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