mirror of
https://github.com/qemu/qemu.git
synced 2024-12-12 05:03:42 +08:00
e31d802479
The NBD spec, and even our code comment, says that if the client
asks for NBD_OPT_LIST_META_CONTEXT with 0 queries, then we should
reply with (a possibly-compressed representation of) ALL contexts
that we are willing to let them try. But commit 3d068aff
forgot
to advertise qemu:dirty-bitmap:FOO.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20181130023232.3079982-2-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2474 lines
77 KiB
C
2474 lines
77 KiB
C
/*
|
|
* Copyright (C) 2016-2018 Red Hat, Inc.
|
|
* Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
|
|
*
|
|
* Network Block Device Server Side
|
|
*
|
|
* 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 "qapi/error.h"
|
|
#include "trace.h"
|
|
#include "nbd-internal.h"
|
|
|
|
#define NBD_META_ID_BASE_ALLOCATION 0
|
|
#define NBD_META_ID_DIRTY_BITMAP 1
|
|
|
|
/* NBD_MAX_BITMAP_EXTENTS: 1 mb of extents data. An empirical
|
|
* constant. If an increase is needed, note that the NBD protocol
|
|
* recommends no larger than 32 mb, so that the client won't consider
|
|
* the reply as a denial of service attack. */
|
|
#define NBD_MAX_BITMAP_EXTENTS (0x100000 / 8)
|
|
|
|
static int system_errno_to_nbd_errno(int err)
|
|
{
|
|
switch (err) {
|
|
case 0:
|
|
return NBD_SUCCESS;
|
|
case EPERM:
|
|
case EROFS:
|
|
return NBD_EPERM;
|
|
case EIO:
|
|
return NBD_EIO;
|
|
case ENOMEM:
|
|
return NBD_ENOMEM;
|
|
#ifdef EDQUOT
|
|
case EDQUOT:
|
|
#endif
|
|
case EFBIG:
|
|
case ENOSPC:
|
|
return NBD_ENOSPC;
|
|
case EOVERFLOW:
|
|
return NBD_EOVERFLOW;
|
|
case ESHUTDOWN:
|
|
return NBD_ESHUTDOWN;
|
|
case EINVAL:
|
|
default:
|
|
return NBD_EINVAL;
|
|
}
|
|
}
|
|
|
|
/* Definitions for opaque data types */
|
|
|
|
typedef struct NBDRequestData NBDRequestData;
|
|
|
|
struct NBDRequestData {
|
|
QSIMPLEQ_ENTRY(NBDRequestData) entry;
|
|
NBDClient *client;
|
|
uint8_t *data;
|
|
bool complete;
|
|
};
|
|
|
|
struct NBDExport {
|
|
int refcount;
|
|
void (*close)(NBDExport *exp);
|
|
|
|
BlockBackend *blk;
|
|
char *name;
|
|
char *description;
|
|
off_t dev_offset;
|
|
off_t size;
|
|
uint16_t nbdflags;
|
|
QTAILQ_HEAD(, NBDClient) clients;
|
|
QTAILQ_ENTRY(NBDExport) next;
|
|
|
|
AioContext *ctx;
|
|
|
|
BlockBackend *eject_notifier_blk;
|
|
Notifier eject_notifier;
|
|
|
|
BdrvDirtyBitmap *export_bitmap;
|
|
char *export_bitmap_context;
|
|
};
|
|
|
|
static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports);
|
|
|
|
/* NBDExportMetaContexts represents a list of contexts to be exported,
|
|
* as selected by NBD_OPT_SET_META_CONTEXT. Also used for
|
|
* NBD_OPT_LIST_META_CONTEXT. */
|
|
typedef struct NBDExportMetaContexts {
|
|
NBDExport *exp;
|
|
bool valid; /* means that negotiation of the option finished without
|
|
errors */
|
|
bool base_allocation; /* export base:allocation context (block status) */
|
|
bool bitmap; /* export qemu:dirty-bitmap:<export bitmap name> */
|
|
} NBDExportMetaContexts;
|
|
|
|
struct NBDClient {
|
|
int refcount;
|
|
void (*close_fn)(NBDClient *client, bool negotiated);
|
|
|
|
NBDExport *exp;
|
|
QCryptoTLSCreds *tlscreds;
|
|
char *tlsaclname;
|
|
QIOChannelSocket *sioc; /* The underlying data channel */
|
|
QIOChannel *ioc; /* The current I/O channel which may differ (eg TLS) */
|
|
|
|
Coroutine *recv_coroutine;
|
|
|
|
CoMutex send_lock;
|
|
Coroutine *send_coroutine;
|
|
|
|
QTAILQ_ENTRY(NBDClient) next;
|
|
int nb_requests;
|
|
bool closing;
|
|
|
|
bool structured_reply;
|
|
NBDExportMetaContexts export_meta;
|
|
|
|
uint32_t opt; /* Current option being negotiated */
|
|
uint32_t optlen; /* remaining length of data in ioc for the option being
|
|
negotiated now */
|
|
};
|
|
|
|
static void nbd_client_receive_next_request(NBDClient *client);
|
|
|
|
/* Basic flow for negotiation
|
|
|
|
Server Client
|
|
Negotiate
|
|
|
|
or
|
|
|
|
Server Client
|
|
Negotiate #1
|
|
Option
|
|
Negotiate #2
|
|
|
|
----
|
|
|
|
followed by
|
|
|
|
Server Client
|
|
Request
|
|
Response
|
|
Request
|
|
Response
|
|
...
|
|
...
|
|
Request (type == 2)
|
|
|
|
*/
|
|
|
|
static inline void set_be_option_rep(NBDOptionReply *rep, uint32_t option,
|
|
uint32_t type, uint32_t length)
|
|
{
|
|
stq_be_p(&rep->magic, NBD_REP_MAGIC);
|
|
stl_be_p(&rep->option, option);
|
|
stl_be_p(&rep->type, type);
|
|
stl_be_p(&rep->length, length);
|
|
}
|
|
|
|
/* Send a reply header, including length, but no payload.
|
|
* Return -errno on error, 0 on success. */
|
|
static int nbd_negotiate_send_rep_len(NBDClient *client, uint32_t type,
|
|
uint32_t len, Error **errp)
|
|
{
|
|
NBDOptionReply rep;
|
|
|
|
trace_nbd_negotiate_send_rep_len(client->opt, nbd_opt_lookup(client->opt),
|
|
type, nbd_rep_lookup(type), len);
|
|
|
|
assert(len < NBD_MAX_BUFFER_SIZE);
|
|
|
|
set_be_option_rep(&rep, client->opt, type, len);
|
|
return nbd_write(client->ioc, &rep, sizeof(rep), errp);
|
|
}
|
|
|
|
/* Send a reply header with default 0 length.
|
|
* Return -errno on error, 0 on success. */
|
|
static int nbd_negotiate_send_rep(NBDClient *client, uint32_t type,
|
|
Error **errp)
|
|
{
|
|
return nbd_negotiate_send_rep_len(client, type, 0, errp);
|
|
}
|
|
|
|
/* Send an error reply.
|
|
* Return -errno on error, 0 on success. */
|
|
static int GCC_FMT_ATTR(4, 0)
|
|
nbd_negotiate_send_rep_verr(NBDClient *client, uint32_t type,
|
|
Error **errp, const char *fmt, va_list va)
|
|
{
|
|
char *msg;
|
|
int ret;
|
|
size_t len;
|
|
|
|
msg = g_strdup_vprintf(fmt, va);
|
|
len = strlen(msg);
|
|
assert(len < 4096);
|
|
trace_nbd_negotiate_send_rep_err(msg);
|
|
ret = nbd_negotiate_send_rep_len(client, type, len, errp);
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
if (nbd_write(client->ioc, msg, len, errp) < 0) {
|
|
error_prepend(errp, "write failed (error message): ");
|
|
ret = -EIO;
|
|
} else {
|
|
ret = 0;
|
|
}
|
|
|
|
out:
|
|
g_free(msg);
|
|
return ret;
|
|
}
|
|
|
|
/* Send an error reply.
|
|
* Return -errno on error, 0 on success. */
|
|
static int GCC_FMT_ATTR(4, 5)
|
|
nbd_negotiate_send_rep_err(NBDClient *client, uint32_t type,
|
|
Error **errp, const char *fmt, ...)
|
|
{
|
|
va_list va;
|
|
int ret;
|
|
|
|
va_start(va, fmt);
|
|
ret = nbd_negotiate_send_rep_verr(client, type, errp, fmt, va);
|
|
va_end(va);
|
|
return ret;
|
|
}
|
|
|
|
/* Drop remainder of the current option, and send a reply with the
|
|
* given error type and message. Return -errno on read or write
|
|
* failure; or 0 if connection is still live. */
|
|
static int GCC_FMT_ATTR(4, 0)
|
|
nbd_opt_vdrop(NBDClient *client, uint32_t type, Error **errp,
|
|
const char *fmt, va_list va)
|
|
{
|
|
int ret = nbd_drop(client->ioc, client->optlen, errp);
|
|
|
|
client->optlen = 0;
|
|
if (!ret) {
|
|
ret = nbd_negotiate_send_rep_verr(client, type, errp, fmt, va);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int GCC_FMT_ATTR(4, 5)
|
|
nbd_opt_drop(NBDClient *client, uint32_t type, Error **errp,
|
|
const char *fmt, ...)
|
|
{
|
|
int ret;
|
|
va_list va;
|
|
|
|
va_start(va, fmt);
|
|
ret = nbd_opt_vdrop(client, type, errp, fmt, va);
|
|
va_end(va);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int GCC_FMT_ATTR(3, 4)
|
|
nbd_opt_invalid(NBDClient *client, Error **errp, const char *fmt, ...)
|
|
{
|
|
int ret;
|
|
va_list va;
|
|
|
|
va_start(va, fmt);
|
|
ret = nbd_opt_vdrop(client, NBD_REP_ERR_INVALID, errp, fmt, va);
|
|
va_end(va);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* Read size bytes from the unparsed payload of the current option.
|
|
* Return -errno on I/O error, 0 if option was completely handled by
|
|
* sending a reply about inconsistent lengths, or 1 on success. */
|
|
static int nbd_opt_read(NBDClient *client, void *buffer, size_t size,
|
|
Error **errp)
|
|
{
|
|
if (size > client->optlen) {
|
|
return nbd_opt_invalid(client, errp,
|
|
"Inconsistent lengths in option %s",
|
|
nbd_opt_lookup(client->opt));
|
|
}
|
|
client->optlen -= size;
|
|
return qio_channel_read_all(client->ioc, buffer, size, errp) < 0 ? -EIO : 1;
|
|
}
|
|
|
|
/* Drop size bytes from the unparsed payload of the current option.
|
|
* Return -errno on I/O error, 0 if option was completely handled by
|
|
* sending a reply about inconsistent lengths, or 1 on success. */
|
|
static int nbd_opt_skip(NBDClient *client, size_t size, Error **errp)
|
|
{
|
|
if (size > client->optlen) {
|
|
return nbd_opt_invalid(client, errp,
|
|
"Inconsistent lengths in option %s",
|
|
nbd_opt_lookup(client->opt));
|
|
}
|
|
client->optlen -= size;
|
|
return nbd_drop(client->ioc, size, errp) < 0 ? -EIO : 1;
|
|
}
|
|
|
|
/* nbd_opt_read_name
|
|
*
|
|
* Read a string with the format:
|
|
* uint32_t len (<= NBD_MAX_NAME_SIZE)
|
|
* len bytes string (not 0-terminated)
|
|
*
|
|
* @name should be enough to store NBD_MAX_NAME_SIZE+1.
|
|
* If @length is non-null, it will be set to the actual string length.
|
|
*
|
|
* Return -errno on I/O error, 0 if option was completely handled by
|
|
* sending a reply about inconsistent lengths, or 1 on success.
|
|
*/
|
|
static int nbd_opt_read_name(NBDClient *client, char *name, uint32_t *length,
|
|
Error **errp)
|
|
{
|
|
int ret;
|
|
uint32_t len;
|
|
|
|
ret = nbd_opt_read(client, &len, sizeof(len), errp);
|
|
if (ret <= 0) {
|
|
return ret;
|
|
}
|
|
len = cpu_to_be32(len);
|
|
|
|
if (len > NBD_MAX_NAME_SIZE) {
|
|
return nbd_opt_invalid(client, errp,
|
|
"Invalid name length: %" PRIu32, len);
|
|
}
|
|
|
|
ret = nbd_opt_read(client, name, len, errp);
|
|
if (ret <= 0) {
|
|
return ret;
|
|
}
|
|
name[len] = '\0';
|
|
|
|
if (length) {
|
|
*length = len;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
/* Send a single NBD_REP_SERVER reply to NBD_OPT_LIST, including payload.
|
|
* Return -errno on error, 0 on success. */
|
|
static int nbd_negotiate_send_rep_list(NBDClient *client, NBDExport *exp,
|
|
Error **errp)
|
|
{
|
|
size_t name_len, desc_len;
|
|
uint32_t len;
|
|
const char *name = exp->name ? exp->name : "";
|
|
const char *desc = exp->description ? exp->description : "";
|
|
QIOChannel *ioc = client->ioc;
|
|
int ret;
|
|
|
|
trace_nbd_negotiate_send_rep_list(name, desc);
|
|
name_len = strlen(name);
|
|
desc_len = strlen(desc);
|
|
len = name_len + desc_len + sizeof(len);
|
|
ret = nbd_negotiate_send_rep_len(client, NBD_REP_SERVER, len, errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
len = cpu_to_be32(name_len);
|
|
if (nbd_write(ioc, &len, sizeof(len), errp) < 0) {
|
|
error_prepend(errp, "write failed (name length): ");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (nbd_write(ioc, name, name_len, errp) < 0) {
|
|
error_prepend(errp, "write failed (name buffer): ");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (nbd_write(ioc, desc, desc_len, errp) < 0) {
|
|
error_prepend(errp, "write failed (description buffer): ");
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Process the NBD_OPT_LIST command, with a potential series of replies.
|
|
* Return -errno on error, 0 on success. */
|
|
static int nbd_negotiate_handle_list(NBDClient *client, Error **errp)
|
|
{
|
|
NBDExport *exp;
|
|
assert(client->opt == NBD_OPT_LIST);
|
|
|
|
/* For each export, send a NBD_REP_SERVER reply. */
|
|
QTAILQ_FOREACH(exp, &exports, next) {
|
|
if (nbd_negotiate_send_rep_list(client, exp, errp)) {
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
/* Finish with a NBD_REP_ACK. */
|
|
return nbd_negotiate_send_rep(client, NBD_REP_ACK, errp);
|
|
}
|
|
|
|
static void nbd_check_meta_export(NBDClient *client)
|
|
{
|
|
client->export_meta.valid &= client->exp == client->export_meta.exp;
|
|
}
|
|
|
|
/* Send a reply to NBD_OPT_EXPORT_NAME.
|
|
* Return -errno on error, 0 on success. */
|
|
static int nbd_negotiate_handle_export_name(NBDClient *client,
|
|
uint16_t myflags, bool no_zeroes,
|
|
Error **errp)
|
|
{
|
|
char name[NBD_MAX_NAME_SIZE + 1];
|
|
char buf[NBD_REPLY_EXPORT_NAME_SIZE] = "";
|
|
size_t len;
|
|
int ret;
|
|
|
|
/* Client sends:
|
|
[20 .. xx] export name (length bytes)
|
|
Server replies:
|
|
[ 0 .. 7] size
|
|
[ 8 .. 9] export flags
|
|
[10 .. 133] reserved (0) [unless no_zeroes]
|
|
*/
|
|
trace_nbd_negotiate_handle_export_name();
|
|
if (client->optlen >= sizeof(name)) {
|
|
error_setg(errp, "Bad length received");
|
|
return -EINVAL;
|
|
}
|
|
if (nbd_read(client->ioc, name, client->optlen, errp) < 0) {
|
|
error_prepend(errp, "read failed: ");
|
|
return -EIO;
|
|
}
|
|
name[client->optlen] = '\0';
|
|
client->optlen = 0;
|
|
|
|
trace_nbd_negotiate_handle_export_name_request(name);
|
|
|
|
client->exp = nbd_export_find(name);
|
|
if (!client->exp) {
|
|
error_setg(errp, "export not found");
|
|
return -EINVAL;
|
|
}
|
|
|
|
trace_nbd_negotiate_new_style_size_flags(client->exp->size,
|
|
client->exp->nbdflags | myflags);
|
|
stq_be_p(buf, client->exp->size);
|
|
stw_be_p(buf + 8, client->exp->nbdflags | myflags);
|
|
len = no_zeroes ? 10 : sizeof(buf);
|
|
ret = nbd_write(client->ioc, buf, len, errp);
|
|
if (ret < 0) {
|
|
error_prepend(errp, "write failed: ");
|
|
return ret;
|
|
}
|
|
|
|
QTAILQ_INSERT_TAIL(&client->exp->clients, client, next);
|
|
nbd_export_get(client->exp);
|
|
nbd_check_meta_export(client);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Send a single NBD_REP_INFO, with a buffer @buf of @length bytes.
|
|
* The buffer does NOT include the info type prefix.
|
|
* Return -errno on error, 0 if ready to send more. */
|
|
static int nbd_negotiate_send_info(NBDClient *client,
|
|
uint16_t info, uint32_t length, void *buf,
|
|
Error **errp)
|
|
{
|
|
int rc;
|
|
|
|
trace_nbd_negotiate_send_info(info, nbd_info_lookup(info), length);
|
|
rc = nbd_negotiate_send_rep_len(client, NBD_REP_INFO,
|
|
sizeof(info) + length, errp);
|
|
if (rc < 0) {
|
|
return rc;
|
|
}
|
|
info = cpu_to_be16(info);
|
|
if (nbd_write(client->ioc, &info, sizeof(info), errp) < 0) {
|
|
return -EIO;
|
|
}
|
|
if (nbd_write(client->ioc, buf, length, errp) < 0) {
|
|
return -EIO;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* nbd_reject_length: Handle any unexpected payload.
|
|
* @fatal requests that we quit talking to the client, even if we are able
|
|
* to successfully send an error reply.
|
|
* Return:
|
|
* -errno transmission error occurred or @fatal was requested, errp is set
|
|
* 0 error message successfully sent to client, errp is not set
|
|
*/
|
|
static int nbd_reject_length(NBDClient *client, bool fatal, Error **errp)
|
|
{
|
|
int ret;
|
|
|
|
assert(client->optlen);
|
|
ret = nbd_opt_invalid(client, errp, "option '%s' has unexpected length",
|
|
nbd_opt_lookup(client->opt));
|
|
if (fatal && !ret) {
|
|
error_setg(errp, "option '%s' has unexpected length",
|
|
nbd_opt_lookup(client->opt));
|
|
return -EINVAL;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/* Handle NBD_OPT_INFO and NBD_OPT_GO.
|
|
* Return -errno on error, 0 if ready for next option, and 1 to move
|
|
* into transmission phase. */
|
|
static int nbd_negotiate_handle_info(NBDClient *client, uint16_t myflags,
|
|
Error **errp)
|
|
{
|
|
int rc;
|
|
char name[NBD_MAX_NAME_SIZE + 1];
|
|
NBDExport *exp;
|
|
uint16_t requests;
|
|
uint16_t request;
|
|
uint32_t namelen;
|
|
bool sendname = false;
|
|
bool blocksize = false;
|
|
uint32_t sizes[3];
|
|
char buf[sizeof(uint64_t) + sizeof(uint16_t)];
|
|
|
|
/* Client sends:
|
|
4 bytes: L, name length (can be 0)
|
|
L bytes: export name
|
|
2 bytes: N, number of requests (can be 0)
|
|
N * 2 bytes: N requests
|
|
*/
|
|
rc = nbd_opt_read_name(client, name, &namelen, errp);
|
|
if (rc <= 0) {
|
|
return rc;
|
|
}
|
|
trace_nbd_negotiate_handle_export_name_request(name);
|
|
|
|
rc = nbd_opt_read(client, &requests, sizeof(requests), errp);
|
|
if (rc <= 0) {
|
|
return rc;
|
|
}
|
|
requests = be16_to_cpu(requests);
|
|
trace_nbd_negotiate_handle_info_requests(requests);
|
|
while (requests--) {
|
|
rc = nbd_opt_read(client, &request, sizeof(request), errp);
|
|
if (rc <= 0) {
|
|
return rc;
|
|
}
|
|
request = be16_to_cpu(request);
|
|
trace_nbd_negotiate_handle_info_request(request,
|
|
nbd_info_lookup(request));
|
|
/* We care about NBD_INFO_NAME and NBD_INFO_BLOCK_SIZE;
|
|
* everything else is either a request we don't know or
|
|
* something we send regardless of request */
|
|
switch (request) {
|
|
case NBD_INFO_NAME:
|
|
sendname = true;
|
|
break;
|
|
case NBD_INFO_BLOCK_SIZE:
|
|
blocksize = true;
|
|
break;
|
|
}
|
|
}
|
|
if (client->optlen) {
|
|
return nbd_reject_length(client, false, errp);
|
|
}
|
|
|
|
exp = nbd_export_find(name);
|
|
if (!exp) {
|
|
return nbd_negotiate_send_rep_err(client, NBD_REP_ERR_UNKNOWN,
|
|
errp, "export '%s' not present",
|
|
name);
|
|
}
|
|
|
|
/* Don't bother sending NBD_INFO_NAME unless client requested it */
|
|
if (sendname) {
|
|
rc = nbd_negotiate_send_info(client, NBD_INFO_NAME, namelen, name,
|
|
errp);
|
|
if (rc < 0) {
|
|
return rc;
|
|
}
|
|
}
|
|
|
|
/* Send NBD_INFO_DESCRIPTION only if available, regardless of
|
|
* client request */
|
|
if (exp->description) {
|
|
size_t len = strlen(exp->description);
|
|
|
|
rc = nbd_negotiate_send_info(client, NBD_INFO_DESCRIPTION,
|
|
len, exp->description, errp);
|
|
if (rc < 0) {
|
|
return rc;
|
|
}
|
|
}
|
|
|
|
/* Send NBD_INFO_BLOCK_SIZE always, but tweak the minimum size
|
|
* according to whether the client requested it, and according to
|
|
* whether this is OPT_INFO or OPT_GO. */
|
|
/* minimum - 1 for back-compat, or 512 if client is new enough.
|
|
* TODO: consult blk_bs(blk)->bl.request_alignment? */
|
|
sizes[0] =
|
|
(client->opt == NBD_OPT_INFO || blocksize) ? BDRV_SECTOR_SIZE : 1;
|
|
/* preferred - Hard-code to 4096 for now.
|
|
* TODO: is blk_bs(blk)->bl.opt_transfer appropriate? */
|
|
sizes[1] = 4096;
|
|
/* maximum - At most 32M, but smaller as appropriate. */
|
|
sizes[2] = MIN(blk_get_max_transfer(exp->blk), NBD_MAX_BUFFER_SIZE);
|
|
trace_nbd_negotiate_handle_info_block_size(sizes[0], sizes[1], sizes[2]);
|
|
sizes[0] = cpu_to_be32(sizes[0]);
|
|
sizes[1] = cpu_to_be32(sizes[1]);
|
|
sizes[2] = cpu_to_be32(sizes[2]);
|
|
rc = nbd_negotiate_send_info(client, NBD_INFO_BLOCK_SIZE,
|
|
sizeof(sizes), sizes, errp);
|
|
if (rc < 0) {
|
|
return rc;
|
|
}
|
|
|
|
/* Send NBD_INFO_EXPORT always */
|
|
trace_nbd_negotiate_new_style_size_flags(exp->size,
|
|
exp->nbdflags | myflags);
|
|
stq_be_p(buf, exp->size);
|
|
stw_be_p(buf + 8, exp->nbdflags | myflags);
|
|
rc = nbd_negotiate_send_info(client, NBD_INFO_EXPORT,
|
|
sizeof(buf), buf, errp);
|
|
if (rc < 0) {
|
|
return rc;
|
|
}
|
|
|
|
/* If the client is just asking for NBD_OPT_INFO, but forgot to
|
|
* request block sizes, return an error.
|
|
* TODO: consult blk_bs(blk)->request_align, and only error if it
|
|
* is not 1? */
|
|
if (client->opt == NBD_OPT_INFO && !blocksize) {
|
|
return nbd_negotiate_send_rep_err(client,
|
|
NBD_REP_ERR_BLOCK_SIZE_REQD,
|
|
errp,
|
|
"request NBD_INFO_BLOCK_SIZE to "
|
|
"use this export");
|
|
}
|
|
|
|
/* Final reply */
|
|
rc = nbd_negotiate_send_rep(client, NBD_REP_ACK, errp);
|
|
if (rc < 0) {
|
|
return rc;
|
|
}
|
|
|
|
if (client->opt == NBD_OPT_GO) {
|
|
client->exp = exp;
|
|
QTAILQ_INSERT_TAIL(&client->exp->clients, client, next);
|
|
nbd_export_get(client->exp);
|
|
nbd_check_meta_export(client);
|
|
rc = 1;
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
|
|
/* Handle NBD_OPT_STARTTLS. Return NULL to drop connection, or else the
|
|
* new channel for all further (now-encrypted) communication. */
|
|
static QIOChannel *nbd_negotiate_handle_starttls(NBDClient *client,
|
|
Error **errp)
|
|
{
|
|
QIOChannel *ioc;
|
|
QIOChannelTLS *tioc;
|
|
struct NBDTLSHandshakeData data = { 0 };
|
|
|
|
assert(client->opt == NBD_OPT_STARTTLS);
|
|
|
|
trace_nbd_negotiate_handle_starttls();
|
|
ioc = client->ioc;
|
|
|
|
if (nbd_negotiate_send_rep(client, NBD_REP_ACK, errp) < 0) {
|
|
return NULL;
|
|
}
|
|
|
|
tioc = qio_channel_tls_new_server(ioc,
|
|
client->tlscreds,
|
|
client->tlsaclname,
|
|
errp);
|
|
if (!tioc) {
|
|
return NULL;
|
|
}
|
|
|
|
qio_channel_set_name(QIO_CHANNEL(tioc), "nbd-server-tls");
|
|
trace_nbd_negotiate_handle_starttls_handshake();
|
|
data.loop = g_main_loop_new(g_main_context_default(), FALSE);
|
|
qio_channel_tls_handshake(tioc,
|
|
nbd_tls_handshake,
|
|
&data,
|
|
NULL,
|
|
NULL);
|
|
|
|
if (!data.complete) {
|
|
g_main_loop_run(data.loop);
|
|
}
|
|
g_main_loop_unref(data.loop);
|
|
if (data.error) {
|
|
object_unref(OBJECT(tioc));
|
|
error_propagate(errp, data.error);
|
|
return NULL;
|
|
}
|
|
|
|
return QIO_CHANNEL(tioc);
|
|
}
|
|
|
|
/* nbd_negotiate_send_meta_context
|
|
*
|
|
* Send one chunk of reply to NBD_OPT_{LIST,SET}_META_CONTEXT
|
|
*
|
|
* For NBD_OPT_LIST_META_CONTEXT @context_id is ignored, 0 is used instead.
|
|
*/
|
|
static int nbd_negotiate_send_meta_context(NBDClient *client,
|
|
const char *context,
|
|
uint32_t context_id,
|
|
Error **errp)
|
|
{
|
|
NBDOptionReplyMetaContext opt;
|
|
struct iovec iov[] = {
|
|
{.iov_base = &opt, .iov_len = sizeof(opt)},
|
|
{.iov_base = (void *)context, .iov_len = strlen(context)}
|
|
};
|
|
|
|
if (client->opt == NBD_OPT_LIST_META_CONTEXT) {
|
|
context_id = 0;
|
|
}
|
|
|
|
trace_nbd_negotiate_meta_query_reply(context, context_id);
|
|
set_be_option_rep(&opt.h, client->opt, NBD_REP_META_CONTEXT,
|
|
sizeof(opt) - sizeof(opt.h) + iov[1].iov_len);
|
|
stl_be_p(&opt.context_id, context_id);
|
|
|
|
return qio_channel_writev_all(client->ioc, iov, 2, errp) < 0 ? -EIO : 0;
|
|
}
|
|
|
|
/* Read strlen(@pattern) bytes, and set @match to true if they match @pattern.
|
|
* @match is never set to false.
|
|
*
|
|
* Return -errno on I/O error, 0 if option was completely handled by
|
|
* sending a reply about inconsistent lengths, or 1 on success.
|
|
*
|
|
* Note: return code = 1 doesn't mean that we've read exactly @pattern.
|
|
* It only means that there are no errors.
|
|
*/
|
|
static int nbd_meta_pattern(NBDClient *client, const char *pattern, bool *match,
|
|
Error **errp)
|
|
{
|
|
int ret;
|
|
char *query;
|
|
size_t len = strlen(pattern);
|
|
|
|
assert(len);
|
|
|
|
query = g_malloc(len);
|
|
ret = nbd_opt_read(client, query, len, errp);
|
|
if (ret <= 0) {
|
|
g_free(query);
|
|
return ret;
|
|
}
|
|
|
|
if (strncmp(query, pattern, len) == 0) {
|
|
trace_nbd_negotiate_meta_query_parse(pattern);
|
|
*match = true;
|
|
} else {
|
|
trace_nbd_negotiate_meta_query_skip("pattern not matched");
|
|
}
|
|
g_free(query);
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Read @len bytes, and set @match to true if they match @pattern, or if @len
|
|
* is 0 and the client is performing _LIST_. @match is never set to false.
|
|
*
|
|
* Return -errno on I/O error, 0 if option was completely handled by
|
|
* sending a reply about inconsistent lengths, or 1 on success.
|
|
*
|
|
* Note: return code = 1 doesn't mean that we've read exactly @pattern.
|
|
* It only means that there are no errors.
|
|
*/
|
|
static int nbd_meta_empty_or_pattern(NBDClient *client, const char *pattern,
|
|
uint32_t len, bool *match, Error **errp)
|
|
{
|
|
if (len == 0) {
|
|
if (client->opt == NBD_OPT_LIST_META_CONTEXT) {
|
|
*match = true;
|
|
}
|
|
trace_nbd_negotiate_meta_query_parse("empty");
|
|
return 1;
|
|
}
|
|
|
|
if (len != strlen(pattern)) {
|
|
trace_nbd_negotiate_meta_query_skip("different lengths");
|
|
return nbd_opt_skip(client, len, errp);
|
|
}
|
|
|
|
return nbd_meta_pattern(client, pattern, match, errp);
|
|
}
|
|
|
|
/* nbd_meta_base_query
|
|
*
|
|
* Handle queries to 'base' namespace. For now, only the base:allocation
|
|
* context is available. 'len' is the amount of text remaining to be read from
|
|
* the current name, after the 'base:' portion has been stripped.
|
|
*
|
|
* Return -errno on I/O error, 0 if option was completely handled by
|
|
* sending a reply about inconsistent lengths, or 1 on success.
|
|
*/
|
|
static int nbd_meta_base_query(NBDClient *client, NBDExportMetaContexts *meta,
|
|
uint32_t len, Error **errp)
|
|
{
|
|
return nbd_meta_empty_or_pattern(client, "allocation", len,
|
|
&meta->base_allocation, errp);
|
|
}
|
|
|
|
/* nbd_meta_bitmap_query
|
|
*
|
|
* Handle query to 'qemu:' namespace.
|
|
* @len is the amount of text remaining to be read from the current name, after
|
|
* the 'qemu:' portion has been stripped.
|
|
*
|
|
* Return -errno on I/O error, 0 if option was completely handled by
|
|
* sending a reply about inconsistent lengths, or 1 on success. */
|
|
static int nbd_meta_qemu_query(NBDClient *client, NBDExportMetaContexts *meta,
|
|
uint32_t len, Error **errp)
|
|
{
|
|
bool dirty_bitmap = false;
|
|
size_t dirty_bitmap_len = strlen("dirty-bitmap:");
|
|
int ret;
|
|
|
|
if (!meta->exp->export_bitmap) {
|
|
trace_nbd_negotiate_meta_query_skip("no dirty-bitmap exported");
|
|
return nbd_opt_skip(client, len, errp);
|
|
}
|
|
|
|
if (len == 0) {
|
|
if (client->opt == NBD_OPT_LIST_META_CONTEXT) {
|
|
meta->bitmap = true;
|
|
}
|
|
trace_nbd_negotiate_meta_query_parse("empty");
|
|
return 1;
|
|
}
|
|
|
|
if (len < dirty_bitmap_len) {
|
|
trace_nbd_negotiate_meta_query_skip("not dirty-bitmap:");
|
|
return nbd_opt_skip(client, len, errp);
|
|
}
|
|
|
|
len -= dirty_bitmap_len;
|
|
ret = nbd_meta_pattern(client, "dirty-bitmap:", &dirty_bitmap, errp);
|
|
if (ret <= 0) {
|
|
return ret;
|
|
}
|
|
if (!dirty_bitmap) {
|
|
trace_nbd_negotiate_meta_query_skip("not dirty-bitmap:");
|
|
return nbd_opt_skip(client, len, errp);
|
|
}
|
|
|
|
trace_nbd_negotiate_meta_query_parse("dirty-bitmap:");
|
|
|
|
return nbd_meta_empty_or_pattern(
|
|
client, meta->exp->export_bitmap_context +
|
|
strlen("qemu:dirty_bitmap:"), len, &meta->bitmap, errp);
|
|
}
|
|
|
|
/* nbd_negotiate_meta_query
|
|
*
|
|
* Parse namespace name and call corresponding function to parse body of the
|
|
* query.
|
|
*
|
|
* The only supported namespace now is 'base'.
|
|
*
|
|
* The function aims not wasting time and memory to read long unknown namespace
|
|
* names.
|
|
*
|
|
* Return -errno on I/O error, 0 if option was completely handled by
|
|
* sending a reply about inconsistent lengths, or 1 on success. */
|
|
static int nbd_negotiate_meta_query(NBDClient *client,
|
|
NBDExportMetaContexts *meta, Error **errp)
|
|
{
|
|
/*
|
|
* Both 'qemu' and 'base' namespaces have length = 5 including a
|
|
* colon. If another length namespace is later introduced, this
|
|
* should certainly be refactored.
|
|
*/
|
|
int ret;
|
|
size_t ns_len = 5;
|
|
char ns[5];
|
|
uint32_t len;
|
|
|
|
ret = nbd_opt_read(client, &len, sizeof(len), errp);
|
|
if (ret <= 0) {
|
|
return ret;
|
|
}
|
|
len = cpu_to_be32(len);
|
|
|
|
if (len < ns_len) {
|
|
trace_nbd_negotiate_meta_query_skip("length too short");
|
|
return nbd_opt_skip(client, len, errp);
|
|
}
|
|
|
|
len -= ns_len;
|
|
ret = nbd_opt_read(client, ns, ns_len, errp);
|
|
if (ret <= 0) {
|
|
return ret;
|
|
}
|
|
|
|
if (!strncmp(ns, "base:", ns_len)) {
|
|
trace_nbd_negotiate_meta_query_parse("base:");
|
|
return nbd_meta_base_query(client, meta, len, errp);
|
|
} else if (!strncmp(ns, "qemu:", ns_len)) {
|
|
trace_nbd_negotiate_meta_query_parse("qemu:");
|
|
return nbd_meta_qemu_query(client, meta, len, errp);
|
|
}
|
|
|
|
trace_nbd_negotiate_meta_query_skip("unknown namespace");
|
|
return nbd_opt_skip(client, len, errp);
|
|
}
|
|
|
|
/* nbd_negotiate_meta_queries
|
|
* Handle NBD_OPT_LIST_META_CONTEXT and NBD_OPT_SET_META_CONTEXT
|
|
*
|
|
* Return -errno on I/O error, or 0 if option was completely handled. */
|
|
static int nbd_negotiate_meta_queries(NBDClient *client,
|
|
NBDExportMetaContexts *meta, Error **errp)
|
|
{
|
|
int ret;
|
|
char export_name[NBD_MAX_NAME_SIZE + 1];
|
|
NBDExportMetaContexts local_meta;
|
|
uint32_t nb_queries;
|
|
int i;
|
|
|
|
if (!client->structured_reply) {
|
|
return nbd_opt_invalid(client, errp,
|
|
"request option '%s' when structured reply "
|
|
"is not negotiated",
|
|
nbd_opt_lookup(client->opt));
|
|
}
|
|
|
|
if (client->opt == NBD_OPT_LIST_META_CONTEXT) {
|
|
/* Only change the caller's meta on SET. */
|
|
meta = &local_meta;
|
|
}
|
|
|
|
memset(meta, 0, sizeof(*meta));
|
|
|
|
ret = nbd_opt_read_name(client, export_name, NULL, errp);
|
|
if (ret <= 0) {
|
|
return ret;
|
|
}
|
|
|
|
meta->exp = nbd_export_find(export_name);
|
|
if (meta->exp == NULL) {
|
|
return nbd_opt_drop(client, NBD_REP_ERR_UNKNOWN, errp,
|
|
"export '%s' not present", export_name);
|
|
}
|
|
|
|
ret = nbd_opt_read(client, &nb_queries, sizeof(nb_queries), errp);
|
|
if (ret <= 0) {
|
|
return ret;
|
|
}
|
|
nb_queries = cpu_to_be32(nb_queries);
|
|
trace_nbd_negotiate_meta_context(nbd_opt_lookup(client->opt),
|
|
export_name, nb_queries);
|
|
|
|
if (client->opt == NBD_OPT_LIST_META_CONTEXT && !nb_queries) {
|
|
/* enable all known contexts */
|
|
meta->base_allocation = true;
|
|
meta->bitmap = !!meta->exp->export_bitmap;
|
|
} else {
|
|
for (i = 0; i < nb_queries; ++i) {
|
|
ret = nbd_negotiate_meta_query(client, meta, errp);
|
|
if (ret <= 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (meta->base_allocation) {
|
|
ret = nbd_negotiate_send_meta_context(client, "base:allocation",
|
|
NBD_META_ID_BASE_ALLOCATION,
|
|
errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
if (meta->bitmap) {
|
|
ret = nbd_negotiate_send_meta_context(client,
|
|
meta->exp->export_bitmap_context,
|
|
NBD_META_ID_DIRTY_BITMAP,
|
|
errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
ret = nbd_negotiate_send_rep(client, NBD_REP_ACK, errp);
|
|
if (ret == 0) {
|
|
meta->valid = true;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* nbd_negotiate_options
|
|
* Process all NBD_OPT_* client option commands, during fixed newstyle
|
|
* negotiation.
|
|
* Return:
|
|
* -errno on error, errp is set
|
|
* 0 on successful negotiation, errp is not set
|
|
* 1 if client sent NBD_OPT_ABORT, i.e. on valid disconnect,
|
|
* errp is not set
|
|
*/
|
|
static int nbd_negotiate_options(NBDClient *client, uint16_t myflags,
|
|
Error **errp)
|
|
{
|
|
uint32_t flags;
|
|
bool fixedNewstyle = false;
|
|
bool no_zeroes = false;
|
|
|
|
/* Client sends:
|
|
[ 0 .. 3] client flags
|
|
|
|
Then we loop until NBD_OPT_EXPORT_NAME or NBD_OPT_GO:
|
|
[ 0 .. 7] NBD_OPTS_MAGIC
|
|
[ 8 .. 11] NBD option
|
|
[12 .. 15] Data length
|
|
... Rest of request
|
|
|
|
[ 0 .. 7] NBD_OPTS_MAGIC
|
|
[ 8 .. 11] Second NBD option
|
|
[12 .. 15] Data length
|
|
... Rest of request
|
|
*/
|
|
|
|
if (nbd_read(client->ioc, &flags, sizeof(flags), errp) < 0) {
|
|
error_prepend(errp, "read failed: ");
|
|
return -EIO;
|
|
}
|
|
flags = be32_to_cpu(flags);
|
|
trace_nbd_negotiate_options_flags(flags);
|
|
if (flags & NBD_FLAG_C_FIXED_NEWSTYLE) {
|
|
fixedNewstyle = true;
|
|
flags &= ~NBD_FLAG_C_FIXED_NEWSTYLE;
|
|
}
|
|
if (flags & NBD_FLAG_C_NO_ZEROES) {
|
|
no_zeroes = true;
|
|
flags &= ~NBD_FLAG_C_NO_ZEROES;
|
|
}
|
|
if (flags != 0) {
|
|
error_setg(errp, "Unknown client flags 0x%" PRIx32 " received", flags);
|
|
return -EINVAL;
|
|
}
|
|
|
|
while (1) {
|
|
int ret;
|
|
uint32_t option, length;
|
|
uint64_t magic;
|
|
|
|
if (nbd_read(client->ioc, &magic, sizeof(magic), errp) < 0) {
|
|
error_prepend(errp, "read failed: ");
|
|
return -EINVAL;
|
|
}
|
|
magic = be64_to_cpu(magic);
|
|
trace_nbd_negotiate_options_check_magic(magic);
|
|
if (magic != NBD_OPTS_MAGIC) {
|
|
error_setg(errp, "Bad magic received");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (nbd_read(client->ioc, &option,
|
|
sizeof(option), errp) < 0) {
|
|
error_prepend(errp, "read failed: ");
|
|
return -EINVAL;
|
|
}
|
|
option = be32_to_cpu(option);
|
|
client->opt = option;
|
|
|
|
if (nbd_read(client->ioc, &length, sizeof(length), errp) < 0) {
|
|
error_prepend(errp, "read failed: ");
|
|
return -EINVAL;
|
|
}
|
|
length = be32_to_cpu(length);
|
|
assert(!client->optlen);
|
|
client->optlen = length;
|
|
|
|
if (length > NBD_MAX_BUFFER_SIZE) {
|
|
error_setg(errp, "len (%" PRIu32" ) is larger than max len (%u)",
|
|
length, NBD_MAX_BUFFER_SIZE);
|
|
return -EINVAL;
|
|
}
|
|
|
|
trace_nbd_negotiate_options_check_option(option,
|
|
nbd_opt_lookup(option));
|
|
if (client->tlscreds &&
|
|
client->ioc == (QIOChannel *)client->sioc) {
|
|
QIOChannel *tioc;
|
|
if (!fixedNewstyle) {
|
|
error_setg(errp, "Unsupported option 0x%" PRIx32, option);
|
|
return -EINVAL;
|
|
}
|
|
switch (option) {
|
|
case NBD_OPT_STARTTLS:
|
|
if (length) {
|
|
/* Unconditionally drop the connection if the client
|
|
* can't start a TLS negotiation correctly */
|
|
return nbd_reject_length(client, true, errp);
|
|
}
|
|
tioc = nbd_negotiate_handle_starttls(client, errp);
|
|
if (!tioc) {
|
|
return -EIO;
|
|
}
|
|
ret = 0;
|
|
object_unref(OBJECT(client->ioc));
|
|
client->ioc = QIO_CHANNEL(tioc);
|
|
break;
|
|
|
|
case NBD_OPT_EXPORT_NAME:
|
|
/* No way to return an error to client, so drop connection */
|
|
error_setg(errp, "Option 0x%x not permitted before TLS",
|
|
option);
|
|
return -EINVAL;
|
|
|
|
default:
|
|
/* Let the client keep trying, unless they asked to
|
|
* quit. Always try to give an error back to the
|
|
* client; but when replying to OPT_ABORT, be aware
|
|
* that the client may hang up before receiving the
|
|
* error, in which case we are fine ignoring the
|
|
* resulting EPIPE. */
|
|
ret = nbd_opt_drop(client, NBD_REP_ERR_TLS_REQD,
|
|
option == NBD_OPT_ABORT ? NULL : errp,
|
|
"Option 0x%" PRIx32
|
|
" not permitted before TLS", option);
|
|
if (option == NBD_OPT_ABORT) {
|
|
return 1;
|
|
}
|
|
break;
|
|
}
|
|
} else if (fixedNewstyle) {
|
|
switch (option) {
|
|
case NBD_OPT_LIST:
|
|
if (length) {
|
|
ret = nbd_reject_length(client, false, errp);
|
|
} else {
|
|
ret = nbd_negotiate_handle_list(client, errp);
|
|
}
|
|
break;
|
|
|
|
case NBD_OPT_ABORT:
|
|
/* NBD spec says we must try to reply before
|
|
* disconnecting, but that we must also tolerate
|
|
* guests that don't wait for our reply. */
|
|
nbd_negotiate_send_rep(client, NBD_REP_ACK, NULL);
|
|
return 1;
|
|
|
|
case NBD_OPT_EXPORT_NAME:
|
|
return nbd_negotiate_handle_export_name(client,
|
|
myflags, no_zeroes,
|
|
errp);
|
|
|
|
case NBD_OPT_INFO:
|
|
case NBD_OPT_GO:
|
|
ret = nbd_negotiate_handle_info(client, myflags, errp);
|
|
if (ret == 1) {
|
|
assert(option == NBD_OPT_GO);
|
|
return 0;
|
|
}
|
|
break;
|
|
|
|
case NBD_OPT_STARTTLS:
|
|
if (length) {
|
|
ret = nbd_reject_length(client, false, errp);
|
|
} else if (client->tlscreds) {
|
|
ret = nbd_negotiate_send_rep_err(client,
|
|
NBD_REP_ERR_INVALID, errp,
|
|
"TLS already enabled");
|
|
} else {
|
|
ret = nbd_negotiate_send_rep_err(client,
|
|
NBD_REP_ERR_POLICY, errp,
|
|
"TLS not configured");
|
|
}
|
|
break;
|
|
|
|
case NBD_OPT_STRUCTURED_REPLY:
|
|
if (length) {
|
|
ret = nbd_reject_length(client, false, errp);
|
|
} else if (client->structured_reply) {
|
|
ret = nbd_negotiate_send_rep_err(
|
|
client, NBD_REP_ERR_INVALID, errp,
|
|
"structured reply already negotiated");
|
|
} else {
|
|
ret = nbd_negotiate_send_rep(client, NBD_REP_ACK, errp);
|
|
client->structured_reply = true;
|
|
myflags |= NBD_FLAG_SEND_DF;
|
|
}
|
|
break;
|
|
|
|
case NBD_OPT_LIST_META_CONTEXT:
|
|
case NBD_OPT_SET_META_CONTEXT:
|
|
ret = nbd_negotiate_meta_queries(client, &client->export_meta,
|
|
errp);
|
|
break;
|
|
|
|
default:
|
|
ret = nbd_opt_drop(client, NBD_REP_ERR_UNSUP, errp,
|
|
"Unsupported option %" PRIu32 " (%s)",
|
|
option, nbd_opt_lookup(option));
|
|
break;
|
|
}
|
|
} else {
|
|
/*
|
|
* If broken new-style we should drop the connection
|
|
* for anything except NBD_OPT_EXPORT_NAME
|
|
*/
|
|
switch (option) {
|
|
case NBD_OPT_EXPORT_NAME:
|
|
return nbd_negotiate_handle_export_name(client,
|
|
myflags, no_zeroes,
|
|
errp);
|
|
|
|
default:
|
|
error_setg(errp, "Unsupported option %" PRIu32 " (%s)",
|
|
option, nbd_opt_lookup(option));
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* nbd_negotiate
|
|
* Return:
|
|
* -errno on error, errp is set
|
|
* 0 on successful negotiation, errp is not set
|
|
* 1 if client sent NBD_OPT_ABORT, i.e. on valid disconnect,
|
|
* errp is not set
|
|
*/
|
|
static coroutine_fn int nbd_negotiate(NBDClient *client, Error **errp)
|
|
{
|
|
char buf[NBD_OLDSTYLE_NEGOTIATE_SIZE] = "";
|
|
int ret;
|
|
const uint16_t myflags = (NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_TRIM |
|
|
NBD_FLAG_SEND_FLUSH | NBD_FLAG_SEND_FUA |
|
|
NBD_FLAG_SEND_WRITE_ZEROES | NBD_FLAG_SEND_CACHE);
|
|
|
|
/* Old style negotiation header, no room for options
|
|
[ 0 .. 7] passwd ("NBDMAGIC")
|
|
[ 8 .. 15] magic (NBD_CLIENT_MAGIC)
|
|
[16 .. 23] size
|
|
[24 .. 27] export flags (zero-extended)
|
|
[28 .. 151] reserved (0)
|
|
|
|
New style negotiation header, client can send options
|
|
[ 0 .. 7] passwd ("NBDMAGIC")
|
|
[ 8 .. 15] magic (NBD_OPTS_MAGIC)
|
|
[16 .. 17] server flags (0)
|
|
....options sent, ending in NBD_OPT_EXPORT_NAME or NBD_OPT_GO....
|
|
*/
|
|
|
|
qio_channel_set_blocking(client->ioc, false, NULL);
|
|
|
|
trace_nbd_negotiate_begin();
|
|
memcpy(buf, "NBDMAGIC", 8);
|
|
|
|
stq_be_p(buf + 8, NBD_OPTS_MAGIC);
|
|
stw_be_p(buf + 16, NBD_FLAG_FIXED_NEWSTYLE | NBD_FLAG_NO_ZEROES);
|
|
|
|
if (nbd_write(client->ioc, buf, 18, errp) < 0) {
|
|
error_prepend(errp, "write failed: ");
|
|
return -EINVAL;
|
|
}
|
|
ret = nbd_negotiate_options(client, myflags, errp);
|
|
if (ret != 0) {
|
|
if (ret < 0) {
|
|
error_prepend(errp, "option negotiation failed: ");
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
assert(!client->optlen);
|
|
trace_nbd_negotiate_success();
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int nbd_receive_request(QIOChannel *ioc, NBDRequest *request,
|
|
Error **errp)
|
|
{
|
|
uint8_t buf[NBD_REQUEST_SIZE];
|
|
uint32_t magic;
|
|
int ret;
|
|
|
|
ret = nbd_read(ioc, buf, sizeof(buf), errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
/* Request
|
|
[ 0 .. 3] magic (NBD_REQUEST_MAGIC)
|
|
[ 4 .. 5] flags (NBD_CMD_FLAG_FUA, ...)
|
|
[ 6 .. 7] type (NBD_CMD_READ, ...)
|
|
[ 8 .. 15] handle
|
|
[16 .. 23] from
|
|
[24 .. 27] len
|
|
*/
|
|
|
|
magic = ldl_be_p(buf);
|
|
request->flags = lduw_be_p(buf + 4);
|
|
request->type = lduw_be_p(buf + 6);
|
|
request->handle = ldq_be_p(buf + 8);
|
|
request->from = ldq_be_p(buf + 16);
|
|
request->len = ldl_be_p(buf + 24);
|
|
|
|
trace_nbd_receive_request(magic, request->flags, request->type,
|
|
request->from, request->len);
|
|
|
|
if (magic != NBD_REQUEST_MAGIC) {
|
|
error_setg(errp, "invalid magic (got 0x%" PRIx32 ")", magic);
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#define MAX_NBD_REQUESTS 16
|
|
|
|
void nbd_client_get(NBDClient *client)
|
|
{
|
|
client->refcount++;
|
|
}
|
|
|
|
void nbd_client_put(NBDClient *client)
|
|
{
|
|
if (--client->refcount == 0) {
|
|
/* The last reference should be dropped by client->close,
|
|
* which is called by client_close.
|
|
*/
|
|
assert(client->closing);
|
|
|
|
qio_channel_detach_aio_context(client->ioc);
|
|
object_unref(OBJECT(client->sioc));
|
|
object_unref(OBJECT(client->ioc));
|
|
if (client->tlscreds) {
|
|
object_unref(OBJECT(client->tlscreds));
|
|
}
|
|
g_free(client->tlsaclname);
|
|
if (client->exp) {
|
|
QTAILQ_REMOVE(&client->exp->clients, client, next);
|
|
nbd_export_put(client->exp);
|
|
}
|
|
g_free(client);
|
|
}
|
|
}
|
|
|
|
static void client_close(NBDClient *client, bool negotiated)
|
|
{
|
|
if (client->closing) {
|
|
return;
|
|
}
|
|
|
|
client->closing = true;
|
|
|
|
/* Force requests to finish. They will drop their own references,
|
|
* then we'll close the socket and free the NBDClient.
|
|
*/
|
|
qio_channel_shutdown(client->ioc, QIO_CHANNEL_SHUTDOWN_BOTH,
|
|
NULL);
|
|
|
|
/* Also tell the client, so that they release their reference. */
|
|
if (client->close_fn) {
|
|
client->close_fn(client, negotiated);
|
|
}
|
|
}
|
|
|
|
static NBDRequestData *nbd_request_get(NBDClient *client)
|
|
{
|
|
NBDRequestData *req;
|
|
|
|
assert(client->nb_requests <= MAX_NBD_REQUESTS - 1);
|
|
client->nb_requests++;
|
|
|
|
req = g_new0(NBDRequestData, 1);
|
|
nbd_client_get(client);
|
|
req->client = client;
|
|
return req;
|
|
}
|
|
|
|
static void nbd_request_put(NBDRequestData *req)
|
|
{
|
|
NBDClient *client = req->client;
|
|
|
|
if (req->data) {
|
|
qemu_vfree(req->data);
|
|
}
|
|
g_free(req);
|
|
|
|
client->nb_requests--;
|
|
nbd_client_receive_next_request(client);
|
|
|
|
nbd_client_put(client);
|
|
}
|
|
|
|
static void blk_aio_attached(AioContext *ctx, void *opaque)
|
|
{
|
|
NBDExport *exp = opaque;
|
|
NBDClient *client;
|
|
|
|
trace_nbd_blk_aio_attached(exp->name, ctx);
|
|
|
|
exp->ctx = ctx;
|
|
|
|
QTAILQ_FOREACH(client, &exp->clients, next) {
|
|
qio_channel_attach_aio_context(client->ioc, ctx);
|
|
if (client->recv_coroutine) {
|
|
aio_co_schedule(ctx, client->recv_coroutine);
|
|
}
|
|
if (client->send_coroutine) {
|
|
aio_co_schedule(ctx, client->send_coroutine);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void blk_aio_detach(void *opaque)
|
|
{
|
|
NBDExport *exp = opaque;
|
|
NBDClient *client;
|
|
|
|
trace_nbd_blk_aio_detach(exp->name, exp->ctx);
|
|
|
|
QTAILQ_FOREACH(client, &exp->clients, next) {
|
|
qio_channel_detach_aio_context(client->ioc);
|
|
}
|
|
|
|
exp->ctx = NULL;
|
|
}
|
|
|
|
static void nbd_eject_notifier(Notifier *n, void *data)
|
|
{
|
|
NBDExport *exp = container_of(n, NBDExport, eject_notifier);
|
|
nbd_export_close(exp);
|
|
}
|
|
|
|
NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
|
|
uint16_t nbdflags, void (*close)(NBDExport *),
|
|
bool writethrough, BlockBackend *on_eject_blk,
|
|
Error **errp)
|
|
{
|
|
AioContext *ctx;
|
|
BlockBackend *blk;
|
|
NBDExport *exp = g_new0(NBDExport, 1);
|
|
uint64_t perm;
|
|
int ret;
|
|
|
|
/*
|
|
* NBD exports are used for non-shared storage migration. Make sure
|
|
* that BDRV_O_INACTIVE is cleared and the image is ready for write
|
|
* access since the export could be available before migration handover.
|
|
*/
|
|
ctx = bdrv_get_aio_context(bs);
|
|
aio_context_acquire(ctx);
|
|
bdrv_invalidate_cache(bs, NULL);
|
|
aio_context_release(ctx);
|
|
|
|
/* Don't allow resize while the NBD server is running, otherwise we don't
|
|
* care what happens with the node. */
|
|
perm = BLK_PERM_CONSISTENT_READ;
|
|
if ((nbdflags & NBD_FLAG_READ_ONLY) == 0) {
|
|
perm |= BLK_PERM_WRITE;
|
|
}
|
|
blk = blk_new(perm, BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED |
|
|
BLK_PERM_WRITE | BLK_PERM_GRAPH_MOD);
|
|
ret = blk_insert_bs(blk, bs, errp);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
blk_set_enable_write_cache(blk, !writethrough);
|
|
|
|
exp->refcount = 1;
|
|
QTAILQ_INIT(&exp->clients);
|
|
exp->blk = blk;
|
|
exp->dev_offset = dev_offset;
|
|
exp->nbdflags = nbdflags;
|
|
exp->size = size < 0 ? blk_getlength(blk) : size;
|
|
if (exp->size < 0) {
|
|
error_setg_errno(errp, -exp->size,
|
|
"Failed to determine the NBD export's length");
|
|
goto fail;
|
|
}
|
|
exp->size -= exp->size % BDRV_SECTOR_SIZE;
|
|
|
|
exp->close = close;
|
|
exp->ctx = blk_get_aio_context(blk);
|
|
blk_add_aio_context_notifier(blk, blk_aio_attached, blk_aio_detach, exp);
|
|
|
|
if (on_eject_blk) {
|
|
blk_ref(on_eject_blk);
|
|
exp->eject_notifier_blk = on_eject_blk;
|
|
exp->eject_notifier.notify = nbd_eject_notifier;
|
|
blk_add_remove_bs_notifier(on_eject_blk, &exp->eject_notifier);
|
|
}
|
|
return exp;
|
|
|
|
fail:
|
|
blk_unref(blk);
|
|
g_free(exp);
|
|
return NULL;
|
|
}
|
|
|
|
NBDExport *nbd_export_find(const char *name)
|
|
{
|
|
NBDExport *exp;
|
|
QTAILQ_FOREACH(exp, &exports, next) {
|
|
if (strcmp(name, exp->name) == 0) {
|
|
return exp;
|
|
}
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
void nbd_export_set_name(NBDExport *exp, const char *name)
|
|
{
|
|
if (exp->name == name) {
|
|
return;
|
|
}
|
|
|
|
nbd_export_get(exp);
|
|
if (exp->name != NULL) {
|
|
g_free(exp->name);
|
|
exp->name = NULL;
|
|
QTAILQ_REMOVE(&exports, exp, next);
|
|
nbd_export_put(exp);
|
|
}
|
|
if (name != NULL) {
|
|
nbd_export_get(exp);
|
|
exp->name = g_strdup(name);
|
|
QTAILQ_INSERT_TAIL(&exports, exp, next);
|
|
}
|
|
nbd_export_put(exp);
|
|
}
|
|
|
|
void nbd_export_set_description(NBDExport *exp, const char *description)
|
|
{
|
|
g_free(exp->description);
|
|
exp->description = g_strdup(description);
|
|
}
|
|
|
|
void nbd_export_close(NBDExport *exp)
|
|
{
|
|
NBDClient *client, *next;
|
|
|
|
nbd_export_get(exp);
|
|
QTAILQ_FOREACH_SAFE(client, &exp->clients, next, next) {
|
|
client_close(client, true);
|
|
}
|
|
nbd_export_set_name(exp, NULL);
|
|
nbd_export_set_description(exp, NULL);
|
|
nbd_export_put(exp);
|
|
}
|
|
|
|
void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp)
|
|
{
|
|
if (mode == NBD_SERVER_REMOVE_MODE_HARD || QTAILQ_EMPTY(&exp->clients)) {
|
|
nbd_export_close(exp);
|
|
return;
|
|
}
|
|
|
|
assert(mode == NBD_SERVER_REMOVE_MODE_SAFE);
|
|
|
|
error_setg(errp, "export '%s' still in use", exp->name);
|
|
error_append_hint(errp, "Use mode='hard' to force client disconnect\n");
|
|
}
|
|
|
|
void nbd_export_get(NBDExport *exp)
|
|
{
|
|
assert(exp->refcount > 0);
|
|
exp->refcount++;
|
|
}
|
|
|
|
void nbd_export_put(NBDExport *exp)
|
|
{
|
|
assert(exp->refcount > 0);
|
|
if (exp->refcount == 1) {
|
|
nbd_export_close(exp);
|
|
}
|
|
|
|
/* nbd_export_close() may theoretically reduce refcount to 0. It may happen
|
|
* if someone calls nbd_export_put() on named export not through
|
|
* nbd_export_set_name() when refcount is 1. So, let's assert that
|
|
* it is > 0.
|
|
*/
|
|
assert(exp->refcount > 0);
|
|
if (--exp->refcount == 0) {
|
|
assert(exp->name == NULL);
|
|
assert(exp->description == NULL);
|
|
|
|
if (exp->close) {
|
|
exp->close(exp);
|
|
}
|
|
|
|
if (exp->blk) {
|
|
if (exp->eject_notifier_blk) {
|
|
notifier_remove(&exp->eject_notifier);
|
|
blk_unref(exp->eject_notifier_blk);
|
|
}
|
|
blk_remove_aio_context_notifier(exp->blk, blk_aio_attached,
|
|
blk_aio_detach, exp);
|
|
blk_unref(exp->blk);
|
|
exp->blk = NULL;
|
|
}
|
|
|
|
if (exp->export_bitmap) {
|
|
bdrv_dirty_bitmap_set_qmp_locked(exp->export_bitmap, false);
|
|
g_free(exp->export_bitmap_context);
|
|
}
|
|
|
|
g_free(exp);
|
|
}
|
|
}
|
|
|
|
BlockBackend *nbd_export_get_blockdev(NBDExport *exp)
|
|
{
|
|
return exp->blk;
|
|
}
|
|
|
|
void nbd_export_close_all(void)
|
|
{
|
|
NBDExport *exp, *next;
|
|
|
|
QTAILQ_FOREACH_SAFE(exp, &exports, next, next) {
|
|
nbd_export_close(exp);
|
|
}
|
|
}
|
|
|
|
static int coroutine_fn nbd_co_send_iov(NBDClient *client, struct iovec *iov,
|
|
unsigned niov, Error **errp)
|
|
{
|
|
int ret;
|
|
|
|
g_assert(qemu_in_coroutine());
|
|
qemu_co_mutex_lock(&client->send_lock);
|
|
client->send_coroutine = qemu_coroutine_self();
|
|
|
|
ret = qio_channel_writev_all(client->ioc, iov, niov, errp) < 0 ? -EIO : 0;
|
|
|
|
client->send_coroutine = NULL;
|
|
qemu_co_mutex_unlock(&client->send_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static inline void set_be_simple_reply(NBDSimpleReply *reply, uint64_t error,
|
|
uint64_t handle)
|
|
{
|
|
stl_be_p(&reply->magic, NBD_SIMPLE_REPLY_MAGIC);
|
|
stl_be_p(&reply->error, error);
|
|
stq_be_p(&reply->handle, handle);
|
|
}
|
|
|
|
static int nbd_co_send_simple_reply(NBDClient *client,
|
|
uint64_t handle,
|
|
uint32_t error,
|
|
void *data,
|
|
size_t len,
|
|
Error **errp)
|
|
{
|
|
NBDSimpleReply reply;
|
|
int nbd_err = system_errno_to_nbd_errno(error);
|
|
struct iovec iov[] = {
|
|
{.iov_base = &reply, .iov_len = sizeof(reply)},
|
|
{.iov_base = data, .iov_len = len}
|
|
};
|
|
|
|
trace_nbd_co_send_simple_reply(handle, nbd_err, nbd_err_lookup(nbd_err),
|
|
len);
|
|
set_be_simple_reply(&reply, nbd_err, handle);
|
|
|
|
return nbd_co_send_iov(client, iov, len ? 2 : 1, errp);
|
|
}
|
|
|
|
static inline void set_be_chunk(NBDStructuredReplyChunk *chunk, uint16_t flags,
|
|
uint16_t type, uint64_t handle, uint32_t length)
|
|
{
|
|
stl_be_p(&chunk->magic, NBD_STRUCTURED_REPLY_MAGIC);
|
|
stw_be_p(&chunk->flags, flags);
|
|
stw_be_p(&chunk->type, type);
|
|
stq_be_p(&chunk->handle, handle);
|
|
stl_be_p(&chunk->length, length);
|
|
}
|
|
|
|
static int coroutine_fn nbd_co_send_structured_done(NBDClient *client,
|
|
uint64_t handle,
|
|
Error **errp)
|
|
{
|
|
NBDStructuredReplyChunk chunk;
|
|
struct iovec iov[] = {
|
|
{.iov_base = &chunk, .iov_len = sizeof(chunk)},
|
|
};
|
|
|
|
trace_nbd_co_send_structured_done(handle);
|
|
set_be_chunk(&chunk, NBD_REPLY_FLAG_DONE, NBD_REPLY_TYPE_NONE, handle, 0);
|
|
|
|
return nbd_co_send_iov(client, iov, 1, errp);
|
|
}
|
|
|
|
static int coroutine_fn nbd_co_send_structured_read(NBDClient *client,
|
|
uint64_t handle,
|
|
uint64_t offset,
|
|
void *data,
|
|
size_t size,
|
|
bool final,
|
|
Error **errp)
|
|
{
|
|
NBDStructuredReadData chunk;
|
|
struct iovec iov[] = {
|
|
{.iov_base = &chunk, .iov_len = sizeof(chunk)},
|
|
{.iov_base = data, .iov_len = size}
|
|
};
|
|
|
|
assert(size);
|
|
trace_nbd_co_send_structured_read(handle, offset, data, size);
|
|
set_be_chunk(&chunk.h, final ? NBD_REPLY_FLAG_DONE : 0,
|
|
NBD_REPLY_TYPE_OFFSET_DATA, handle,
|
|
sizeof(chunk) - sizeof(chunk.h) + size);
|
|
stq_be_p(&chunk.offset, offset);
|
|
|
|
return nbd_co_send_iov(client, iov, 2, errp);
|
|
}
|
|
|
|
static int coroutine_fn nbd_co_send_structured_error(NBDClient *client,
|
|
uint64_t handle,
|
|
uint32_t error,
|
|
const char *msg,
|
|
Error **errp)
|
|
{
|
|
NBDStructuredError chunk;
|
|
int nbd_err = system_errno_to_nbd_errno(error);
|
|
struct iovec iov[] = {
|
|
{.iov_base = &chunk, .iov_len = sizeof(chunk)},
|
|
{.iov_base = (char *)msg, .iov_len = msg ? strlen(msg) : 0},
|
|
};
|
|
|
|
assert(nbd_err);
|
|
trace_nbd_co_send_structured_error(handle, nbd_err,
|
|
nbd_err_lookup(nbd_err), msg ? msg : "");
|
|
set_be_chunk(&chunk.h, NBD_REPLY_FLAG_DONE, NBD_REPLY_TYPE_ERROR, handle,
|
|
sizeof(chunk) - sizeof(chunk.h) + iov[1].iov_len);
|
|
stl_be_p(&chunk.error, nbd_err);
|
|
stw_be_p(&chunk.message_length, iov[1].iov_len);
|
|
|
|
return nbd_co_send_iov(client, iov, 1 + !!iov[1].iov_len, errp);
|
|
}
|
|
|
|
/* Do a sparse read and send the structured reply to the client.
|
|
* Returns -errno if sending fails. bdrv_block_status_above() failure is
|
|
* reported to the client, at which point this function succeeds.
|
|
*/
|
|
static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client,
|
|
uint64_t handle,
|
|
uint64_t offset,
|
|
uint8_t *data,
|
|
size_t size,
|
|
Error **errp)
|
|
{
|
|
int ret = 0;
|
|
NBDExport *exp = client->exp;
|
|
size_t progress = 0;
|
|
|
|
while (progress < size) {
|
|
int64_t pnum;
|
|
int status = bdrv_block_status_above(blk_bs(exp->blk), NULL,
|
|
offset + progress,
|
|
size - progress, &pnum, NULL,
|
|
NULL);
|
|
bool final;
|
|
|
|
if (status < 0) {
|
|
char *msg = g_strdup_printf("unable to check for holes: %s",
|
|
strerror(-status));
|
|
|
|
ret = nbd_co_send_structured_error(client, handle, -status, msg,
|
|
errp);
|
|
g_free(msg);
|
|
return ret;
|
|
}
|
|
assert(pnum && pnum <= size - progress);
|
|
final = progress + pnum == size;
|
|
if (status & BDRV_BLOCK_ZERO) {
|
|
NBDStructuredReadHole chunk;
|
|
struct iovec iov[] = {
|
|
{.iov_base = &chunk, .iov_len = sizeof(chunk)},
|
|
};
|
|
|
|
trace_nbd_co_send_structured_read_hole(handle, offset + progress,
|
|
pnum);
|
|
set_be_chunk(&chunk.h, final ? NBD_REPLY_FLAG_DONE : 0,
|
|
NBD_REPLY_TYPE_OFFSET_HOLE,
|
|
handle, sizeof(chunk) - sizeof(chunk.h));
|
|
stq_be_p(&chunk.offset, offset + progress);
|
|
stl_be_p(&chunk.length, pnum);
|
|
ret = nbd_co_send_iov(client, iov, 1, errp);
|
|
} else {
|
|
ret = blk_pread(exp->blk, offset + progress + exp->dev_offset,
|
|
data + progress, pnum);
|
|
if (ret < 0) {
|
|
error_setg_errno(errp, -ret, "reading from file failed");
|
|
break;
|
|
}
|
|
ret = nbd_co_send_structured_read(client, handle, offset + progress,
|
|
data + progress, pnum, final,
|
|
errp);
|
|
}
|
|
|
|
if (ret < 0) {
|
|
break;
|
|
}
|
|
progress += pnum;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Populate @extents from block status. Update @bytes to be the actual
|
|
* length encoded (which may be smaller than the original), and update
|
|
* @nb_extents to the number of extents used.
|
|
*
|
|
* Returns zero on success and -errno on bdrv_block_status_above failure.
|
|
*/
|
|
static int blockstatus_to_extents(BlockDriverState *bs, uint64_t offset,
|
|
uint64_t *bytes, NBDExtent *extents,
|
|
unsigned int *nb_extents)
|
|
{
|
|
uint64_t remaining_bytes = *bytes;
|
|
NBDExtent *extent = extents, *extents_end = extents + *nb_extents;
|
|
bool first_extent = true;
|
|
|
|
assert(*nb_extents);
|
|
while (remaining_bytes) {
|
|
uint32_t flags;
|
|
int64_t num;
|
|
int ret = bdrv_block_status_above(bs, NULL, offset, remaining_bytes,
|
|
&num, NULL, NULL);
|
|
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
flags = (ret & BDRV_BLOCK_ALLOCATED ? 0 : NBD_STATE_HOLE) |
|
|
(ret & BDRV_BLOCK_ZERO ? NBD_STATE_ZERO : 0);
|
|
offset += num;
|
|
remaining_bytes -= num;
|
|
|
|
if (first_extent) {
|
|
extent->flags = flags;
|
|
extent->length = num;
|
|
first_extent = false;
|
|
continue;
|
|
}
|
|
|
|
if (flags == extent->flags) {
|
|
/* extend current extent */
|
|
extent->length += num;
|
|
} else {
|
|
if (extent + 1 == extents_end) {
|
|
break;
|
|
}
|
|
|
|
/* start new extent */
|
|
extent++;
|
|
extent->flags = flags;
|
|
extent->length = num;
|
|
}
|
|
}
|
|
|
|
extents_end = extent + 1;
|
|
|
|
for (extent = extents; extent < extents_end; extent++) {
|
|
extent->flags = cpu_to_be32(extent->flags);
|
|
extent->length = cpu_to_be32(extent->length);
|
|
}
|
|
|
|
*bytes -= remaining_bytes;
|
|
*nb_extents = extents_end - extents;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* nbd_co_send_extents
|
|
*
|
|
* @length is only for tracing purposes (and may be smaller or larger
|
|
* than the client's original request). @last controls whether
|
|
* NBD_REPLY_FLAG_DONE is sent. @extents should already be in
|
|
* big-endian format.
|
|
*/
|
|
static int nbd_co_send_extents(NBDClient *client, uint64_t handle,
|
|
NBDExtent *extents, unsigned int nb_extents,
|
|
uint64_t length, bool last,
|
|
uint32_t context_id, Error **errp)
|
|
{
|
|
NBDStructuredMeta chunk;
|
|
|
|
struct iovec iov[] = {
|
|
{.iov_base = &chunk, .iov_len = sizeof(chunk)},
|
|
{.iov_base = extents, .iov_len = nb_extents * sizeof(extents[0])}
|
|
};
|
|
|
|
trace_nbd_co_send_extents(handle, nb_extents, context_id, length, last);
|
|
set_be_chunk(&chunk.h, last ? NBD_REPLY_FLAG_DONE : 0,
|
|
NBD_REPLY_TYPE_BLOCK_STATUS,
|
|
handle, sizeof(chunk) - sizeof(chunk.h) + iov[1].iov_len);
|
|
stl_be_p(&chunk.context_id, context_id);
|
|
|
|
return nbd_co_send_iov(client, iov, 2, errp);
|
|
}
|
|
|
|
/* Get block status from the exported device and send it to the client */
|
|
static int nbd_co_send_block_status(NBDClient *client, uint64_t handle,
|
|
BlockDriverState *bs, uint64_t offset,
|
|
uint32_t length, bool dont_fragment,
|
|
bool last, uint32_t context_id,
|
|
Error **errp)
|
|
{
|
|
int ret;
|
|
unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BITMAP_EXTENTS;
|
|
NBDExtent *extents = g_new(NBDExtent, nb_extents);
|
|
uint64_t final_length = length;
|
|
|
|
ret = blockstatus_to_extents(bs, offset, &final_length, extents,
|
|
&nb_extents);
|
|
if (ret < 0) {
|
|
g_free(extents);
|
|
return nbd_co_send_structured_error(
|
|
client, handle, -ret, "can't get block status", errp);
|
|
}
|
|
|
|
ret = nbd_co_send_extents(client, handle, extents, nb_extents,
|
|
final_length, last, context_id, errp);
|
|
|
|
g_free(extents);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Populate @extents from a dirty bitmap. Unless @dont_fragment, the
|
|
* final extent may exceed the original @length. Store in @length the
|
|
* byte length encoded (which may be smaller or larger than the
|
|
* original), and return the number of extents used.
|
|
*/
|
|
static unsigned int bitmap_to_extents(BdrvDirtyBitmap *bitmap, uint64_t offset,
|
|
uint64_t *length, NBDExtent *extents,
|
|
unsigned int nb_extents,
|
|
bool dont_fragment)
|
|
{
|
|
uint64_t begin = offset, end = offset;
|
|
uint64_t overall_end = offset + *length;
|
|
unsigned int i = 0;
|
|
BdrvDirtyBitmapIter *it;
|
|
bool dirty;
|
|
|
|
bdrv_dirty_bitmap_lock(bitmap);
|
|
|
|
it = bdrv_dirty_iter_new(bitmap);
|
|
dirty = bdrv_get_dirty_locked(NULL, bitmap, offset);
|
|
|
|
assert(begin < overall_end && nb_extents);
|
|
while (begin < overall_end && i < nb_extents) {
|
|
bool next_dirty = !dirty;
|
|
|
|
if (dirty) {
|
|
end = bdrv_dirty_bitmap_next_zero(bitmap, begin);
|
|
} else {
|
|
bdrv_set_dirty_iter(it, begin);
|
|
end = bdrv_dirty_iter_next(it);
|
|
}
|
|
if (end == -1 || end - begin > UINT32_MAX) {
|
|
/* Cap to an aligned value < 4G beyond begin. */
|
|
end = MIN(bdrv_dirty_bitmap_size(bitmap),
|
|
begin + UINT32_MAX + 1 -
|
|
bdrv_dirty_bitmap_granularity(bitmap));
|
|
next_dirty = dirty;
|
|
}
|
|
if (dont_fragment && end > overall_end) {
|
|
end = overall_end;
|
|
}
|
|
|
|
extents[i].length = cpu_to_be32(end - begin);
|
|
extents[i].flags = cpu_to_be32(dirty ? NBD_STATE_DIRTY : 0);
|
|
i++;
|
|
begin = end;
|
|
dirty = next_dirty;
|
|
}
|
|
|
|
bdrv_dirty_iter_free(it);
|
|
|
|
bdrv_dirty_bitmap_unlock(bitmap);
|
|
|
|
assert(offset < end);
|
|
*length = end - offset;
|
|
return i;
|
|
}
|
|
|
|
static int nbd_co_send_bitmap(NBDClient *client, uint64_t handle,
|
|
BdrvDirtyBitmap *bitmap, uint64_t offset,
|
|
uint32_t length, bool dont_fragment, bool last,
|
|
uint32_t context_id, Error **errp)
|
|
{
|
|
int ret;
|
|
unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BITMAP_EXTENTS;
|
|
NBDExtent *extents = g_new(NBDExtent, nb_extents);
|
|
uint64_t final_length = length;
|
|
|
|
nb_extents = bitmap_to_extents(bitmap, offset, &final_length, extents,
|
|
nb_extents, dont_fragment);
|
|
|
|
ret = nbd_co_send_extents(client, handle, extents, nb_extents,
|
|
final_length, last, context_id, errp);
|
|
|
|
g_free(extents);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* nbd_co_receive_request
|
|
* Collect a client request. Return 0 if request looks valid, -EIO to drop
|
|
* connection right away, and any other negative value to report an error to
|
|
* the client (although the caller may still need to disconnect after reporting
|
|
* the error).
|
|
*/
|
|
static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request,
|
|
Error **errp)
|
|
{
|
|
NBDClient *client = req->client;
|
|
int valid_flags;
|
|
|
|
g_assert(qemu_in_coroutine());
|
|
assert(client->recv_coroutine == qemu_coroutine_self());
|
|
if (nbd_receive_request(client->ioc, request, errp) < 0) {
|
|
return -EIO;
|
|
}
|
|
|
|
trace_nbd_co_receive_request_decode_type(request->handle, request->type,
|
|
nbd_cmd_lookup(request->type));
|
|
|
|
if (request->type != NBD_CMD_WRITE) {
|
|
/* No payload, we are ready to read the next request. */
|
|
req->complete = true;
|
|
}
|
|
|
|
if (request->type == NBD_CMD_DISC) {
|
|
/* Special case: we're going to disconnect without a reply,
|
|
* whether or not flags, from, or len are bogus */
|
|
return -EIO;
|
|
}
|
|
|
|
if (request->type == NBD_CMD_READ || request->type == NBD_CMD_WRITE ||
|
|
request->type == NBD_CMD_CACHE)
|
|
{
|
|
if (request->len > NBD_MAX_BUFFER_SIZE) {
|
|
error_setg(errp, "len (%" PRIu32" ) is larger than max len (%u)",
|
|
request->len, NBD_MAX_BUFFER_SIZE);
|
|
return -EINVAL;
|
|
}
|
|
|
|
req->data = blk_try_blockalign(client->exp->blk, request->len);
|
|
if (req->data == NULL) {
|
|
error_setg(errp, "No memory");
|
|
return -ENOMEM;
|
|
}
|
|
}
|
|
if (request->type == NBD_CMD_WRITE) {
|
|
if (nbd_read(client->ioc, req->data, request->len, errp) < 0) {
|
|
error_prepend(errp, "reading from socket failed: ");
|
|
return -EIO;
|
|
}
|
|
req->complete = true;
|
|
|
|
trace_nbd_co_receive_request_payload_received(request->handle,
|
|
request->len);
|
|
}
|
|
|
|
/* Sanity checks. */
|
|
if (client->exp->nbdflags & NBD_FLAG_READ_ONLY &&
|
|
(request->type == NBD_CMD_WRITE ||
|
|
request->type == NBD_CMD_WRITE_ZEROES ||
|
|
request->type == NBD_CMD_TRIM)) {
|
|
error_setg(errp, "Export is read-only");
|
|
return -EROFS;
|
|
}
|
|
if (request->from > client->exp->size ||
|
|
request->from + request->len > client->exp->size) {
|
|
error_setg(errp, "operation past EOF; From: %" PRIu64 ", Len: %" PRIu32
|
|
", Size: %" PRIu64, request->from, request->len,
|
|
(uint64_t)client->exp->size);
|
|
return (request->type == NBD_CMD_WRITE ||
|
|
request->type == NBD_CMD_WRITE_ZEROES) ? -ENOSPC : -EINVAL;
|
|
}
|
|
valid_flags = NBD_CMD_FLAG_FUA;
|
|
if (request->type == NBD_CMD_READ && client->structured_reply) {
|
|
valid_flags |= NBD_CMD_FLAG_DF;
|
|
} else if (request->type == NBD_CMD_WRITE_ZEROES) {
|
|
valid_flags |= NBD_CMD_FLAG_NO_HOLE;
|
|
} else if (request->type == NBD_CMD_BLOCK_STATUS) {
|
|
valid_flags |= NBD_CMD_FLAG_REQ_ONE;
|
|
}
|
|
if (request->flags & ~valid_flags) {
|
|
error_setg(errp, "unsupported flags for command %s (got 0x%x)",
|
|
nbd_cmd_lookup(request->type), request->flags);
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Send simple reply without a payload, or a structured error
|
|
* @error_msg is ignored if @ret >= 0
|
|
* Returns 0 if connection is still live, -errno on failure to talk to client
|
|
*/
|
|
static coroutine_fn int nbd_send_generic_reply(NBDClient *client,
|
|
uint64_t handle,
|
|
int ret,
|
|
const char *error_msg,
|
|
Error **errp)
|
|
{
|
|
if (client->structured_reply && ret < 0) {
|
|
return nbd_co_send_structured_error(client, handle, -ret, error_msg,
|
|
errp);
|
|
} else {
|
|
return nbd_co_send_simple_reply(client, handle, ret < 0 ? -ret : 0,
|
|
NULL, 0, errp);
|
|
}
|
|
}
|
|
|
|
/* Handle NBD_CMD_READ request.
|
|
* Return -errno if sending fails. Other errors are reported directly to the
|
|
* client as an error reply. */
|
|
static coroutine_fn int nbd_do_cmd_read(NBDClient *client, NBDRequest *request,
|
|
uint8_t *data, Error **errp)
|
|
{
|
|
int ret;
|
|
NBDExport *exp = client->exp;
|
|
|
|
assert(request->type == NBD_CMD_READ || request->type == NBD_CMD_CACHE);
|
|
|
|
/* XXX: NBD Protocol only documents use of FUA with WRITE */
|
|
if (request->flags & NBD_CMD_FLAG_FUA) {
|
|
ret = blk_co_flush(exp->blk);
|
|
if (ret < 0) {
|
|
return nbd_send_generic_reply(client, request->handle, ret,
|
|
"flush failed", errp);
|
|
}
|
|
}
|
|
|
|
if (client->structured_reply && !(request->flags & NBD_CMD_FLAG_DF) &&
|
|
request->len && request->type != NBD_CMD_CACHE)
|
|
{
|
|
return nbd_co_send_sparse_read(client, request->handle, request->from,
|
|
data, request->len, errp);
|
|
}
|
|
|
|
ret = blk_pread(exp->blk, request->from + exp->dev_offset, data,
|
|
request->len);
|
|
if (ret < 0 || request->type == NBD_CMD_CACHE) {
|
|
return nbd_send_generic_reply(client, request->handle, ret,
|
|
"reading from file failed", errp);
|
|
}
|
|
|
|
if (client->structured_reply) {
|
|
if (request->len) {
|
|
return nbd_co_send_structured_read(client, request->handle,
|
|
request->from, data,
|
|
request->len, true, errp);
|
|
} else {
|
|
return nbd_co_send_structured_done(client, request->handle, errp);
|
|
}
|
|
} else {
|
|
return nbd_co_send_simple_reply(client, request->handle, 0,
|
|
data, request->len, errp);
|
|
}
|
|
}
|
|
|
|
/* Handle NBD request.
|
|
* Return -errno if sending fails. Other errors are reported directly to the
|
|
* client as an error reply. */
|
|
static coroutine_fn int nbd_handle_request(NBDClient *client,
|
|
NBDRequest *request,
|
|
uint8_t *data, Error **errp)
|
|
{
|
|
int ret;
|
|
int flags;
|
|
NBDExport *exp = client->exp;
|
|
char *msg;
|
|
|
|
switch (request->type) {
|
|
case NBD_CMD_READ:
|
|
case NBD_CMD_CACHE:
|
|
return nbd_do_cmd_read(client, request, data, errp);
|
|
|
|
case NBD_CMD_WRITE:
|
|
flags = 0;
|
|
if (request->flags & NBD_CMD_FLAG_FUA) {
|
|
flags |= BDRV_REQ_FUA;
|
|
}
|
|
ret = blk_pwrite(exp->blk, request->from + exp->dev_offset,
|
|
data, request->len, flags);
|
|
return nbd_send_generic_reply(client, request->handle, ret,
|
|
"writing to file failed", errp);
|
|
|
|
case NBD_CMD_WRITE_ZEROES:
|
|
flags = 0;
|
|
if (request->flags & NBD_CMD_FLAG_FUA) {
|
|
flags |= BDRV_REQ_FUA;
|
|
}
|
|
if (!(request->flags & NBD_CMD_FLAG_NO_HOLE)) {
|
|
flags |= BDRV_REQ_MAY_UNMAP;
|
|
}
|
|
ret = blk_pwrite_zeroes(exp->blk, request->from + exp->dev_offset,
|
|
request->len, flags);
|
|
return nbd_send_generic_reply(client, request->handle, ret,
|
|
"writing to file failed", errp);
|
|
|
|
case NBD_CMD_DISC:
|
|
/* unreachable, thanks to special case in nbd_co_receive_request() */
|
|
abort();
|
|
|
|
case NBD_CMD_FLUSH:
|
|
ret = blk_co_flush(exp->blk);
|
|
return nbd_send_generic_reply(client, request->handle, ret,
|
|
"flush failed", errp);
|
|
|
|
case NBD_CMD_TRIM:
|
|
ret = blk_co_pdiscard(exp->blk, request->from + exp->dev_offset,
|
|
request->len);
|
|
if (ret == 0 && request->flags & NBD_CMD_FLAG_FUA) {
|
|
ret = blk_co_flush(exp->blk);
|
|
}
|
|
return nbd_send_generic_reply(client, request->handle, ret,
|
|
"discard failed", errp);
|
|
|
|
case NBD_CMD_BLOCK_STATUS:
|
|
if (!request->len) {
|
|
return nbd_send_generic_reply(client, request->handle, -EINVAL,
|
|
"need non-zero length", errp);
|
|
}
|
|
if (client->export_meta.valid &&
|
|
(client->export_meta.base_allocation ||
|
|
client->export_meta.bitmap))
|
|
{
|
|
bool dont_fragment = request->flags & NBD_CMD_FLAG_REQ_ONE;
|
|
|
|
if (client->export_meta.base_allocation) {
|
|
ret = nbd_co_send_block_status(client, request->handle,
|
|
blk_bs(exp->blk), request->from,
|
|
request->len, dont_fragment,
|
|
!client->export_meta.bitmap,
|
|
NBD_META_ID_BASE_ALLOCATION,
|
|
errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
if (client->export_meta.bitmap) {
|
|
ret = nbd_co_send_bitmap(client, request->handle,
|
|
client->exp->export_bitmap,
|
|
request->from, request->len,
|
|
dont_fragment,
|
|
true, NBD_META_ID_DIRTY_BITMAP, errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
} else {
|
|
return nbd_send_generic_reply(client, request->handle, -EINVAL,
|
|
"CMD_BLOCK_STATUS not negotiated",
|
|
errp);
|
|
}
|
|
|
|
default:
|
|
msg = g_strdup_printf("invalid request type (%" PRIu32 ") received",
|
|
request->type);
|
|
ret = nbd_send_generic_reply(client, request->handle, -EINVAL, msg,
|
|
errp);
|
|
g_free(msg);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
/* Owns a reference to the NBDClient passed as opaque. */
|
|
static coroutine_fn void nbd_trip(void *opaque)
|
|
{
|
|
NBDClient *client = opaque;
|
|
NBDRequestData *req;
|
|
NBDRequest request = { 0 }; /* GCC thinks it can be used uninitialized */
|
|
int ret;
|
|
Error *local_err = NULL;
|
|
|
|
trace_nbd_trip();
|
|
if (client->closing) {
|
|
nbd_client_put(client);
|
|
return;
|
|
}
|
|
|
|
req = nbd_request_get(client);
|
|
ret = nbd_co_receive_request(req, &request, &local_err);
|
|
client->recv_coroutine = NULL;
|
|
|
|
if (client->closing) {
|
|
/*
|
|
* The client may be closed when we are blocked in
|
|
* nbd_co_receive_request()
|
|
*/
|
|
goto done;
|
|
}
|
|
|
|
nbd_client_receive_next_request(client);
|
|
if (ret == -EIO) {
|
|
goto disconnect;
|
|
}
|
|
|
|
if (ret < 0) {
|
|
/* It wans't -EIO, so, according to nbd_co_receive_request()
|
|
* semantics, we should return the error to the client. */
|
|
Error *export_err = local_err;
|
|
|
|
local_err = NULL;
|
|
ret = nbd_send_generic_reply(client, request.handle, -EINVAL,
|
|
error_get_pretty(export_err), &local_err);
|
|
error_free(export_err);
|
|
} else {
|
|
ret = nbd_handle_request(client, &request, req->data, &local_err);
|
|
}
|
|
if (ret < 0) {
|
|
error_prepend(&local_err, "Failed to send reply: ");
|
|
goto disconnect;
|
|
}
|
|
|
|
/* We must disconnect after NBD_CMD_WRITE if we did not
|
|
* read the payload.
|
|
*/
|
|
if (!req->complete) {
|
|
error_setg(&local_err, "Request handling failed in intermediate state");
|
|
goto disconnect;
|
|
}
|
|
|
|
done:
|
|
nbd_request_put(req);
|
|
nbd_client_put(client);
|
|
return;
|
|
|
|
disconnect:
|
|
if (local_err) {
|
|
error_reportf_err(local_err, "Disconnect client, due to: ");
|
|
}
|
|
nbd_request_put(req);
|
|
client_close(client, true);
|
|
nbd_client_put(client);
|
|
}
|
|
|
|
static void nbd_client_receive_next_request(NBDClient *client)
|
|
{
|
|
if (!client->recv_coroutine && client->nb_requests < MAX_NBD_REQUESTS) {
|
|
nbd_client_get(client);
|
|
client->recv_coroutine = qemu_coroutine_create(nbd_trip, client);
|
|
aio_co_schedule(client->exp->ctx, client->recv_coroutine);
|
|
}
|
|
}
|
|
|
|
static coroutine_fn void nbd_co_client_start(void *opaque)
|
|
{
|
|
NBDClient *client = opaque;
|
|
Error *local_err = NULL;
|
|
|
|
qemu_co_mutex_init(&client->send_lock);
|
|
|
|
if (nbd_negotiate(client, &local_err)) {
|
|
if (local_err) {
|
|
error_report_err(local_err);
|
|
}
|
|
client_close(client, false);
|
|
return;
|
|
}
|
|
|
|
nbd_client_receive_next_request(client);
|
|
}
|
|
|
|
/*
|
|
* Create a new client listener using the given channel @sioc.
|
|
* Begin servicing it in a coroutine. When the connection closes, call
|
|
* @close_fn with an indication of whether the client completed negotiation.
|
|
*/
|
|
void nbd_client_new(QIOChannelSocket *sioc,
|
|
QCryptoTLSCreds *tlscreds,
|
|
const char *tlsaclname,
|
|
void (*close_fn)(NBDClient *, bool))
|
|
{
|
|
NBDClient *client;
|
|
Coroutine *co;
|
|
|
|
client = g_new0(NBDClient, 1);
|
|
client->refcount = 1;
|
|
client->tlscreds = tlscreds;
|
|
if (tlscreds) {
|
|
object_ref(OBJECT(client->tlscreds));
|
|
}
|
|
client->tlsaclname = g_strdup(tlsaclname);
|
|
client->sioc = sioc;
|
|
object_ref(OBJECT(client->sioc));
|
|
client->ioc = QIO_CHANNEL(sioc);
|
|
object_ref(OBJECT(client->ioc));
|
|
client->close_fn = close_fn;
|
|
|
|
co = qemu_coroutine_create(nbd_co_client_start, client);
|
|
qemu_coroutine_enter(co);
|
|
}
|
|
|
|
void nbd_export_bitmap(NBDExport *exp, const char *bitmap,
|
|
const char *bitmap_export_name, Error **errp)
|
|
{
|
|
BdrvDirtyBitmap *bm = NULL;
|
|
BlockDriverState *bs = blk_bs(exp->blk);
|
|
|
|
if (exp->export_bitmap) {
|
|
error_setg(errp, "Export bitmap is already set");
|
|
return;
|
|
}
|
|
|
|
while (true) {
|
|
bm = bdrv_find_dirty_bitmap(bs, bitmap);
|
|
if (bm != NULL || bs->backing == NULL) {
|
|
break;
|
|
}
|
|
|
|
bs = bs->backing->bs;
|
|
}
|
|
|
|
if (bm == NULL) {
|
|
error_setg(errp, "Bitmap '%s' is not found", bitmap);
|
|
return;
|
|
}
|
|
|
|
if (bdrv_dirty_bitmap_enabled(bm)) {
|
|
error_setg(errp, "Bitmap '%s' is enabled", bitmap);
|
|
return;
|
|
}
|
|
|
|
if (bdrv_dirty_bitmap_user_locked(bm)) {
|
|
error_setg(errp, "Bitmap '%s' is in use", bitmap);
|
|
return;
|
|
}
|
|
|
|
bdrv_dirty_bitmap_set_qmp_locked(bm, true);
|
|
exp->export_bitmap = bm;
|
|
exp->export_bitmap_context =
|
|
g_strdup_printf("qemu:dirty-bitmap:%s", bitmap_export_name);
|
|
}
|