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, counter = 10;
  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         if (!counter--) {
  93             break;
  94         }
  95     }
  96
  97     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_RECORD) {
  98         replay_char_read_all_save_buf(buf, offset);
  99     }
 100     return offset;
 101 }
 102
 103 int qemu_chr_fe_ioctl(CharBackend *be, int cmd, void *arg)
 104 {
 105     Chardev *s = be->chr;
 106     int res;
 107
 108     if (!s || !CHARDEV_GET_CLASS(s)->chr_ioctl || qemu_chr_replay(s)) {
 109         res = -ENOTSUP;
 110     } else {
 111         res = CHARDEV_GET_CLASS(s)->chr_ioctl(s, cmd, arg);
 112     }
 113
 114     return res;
 115 }
 116
 117 int qemu_chr_fe_get_msgfd(CharBackend *be)
 118 {
 119     Chardev *s = be->chr;
 120     int fd;
 121     int res = (qemu_chr_fe_get_msgfds(be, &fd, 1) == 1) ? fd : -1;
 122     if (s && qemu_chr_replay(s)) {
 123         error_report("Replay: get msgfd is not supported "
 124                      "for serial devices yet");
 125         exit(1);
 126     }
 127     return res;
 128 }
 129
 130 int qemu_chr_fe_get_msgfds(CharBackend *be, int *fds, int len)
 131 {
 132     Chardev *s = be->chr;
 133
 134     if (!s) {
 135         return -1;
 136     }
 137
 138     return CHARDEV_GET_CLASS(s)->get_msgfds ?
 139         CHARDEV_GET_CLASS(s)->get_msgfds(s, fds, len) : -1;
 140 }
 141
 142 int qemu_chr_fe_set_msgfds(CharBackend *be, int *fds, int num)
 143 {
 144     Chardev *s = be->chr;
 145
 146     if (!s) {
 147         return -1;
 148     }
 149
 150     return CHARDEV_GET_CLASS(s)->set_msgfds ?
 151         CHARDEV_GET_CLASS(s)->set_msgfds(s, fds, num) : -1;
 152 }
 153
 154 void qemu_chr_fe_accept_input(CharBackend *be)
 155 {
 156     Chardev *s = be->chr;
 157
 158     if (!s) {
 159         return;
 160     }
 161
 162     if (CHARDEV_GET_CLASS(s)->chr_accept_input) {
 163         CHARDEV_GET_CLASS(s)->chr_accept_input(s);
 164     }
 165     qemu_notify_event();
 166 }
 167
 168 void qemu_chr_fe_printf(CharBackend *be, const char *fmt, ...)
 169 {
 170     char buf[CHR_READ_BUF_LEN];
 171     va_list ap;
 172     va_start(ap, fmt);
 173     vsnprintf(buf, sizeof(buf), fmt, ap);
 174     /* XXX this blocks entire thread. Rewrite to use
 175      * qemu_chr_fe_write and background I/O callbacks */
 176     qemu_chr_fe_write_all(be, (uint8_t *)buf, strlen(buf));
 177     va_end(ap);
 178 }
 179
 180 Chardev *qemu_chr_fe_get_driver(CharBackend *be)
 181 {
 182     /* this is unsafe for the users that support chardev hotswap */
 183     assert(be->chr_be_change == NULL);
 184     return be->chr;
 185 }
 186
 187 bool qemu_chr_fe_backend_connected(CharBackend *be)
 188 {
 189     return !!be->chr;
 190 }
 191
 192 bool qemu_chr_fe_backend_open(CharBackend *be)
 193 {
 194     return be->chr && be->chr->be_open;
 195 }
 196
 197 bool qemu_chr_fe_init(CharBackend *b, Chardev *s, Error **errp)
 198 {
 199     int tag = 0;
 200
 201     if (CHARDEV_IS_MUX(s)) {
 202         MuxChardev *d = MUX_CHARDEV(s);
 203
 204         if (d->mux_cnt >= MAX_MUX) {
 205             goto unavailable;
 206         }
 207
 208         d->backends[d->mux_cnt] = b;
 209         tag = d->mux_cnt++;
 210     } else if (s->be) {
 211         goto unavailable;
 212     } else {
 213         s->be = b;
 214     }
 215
 216     b->fe_open = false;
 217     b->tag = tag;
 218     b->chr = s;
 219     return true;
 220
 221 unavailable:
 222     error_setg(errp, QERR_DEVICE_IN_USE, s->label);
 223     return false;
 224 }
 225
 226 void qemu_chr_fe_deinit(CharBackend *b, bool del)
 227 {
 228     assert(b);
 229
 230     if (b->chr) {
 231         qemu_chr_fe_set_handlers(b, NULL, NULL, NULL, NULL, NULL, NULL, true);
 232         if (b->chr->be == b) {
 233             b->chr->be = NULL;
 234         }
 235         if (CHARDEV_IS_MUX(b->chr)) {
 236             MuxChardev *d = MUX_CHARDEV(b->chr);
 237             d->backends[b->tag] = NULL;
 238         }
 239         if (del) {
 240             object_unparent(OBJECT(b->chr));
 241         }
 242         b->chr = NULL;
 243     }
 244 }
 245
 246 void qemu_chr_fe_set_handlers(CharBackend *b,
 247                               IOCanReadHandler *fd_can_read,
 248                               IOReadHandler *fd_read,
 249                               IOEventHandler *fd_event,
 250                               BackendChangeHandler *be_change,
 251                               void *opaque,
 252                               GMainContext *context,
 253                               bool set_open)
 254 {
 255     Chardev *s;
 256     int fe_open;
 257
 258     s = b->chr;
 259     if (!s) {
 260         return;
 261     }
 262
 263     if (!opaque && !fd_can_read && !fd_read && !fd_event) {
 264         fe_open = 0;
 265         remove_fd_in_watch(s);
 266     } else {
 267         fe_open = 1;
 268     }
 269     b->chr_can_read = fd_can_read;
 270     b->chr_read = fd_read;
 271     b->chr_event = fd_event;
 272     b->chr_be_change = be_change;
 273     b->opaque = opaque;
 274
 275     qemu_chr_be_update_read_handlers(s, context);
 276
 277     if (set_open) {
 278         qemu_chr_fe_set_open(b, fe_open);
 279     }
 280
 281     if (fe_open) {
 282         qemu_chr_fe_take_focus(b);
 283         /* We're connecting to an already opened device, so let's make sure we
 284            also get the open event */
 285         if (s->be_open) {
 286             qemu_chr_be_event(s, CHR_EVENT_OPENED);
 287         }
 288     }
 289
 290     if (CHARDEV_IS_MUX(s)) {
 291         mux_chr_set_handlers(s, context);
 292     }
 293 }
 294
 295 void qemu_chr_fe_take_focus(CharBackend *b)
 296 {
 297     if (!b->chr) {
 298         return;
 299     }
 300
 301     if (CHARDEV_IS_MUX(b->chr)) {
 302         mux_set_focus(b->chr, b->tag);
 303     }
 304 }
 305
 306 int qemu_chr_fe_wait_connected(CharBackend *be, Error **errp)
 307 {
 308     if (!be->chr) {
 309         error_setg(errp, "missing associated backend");
 310         return -1;
 311     }
 312
 313     return qemu_chr_wait_connected(be->chr, errp);
 314 }
 315
 316 void qemu_chr_fe_set_echo(CharBackend *be, bool echo)
 317 {
 318     Chardev *chr = be->chr;
 319
 320     if (chr && CHARDEV_GET_CLASS(chr)->chr_set_echo) {
 321         CHARDEV_GET_CLASS(chr)->chr_set_echo(chr, echo);
 322     }
 323 }
 324
 325 void qemu_chr_fe_set_open(CharBackend *be, int fe_open)
 326 {
 327     Chardev *chr = be->chr;
 328
 329     if (!chr) {
 330         return;
 331     }
 332
 333     if (be->fe_open == fe_open) {
 334         return;
 335     }
 336     be->fe_open = fe_open;
 337     if (CHARDEV_GET_CLASS(chr)->chr_set_fe_open) {
 338         CHARDEV_GET_CLASS(chr)->chr_set_fe_open(chr, fe_open);
 339     }
 340 }
 341
 342 guint qemu_chr_fe_add_watch(CharBackend *be, GIOCondition cond,
 343                             GIOFunc func, void *user_data)
 344 {
 345     Chardev *s = be->chr;
 346     GSource *src;
 347     guint tag;
 348
 349     if (!s || CHARDEV_GET_CLASS(s)->chr_add_watch == NULL) {
 350         return 0;
 351     }
 352
 353     src = CHARDEV_GET_CLASS(s)->chr_add_watch(s, cond);
 354     if (!src) {
 355         return 0;
 356     }
 357
 358     g_source_set_callback(src, (GSourceFunc)func, user_data, NULL);
 359     tag = g_source_attach(src, s->gcontext);
 360     g_source_unref(src);
 361
 362     return tag;
 363 }
 364
 365 void qemu_chr_fe_disconnect(CharBackend *be)
 366 {
 367     Chardev *chr = be->chr;
 368
 369     if (chr && CHARDEV_GET_CLASS(chr)->chr_disconnect) {
 370         CHARDEV_GET_CLASS(chr)->chr_disconnect(chr);
 371     }
 372 }