chardev/char-fe.c

   1 /*
   2  * QEMU System Emulator
   3  *
   4  * Copyright (c) 2003-2008 Fabrice Bellard
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24 #include "qemu/osdep.h"
  25 #include "qemu/error-report.h"
  26 #include "qapi/error.h"
  27 #include "qapi/qmp/qerror.h"
  28 #include "sysemu/replay.h"
  29
  30 #include "chardev/char-fe.h"
  31 #include "chardev/char-io.h"
  32 #include "chardev-internal.h"
  33
  34 int qemu_chr_fe_write(CharBackend *be, const uint8_t *buf, int len)
  35 {
  36     Chardev *s = be->chr;
  37
  38     if (!s) {
  39         return 0;
  40     }
  41
  42     return qemu_chr_write(s, buf, len, false);
  43 }
  44
  45 int qemu_chr_fe_write_all(CharBackend *be, const uint8_t *buf, int len)
  46 {
  47     Chardev *s = be->chr;
  48
  49     if (!s) {
  50         return 0;
  51     }
  52
  53     return qemu_chr_write(s, buf, len, true);
  54 }
  55
  56 int qemu_chr_fe_read_all(CharBackend *be, uint8_t *buf, int len)
  57 {
  58     Chardev *s = be->chr;
  59     int offset = 0;
  60     int res;
  61
  62     if (!s || !CHARDEV_GET_CLASS(s)->chr_sync_read) {
  63         return 0;
  64     }
  65
  66     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_PLAY) {
  67         return replay_char_read_all_load(buf);
  68     }
  69
  70     while (offset < len) {
  71     retry:
  72         res = CHARDEV_GET_CLASS(s)->chr_sync_read(s, buf + offset,
  73                                                   len - offset);
  74         if (res == -1 && errno == EAGAIN) {
  75             g_usleep(100);
  76             goto retry;
  77         }
  78
  79         if (res == 0) {
  80             break;
  81         }
  82
  83         if (res < 0) {
  84             if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_RECORD) {
  85                 replay_char_read_all_save_error(res);
  86             }
  87             return res;
  88         }
  89
  90         offset += res;
  91     }
  92
  93     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_RECORD) {
  94         replay_char_read_all_save_buf(buf, offset);
  95     }
  96     return offset;
  97 }
  98
  99 int qemu_chr_fe_ioctl(CharBackend *be, int cmd, void *arg)
 100 {
 101     Chardev *s = be->chr;
 102     int res;
 103
 104     if (!s || !CHARDEV_GET_CLASS(s)->chr_ioctl || qemu_chr_replay(s)) {
 105         res = -ENOTSUP;
 106     } else {
 107         res = CHARDEV_GET_CLASS(s)->chr_ioctl(s, cmd, arg);
 108     }
 109
 110     return res;
 111 }
 112
 113 int qemu_chr_fe_get_msgfd(CharBackend *be)
 114 {
 115     Chardev *s = be->chr;
 116     int fd;
 117     int res = (qemu_chr_fe_get_msgfds(be, &fd, 1) == 1) ? fd : -1;
 118     if (s && qemu_chr_replay(s)) {
 119         error_report("Replay: get msgfd is not supported "
 120                      "for serial devices yet");
 121         exit(1);
 122     }
 123     return res;
 124 }
 125
 126 int qemu_chr_fe_get_msgfds(CharBackend *be, int *fds, int len)
 127 {
 128     Chardev *s = be->chr;
 129
 130     if (!s) {
 131         return -1;
 132     }
 133
 134     return CHARDEV_GET_CLASS(s)->get_msgfds ?
 135         CHARDEV_GET_CLASS(s)->get_msgfds(s, fds, len) : -1;
 136 }
 137
 138 int qemu_chr_fe_set_msgfds(CharBackend *be, int *fds, int num)
 139 {
 140     Chardev *s = be->chr;
 141
 142     if (!s) {
 143         return -1;
 144     }
 145
 146     return CHARDEV_GET_CLASS(s)->set_msgfds ?
 147         CHARDEV_GET_CLASS(s)->set_msgfds(s, fds, num) : -1;
 148 }
 149
 150 void qemu_chr_fe_accept_input(CharBackend *be)
 151 {
 152     Chardev *s = be->chr;
 153
 154     if (!s) {
 155         return;
 156     }
 157
 158     if (CHARDEV_GET_CLASS(s)->chr_accept_input) {
 159         CHARDEV_GET_CLASS(s)->chr_accept_input(s);
 160     }
 161     qemu_notify_event();
 162 }
 163
 164 void qemu_chr_fe_printf(CharBackend *be, const char *fmt, ...)
 165 {
 166     char buf[CHR_READ_BUF_LEN];
 167     va_list ap;
 168     va_start(ap, fmt);
 169     vsnprintf(buf, sizeof(buf), fmt, ap);
 170     /* XXX this blocks entire thread. Rewrite to use
 171      * qemu_chr_fe_write and background I/O callbacks */
 172     qemu_chr_fe_write_all(be, (uint8_t *)buf, strlen(buf));
 173     va_end(ap);
 174 }
 175
 176 Chardev *qemu_chr_fe_get_driver(CharBackend *be)
 177 {
 178     /* this is unsafe for the users that support chardev hotswap */
 179     assert(be->chr_be_change == NULL);
 180     return be->chr;
 181 }
 182
 183 bool qemu_chr_fe_backend_connected(CharBackend *be)
 184 {
 185     return !!be->chr;
 186 }
 187
 188 bool qemu_chr_fe_backend_open(CharBackend *be)
 189 {
 190     return be->chr && be->chr->be_open;
 191 }
 192
 193 bool qemu_chr_fe_init(CharBackend *b, Chardev *s, Error **errp)
 194 {
 195     int tag = 0;
 196
 197     if (s) {
 198         if (CHARDEV_IS_MUX(s)) {
 199             MuxChardev *d = MUX_CHARDEV(s);
 200
 201             if (d->mux_cnt >= MAX_MUX) {
 202                 error_setg(errp,
 203                            "too many uses of multiplexed chardev '%s'"
 204                            " (maximum is " stringify(MAX_MUX) ")",
 205                            s->label);
 206                 return false;
 207             }
 208
 209             d->backends[d->mux_cnt] = b;
 210             tag = d->mux_cnt++;
 211         } else if (s->be) {
 212             error_setg(errp, "chardev '%s' is already in use", s->label);
 213             return false;
 214         } else {
 215             s->be = b;
 216         }
 217     }
 218
 219     b->fe_is_open = false;
 220     b->tag = tag;
 221     b->chr = s;
 222     return true;
 223 }
 224
 225 void qemu_chr_fe_deinit(CharBackend *b, bool del)
 226 {
 227     assert(b);
 228
 229     if (b->chr) {
 230         qemu_chr_fe_set_handlers(b, NULL, NULL, NULL, NULL, NULL, NULL, true);
 231         if (b->chr->be == b) {
 232             b->chr->be = NULL;
 233         }
 234         if (CHARDEV_IS_MUX(b->chr)) {
 235             MuxChardev *d = MUX_CHARDEV(b->chr);
 236             d->backends[b->tag] = NULL;
 237         }
 238         if (del) {
 239             Object *obj = OBJECT(b->chr);
 240             if (obj->parent) {
 241                 object_unparent(obj);
 242             } else {
 243                 object_unref(obj);
 244             }
 245         }
 246         b->chr = NULL;
 247     }
 248 }
 249
 250 void qemu_chr_fe_set_handlers_full(CharBackend *b,
 251                                    IOCanReadHandler *fd_can_read,
 252                                    IOReadHandler *fd_read,
 253                                    IOEventHandler *fd_event,
 254                                    BackendChangeHandler *be_change,
 255                                    void *opaque,
 256                                    GMainContext *context,
 257                                    bool set_open,
 258                                    bool sync_state)
 259 {
 260     Chardev *s;
 261     bool fe_open;
 262
 263     s = b->chr;
 264     if (!s) {
 265         return;
 266     }
 267
 268     if (!opaque && !fd_can_read && !fd_read && !fd_event) {
 269         fe_open = false;
 270         remove_fd_in_watch(s);
 271     } else {
 272         fe_open = true;
 273     }
 274     b->chr_can_read = fd_can_read;
 275     b->chr_read = fd_read;
 276     b->chr_event = fd_event;
 277     b->chr_be_change = be_change;
 278     b->opaque = opaque;
 279
 280     qemu_chr_be_update_read_handlers(s, context);
 281
 282     if (set_open) {
 283         qemu_chr_fe_set_open(b, fe_open);
 284     }
 285
 286     if (fe_open) {
 287         qemu_chr_fe_take_focus(b);
 288         /* We're connecting to an already opened device, so let's make sure we
 289            also get the open event */
 290         if (sync_state && s->be_open) {
 291             qemu_chr_be_event(s, CHR_EVENT_OPENED);
 292         }
 293     }
 294 }
 295
 296 void qemu_chr_fe_set_handlers(CharBackend *b,
 297                               IOCanReadHandler *fd_can_read,
 298                               IOReadHandler *fd_read,
 299                               IOEventHandler *fd_event,
 300                               BackendChangeHandler *be_change,
 301                               void *opaque,
 302                               GMainContext *context,
 303                               bool set_open)
 304 {
 305     qemu_chr_fe_set_handlers_full(b, fd_can_read, fd_read, fd_event, be_change,
 306                                   opaque, context, set_open,
 307                                   true);
 308 }
 309
 310 void qemu_chr_fe_take_focus(CharBackend *b)
 311 {
 312     if (!b->chr) {
 313         return;
 314     }
 315
 316     if (CHARDEV_IS_MUX(b->chr)) {
 317         mux_set_focus(b->chr, b->tag);
 318     }
 319 }
 320
 321 int qemu_chr_fe_wait_connected(CharBackend *be, Error **errp)
 322 {
 323     if (!be->chr) {
 324         error_setg(errp, "missing associated backend");
 325         return -1;
 326     }
 327
 328     return qemu_chr_wait_connected(be->chr, errp);
 329 }
 330
 331 void qemu_chr_fe_set_echo(CharBackend *be, bool echo)
 332 {
 333     Chardev *chr = be->chr;
 334
 335     if (chr && CHARDEV_GET_CLASS(chr)->chr_set_echo) {
 336         CHARDEV_GET_CLASS(chr)->chr_set_echo(chr, echo);
 337     }
 338 }
 339
 340 void qemu_chr_fe_set_open(CharBackend *be, bool is_open)
 341 {
 342     Chardev *chr = be->chr;
 343
 344     if (!chr) {
 345         return;
 346     }
 347
 348     if (be->fe_is_open == is_open) {
 349         return;
 350     }
 351     be->fe_is_open = is_open;
 352     if (CHARDEV_GET_CLASS(chr)->chr_set_fe_open) {
 353         CHARDEV_GET_CLASS(chr)->chr_set_fe_open(chr, is_open);
 354     }
 355 }
 356
 357 guint qemu_chr_fe_add_watch(CharBackend *be, GIOCondition cond,
 358                             FEWatchFunc func, void *user_data)
 359 {
 360     Chardev *s = be->chr;
 361     GSource *src;
 362     guint tag;
 363
 364     if (!s || CHARDEV_GET_CLASS(s)->chr_add_watch == NULL) {
 365         return 0;
 366     }
 367
 368     src = CHARDEV_GET_CLASS(s)->chr_add_watch(s, cond);
 369     if (!src) {
 370         return 0;
 371     }
 372
 373 #pragma GCC diagnostic ignored "-Wcast-function-type"
 374     g_source_set_callback(src, (GSourceFunc)func, user_data, NULL);
 375     tag = g_source_attach(src, s->gcontext);
 376     g_source_unref(src);
 377
 378     return tag;
 379 }
 380
 381 void qemu_chr_fe_disconnect(CharBackend *be)
 382 {
 383     Chardev *chr = be->chr;
 384
 385     if (chr && CHARDEV_GET_CLASS(chr)->chr_disconnect) {
 386         CHARDEV_GET_CLASS(chr)->chr_disconnect(chr);
 387     }
 388 }