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 static void tcp_wait_for_connect(void *opaque)
  52 {
  53     MigrationState *s = opaque;
  54     int val, ret;
  55     socklen_t valsize = sizeof(val);
  56
  57     DPRINTF("connect completed\n");
  58     do {
  59         ret = getsockopt(s->fd, SOL_SOCKET, SO_ERROR, (void *) &val, &valsize);
  60     } while (ret == -1 && (socket_error()) == EINTR);
  61
  62     if (ret < 0) {
  63         migrate_fd_error(s);
  64         return;
  65     }
  66
  67     qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
  68
  69     if (val == 0)
  70         migrate_fd_connect(s);
  71     else {
  72         DPRINTF("error connecting %d\n", val);
  73         migrate_fd_error(s);
  74     }
  75 }
  76
  77 int tcp_start_outgoing_migration(MigrationState *s, const char *host_port)
  78 {
  79     struct sockaddr_in addr;
  80     int ret;
  81
  82     ret = parse_host_port(&addr, host_port);
  83     if (ret < 0) {
  84         return ret;
  85     }
  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         DPRINTF("Unable to open socket");
  94         return -socket_error();
  95     }
  96
  97     socket_set_nonblock(s->fd);
  98
  99     do {
 100         ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr));
 101         if (ret == -1) {
 102             ret = -socket_error();
 103         }
 104         if (ret == -EINPROGRESS || ret == -EWOULDBLOCK) {
 105             qemu_set_fd_handler2(s->fd, NULL, NULL, tcp_wait_for_connect, s);
 106             return 0;
 107         }
 108     } while (ret == -EINTR);
 109
 110     if (ret < 0) {
 111         DPRINTF("connect failed\n");
 112         migrate_fd_error(s);
 113         return ret;
 114     }
 115     migrate_fd_connect(s);
 116     return 0;
 117 }
 118
 119 static void tcp_accept_incoming_migration(void *opaque)
 120 {
 121     struct sockaddr_in addr;
 122     socklen_t addrlen = sizeof(addr);
 123     int s = (intptr_t)opaque;
 124     QEMUFile *f;
 125     int c;
 126
 127     do {
 128         c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen);
 129     } while (c == -1 && socket_error() == EINTR);
 130
 131     DPRINTF("accepted migration\n");
 132
 133     if (c == -1) {
 134         fprintf(stderr, "could not accept migration connection\n");
 135         goto out2;
 136     }
 137
 138     f = qemu_fopen_socket(c);
 139     if (f == NULL) {
 140         fprintf(stderr, "could not qemu_fopen socket\n");
 141         goto out;
 142     }
 143
 144     process_incoming_migration(f);
 145     qemu_fclose(f);
 146 out:
 147     close(c);
 148 out2:
 149     qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
 150     close(s);
 151 }
 152
 153 int tcp_start_incoming_migration(const char *host_port)
 154 {
 155     struct sockaddr_in addr;
 156     int val;
 157     int s;
 158
 159     DPRINTF("Attempting to start an incoming migration\n");
 160
 161     if (parse_host_port(&addr, host_port) < 0) {
 162         fprintf(stderr, "invalid host/port combination: %s\n", host_port);
 163         return -EINVAL;
 164     }
 165
 166     s = qemu_socket(PF_INET, SOCK_STREAM, 0);
 167     if (s == -1) {
 168         return -socket_error();
 169     }
 170
 171     val = 1;
 172     setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&val, sizeof(val));
 173
 174     if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
 175         goto err;
 176     }
 177     if (listen(s, 1) == -1) {
 178         goto err;
 179     }
 180
 181     qemu_set_fd_handler2(s, NULL, tcp_accept_incoming_migration, NULL,
 182                          (void *)(intptr_t)s);
 183
 184     return 0;
 185
 186 err:
 187     close(s);
 188     return -socket_error();
 189 }