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/*

 * QEMU live migration via Unix Domain Sockets

 *

 * Copyright Red Hat, Inc. 2009

 *

 * Authors:

 *  Chris Lalancette <clalance@redhat.com>

 *

 * This work is licensed under the terms of the GNU GPL, version 2.  See

 * the COPYING file in the top-level directory.

 *

 * Contributions after 2012-01-13 are licensed under the terms of the

 * GNU GPL, version 2 or (at your option) any later version.

 */

#include "qemu-common.h"

#include "qemu_socket.h"

#include "migration.h"

#include "qemu-char.h"

#include "buffered_file.h"

#include "block.h"

//#define DEBUG_MIGRATION_UNIX

#ifdef DEBUG_MIGRATION_UNIX

#define DPRINTF(fmt, ...) \

    do { printf("migration-unix: " fmt, ## __VA_ARGS__); } while (0)

#else

#define DPRINTF(fmt, ...) \

    do { } while (0)

#endif

static int unix_errno(MigrationState *s)

{

    return errno;

}

static int unix_write(MigrationState *s, const void * buf, size_t size)

{

    return write(s->fd, buf, size);

}

static int unix_close(MigrationState *s)

{

    int r = 0;

    DPRINTF("unix_close\n");

    if (close(s->fd) < 0) {

        r = -errno;

    }

    return r;

}

static void unix_wait_for_connect(int fd, void *opaque)

{

    MigrationState *s = opaque;

    if (fd < 0) {

        DPRINTF("migrate connect error\n");

        s->fd = -1;

        migrate_fd_error(s);

    } else {

        DPRINTF("migrate connect success\n");

        s->fd = fd;

        migrate_fd_connect(s);

    }

}

void unix_start_outgoing_migration(MigrationState *s, const char *path, Error **errp)

{

    s->get_error = unix_errno;

    s->write = unix_write;

    s->close = unix_close;

    s->fd = unix_nonblocking_connect(path, unix_wait_for_connect, s, errp);

}

static void unix_accept_incoming_migration(void *opaque)

{

    struct sockaddr_un addr;

    socklen_t addrlen = sizeof(addr);

    int s = (intptr_t)opaque;

    QEMUFile *f;

    int c;

    do {

        c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen);

    } while (c == -1 && errno == EINTR);

    qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);

    close(s);

    DPRINTF("accepted migration\n");

    if (c == -1) {

        fprintf(stderr, "could not accept migration connection\n");

        goto out;

    }

    f = qemu_fopen_socket(c);

    if (f == NULL) {

        fprintf(stderr, "could not qemu_fopen socket\n");

        goto out;

    }

    process_incoming_migration(f);

    return;

out:

    close(c);

}

void unix_start_incoming_migration(const char *path, Error **errp)

{

    int s;

    s = unix_listen(path, NULL, 0, errp);

    if (s < 0) {

        return;

    }

    qemu_set_fd_handler2(s, NULL, unix_accept_incoming_migration, NULL,

                         (void *)(intptr_t)s);

}