define QEMU_CHAR_H
   3
   4 #include "qapi/qapi-types-char.h"
   5 #include "qemu/bitmap.h"
   6 #include "qemu/thread.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     /* Whether the gcontext can be changed after calling
  51      * qemu_chr_be_update_read_handlers() */
  52     QEMU_CHAR_FEATURE_GCONTEXT,
  53
  54     QEMU_CHAR_FEATURE_LAST,
  55 } ChardevFeature;
  56
  57 #define qemu_chr_replay(chr) qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_REPLAY)
  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     /* used to coordinate the chardev-change special-case: */
  69     bool handover_yank_instance;
  70     GSource *gsource;
  71     GMainContext *gcontext;
  72     DECLARE_BITMAP(features, QEMU_CHAR_FEATURE_LAST);
  73 };
  74
  75 /**
  76  * qemu_chr_new_from_opts:
  77  * @opts: see qemu-config.c for a list of valid options
  78  * @context: the #GMainContext to be used at initialization time
  79  *
  80  * Create a new character backend from a QemuOpts list.
  81  *
  82  * Returns: on success: a new character backend
  83  *          otherwise:  NULL; @errp specifies the error
  84  *                            or left untouched in case of help option
  85  */
  86 Chardev *qemu_chr_new_from_opts(QemuOpts *opts,
  87                                 GMainContext *context,
  88                                 Error **errp);
  89
  90 /**
  91  * qemu_chr_parse_common:
  92  * @opts: the options that still need parsing
  93  * @backend: a new backend
  94  *
  95  * Parse the common options available to all character backends.
  96  */
  97 void qemu_chr_parse_common(QemuOpts *opts, ChardevCommon *backend);
  98
  99 /**
 100  * qemu_chr_parse_opts:
 101  *
 102  * Parse the options to the ChardevBackend struct.
 103  *
 104  * Returns: a new backend or NULL on error
 105  */
 106 ChardevBackend *qemu_chr_parse_opts(QemuOpts *opts,
 107                                     Error **errp);
 108
 109 /**
 110  * qemu_chr_new:
 111  * @label: the name of the backend
 112  * @filename: the URI
 113  * @context: the #GMainContext to be used at initialization time
 114  *
 115  * Create a new character backend from a URI.
 116  * Do not implicitly initialize a monitor if the chardev is muxed.
 117  *
 118  * Returns: a new character backend
 119  */
 120 Chardev *qemu_chr_new(const char *label, const char *filename,
 121                       GMainContext *context);
 122
 123 /**
 124  * qemu_chr_new_mux_mon:
 125  * @label: the name of the backend
 126  * @filename: the URI
 127  * @context: the #GMainContext to be used at initialization time
 128  *
 129  * Create a new character backend from a URI.
 130  * Implicitly initialize a monitor if the chardev is muxed.
 131  *
 132  * Returns: a new character backend
 133  */
 134 Chardev *qemu_chr_new_mux_mon(const char *label, const char *filename,
 135                               GMainContext *context);
 136
 137 /**
 138 * qemu_chr_change:
 139 * @opts: the new backend options
 140  *
 141  * Change an existing character backend
 142  */
 143 void qemu_chr_change(QemuOpts *opts, Error **errp);
 144
 145 /**
 146  * qemu_chr_cleanup:
 147  *
 148  * Delete all chardevs (when leaving qemu)
 149  */
 150 void qemu_chr_cleanup(void);
 151
 152 /**
 153  * qemu_chr_new_noreplay:
 154  * @label: the name of the backend
 155  * @filename: the URI
 156  * @permit_mux_mon: if chardev is muxed, initialize a monitor
 157  * @context: the #GMainContext to be used at initialization time
 158  *
 159  * Create a new character backend from a URI.
 160  * Character device communications are not written
 161  * into the replay log.
 162  *
 163  * Returns: a new character backend
 164  */
 165 Chardev *qemu_chr_new_noreplay(const char *label, const char *filename,
 166                                bool permit_mux_mon, GMainContext *context);
 167
 168 /**
 169  * qemu_chr_be_can_write:
 170  *
 171  * Determine how much data the front end can currently accept.  This function
 172  * returns the number of bytes the front end can accept.  If it returns 0, the
 173  * front end cannot receive data at the moment.  The function must be polled
 174  * to determine when data can be received.
 175  *
 176  * Returns: the number of bytes the front end can receive via @qemu_chr_be_write
 177  */
 178 int qemu_chr_be_can_write(Chardev *s);
 179
 180 /**
 181  * qemu_chr_be_write:
 182  * @buf: a buffer to receive data from the front end
 183  * @len: the number of bytes to receive from the front end
 184  *
 185  * Write data from the back end to the front end.  Before issuing this call,
 186  * the caller should call @qemu_chr_be_can_write to determine how much data
 187  * the front end can currently accept.
 188  */
 189 void qemu_chr_be_write(Chardev *s, const uint8_t *buf, int len);
 190
 191 /**
 192  * qemu_chr_be_write_impl:
 193  * @buf: a buffer to receive data from the front end
 194  * @len: the number of bytes to receive from the front end
 195  *
 196  * Implementation of back end writing. Used by replay module.
 197  */
 198 void qemu_chr_be_write_impl(Chardev *s, const uint8_t *buf, int len);
 199
 200 /**
 201  * qemu_chr_be_update_read_handlers:
 202  * @context: the gcontext that will be used to attach the watch sources
 203  *
 204  * Invoked when frontend read handlers are setup
 205  */
 206 void qemu_chr_be_update_read_handlers(Chardev *s,
 207                                       GMainContext *context);
 208
 209 /**
 210  * qemu_chr_be_event:
 211  * @event: the event to send
 212  *
 213  * Send an event from the back end to the front end.
 214  */
 215 void qemu_chr_be_event(Chardev *s, QEMUChrEvent event);
 216
 217 int qemu_chr_add_client(Chardev *s, int fd);
 218 Chardev *qemu_chr_find(const char *name);
 219
 220 bool qemu_chr_has_feature(Chardev *chr,
 221                           ChardevFeature feature);
 222 void qemu_chr_set_feature(Chardev *chr,
 223                           ChardevFeature feature);
 224 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename,
 225                                 bool permit_mux_mon);
 226 int qemu_chr_write(Chardev *s, const uint8_t *buf, int len, bool write_all);
 227 #define qemu_chr_write_all(s, buf, len) qemu_chr_write(s, buf, len, true)
 228 int qemu_chr_wait_connected(Chardev *chr, Error **errp);
 229
 230 #define TYPE_CHARDEV "chardev"
 231 OBJECT_DECLARE_TYPE(Chardev, ChardevClass, CHARDEV)
 232
 233 #define TYPE_CHARDEV_NULL "chardev-null"
 234 #define TYPE_CHARDEV_MUX "chardev-mux"
 235 #define TYPE_CHARDEV_RINGBUF "chardev-ringbuf"
 236 #define TYPE_CHARDEV_PTY "chardev-pty"
 237 #define TYPE_CHARDEV_CONSOLE "chardev-console"
 238 #define TYPE_CHARDEV_STDIO "chardev-stdio"
 239 #define TYPE_CHARDEV_PIPE "chardev-pipe"
 240 #define TYPE_CHARDEV_MEMORY "chardev-memory"
 241 #define TYPE_CHARDEV_PARALLEL "chardev-parallel"
 242 #define TYPE_CHARDEV_FILE "chardev-file"
 243 #define TYPE_CHARDEV_SERIAL "chardev-serial"
 244 #define TYPE_CHARDEV_SOCKET "chardev-socket"
 245 #define TYPE_CHARDEV_UDP "chardev-udp"
 246
 247 #define CHARDEV_IS_RINGBUF(chr) \
 248     object_dynamic_cast(OBJECT(chr), TYPE_CHARDEV_RINGBUF)
 249 #define CHARDEV_IS_PTY(chr) \
 250     object_dynamic_cast(OBJECT(chr), TYPE_CHARDEV_PTY)
 251
 252 struct ChardevClass {
 253     ObjectClass parent_class;
 254
 255     bool internal; /* TODO: eventually use TYPE_USER_CREATABLE */
 256     bool supports_yank;
 257
 258     /* parse command line options and populate QAPI @backend */
 259     void (*parse)(QemuOpts *opts, ChardevBackend *backend, Error **errp);
 260
 261     /* called after construction, open/starts the backend */
 262     void (*open)(Chardev *chr, ChardevBackend *backend,
 263                  bool *be_opened, Error **errp);
 264
 265     /* write buf to the backend */
 266     int (*chr_write)(Chardev *s, const uint8_t *buf, int len);
 267
 268     /*
 269      * Read from the backend (blocking). A typical front-end will instead rely
 270      * on chr_can_read/chr_read being called when polling/looping.
 271      */
 272     int (*chr_sync_read)(Chardev *s, const uint8_t *buf, int len);
 273
 274     /* create a watch on the backend */
 275     GSource *(*chr_add_watch)(Chardev *s, GIOCondition cond);
 276
 277     /* update the backend internal sources */
 278     void (*chr_update_read_handler)(Chardev *s);
 279
 280     /* send an ioctl to the backend */
 281     int (*chr_ioctl)(Chardev *s, int cmd, void *arg);
 282
 283     /* get ancillary-received fds during last read */
 284     int (*get_msgfds)(Chardev *s, int* fds, int num);
 285
 286     /* set ancillary fds to be sent with next write */
 287     int (*set_msgfds)(Chardev *s, int *fds, int num);
 288
 289     /* accept the given fd */
 290     int (*chr_add_client)(Chardev *chr, int fd);
 291
 292     /* wait for a connection */
 293     int (*chr_wait_connected)(Chardev *chr, Error **errp);
 294
 295     /* disconnect a connection */
 296     void (*chr_disconnect)(Chardev *chr);
 297
 298     /* called by frontend when it can read */
 299     void (*chr_accept_input)(Chardev *chr);
 300
 301     /* set terminal echo */
 302     void (*chr_set_echo)(Chardev *chr, bool echo);
 303
 304     /* notify the backend of frontend open state */
 305     void (*chr_set_fe_open)(Chardev *chr, int fe_open);
 306
 307     /* handle various events */
 308     void (*chr_be_event)(Chardev *s, QEMUChrEvent event);
 309 };
 310
 311 Chardev *qemu_chardev_new(const char *id, const char *typename,
 312                           ChardevBackend *backend, GMainContext *context,
 313                           Error **errp);
 314
 315 extern int term_escape_char;
 316
 317 GSource *qemu_chr_timeout_add_ms(Chardev *chr, guint ms,
 318                                  GSourceFunc func, void *private);
 319
 320 void suspend_mux_open(void);
 321 void resume_mux_open(void);
 322
 323 #endif