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     bool in_progress;
  86
  87     s->get_error = socket_errno;
  88     s->write = socket_write;
  89     s->close = tcp_close;
  90
  91     s->fd = inet_connect(host_port, false, &in_progress, errp);
  92     if (error_is_set(errp)) {
  93         migrate_fd_error(s);
  94         return -1;
  95     }
  96
  97     if (in_progress) {
  98         DPRINTF("connect in progress\n");
  99         qemu_set_fd_handler2(s->fd, NULL, NULL, tcp_wait_for_connect, s);
 100     } else {
 101         migrate_fd_connect(s);
 102     }
 103
 104     return 0;
 105 }
 106
 107 static void tcp_accept_incoming_migration(void *opaque)
 108 {
 109     struct sockaddr_in addr;
 110     socklen_t addrlen = sizeof(addr);
 111     int s = (intptr_t)opaque;
 112     QEMUFile *f;
 113     int c;
 114
 115     do {
 116         c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen);
 117     } while (c == -1 && socket_error() == EINTR);
 118
 119     DPRINTF("accepted migration\n");
 120
 121     if (c == -1) {
 122         fprintf(stderr, "could not accept migration connection\n");
 123         goto out2;
 124     }
 125
 126     f = qemu_fopen_socket(c);
 127     if (f == NULL) {
 128         fprintf(stderr, "could not qemu_fopen socket\n");
 129         goto out;
 130     }
 131
 132     process_incoming_migration(f);
 133     qemu_fclose(f);
 134 out:
 135     close(c);
 136 out2:
 137     qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
 138     close(s);
 139 }
 140
 141 int tcp_start_incoming_migration(const char *host_port, Error **errp)
 142 {
 143     int s;
 144
 145     s = inet_listen(host_port, NULL, 256, SOCK_STREAM, 0, errp);
 146
 147     if (s < 0) {
 148         return -1;
 149     }
 150
 151     qemu_set_fd_handler2(s, NULL, tcp_accept_incoming_migration, NULL,
 152                          (void *)(intptr_t)s);
 153
 154     return 0;
 155 }