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 "buffered_file.h"
  19 #include "block.h"
  20
  21 //#define DEBUG_MIGRATION_TCP
  22
  23 #ifdef DEBUG_MIGRATION_TCP
  24 #define DPRINTF(fmt, ...) \
  25     do { printf("migration-tcp: " fmt, ## __VA_ARGS__); } while (0)
  26 #else
  27 #define DPRINTF(fmt, ...) \
  28     do { } while (0)
  29 #endif
  30
  31 static int socket_errno(FdMigrationState *s)
  32 {
  33     return socket_error();
  34 }
  35
  36 static int socket_write(FdMigrationState *s, const void * buf, size_t size)
  37 {
  38     return send(s->fd, buf, size, 0);
  39 }
  40
  41 static int tcp_close(FdMigrationState *s)
  42 {
  43     DPRINTF("tcp_close\n");
  44     if (s->fd != -1) {
  45         close(s->fd);
  46         s->fd = -1;
  47     }
  48     return 0;
  49 }
  50
  51
  52 static void tcp_wait_for_connect(void *opaque)
  53 {
  54     FdMigrationState *s = opaque;
  55     int val, ret;
  56     socklen_t valsize = sizeof(val);
  57
  58     DPRINTF("connect completed\n");
  59     do {
  60         ret = getsockopt(s->fd, SOL_SOCKET, SO_ERROR, (void *) &val, &valsize);
  61     } while (ret == -1 && (s->get_error(s)) == EINTR);
  62
  63     if (ret < 0) {
  64         migrate_fd_error(s);
  65         return;
  66     }
  67
  68     qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
  69
  70     if (val == 0)
  71         migrate_fd_connect(s);
  72     else {
  73         DPRINTF("error connecting %d\n", val);
  74         migrate_fd_error(s);
  75     }
  76 }
  77
  78 MigrationState *tcp_start_outgoing_migration(Monitor *mon,
  79                                              const char *host_port,
  80                                              int64_t bandwidth_limit,
  81                                              int detach,
  82                                              int blk,
  83                                              int inc)
  84 {
  85     struct sockaddr_in addr;
  86     FdMigrationState *s;
  87     int ret;
  88
  89     if (parse_host_port(&addr, host_port) < 0)
  90         return NULL;
  91
  92     s = qemu_mallocz(sizeof(*s));
  93
  94     s->get_error = socket_errno;
  95     s->write = socket_write;
  96     s->close = tcp_close;
  97     s->mig_state.cancel = migrate_fd_cancel;
  98     s->mig_state.get_status = migrate_fd_get_status;
  99     s->mig_state.release = migrate_fd_release;
 100
 101     s->mig_state.blk = blk;
 102     s->mig_state.shared = inc;
 103
 104     s->state = MIG_STATE_ACTIVE;
 105     s->mon = NULL;
 106     s->bandwidth_limit = bandwidth_limit;
 107     s->fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
 108     if (s->fd == -1) {
 109         qemu_free(s);
 110         return NULL;
 111     }
 112
 113     socket_set_nonblock(s->fd);
 114
 115     if (!detach) {
 116         migrate_fd_monitor_suspend(s, mon);
 117     }
 118
 119     do {
 120         ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr));
 121         if (ret == -1)
 122             ret = -(s->get_error(s));
 123
 124         if (ret == -EINPROGRESS || ret == -EWOULDBLOCK)
 125             qemu_set_fd_handler2(s->fd, NULL, NULL, tcp_wait_for_connect, s);
 126     } while (ret == -EINTR);
 127
 128     if (ret < 0 && ret != -EINPROGRESS && ret != -EWOULDBLOCK) {
 129         DPRINTF("connect failed\n");
 130         migrate_fd_error(s);
 131     } else if (ret >= 0)
 132         migrate_fd_connect(s);
 133
 134     return &s->mig_state;
 135 }
 136
 137 static void tcp_accept_incoming_migration(void *opaque)
 138 {
 139     struct sockaddr_in addr;
 140     socklen_t addrlen = sizeof(addr);
 141     int s = (intptr_t)opaque;
 142     QEMUFile *f;
 143     int c;
 144
 145     do {
 146         c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen);
 147     } while (c == -1 && socket_error() == EINTR);
 148
 149     DPRINTF("accepted migration\n");
 150
 151     if (c == -1) {
 152         fprintf(stderr, "could not accept migration connection\n");
 153         goto out2;
 154     }
 155
 156     f = qemu_fopen_socket(c);
 157     if (f == NULL) {
 158         fprintf(stderr, "could not qemu_fopen socket\n");
 159         goto out;
 160     }
 161
 162     process_incoming_migration(f);
 163     qemu_fclose(f);
 164 out:
 165     close(c);
 166 out2:
 167     qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
 168     close(s);
 169 }
 170
 171 int tcp_start_incoming_migration(const char *host_port)
 172 {
 173     struct sockaddr_in addr;
 174     int val;
 175     int s;
 176
 177     if (parse_host_port(&addr, host_port) < 0) {
 178         fprintf(stderr, "invalid host/port combination: %s\n", host_port);
 179         return -EINVAL;
 180     }
 181
 182     s = qemu_socket(PF_INET, SOCK_STREAM, 0);
 183     if (s == -1)
 184         return -socket_error();
 185
 186     val = 1;
 187     setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&val, sizeof(val));
 188
 189     if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1)
 190         goto err;
 191
 192     if (listen(s, 1) == -1)
 193         goto err;
 194
 195     qemu_set_fd_handler2(s, NULL, tcp_accept_incoming_migration, NULL,
 196                          (void *)(intptr_t)s);
 197
 198     return 0;
 199
 200 err:
 201     close(s);
 202     return -socket_error();
 203 }