root / migration-unix.c @ a0595d9e
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/*
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* QEMU live migration via Unix Domain Sockets
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*
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* Copyright Red Hat, Inc. 2009
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*
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* Authors:
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* Chris Lalancette <clalance@redhat.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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*
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* Contributions after 2012-01-13 are licensed under the terms of the
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* GNU GPL, version 2 or (at your option) any later version.
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*/
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#include "qemu-common.h" |
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#include "qemu_socket.h" |
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#include "migration.h" |
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#include "qemu-char.h" |
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#include "buffered_file.h" |
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#include "block.h" |
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//#define DEBUG_MIGRATION_UNIX
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#ifdef DEBUG_MIGRATION_UNIX
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#define DPRINTF(fmt, ...) \
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do { printf("migration-unix: " fmt, ## __VA_ARGS__); } while (0) |
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#else
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#define DPRINTF(fmt, ...) \
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do { } while (0) |
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#endif
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static int unix_errno(MigrationState *s) |
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{ |
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return errno;
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} |
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static int unix_write(MigrationState *s, const void * buf, size_t size) |
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{ |
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return write(s->fd, buf, size);
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} |
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static int unix_close(MigrationState *s) |
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{ |
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int r = 0; |
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DPRINTF("unix_close\n");
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if (s->fd != -1) { |
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if (close(s->fd) < 0) { |
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r = -errno; |
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} |
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s->fd = -1;
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} |
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return r;
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} |
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static void unix_wait_for_connect(void *opaque) |
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{ |
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MigrationState *s = opaque; |
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int val, ret;
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socklen_t valsize = sizeof(val);
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DPRINTF("connect completed\n");
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do {
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ret = getsockopt(s->fd, SOL_SOCKET, SO_ERROR, (void *) &val, &valsize);
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} while (ret == -1 && errno == EINTR); |
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if (ret < 0) { |
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migrate_fd_error(s); |
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return;
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} |
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qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL); |
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if (val == 0) |
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migrate_fd_connect(s); |
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else {
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DPRINTF("error connecting %d\n", val);
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migrate_fd_error(s); |
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} |
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} |
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int unix_start_outgoing_migration(MigrationState *s, const char *path) |
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{ |
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struct sockaddr_un addr;
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int ret;
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addr.sun_family = AF_UNIX; |
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snprintf(addr.sun_path, sizeof(addr.sun_path), "%s", path); |
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s->get_error = unix_errno; |
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s->write = unix_write; |
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s->close = unix_close; |
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s->fd = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
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if (s->fd == -1) { |
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DPRINTF("Unable to open socket");
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return -errno;
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} |
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socket_set_nonblock(s->fd); |
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do {
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ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr)); |
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if (ret == -1) { |
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ret = -errno; |
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} |
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if (ret == -EINPROGRESS || ret == -EWOULDBLOCK) {
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qemu_set_fd_handler2(s->fd, NULL, NULL, unix_wait_for_connect, s); |
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return 0; |
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} |
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} while (ret == -EINTR);
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if (ret < 0) { |
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DPRINTF("connect failed\n");
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migrate_fd_error(s); |
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return ret;
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} |
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migrate_fd_connect(s); |
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return 0; |
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} |
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static void unix_accept_incoming_migration(void *opaque) |
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{ |
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struct sockaddr_un addr;
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socklen_t addrlen = sizeof(addr);
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int s = (intptr_t)opaque;
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QEMUFile *f; |
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int c;
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do {
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c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen);
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} while (c == -1 && errno == EINTR); |
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DPRINTF("accepted migration\n");
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if (c == -1) { |
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fprintf(stderr, "could not accept migration connection\n");
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goto out2;
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} |
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f = qemu_fopen_socket(c); |
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if (f == NULL) { |
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fprintf(stderr, "could not qemu_fopen socket\n");
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goto out;
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} |
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process_incoming_migration(f); |
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qemu_fclose(f); |
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out:
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close(c); |
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out2:
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qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL); |
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close(s); |
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} |
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int unix_start_incoming_migration(const char *path) |
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{ |
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struct sockaddr_un addr;
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int s;
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int ret;
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DPRINTF("Attempting to start an incoming migration\n");
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s = qemu_socket(PF_UNIX, SOCK_STREAM, 0);
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if (s == -1) { |
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fprintf(stderr, "Could not open unix socket: %s\n", strerror(errno));
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return -errno;
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} |
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memset(&addr, 0, sizeof(addr)); |
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addr.sun_family = AF_UNIX; |
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snprintf(addr.sun_path, sizeof(addr.sun_path), "%s", path); |
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unlink(addr.sun_path); |
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if (bind(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) { |
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ret = -errno; |
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fprintf(stderr, "bind(unix:%s): %s\n", addr.sun_path, strerror(errno));
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goto err;
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} |
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if (listen(s, 1) == -1) { |
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fprintf(stderr, "listen(unix:%s): %s\n", addr.sun_path,
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strerror(errno)); |
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ret = -errno; |
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goto err;
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} |
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qemu_set_fd_handler2(s, NULL, unix_accept_incoming_migration, NULL, |
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(void *)(intptr_t)s);
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return 0; |
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err:
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close(s); |
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return ret;
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} |