LXR qemu/migration/fd.c

   1/*
   2 * QEMU live migration via generic fd
   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#include "qapi/error.h"
  18#include "qemu-common.h"
  19#include "qemu/main-loop.h"
  20#include "qemu/sockets.h"
  21#include "migration/migration.h"
  22#include "monitor/monitor.h"
  23#include "migration/qemu-file.h"
  24#include "block/block.h"
  25
  26//#define DEBUG_MIGRATION_FD
  27
  28#ifdef DEBUG_MIGRATION_FD
  29#define DPRINTF(fmt, ...) \
  30    do { printf("migration-fd: " fmt, ## __VA_ARGS__); } while (0)
  31#else
  32#define DPRINTF(fmt, ...) \
  33    do { } while (0)
  34#endif
  35
  36static bool fd_is_socket(int fd)
  37{
  38    struct stat stat;
  39    int ret = fstat(fd, &stat);
  40    if (ret == -1) {
  41        /* When in doubt say no */
  42        return false;
  43    }
  44    return S_ISSOCK(stat.st_mode);
  45}
  46
  47void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error **errp)
  48{
  49    int fd = monitor_get_fd(cur_mon, fdname, errp);
  50    if (fd == -1) {
  51        return;
  52    }
  53
  54    if (fd_is_socket(fd)) {
  55        s->to_dst_file = qemu_fopen_socket(fd, "wb");
  56    } else {
  57        s->to_dst_file = qemu_fdopen(fd, "wb");
  58    }
  59
  60    migrate_fd_connect(s);
  61}
  62
  63static void fd_accept_incoming_migration(void *opaque)
  64{
  65    QEMUFile *f = opaque;
  66
  67    qemu_set_fd_handler(qemu_get_fd(f), NULL, NULL, NULL);
  68    process_incoming_migration(f);
  69}
  70
  71void fd_start_incoming_migration(const char *infd, Error **errp)
  72{
  73    int fd;
  74    QEMUFile *f;
  75
  76    DPRINTF("Attempting to start an incoming migration via fd\n");
  77
  78    fd = strtol(infd, NULL, 0);
  79    if (fd_is_socket(fd)) {
  80        f = qemu_fopen_socket(fd, "rb");
  81    } else {
  82        f = qemu_fdopen(fd, "rb");
  83    }
  84    if(f == NULL) {
  85        error_setg_errno(errp, errno, "failed to open the source descriptor");
  86        return;
  87    }
  88
  89    qemu_set_fd_handler(fd, fd_accept_incoming_migration, NULL, f);
  90}
  91