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2764 lines
86 KiB
C
2764 lines
86 KiB
C
/*
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* Copyright (C) 2016-2022 Red Hat, Inc.
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* Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
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*
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* Network Block Device Server Side
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; under version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see <http://www.gnu.org/licenses/>.
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*/
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#include "qemu/osdep.h"
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#include "block/export.h"
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#include "qapi/error.h"
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#include "qemu/queue.h"
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#include "trace.h"
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#include "nbd-internal.h"
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#include "qemu/units.h"
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#include "qemu/memalign.h"
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#define NBD_META_ID_BASE_ALLOCATION 0
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#define NBD_META_ID_ALLOCATION_DEPTH 1
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/* Dirty bitmaps use 'NBD_META_ID_DIRTY_BITMAP + i', so keep this id last. */
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#define NBD_META_ID_DIRTY_BITMAP 2
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/*
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* NBD_MAX_BLOCK_STATUS_EXTENTS: 1 MiB of extents data. An empirical
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* constant. If an increase is needed, note that the NBD protocol
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* recommends no larger than 32 mb, so that the client won't consider
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* the reply as a denial of service attack.
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*/
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#define NBD_MAX_BLOCK_STATUS_EXTENTS (1 * MiB / 8)
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static int system_errno_to_nbd_errno(int err)
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{
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switch (err) {
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case 0:
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return NBD_SUCCESS;
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case EPERM:
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case EROFS:
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return NBD_EPERM;
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case EIO:
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return NBD_EIO;
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case ENOMEM:
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return NBD_ENOMEM;
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#ifdef EDQUOT
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case EDQUOT:
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#endif
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case EFBIG:
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case ENOSPC:
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return NBD_ENOSPC;
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case EOVERFLOW:
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return NBD_EOVERFLOW;
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case ENOTSUP:
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#if ENOTSUP != EOPNOTSUPP
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case EOPNOTSUPP:
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#endif
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return NBD_ENOTSUP;
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case ESHUTDOWN:
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return NBD_ESHUTDOWN;
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case EINVAL:
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default:
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return NBD_EINVAL;
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}
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}
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/* Definitions for opaque data types */
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typedef struct NBDRequestData NBDRequestData;
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struct NBDRequestData {
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NBDClient *client;
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uint8_t *data;
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bool complete;
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};
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struct NBDExport {
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BlockExport common;
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char *name;
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char *description;
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uint64_t size;
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uint16_t nbdflags;
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QTAILQ_HEAD(, NBDClient) clients;
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QTAILQ_ENTRY(NBDExport) next;
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BlockBackend *eject_notifier_blk;
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Notifier eject_notifier;
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bool allocation_depth;
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BdrvDirtyBitmap **export_bitmaps;
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size_t nr_export_bitmaps;
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};
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static QTAILQ_HEAD(, NBDExport) exports = QTAILQ_HEAD_INITIALIZER(exports);
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/* NBDExportMetaContexts represents a list of contexts to be exported,
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* as selected by NBD_OPT_SET_META_CONTEXT. Also used for
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* NBD_OPT_LIST_META_CONTEXT. */
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typedef struct NBDExportMetaContexts {
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NBDExport *exp;
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size_t count; /* number of negotiated contexts */
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bool base_allocation; /* export base:allocation context (block status) */
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bool allocation_depth; /* export qemu:allocation-depth */
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bool *bitmaps; /*
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* export qemu:dirty-bitmap:<export bitmap name>,
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* sized by exp->nr_export_bitmaps
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*/
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} NBDExportMetaContexts;
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struct NBDClient {
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int refcount;
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void (*close_fn)(NBDClient *client, bool negotiated);
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NBDExport *exp;
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QCryptoTLSCreds *tlscreds;
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char *tlsauthz;
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QIOChannelSocket *sioc; /* The underlying data channel */
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QIOChannel *ioc; /* The current I/O channel which may differ (eg TLS) */
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Coroutine *recv_coroutine;
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CoMutex send_lock;
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Coroutine *send_coroutine;
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bool read_yielding;
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bool quiescing;
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QTAILQ_ENTRY(NBDClient) next;
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int nb_requests;
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bool closing;
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uint32_t check_align; /* If non-zero, check for aligned client requests */
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bool structured_reply;
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NBDExportMetaContexts export_meta;
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uint32_t opt; /* Current option being negotiated */
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uint32_t optlen; /* remaining length of data in ioc for the option being
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negotiated now */
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};
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static void nbd_client_receive_next_request(NBDClient *client);
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/* Basic flow for negotiation
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Server Client
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Negotiate
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or
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Server Client
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Negotiate #1
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Option
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Negotiate #2
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----
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followed by
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Server Client
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Request
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Response
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Request
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Response
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...
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...
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Request (type == 2)
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*/
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static inline void set_be_option_rep(NBDOptionReply *rep, uint32_t option,
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uint32_t type, uint32_t length)
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{
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stq_be_p(&rep->magic, NBD_REP_MAGIC);
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stl_be_p(&rep->option, option);
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stl_be_p(&rep->type, type);
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stl_be_p(&rep->length, length);
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}
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/* Send a reply header, including length, but no payload.
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* Return -errno on error, 0 on success. */
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static int nbd_negotiate_send_rep_len(NBDClient *client, uint32_t type,
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uint32_t len, Error **errp)
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{
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NBDOptionReply rep;
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trace_nbd_negotiate_send_rep_len(client->opt, nbd_opt_lookup(client->opt),
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type, nbd_rep_lookup(type), len);
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assert(len < NBD_MAX_BUFFER_SIZE);
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set_be_option_rep(&rep, client->opt, type, len);
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return nbd_write(client->ioc, &rep, sizeof(rep), errp);
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}
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/* Send a reply header with default 0 length.
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* Return -errno on error, 0 on success. */
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static int nbd_negotiate_send_rep(NBDClient *client, uint32_t type,
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Error **errp)
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{
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return nbd_negotiate_send_rep_len(client, type, 0, errp);
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}
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/* Send an error reply.
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* Return -errno on error, 0 on success. */
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static int G_GNUC_PRINTF(4, 0)
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nbd_negotiate_send_rep_verr(NBDClient *client, uint32_t type,
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Error **errp, const char *fmt, va_list va)
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{
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ERRP_GUARD();
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g_autofree char *msg = NULL;
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int ret;
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size_t len;
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msg = g_strdup_vprintf(fmt, va);
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len = strlen(msg);
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assert(len < NBD_MAX_STRING_SIZE);
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trace_nbd_negotiate_send_rep_err(msg);
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ret = nbd_negotiate_send_rep_len(client, type, len, errp);
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if (ret < 0) {
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return ret;
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}
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if (nbd_write(client->ioc, msg, len, errp) < 0) {
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error_prepend(errp, "write failed (error message): ");
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return -EIO;
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}
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return 0;
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}
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/*
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* Return a malloc'd copy of @name suitable for use in an error reply.
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*/
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static char *
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nbd_sanitize_name(const char *name)
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{
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if (strnlen(name, 80) < 80) {
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return g_strdup(name);
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}
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/* XXX Should we also try to sanitize any control characters? */
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return g_strdup_printf("%.80s...", name);
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}
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/* Send an error reply.
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* Return -errno on error, 0 on success. */
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static int G_GNUC_PRINTF(4, 5)
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nbd_negotiate_send_rep_err(NBDClient *client, uint32_t type,
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Error **errp, const char *fmt, ...)
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{
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va_list va;
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int ret;
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va_start(va, fmt);
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ret = nbd_negotiate_send_rep_verr(client, type, errp, fmt, va);
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va_end(va);
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return ret;
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}
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/* Drop remainder of the current option, and send a reply with the
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* given error type and message. Return -errno on read or write
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* failure; or 0 if connection is still live. */
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static int G_GNUC_PRINTF(4, 0)
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nbd_opt_vdrop(NBDClient *client, uint32_t type, Error **errp,
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const char *fmt, va_list va)
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{
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int ret = nbd_drop(client->ioc, client->optlen, errp);
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client->optlen = 0;
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if (!ret) {
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ret = nbd_negotiate_send_rep_verr(client, type, errp, fmt, va);
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}
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return ret;
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}
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static int G_GNUC_PRINTF(4, 5)
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nbd_opt_drop(NBDClient *client, uint32_t type, Error **errp,
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const char *fmt, ...)
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{
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int ret;
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va_list va;
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va_start(va, fmt);
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ret = nbd_opt_vdrop(client, type, errp, fmt, va);
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va_end(va);
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return ret;
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}
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static int G_GNUC_PRINTF(3, 4)
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nbd_opt_invalid(NBDClient *client, Error **errp, const char *fmt, ...)
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{
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int ret;
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va_list va;
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va_start(va, fmt);
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ret = nbd_opt_vdrop(client, NBD_REP_ERR_INVALID, errp, fmt, va);
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va_end(va);
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return ret;
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}
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/* Read size bytes from the unparsed payload of the current option.
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* If @check_nul, require that no NUL bytes appear in buffer.
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* Return -errno on I/O error, 0 if option was completely handled by
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* sending a reply about inconsistent lengths, or 1 on success. */
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static int nbd_opt_read(NBDClient *client, void *buffer, size_t size,
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bool check_nul, Error **errp)
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{
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if (size > client->optlen) {
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return nbd_opt_invalid(client, errp,
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"Inconsistent lengths in option %s",
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nbd_opt_lookup(client->opt));
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}
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client->optlen -= size;
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if (qio_channel_read_all(client->ioc, buffer, size, errp) < 0) {
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return -EIO;
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}
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if (check_nul && strnlen(buffer, size) != size) {
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return nbd_opt_invalid(client, errp,
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"Unexpected embedded NUL in option %s",
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nbd_opt_lookup(client->opt));
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}
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return 1;
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}
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/* Drop size bytes from the unparsed payload of the current option.
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* Return -errno on I/O error, 0 if option was completely handled by
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* sending a reply about inconsistent lengths, or 1 on success. */
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static int nbd_opt_skip(NBDClient *client, size_t size, Error **errp)
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{
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if (size > client->optlen) {
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return nbd_opt_invalid(client, errp,
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"Inconsistent lengths in option %s",
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nbd_opt_lookup(client->opt));
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}
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client->optlen -= size;
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return nbd_drop(client->ioc, size, errp) < 0 ? -EIO : 1;
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}
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/* nbd_opt_read_name
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*
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* Read a string with the format:
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* uint32_t len (<= NBD_MAX_STRING_SIZE)
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* len bytes string (not 0-terminated)
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*
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* On success, @name will be allocated.
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* If @length is non-null, it will be set to the actual string length.
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*
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* Return -errno on I/O error, 0 if option was completely handled by
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* sending a reply about inconsistent lengths, or 1 on success.
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*/
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static int nbd_opt_read_name(NBDClient *client, char **name, uint32_t *length,
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Error **errp)
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{
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int ret;
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uint32_t len;
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g_autofree char *local_name = NULL;
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*name = NULL;
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ret = nbd_opt_read(client, &len, sizeof(len), false, errp);
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if (ret <= 0) {
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return ret;
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}
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len = cpu_to_be32(len);
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if (len > NBD_MAX_STRING_SIZE) {
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return nbd_opt_invalid(client, errp,
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"Invalid name length: %" PRIu32, len);
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}
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local_name = g_malloc(len + 1);
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ret = nbd_opt_read(client, local_name, len, true, errp);
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if (ret <= 0) {
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return ret;
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}
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local_name[len] = '\0';
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if (length) {
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*length = len;
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}
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*name = g_steal_pointer(&local_name);
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return 1;
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}
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/* Send a single NBD_REP_SERVER reply to NBD_OPT_LIST, including payload.
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* Return -errno on error, 0 on success. */
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static int nbd_negotiate_send_rep_list(NBDClient *client, NBDExport *exp,
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Error **errp)
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{
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ERRP_GUARD();
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size_t name_len, desc_len;
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uint32_t len;
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const char *name = exp->name ? exp->name : "";
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const char *desc = exp->description ? exp->description : "";
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QIOChannel *ioc = client->ioc;
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int ret;
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trace_nbd_negotiate_send_rep_list(name, desc);
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name_len = strlen(name);
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desc_len = strlen(desc);
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assert(name_len <= NBD_MAX_STRING_SIZE && desc_len <= NBD_MAX_STRING_SIZE);
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len = name_len + desc_len + sizeof(len);
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ret = nbd_negotiate_send_rep_len(client, NBD_REP_SERVER, len, errp);
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if (ret < 0) {
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return ret;
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}
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len = cpu_to_be32(name_len);
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if (nbd_write(ioc, &len, sizeof(len), errp) < 0) {
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error_prepend(errp, "write failed (name length): ");
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return -EINVAL;
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}
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if (nbd_write(ioc, name, name_len, errp) < 0) {
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error_prepend(errp, "write failed (name buffer): ");
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return -EINVAL;
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}
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if (nbd_write(ioc, desc, desc_len, errp) < 0) {
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error_prepend(errp, "write failed (description buffer): ");
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return -EINVAL;
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}
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return 0;
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}
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|
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/* Process the NBD_OPT_LIST command, with a potential series of replies.
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* Return -errno on error, 0 on success. */
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static int nbd_negotiate_handle_list(NBDClient *client, Error **errp)
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{
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NBDExport *exp;
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assert(client->opt == NBD_OPT_LIST);
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|
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/* For each export, send a NBD_REP_SERVER reply. */
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QTAILQ_FOREACH(exp, &exports, next) {
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if (nbd_negotiate_send_rep_list(client, exp, errp)) {
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return -EINVAL;
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}
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}
|
|
/* Finish with a NBD_REP_ACK. */
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return nbd_negotiate_send_rep(client, NBD_REP_ACK, errp);
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}
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|
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static void nbd_check_meta_export(NBDClient *client)
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{
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if (client->exp != client->export_meta.exp) {
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client->export_meta.count = 0;
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}
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}
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|
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/* Send a reply to NBD_OPT_EXPORT_NAME.
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* Return -errno on error, 0 on success. */
|
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static int nbd_negotiate_handle_export_name(NBDClient *client, bool no_zeroes,
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Error **errp)
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{
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ERRP_GUARD();
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g_autofree char *name = NULL;
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char buf[NBD_REPLY_EXPORT_NAME_SIZE] = "";
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size_t len;
|
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int ret;
|
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uint16_t myflags;
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|
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/* Client sends:
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[20 .. xx] export name (length bytes)
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|
Server replies:
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[ 0 .. 7] size
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|
[ 8 .. 9] export flags
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[10 .. 133] reserved (0) [unless no_zeroes]
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*/
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|
trace_nbd_negotiate_handle_export_name();
|
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if (client->optlen > NBD_MAX_STRING_SIZE) {
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error_setg(errp, "Bad length received");
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return -EINVAL;
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}
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name = g_malloc(client->optlen + 1);
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if (nbd_read(client->ioc, name, client->optlen, "export name", errp) < 0) {
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return -EIO;
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}
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name[client->optlen] = '\0';
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client->optlen = 0;
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trace_nbd_negotiate_handle_export_name_request(name);
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client->exp = nbd_export_find(name);
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if (!client->exp) {
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error_setg(errp, "export not found");
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return -EINVAL;
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}
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|
|
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myflags = client->exp->nbdflags;
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if (client->structured_reply) {
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myflags |= NBD_FLAG_SEND_DF;
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}
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trace_nbd_negotiate_new_style_size_flags(client->exp->size, myflags);
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stq_be_p(buf, client->exp->size);
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stw_be_p(buf + 8, myflags);
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len = no_zeroes ? 10 : sizeof(buf);
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ret = nbd_write(client->ioc, buf, len, errp);
|
|
if (ret < 0) {
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error_prepend(errp, "write failed: ");
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return ret;
|
|
}
|
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|
|
QTAILQ_INSERT_TAIL(&client->exp->clients, client, next);
|
|
blk_exp_ref(&client->exp->common);
|
|
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, Error **errp)
|
|
{
|
|
int rc;
|
|
g_autofree char *name = NULL;
|
|
NBDExport *exp;
|
|
uint16_t requests;
|
|
uint16_t request;
|
|
uint32_t namelen = 0;
|
|
bool sendname = false;
|
|
bool blocksize = false;
|
|
uint32_t sizes[3];
|
|
char buf[sizeof(uint64_t) + sizeof(uint16_t)];
|
|
uint32_t check_align = 0;
|
|
uint16_t myflags;
|
|
|
|
/* 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), false, 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), false, 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) {
|
|
g_autofree char *sane_name = nbd_sanitize_name(name);
|
|
|
|
return nbd_negotiate_send_rep_err(client, NBD_REP_ERR_UNKNOWN,
|
|
errp, "export '%s' not present",
|
|
sane_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);
|
|
|
|
assert(len <= NBD_MAX_STRING_SIZE);
|
|
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 actual if client will obey it. */
|
|
if (client->opt == NBD_OPT_INFO || blocksize) {
|
|
check_align = sizes[0] = blk_get_request_alignment(exp->common.blk);
|
|
} else {
|
|
sizes[0] = 1;
|
|
}
|
|
assert(sizes[0] <= NBD_MAX_BUFFER_SIZE);
|
|
/* preferred - Hard-code to 4096 for now.
|
|
* TODO: is blk_bs(blk)->bl.opt_transfer appropriate? */
|
|
sizes[1] = MAX(4096, sizes[0]);
|
|
/* maximum - At most 32M, but smaller as appropriate. */
|
|
sizes[2] = MIN(blk_get_max_transfer(exp->common.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 */
|
|
myflags = exp->nbdflags;
|
|
if (client->structured_reply) {
|
|
myflags |= NBD_FLAG_SEND_DF;
|
|
}
|
|
trace_nbd_negotiate_new_style_size_flags(exp->size, myflags);
|
|
stq_be_p(buf, exp->size);
|
|
stw_be_p(buf + 8, 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 in a situation that would impact
|
|
* performance, then return an error. But for NBD_OPT_GO, we
|
|
* tolerate all clients, regardless of alignments.
|
|
*/
|
|
if (client->opt == NBD_OPT_INFO && !blocksize &&
|
|
blk_get_request_alignment(exp->common.blk) > 1) {
|
|
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;
|
|
client->check_align = check_align;
|
|
QTAILQ_INSERT_TAIL(&client->exp->clients, client, next);
|
|
blk_exp_ref(&client->exp->common);
|
|
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->tlsauthz,
|
|
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)}
|
|
};
|
|
|
|
assert(iov[1].iov_len <= NBD_MAX_STRING_SIZE);
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* Return true if @query matches @pattern, or if @query is empty when
|
|
* the @client is performing _LIST_.
|
|
*/
|
|
static bool nbd_meta_empty_or_pattern(NBDClient *client, const char *pattern,
|
|
const char *query)
|
|
{
|
|
if (!*query) {
|
|
trace_nbd_negotiate_meta_query_parse("empty");
|
|
return client->opt == NBD_OPT_LIST_META_CONTEXT;
|
|
}
|
|
if (strcmp(query, pattern) == 0) {
|
|
trace_nbd_negotiate_meta_query_parse(pattern);
|
|
return true;
|
|
}
|
|
trace_nbd_negotiate_meta_query_skip("pattern not matched");
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Return true and adjust @str in place if it begins with @prefix.
|
|
*/
|
|
static bool nbd_strshift(const char **str, const char *prefix)
|
|
{
|
|
size_t len = strlen(prefix);
|
|
|
|
if (strncmp(*str, prefix, len) == 0) {
|
|
*str += len;
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/* nbd_meta_base_query
|
|
*
|
|
* Handle queries to 'base' namespace. For now, only the base:allocation
|
|
* context is available. Return true if @query has been handled.
|
|
*/
|
|
static bool nbd_meta_base_query(NBDClient *client, NBDExportMetaContexts *meta,
|
|
const char *query)
|
|
{
|
|
if (!nbd_strshift(&query, "base:")) {
|
|
return false;
|
|
}
|
|
trace_nbd_negotiate_meta_query_parse("base:");
|
|
|
|
if (nbd_meta_empty_or_pattern(client, "allocation", query)) {
|
|
meta->base_allocation = true;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/* nbd_meta_qemu_query
|
|
*
|
|
* Handle queries to 'qemu' namespace. For now, only the qemu:dirty-bitmap:
|
|
* and qemu:allocation-depth contexts are available. Return true if @query
|
|
* has been handled.
|
|
*/
|
|
static bool nbd_meta_qemu_query(NBDClient *client, NBDExportMetaContexts *meta,
|
|
const char *query)
|
|
{
|
|
size_t i;
|
|
|
|
if (!nbd_strshift(&query, "qemu:")) {
|
|
return false;
|
|
}
|
|
trace_nbd_negotiate_meta_query_parse("qemu:");
|
|
|
|
if (!*query) {
|
|
if (client->opt == NBD_OPT_LIST_META_CONTEXT) {
|
|
meta->allocation_depth = meta->exp->allocation_depth;
|
|
if (meta->exp->nr_export_bitmaps) {
|
|
memset(meta->bitmaps, 1, meta->exp->nr_export_bitmaps);
|
|
}
|
|
}
|
|
trace_nbd_negotiate_meta_query_parse("empty");
|
|
return true;
|
|
}
|
|
|
|
if (strcmp(query, "allocation-depth") == 0) {
|
|
trace_nbd_negotiate_meta_query_parse("allocation-depth");
|
|
meta->allocation_depth = meta->exp->allocation_depth;
|
|
return true;
|
|
}
|
|
|
|
if (nbd_strshift(&query, "dirty-bitmap:")) {
|
|
trace_nbd_negotiate_meta_query_parse("dirty-bitmap:");
|
|
if (!*query) {
|
|
if (client->opt == NBD_OPT_LIST_META_CONTEXT &&
|
|
meta->exp->nr_export_bitmaps) {
|
|
memset(meta->bitmaps, 1, meta->exp->nr_export_bitmaps);
|
|
}
|
|
trace_nbd_negotiate_meta_query_parse("empty");
|
|
return true;
|
|
}
|
|
|
|
for (i = 0; i < meta->exp->nr_export_bitmaps; i++) {
|
|
const char *bm_name;
|
|
|
|
bm_name = bdrv_dirty_bitmap_name(meta->exp->export_bitmaps[i]);
|
|
if (strcmp(bm_name, query) == 0) {
|
|
meta->bitmaps[i] = true;
|
|
trace_nbd_negotiate_meta_query_parse(query);
|
|
return true;
|
|
}
|
|
}
|
|
trace_nbd_negotiate_meta_query_skip("no dirty-bitmap match");
|
|
return true;
|
|
}
|
|
|
|
trace_nbd_negotiate_meta_query_skip("unknown qemu context");
|
|
return true;
|
|
}
|
|
|
|
/* nbd_negotiate_meta_query
|
|
*
|
|
* Parse namespace name and call corresponding function to parse body of the
|
|
* query.
|
|
*
|
|
* The only supported namespaces are 'base' and 'qemu'.
|
|
*
|
|
* 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)
|
|
{
|
|
int ret;
|
|
g_autofree char *query = NULL;
|
|
uint32_t len;
|
|
|
|
ret = nbd_opt_read(client, &len, sizeof(len), false, errp);
|
|
if (ret <= 0) {
|
|
return ret;
|
|
}
|
|
len = cpu_to_be32(len);
|
|
|
|
if (len > NBD_MAX_STRING_SIZE) {
|
|
trace_nbd_negotiate_meta_query_skip("length too long");
|
|
return nbd_opt_skip(client, len, errp);
|
|
}
|
|
|
|
query = g_malloc(len + 1);
|
|
ret = nbd_opt_read(client, query, len, true, errp);
|
|
if (ret <= 0) {
|
|
return ret;
|
|
}
|
|
query[len] = '\0';
|
|
|
|
if (nbd_meta_base_query(client, meta, query)) {
|
|
return 1;
|
|
}
|
|
if (nbd_meta_qemu_query(client, meta, query)) {
|
|
return 1;
|
|
}
|
|
|
|
trace_nbd_negotiate_meta_query_skip("unknown namespace");
|
|
return 1;
|
|
}
|
|
|
|
/* 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;
|
|
g_autofree char *export_name = NULL;
|
|
/* Mark unused to work around https://bugs.llvm.org/show_bug.cgi?id=3888 */
|
|
g_autofree G_GNUC_UNUSED bool *bitmaps = NULL;
|
|
NBDExportMetaContexts local_meta = {0};
|
|
uint32_t nb_queries;
|
|
size_t i;
|
|
size_t count = 0;
|
|
|
|
if (client->opt == NBD_OPT_SET_META_CONTEXT && !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;
|
|
}
|
|
|
|
g_free(meta->bitmaps);
|
|
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) {
|
|
g_autofree char *sane_name = nbd_sanitize_name(export_name);
|
|
|
|
return nbd_opt_drop(client, NBD_REP_ERR_UNKNOWN, errp,
|
|
"export '%s' not present", sane_name);
|
|
}
|
|
meta->bitmaps = g_new0(bool, meta->exp->nr_export_bitmaps);
|
|
if (client->opt == NBD_OPT_LIST_META_CONTEXT) {
|
|
bitmaps = meta->bitmaps;
|
|
}
|
|
|
|
ret = nbd_opt_read(client, &nb_queries, sizeof(nb_queries), false, 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->allocation_depth = meta->exp->allocation_depth;
|
|
if (meta->exp->nr_export_bitmaps) {
|
|
memset(meta->bitmaps, 1, meta->exp->nr_export_bitmaps);
|
|
}
|
|
} 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;
|
|
}
|
|
count++;
|
|
}
|
|
|
|
if (meta->allocation_depth) {
|
|
ret = nbd_negotiate_send_meta_context(client, "qemu:allocation-depth",
|
|
NBD_META_ID_ALLOCATION_DEPTH,
|
|
errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
count++;
|
|
}
|
|
|
|
for (i = 0; i < meta->exp->nr_export_bitmaps; i++) {
|
|
const char *bm_name;
|
|
g_autofree char *context = NULL;
|
|
|
|
if (!meta->bitmaps[i]) {
|
|
continue;
|
|
}
|
|
|
|
bm_name = bdrv_dirty_bitmap_name(meta->exp->export_bitmaps[i]);
|
|
context = g_strdup_printf("qemu:dirty-bitmap:%s", bm_name);
|
|
|
|
ret = nbd_negotiate_send_meta_context(client, context,
|
|
NBD_META_ID_DIRTY_BITMAP + i,
|
|
errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
count++;
|
|
}
|
|
|
|
ret = nbd_negotiate_send_rep(client, NBD_REP_ACK, errp);
|
|
if (ret == 0) {
|
|
meta->count = count;
|
|
}
|
|
|
|
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, 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_read32(client->ioc, &flags, "flags", errp) < 0) {
|
|
return -EIO;
|
|
}
|
|
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_read64(client->ioc, &magic, "opts magic", errp) < 0) {
|
|
return -EINVAL;
|
|
}
|
|
trace_nbd_negotiate_options_check_magic(magic);
|
|
if (magic != NBD_OPTS_MAGIC) {
|
|
error_setg(errp, "Bad magic received");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (nbd_read32(client->ioc, &option, "option", errp) < 0) {
|
|
return -EINVAL;
|
|
}
|
|
client->opt = option;
|
|
|
|
if (nbd_read32(client->ioc, &length, "option length", errp) < 0) {
|
|
return -EINVAL;
|
|
}
|
|
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, no_zeroes,
|
|
errp);
|
|
|
|
case NBD_OPT_INFO:
|
|
case NBD_OPT_GO:
|
|
ret = nbd_negotiate_handle_info(client, 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;
|
|
}
|
|
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, 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)
|
|
{
|
|
ERRP_GUARD();
|
|
char buf[NBD_OLDSTYLE_NEGOTIATE_SIZE] = "";
|
|
int ret;
|
|
|
|
/* 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, errp);
|
|
if (ret != 0) {
|
|
if (ret < 0) {
|
|
error_prepend(errp, "option negotiation failed: ");
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/* Attach the channel to the same AioContext as the export */
|
|
if (client->exp && client->exp->common.ctx) {
|
|
qio_channel_attach_aio_context(client->ioc, client->exp->common.ctx);
|
|
}
|
|
|
|
assert(!client->optlen);
|
|
trace_nbd_negotiate_success();
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* nbd_read_eof
|
|
* Tries to read @size bytes from @ioc. This is a local implementation of
|
|
* qio_channel_readv_all_eof. We have it here because we need it to be
|
|
* interruptible and to know when the coroutine is yielding.
|
|
* Returns 1 on success
|
|
* 0 on eof, when no data was read (errp is not set)
|
|
* negative errno on failure (errp is set)
|
|
*/
|
|
static inline int coroutine_fn
|
|
nbd_read_eof(NBDClient *client, void *buffer, size_t size, Error **errp)
|
|
{
|
|
bool partial = false;
|
|
|
|
assert(size);
|
|
while (size > 0) {
|
|
struct iovec iov = { .iov_base = buffer, .iov_len = size };
|
|
ssize_t len;
|
|
|
|
len = qio_channel_readv(client->ioc, &iov, 1, errp);
|
|
if (len == QIO_CHANNEL_ERR_BLOCK) {
|
|
client->read_yielding = true;
|
|
qio_channel_yield(client->ioc, G_IO_IN);
|
|
client->read_yielding = false;
|
|
if (client->quiescing) {
|
|
return -EAGAIN;
|
|
}
|
|
continue;
|
|
} else if (len < 0) {
|
|
return -EIO;
|
|
} else if (len == 0) {
|
|
if (partial) {
|
|
error_setg(errp,
|
|
"Unexpected end-of-file before all bytes were read");
|
|
return -EIO;
|
|
} else {
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
partial = true;
|
|
size -= len;
|
|
buffer = (uint8_t *) buffer + len;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static int nbd_receive_request(NBDClient *client, NBDRequest *request,
|
|
Error **errp)
|
|
{
|
|
uint8_t buf[NBD_REQUEST_SIZE];
|
|
uint32_t magic;
|
|
int ret;
|
|
|
|
ret = nbd_read_eof(client, buf, sizeof(buf), errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
if (ret == 0) {
|
|
return -EIO;
|
|
}
|
|
|
|
/* 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->tlsauthz);
|
|
if (client->exp) {
|
|
QTAILQ_REMOVE(&client->exp->clients, client, next);
|
|
blk_exp_unref(&client->exp->common);
|
|
}
|
|
g_free(client->export_meta.bitmaps);
|
|
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--;
|
|
|
|
if (client->quiescing && client->nb_requests == 0) {
|
|
aio_wait_kick();
|
|
}
|
|
|
|
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->common.ctx = ctx;
|
|
|
|
QTAILQ_FOREACH(client, &exp->clients, next) {
|
|
qio_channel_attach_aio_context(client->ioc, ctx);
|
|
|
|
assert(client->nb_requests == 0);
|
|
assert(client->recv_coroutine == NULL);
|
|
assert(client->send_coroutine == NULL);
|
|
}
|
|
}
|
|
|
|
static void blk_aio_detach(void *opaque)
|
|
{
|
|
NBDExport *exp = opaque;
|
|
NBDClient *client;
|
|
|
|
trace_nbd_blk_aio_detach(exp->name, exp->common.ctx);
|
|
|
|
QTAILQ_FOREACH(client, &exp->clients, next) {
|
|
qio_channel_detach_aio_context(client->ioc);
|
|
}
|
|
|
|
exp->common.ctx = NULL;
|
|
}
|
|
|
|
static void nbd_drained_begin(void *opaque)
|
|
{
|
|
NBDExport *exp = opaque;
|
|
NBDClient *client;
|
|
|
|
QTAILQ_FOREACH(client, &exp->clients, next) {
|
|
client->quiescing = true;
|
|
}
|
|
}
|
|
|
|
static void nbd_drained_end(void *opaque)
|
|
{
|
|
NBDExport *exp = opaque;
|
|
NBDClient *client;
|
|
|
|
QTAILQ_FOREACH(client, &exp->clients, next) {
|
|
client->quiescing = false;
|
|
nbd_client_receive_next_request(client);
|
|
}
|
|
}
|
|
|
|
static bool nbd_drained_poll(void *opaque)
|
|
{
|
|
NBDExport *exp = opaque;
|
|
NBDClient *client;
|
|
|
|
QTAILQ_FOREACH(client, &exp->clients, next) {
|
|
if (client->nb_requests != 0) {
|
|
/*
|
|
* If there's a coroutine waiting for a request on nbd_read_eof()
|
|
* enter it here so we don't depend on the client to wake it up.
|
|
*/
|
|
if (client->recv_coroutine != NULL && client->read_yielding) {
|
|
qemu_aio_coroutine_enter(exp->common.ctx,
|
|
client->recv_coroutine);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static void nbd_eject_notifier(Notifier *n, void *data)
|
|
{
|
|
NBDExport *exp = container_of(n, NBDExport, eject_notifier);
|
|
|
|
blk_exp_request_shutdown(&exp->common);
|
|
}
|
|
|
|
void nbd_export_set_on_eject_blk(BlockExport *exp, BlockBackend *blk)
|
|
{
|
|
NBDExport *nbd_exp = container_of(exp, NBDExport, common);
|
|
assert(exp->drv == &blk_exp_nbd);
|
|
assert(nbd_exp->eject_notifier_blk == NULL);
|
|
|
|
blk_ref(blk);
|
|
nbd_exp->eject_notifier_blk = blk;
|
|
nbd_exp->eject_notifier.notify = nbd_eject_notifier;
|
|
blk_add_remove_bs_notifier(blk, &nbd_exp->eject_notifier);
|
|
}
|
|
|
|
static const BlockDevOps nbd_block_ops = {
|
|
.drained_begin = nbd_drained_begin,
|
|
.drained_end = nbd_drained_end,
|
|
.drained_poll = nbd_drained_poll,
|
|
};
|
|
|
|
static int nbd_export_create(BlockExport *blk_exp, BlockExportOptions *exp_args,
|
|
Error **errp)
|
|
{
|
|
NBDExport *exp = container_of(blk_exp, NBDExport, common);
|
|
BlockExportOptionsNbd *arg = &exp_args->u.nbd;
|
|
BlockBackend *blk = blk_exp->blk;
|
|
int64_t size;
|
|
uint64_t perm, shared_perm;
|
|
bool readonly = !exp_args->writable;
|
|
BlockDirtyBitmapOrStrList *bitmaps;
|
|
size_t i;
|
|
int ret;
|
|
|
|
assert(exp_args->type == BLOCK_EXPORT_TYPE_NBD);
|
|
|
|
if (!nbd_server_is_running()) {
|
|
error_setg(errp, "NBD server not running");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (!arg->has_name) {
|
|
arg->name = exp_args->node_name;
|
|
}
|
|
|
|
if (strlen(arg->name) > NBD_MAX_STRING_SIZE) {
|
|
error_setg(errp, "export name '%s' too long", arg->name);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (arg->description && strlen(arg->description) > NBD_MAX_STRING_SIZE) {
|
|
error_setg(errp, "description '%s' too long", arg->description);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (nbd_export_find(arg->name)) {
|
|
error_setg(errp, "NBD server already has export named '%s'", arg->name);
|
|
return -EEXIST;
|
|
}
|
|
|
|
size = blk_getlength(blk);
|
|
if (size < 0) {
|
|
error_setg_errno(errp, -size,
|
|
"Failed to determine the NBD export's length");
|
|
return size;
|
|
}
|
|
|
|
/* Don't allow resize while the NBD server is running, otherwise we don't
|
|
* care what happens with the node. */
|
|
blk_get_perm(blk, &perm, &shared_perm);
|
|
ret = blk_set_perm(blk, perm, shared_perm & ~BLK_PERM_RESIZE, errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
QTAILQ_INIT(&exp->clients);
|
|
exp->name = g_strdup(arg->name);
|
|
exp->description = g_strdup(arg->description);
|
|
exp->nbdflags = (NBD_FLAG_HAS_FLAGS | NBD_FLAG_SEND_FLUSH |
|
|
NBD_FLAG_SEND_FUA | NBD_FLAG_SEND_CACHE);
|
|
|
|
if (nbd_server_max_connections() != 1) {
|
|
exp->nbdflags |= NBD_FLAG_CAN_MULTI_CONN;
|
|
}
|
|
if (readonly) {
|
|
exp->nbdflags |= NBD_FLAG_READ_ONLY;
|
|
} else {
|
|
exp->nbdflags |= (NBD_FLAG_SEND_TRIM | NBD_FLAG_SEND_WRITE_ZEROES |
|
|
NBD_FLAG_SEND_FAST_ZERO);
|
|
}
|
|
exp->size = QEMU_ALIGN_DOWN(size, BDRV_SECTOR_SIZE);
|
|
|
|
for (bitmaps = arg->bitmaps; bitmaps; bitmaps = bitmaps->next) {
|
|
exp->nr_export_bitmaps++;
|
|
}
|
|
exp->export_bitmaps = g_new0(BdrvDirtyBitmap *, exp->nr_export_bitmaps);
|
|
for (i = 0, bitmaps = arg->bitmaps; bitmaps;
|
|
i++, bitmaps = bitmaps->next)
|
|
{
|
|
const char *bitmap;
|
|
BlockDriverState *bs = blk_bs(blk);
|
|
BdrvDirtyBitmap *bm = NULL;
|
|
|
|
switch (bitmaps->value->type) {
|
|
case QTYPE_QSTRING:
|
|
bitmap = bitmaps->value->u.local;
|
|
while (bs) {
|
|
bm = bdrv_find_dirty_bitmap(bs, bitmap);
|
|
if (bm != NULL) {
|
|
break;
|
|
}
|
|
|
|
bs = bdrv_filter_or_cow_bs(bs);
|
|
}
|
|
|
|
if (bm == NULL) {
|
|
ret = -ENOENT;
|
|
error_setg(errp, "Bitmap '%s' is not found",
|
|
bitmaps->value->u.local);
|
|
goto fail;
|
|
}
|
|
|
|
if (readonly && bdrv_is_writable(bs) &&
|
|
bdrv_dirty_bitmap_enabled(bm)) {
|
|
ret = -EINVAL;
|
|
error_setg(errp, "Enabled bitmap '%s' incompatible with "
|
|
"readonly export", bitmap);
|
|
goto fail;
|
|
}
|
|
break;
|
|
case QTYPE_QDICT:
|
|
bitmap = bitmaps->value->u.external.name;
|
|
bm = block_dirty_bitmap_lookup(bitmaps->value->u.external.node,
|
|
bitmap, NULL, errp);
|
|
if (!bm) {
|
|
ret = -ENOENT;
|
|
goto fail;
|
|
}
|
|
break;
|
|
default:
|
|
abort();
|
|
}
|
|
|
|
assert(bm);
|
|
|
|
if (bdrv_dirty_bitmap_check(bm, BDRV_BITMAP_ALLOW_RO, errp)) {
|
|
ret = -EINVAL;
|
|
goto fail;
|
|
}
|
|
|
|
exp->export_bitmaps[i] = bm;
|
|
assert(strlen(bitmap) <= BDRV_BITMAP_MAX_NAME_SIZE);
|
|
}
|
|
|
|
/* Mark bitmaps busy in a separate loop, to simplify roll-back concerns. */
|
|
for (i = 0; i < exp->nr_export_bitmaps; i++) {
|
|
bdrv_dirty_bitmap_set_busy(exp->export_bitmaps[i], true);
|
|
}
|
|
|
|
exp->allocation_depth = arg->allocation_depth;
|
|
|
|
/*
|
|
* We need to inhibit request queuing in the block layer to ensure we can
|
|
* be properly quiesced when entering a drained section, as our coroutines
|
|
* servicing pending requests might enter blk_pread().
|
|
*/
|
|
blk_set_disable_request_queuing(blk, true);
|
|
|
|
blk_add_aio_context_notifier(blk, blk_aio_attached, blk_aio_detach, exp);
|
|
|
|
blk_set_dev_ops(blk, &nbd_block_ops, exp);
|
|
|
|
QTAILQ_INSERT_TAIL(&exports, exp, next);
|
|
|
|
return 0;
|
|
|
|
fail:
|
|
g_free(exp->export_bitmaps);
|
|
g_free(exp->name);
|
|
g_free(exp->description);
|
|
return ret;
|
|
}
|
|
|
|
NBDExport *nbd_export_find(const char *name)
|
|
{
|
|
NBDExport *exp;
|
|
QTAILQ_FOREACH(exp, &exports, next) {
|
|
if (strcmp(name, exp->name) == 0) {
|
|
return exp;
|
|
}
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
AioContext *
|
|
nbd_export_aio_context(NBDExport *exp)
|
|
{
|
|
return exp->common.ctx;
|
|
}
|
|
|
|
static void nbd_export_request_shutdown(BlockExport *blk_exp)
|
|
{
|
|
NBDExport *exp = container_of(blk_exp, NBDExport, common);
|
|
NBDClient *client, *next;
|
|
|
|
blk_exp_ref(&exp->common);
|
|
/*
|
|
* TODO: Should we expand QMP NbdServerRemoveNode enum to allow a
|
|
* close mode that stops advertising the export to new clients but
|
|
* still permits existing clients to run to completion? Because of
|
|
* that possibility, nbd_export_close() can be called more than
|
|
* once on an export.
|
|
*/
|
|
QTAILQ_FOREACH_SAFE(client, &exp->clients, next, next) {
|
|
client_close(client, true);
|
|
}
|
|
if (exp->name) {
|
|
g_free(exp->name);
|
|
exp->name = NULL;
|
|
QTAILQ_REMOVE(&exports, exp, next);
|
|
}
|
|
blk_exp_unref(&exp->common);
|
|
}
|
|
|
|
static void nbd_export_delete(BlockExport *blk_exp)
|
|
{
|
|
size_t i;
|
|
NBDExport *exp = container_of(blk_exp, NBDExport, common);
|
|
|
|
assert(exp->name == NULL);
|
|
assert(QTAILQ_EMPTY(&exp->clients));
|
|
|
|
g_free(exp->description);
|
|
exp->description = NULL;
|
|
|
|
if (exp->common.blk) {
|
|
if (exp->eject_notifier_blk) {
|
|
notifier_remove(&exp->eject_notifier);
|
|
blk_unref(exp->eject_notifier_blk);
|
|
}
|
|
blk_remove_aio_context_notifier(exp->common.blk, blk_aio_attached,
|
|
blk_aio_detach, exp);
|
|
blk_set_disable_request_queuing(exp->common.blk, false);
|
|
}
|
|
|
|
for (i = 0; i < exp->nr_export_bitmaps; i++) {
|
|
bdrv_dirty_bitmap_set_busy(exp->export_bitmaps[i], false);
|
|
}
|
|
}
|
|
|
|
const BlockExportDriver blk_exp_nbd = {
|
|
.type = BLOCK_EXPORT_TYPE_NBD,
|
|
.instance_size = sizeof(NBDExport),
|
|
.create = nbd_export_create,
|
|
.delete = nbd_export_delete,
|
|
.request_shutdown = nbd_export_request_shutdown,
|
|
};
|
|
|
|
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->common.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->common.blk, offset + progress, pnum,
|
|
data + progress, 0);
|
|
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;
|
|
}
|
|
|
|
typedef struct NBDExtentArray {
|
|
NBDExtent *extents;
|
|
unsigned int nb_alloc;
|
|
unsigned int count;
|
|
uint64_t total_length;
|
|
bool can_add;
|
|
bool converted_to_be;
|
|
} NBDExtentArray;
|
|
|
|
static NBDExtentArray *nbd_extent_array_new(unsigned int nb_alloc)
|
|
{
|
|
NBDExtentArray *ea = g_new0(NBDExtentArray, 1);
|
|
|
|
ea->nb_alloc = nb_alloc;
|
|
ea->extents = g_new(NBDExtent, nb_alloc);
|
|
ea->can_add = true;
|
|
|
|
return ea;
|
|
}
|
|
|
|
static void nbd_extent_array_free(NBDExtentArray *ea)
|
|
{
|
|
g_free(ea->extents);
|
|
g_free(ea);
|
|
}
|
|
G_DEFINE_AUTOPTR_CLEANUP_FUNC(NBDExtentArray, nbd_extent_array_free)
|
|
|
|
/* Further modifications of the array after conversion are abandoned */
|
|
static void nbd_extent_array_convert_to_be(NBDExtentArray *ea)
|
|
{
|
|
int i;
|
|
|
|
assert(!ea->converted_to_be);
|
|
ea->can_add = false;
|
|
ea->converted_to_be = true;
|
|
|
|
for (i = 0; i < ea->count; i++) {
|
|
ea->extents[i].flags = cpu_to_be32(ea->extents[i].flags);
|
|
ea->extents[i].length = cpu_to_be32(ea->extents[i].length);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Add extent to NBDExtentArray. If extent can't be added (no available space),
|
|
* return -1.
|
|
* For safety, when returning -1 for the first time, .can_add is set to false,
|
|
* and further calls to nbd_extent_array_add() will crash.
|
|
* (this avoids the situation where a caller ignores failure to add one extent,
|
|
* where adding another extent that would squash into the last array entry
|
|
* would result in an incorrect range reported to the client)
|
|
*/
|
|
static int nbd_extent_array_add(NBDExtentArray *ea,
|
|
uint32_t length, uint32_t flags)
|
|
{
|
|
assert(ea->can_add);
|
|
|
|
if (!length) {
|
|
return 0;
|
|
}
|
|
|
|
/* Extend previous extent if flags are the same */
|
|
if (ea->count > 0 && flags == ea->extents[ea->count - 1].flags) {
|
|
uint64_t sum = (uint64_t)length + ea->extents[ea->count - 1].length;
|
|
|
|
if (sum <= UINT32_MAX) {
|
|
ea->extents[ea->count - 1].length = sum;
|
|
ea->total_length += length;
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
if (ea->count >= ea->nb_alloc) {
|
|
ea->can_add = false;
|
|
return -1;
|
|
}
|
|
|
|
ea->total_length += length;
|
|
ea->extents[ea->count] = (NBDExtent) {.length = length, .flags = flags};
|
|
ea->count++;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int blockstatus_to_extents(BlockDriverState *bs, uint64_t offset,
|
|
uint64_t bytes, NBDExtentArray *ea)
|
|
{
|
|
while (bytes) {
|
|
uint32_t flags;
|
|
int64_t num;
|
|
int ret = bdrv_block_status_above(bs, NULL, offset, bytes, &num,
|
|
NULL, NULL);
|
|
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
flags = (ret & BDRV_BLOCK_DATA ? 0 : NBD_STATE_HOLE) |
|
|
(ret & BDRV_BLOCK_ZERO ? NBD_STATE_ZERO : 0);
|
|
|
|
if (nbd_extent_array_add(ea, num, flags) < 0) {
|
|
return 0;
|
|
}
|
|
|
|
offset += num;
|
|
bytes -= num;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int blockalloc_to_extents(BlockDriverState *bs, uint64_t offset,
|
|
uint64_t bytes, NBDExtentArray *ea)
|
|
{
|
|
while (bytes) {
|
|
int64_t num;
|
|
int ret = bdrv_is_allocated_above(bs, NULL, false, offset, bytes,
|
|
&num);
|
|
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
if (nbd_extent_array_add(ea, num, ret) < 0) {
|
|
return 0;
|
|
}
|
|
|
|
offset += num;
|
|
bytes -= num;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* nbd_co_send_extents
|
|
*
|
|
* @ea is converted to BE by the function
|
|
* @last controls whether NBD_REPLY_FLAG_DONE is sent.
|
|
*/
|
|
static int nbd_co_send_extents(NBDClient *client, uint64_t handle,
|
|
NBDExtentArray *ea,
|
|
bool last, uint32_t context_id, Error **errp)
|
|
{
|
|
NBDStructuredMeta chunk;
|
|
struct iovec iov[] = {
|
|
{.iov_base = &chunk, .iov_len = sizeof(chunk)},
|
|
{.iov_base = ea->extents, .iov_len = ea->count * sizeof(ea->extents[0])}
|
|
};
|
|
|
|
nbd_extent_array_convert_to_be(ea);
|
|
|
|
trace_nbd_co_send_extents(handle, ea->count, context_id, ea->total_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_BLOCK_STATUS_EXTENTS;
|
|
g_autoptr(NBDExtentArray) ea = nbd_extent_array_new(nb_extents);
|
|
|
|
if (context_id == NBD_META_ID_BASE_ALLOCATION) {
|
|
ret = blockstatus_to_extents(bs, offset, length, ea);
|
|
} else {
|
|
ret = blockalloc_to_extents(bs, offset, length, ea);
|
|
}
|
|
if (ret < 0) {
|
|
return nbd_co_send_structured_error(
|
|
client, handle, -ret, "can't get block status", errp);
|
|
}
|
|
|
|
return nbd_co_send_extents(client, handle, ea, last, context_id, errp);
|
|
}
|
|
|
|
/* Populate @ea from a dirty bitmap. */
|
|
static void bitmap_to_extents(BdrvDirtyBitmap *bitmap,
|
|
uint64_t offset, uint64_t length,
|
|
NBDExtentArray *es)
|
|
{
|
|
int64_t start, dirty_start, dirty_count;
|
|
int64_t end = offset + length;
|
|
bool full = false;
|
|
|
|
bdrv_dirty_bitmap_lock(bitmap);
|
|
|
|
for (start = offset;
|
|
bdrv_dirty_bitmap_next_dirty_area(bitmap, start, end, INT32_MAX,
|
|
&dirty_start, &dirty_count);
|
|
start = dirty_start + dirty_count)
|
|
{
|
|
if ((nbd_extent_array_add(es, dirty_start - start, 0) < 0) ||
|
|
(nbd_extent_array_add(es, dirty_count, NBD_STATE_DIRTY) < 0))
|
|
{
|
|
full = true;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!full) {
|
|
/* last non dirty extent, nothing to do if array is now full */
|
|
(void) nbd_extent_array_add(es, end - start, 0);
|
|
}
|
|
|
|
bdrv_dirty_bitmap_unlock(bitmap);
|
|
}
|
|
|
|
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)
|
|
{
|
|
unsigned int nb_extents = dont_fragment ? 1 : NBD_MAX_BLOCK_STATUS_EXTENTS;
|
|
g_autoptr(NBDExtentArray) ea = nbd_extent_array_new(nb_extents);
|
|
|
|
bitmap_to_extents(bitmap, offset, length, ea);
|
|
|
|
return nbd_co_send_extents(client, handle, ea, last, context_id, errp);
|
|
}
|
|
|
|
/* nbd_co_receive_request
|
|
* Collect a client request. Return 0 if request looks valid, -EIO to drop
|
|
* connection right away, -EAGAIN to indicate we were interrupted and the
|
|
* channel should be quiesced, 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;
|
|
int ret;
|
|
|
|
g_assert(qemu_in_coroutine());
|
|
assert(client->recv_coroutine == qemu_coroutine_self());
|
|
ret = nbd_receive_request(client, request, errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
if (request->type != NBD_CMD_CACHE) {
|
|
req->data = blk_try_blockalign(client->exp->common.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, "CMD_WRITE data",
|
|
errp) < 0)
|
|
{
|
|
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->len > client->exp->size - request->from) {
|
|
error_setg(errp, "operation past EOF; From: %" PRIu64 ", Len: %" PRIu32
|
|
", Size: %" PRIu64, request->from, request->len,
|
|
client->exp->size);
|
|
return (request->type == NBD_CMD_WRITE ||
|
|
request->type == NBD_CMD_WRITE_ZEROES) ? -ENOSPC : -EINVAL;
|
|
}
|
|
if (client->check_align && !QEMU_IS_ALIGNED(request->from | request->len,
|
|
client->check_align)) {
|
|
/*
|
|
* The block layer gracefully handles unaligned requests, but
|
|
* it's still worth tracing client non-compliance
|
|
*/
|
|
trace_nbd_co_receive_align_compliance(nbd_cmd_lookup(request->type),
|
|
request->from,
|
|
request->len,
|
|
client->check_align);
|
|
}
|
|
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 | NBD_CMD_FLAG_FAST_ZERO;
|
|
} 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);
|
|
|
|
/* XXX: NBD Protocol only documents use of FUA with WRITE */
|
|
if (request->flags & NBD_CMD_FLAG_FUA) {
|
|
ret = blk_co_flush(exp->common.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)
|
|
{
|
|
return nbd_co_send_sparse_read(client, request->handle, request->from,
|
|
data, request->len, errp);
|
|
}
|
|
|
|
ret = blk_pread(exp->common.blk, request->from, request->len, data, 0);
|
|
if (ret < 0) {
|
|
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);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* nbd_do_cmd_cache
|
|
*
|
|
* Handle NBD_CMD_CACHE 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_cache(NBDClient *client, NBDRequest *request,
|
|
Error **errp)
|
|
{
|
|
int ret;
|
|
NBDExport *exp = client->exp;
|
|
|
|
assert(request->type == NBD_CMD_CACHE);
|
|
|
|
ret = blk_co_preadv(exp->common.blk, request->from, request->len,
|
|
NULL, BDRV_REQ_COPY_ON_READ | BDRV_REQ_PREFETCH);
|
|
|
|
return nbd_send_generic_reply(client, request->handle, ret,
|
|
"caching data failed", 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;
|
|
size_t i;
|
|
|
|
switch (request->type) {
|
|
case NBD_CMD_CACHE:
|
|
return nbd_do_cmd_cache(client, request, errp);
|
|
|
|
case NBD_CMD_READ:
|
|
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->common.blk, request->from, request->len, data,
|
|
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;
|
|
}
|
|
if (request->flags & NBD_CMD_FLAG_FAST_ZERO) {
|
|
flags |= BDRV_REQ_NO_FALLBACK;
|
|
}
|
|
ret = blk_pwrite_zeroes(exp->common.blk, request->from, 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->common.blk);
|
|
return nbd_send_generic_reply(client, request->handle, ret,
|
|
"flush failed", errp);
|
|
|
|
case NBD_CMD_TRIM:
|
|
ret = blk_co_pdiscard(exp->common.blk, request->from, request->len);
|
|
if (ret >= 0 && request->flags & NBD_CMD_FLAG_FUA) {
|
|
ret = blk_co_flush(exp->common.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.count) {
|
|
bool dont_fragment = request->flags & NBD_CMD_FLAG_REQ_ONE;
|
|
int contexts_remaining = client->export_meta.count;
|
|
|
|
if (client->export_meta.base_allocation) {
|
|
ret = nbd_co_send_block_status(client, request->handle,
|
|
blk_bs(exp->common.blk),
|
|
request->from,
|
|
request->len, dont_fragment,
|
|
!--contexts_remaining,
|
|
NBD_META_ID_BASE_ALLOCATION,
|
|
errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
if (client->export_meta.allocation_depth) {
|
|
ret = nbd_co_send_block_status(client, request->handle,
|
|
blk_bs(exp->common.blk),
|
|
request->from, request->len,
|
|
dont_fragment,
|
|
!--contexts_remaining,
|
|
NBD_META_ID_ALLOCATION_DEPTH,
|
|
errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
for (i = 0; i < client->exp->nr_export_bitmaps; i++) {
|
|
if (!client->export_meta.bitmaps[i]) {
|
|
continue;
|
|
}
|
|
ret = nbd_co_send_bitmap(client, request->handle,
|
|
client->exp->export_bitmaps[i],
|
|
request->from, request->len,
|
|
dont_fragment, !--contexts_remaining,
|
|
NBD_META_ID_DIRTY_BITMAP + i, errp);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
assert(!contexts_remaining);
|
|
|
|
return 0;
|
|
} 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;
|
|
}
|
|
|
|
if (client->quiescing) {
|
|
/*
|
|
* We're switching between AIO contexts. Don't attempt to receive a new
|
|
* request and kick the main context which may be waiting for us.
|
|
*/
|
|
nbd_client_put(client);
|
|
client->recv_coroutine = NULL;
|
|
aio_wait_kick();
|
|
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;
|
|
}
|
|
|
|
if (ret == -EAGAIN) {
|
|
assert(client->quiescing);
|
|
goto done;
|
|
}
|
|
|
|
nbd_client_receive_next_request(client);
|
|
if (ret == -EIO) {
|
|
goto disconnect;
|
|
}
|
|
|
|
if (ret < 0) {
|
|
/* It wasn'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 &&
|
|
!client->quiescing) {
|
|
nbd_client_get(client);
|
|
client->recv_coroutine = qemu_coroutine_create(nbd_trip, client);
|
|
aio_co_schedule(client->exp->common.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 *tlsauthz,
|
|
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->tlsauthz = g_strdup(tlsauthz);
|
|
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);
|
|
}
|