LXR qemu/migration/unix.c

   1/*
   2 * QEMU live migration via Unix Domain Sockets
   3 *
   4 * Copyright Red Hat, Inc. 2009
   5 *
   6 * Authors:
   7 *  Chris Lalancette <clalance@redhat.com>
   8 *
   9 * This work is licensed under the terms of the GNU GPL, version 2.  See
  10 * the COPYING file in the top-level directory.
  11 *
  12 * Contributions after 2012-01-13 are licensed under the terms of the
  13 * GNU GPL, version 2 or (at your option) any later version.
  14 */
  15
  16#include "qemu/osdep.h"
  17
  18#include "qemu-common.h"
  19#include "qemu/error-report.h"
  20#include "qemu/sockets.h"
  21#include "qemu/main-loop.h"
  22#include "migration/migration.h"
  23#include "migration/qemu-file.h"
  24#include "block/block.h"
  25
  26//#define DEBUG_MIGRATION_UNIX
  27
  28#ifdef DEBUG_MIGRATION_UNIX
  29#define DPRINTF(fmt, ...) \
  30    do { printf("migration-unix: " fmt, ## __VA_ARGS__); } while (0)
  31#else
  32#define DPRINTF(fmt, ...) \
  33    do { } while (0)
  34#endif
  35
  36static void unix_wait_for_connect(int fd, Error *err, void *opaque)
  37{
  38    MigrationState *s = opaque;
  39
  40    if (fd < 0) {
  41        DPRINTF("migrate connect error: %s\n", error_get_pretty(err));
  42        s->to_dst_file = NULL;
  43        migrate_fd_error(s);
  44    } else {
  45        DPRINTF("migrate connect success\n");
  46        s->to_dst_file = qemu_fopen_socket(fd, "wb");
  47        migrate_fd_connect(s);
  48    }
  49}
  50
  51void unix_start_outgoing_migration(MigrationState *s, const char *path, Error **errp)
  52{
  53    unix_nonblocking_connect(path, unix_wait_for_connect, s, errp);
  54}
  55
  56static void unix_accept_incoming_migration(void *opaque)
  57{
  58    struct sockaddr_un addr;
  59    socklen_t addrlen = sizeof(addr);
  60    int s = (intptr_t)opaque;
  61    QEMUFile *f;
  62    int c, err;
  63
  64    do {
  65        c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen);
  66        err = errno;
  67    } while (c < 0 && err == EINTR);
  68    qemu_set_fd_handler(s, NULL, NULL, NULL);
  69    close(s);
  70
  71    DPRINTF("accepted migration\n");
  72
  73    if (c < 0) {
  74        error_report("could not accept migration connection (%s)",
  75                     strerror(err));
  76        return;
  77    }
  78
  79    f = qemu_fopen_socket(c, "rb");
  80    if (f == NULL) {
  81        error_report("could not qemu_fopen socket");
  82        goto out;
  83    }
  84
  85    process_incoming_migration(f);
  86    return;
  87
  88out:
  89    close(c);
  90}
  91
  92void unix_start_incoming_migration(const char *path, Error **errp)
  93{
  94    int s;
  95
  96    s = unix_listen(path, NULL, 0, errp);
  97    if (s < 0) {
  98        return;
  99    }
 100
 101    qemu_set_fd_handler(s, unix_accept_incoming_migration, NULL,
 102                        (void *)(intptr_t)s);
 103}
 104