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  * 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_socket.h"
  18 #include "migration.h"
  19 #include "qemu-char.h"
  20 #include "buffered_file.h"
  21 #include "block.h"
  22
  23 //#define DEBUG_MIGRATION_TCP
  24
  25 #ifdef DEBUG_MIGRATION_TCP
  26 #define DPRINTF(fmt, ...) \
  27     do { printf("migration-tcp: " fmt, ## __VA_ARGS__); } while (0)
  28 #else
  29 #define DPRINTF(fmt, ...) \
  30     do { } while (0)
  31 #endif
  32
  33 static int socket_errno(MigrationState *s)
  34 {
  35     return socket_error();
  36 }
  37
  38 static int socket_write(MigrationState *s, const void * buf, size_t size)
  39 {
  40     return send(s->fd, buf, size, 0);
  41 }
  42
  43 static int tcp_close(MigrationState *s)
  44 {
  45     int r = 0;
  46     DPRINTF("tcp_close\n");
  47     if (s->fd != -1) {
  48         if (close(s->fd) < 0) {
  49             r = -errno;
  50         }
  51         s->fd = -1;
  52     }
  53     return r;
  54 }
  55
  56 static void tcp_wait_for_connect(void *opaque)
  57 {
  58     MigrationState *s = opaque;
  59     int val, ret;
  60     socklen_t valsize = sizeof(val);
  61
  62     DPRINTF("connect completed\n");
  63     do {
  64         ret = getsockopt(s->fd, SOL_SOCKET, SO_ERROR, (void *) &val, &valsize);
  65     } while (ret == -1 && (socket_error()) == EINTR);
  66
  67     if (ret < 0) {
  68         migrate_fd_error(s);
  69         return;
  70     }
  71
  72     qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
  73
  74     if (val == 0)
  75         migrate_fd_connect(s);
  76     else {
  77         DPRINTF("error connecting %d\n", val);
  78         migrate_fd_error(s);
  79     }
  80 }
  81
  82 int tcp_start_outgoing_migration(MigrationState *s, const char *host_port,
  83                                  Error **errp)
  84 {
  85     s->get_error = socket_errno;
  86     s->write = socket_write;
  87     s->close = tcp_close;
  88
  89     s->fd = inet_connect(host_port, false, errp);
  90
  91     if (!error_is_set(errp)) {
  92         migrate_fd_connect(s);
  93     } else if (error_is_type(*errp, QERR_SOCKET_CONNECT_IN_PROGRESS)) {
  94         DPRINTF("connect in progress\n");
  95         qemu_set_fd_handler2(s->fd, NULL, NULL, tcp_wait_for_connect, s);
  96     } else if (error_is_type(*errp, QERR_SOCKET_CREATE_FAILED)) {
  97         DPRINTF("connect failed\n");
  98         return -1;
  99     } else if (error_is_type(*errp, QERR_SOCKET_CONNECT_FAILED)) {
 100         DPRINTF("connect failed\n");
 101         migrate_fd_error(s);
 102         return -1;
 103     } else {
 104         DPRINTF("unknown error\n");
 105         return -1;
 106     }
 107
 108     return 0;
 109 }
 110
 111 static void tcp_accept_incoming_migration(void *opaque)
 112 {
 113     struct sockaddr_in addr;
 114     socklen_t addrlen = sizeof(addr);
 115     int s = (intptr_t)opaque;
 116     QEMUFile *f;
 117     int c;
 118
 119     do {
 120         c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen);
 121     } while (c == -1 && socket_error() == EINTR);
 122
 123     DPRINTF("accepted migration\n");
 124
 125     if (c == -1) {
 126         fprintf(stderr, "could not accept migration connection\n");
 127         goto out2;
 128     }
 129
 130     f = qemu_fopen_socket(c);
 131     if (f == NULL) {
 132         fprintf(stderr, "could not qemu_fopen socket\n");
 133         goto out;
 134     }
 135
 136     process_incoming_migration(f);
 137     qemu_fclose(f);
 138 out:
 139     close(c);
 140 out2:
 141     qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
 142     close(s);
 143 }
 144
 145 int tcp_start_incoming_migration(const char *host_port, Error **errp)
 146 {
 147     int s;
 148
 149     s = inet_listen(host_port, NULL, 256, SOCK_STREAM, 0, errp);
 150
 151     if (s < 0) {
 152         return -1;
 153     }
 154
 155     qemu_set_fd_handler2(s, NULL, tcp_accept_incoming_migration, NULL,
 156                          (void *)(intptr_t)s);
 157
 158     return 0;
 159 }