int nbd_send_request(QIOChannel *ioc, NBDRequest *request)
{
- uint8_t buf[NBD_REQUEST_SIZE];
+ uint8_t buf[NBD_EXTENDED_REQUEST_SIZE];
+ size_t len;
- assert(request->mode <= NBD_MODE_STRUCTURED); /* TODO handle extended */
- assert(request->len <= UINT32_MAX);
trace_nbd_send_request(request->from, request->len, request->cookie,
request->flags, request->type,
nbd_cmd_lookup(request->type));
- stl_be_p(buf, NBD_REQUEST_MAGIC);
stw_be_p(buf + 4, request->flags);
stw_be_p(buf + 6, request->type);
stq_be_p(buf + 8, request->cookie);
stq_be_p(buf + 16, request->from);
- stl_be_p(buf + 24, request->len);
+ if (request->mode >= NBD_MODE_EXTENDED) {
+ stl_be_p(buf, NBD_EXTENDED_REQUEST_MAGIC);
+ stq_be_p(buf + 24, request->len);
+ len = NBD_EXTENDED_REQUEST_SIZE;
+ } else {
+ assert(request->len <= UINT32_MAX);
+ stl_be_p(buf, NBD_REQUEST_MAGIC);
+ stl_be_p(buf + 24, request->len);
+ len = NBD_REQUEST_SIZE;
+ }
- return nbd_write(ioc, buf, sizeof(buf), NULL);
+ return nbd_write(ioc, buf, len, NULL);
}
/* nbd_receive_simple_reply
return 0;
}
-/* nbd_receive_structured_reply_chunk
+/* nbd_receive_reply_chunk_header
* Read structured reply chunk except magic field (which should be already
- * read).
+ * read). Normalize into the compact form.
* Payload is not read.
*/
-static int nbd_receive_structured_reply_chunk(QIOChannel *ioc,
- NBDStructuredReplyChunk *chunk,
- Error **errp)
+static int nbd_receive_reply_chunk_header(QIOChannel *ioc, NBDReply *chunk,
+ Error **errp)
{
int ret;
+ size_t len;
+ uint64_t payload_len;
- assert(chunk->magic == NBD_STRUCTURED_REPLY_MAGIC);
+ if (chunk->magic == NBD_STRUCTURED_REPLY_MAGIC) {
+ len = sizeof(chunk->structured);
+ } else {
+ assert(chunk->magic == NBD_EXTENDED_REPLY_MAGIC);
+ len = sizeof(chunk->extended);
+ }
ret = nbd_read(ioc, (uint8_t *)chunk + sizeof(chunk->magic),
- sizeof(*chunk) - sizeof(chunk->magic), "structured chunk",
+ len - sizeof(chunk->magic), "structured chunk",
errp);
if (ret < 0) {
return ret;
}
- chunk->flags = be16_to_cpu(chunk->flags);
- chunk->type = be16_to_cpu(chunk->type);
- chunk->cookie = be64_to_cpu(chunk->cookie);
- chunk->length = be32_to_cpu(chunk->length);
+ /* flags, type, and cookie occupy same space between forms */
+ chunk->structured.flags = be16_to_cpu(chunk->structured.flags);
+ chunk->structured.type = be16_to_cpu(chunk->structured.type);
+ chunk->structured.cookie = be64_to_cpu(chunk->structured.cookie);
/*
* Because we use BLOCK_STATUS with REQ_ONE, and cap READ requests
* this. Even if we stopped using REQ_ONE, sane servers will cap
* the number of extents they return for block status.
*/
- if (chunk->length > NBD_MAX_BUFFER_SIZE + sizeof(NBDStructuredReadData)) {
+ if (chunk->magic == NBD_STRUCTURED_REPLY_MAGIC) {
+ payload_len = be32_to_cpu(chunk->structured.length);
+ } else {
+ /* For now, we are ignoring the extended header offset. */
+ payload_len = be64_to_cpu(chunk->extended.length);
+ chunk->magic = NBD_STRUCTURED_REPLY_MAGIC;
+ }
+ if (payload_len > NBD_MAX_BUFFER_SIZE + sizeof(NBDStructuredReadData)) {
error_setg(errp, "server chunk %" PRIu32 " (%s) payload is too long",
- chunk->type, nbd_rep_lookup(chunk->type));
+ chunk->structured.type,
+ nbd_rep_lookup(chunk->structured.type));
return -EINVAL;
}
+ chunk->structured.length = payload_len;
return 0;
}
/* nbd_receive_reply
*
- * Decreases bs->in_flight while waiting for a new reply. This yield is where
- * we wait indefinitely and the coroutine must be able to be safely reentered
- * for nbd_client_attach_aio_context().
+ * Wait for a new reply. If this yields, the coroutine must be able to be
+ * safely reentered for nbd_client_attach_aio_context(). @mode determines
+ * which reply magic we are expecting, although this normalizes the result
+ * so that the caller only has to work with compact headers.
*
* Returns 1 on success
- * 0 on eof, when no data was read (errp is not set)
- * negative errno on failure (errp is set)
+ * 0 on eof, when no data was read
+ * negative errno on failure
*/
int coroutine_fn nbd_receive_reply(BlockDriverState *bs, QIOChannel *ioc,
- NBDReply *reply, Error **errp)
+ NBDReply *reply, NBDMode mode, Error **errp)
{
int ret;
const char *type;
+ uint32_t expected;
ret = nbd_read_eof(bs, ioc, &reply->magic, sizeof(reply->magic), errp);
if (ret <= 0) {
reply->magic = be32_to_cpu(reply->magic);
+ /* Diagnose but accept wrong-width header */
switch (reply->magic) {
case NBD_SIMPLE_REPLY_MAGIC:
+ if (mode >= NBD_MODE_EXTENDED) {
+ trace_nbd_receive_wrong_header(reply->magic,
+ nbd_mode_lookup(mode));
+ }
ret = nbd_receive_simple_reply(ioc, &reply->simple, errp);
if (ret < 0) {
- break;
+ return ret;
}
trace_nbd_receive_simple_reply(reply->simple.error,
nbd_err_lookup(reply->simple.error),
reply->cookie);
break;
case NBD_STRUCTURED_REPLY_MAGIC:
- ret = nbd_receive_structured_reply_chunk(ioc, &reply->structured, errp);
+ case NBD_EXTENDED_REPLY_MAGIC:
+ expected = mode >= NBD_MODE_EXTENDED ? NBD_EXTENDED_REPLY_MAGIC
+ : NBD_STRUCTURED_REPLY_MAGIC;
+ if (reply->magic != expected) {
+ trace_nbd_receive_wrong_header(reply->magic,
+ nbd_mode_lookup(mode));
+ }
+ ret = nbd_receive_reply_chunk_header(ioc, reply, errp);
if (ret < 0) {
- break;
+ return ret;
}
type = nbd_reply_type_lookup(reply->structured.type);
- trace_nbd_receive_structured_reply_chunk(reply->structured.flags,
- reply->structured.type, type,
- reply->structured.cookie,
- reply->structured.length);
+ trace_nbd_receive_reply_chunk_header(reply->structured.flags,
+ reply->structured.type, type,
+ reply->structured.cookie,
+ reply->structured.length);
break;
default:
+ trace_nbd_receive_wrong_header(reply->magic, nbd_mode_lookup(mode));
error_setg(errp, "invalid magic (got 0x%" PRIx32 ")", reply->magic);
return -EINVAL;
}
- if (ret < 0) {
- return ret;
- }
return 1;
}
projects / thirdparty / qemu.git / blobdiff