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 {
  84     struct sockaddr_in addr;
  85     int ret;
  86
  87     ret = parse_host_port(&addr, host_port);
  88     if (ret < 0) {
  89         return ret;
  90     }
  91
  92     s->get_error = socket_errno;
  93     s->write = socket_write;
  94     s->close = tcp_close;
  95
  96     s->fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
  97     if (s->fd == -1) {
  98         DPRINTF("Unable to open socket");
  99         return -socket_error();
 100     }
 101
 102     socket_set_nonblock(s->fd);
 103
 104     do {
 105         ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr));
 106         if (ret == -1) {
 107             ret = -socket_error();
 108         }
 109         if (ret == -EINPROGRESS || ret == -EWOULDBLOCK) {
 110             qemu_set_fd_handler2(s->fd, NULL, NULL, tcp_wait_for_connect, s);
 111             return 0;
 112         }
 113     } while (ret == -EINTR);
 114
 115     if (ret < 0) {
 116         DPRINTF("connect failed\n");
 117         migrate_fd_error(s);
 118         return ret;
 119     }
 120     migrate_fd_connect(s);
 121     return 0;
 122 }
 123
 124 static void tcp_accept_incoming_migration(void *opaque)
 125 {
 126     struct sockaddr_in addr;
 127     socklen_t addrlen = sizeof(addr);
 128     int s = (intptr_t)opaque;
 129     QEMUFile *f;
 130     int c;
 131
 132     do {
 133         c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen);
 134     } while (c == -1 && socket_error() == EINTR);
 135
 136     DPRINTF("accepted migration\n");
 137
 138     if (c == -1) {
 139         fprintf(stderr, "could not accept migration connection\n");
 140         goto out2;
 141     }
 142
 143     f = qemu_fopen_socket(c);
 144     if (f == NULL) {
 145         fprintf(stderr, "could not qemu_fopen socket\n");
 146         goto out;
 147     }
 148
 149     process_incoming_migration(f);
 150     qemu_fclose(f);
 151 out:
 152     close(c);
 153 out2:
 154     qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
 155     close(s);
 156 }
 157
 158 int tcp_start_incoming_migration(const char *host_port)
 159 {
 160     struct sockaddr_in addr;
 161     int val;
 162     int s;
 163
 164     DPRINTF("Attempting to start an incoming migration\n");
 165
 166     if (parse_host_port(&addr, host_port) < 0) {
 167         fprintf(stderr, "invalid host/port combination: %s\n", host_port);
 168         return -EINVAL;
 169     }
 170
 171     s = qemu_socket(PF_INET, SOCK_STREAM, 0);
 172     if (s == -1) {
 173         return -socket_error();
 174     }
 175
 176     val = 1;
 177     setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&val, sizeof(val));
 178
 179     if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
 180         goto err;
 181     }
 182     if (listen(s, 1) == -1) {
 183         goto err;
 184     }
 185
 186     qemu_set_fd_handler2(s, NULL, tcp_accept_incoming_migration, NULL,
 187                          (void *)(intptr_t)s);
 188
 189     return 0;
 190
 191 err:
 192     close(s);
 193     return -socket_error();
 194 }