From e02cda008591317b1625707ff8e115a4841aa889 Mon Sep 17 00:00:00 2001 From: Timos Ampelikiotis Date: Tue, 10 Oct 2023 11:40:56 +0000 Subject: Introduce Virtio-loopback epsilon release: Epsilon release introduces a new compatibility layer which make virtio-loopback design to work with QEMU and rust-vmm vhost-user backend without require any changes. Signed-off-by: Timos Ampelikiotis Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9 --- block/nbd.c | 2078 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 2078 insertions(+) create mode 100644 block/nbd.c (limited to 'block/nbd.c') diff --git a/block/nbd.c b/block/nbd.c new file mode 100644 index 000000000..5ef462db1 --- /dev/null +++ b/block/nbd.c @@ -0,0 +1,2078 @@ +/* + * QEMU Block driver for NBD + * + * Copyright (c) 2019 Virtuozzo International GmbH. + * Copyright (C) 2016 Red Hat, Inc. + * Copyright (C) 2008 Bull S.A.S. + * Author: Laurent Vivier + * + * Some parts: + * Copyright (C) 2007 Anthony Liguori + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#include "qemu/osdep.h" + +#include "trace.h" +#include "qemu/uri.h" +#include "qemu/option.h" +#include "qemu/cutils.h" +#include "qemu/main-loop.h" +#include "qemu/atomic.h" + +#include "qapi/qapi-visit-sockets.h" +#include "qapi/qmp/qstring.h" +#include "qapi/clone-visitor.h" + +#include "block/qdict.h" +#include "block/nbd.h" +#include "block/block_int.h" +#include "block/coroutines.h" + +#include "qemu/yank.h" + +#define EN_OPTSTR ":exportname=" +#define MAX_NBD_REQUESTS 16 + +#define HANDLE_TO_INDEX(bs, handle) ((handle) ^ (uint64_t)(intptr_t)(bs)) +#define INDEX_TO_HANDLE(bs, index) ((index) ^ (uint64_t)(intptr_t)(bs)) + +typedef struct { + Coroutine *coroutine; + uint64_t offset; /* original offset of the request */ + bool receiving; /* sleeping in the yield in nbd_receive_replies */ + bool reply_possible; /* reply header not yet received */ +} NBDClientRequest; + +typedef enum NBDClientState { + NBD_CLIENT_CONNECTING_WAIT, + NBD_CLIENT_CONNECTING_NOWAIT, + NBD_CLIENT_CONNECTED, + NBD_CLIENT_QUIT +} NBDClientState; + +typedef struct BDRVNBDState { + QIOChannel *ioc; /* The current I/O channel */ + NBDExportInfo info; + + CoMutex send_mutex; + CoQueue free_sema; + + CoMutex receive_mutex; + int in_flight; + NBDClientState state; + + QEMUTimer *reconnect_delay_timer; + + NBDClientRequest requests[MAX_NBD_REQUESTS]; + NBDReply reply; + BlockDriverState *bs; + + /* Connection parameters */ + uint32_t reconnect_delay; + SocketAddress *saddr; + char *export, *tlscredsid; + QCryptoTLSCreds *tlscreds; + const char *hostname; + char *x_dirty_bitmap; + bool alloc_depth; + + NBDClientConnection *conn; +} BDRVNBDState; + +static void nbd_yank(void *opaque); + +static void nbd_clear_bdrvstate(BlockDriverState *bs) +{ + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; + + nbd_client_connection_release(s->conn); + s->conn = NULL; + + yank_unregister_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name)); + + object_unref(OBJECT(s->tlscreds)); + qapi_free_SocketAddress(s->saddr); + s->saddr = NULL; + g_free(s->export); + s->export = NULL; + g_free(s->tlscredsid); + s->tlscredsid = NULL; + g_free(s->x_dirty_bitmap); + s->x_dirty_bitmap = NULL; +} + +static bool nbd_client_connected(BDRVNBDState *s) +{ + return qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTED; +} + +static bool nbd_recv_coroutine_wake_one(NBDClientRequest *req) +{ + if (req->receiving) { + req->receiving = false; + aio_co_wake(req->coroutine); + return true; + } + + return false; +} + +static void nbd_recv_coroutines_wake(BDRVNBDState *s, bool all) +{ + int i; + + for (i = 0; i < MAX_NBD_REQUESTS; i++) { + if (nbd_recv_coroutine_wake_one(&s->requests[i]) && !all) { + return; + } + } +} + +static void nbd_channel_error(BDRVNBDState *s, int ret) +{ + if (nbd_client_connected(s)) { + qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); + } + + if (ret == -EIO) { + if (nbd_client_connected(s)) { + s->state = s->reconnect_delay ? NBD_CLIENT_CONNECTING_WAIT : + NBD_CLIENT_CONNECTING_NOWAIT; + } + } else { + s->state = NBD_CLIENT_QUIT; + } + + nbd_recv_coroutines_wake(s, true); +} + +static void reconnect_delay_timer_del(BDRVNBDState *s) +{ + if (s->reconnect_delay_timer) { + timer_free(s->reconnect_delay_timer); + s->reconnect_delay_timer = NULL; + } +} + +static void reconnect_delay_timer_cb(void *opaque) +{ + BDRVNBDState *s = opaque; + + if (qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT) { + s->state = NBD_CLIENT_CONNECTING_NOWAIT; + nbd_co_establish_connection_cancel(s->conn); + while (qemu_co_enter_next(&s->free_sema, NULL)) { + /* Resume all queued requests */ + } + } + + reconnect_delay_timer_del(s); +} + +static void reconnect_delay_timer_init(BDRVNBDState *s, uint64_t expire_time_ns) +{ + if (qatomic_load_acquire(&s->state) != NBD_CLIENT_CONNECTING_WAIT) { + return; + } + + assert(!s->reconnect_delay_timer); + s->reconnect_delay_timer = aio_timer_new(bdrv_get_aio_context(s->bs), + QEMU_CLOCK_REALTIME, + SCALE_NS, + reconnect_delay_timer_cb, s); + timer_mod(s->reconnect_delay_timer, expire_time_ns); +} + +static void nbd_teardown_connection(BlockDriverState *bs) +{ + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; + + assert(!s->in_flight); + + if (s->ioc) { + qio_channel_shutdown(s->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); + yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), + nbd_yank, s->bs); + object_unref(OBJECT(s->ioc)); + s->ioc = NULL; + } + + s->state = NBD_CLIENT_QUIT; +} + +static bool nbd_client_connecting(BDRVNBDState *s) +{ + NBDClientState state = qatomic_load_acquire(&s->state); + return state == NBD_CLIENT_CONNECTING_WAIT || + state == NBD_CLIENT_CONNECTING_NOWAIT; +} + +static bool nbd_client_connecting_wait(BDRVNBDState *s) +{ + return qatomic_load_acquire(&s->state) == NBD_CLIENT_CONNECTING_WAIT; +} + +/* + * Update @bs with information learned during a completed negotiation process. + * Return failure if the server's advertised options are incompatible with the + * client's needs. + */ +static int nbd_handle_updated_info(BlockDriverState *bs, Error **errp) +{ + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; + int ret; + + if (s->x_dirty_bitmap) { + if (!s->info.base_allocation) { + error_setg(errp, "requested x-dirty-bitmap %s not found", + s->x_dirty_bitmap); + return -EINVAL; + } + if (strcmp(s->x_dirty_bitmap, "qemu:allocation-depth") == 0) { + s->alloc_depth = true; + } + } + + if (s->info.flags & NBD_FLAG_READ_ONLY) { + ret = bdrv_apply_auto_read_only(bs, "NBD export is read-only", errp); + if (ret < 0) { + return ret; + } + } + + if (s->info.flags & NBD_FLAG_SEND_FUA) { + bs->supported_write_flags = BDRV_REQ_FUA; + bs->supported_zero_flags |= BDRV_REQ_FUA; + } + + if (s->info.flags & NBD_FLAG_SEND_WRITE_ZEROES) { + bs->supported_zero_flags |= BDRV_REQ_MAY_UNMAP; + if (s->info.flags & NBD_FLAG_SEND_FAST_ZERO) { + bs->supported_zero_flags |= BDRV_REQ_NO_FALLBACK; + } + } + + trace_nbd_client_handshake_success(s->export); + + return 0; +} + +int coroutine_fn nbd_co_do_establish_connection(BlockDriverState *bs, + Error **errp) +{ + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; + int ret; + bool blocking = nbd_client_connecting_wait(s); + + assert(!s->ioc); + + s->ioc = nbd_co_establish_connection(s->conn, &s->info, blocking, errp); + if (!s->ioc) { + return -ECONNREFUSED; + } + + yank_register_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), nbd_yank, + bs); + + ret = nbd_handle_updated_info(s->bs, NULL); + if (ret < 0) { + /* + * We have connected, but must fail for other reasons. + * Send NBD_CMD_DISC as a courtesy to the server. + */ + NBDRequest request = { .type = NBD_CMD_DISC }; + + nbd_send_request(s->ioc, &request); + + yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), + nbd_yank, bs); + object_unref(OBJECT(s->ioc)); + s->ioc = NULL; + + return ret; + } + + qio_channel_set_blocking(s->ioc, false, NULL); + qio_channel_attach_aio_context(s->ioc, bdrv_get_aio_context(bs)); + + /* successfully connected */ + s->state = NBD_CLIENT_CONNECTED; + qemu_co_queue_restart_all(&s->free_sema); + + return 0; +} + +/* called under s->send_mutex */ +static coroutine_fn void nbd_reconnect_attempt(BDRVNBDState *s) +{ + assert(nbd_client_connecting(s)); + assert(s->in_flight == 0); + + if (nbd_client_connecting_wait(s) && s->reconnect_delay && + !s->reconnect_delay_timer) + { + /* + * It's first reconnect attempt after switching to + * NBD_CLIENT_CONNECTING_WAIT + */ + reconnect_delay_timer_init(s, + qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + + s->reconnect_delay * NANOSECONDS_PER_SECOND); + } + + /* + * Now we are sure that nobody is accessing the channel, and no one will + * try until we set the state to CONNECTED. + */ + + /* Finalize previous connection if any */ + if (s->ioc) { + qio_channel_detach_aio_context(QIO_CHANNEL(s->ioc)); + yank_unregister_function(BLOCKDEV_YANK_INSTANCE(s->bs->node_name), + nbd_yank, s->bs); + object_unref(OBJECT(s->ioc)); + s->ioc = NULL; + } + + nbd_co_do_establish_connection(s->bs, NULL); +} + +static coroutine_fn int nbd_receive_replies(BDRVNBDState *s, uint64_t handle) +{ + int ret; + uint64_t ind = HANDLE_TO_INDEX(s, handle), ind2; + QEMU_LOCK_GUARD(&s->receive_mutex); + + while (true) { + if (s->reply.handle == handle) { + /* We are done */ + return 0; + } + + if (!nbd_client_connected(s)) { + return -EIO; + } + + if (s->reply.handle != 0) { + /* + * Some other request is being handled now. It should already be + * woken by whoever set s->reply.handle (or never wait in this + * yield). So, we should not wake it here. + */ + ind2 = HANDLE_TO_INDEX(s, s->reply.handle); + assert(!s->requests[ind2].receiving); + + s->requests[ind].receiving = true; + qemu_co_mutex_unlock(&s->receive_mutex); + + qemu_coroutine_yield(); + /* + * We may be woken for 3 reasons: + * 1. From this function, executing in parallel coroutine, when our + * handle is received. + * 2. From nbd_channel_error(), when connection is lost. + * 3. From nbd_co_receive_one_chunk(), when previous request is + * finished and s->reply.handle set to 0. + * Anyway, it's OK to lock the mutex and go to the next iteration. + */ + + qemu_co_mutex_lock(&s->receive_mutex); + assert(!s->requests[ind].receiving); + continue; + } + + /* We are under mutex and handle is 0. We have to do the dirty work. */ + assert(s->reply.handle == 0); + ret = nbd_receive_reply(s->bs, s->ioc, &s->reply, NULL); + if (ret <= 0) { + ret = ret ? ret : -EIO; + nbd_channel_error(s, ret); + return ret; + } + if (nbd_reply_is_structured(&s->reply) && !s->info.structured_reply) { + nbd_channel_error(s, -EINVAL); + return -EINVAL; + } + if (s->reply.handle == handle) { + /* We are done */ + return 0; + } + ind2 = HANDLE_TO_INDEX(s, s->reply.handle); + if (ind2 >= MAX_NBD_REQUESTS || !s->requests[ind2].reply_possible) { + nbd_channel_error(s, -EINVAL); + return -EINVAL; + } + nbd_recv_coroutine_wake_one(&s->requests[ind2]); + } +} + +static int nbd_co_send_request(BlockDriverState *bs, + NBDRequest *request, + QEMUIOVector *qiov) +{ + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; + int rc, i = -1; + + qemu_co_mutex_lock(&s->send_mutex); + + while (s->in_flight == MAX_NBD_REQUESTS || + (!nbd_client_connected(s) && s->in_flight > 0)) + { + qemu_co_queue_wait(&s->free_sema, &s->send_mutex); + } + + if (nbd_client_connecting(s)) { + nbd_reconnect_attempt(s); + } + + if (!nbd_client_connected(s)) { + rc = -EIO; + goto err; + } + + s->in_flight++; + + for (i = 0; i < MAX_NBD_REQUESTS; i++) { + if (s->requests[i].coroutine == NULL) { + break; + } + } + + g_assert(qemu_in_coroutine()); + assert(i < MAX_NBD_REQUESTS); + + s->requests[i].coroutine = qemu_coroutine_self(); + s->requests[i].offset = request->from; + s->requests[i].receiving = false; + s->requests[i].reply_possible = true; + + request->handle = INDEX_TO_HANDLE(s, i); + + assert(s->ioc); + + if (qiov) { + qio_channel_set_cork(s->ioc, true); + rc = nbd_send_request(s->ioc, request); + if (nbd_client_connected(s) && rc >= 0) { + if (qio_channel_writev_all(s->ioc, qiov->iov, qiov->niov, + NULL) < 0) { + rc = -EIO; + } + } else if (rc >= 0) { + rc = -EIO; + } + qio_channel_set_cork(s->ioc, false); + } else { + rc = nbd_send_request(s->ioc, request); + } + +err: + if (rc < 0) { + nbd_channel_error(s, rc); + if (i != -1) { + s->requests[i].coroutine = NULL; + s->in_flight--; + qemu_co_queue_next(&s->free_sema); + } + } + qemu_co_mutex_unlock(&s->send_mutex); + return rc; +} + +static inline uint16_t payload_advance16(uint8_t **payload) +{ + *payload += 2; + return lduw_be_p(*payload - 2); +} + +static inline uint32_t payload_advance32(uint8_t **payload) +{ + *payload += 4; + return ldl_be_p(*payload - 4); +} + +static inline uint64_t payload_advance64(uint8_t **payload) +{ + *payload += 8; + return ldq_be_p(*payload - 8); +} + +static int nbd_parse_offset_hole_payload(BDRVNBDState *s, + NBDStructuredReplyChunk *chunk, + uint8_t *payload, uint64_t orig_offset, + QEMUIOVector *qiov, Error **errp) +{ + uint64_t offset; + uint32_t hole_size; + + if (chunk->length != sizeof(offset) + sizeof(hole_size)) { + error_setg(errp, "Protocol error: invalid payload for " + "NBD_REPLY_TYPE_OFFSET_HOLE"); + return -EINVAL; + } + + offset = payload_advance64(&payload); + hole_size = payload_advance32(&payload); + + if (!hole_size || offset < orig_offset || hole_size > qiov->size || + offset > orig_offset + qiov->size - hole_size) { + error_setg(errp, "Protocol error: server sent chunk exceeding requested" + " region"); + return -EINVAL; + } + if (s->info.min_block && + !QEMU_IS_ALIGNED(hole_size, s->info.min_block)) { + trace_nbd_structured_read_compliance("hole"); + } + + qemu_iovec_memset(qiov, offset - orig_offset, 0, hole_size); + + return 0; +} + +/* + * nbd_parse_blockstatus_payload + * Based on our request, we expect only one extent in reply, for the + * base:allocation context. + */ +static int nbd_parse_blockstatus_payload(BDRVNBDState *s, + NBDStructuredReplyChunk *chunk, + uint8_t *payload, uint64_t orig_length, + NBDExtent *extent, Error **errp) +{ + uint32_t context_id; + + /* The server succeeded, so it must have sent [at least] one extent */ + if (chunk->length < sizeof(context_id) + sizeof(*extent)) { + error_setg(errp, "Protocol error: invalid payload for " + "NBD_REPLY_TYPE_BLOCK_STATUS"); + return -EINVAL; + } + + context_id = payload_advance32(&payload); + if (s->info.context_id != context_id) { + error_setg(errp, "Protocol error: unexpected context id %d for " + "NBD_REPLY_TYPE_BLOCK_STATUS, when negotiated context " + "id is %d", context_id, + s->info.context_id); + return -EINVAL; + } + + extent->length = payload_advance32(&payload); + extent->flags = payload_advance32(&payload); + + if (extent->length == 0) { + error_setg(errp, "Protocol error: server sent status chunk with " + "zero length"); + return -EINVAL; + } + + /* + * A server sending unaligned block status is in violation of the + * protocol, but as qemu-nbd 3.1 is such a server (at least for + * POSIX files that are not a multiple of 512 bytes, since qemu + * rounds files up to 512-byte multiples but lseek(SEEK_HOLE) + * still sees an implicit hole beyond the real EOF), it's nicer to + * work around the misbehaving server. If the request included + * more than the final unaligned block, truncate it back to an + * aligned result; if the request was only the final block, round + * up to the full block and change the status to fully-allocated + * (always a safe status, even if it loses information). + */ + if (s->info.min_block && !QEMU_IS_ALIGNED(extent->length, + s->info.min_block)) { + trace_nbd_parse_blockstatus_compliance("extent length is unaligned"); + if (extent->length > s->info.min_block) { + extent->length = QEMU_ALIGN_DOWN(extent->length, + s->info.min_block); + } else { + extent->length = s->info.min_block; + extent->flags = 0; + } + } + + /* + * We used NBD_CMD_FLAG_REQ_ONE, so the server should not have + * sent us any more than one extent, nor should it have included + * status beyond our request in that extent. However, it's easy + * enough to ignore the server's noncompliance without killing the + * connection; just ignore trailing extents, and clamp things to + * the length of our request. + */ + if (chunk->length > sizeof(context_id) + sizeof(*extent)) { + trace_nbd_parse_blockstatus_compliance("more than one extent"); + } + if (extent->length > orig_length) { + extent->length = orig_length; + trace_nbd_parse_blockstatus_compliance("extent length too large"); + } + + /* + * HACK: if we are using x-dirty-bitmaps to access + * qemu:allocation-depth, treat all depths > 2 the same as 2, + * since nbd_client_co_block_status is only expecting the low two + * bits to be set. + */ + if (s->alloc_depth && extent->flags > 2) { + extent->flags = 2; + } + + return 0; +} + +/* + * nbd_parse_error_payload + * on success @errp contains message describing nbd error reply + */ +static int nbd_parse_error_payload(NBDStructuredReplyChunk *chunk, + uint8_t *payload, int *request_ret, + Error **errp) +{ + uint32_t error; + uint16_t message_size; + + assert(chunk->type & (1 << 15)); + + if (chunk->length < sizeof(error) + sizeof(message_size)) { + error_setg(errp, + "Protocol error: invalid payload for structured error"); + return -EINVAL; + } + + error = nbd_errno_to_system_errno(payload_advance32(&payload)); + if (error == 0) { + error_setg(errp, "Protocol error: server sent structured error chunk " + "with error = 0"); + return -EINVAL; + } + + *request_ret = -error; + message_size = payload_advance16(&payload); + + if (message_size > chunk->length - sizeof(error) - sizeof(message_size)) { + error_setg(errp, "Protocol error: server sent structured error chunk " + "with incorrect message size"); + return -EINVAL; + } + + /* TODO: Add a trace point to mention the server complaint */ + + /* TODO handle ERROR_OFFSET */ + + return 0; +} + +static int nbd_co_receive_offset_data_payload(BDRVNBDState *s, + uint64_t orig_offset, + QEMUIOVector *qiov, Error **errp) +{ + QEMUIOVector sub_qiov; + uint64_t offset; + size_t data_size; + int ret; + NBDStructuredReplyChunk *chunk = &s->reply.structured; + + assert(nbd_reply_is_structured(&s->reply)); + + /* The NBD spec requires at least one byte of payload */ + if (chunk->length <= sizeof(offset)) { + error_setg(errp, "Protocol error: invalid payload for " + "NBD_REPLY_TYPE_OFFSET_DATA"); + return -EINVAL; + } + + if (nbd_read64(s->ioc, &offset, "OFFSET_DATA offset", errp) < 0) { + return -EIO; + } + + data_size = chunk->length - sizeof(offset); + assert(data_size); + if (offset < orig_offset || data_size > qiov->size || + offset > orig_offset + qiov->size - data_size) { + error_setg(errp, "Protocol error: server sent chunk exceeding requested" + " region"); + return -EINVAL; + } + if (s->info.min_block && !QEMU_IS_ALIGNED(data_size, s->info.min_block)) { + trace_nbd_structured_read_compliance("data"); + } + + qemu_iovec_init(&sub_qiov, qiov->niov); + qemu_iovec_concat(&sub_qiov, qiov, offset - orig_offset, data_size); + ret = qio_channel_readv_all(s->ioc, sub_qiov.iov, sub_qiov.niov, errp); + qemu_iovec_destroy(&sub_qiov); + + return ret < 0 ? -EIO : 0; +} + +#define NBD_MAX_MALLOC_PAYLOAD 1000 +static coroutine_fn int nbd_co_receive_structured_payload( + BDRVNBDState *s, void **payload, Error **errp) +{ + int ret; + uint32_t len; + + assert(nbd_reply_is_structured(&s->reply)); + + len = s->reply.structured.length; + + if (len == 0) { + return 0; + } + + if (payload == NULL) { + error_setg(errp, "Unexpected structured payload"); + return -EINVAL; + } + + if (len > NBD_MAX_MALLOC_PAYLOAD) { + error_setg(errp, "Payload too large"); + return -EINVAL; + } + + *payload = g_new(char, len); + ret = nbd_read(s->ioc, *payload, len, "structured payload", errp); + if (ret < 0) { + g_free(*payload); + *payload = NULL; + return ret; + } + + return 0; +} + +/* + * nbd_co_do_receive_one_chunk + * for simple reply: + * set request_ret to received reply error + * if qiov is not NULL: read payload to @qiov + * for structured reply chunk: + * if error chunk: read payload, set @request_ret, do not set @payload + * else if offset_data chunk: read payload data to @qiov, do not set @payload + * else: read payload to @payload + * + * If function fails, @errp contains corresponding error message, and the + * connection with the server is suspect. If it returns 0, then the + * transaction succeeded (although @request_ret may be a negative errno + * corresponding to the server's error reply), and errp is unchanged. + */ +static coroutine_fn int nbd_co_do_receive_one_chunk( + BDRVNBDState *s, uint64_t handle, bool only_structured, + int *request_ret, QEMUIOVector *qiov, void **payload, Error **errp) +{ + int ret; + int i = HANDLE_TO_INDEX(s, handle); + void *local_payload = NULL; + NBDStructuredReplyChunk *chunk; + + if (payload) { + *payload = NULL; + } + *request_ret = 0; + + nbd_receive_replies(s, handle); + if (!nbd_client_connected(s)) { + error_setg(errp, "Connection closed"); + return -EIO; + } + assert(s->ioc); + + assert(s->reply.handle == handle); + + if (nbd_reply_is_simple(&s->reply)) { + if (only_structured) { + error_setg(errp, "Protocol error: simple reply when structured " + "reply chunk was expected"); + return -EINVAL; + } + + *request_ret = -nbd_errno_to_system_errno(s->reply.simple.error); + if (*request_ret < 0 || !qiov) { + return 0; + } + + return qio_channel_readv_all(s->ioc, qiov->iov, qiov->niov, + errp) < 0 ? -EIO : 0; + } + + /* handle structured reply chunk */ + assert(s->info.structured_reply); + chunk = &s->reply.structured; + + if (chunk->type == NBD_REPLY_TYPE_NONE) { + if (!(chunk->flags & NBD_REPLY_FLAG_DONE)) { + error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk without" + " NBD_REPLY_FLAG_DONE flag set"); + return -EINVAL; + } + if (chunk->length) { + error_setg(errp, "Protocol error: NBD_REPLY_TYPE_NONE chunk with" + " nonzero length"); + return -EINVAL; + } + return 0; + } + + if (chunk->type == NBD_REPLY_TYPE_OFFSET_DATA) { + if (!qiov) { + error_setg(errp, "Unexpected NBD_REPLY_TYPE_OFFSET_DATA chunk"); + return -EINVAL; + } + + return nbd_co_receive_offset_data_payload(s, s->requests[i].offset, + qiov, errp); + } + + if (nbd_reply_type_is_error(chunk->type)) { + payload = &local_payload; + } + + ret = nbd_co_receive_structured_payload(s, payload, errp); + if (ret < 0) { + return ret; + } + + if (nbd_reply_type_is_error(chunk->type)) { + ret = nbd_parse_error_payload(chunk, local_payload, request_ret, errp); + g_free(local_payload); + return ret; + } + + return 0; +} + +/* + * nbd_co_receive_one_chunk + * Read reply, wake up connection_co and set s->quit if needed. + * Return value is a fatal error code or normal nbd reply error code + */ +static coroutine_fn int nbd_co_receive_one_chunk( + BDRVNBDState *s, uint64_t handle, bool only_structured, + int *request_ret, QEMUIOVector *qiov, NBDReply *reply, void **payload, + Error **errp) +{ + int ret = nbd_co_do_receive_one_chunk(s, handle, only_structured, + request_ret, qiov, payload, errp); + + if (ret < 0) { + memset(reply, 0, sizeof(*reply)); + nbd_channel_error(s, ret); + } else { + /* For assert at loop start in nbd_connection_entry */ + *reply = s->reply; + } + s->reply.handle = 0; + + nbd_recv_coroutines_wake(s, false); + + return ret; +} + +typedef struct NBDReplyChunkIter { + int ret; + int request_ret; + Error *err; + bool done, only_structured; +} NBDReplyChunkIter; + +static void nbd_iter_channel_error(NBDReplyChunkIter *iter, + int ret, Error **local_err) +{ + assert(local_err && *local_err); + assert(ret < 0); + + if (!iter->ret) { + iter->ret = ret; + error_propagate(&iter->err, *local_err); + } else { + error_free(*local_err); + } + + *local_err = NULL; +} + +static void nbd_iter_request_error(NBDReplyChunkIter *iter, int ret) +{ + assert(ret < 0); + + if (!iter->request_ret) { + iter->request_ret = ret; + } +} + +/* + * NBD_FOREACH_REPLY_CHUNK + * The pointer stored in @payload requires g_free() to free it. + */ +#define NBD_FOREACH_REPLY_CHUNK(s, iter, handle, structured, \ + qiov, reply, payload) \ + for (iter = (NBDReplyChunkIter) { .only_structured = structured }; \ + nbd_reply_chunk_iter_receive(s, &iter, handle, qiov, reply, payload);) + +/* + * nbd_reply_chunk_iter_receive + * The pointer stored in @payload requires g_free() to free it. + */ +static bool nbd_reply_chunk_iter_receive(BDRVNBDState *s, + NBDReplyChunkIter *iter, + uint64_t handle, + QEMUIOVector *qiov, NBDReply *reply, + void **payload) +{ + int ret, request_ret; + NBDReply local_reply; + NBDStructuredReplyChunk *chunk; + Error *local_err = NULL; + if (!nbd_client_connected(s)) { + error_setg(&local_err, "Connection closed"); + nbd_iter_channel_error(iter, -EIO, &local_err); + goto break_loop; + } + + if (iter->done) { + /* Previous iteration was last. */ + goto break_loop; + } + + if (reply == NULL) { + reply = &local_reply; + } + + ret = nbd_co_receive_one_chunk(s, handle, iter->only_structured, + &request_ret, qiov, reply, payload, + &local_err); + if (ret < 0) { + nbd_iter_channel_error(iter, ret, &local_err); + } else if (request_ret < 0) { + nbd_iter_request_error(iter, request_ret); + } + + /* Do not execute the body of NBD_FOREACH_REPLY_CHUNK for simple reply. */ + if (nbd_reply_is_simple(reply) || !nbd_client_connected(s)) { + goto break_loop; + } + + chunk = &reply->structured; + iter->only_structured = true; + + if (chunk->type == NBD_REPLY_TYPE_NONE) { + /* NBD_REPLY_FLAG_DONE is already checked in nbd_co_receive_one_chunk */ + assert(chunk->flags & NBD_REPLY_FLAG_DONE); + goto break_loop; + } + + if (chunk->flags & NBD_REPLY_FLAG_DONE) { + /* This iteration is last. */ + iter->done = true; + } + + /* Execute the loop body */ + return true; + +break_loop: + s->requests[HANDLE_TO_INDEX(s, handle)].coroutine = NULL; + + qemu_co_mutex_lock(&s->send_mutex); + s->in_flight--; + qemu_co_queue_next(&s->free_sema); + qemu_co_mutex_unlock(&s->send_mutex); + + return false; +} + +static int nbd_co_receive_return_code(BDRVNBDState *s, uint64_t handle, + int *request_ret, Error **errp) +{ + NBDReplyChunkIter iter; + + NBD_FOREACH_REPLY_CHUNK(s, iter, handle, false, NULL, NULL, NULL) { + /* nbd_reply_chunk_iter_receive does all the work */ + } + + error_propagate(errp, iter.err); + *request_ret = iter.request_ret; + return iter.ret; +} + +static int nbd_co_receive_cmdread_reply(BDRVNBDState *s, uint64_t handle, + uint64_t offset, QEMUIOVector *qiov, + int *request_ret, Error **errp) +{ + NBDReplyChunkIter iter; + NBDReply reply; + void *payload = NULL; + Error *local_err = NULL; + + NBD_FOREACH_REPLY_CHUNK(s, iter, handle, s->info.structured_reply, + qiov, &reply, &payload) + { + int ret; + NBDStructuredReplyChunk *chunk = &reply.structured; + + assert(nbd_reply_is_structured(&reply)); + + switch (chunk->type) { + case NBD_REPLY_TYPE_OFFSET_DATA: + /* + * special cased in nbd_co_receive_one_chunk, data is already + * in qiov + */ + break; + case NBD_REPLY_TYPE_OFFSET_HOLE: + ret = nbd_parse_offset_hole_payload(s, &reply.structured, payload, + offset, qiov, &local_err); + if (ret < 0) { + nbd_channel_error(s, ret); + nbd_iter_channel_error(&iter, ret, &local_err); + } + break; + default: + if (!nbd_reply_type_is_error(chunk->type)) { + /* not allowed reply type */ + nbd_channel_error(s, -EINVAL); + error_setg(&local_err, + "Unexpected reply type: %d (%s) for CMD_READ", + chunk->type, nbd_reply_type_lookup(chunk->type)); + nbd_iter_channel_error(&iter, -EINVAL, &local_err); + } + } + + g_free(payload); + payload = NULL; + } + + error_propagate(errp, iter.err); + *request_ret = iter.request_ret; + return iter.ret; +} + +static int nbd_co_receive_blockstatus_reply(BDRVNBDState *s, + uint64_t handle, uint64_t length, + NBDExtent *extent, + int *request_ret, Error **errp) +{ + NBDReplyChunkIter iter; + NBDReply reply; + void *payload = NULL; + Error *local_err = NULL; + bool received = false; + + assert(!extent->length); + NBD_FOREACH_REPLY_CHUNK(s, iter, handle, false, NULL, &reply, &payload) { + int ret; + NBDStructuredReplyChunk *chunk = &reply.structured; + + assert(nbd_reply_is_structured(&reply)); + + switch (chunk->type) { + case NBD_REPLY_TYPE_BLOCK_STATUS: + if (received) { + nbd_channel_error(s, -EINVAL); + error_setg(&local_err, "Several BLOCK_STATUS chunks in reply"); + nbd_iter_channel_error(&iter, -EINVAL, &local_err); + } + received = true; + + ret = nbd_parse_blockstatus_payload(s, &reply.structured, + payload, length, extent, + &local_err); + if (ret < 0) { + nbd_channel_error(s, ret); + nbd_iter_channel_error(&iter, ret, &local_err); + } + break; + default: + if (!nbd_reply_type_is_error(chunk->type)) { + nbd_channel_error(s, -EINVAL); + error_setg(&local_err, + "Unexpected reply type: %d (%s) " + "for CMD_BLOCK_STATUS", + chunk->type, nbd_reply_type_lookup(chunk->type)); + nbd_iter_channel_error(&iter, -EINVAL, &local_err); + } + } + + g_free(payload); + payload = NULL; + } + + if (!extent->length && !iter.request_ret) { + error_setg(&local_err, "Server did not reply with any status extents"); + nbd_iter_channel_error(&iter, -EIO, &local_err); + } + + error_propagate(errp, iter.err); + *request_ret = iter.request_ret; + return iter.ret; +} + +static int nbd_co_request(BlockDriverState *bs, NBDRequest *request, + QEMUIOVector *write_qiov) +{ + int ret, request_ret; + Error *local_err = NULL; + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; + + assert(request->type != NBD_CMD_READ); + if (write_qiov) { + assert(request->type == NBD_CMD_WRITE); + assert(request->len == iov_size(write_qiov->iov, write_qiov->niov)); + } else { + assert(request->type != NBD_CMD_WRITE); + } + + do { + ret = nbd_co_send_request(bs, request, write_qiov); + if (ret < 0) { + continue; + } + + ret = nbd_co_receive_return_code(s, request->handle, + &request_ret, &local_err); + if (local_err) { + trace_nbd_co_request_fail(request->from, request->len, + request->handle, request->flags, + request->type, + nbd_cmd_lookup(request->type), + ret, error_get_pretty(local_err)); + error_free(local_err); + local_err = NULL; + } + } while (ret < 0 && nbd_client_connecting_wait(s)); + + return ret ? ret : request_ret; +} + +static int nbd_client_co_preadv(BlockDriverState *bs, int64_t offset, + int64_t bytes, QEMUIOVector *qiov, + BdrvRequestFlags flags) +{ + int ret, request_ret; + Error *local_err = NULL; + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; + NBDRequest request = { + .type = NBD_CMD_READ, + .from = offset, + .len = bytes, + }; + + assert(bytes <= NBD_MAX_BUFFER_SIZE); + assert(!flags); + + if (!bytes) { + return 0; + } + /* + * Work around the fact that the block layer doesn't do + * byte-accurate sizing yet - if the read exceeds the server's + * advertised size because the block layer rounded size up, then + * truncate the request to the server and tail-pad with zero. + */ + if (offset >= s->info.size) { + assert(bytes < BDRV_SECTOR_SIZE); + qemu_iovec_memset(qiov, 0, 0, bytes); + return 0; + } + if (offset + bytes > s->info.size) { + uint64_t slop = offset + bytes - s->info.size; + + assert(slop < BDRV_SECTOR_SIZE); + qemu_iovec_memset(qiov, bytes - slop, 0, slop); + request.len -= slop; + } + + do { + ret = nbd_co_send_request(bs, &request, NULL); + if (ret < 0) { + continue; + } + + ret = nbd_co_receive_cmdread_reply(s, request.handle, offset, qiov, + &request_ret, &local_err); + if (local_err) { + trace_nbd_co_request_fail(request.from, request.len, request.handle, + request.flags, request.type, + nbd_cmd_lookup(request.type), + ret, error_get_pretty(local_err)); + error_free(local_err); + local_err = NULL; + } + } while (ret < 0 && nbd_client_connecting_wait(s)); + + return ret ? ret : request_ret; +} + +static int nbd_client_co_pwritev(BlockDriverState *bs, int64_t offset, + int64_t bytes, QEMUIOVector *qiov, + BdrvRequestFlags flags) +{ + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; + NBDRequest request = { + .type = NBD_CMD_WRITE, + .from = offset, + .len = bytes, + }; + + assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); + if (flags & BDRV_REQ_FUA) { + assert(s->info.flags & NBD_FLAG_SEND_FUA); + request.flags |= NBD_CMD_FLAG_FUA; + } + + assert(bytes <= NBD_MAX_BUFFER_SIZE); + + if (!bytes) { + return 0; + } + return nbd_co_request(bs, &request, qiov); +} + +static int nbd_client_co_pwrite_zeroes(BlockDriverState *bs, int64_t offset, + int64_t bytes, BdrvRequestFlags flags) +{ + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; + NBDRequest request = { + .type = NBD_CMD_WRITE_ZEROES, + .from = offset, + .len = bytes, /* .len is uint32_t actually */ + }; + + assert(bytes <= UINT32_MAX); /* rely on max_pwrite_zeroes */ + + assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); + if (!(s->info.flags & NBD_FLAG_SEND_WRITE_ZEROES)) { + return -ENOTSUP; + } + + if (flags & BDRV_REQ_FUA) { + assert(s->info.flags & NBD_FLAG_SEND_FUA); + request.flags |= NBD_CMD_FLAG_FUA; + } + if (!(flags & BDRV_REQ_MAY_UNMAP)) { + request.flags |= NBD_CMD_FLAG_NO_HOLE; + } + if (flags & BDRV_REQ_NO_FALLBACK) { + assert(s->info.flags & NBD_FLAG_SEND_FAST_ZERO); + request.flags |= NBD_CMD_FLAG_FAST_ZERO; + } + + if (!bytes) { + return 0; + } + return nbd_co_request(bs, &request, NULL); +} + +static int nbd_client_co_flush(BlockDriverState *bs) +{ + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; + NBDRequest request = { .type = NBD_CMD_FLUSH }; + + if (!(s->info.flags & NBD_FLAG_SEND_FLUSH)) { + return 0; + } + + request.from = 0; + request.len = 0; + + return nbd_co_request(bs, &request, NULL); +} + +static int nbd_client_co_pdiscard(BlockDriverState *bs, int64_t offset, + int64_t bytes) +{ + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; + NBDRequest request = { + .type = NBD_CMD_TRIM, + .from = offset, + .len = bytes, /* len is uint32_t */ + }; + + assert(bytes <= UINT32_MAX); /* rely on max_pdiscard */ + + assert(!(s->info.flags & NBD_FLAG_READ_ONLY)); + if (!(s->info.flags & NBD_FLAG_SEND_TRIM) || !bytes) { + return 0; + } + + return nbd_co_request(bs, &request, NULL); +} + +static int coroutine_fn nbd_client_co_block_status( + BlockDriverState *bs, bool want_zero, int64_t offset, int64_t bytes, + int64_t *pnum, int64_t *map, BlockDriverState **file) +{ + int ret, request_ret; + NBDExtent extent = { 0 }; + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; + Error *local_err = NULL; + + NBDRequest request = { + .type = NBD_CMD_BLOCK_STATUS, + .from = offset, + .len = MIN(QEMU_ALIGN_DOWN(INT_MAX, bs->bl.request_alignment), + MIN(bytes, s->info.size - offset)), + .flags = NBD_CMD_FLAG_REQ_ONE, + }; + + if (!s->info.base_allocation) { + *pnum = bytes; + *map = offset; + *file = bs; + return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID; + } + + /* + * Work around the fact that the block layer doesn't do + * byte-accurate sizing yet - if the status request exceeds the + * server's advertised size because the block layer rounded size + * up, we truncated the request to the server (above), or are + * called on just the hole. + */ + if (offset >= s->info.size) { + *pnum = bytes; + assert(bytes < BDRV_SECTOR_SIZE); + /* Intentionally don't report offset_valid for the hole */ + return BDRV_BLOCK_ZERO; + } + + if (s->info.min_block) { + assert(QEMU_IS_ALIGNED(request.len, s->info.min_block)); + } + do { + ret = nbd_co_send_request(bs, &request, NULL); + if (ret < 0) { + continue; + } + + ret = nbd_co_receive_blockstatus_reply(s, request.handle, bytes, + &extent, &request_ret, + &local_err); + if (local_err) { + trace_nbd_co_request_fail(request.from, request.len, request.handle, + request.flags, request.type, + nbd_cmd_lookup(request.type), + ret, error_get_pretty(local_err)); + error_free(local_err); + local_err = NULL; + } + } while (ret < 0 && nbd_client_connecting_wait(s)); + + if (ret < 0 || request_ret < 0) { + return ret ? ret : request_ret; + } + + assert(extent.length); + *pnum = extent.length; + *map = offset; + *file = bs; + return (extent.flags & NBD_STATE_HOLE ? 0 : BDRV_BLOCK_DATA) | + (extent.flags & NBD_STATE_ZERO ? BDRV_BLOCK_ZERO : 0) | + BDRV_BLOCK_OFFSET_VALID; +} + +static int nbd_client_reopen_prepare(BDRVReopenState *state, + BlockReopenQueue *queue, Error **errp) +{ + BDRVNBDState *s = (BDRVNBDState *)state->bs->opaque; + + if ((state->flags & BDRV_O_RDWR) && (s->info.flags & NBD_FLAG_READ_ONLY)) { + error_setg(errp, "Can't reopen read-only NBD mount as read/write"); + return -EACCES; + } + return 0; +} + +static void nbd_yank(void *opaque) +{ + BlockDriverState *bs = opaque; + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; + + qatomic_store_release(&s->state, NBD_CLIENT_QUIT); + qio_channel_shutdown(QIO_CHANNEL(s->ioc), QIO_CHANNEL_SHUTDOWN_BOTH, NULL); +} + +static void nbd_client_close(BlockDriverState *bs) +{ + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; + NBDRequest request = { .type = NBD_CMD_DISC }; + + if (s->ioc) { + nbd_send_request(s->ioc, &request); + } + + nbd_teardown_connection(bs); +} + + +/* + * Parse nbd_open options + */ + +static int nbd_parse_uri(const char *filename, QDict *options) +{ + URI *uri; + const char *p; + QueryParams *qp = NULL; + int ret = 0; + bool is_unix; + + uri = uri_parse(filename); + if (!uri) { + return -EINVAL; + } + + /* transport */ + if (!g_strcmp0(uri->scheme, "nbd")) { + is_unix = false; + } else if (!g_strcmp0(uri->scheme, "nbd+tcp")) { + is_unix = false; + } else if (!g_strcmp0(uri->scheme, "nbd+unix")) { + is_unix = true; + } else { + ret = -EINVAL; + goto out; + } + + p = uri->path ? uri->path : ""; + if (p[0] == '/') { + p++; + } + if (p[0]) { + qdict_put_str(options, "export", p); + } + + qp = query_params_parse(uri->query); + if (qp->n > 1 || (is_unix && !qp->n) || (!is_unix && qp->n)) { + ret = -EINVAL; + goto out; + } + + if (is_unix) { + /* nbd+unix:///export?socket=path */ + if (uri->server || uri->port || strcmp(qp->p[0].name, "socket")) { + ret = -EINVAL; + goto out; + } + qdict_put_str(options, "server.type", "unix"); + qdict_put_str(options, "server.path", qp->p[0].value); + } else { + QString *host; + char *port_str; + + /* nbd[+tcp]://host[:port]/export */ + if (!uri->server) { + ret = -EINVAL; + goto out; + } + + /* strip braces from literal IPv6 address */ + if (uri->server[0] == '[') { + host = qstring_from_substr(uri->server, 1, + strlen(uri->server) - 1); + } else { + host = qstring_from_str(uri->server); + } + + qdict_put_str(options, "server.type", "inet"); + qdict_put(options, "server.host", host); + + port_str = g_strdup_printf("%d", uri->port ?: NBD_DEFAULT_PORT); + qdict_put_str(options, "server.port", port_str); + g_free(port_str); + } + +out: + if (qp) { + query_params_free(qp); + } + uri_free(uri); + return ret; +} + +static bool nbd_has_filename_options_conflict(QDict *options, Error **errp) +{ + const QDictEntry *e; + + for (e = qdict_first(options); e; e = qdict_next(options, e)) { + if (!strcmp(e->key, "host") || + !strcmp(e->key, "port") || + !strcmp(e->key, "path") || + !strcmp(e->key, "export") || + strstart(e->key, "server.", NULL)) + { + error_setg(errp, "Option '%s' cannot be used with a file name", + e->key); + return true; + } + } + + return false; +} + +static void nbd_parse_filename(const char *filename, QDict *options, + Error **errp) +{ + g_autofree char *file = NULL; + char *export_name; + const char *host_spec; + const char *unixpath; + + if (nbd_has_filename_options_conflict(options, errp)) { + return; + } + + if (strstr(filename, "://")) { + int ret = nbd_parse_uri(filename, options); + if (ret < 0) { + error_setg(errp, "No valid URL specified"); + } + return; + } + + file = g_strdup(filename); + + export_name = strstr(file, EN_OPTSTR); + if (export_name) { + if (export_name[strlen(EN_OPTSTR)] == 0) { + return; + } + export_name[0] = 0; /* truncate 'file' */ + export_name += strlen(EN_OPTSTR); + + qdict_put_str(options, "export", export_name); + } + + /* extract the host_spec - fail if it's not nbd:... */ + if (!strstart(file, "nbd:", &host_spec)) { + error_setg(errp, "File name string for NBD must start with 'nbd:'"); + return; + } + + if (!*host_spec) { + return; + } + + /* are we a UNIX or TCP socket? */ + if (strstart(host_spec, "unix:", &unixpath)) { + qdict_put_str(options, "server.type", "unix"); + qdict_put_str(options, "server.path", unixpath); + } else { + InetSocketAddress *addr = g_new(InetSocketAddress, 1); + + if (inet_parse(addr, host_spec, errp)) { + goto out_inet; + } + + qdict_put_str(options, "server.type", "inet"); + qdict_put_str(options, "server.host", addr->host); + qdict_put_str(options, "server.port", addr->port); + out_inet: + qapi_free_InetSocketAddress(addr); + } +} + +static bool nbd_process_legacy_socket_options(QDict *output_options, + QemuOpts *legacy_opts, + Error **errp) +{ + const char *path = qemu_opt_get(legacy_opts, "path"); + const char *host = qemu_opt_get(legacy_opts, "host"); + const char *port = qemu_opt_get(legacy_opts, "port"); + const QDictEntry *e; + + if (!path && !host && !port) { + return true; + } + + for (e = qdict_first(output_options); e; e = qdict_next(output_options, e)) + { + if (strstart(e->key, "server.", NULL)) { + error_setg(errp, "Cannot use 'server' and path/host/port at the " + "same time"); + return false; + } + } + + if (path && host) { + error_setg(errp, "path and host may not be used at the same time"); + return false; + } else if (path) { + if (port) { + error_setg(errp, "port may not be used without host"); + return false; + } + + qdict_put_str(output_options, "server.type", "unix"); + qdict_put_str(output_options, "server.path", path); + } else if (host) { + qdict_put_str(output_options, "server.type", "inet"); + qdict_put_str(output_options, "server.host", host); + qdict_put_str(output_options, "server.port", + port ?: stringify(NBD_DEFAULT_PORT)); + } + + return true; +} + +static SocketAddress *nbd_config(BDRVNBDState *s, QDict *options, + Error **errp) +{ + SocketAddress *saddr = NULL; + QDict *addr = NULL; + Visitor *iv = NULL; + + qdict_extract_subqdict(options, &addr, "server."); + if (!qdict_size(addr)) { + error_setg(errp, "NBD server address missing"); + goto done; + } + + iv = qobject_input_visitor_new_flat_confused(addr, errp); + if (!iv) { + goto done; + } + + if (!visit_type_SocketAddress(iv, NULL, &saddr, errp)) { + goto done; + } + + if (socket_address_parse_named_fd(saddr, errp) < 0) { + qapi_free_SocketAddress(saddr); + saddr = NULL; + goto done; + } + +done: + qobject_unref(addr); + visit_free(iv); + return saddr; +} + +static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp) +{ + Object *obj; + QCryptoTLSCreds *creds; + + obj = object_resolve_path_component( + object_get_objects_root(), id); + if (!obj) { + error_setg(errp, "No TLS credentials with id '%s'", + id); + return NULL; + } + creds = (QCryptoTLSCreds *) + object_dynamic_cast(obj, TYPE_QCRYPTO_TLS_CREDS); + if (!creds) { + error_setg(errp, "Object with id '%s' is not TLS credentials", + id); + return NULL; + } + + if (!qcrypto_tls_creds_check_endpoint(creds, + QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT, + errp)) { + return NULL; + } + object_ref(obj); + return creds; +} + + +static QemuOptsList nbd_runtime_opts = { + .name = "nbd", + .head = QTAILQ_HEAD_INITIALIZER(nbd_runtime_opts.head), + .desc = { + { + .name = "host", + .type = QEMU_OPT_STRING, + .help = "TCP host to connect to", + }, + { + .name = "port", + .type = QEMU_OPT_STRING, + .help = "TCP port to connect to", + }, + { + .name = "path", + .type = QEMU_OPT_STRING, + .help = "Unix socket path to connect to", + }, + { + .name = "export", + .type = QEMU_OPT_STRING, + .help = "Name of the NBD export to open", + }, + { + .name = "tls-creds", + .type = QEMU_OPT_STRING, + .help = "ID of the TLS credentials to use", + }, + { + .name = "x-dirty-bitmap", + .type = QEMU_OPT_STRING, + .help = "experimental: expose named dirty bitmap in place of " + "block status", + }, + { + .name = "reconnect-delay", + .type = QEMU_OPT_NUMBER, + .help = "On an unexpected disconnect, the nbd client tries to " + "connect again until succeeding or encountering a serious " + "error. During the first @reconnect-delay seconds, all " + "requests are paused and will be rerun on a successful " + "reconnect. After that time, any delayed requests and all " + "future requests before a successful reconnect will " + "immediately fail. Default 0", + }, + { /* end of list */ } + }, +}; + +static int nbd_process_options(BlockDriverState *bs, QDict *options, + Error **errp) +{ + BDRVNBDState *s = bs->opaque; + QemuOpts *opts; + int ret = -EINVAL; + + opts = qemu_opts_create(&nbd_runtime_opts, NULL, 0, &error_abort); + if (!qemu_opts_absorb_qdict(opts, options, errp)) { + goto error; + } + + /* Translate @host, @port, and @path to a SocketAddress */ + if (!nbd_process_legacy_socket_options(options, opts, errp)) { + goto error; + } + + /* Pop the config into our state object. Exit if invalid. */ + s->saddr = nbd_config(s, options, errp); + if (!s->saddr) { + goto error; + } + + s->export = g_strdup(qemu_opt_get(opts, "export")); + if (s->export && strlen(s->export) > NBD_MAX_STRING_SIZE) { + error_setg(errp, "export name too long to send to server"); + goto error; + } + + s->tlscredsid = g_strdup(qemu_opt_get(opts, "tls-creds")); + if (s->tlscredsid) { + s->tlscreds = nbd_get_tls_creds(s->tlscredsid, errp); + if (!s->tlscreds) { + goto error; + } + + /* TODO SOCKET_ADDRESS_KIND_FD where fd has AF_INET or AF_INET6 */ + if (s->saddr->type != SOCKET_ADDRESS_TYPE_INET) { + error_setg(errp, "TLS only supported over IP sockets"); + goto error; + } + s->hostname = s->saddr->u.inet.host; + } + + s->x_dirty_bitmap = g_strdup(qemu_opt_get(opts, "x-dirty-bitmap")); + if (s->x_dirty_bitmap && strlen(s->x_dirty_bitmap) > NBD_MAX_STRING_SIZE) { + error_setg(errp, "x-dirty-bitmap query too long to send to server"); + goto error; + } + + s->reconnect_delay = qemu_opt_get_number(opts, "reconnect-delay", 0); + + ret = 0; + + error: + qemu_opts_del(opts); + return ret; +} + +static int nbd_open(BlockDriverState *bs, QDict *options, int flags, + Error **errp) +{ + int ret; + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; + + s->bs = bs; + qemu_co_mutex_init(&s->send_mutex); + qemu_co_queue_init(&s->free_sema); + qemu_co_mutex_init(&s->receive_mutex); + + if (!yank_register_instance(BLOCKDEV_YANK_INSTANCE(bs->node_name), errp)) { + return -EEXIST; + } + + ret = nbd_process_options(bs, options, errp); + if (ret < 0) { + goto fail; + } + + s->conn = nbd_client_connection_new(s->saddr, true, s->export, + s->x_dirty_bitmap, s->tlscreds); + + /* TODO: Configurable retry-until-timeout behaviour. */ + s->state = NBD_CLIENT_CONNECTING_WAIT; + ret = nbd_do_establish_connection(bs, errp); + if (ret < 0) { + goto fail; + } + + nbd_client_connection_enable_retry(s->conn); + + return 0; + +fail: + nbd_clear_bdrvstate(bs); + return ret; +} + +static int nbd_co_flush(BlockDriverState *bs) +{ + return nbd_client_co_flush(bs); +} + +static void nbd_refresh_limits(BlockDriverState *bs, Error **errp) +{ + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; + uint32_t min = s->info.min_block; + uint32_t max = MIN_NON_ZERO(NBD_MAX_BUFFER_SIZE, s->info.max_block); + + /* + * If the server did not advertise an alignment: + * - a size that is not sector-aligned implies that an alignment + * of 1 can be used to access those tail bytes + * - advertisement of block status requires an alignment of 1, so + * that we don't violate block layer constraints that block + * status is always aligned (as we can't control whether the + * server will report sub-sector extents, such as a hole at EOF + * on an unaligned POSIX file) + * - otherwise, assume the server is so old that we are safer avoiding + * sub-sector requests + */ + if (!min) { + min = (!QEMU_IS_ALIGNED(s->info.size, BDRV_SECTOR_SIZE) || + s->info.base_allocation) ? 1 : BDRV_SECTOR_SIZE; + } + + bs->bl.request_alignment = min; + bs->bl.max_pdiscard = QEMU_ALIGN_DOWN(INT_MAX, min); + bs->bl.max_pwrite_zeroes = max; + bs->bl.max_transfer = max; + + if (s->info.opt_block && + s->info.opt_block > bs->bl.opt_transfer) { + bs->bl.opt_transfer = s->info.opt_block; + } +} + +static void nbd_close(BlockDriverState *bs) +{ + nbd_client_close(bs); + nbd_clear_bdrvstate(bs); +} + +/* + * NBD cannot truncate, but if the caller asks to truncate to the same size, or + * to a smaller size with exact=false, there is no reason to fail the + * operation. + * + * Preallocation mode is ignored since it does not seems useful to fail when + * we never change anything. + */ +static int coroutine_fn nbd_co_truncate(BlockDriverState *bs, int64_t offset, + bool exact, PreallocMode prealloc, + BdrvRequestFlags flags, Error **errp) +{ + BDRVNBDState *s = bs->opaque; + + if (offset != s->info.size && exact) { + error_setg(errp, "Cannot resize NBD nodes"); + return -ENOTSUP; + } + + if (offset > s->info.size) { + error_setg(errp, "Cannot grow NBD nodes"); + return -EINVAL; + } + + return 0; +} + +static int64_t nbd_getlength(BlockDriverState *bs) +{ + BDRVNBDState *s = bs->opaque; + + return s->info.size; +} + +static void nbd_refresh_filename(BlockDriverState *bs) +{ + BDRVNBDState *s = bs->opaque; + const char *host = NULL, *port = NULL, *path = NULL; + size_t len = 0; + + if (s->saddr->type == SOCKET_ADDRESS_TYPE_INET) { + const InetSocketAddress *inet = &s->saddr->u.inet; + if (!inet->has_ipv4 && !inet->has_ipv6 && !inet->has_to) { + host = inet->host; + port = inet->port; + } + } else if (s->saddr->type == SOCKET_ADDRESS_TYPE_UNIX) { + path = s->saddr->u.q_unix.path; + } /* else can't represent as pseudo-filename */ + + if (path && s->export) { + len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), + "nbd+unix:///%s?socket=%s", s->export, path); + } else if (path && !s->export) { + len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), + "nbd+unix://?socket=%s", path); + } else if (host && s->export) { + len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), + "nbd://%s:%s/%s", host, port, s->export); + } else if (host && !s->export) { + len = snprintf(bs->exact_filename, sizeof(bs->exact_filename), + "nbd://%s:%s", host, port); + } + if (len >= sizeof(bs->exact_filename)) { + /* Name is too long to represent exactly, so leave it empty. */ + bs->exact_filename[0] = '\0'; + } +} + +static char *nbd_dirname(BlockDriverState *bs, Error **errp) +{ + /* The generic bdrv_dirname() implementation is able to work out some + * directory name for NBD nodes, but that would be wrong. So far there is no + * specification for how "export paths" would work, so NBD does not have + * directory names. */ + error_setg(errp, "Cannot generate a base directory for NBD nodes"); + return NULL; +} + +static const char *const nbd_strong_runtime_opts[] = { + "path", + "host", + "port", + "export", + "tls-creds", + "server.", + + NULL +}; + +static void nbd_cancel_in_flight(BlockDriverState *bs) +{ + BDRVNBDState *s = (BDRVNBDState *)bs->opaque; + + reconnect_delay_timer_del(s); + + if (s->state == NBD_CLIENT_CONNECTING_WAIT) { + s->state = NBD_CLIENT_CONNECTING_NOWAIT; + qemu_co_queue_restart_all(&s->free_sema); + } + + nbd_co_establish_connection_cancel(s->conn); +} + +static BlockDriver bdrv_nbd = { + .format_name = "nbd", + .protocol_name = "nbd", + .instance_size = sizeof(BDRVNBDState), + .bdrv_parse_filename = nbd_parse_filename, + .bdrv_co_create_opts = bdrv_co_create_opts_simple, + .create_opts = &bdrv_create_opts_simple, + .bdrv_file_open = nbd_open, + .bdrv_reopen_prepare = nbd_client_reopen_prepare, + .bdrv_co_preadv = nbd_client_co_preadv, + .bdrv_co_pwritev = nbd_client_co_pwritev, + .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, + .bdrv_close = nbd_close, + .bdrv_co_flush_to_os = nbd_co_flush, + .bdrv_co_pdiscard = nbd_client_co_pdiscard, + .bdrv_refresh_limits = nbd_refresh_limits, + .bdrv_co_truncate = nbd_co_truncate, + .bdrv_getlength = nbd_getlength, + .bdrv_refresh_filename = nbd_refresh_filename, + .bdrv_co_block_status = nbd_client_co_block_status, + .bdrv_dirname = nbd_dirname, + .strong_runtime_opts = nbd_strong_runtime_opts, + .bdrv_cancel_in_flight = nbd_cancel_in_flight, +}; + +static BlockDriver bdrv_nbd_tcp = { + .format_name = "nbd", + .protocol_name = "nbd+tcp", + .instance_size = sizeof(BDRVNBDState), + .bdrv_parse_filename = nbd_parse_filename, + .bdrv_co_create_opts = bdrv_co_create_opts_simple, + .create_opts = &bdrv_create_opts_simple, + .bdrv_file_open = nbd_open, + .bdrv_reopen_prepare = nbd_client_reopen_prepare, + .bdrv_co_preadv = nbd_client_co_preadv, + .bdrv_co_pwritev = nbd_client_co_pwritev, + .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, + .bdrv_close = nbd_close, + .bdrv_co_flush_to_os = nbd_co_flush, + .bdrv_co_pdiscard = nbd_client_co_pdiscard, + .bdrv_refresh_limits = nbd_refresh_limits, + .bdrv_co_truncate = nbd_co_truncate, + .bdrv_getlength = nbd_getlength, + .bdrv_refresh_filename = nbd_refresh_filename, + .bdrv_co_block_status = nbd_client_co_block_status, + .bdrv_dirname = nbd_dirname, + .strong_runtime_opts = nbd_strong_runtime_opts, + .bdrv_cancel_in_flight = nbd_cancel_in_flight, +}; + +static BlockDriver bdrv_nbd_unix = { + .format_name = "nbd", + .protocol_name = "nbd+unix", + .instance_size = sizeof(BDRVNBDState), + .bdrv_parse_filename = nbd_parse_filename, + .bdrv_co_create_opts = bdrv_co_create_opts_simple, + .create_opts = &bdrv_create_opts_simple, + .bdrv_file_open = nbd_open, + .bdrv_reopen_prepare = nbd_client_reopen_prepare, + .bdrv_co_preadv = nbd_client_co_preadv, + .bdrv_co_pwritev = nbd_client_co_pwritev, + .bdrv_co_pwrite_zeroes = nbd_client_co_pwrite_zeroes, + .bdrv_close = nbd_close, + .bdrv_co_flush_to_os = nbd_co_flush, + .bdrv_co_pdiscard = nbd_client_co_pdiscard, + .bdrv_refresh_limits = nbd_refresh_limits, + .bdrv_co_truncate = nbd_co_truncate, + .bdrv_getlength = nbd_getlength, + .bdrv_refresh_filename = nbd_refresh_filename, + .bdrv_co_block_status = nbd_client_co_block_status, + .bdrv_dirname = nbd_dirname, + .strong_runtime_opts = nbd_strong_runtime_opts, + .bdrv_cancel_in_flight = nbd_cancel_in_flight, +}; + +static void bdrv_nbd_init(void) +{ + bdrv_register(&bdrv_nbd); + bdrv_register(&bdrv_nbd_tcp); + bdrv_register(&bdrv_nbd_unix); +} + +block_init(bdrv_nbd_init); -- cgit