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     int r = 0;
  44     DPRINTF("tcp_close\n");
  45     if (s->fd != -1) {
  46         if (close(s->fd) < 0) {
  47             r = -errno;
  48         }
  49         s->fd = -1;
  50     }
  51     return r;
  52 }
  53
  54 static void tcp_wait_for_connect(void *opaque)
  55 {
  56     MigrationState *s = opaque;
  57     int val, ret;
  58     socklen_t valsize = sizeof(val);
  59
  60     DPRINTF("connect completed\n");
  61     do {
  62         ret = getsockopt(s->fd, SOL_SOCKET, SO_ERROR, (void *) &val, &valsize);
  63     } while (ret == -1 && (socket_error()) == EINTR);
  64
  65     if (ret < 0) {
  66         migrate_fd_error(s);
  67         return;
  68     }
  69
  70     qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
  71
  72     if (val == 0)
  73         migrate_fd_connect(s);
  74     else {
  75         DPRINTF("error connecting %d\n", val);
  76         migrate_fd_error(s);
  77     }
  78 }
  79
  80 int tcp_start_outgoing_migration(MigrationState *s, const char *host_port)
  81 {
  82     struct sockaddr_in addr;
  83     int ret;
  84
  85     ret = parse_host_port(&addr, host_port);
  86     if (ret < 0) {
  87         return ret;
  88     }
  89
  90     s->get_error = socket_errno;
  91     s->write = socket_write;
  92     s->close = tcp_close;
  93
  94     s->fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
  95     if (s->fd == -1) {
  96         DPRINTF("Unable to open socket");
  97         return -socket_error();
  98     }
  99
 100     socket_set_nonblock(s->fd);
 101
 102     do {
 103         ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr));
 104         if (ret == -1) {
 105             ret = -socket_error();
 106         }
 107         if (ret == -EINPROGRESS || ret == -EWOULDBLOCK) {
 108             qemu_set_fd_handler2(s->fd, NULL, NULL, tcp_wait_for_connect, s);
 109             return 0;
 110         }
 111     } while (ret == -EINTR);
 112
 113     if (ret < 0) {
 114         DPRINTF("connect failed\n");
 115         migrate_fd_error(s);
 116         return ret;
 117     }
 118     migrate_fd_connect(s);
 119     return 0;
 120 }
 121
 122 static void tcp_accept_incoming_migration(void *opaque)
 123 {
 124     struct sockaddr_in addr;
 125     socklen_t addrlen = sizeof(addr);
 126     int s = (intptr_t)opaque;
 127     QEMUFile *f;
 128     int c;
 129
 130     do {
 131         c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen);
 132     } while (c == -1 && socket_error() == EINTR);
 133
 134     DPRINTF("accepted migration\n");
 135
 136     if (c == -1) {
 137         fprintf(stderr, "could not accept migration connection\n");
 138         goto out2;
 139     }
 140
 141     f = qemu_fopen_socket(c);
 142     if (f == NULL) {
 143         fprintf(stderr, "could not qemu_fopen socket\n");
 144         goto out;
 145     }
 146
 147     process_incoming_migration(f);
 148     qemu_fclose(f);
 149 out:
 150     close(c);
 151 out2:
 152     qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
 153     close(s);
 154 }
 155
 156 int tcp_start_incoming_migration(const char *host_port)
 157 {
 158     struct sockaddr_in addr;
 159     int val;
 160     int s;
 161
 162     DPRINTF("Attempting to start an incoming migration\n");
 163
 164     if (parse_host_port(&addr, host_port) < 0) {
 165         fprintf(stderr, "invalid host/port combination: %s\n", host_port);
 166         return -EINVAL;
 167     }
 168
 169     s = qemu_socket(PF_INET, SOCK_STREAM, 0);
 170     if (s == -1) {
 171         return -socket_error();
 172     }
 173
 174     val = 1;
 175     setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&val, sizeof(val));
 176
 177     if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
 178         goto err;
 179     }
 180     if (listen(s, 1) == -1) {
 181         goto err;
 182     }
 183
 184     qemu_set_fd_handler2(s, NULL, tcp_accept_incoming_migration, NULL,
 185                          (void *)(intptr_t)s);
 186
 187     return 0;
 188
 189 err:
 190     close(s);
 191     return -socket_error();
 192 }