char: move pty chardev in its own file

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Eric Blake <eblake@redhat.com>

chardev/Makefile.objs

@@ -6,6 +6,7 @@ chardev-obj-y += char-io.o
 chardev-obj-y += char-mux.o
 chardev-obj-y += char-null.o
 chardev-obj-y += char-pipe.o
+chardev-obj-$(CONFIG_POSIX) += char-pty.o
 chardev-obj-y += char-ringbuf.o
 chardev-obj-y += char-socket.o
 chardev-obj-y += char-stdio.o

chardev/char-pty.c

@@ -0,0 +1,300 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qemu-common.h"
+#include "sysemu/char.h"
+#include "io/channel-file.h"
+#include "qemu/sockets.h"
+#include "qemu/error-report.h"
+
+#include "char-io.h"
+
+#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__)      \
+    || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \
+    || defined(__GLIBC__)
+
+typedef struct {
+    Chardev parent;
+    QIOChannel *ioc;
+    int read_bytes;
+
+    /* Protected by the Chardev chr_write_lock.  */
+    int connected;
+    guint timer_tag;
+    guint open_tag;
+} PtyChardev;
+
+#define PTY_CHARDEV(obj) OBJECT_CHECK(PtyChardev, (obj), TYPE_CHARDEV_PTY)
+
+static void pty_chr_update_read_handler_locked(Chardev *chr);
+static void pty_chr_state(Chardev *chr, int connected);
+
+static gboolean pty_chr_timer(gpointer opaque)
+{
+    struct Chardev *chr = CHARDEV(opaque);
+    PtyChardev *s = PTY_CHARDEV(opaque);
+
+    qemu_mutex_lock(&chr->chr_write_lock);
+    s->timer_tag = 0;
+    s->open_tag = 0;
+    if (!s->connected) {
+        /* Next poll ... */
+        pty_chr_update_read_handler_locked(chr);
+    }
+    qemu_mutex_unlock(&chr->chr_write_lock);
+    return FALSE;
+}
+
+/* Called with chr_write_lock held.  */
+static void pty_chr_rearm_timer(Chardev *chr, int ms)
+{
+    PtyChardev *s = PTY_CHARDEV(chr);
+    char *name;
+
+    if (s->timer_tag) {
+        g_source_remove(s->timer_tag);
+        s->timer_tag = 0;
+    }
+
+    if (ms == 1000) {
+        name = g_strdup_printf("pty-timer-secs-%s", chr->label);
+        s->timer_tag = g_timeout_add_seconds(1, pty_chr_timer, chr);
+    } else {
+        name = g_strdup_printf("pty-timer-ms-%s", chr->label);
+        s->timer_tag = g_timeout_add(ms, pty_chr_timer, chr);
+    }
+    g_source_set_name_by_id(s->timer_tag, name);
+    g_free(name);
+}
+
+/* Called with chr_write_lock held.  */
+static void pty_chr_update_read_handler_locked(Chardev *chr)
+{
+    PtyChardev *s = PTY_CHARDEV(chr);
+    GPollFD pfd;
+    int rc;
+    QIOChannelFile *fioc = QIO_CHANNEL_FILE(s->ioc);
+
+    pfd.fd = fioc->fd;
+    pfd.events = G_IO_OUT;
+    pfd.revents = 0;
+    do {
+        rc = g_poll(&pfd, 1, 0);
+    } while (rc == -1 && errno == EINTR);
+    assert(rc >= 0);
+
+    if (pfd.revents & G_IO_HUP) {
+        pty_chr_state(chr, 0);
+    } else {
+        pty_chr_state(chr, 1);
+    }
+}
+
+static void pty_chr_update_read_handler(Chardev *chr,
+                                        GMainContext *context)
+{
+    qemu_mutex_lock(&chr->chr_write_lock);
+    pty_chr_update_read_handler_locked(chr);
+    qemu_mutex_unlock(&chr->chr_write_lock);
+}
+
+/* Called with chr_write_lock held.  */
+static int char_pty_chr_write(Chardev *chr, const uint8_t *buf, int len)
+{
+    PtyChardev *s = PTY_CHARDEV(chr);
+
+    if (!s->connected) {
+        /* guest sends data, check for (re-)connect */
+        pty_chr_update_read_handler_locked(chr);
+        if (!s->connected) {
+            return 0;
+        }
+    }
+    return io_channel_send(s->ioc, buf, len);
+}
+
+static GSource *pty_chr_add_watch(Chardev *chr, GIOCondition cond)
+{
+    PtyChardev *s = PTY_CHARDEV(chr);
+    if (!s->connected) {
+        return NULL;
+    }
+    return qio_channel_create_watch(s->ioc, cond);
+}
+
+static int pty_chr_read_poll(void *opaque)
+{
+    Chardev *chr = CHARDEV(opaque);
+    PtyChardev *s = PTY_CHARDEV(opaque);
+
+    s->read_bytes = qemu_chr_be_can_write(chr);
+    return s->read_bytes;
+}
+
+static gboolean pty_chr_read(QIOChannel *chan, GIOCondition cond, void *opaque)
+{
+    Chardev *chr = CHARDEV(opaque);
+    PtyChardev *s = PTY_CHARDEV(opaque);
+    gsize len;
+    uint8_t buf[CHR_READ_BUF_LEN];
+    ssize_t ret;
+
+    len = sizeof(buf);
+    if (len > s->read_bytes) {
+        len = s->read_bytes;
+    }
+    if (len == 0) {
+        return TRUE;
+    }
+    ret = qio_channel_read(s->ioc, (char *)buf, len, NULL);
+    if (ret <= 0) {
+        pty_chr_state(chr, 0);
+        return FALSE;
+    } else {
+        pty_chr_state(chr, 1);
+        qemu_chr_be_write(chr, buf, ret);
+    }
+    return TRUE;
+}
+
+static gboolean qemu_chr_be_generic_open_func(gpointer opaque)
+{
+    Chardev *chr = CHARDEV(opaque);
+    PtyChardev *s = PTY_CHARDEV(opaque);
+
+    s->open_tag = 0;
+    qemu_chr_be_generic_open(chr);
+    return FALSE;
+}
+
+/* Called with chr_write_lock held.  */
+static void pty_chr_state(Chardev *chr, int connected)
+{
+    PtyChardev *s = PTY_CHARDEV(chr);
+
+    if (!connected) {
+        if (s->open_tag) {
+            g_source_remove(s->open_tag);
+            s->open_tag = 0;
+        }
+        remove_fd_in_watch(chr);
+        s->connected = 0;
+        /* (re-)connect poll interval for idle guests: once per second.
+         * We check more frequently in case the guests sends data to
+         * the virtual device linked to our pty. */
+        pty_chr_rearm_timer(chr, 1000);
+    } else {
+        if (s->timer_tag) {
+            g_source_remove(s->timer_tag);
+            s->timer_tag = 0;
+        }
+        if (!s->connected) {
+            g_assert(s->open_tag == 0);
+            s->connected = 1;
+            s->open_tag = g_idle_add(qemu_chr_be_generic_open_func, chr);
+        }
+        if (!chr->fd_in_tag) {
+            chr->fd_in_tag = io_add_watch_poll(chr, s->ioc,
+                                               pty_chr_read_poll,
+                                               pty_chr_read,
+                                               chr, NULL);
+        }
+    }
+}
+
+static void char_pty_finalize(Object *obj)
+{
+    Chardev *chr = CHARDEV(obj);
+    PtyChardev *s = PTY_CHARDEV(obj);
+
+    qemu_mutex_lock(&chr->chr_write_lock);
+    pty_chr_state(chr, 0);
+    object_unref(OBJECT(s->ioc));
+    if (s->timer_tag) {
+        g_source_remove(s->timer_tag);
+        s->timer_tag = 0;
+    }
+    qemu_mutex_unlock(&chr->chr_write_lock);
+    qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
+}
+
+static void char_pty_open(Chardev *chr,
+                          ChardevBackend *backend,
+                          bool *be_opened,
+                          Error **errp)
+{
+    PtyChardev *s;
+    int master_fd, slave_fd;
+    char pty_name[PATH_MAX];
+    char *name;
+
+    master_fd = qemu_openpty_raw(&slave_fd, pty_name);
+    if (master_fd < 0) {
+        error_setg_errno(errp, errno, "Failed to create PTY");
+        return;
+    }
+
+    close(slave_fd);
+    qemu_set_nonblock(master_fd);
+
+    chr->filename = g_strdup_printf("pty:%s", pty_name);
+    error_report("char device redirected to %s (label %s)",
+                 pty_name, chr->label);
+
+    s = PTY_CHARDEV(chr);
+    s->ioc = QIO_CHANNEL(qio_channel_file_new_fd(master_fd));
+    name = g_strdup_printf("chardev-pty-%s", chr->label);
+    qio_channel_set_name(QIO_CHANNEL(s->ioc), name);
+    g_free(name);
+    s->timer_tag = 0;
+    *be_opened = false;
+}
+
+static void char_pty_class_init(ObjectClass *oc, void *data)
+{
+    ChardevClass *cc = CHARDEV_CLASS(oc);
+
+    cc->open = char_pty_open;
+    cc->chr_write = char_pty_chr_write;
+    cc->chr_update_read_handler = pty_chr_update_read_handler;
+    cc->chr_add_watch = pty_chr_add_watch;
+}
+
+static const TypeInfo char_pty_type_info = {
+    .name = TYPE_CHARDEV_PTY,
+    .parent = TYPE_CHARDEV,
+    .instance_size = sizeof(PtyChardev),
+    .instance_finalize = char_pty_finalize,
+    .class_init = char_pty_class_init,
+};
+
+static void register_types(void)
+{
+    type_register_static(&char_pty_type_info);
+}
+
+type_init(register_types);
+
+#endif