Merge branch 'upstream-merge'
[qemu-kvm.git] / migration-unix.c
blob169de886775a1d3112678ae22607d6ef1b3ec0f0
1 /*
2 * QEMU live migration via Unix Domain Sockets
4 * Copyright Red Hat, Inc. 2009
6 * Authors:
7 * Chris Lalancette <clalance@redhat.com>
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
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.
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"
23 //#define DEBUG_MIGRATION_UNIX
25 #ifdef DEBUG_MIGRATION_UNIX
26 #define DPRINTF(fmt, ...) \
27 do { printf("migration-unix: " fmt, ## __VA_ARGS__); } while (0)
28 #else
29 #define DPRINTF(fmt, ...) \
30 do { } while (0)
31 #endif
33 static int unix_errno(MigrationState *s)
35 return errno;
38 static int unix_write(MigrationState *s, const void * buf, size_t size)
40 return write(s->fd, buf, size);
43 static int unix_close(MigrationState *s)
45 int r = 0;
46 DPRINTF("unix_close\n");
47 if (s->fd != -1) {
48 if (close(s->fd) < 0) {
49 r = -errno;
51 s->fd = -1;
53 return r;
56 static void unix_wait_for_connect(void *opaque)
58 MigrationState *s = opaque;
59 int val, ret;
60 socklen_t valsize = sizeof(val);
62 DPRINTF("connect completed\n");
63 do {
64 ret = getsockopt(s->fd, SOL_SOCKET, SO_ERROR, (void *) &val, &valsize);
65 } while (ret == -1 && errno == EINTR);
67 if (ret < 0) {
68 migrate_fd_error(s);
69 return;
72 qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
74 if (val == 0)
75 migrate_fd_connect(s);
76 else {
77 DPRINTF("error connecting %d\n", val);
78 migrate_fd_error(s);
82 int unix_start_outgoing_migration(MigrationState *s, const char *path)
84 struct sockaddr_un addr;
85 int ret;
87 addr.sun_family = AF_UNIX;
88 snprintf(addr.sun_path, sizeof(addr.sun_path), "%s", path);
89 s->get_error = unix_errno;
90 s->write = unix_write;
91 s->close = unix_close;
93 s->fd = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
94 if (s->fd == -1) {
95 DPRINTF("Unable to open socket");
96 return -errno;
99 socket_set_nonblock(s->fd);
101 do {
102 ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr));
103 if (ret == -1) {
104 ret = -errno;
106 if (ret == -EINPROGRESS || ret == -EWOULDBLOCK) {
107 qemu_set_fd_handler2(s->fd, NULL, NULL, unix_wait_for_connect, s);
108 return 0;
110 } while (ret == -EINTR);
112 if (ret < 0) {
113 DPRINTF("connect failed\n");
114 migrate_fd_error(s);
115 return ret;
117 migrate_fd_connect(s);
118 return 0;
121 static void unix_accept_incoming_migration(void *opaque)
123 struct sockaddr_un addr;
124 socklen_t addrlen = sizeof(addr);
125 int s = (intptr_t)opaque;
126 QEMUFile *f;
127 int c;
129 do {
130 c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen);
131 } while (c == -1 && errno == EINTR);
133 DPRINTF("accepted migration\n");
135 if (c == -1) {
136 fprintf(stderr, "could not accept migration connection\n");
137 goto out2;
140 f = qemu_fopen_socket(c);
141 if (f == NULL) {
142 fprintf(stderr, "could not qemu_fopen socket\n");
143 goto out;
146 process_incoming_migration(f);
147 qemu_fclose(f);
148 out:
149 close(c);
150 out2:
151 qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
152 close(s);
155 int unix_start_incoming_migration(const char *path)
157 struct sockaddr_un addr;
158 int s;
159 int ret;
161 DPRINTF("Attempting to start an incoming migration\n");
163 s = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
164 if (s == -1) {
165 fprintf(stderr, "Could not open unix socket: %s\n", strerror(errno));
166 return -errno;
169 memset(&addr, 0, sizeof(addr));
170 addr.sun_family = AF_UNIX;
171 snprintf(addr.sun_path, sizeof(addr.sun_path), "%s", path);
173 unlink(addr.sun_path);
174 if (bind(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
175 ret = -errno;
176 fprintf(stderr, "bind(unix:%s): %s\n", addr.sun_path, strerror(errno));
177 goto err;
179 if (listen(s, 1) == -1) {
180 fprintf(stderr, "listen(unix:%s): %s\n", addr.sun_path,
181 strerror(errno));
182 ret = -errno;
183 goto err;
186 qemu_set_fd_handler2(s, NULL, unix_accept_incoming_migration, NULL,
187 (void *)(intptr_t)s);
189 return 0;
191 err:
192 close(s);
193 return ret;