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/char-mux.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                 goto unavailable;
 203             }
 204
 205             d->backends[d->mux_cnt] = b;
 206             tag = d->mux_cnt++;
 207         } else if (s->be) {
 208             goto unavailable;
 209         } else {
 210             s->be = b;
 211         }
 212     }
 213
 214     b->fe_open = false;
 215     b->tag = tag;
 216     b->chr = s;
 217     return true;
 218
 219 unavailable:
 220     error_setg(errp, QERR_DEVICE_IN_USE, s->label);
 221     return false;
 222 }
 223
 224 void qemu_chr_fe_deinit(CharBackend *b, bool del)
 225 {
 226     assert(b);
 227
 228     if (b->chr) {
 229         qemu_chr_fe_set_handlers(b, NULL, NULL, NULL, NULL, NULL, NULL, true);
 230         if (b->chr->be == b) {
 231             b->chr->be = NULL;
 232         }
 233         if (CHARDEV_IS_MUX(b->chr)) {
 234             MuxChardev *d = MUX_CHARDEV(b->chr);
 235             d->backends[b->tag] = NULL;
 236         }
 237         if (del) {
 238             Object *obj = OBJECT(b->chr);
 239             if (obj->parent) {
 240                 object_unparent(obj);
 241             } else {
 242                 object_unref(obj);
 243             }
 244         }
 245         b->chr = NULL;
 246     }
 247 }
 248
 249 void qemu_chr_fe_set_handlers(CharBackend *b,
 250                               IOCanReadHandler *fd_can_read,
 251                               IOReadHandler *fd_read,
 252                               IOEventHandler *fd_event,
 253                               BackendChangeHandler *be_change,
 254                               void *opaque,
 255                               GMainContext *context,
 256                               bool set_open)
 257 {
 258     Chardev *s;
 259     int fe_open;
 260
 261     s = b->chr;
 262     if (!s) {
 263         return;
 264     }
 265
 266     if (!opaque && !fd_can_read && !fd_read && !fd_event) {
 267         fe_open = 0;
 268         remove_fd_in_watch(s);
 269     } else {
 270         fe_open = 1;
 271     }
 272     b->chr_can_read = fd_can_read;
 273     b->chr_read = fd_read;
 274     b->chr_event = fd_event;
 275     b->chr_be_change = be_change;
 276     b->opaque = opaque;
 277
 278     qemu_chr_be_update_read_handlers(s, context);
 279
 280     if (set_open) {
 281         qemu_chr_fe_set_open(b, fe_open);
 282     }
 283
 284     if (fe_open) {
 285         qemu_chr_fe_take_focus(b);
 286         /* We're connecting to an already opened device, so let's make sure we
 287            also get the open event */
 288         if (s->be_open) {
 289             qemu_chr_be_event(s, CHR_EVENT_OPENED);
 290         }
 291     }
 292
 293     if (CHARDEV_IS_MUX(s)) {
 294         mux_chr_set_handlers(s, context);
 295     }
 296 }
 297
 298 void qemu_chr_fe_take_focus(CharBackend *b)
 299 {
 300     if (!b->chr) {
 301         return;
 302     }
 303
 304     if (CHARDEV_IS_MUX(b->chr)) {
 305         mux_set_focus(b->chr, b->tag);
 306     }
 307 }
 308
 309 int qemu_chr_fe_wait_connected(CharBackend *be, Error **errp)
 310 {
 311     if (!be->chr) {
 312         error_setg(errp, "missing associated backend");
 313         return -1;
 314     }
 315
 316     return qemu_chr_wait_connected(be->chr, errp);
 317 }
 318
 319 void qemu_chr_fe_set_echo(CharBackend *be, bool echo)
 320 {
 321     Chardev *chr = be->chr;
 322
 323     if (chr && CHARDEV_GET_CLASS(chr)->chr_set_echo) {
 324         CHARDEV_GET_CLASS(chr)->chr_set_echo(chr, echo);
 325     }
 326 }
 327
 328 void qemu_chr_fe_set_open(CharBackend *be, int fe_open)
 329 {
 330     Chardev *chr = be->chr;
 331
 332     if (!chr) {
 333         return;
 334     }
 335
 336     if (be->fe_open == fe_open) {
 337         return;
 338     }
 339     be->fe_open = fe_open;
 340     if (CHARDEV_GET_CLASS(chr)->chr_set_fe_open) {
 341         CHARDEV_GET_CLASS(chr)->chr_set_fe_open(chr, fe_open);
 342     }
 343 }
 344
 345 guint qemu_chr_fe_add_watch(CharBackend *be, GIOCondition cond,
 346                             GIOFunc func, void *user_data)
 347 {
 348     Chardev *s = be->chr;
 349     GSource *src;
 350     guint tag;
 351
 352     if (!s || CHARDEV_GET_CLASS(s)->chr_add_watch == NULL) {
 353         return 0;
 354     }
 355
 356     src = CHARDEV_GET_CLASS(s)->chr_add_watch(s, cond);
 357     if (!src) {
 358         return 0;
 359     }
 360
 361     g_source_set_callback(src, (GSourceFunc)func, user_data, NULL);
 362     tag = g_source_attach(src, s->gcontext);
 363     g_source_unref(src);
 364
 365     return tag;
 366 }
 367
 368 void qemu_chr_fe_disconnect(CharBackend *be)
 369 {
 370     Chardev *chr = be->chr;
 371
 372     if (chr && CHARDEV_GET_CLASS(chr)->chr_disconnect) {
 373         CHARDEV_GET_CLASS(chr)->chr_disconnect(chr);
 374     }
 375 }