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