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 "sysemu.h"
19#include "buffered_file.h"
20#include "block.h"
21
22//#define DEBUG_MIGRATION_TCP
23
24#ifdef DEBUG_MIGRATION_TCP
25#define dprintf(fmt, ...) \
26    do { printf("migration-tcp: " fmt, ## __VA_ARGS__); } while (0)
27#else
28#define dprintf(fmt, ...) \
29    do { } while (0)
30#endif
31
32static int socket_errno(FdMigrationState *s)
33{
34    return socket_error();
35}
36
37static int socket_write(FdMigrationState *s, const void * buf, size_t size)
38{
39    return send(s->fd, buf, size, 0);
40}
41
42static int tcp_close(FdMigrationState *s)
43{
44    dprintf("tcp_close\n");
45    if (s->fd != -1) {
46        close(s->fd);
47        s->fd = -1;
48    }
49    return 0;
50}
51
52
53static void tcp_wait_for_connect(void *opaque)
54{
55    FdMigrationState *s = opaque;
56    int val, ret;
57    socklen_t valsize = sizeof(val);
58
59    dprintf("connect completed\n");
60    do {
61        ret = getsockopt(s->fd, SOL_SOCKET, SO_ERROR, (void *) &val, &valsize);
62    } while (ret == -1 && (s->get_error(s)) == EINTR);
63
64    if (ret < 0) {
65        migrate_fd_error(s);
66        return;
67    }
68
69    qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
70
71    if (val == 0)
72        migrate_fd_connect(s);
73    else {
74        dprintf("error connecting %d\n", val);
75        migrate_fd_error(s);
76    }
77}
78
79MigrationState *tcp_start_outgoing_migration(const char *host_port,
80                                             int64_t bandwidth_limit,
81                                             int detach)
82{
83    struct sockaddr_in addr;
84    FdMigrationState *s;
85    int ret;
86
87    if (parse_host_port(&addr, host_port) < 0)
88        return NULL;
89
90    s = qemu_mallocz(sizeof(*s));
91
92    s->get_error = socket_errno;
93    s->write = socket_write;
94    s->close = tcp_close;
95    s->mig_state.cancel = migrate_fd_cancel;
96    s->mig_state.get_status = migrate_fd_get_status;
97    s->mig_state.release = migrate_fd_release;
98
99    s->state = MIG_STATE_ACTIVE;
100    s->mon_resume = NULL;
101    s->bandwidth_limit = bandwidth_limit;
102    s->fd = socket(PF_INET, SOCK_STREAM, 0);
103    if (s->fd == -1) {
104        qemu_free(s);
105        return NULL;
106    }
107
108    socket_set_nonblock(s->fd);
109
110    if (!detach)
111        migrate_fd_monitor_suspend(s);
112
113    do {
114        ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr));
115        if (ret == -1)
116            ret = -(s->get_error(s));
117
118        if (ret == -EINPROGRESS || ret == -EWOULDBLOCK)
119            qemu_set_fd_handler2(s->fd, NULL, NULL, tcp_wait_for_connect, s);
120    } while (ret == -EINTR);
121
122    if (ret < 0 && ret != -EINPROGRESS && ret != -EWOULDBLOCK) {
123        dprintf("connect failed\n");
124        close(s->fd);
125        qemu_free(s);
126        return NULL;
127    } else if (ret >= 0)
128        migrate_fd_connect(s);
129
130    return &s->mig_state;
131}
132
133static void tcp_accept_incoming_migration(void *opaque)
134{
135    struct sockaddr_in addr;
136    socklen_t addrlen = sizeof(addr);
137    int s = (unsigned long)opaque;
138    QEMUFile *f;
139    int c, ret;
140
141    do {
142        c = accept(s, (struct sockaddr *)&addr, &addrlen);
143    } while (c == -1 && socket_error() == EINTR);
144
145    dprintf("accepted migration\n");
146
147    if (c == -1) {
148        fprintf(stderr, "could not accept migration connection\n");
149        return;
150    }
151
152    f = qemu_fopen_socket(c);
153    if (f == NULL) {
154        fprintf(stderr, "could not qemu_fopen socket\n");
155        goto out;
156    }
157
158    vm_stop(0); /* just in case */
159    ret = qemu_loadvm_state(f);
160    if (ret < 0) {
161        fprintf(stderr, "load of migration failed\n");
162        goto out_fopen;
163    }
164    qemu_announce_self();
165    dprintf("successfully loaded vm state\n");
166
167    /* we've successfully migrated, close the server socket */
168    qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
169    close(s);
170
171    vm_start();
172
173out_fopen:
174    qemu_fclose(f);
175out:
176    close(c);
177}
178
179int tcp_start_incoming_migration(const char *host_port)
180{
181    struct sockaddr_in addr;
182    int val;
183    int s;
184
185    if (parse_host_port(&addr, host_port) < 0) {
186        fprintf(stderr, "invalid host/port combination: %s\n", host_port);
187        return -EINVAL;
188    }
189
190    s = socket(PF_INET, SOCK_STREAM, 0);
191    if (s == -1)
192        return -socket_error();
193
194    val = 1;
195    setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&val, sizeof(val));
196
197    if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1)
198        goto err;
199
200    if (listen(s, 1) == -1)
201        goto err;
202
203    qemu_set_fd_handler2(s, NULL, tcp_accept_incoming_migration, NULL,
204                         (void *)(unsigned long)s);
205
206    return 0;
207
208err:
209    close(s);
210    return -socket_error();
211}
212