migration-tcp.c

   1 /*
   2  * QEMU live migration
   3  *
   4  * Copyright IBM, Corp. 2008
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.ibm.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  */
  13
  14 #include "qemu-common.h"
  15 #include "qemu_socket.h"
  16 #include "migration.h"
  17 #include "qemu-char.h"
  18 #include "sysemu.h"
  19 #include "buffered_file.h"
  20 #include "block.h"
  21
  22 //#define DEBUG_MIGRATION_TCP
  23
  24 #ifdef DEBUG_MIGRATION_TCP
  25 #define dprintf(fmt, ...) \
  26     do { printf("migration-tcp: " fmt, ## __VA_ARGS__); } while (0)
  27 #else
  28 #define dprintf(fmt, ...) \
  29     do { } while (0)
  30 #endif
  31
  32 static int socket_errno(FdMigrationState *s)
  33 {
  34     return socket_error();
  35 }
  36
  37 static int socket_write(FdMigrationState *s, const void * buf, size_t size)
  38 {
  39     return send(s->fd, buf, size, 0);
  40 }
  41
  42 static int tcp_close(FdMigrationState *s)
  43 {
  44     dprintf("tcp_close\n");
  45     if (s->fd != -1) {
  46         close(s->fd);
  47         s->fd = -1;
  48     }
  49     return 0;
  50 }
  51
  52
  53 static void tcp_wait_for_connect(void *opaque)
  54 {
  55     FdMigrationState *s = opaque;
  56     int val, ret;
  57     socklen_t valsize = sizeof(val);
  58
  59     dprintf("connect completed\n");
  60     do {
  61         ret = getsockopt(s->fd, SOL_SOCKET, SO_ERROR, (void *) &val, &valsize);
  62     } while (ret == -1 && (s->get_error(s)) == EINTR);
  63
  64     if (ret < 0) {
  65         migrate_fd_error(s);
  66         return;
  67     }
  68
  69     qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
  70
  71     if (val == 0)
  72         migrate_fd_connect(s);
  73     else {
  74         dprintf("error connecting %d\n", val);
  75         migrate_fd_error(s);
  76     }
  77 }
  78
  79 MigrationState *tcp_start_outgoing_migration(const char *host_port,
  80                                              int64_t bandwidth_limit,
  81                                              int detach)
  82 {
  83     struct sockaddr_in addr;
  84     FdMigrationState *s;
  85     int ret;
  86
  87     if (parse_host_port(&addr, host_port) < 0)
  88         return NULL;
  89
  90     s = qemu_mallocz(sizeof(*s));
  91
  92     s->get_error = socket_errno;
  93     s->write = socket_write;
  94     s->close = tcp_close;
  95     s->mig_state.cancel = migrate_fd_cancel;
  96     s->mig_state.get_status = migrate_fd_get_status;
  97     s->mig_state.release = migrate_fd_release;
  98
  99     s->state = MIG_STATE_ACTIVE;
 100     s->mon_resume = NULL;
 101     s->bandwidth_limit = bandwidth_limit;
 102     s->fd = socket(PF_INET, SOCK_STREAM, 0);
 103     if (s->fd == -1) {
 104         qemu_free(s);
 105         return NULL;
 106     }
 107
 108     socket_set_nonblock(s->fd);
 109
 110     if (!detach)
 111         migrate_fd_monitor_suspend(s);
 112
 113     do {
 114         ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr));
 115         if (ret == -1)
 116             ret = -(s->get_error(s));
 117
 118         if (ret == -EINPROGRESS || ret == -EWOULDBLOCK)
 119             qemu_set_fd_handler2(s->fd, NULL, NULL, tcp_wait_for_connect, s);
 120     } while (ret == -EINTR);
 121
 122     if (ret < 0 && ret != -EINPROGRESS && ret != -EWOULDBLOCK) {
 123         dprintf("connect failed\n");
 124         close(s->fd);
 125         qemu_free(s);
 126         return NULL;
 127     } else if (ret >= 0)
 128         migrate_fd_connect(s);
 129
 130     return &s->mig_state;
 131 }
 132
 133 static void tcp_accept_incoming_migration(void *opaque)
 134 {
 135     struct sockaddr_in addr;
 136     socklen_t addrlen = sizeof(addr);
 137     int s = (unsigned long)opaque;
 138     QEMUFile *f;
 139     int c, ret;
 140
 141     do {
 142         c = accept(s, (struct sockaddr *)&addr, &addrlen);
 143     } while (c == -1 && socket_error() == EINTR);
 144
 145     dprintf("accepted migration\n");
 146
 147     if (c == -1) {
 148         fprintf(stderr, "could not accept migration connection\n");
 149         return;
 150     }
 151
 152     f = qemu_fopen_socket(c);
 153     if (f == NULL) {
 154         fprintf(stderr, "could not qemu_fopen socket\n");
 155         goto out;
 156     }
 157
 158     ret = qemu_loadvm_state(f);
 159     if (ret < 0) {
 160         fprintf(stderr, "load of migration failed\n");
 161         goto out_fopen;
 162     }
 163     qemu_announce_self();
 164     dprintf("successfully loaded vm state\n");
 165
 166     /* we've successfully migrated, close the server socket */
 167     qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
 168     close(s);
 169
 170 out_fopen:
 171     qemu_fclose(f);
 172 out:
 173     close(c);
 174 }
 175
 176 int tcp_start_incoming_migration(const char *host_port)
 177 {
 178     struct sockaddr_in addr;
 179     int val;
 180     int s;
 181
 182     if (parse_host_port(&addr, host_port) < 0) {
 183         fprintf(stderr, "invalid host/port combination: %s\n", host_port);
 184         return -EINVAL;
 185     }
 186
 187     s = socket(PF_INET, SOCK_STREAM, 0);
 188     if (s == -1)
 189         return -socket_error();
 190
 191     val = 1;
 192     setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&val, sizeof(val));
 193
 194     if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1)
 195         goto err;
 196
 197     if (listen(s, 1) == -1)
 198         goto err;
 199
 200     qemu_set_fd_handler2(s, NULL, tcp_accept_incoming_migration, NULL,
 201                          (void *)(unsigned long)s);
 202
 203     return 0;
 204
 205 err:
 206     close(s);
 207     return -socket_error();
 208 }