chardev/char-pty.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
  25 #include "qemu/osdep.h"
  26 #include "qapi/error.h"
  27 #include "chardev/char.h"
  28 #include "io/channel-file.h"
  29 #include "qemu/sockets.h"
  30 #include "qemu/error-report.h"
  31 #include "qemu/module.h"
  32 #include "qemu/qemu-print.h"
  33
  34 #include "chardev/char-io.h"
  35 #include "qom/object.h"
  36
  37 struct PtyChardev {
  38     Chardev parent;
  39     QIOChannel *ioc;
  40     int read_bytes;
  41
  42     int connected;
  43     GSource *timer_src;
  44 };
  45 typedef struct PtyChardev PtyChardev;
  46
  47 DECLARE_INSTANCE_CHECKER(PtyChardev, PTY_CHARDEV,
  48                          TYPE_CHARDEV_PTY)
  49
  50 static void pty_chr_state(Chardev *chr, int connected);
  51
  52 static void pty_chr_timer_cancel(PtyChardev *s)
  53 {
  54     if (s->timer_src) {
  55         g_source_destroy(s->timer_src);
  56         g_source_unref(s->timer_src);
  57         s->timer_src = NULL;
  58     }
  59 }
  60
  61 static gboolean pty_chr_timer(gpointer opaque)
  62 {
  63     struct Chardev *chr = CHARDEV(opaque);
  64     PtyChardev *s = PTY_CHARDEV(opaque);
  65
  66     pty_chr_timer_cancel(s);
  67     if (!s->connected) {
  68         /* Next poll ... */
  69         qemu_chr_be_update_read_handlers(chr, chr->gcontext);
  70     }
  71     return FALSE;
  72 }
  73
  74 static void pty_chr_rearm_timer(Chardev *chr, int ms)
  75 {
  76     PtyChardev *s = PTY_CHARDEV(chr);
  77     char *name;
  78
  79     pty_chr_timer_cancel(s);
  80     name = g_strdup_printf("pty-timer-%s", chr->label);
  81     s->timer_src = qemu_chr_timeout_add_ms(chr, ms, pty_chr_timer, chr);
  82     g_source_set_name(s->timer_src, name);
  83     g_free(name);
  84 }
  85
  86 static void pty_chr_update_read_handler(Chardev *chr)
  87 {
  88     PtyChardev *s = PTY_CHARDEV(chr);
  89     GPollFD pfd;
  90     int rc;
  91     QIOChannelFile *fioc = QIO_CHANNEL_FILE(s->ioc);
  92
  93     pfd.fd = fioc->fd;
  94     pfd.events = G_IO_OUT;
  95     pfd.revents = 0;
  96     do {
  97         rc = g_poll(&pfd, 1, 0);
  98     } while (rc == -1 && errno == EINTR);
  99     assert(rc >= 0);
 100
 101     if (pfd.revents & G_IO_HUP) {
 102         pty_chr_state(chr, 0);
 103     } else {
 104         pty_chr_state(chr, 1);
 105     }
 106 }
 107
 108 static int char_pty_chr_write(Chardev *chr, const uint8_t *buf, int len)
 109 {
 110     PtyChardev *s = PTY_CHARDEV(chr);
 111
 112     if (!s->connected) {
 113         return len;
 114     }
 115     return io_channel_send(s->ioc, buf, len);
 116 }
 117
 118 static GSource *pty_chr_add_watch(Chardev *chr, GIOCondition cond)
 119 {
 120     PtyChardev *s = PTY_CHARDEV(chr);
 121     if (!s->connected) {
 122         return NULL;
 123     }
 124     return qio_channel_create_watch(s->ioc, cond);
 125 }
 126
 127 static int pty_chr_read_poll(void *opaque)
 128 {
 129     Chardev *chr = CHARDEV(opaque);
 130     PtyChardev *s = PTY_CHARDEV(opaque);
 131
 132     s->read_bytes = qemu_chr_be_can_write(chr);
 133     return s->read_bytes;
 134 }
 135
 136 static gboolean pty_chr_read(QIOChannel *chan, GIOCondition cond, void *opaque)
 137 {
 138     Chardev *chr = CHARDEV(opaque);
 139     PtyChardev *s = PTY_CHARDEV(opaque);
 140     gsize len;
 141     uint8_t buf[CHR_READ_BUF_LEN];
 142     ssize_t ret;
 143
 144     len = sizeof(buf);
 145     if (len > s->read_bytes) {
 146         len = s->read_bytes;
 147     }
 148     if (len == 0) {
 149         return TRUE;
 150     }
 151     ret = qio_channel_read(s->ioc, (char *)buf, len, NULL);
 152     if (ret <= 0) {
 153         pty_chr_state(chr, 0);
 154         return FALSE;
 155     } else {
 156         pty_chr_state(chr, 1);
 157         qemu_chr_be_write(chr, buf, ret);
 158     }
 159     return TRUE;
 160 }
 161
 162 static void pty_chr_state(Chardev *chr, int connected)
 163 {
 164     PtyChardev *s = PTY_CHARDEV(chr);
 165
 166     if (!connected) {
 167         remove_fd_in_watch(chr);
 168         s->connected = 0;
 169         /* (re-)connect poll interval for idle guests: once per second.
 170          * We check more frequently in case the guests sends data to
 171          * the virtual device linked to our pty. */
 172         pty_chr_rearm_timer(chr, 1000);
 173     } else {
 174         pty_chr_timer_cancel(s);
 175         if (!s->connected) {
 176             s->connected = 1;
 177             qemu_chr_be_event(chr, CHR_EVENT_OPENED);
 178         }
 179         if (!chr->gsource) {
 180             chr->gsource = io_add_watch_poll(chr, s->ioc,
 181                                                pty_chr_read_poll,
 182                                                pty_chr_read,
 183                                                chr, chr->gcontext);
 184         }
 185     }
 186 }
 187
 188 static void char_pty_finalize(Object *obj)
 189 {
 190     Chardev *chr = CHARDEV(obj);
 191     PtyChardev *s = PTY_CHARDEV(obj);
 192
 193     pty_chr_state(chr, 0);
 194     object_unref(OBJECT(s->ioc));
 195     pty_chr_timer_cancel(s);
 196     qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
 197 }
 198
 199 #if defined HAVE_PTY_H
 200 # include <pty.h>
 201 #elif defined CONFIG_BSD
 202 # include <termios.h>
 203 # if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
 204 #  include <libutil.h>
 205 # else
 206 #  include <util.h>
 207 # endif
 208 #elif defined CONFIG_SOLARIS
 209 # include <termios.h>
 210 # include <stropts.h>
 211 #else
 212 # include <termios.h>
 213 #endif
 214
 215 #ifdef __sun__
 216
 217 #if !defined(HAVE_OPENPTY)
 218 /* Once illumos has openpty(), this is going to be removed. */
 219 static int openpty(int *amaster, int *aslave, char *name,
 220                    struct termios *termp, struct winsize *winp)
 221 {
 222     const char *slave;
 223     int mfd = -1, sfd = -1;
 224
 225     *amaster = *aslave = -1;
 226
 227     mfd = open("/dev/ptmx", O_RDWR | O_NOCTTY);
 228     if (mfd < 0) {
 229         goto err;
 230     }
 231
 232     if (grantpt(mfd) == -1 || unlockpt(mfd) == -1) {
 233         goto err;
 234     }
 235
 236     if ((slave = ptsname(mfd)) == NULL) {
 237         goto err;
 238     }
 239
 240     if ((sfd = open(slave, O_RDONLY | O_NOCTTY)) == -1) {
 241         goto err;
 242     }
 243
 244     if (ioctl(sfd, I_PUSH, "ptem") == -1 ||
 245         (termp != NULL && tcgetattr(sfd, termp) < 0)) {
 246         goto err;
 247     }
 248
 249     *amaster = mfd;
 250     *aslave = sfd;
 251
 252     if (winp) {
 253         ioctl(sfd, TIOCSWINSZ, winp);
 254     }
 255
 256     return 0;
 257
 258 err:
 259     if (sfd != -1) {
 260         close(sfd);
 261     }
 262     close(mfd);
 263     return -1;
 264 }
 265 #endif
 266
 267 static void cfmakeraw (struct termios *termios_p)
 268 {
 269     termios_p->c_iflag &=
 270         ~(IGNBRK | BRKINT | PARMRK | ISTRIP | INLCR | IGNCR | ICRNL | IXON);
 271     termios_p->c_oflag &= ~OPOST;
 272     termios_p->c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
 273     termios_p->c_cflag &= ~(CSIZE | PARENB);
 274     termios_p->c_cflag |= CS8;
 275
 276     termios_p->c_cc[VMIN] = 0;
 277     termios_p->c_cc[VTIME] = 0;
 278 }
 279 #endif
 280
 281 /* like openpty() but also makes it raw; return master fd */
 282 static int qemu_openpty_raw(int *aslave, char *pty_name)
 283 {
 284     int amaster;
 285     struct termios tty;
 286 #if defined(__OpenBSD__) || defined(__DragonFly__)
 287     char pty_buf[PATH_MAX];
 288 #define q_ptsname(x) pty_buf
 289 #else
 290     char *pty_buf = NULL;
 291 #define q_ptsname(x) ptsname(x)
 292 #endif
 293
 294     if (openpty(&amaster, aslave, pty_buf, NULL, NULL) < 0) {
 295         return -1;
 296     }
 297
 298     /* Set raw attributes on the pty. */
 299     tcgetattr(*aslave, &tty);
 300     cfmakeraw(&tty);
 301     tcsetattr(*aslave, TCSAFLUSH, &tty);
 302
 303     if (pty_name) {
 304         strcpy(pty_name, q_ptsname(amaster));
 305     }
 306
 307     return amaster;
 308 }
 309
 310 static void char_pty_open(Chardev *chr,
 311                           ChardevBackend *backend,
 312                           bool *be_opened,
 313                           Error **errp)
 314 {
 315     PtyChardev *s;
 316     int master_fd, slave_fd;
 317     char pty_name[PATH_MAX];
 318     char *name;
 319
 320     master_fd = qemu_openpty_raw(&slave_fd, pty_name);
 321     if (master_fd < 0) {
 322         error_setg_errno(errp, errno, "Failed to create PTY");
 323         return;
 324     }
 325
 326     close(slave_fd);
 327     if (!g_unix_set_fd_nonblocking(master_fd, true, NULL)) {
 328         error_setg_errno(errp, errno, "Failed to set FD nonblocking");
 329         return;
 330     }
 331
 332     chr->filename = g_strdup_printf("pty:%s", pty_name);
 333     qemu_printf("char device redirected to %s (label %s)\n",
 334                 pty_name, chr->label);
 335
 336     s = PTY_CHARDEV(chr);
 337     s->ioc = QIO_CHANNEL(qio_channel_file_new_fd(master_fd));
 338     name = g_strdup_printf("chardev-pty-%s", chr->label);
 339     qio_channel_set_name(QIO_CHANNEL(s->ioc), name);
 340     g_free(name);
 341     s->timer_src = NULL;
 342     *be_opened = false;
 343 }
 344
 345 static void char_pty_class_init(ObjectClass *oc, void *data)
 346 {
 347     ChardevClass *cc = CHARDEV_CLASS(oc);
 348
 349     cc->open = char_pty_open;
 350     cc->chr_write = char_pty_chr_write;
 351     cc->chr_update_read_handler = pty_chr_update_read_handler;
 352     cc->chr_add_watch = pty_chr_add_watch;
 353 }
 354
 355 static const TypeInfo char_pty_type_info = {
 356     .name = TYPE_CHARDEV_PTY,
 357     .parent = TYPE_CHARDEV,
 358     .instance_size = sizeof(PtyChardev),
 359     .instance_finalize = char_pty_finalize,
 360     .class_init = char_pty_class_init,
 361 };
 362
 363 static void register_types(void)
 364 {
 365     type_register_static(&char_pty_type_info);
 366 }
 367
 368 type_init(register_types);