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(MigrationState *s)
  32 {
  33     return socket_error();
  34 }
  35
  36 static int socket_write(MigrationState *s, const void * buf, size_t size)
  37 {
  38     return send(s->fd, buf, size, 0);
  39 }
  40
  41 static int tcp_close(MigrationState *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     MigrationState *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 && (socket_error()) == 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 int tcp_start_outgoing_migration(MigrationState *s, const char *host_port)
  79 {
  80     struct sockaddr_in addr;
  81     int ret;
  82
  83     ret = parse_host_port(&addr, host_port);
  84     if (ret < 0) {
  85         return ret;
  86     }
  87     s->get_error = socket_errno;
  88     s->write = socket_write;
  89     s->close = tcp_close;
  90
  91     s->fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
  92     if (s->fd == -1) {
  93         return -1;
  94     }
  95
  96     socket_set_nonblock(s->fd);
  97
  98     do {
  99         ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr));
 100         if (ret == -1)
 101             ret = -(socket_error());
 102
 103         if (ret == -EINPROGRESS || ret == -EWOULDBLOCK)
 104             qemu_set_fd_handler2(s->fd, NULL, NULL, tcp_wait_for_connect, s);
 105     } while (ret == -EINTR);
 106
 107     if (ret < 0 && ret != -EINPROGRESS && ret != -EWOULDBLOCK) {
 108         DPRINTF("connect failed\n");
 109         migrate_fd_error(s);
 110     } else if (ret >= 0)
 111         migrate_fd_connect(s);
 112
 113     return 0;
 114 }
 115
 116 static void tcp_accept_incoming_migration(void *opaque)
 117 {
 118     struct sockaddr_in addr;
 119     socklen_t addrlen = sizeof(addr);
 120     int s = (intptr_t)opaque;
 121     QEMUFile *f;
 122     int c;
 123
 124     do {
 125         c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen);
 126     } while (c == -1 && socket_error() == EINTR);
 127
 128     DPRINTF("accepted migration\n");
 129
 130     if (c == -1) {
 131         fprintf(stderr, "could not accept migration connection\n");
 132         goto out2;
 133     }
 134
 135     f = qemu_fopen_socket(c);
 136     if (f == NULL) {
 137         fprintf(stderr, "could not qemu_fopen socket\n");
 138         goto out;
 139     }
 140
 141     process_incoming_migration(f);
 142     qemu_fclose(f);
 143 out:
 144     close(c);
 145 out2:
 146     qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
 147     close(s);
 148 }
 149
 150 int tcp_start_incoming_migration(const char *host_port)
 151 {
 152     struct sockaddr_in addr;
 153     int val;
 154     int s;
 155
 156     if (parse_host_port(&addr, host_port) < 0) {
 157         fprintf(stderr, "invalid host/port combination: %s\n", host_port);
 158         return -EINVAL;
 159     }
 160
 161     s = qemu_socket(PF_INET, SOCK_STREAM, 0);
 162     if (s == -1)
 163         return -socket_error();
 164
 165     val = 1;
 166     setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&val, sizeof(val));
 167
 168     if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1)
 169         goto err;
 170
 171     if (listen(s, 1) == -1)
 172         goto err;
 173
 174     qemu_set_fd_handler2(s, NULL, tcp_accept_incoming_migration, NULL,
 175                          (void *)(intptr_t)s);
 176
 177     return 0;
 178
 179 err:
 180     close(s);
 181     return -socket_error();
 182 }