/*

* Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>

*

* Network Block Device

*

* This program is free software; you can redistribute it and/or modify

* it under the terms of the GNU General Public License as published by

* the Free Software Foundation; under version 2 of the License.

*

* This program is distributed in the hope that it will be useful,

* but WITHOUT ANY WARRANTY; without even the implied warranty of

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

* GNU General Public License for more details.

*

* You should have received a copy of the GNU General Public License

* along with this program; if not, see <http://www.gnu.org/licenses/>.

*/

#include "qemu/osdep.h"

#include <getopt.h>

#include <libgen.h>

#include <pthread.h>

#include "qapi/error.h"

#include "qemu/cutils.h"

#include "sysemu/block-backend.h"

#include "block/block_int.h"

#include "block/nbd.h"

#include "qemu/main-loop.h"

#include "qemu/option.h"

#include "qemu/error-report.h"

#include "qemu/config-file.h"

#include "qemu/bswap.h"

#include "qemu/log.h"

#include "qemu/systemd.h"

#include "block/snapshot.h"

#include "qapi/qmp/qdict.h"

#include "qapi/qmp/qstring.h"

#include "qom/object_interfaces.h"

#include "io/channel-socket.h"

#include "io/net-listener.h"

#include "crypto/init.h"

#include "trace/control.h"

#include "qemu-version.h"

#define SOCKET_PATH "/var/lock/qemu-nbd-%s"

#define QEMU_NBD_OPT_CACHE 256

#define QEMU_NBD_OPT_AIO 257

#define QEMU_NBD_OPT_DISCARD 258

#define QEMU_NBD_OPT_DETECT_ZEROES 259

#define QEMU_NBD_OPT_OBJECT 260

#define QEMU_NBD_OPT_TLSCREDS 261

#define QEMU_NBD_OPT_IMAGE_OPTS 262

#define QEMU_NBD_OPT_FORK 263

#define MBR_SIZE 512

static NBDExport *exp;

static int verbose;

static char *srcpath;

static SocketAddress *saddr;

static int persistent = 0;

static enum { RUNNING, TERMINATE, TERMINATING, TERMINATED } state;

static int shared = 1;

static int nb_fds;

static QIONetListener *server;

static QCryptoTLSCreds *tlscreds;

static void usage(const char *name)

{

(printf) (

"Usage: %s [OPTIONS] FILE\n"

"QEMU Disk Network Block Device Server\n"

"\n"

" -h, --help display this help and exit\n"

" -V, --version output version information and exit\n"

"\n"

"Connection properties:\n"

" -p, --port=PORT port to listen on (default `%d')\n"

" -b, --bind=IFACE interface to bind to (default `0.0.0.0')\n"

" -k, --socket=PATH path to the unix socket\n"

" (default '"SOCKET_PATH"')\n"

" -e, --shared=NUM device can be shared by NUM clients (default '1')\n"

" -t, --persistent don't exit on the last connection\n"

" -v, --verbose display extra debugging information\n"

" -x, --export-name=NAME expose export by name (default is empty string)\n"

" -D, --description=TEXT export a human-readable description\n"

"\n"

"Exposing part of the image:\n"

" -o, --offset=OFFSET offset into the image\n"

" -P, --partition=NUM only expose partition NUM\n"

"\n"

"General purpose options:\n"

" --object type,id=ID,... define an object such as 'secret' for providing\n"

" passwords and/or encryption keys\n"

" --tls-creds=ID use id of an earlier --object to provide TLS\n"

" -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"

" specify tracing options\n"

" --fork fork off the server process and exit the parent\n"

" once the server is running\n"

#ifdef __linux__

"Kernel NBD client support:\n"

" -c, --connect=DEV connect FILE to the local NBD device DEV\n"

" -d, --disconnect disconnect the specified device\n"

"\n"

#endif

"\n"

"Block device options:\n"

" -f, --format=FORMAT set image format (raw, qcow2, ...)\n"

" -r, --read-only export read-only\n"

" -s, --snapshot use FILE as an external snapshot, create a temporary\n"

" file with backing_file=FILE, redirect the write to\n"

" the temporary one\n"

" -l, --load-snapshot=SNAPSHOT_PARAM\n"

" load an internal snapshot inside FILE and export it\n"

" as an read-only device, SNAPSHOT_PARAM format is\n"

" 'snapshot.id=[ID],snapshot.name=[NAME]', or\n"

" '[ID_OR_NAME]'\n"

" -n, --nocache disable host cache\n"

" --cache=MODE set cache mode (none, writeback, ...)\n"

" --aio=MODE set AIO mode (native or threads)\n"

" --discard=MODE set discard mode (ignore, unmap)\n"

" --detect-zeroes=MODE set detect-zeroes mode (off, on, unmap)\n"

" --image-opts treat FILE as a full set of image options\n"

"\n"

QEMU_HELP_BOTTOM "\n"

, name, NBD_DEFAULT_PORT, "DEVICE");

}

static void version(const char *name)

{

printf(

"%s " QEMU_FULL_VERSION "\n"

"Written by Anthony Liguori.\n"

"\n"

QEMU_COPYRIGHT "\n"

"This is free software; see the source for copying conditions. There is NO\n"

"warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"

, name);

}

struct partition_record

};

static void read_partition(uint8_t *p, struct partition_record *r)

{

r->bootable = p[0];

r->start_head = p[1];

r->start_cylinder = p[3] | ((p[2] << 2) & 0x0300);

r->start_sector = p[2] & 0x3f;

r->system = p[4];

r->end_head = p[5];

r->end_cylinder = p[7] | ((p[6] << 2) & 0x300);

r->end_sector = p[6] & 0x3f;

r->start_sector_abs = ldl_le_p(p + 8);

r->nb_sectors_abs = ldl_le_p(p + 12);

}

static int find_partition(BlockBackend *blk, int partition,

off_t *offset, off_t *size)

{

struct partition_record mbr[4];

uint8_t data[MBR_SIZE];

int i;

int ext_partnum = 4;

int ret;

ret = blk_pread(blk, 0, data, sizeof(data));

if (ret < 0) {

error_report("error while reading: %s", strerror(-ret));

exit(EXIT_FAILURE);

}

if (data[510] != 0x55 || data[511] != 0xaa) {

return -EINVAL;

}

for (i = 0; i < 4; i++) {

read_partition(&data[446 + 16 * i], &mbr[i]);

if (!mbr[i].system || !mbr[i].nb_sectors_abs) {

continue;

}

if (mbr[i].system == 0xF || mbr[i].system == 0x5) {

struct partition_record ext[4];

uint8_t data1[MBR_SIZE];

int j;

ret = blk_pread(blk, mbr[i].start_sector_abs * MBR_SIZE,

data1, sizeof(data1));

if (ret < 0) {

error_report("error while reading: %s", strerror(-ret));

exit(EXIT_FAILURE);

}

for (j = 0; j < 4; j++) {

read_partition(&data1[446 + 16 * j], &ext[j]);

if (!ext[j].system || !ext[j].nb_sectors_abs) {

continue;

}

if ((ext_partnum + j + 1) == partition) {

*offset = (uint64_t)ext[j].start_sector_abs << 9;

*size = (uint64_t)ext[j].nb_sectors_abs << 9;

return 0;

}

}

ext_partnum += 4;

} else if ((i + 1) == partition) {

*offset = (uint64_t)mbr[i].start_sector_abs << 9;

*size = (uint64_t)mbr[i].nb_sectors_abs << 9;

return 0;

}

}

return -ENOENT;

}

static void termsig_handler(int signum)

{

atomic_cmpxchg(&state, RUNNING, TERMINATE);

qemu_notify_event();

}

static void *show_parts(void *arg)

{

char *device = arg;

int nbd;

/* linux just needs an open() to trigger

* the partition table update

* but remember to load the module with max_part != 0 :

* modprobe nbd max_part=63

*/

nbd = open(device, O_RDWR);

if (nbd >= 0) {

close(nbd);

}

return NULL;

}

static void *nbd_client_thread(void *arg)

{

char *device = arg;

NBDExportInfo info = { .request_sizes = false, };

QIOChannelSocket *sioc;

int fd;

int ret;

pthread_t show_parts_thread;

Error *local_error = NULL;

sioc = qio_channel_socket_new();

if (qio_channel_socket_connect_sync(sioc,

saddr,

&local_error) < 0) {

error_report_err(local_error);

goto out;

}

ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), NULL,

NULL, NULL, NULL, &info, &local_error);

if (ret < 0) {

if (local_error) {

error_report_err(local_error);

}

goto out_socket;

}

fd = open(device, O_RDWR);

if (fd < 0) {

/* Linux-only, we can use %m in printf. */

error_report("Failed to open %s: %m", device);

goto out_socket;

}

ret = nbd_init(fd, sioc, &info, &local_error);

if (ret < 0) {

error_report_err(local_error);

goto out_fd;

}

/* update partition table */

pthread_create(&show_parts_thread, NULL, show_parts, device);

if (verbose) {

fprintf(stderr, "NBD device %s is now connected to %s\n",

device, srcpath);

} else {

/* Close stderr so that the qemu-nbd process exits. */

dup2(STDOUT_FILENO, STDERR_FILENO);

}

ret = nbd_client(fd);

if (ret) {

goto out_fd;

}

close(fd);

object_unref(OBJECT(sioc));

kill(getpid(), SIGTERM);

return (void *) EXIT_SUCCESS;

out_fd:

close(fd);

out_socket:

object_unref(OBJECT(sioc));

out:

kill(getpid(), SIGTERM);

return (void *) EXIT_FAILURE;

}

static int nbd_can_accept(void)

{

return state == RUNNING && nb_fds < shared;

}

static void nbd_export_closed(NBDExport *exp)

{

assert(state == TERMINATING);

state = TERMINATED;

}

static void nbd_update_server_watch(void);

static void nbd_client_closed(NBDClient *client, bool negotiated)

{

nb_fds--;

if (negotiated && nb_fds == 0 && !persistent && state == RUNNING) {

state = TERMINATE;

}

nbd_update_server_watch();

nbd_client_put(client);

}

static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc,

gpointer opaque)

{

if (state >= TERMINATE) {

return;

}

nb_fds++;

nbd_update_server_watch();

nbd_client_new(cioc, tlscreds, NULL, nbd_client_closed);

}

static void nbd_update_server_watch(void)

{

if (nbd_can_accept()) {

qio_net_listener_set_client_func(server, nbd_accept, NULL, NULL);

} else {

qio_net_listener_set_client_func(server, NULL, NULL, NULL);

}

}

static SocketAddress *nbd_build_socket_address(const char *sockpath,

const char *bindto,

const char *port)

{

SocketAddress *saddr;

saddr = g_new0(SocketAddress, 1);

if (sockpath) {

saddr->type = SOCKET_ADDRESS_TYPE_UNIX;

saddr->u.q_unix.path = g_strdup(sockpath);

} else {

InetSocketAddress *inet;

saddr->type = SOCKET_ADDRESS_TYPE_INET;

inet = &saddr->u.inet;

inet->host = g_strdup(bindto);

if (port) {

inet->port = g_strdup(port);

} else {

inet->port = g_strdup_printf("%d", NBD_DEFAULT_PORT);

}

}

return saddr;

}

static QemuOptsList file_opts = {

.name = "file",

.implied_opt_name = "file",

.head = QTAILQ_HEAD_INITIALIZER(file_opts.head),

.desc = {

/* no elements => accept any params */

{ /* end of list */ }

},

};

static QemuOptsList qemu_object_opts = {

.name = "object",

.implied_opt_name = "qom-type",

.head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),

.desc = {

{ }

},

};

static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)

{

Object *obj;

QCryptoTLSCreds *creds;

obj = object_resolve_path_component(

object_get_objects_root(), id);

if (!obj) {

error_setg(errp, "No TLS credentials with id '%s'",

id);

return NULL;

}

creds = (QCryptoTLSCreds *)

object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS);

if (!creds) {

error_setg(errp, "Object with id '%s' is not TLS credentials",

id);

return NULL;

}

if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {

error_setg(errp,

"Expecting TLS credentials with a server endpoint");

return NULL;

}

object_ref(obj);

return creds;

}

static void setup_address_and_port(const char **address, const char **port)

{

if (*address == NULL) {

*address = "0.0.0.0";

}

if (*port == NULL) {

*port = stringify(NBD_DEFAULT_PORT);

}

}

/*

* Check socket parameters compatibility when socket activation is used.

*/

static const char *socket_activation_validate_opts(const char *device,

const char *sockpath,

const char *address,

const char *port)

{

if (device != NULL) {

return "NBD device can't be set when using socket activation";

}

if (sockpath != NULL) {

return "Unix socket can't be set when using socket activation";

}

if (address != NULL) {

return "The interface can't be set when using socket activation";

}

if (port != NULL) {

return "TCP port number can't be set when using socket activation";

}

return NULL;

}

static void qemu_nbd_shutdown(void)

{

job_cancel_sync_all();

bdrv_close_all();

}

int main(int argc, char **argv)

{

BlockBackend *blk;

BlockDriverState *bs;

off_t dev_offset = 0;

uint16_t nbdflags = 0;

bool disconnect = false;

const char *bindto = NULL;

const char *port = NULL;

char *sockpath = NULL;

char *device = NULL;

off_t fd_size;

QemuOpts *sn_opts = NULL;

const char *sn_id_or_name = NULL;

const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:D:";

struct option lopt[] = {

{ "help", no_argument, NULL, 'h' },

{ "version", no_argument, NULL, 'V' },

{ "bind", required_argument, NULL, 'b' },

{ "port", required_argument, NULL, 'p' },

{ "socket", required_argument, NULL, 'k' },

{ "offset", required_argument, NULL, 'o' },

{ "read-only", no_argument, NULL, 'r' },

{ "partition", required_argument, NULL, 'P' },

{ "connect", required_argument, NULL, 'c' },

{ "disconnect", no_argument, NULL, 'd' },

{ "snapshot", no_argument, NULL, 's' },

{ "load-snapshot", required_argument, NULL, 'l' },

{ "nocache", no_argument, NULL, 'n' },

{ "cache", required_argument, NULL, QEMU_NBD_OPT_CACHE },

{ "aio", required_argument, NULL, QEMU_NBD_OPT_AIO },

{ "discard", required_argument, NULL, QEMU_NBD_OPT_DISCARD },

{ "detect-zeroes", required_argument, NULL,

QEMU_NBD_OPT_DETECT_ZEROES },

{ "shared", required_argument, NULL, 'e' },

{ "format", required_argument, NULL, 'f' },

{ "persistent", no_argument, NULL, 't' },

{ "verbose", no_argument, NULL, 'v' },

{ "object", required_argument, NULL, QEMU_NBD_OPT_OBJECT },

{ "export-name", required_argument, NULL, 'x' },

{ "description", required_argument, NULL, 'D' },

{ "tls-creds", required_argument, NULL, QEMU_NBD_OPT_TLSCREDS },

{ "image-opts", no_argument, NULL, QEMU_NBD_OPT_IMAGE_OPTS },

{ "trace", required_argument, NULL, 'T' },

{ "fork", no_argument, NULL, QEMU_NBD_OPT_FORK },

{ NULL, 0, NULL, 0 }

};

int ch;

int opt_ind = 0;

char *end;

int flags = BDRV_O_RDWR;

int partition = -1;

int ret = 0;

bool seen_cache = false;

bool seen_discard = false;

bool seen_aio = false;

pthread_t client_thread;

const char *fmt = NULL;

Error *local_err = NULL;

BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;

QDict *options = NULL;

const char *export_name = ""; /* Default export name */

const char *export_description = NULL;

const char *tlscredsid = NULL;

bool imageOpts = false;

bool writethrough = true;

char *trace_file = NULL;

bool fork_process = false;

int old_stderr = -1;

unsigned socket_activation;

/* The client thread uses SIGTERM to interrupt the server. A signal

* handler ensures that "qemu-nbd -v -c" exits with a nice status code.

*/

struct sigaction sa_sigterm;

memset(&sa_sigterm, 0, sizeof(sa_sigterm));

sa_sigterm.sa_handler = termsig_handler;

sigaction(SIGTERM, &sa_sigterm, NULL);

#ifdef CONFIG_POSIX

signal(SIGPIPE, SIG_IGN);

#endif

module_call_init(MODULE_INIT_TRACE);

qcrypto_init(&error_fatal);

module_call_init(MODULE_INIT_QOM);

qemu_add_opts(&qemu_object_opts);

qemu_add_opts(&qemu_trace_opts);

qemu_init_exec_dir(argv[0]);

while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {

switch (ch) {

case 's':

flags |= BDRV_O_SNAPSHOT;

break;

case 'n':

optarg = (char *) "none";

/* fallthrough */

case QEMU_NBD_OPT_CACHE:

if (seen_cache) {

error_report("-n and --cache can only be specified once");

exit(EXIT_FAILURE);

}

seen_cache = true;

if (bdrv_parse_cache_mode(optarg, &flags, &writethrough) == -1) {

error_report("Invalid cache mode `%s'", optarg);

exit(EXIT_FAILURE);

}

break;

case QEMU_NBD_OPT_AIO:

if (seen_aio) {

error_report("--aio can only be specified once");

exit(EXIT_FAILURE);

}

seen_aio = true;

if (!strcmp(optarg, "native")) {

flags |= BDRV_O_NATIVE_AIO;

} else if (!strcmp(optarg, "threads")) {

/* this is the default */

} else {

error_report("invalid aio mode `%s'", optarg);

exit(EXIT_FAILURE);

}

break;

case QEMU_NBD_OPT_DISCARD:

if (seen_discard) {

error_report("--discard can only be specified once");

exit(EXIT_FAILURE);

}

seen_discard = true;

if (bdrv_parse_discard_flags(optarg, &flags) == -1) {

error_report("Invalid discard mode `%s'", optarg);

exit(EXIT_FAILURE);

}

break;

case QEMU_NBD_OPT_DETECT_ZEROES:

detect_zeroes =

qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup,

optarg,

BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,

&local_err);

if (local_err) {

error_reportf_err(local_err,

"Failed to parse detect_zeroes mode: ");

exit(EXIT_FAILURE);

}

if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&

!(flags & BDRV_O_UNMAP)) {

error_report("setting detect-zeroes to unmap is not allowed "

"without setting discard operation to unmap");

exit(EXIT_FAILURE);

}

break;

case 'b':

bindto = optarg;

break;

case 'p':

port = optarg;

break;

case 'o':

dev_offset = strtoll (optarg, &end, 0);

if (*end) {

error_report("Invalid offset `%s'", optarg);

exit(EXIT_FAILURE);

}

if (dev_offset < 0) {

error_report("Offset must be positive `%s'", optarg);

exit(EXIT_FAILURE);

}

break;

case 'l':

if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {

sn_opts = qemu_opts_parse_noisily(&internal_snapshot_opts,

optarg, false);

if (!sn_opts) {

error_report("Failed in parsing snapshot param `%s'",

optarg);

exit(EXIT_FAILURE);

}

} else {

sn_id_or_name = optarg;

}

/* fall through */

case 'r':

nbdflags |= NBD_FLAG_READ_ONLY;

flags &= ~BDRV_O_RDWR;

break;

case 'P':

partition = strtol(optarg, &end, 0);

if (*end) {

error_report("Invalid partition `%s'", optarg);

exit(EXIT_FAILURE);

}

if (partition < 1 || partition > 8) {

error_report("Invalid partition %d", partition);

exit(EXIT_FAILURE);

}

break;

case 'k':

sockpath = optarg;

if (sockpath[0] != '/') {

error_report("socket path must be absolute");

exit(EXIT_FAILURE);

}

break;

case 'd':

disconnect = true;

break;

case 'c':

device = optarg;

break;

case 'e':

shared = strtol(optarg, &end, 0);

if (*end) {

error_report("Invalid shared device number '%s'", optarg);

exit(EXIT_FAILURE);

}

if (shared < 1) {

error_report("Shared device number must be greater than 0");

exit(EXIT_FAILURE);

}

break;

case 'f':

fmt = optarg;

break;

case 't':

persistent = 1;

break;

case 'x':

export_name = optarg;

break;

case 'D':

export_description = optarg;

break;

case 'v':

verbose = 1;

break;

case 'V':

version(argv[0]);

exit(0);

break;

case 'h':

usage(argv[0]);

exit(0);

break;

case '?':

error_report("Try `%s --help' for more information.", argv[0]);

exit(EXIT_FAILURE);

case QEMU_NBD_OPT_OBJECT: {

QemuOpts *opts;

opts = qemu_opts_parse_noisily(&qemu_object_opts,

optarg, true);

if (!opts) {

exit(EXIT_FAILURE);

}

} break;

case QEMU_NBD_OPT_TLSCREDS:

tlscredsid = optarg;

break;

case QEMU_NBD_OPT_IMAGE_OPTS:

imageOpts = true;

break;

case 'T':

g_free(trace_file);

trace_file = trace_opt_parse(optarg);

break;

case QEMU_NBD_OPT_FORK:

fork_process = true;

break;

}

}

if ((argc - optind) != 1) {

error_report("Invalid number of arguments");

error_printf("Try `%s --help' for more information.\n", argv[0]);

exit(EXIT_FAILURE);

}

qemu_opts_foreach(&qemu_object_opts,

user_creatable_add_opts_foreach,

NULL, &error_fatal);

if (!trace_init_backends()) {

exit(1);

}

trace_init_file(trace_file);

qemu_set_log(LOG_TRACE);

socket_activation = check_socket_activation();

if (socket_activation == 0) {

setup_address_and_port(&bindto, &port);

} else {

/* Using socket activation - check user didn't use -p etc. */

const char *err_msg = socket_activation_validate_opts(device, sockpath,

bindto, port);

if (err_msg != NULL) {

error_report("%s", err_msg);

exit(EXIT_FAILURE);

}

/* qemu-nbd can only listen on a single socket. */

if (socket_activation > 1) {

error_report("qemu-nbd does not support socket activation with %s > 1",

"LISTEN_FDS");

exit(EXIT_FAILURE);

}

}

if (tlscredsid) {

if (sockpath) {

error_report("TLS is only supported with IPv4/IPv6");

exit(EXIT_FAILURE);

}

if (device) {

error_report("TLS is not supported with a host device");

exit(EXIT_FAILURE);

}

tlscreds = nbd_get_tls_creds(tlscredsid, &local_err);

if (local_err) {

error_report("Failed to get TLS creds %s",

error_get_pretty(local_err));

exit(EXIT_FAILURE);

}

}

if (disconnect) {

int nbdfd = open(argv[optind], O_RDWR);

if (nbdfd < 0) {

error_report("Cannot open %s: %s", argv[optind],

strerror(errno));

exit(EXIT_FAILURE);

}

nbd_disconnect(nbdfd);

close(nbdfd);

printf("%s disconnected\n", argv[optind]);

return 0;

}

if ((device && !verbose) || fork_process) {

int stderr_fd[2];

pid_t pid;

int ret;

if (qemu_pipe(stderr_fd) < 0) {

error_report("Error setting up communication pipe: %s",

strerror(errno));

exit(EXIT_FAILURE);

}

/* Now daemonize, but keep a communication channel open to

* print errors and exit with the proper status code.

*/

pid = fork();

if (pid < 0) {

error_report("Failed to fork: %s", strerror(errno));

exit(EXIT_FAILURE);

} else if (pid == 0) {

close(stderr_fd[0]);

ret = qemu_daemon(1, 0);

/* Temporarily redirect stderr to the parent's pipe... */

old_stderr = dup(STDERR_FILENO);

dup2(stderr_fd[1], STDERR_FILENO);

if (ret < 0) {

error_report("Failed to daemonize: %s", strerror(errno));

exit(EXIT_FAILURE);

}

/* ... close the descriptor we inherited and go on. */

close(stderr_fd[1]);

} else {

bool errors = false;

char *buf;

/* In the parent. Print error messages from the child until

* it closes the pipe.

*/

close(stderr_fd[1]);

buf = g_malloc(1024);

while ((ret = read(stderr_fd[0], buf, 1024)) > 0) {

errors = true;

ret = qemu_write_full(STDERR_FILENO, buf, ret);

if (ret < 0) {

exit(EXIT_FAILURE);

}

}

if (ret < 0) {

error_report("Cannot read from daemon: %s",

strerror(errno));

exit(EXIT_FAILURE);

}

/* Usually the daemon should not print any message.

* Exit with zero status in that case.

*/

exit(errors);

}

}

if (device != NULL && sockpath == NULL) {

sockpath = g_malloc(128);

snprintf(sockpath, 128, SOCKET_PATH, basename(device));

}

server = qio_net_listener_new();

if (socket_activation == 0) {

saddr = nbd_build_socket_address(sockpath, bindto, port);

if (qio_net_listener_open_sync(server, saddr, &local_err) < 0) {

object_unref(OBJECT(server));

error_report_err(local_err);

exit(EXIT_FAILURE);

}

} else {

size_t i;

/* See comment in check_socket_activation above. */

for (i = 0; i < socket_activation; i++) {

QIOChannelSocket *sioc;

sioc = qio_channel_socket_new_fd(FIRST_SOCKET_ACTIVATION_FD + i,

&local_err);

if (sioc == NULL) {

object_unref(OBJECT(server));

error_report("Failed to use socket activation: %s",

error_get_pretty(local_err));

exit(EXIT_FAILURE);

}

qio_net_listener_add(server, sioc);

object_unref(OBJECT(sioc));

}

}

if (qemu_init_main_loop(&local_err)) {

error_report_err(local_err);

exit(EXIT_FAILURE);

}

bdrv_init();

atexit(qemu_nbd_shutdown);

srcpath = argv[optind];

if (imageOpts) {

QemuOpts *opts;

if (fmt) {

error_report("--image-opts and -f are mutually exclusive");

exit(EXIT_FAILURE);

}

opts = qemu_opts_parse_noisily(&file_opts, srcpath, true);

if (!opts) {

qemu_opts_reset(&file_opts);

exit(EXIT_FAILURE);

}

options = qemu_opts_to_qdict(opts, NULL);

qemu_opts_reset(&file_opts);

blk = blk_new_open(NULL, NULL, options, flags, &local_err);

} else {

if (fmt) {

options = qdict_new();

qdict_put_str(options, "driver", fmt);

}

blk = blk_new_open(srcpath, NULL, options, flags, &local_err);

}

if (!blk) {

error_reportf_err(local_err, "Failed to blk_new_open '%s': ",

argv[optind]);

exit(EXIT_FAILURE);

}

bs = blk_bs(blk);

blk_set_enable_write_cache(blk, !writethrough);

if (sn_opts) {

ret = bdrv_snapshot_load_tmp(bs,

qemu_opt_get(sn_opts, SNAPSHOT_OPT_ID),

qemu_opt_get(sn_opts, SNAPSHOT_OPT_NAME),

&local_err);

} else if (sn_id_or_name) {

ret = bdrv_snapshot_load_tmp_by_id_or_name(bs, sn_id_or_name,

&local_err);

}

if (ret < 0) {

error_reportf_err(local_err, "Failed to load snapshot: ");

exit(EXIT_FAILURE);

}

bs->detect_zeroes = detect_zeroes;

fd_size = blk_getlength(blk);

if (fd_size < 0) {

error_report("Failed to determine the image length: %s",

strerror(-fd_size));

exit(EXIT_FAILURE);

}

if (dev_offset >= fd_size) {

error_report("Offset (%lld) has to be smaller than the image size "

"(%lld)",

(long long int)dev_offset, (long long int)fd_size);

exit(EXIT_FAILURE);

}

fd_size -= dev_offset;

if (partition != -1) {

ret = find_partition(blk, partition, &dev_offset, &fd_size);

if (ret < 0) {

error_report("Could not find partition %d: %s", partition,

strerror(-ret));

exit(EXIT_FAILURE);

}

}