#include "qapi/error.h"
#include "trace.h"
#include "nbd-internal.h"
+#include "qemu/cutils.h"
/* Definitions for opaque data types */
NBDOptionReply *reply, Error **errp)
{
QEMU_BUILD_BUG_ON(sizeof(*reply) != 20);
- if (nbd_read(ioc, reply, sizeof(*reply), errp) < 0) {
- error_prepend(errp, "failed to read option reply: ");
+ if (nbd_read(ioc, reply, sizeof(*reply), "option reply", errp) < 0) {
nbd_send_opt_abort(ioc);
return -1;
}
goto cleanup;
}
msg = g_malloc(reply->length + 1);
- if (nbd_read(ioc, msg, reply->length, errp) < 0) {
- error_prepend(errp, "failed to read option error %" PRIu32
+ if (nbd_read(ioc, msg, reply->length, NULL, errp) < 0) {
+ error_prepend(errp, "Failed to read option error %" PRIu32
" (%s) message: ",
reply->type, nbd_rep_lookup(reply->type));
goto cleanup;
nbd_send_opt_abort(ioc);
return -1;
}
- if (nbd_read(ioc, &namelen, sizeof(namelen), errp) < 0) {
- error_prepend(errp, "failed to read option name length: ");
+ if (nbd_read32(ioc, &namelen, "option name length", errp) < 0) {
nbd_send_opt_abort(ioc);
return -1;
}
- namelen = be32_to_cpu(namelen);
len -= sizeof(namelen);
if (len < namelen) {
error_setg(errp, "incorrect option name length");
}
local_name = g_malloc(namelen + 1);
- if (nbd_read(ioc, local_name, namelen, errp) < 0) {
- error_prepend(errp, "failed to read export name: ");
+ if (nbd_read(ioc, local_name, namelen, "export name", errp) < 0) {
nbd_send_opt_abort(ioc);
goto out;
}
len -= namelen;
if (len) {
local_desc = g_malloc(len + 1);
- if (nbd_read(ioc, local_desc, len, errp) < 0) {
- error_prepend(errp, "failed to read export description: ");
+ if (nbd_read(ioc, local_desc, len, "export description", errp) < 0) {
nbd_send_opt_abort(ioc);
goto out;
}
}
-/* Returns -1 if NBD_OPT_GO proves the export @info->name cannot be
- * used, 0 if NBD_OPT_GO is unsupported (fall back to NBD_OPT_LIST and
+/*
+ * nbd_opt_info_or_go:
+ * Send option for NBD_OPT_INFO or NBD_OPT_GO and parse the reply.
+ * Returns -1 if the option proves the export @info->name cannot be
+ * used, 0 if the option is unsupported (fall back to NBD_OPT_LIST and
* NBD_OPT_EXPORT_NAME in that case), and > 0 if the export is good to
- * go (with the rest of @info populated). */
-static int nbd_opt_go(QIOChannel *ioc, NBDExportInfo *info, Error **errp)
+ * go (with the rest of @info populated).
+ */
+static int nbd_opt_info_or_go(QIOChannel *ioc, uint32_t opt,
+ NBDExportInfo *info, Error **errp)
{
NBDOptionReply reply;
uint32_t len = strlen(info->name);
* flags still 0 is a witness of a broken server. */
info->flags = 0;
- trace_nbd_opt_go_start(info->name);
+ assert(opt == NBD_OPT_GO || opt == NBD_OPT_INFO);
+ trace_nbd_opt_info_go_start(nbd_opt_lookup(opt), info->name);
buf = g_malloc(4 + len + 2 + 2 * info->request_sizes + 1);
stl_be_p(buf, len);
memcpy(buf + 4, info->name, len);
if (info->request_sizes) {
stw_be_p(buf + 4 + len + 2, NBD_INFO_BLOCK_SIZE);
}
- error = nbd_send_option_request(ioc, NBD_OPT_GO,
+ error = nbd_send_option_request(ioc, opt,
4 + len + 2 + 2 * info->request_sizes,
buf, errp);
g_free(buf);
}
while (1) {
- if (nbd_receive_option_reply(ioc, NBD_OPT_GO, &reply, errp) < 0) {
+ if (nbd_receive_option_reply(ioc, opt, &reply, errp) < 0) {
return -1;
}
error = nbd_handle_reply_err(ioc, &reply, errp);
len = reply.length;
if (reply.type == NBD_REP_ACK) {
- /* Server is done sending info and moved into transmission
- phase, but make sure it sent flags */
+ /*
+ * Server is done sending info, and moved into transmission
+ * phase for NBD_OPT_GO, but make sure it sent flags
+ */
if (len) {
error_setg(errp, "server sent invalid NBD_REP_ACK");
return -1;
error_setg(errp, "broken server omitted NBD_INFO_EXPORT");
return -1;
}
- trace_nbd_opt_go_success();
+ trace_nbd_opt_info_go_success(nbd_opt_lookup(opt));
return 1;
}
if (reply.type != NBD_REP_INFO) {
nbd_send_opt_abort(ioc);
return -1;
}
- if (nbd_read(ioc, &type, sizeof(type), errp) < 0) {
- error_prepend(errp, "failed to read info type: ");
+ if (nbd_read16(ioc, &type, "info type", errp) < 0) {
nbd_send_opt_abort(ioc);
return -1;
}
len -= sizeof(type);
- type = be16_to_cpu(type);
switch (type) {
case NBD_INFO_EXPORT:
if (len != sizeof(info->size) + sizeof(info->flags)) {
nbd_send_opt_abort(ioc);
return -1;
}
- if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) {
- error_prepend(errp, "failed to read info size: ");
+ if (nbd_read64(ioc, &info->size, "info size", errp) < 0) {
nbd_send_opt_abort(ioc);
return -1;
}
- info->size = be64_to_cpu(info->size);
- if (nbd_read(ioc, &info->flags, sizeof(info->flags), errp) < 0) {
- error_prepend(errp, "failed to read info flags: ");
+ if (nbd_read16(ioc, &info->flags, "info flags", errp) < 0) {
nbd_send_opt_abort(ioc);
return -1;
}
- info->flags = be16_to_cpu(info->flags);
trace_nbd_receive_negotiate_size_flags(info->size, info->flags);
break;
nbd_send_opt_abort(ioc);
return -1;
}
- if (nbd_read(ioc, &info->min_block, sizeof(info->min_block),
- errp) < 0) {
- error_prepend(errp, "failed to read info minimum block size: ");
+ if (nbd_read32(ioc, &info->min_block, "info minimum block size",
+ errp) < 0) {
nbd_send_opt_abort(ioc);
return -1;
}
- info->min_block = be32_to_cpu(info->min_block);
if (!is_power_of_2(info->min_block)) {
error_setg(errp, "server minimum block size %" PRIu32
" is not a power of two", info->min_block);
nbd_send_opt_abort(ioc);
return -1;
}
- if (nbd_read(ioc, &info->opt_block, sizeof(info->opt_block),
- errp) < 0) {
- error_prepend(errp,
- "failed to read info preferred block size: ");
+ if (nbd_read32(ioc, &info->opt_block, "info preferred block size",
+ errp) < 0)
+ {
nbd_send_opt_abort(ioc);
return -1;
}
- info->opt_block = be32_to_cpu(info->opt_block);
if (!is_power_of_2(info->opt_block) ||
info->opt_block < info->min_block) {
error_setg(errp, "server preferred block size %" PRIu32
nbd_send_opt_abort(ioc);
return -1;
}
- if (nbd_read(ioc, &info->max_block, sizeof(info->max_block),
- errp) < 0) {
- error_prepend(errp, "failed to read info maximum block size: ");
+ if (nbd_read32(ioc, &info->max_block, "info maximum block size",
+ errp) < 0)
+ {
nbd_send_opt_abort(ioc);
return -1;
}
- info->max_block = be32_to_cpu(info->max_block);
if (info->max_block < info->min_block) {
error_setg(errp, "server maximum block size %" PRIu32
" is not valid", info->max_block);
nbd_send_opt_abort(ioc);
return -1;
}
- trace_nbd_opt_go_info_block_size(info->min_block, info->opt_block,
- info->max_block);
+ trace_nbd_opt_info_block_size(info->min_block, info->opt_block,
+ info->max_block);
break;
default:
- trace_nbd_opt_go_info_unknown(type, nbd_info_lookup(type));
+ trace_nbd_opt_info_unknown(type, nbd_info_lookup(type));
if (nbd_drop(ioc, len, errp) < 0) {
error_prepend(errp, "Failed to read info payload: ");
nbd_send_opt_abort(ioc);
return QIO_CHANNEL(tioc);
}
-/* nbd_negotiate_simple_meta_context:
+/*
+ * nbd_send_meta_query:
+ * Send 0 or 1 set/list meta context queries.
+ * Return 0 on success, -1 with errp set for any error
+ */
+static int nbd_send_meta_query(QIOChannel *ioc, uint32_t opt,
+ const char *export, const char *query,
+ Error **errp)
+{
+ int ret;
+ uint32_t export_len = strlen(export);
+ uint32_t queries = !!query;
+ uint32_t query_len = 0;
+ uint32_t data_len;
+ char *data;
+ char *p;
+
+ data_len = sizeof(export_len) + export_len + sizeof(queries);
+ if (query) {
+ query_len = strlen(query);
+ data_len += sizeof(query_len) + query_len;
+ } else {
+ assert(opt == NBD_OPT_LIST_META_CONTEXT);
+ }
+ p = data = g_malloc(data_len);
+
+ trace_nbd_opt_meta_request(nbd_opt_lookup(opt), query ?: "(all)", export);
+ stl_be_p(p, export_len);
+ memcpy(p += sizeof(export_len), export, export_len);
+ stl_be_p(p += export_len, queries);
+ if (query) {
+ stl_be_p(p += sizeof(queries), query_len);
+ memcpy(p += sizeof(query_len), query, query_len);
+ }
+
+ ret = nbd_send_option_request(ioc, opt, data_len, data, errp);
+ g_free(data);
+ return ret;
+}
+
+/*
+ * nbd_receive_one_meta_context:
+ * Called in a loop to receive and trace one set/list meta context reply.
+ * Pass non-NULL @name or @id to collect results back to the caller, which
+ * must eventually call g_free().
+ * return 1 if name is set and iteration must continue,
+ * 0 if iteration is complete (including if option is unsupported),
+ * -1 with errp set for any error
+ */
+static int nbd_receive_one_meta_context(QIOChannel *ioc,
+ uint32_t opt,
+ char **name,
+ uint32_t *id,
+ Error **errp)
+{
+ int ret;
+ NBDOptionReply reply;
+ char *local_name = NULL;
+ uint32_t local_id;
+
+ if (nbd_receive_option_reply(ioc, opt, &reply, errp) < 0) {
+ return -1;
+ }
+
+ ret = nbd_handle_reply_err(ioc, &reply, errp);
+ if (ret <= 0) {
+ return ret;
+ }
+
+ if (reply.type == NBD_REP_ACK) {
+ if (reply.length != 0) {
+ error_setg(errp, "Unexpected length to ACK response");
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ return 0;
+ } else if (reply.type != NBD_REP_META_CONTEXT) {
+ error_setg(errp, "Unexpected reply type %u (%s), expected %u (%s)",
+ reply.type, nbd_rep_lookup(reply.type),
+ NBD_REP_META_CONTEXT, nbd_rep_lookup(NBD_REP_META_CONTEXT));
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+
+ if (reply.length <= sizeof(local_id) ||
+ reply.length > NBD_MAX_BUFFER_SIZE) {
+ error_setg(errp, "Failed to negotiate meta context, server "
+ "answered with unexpected length %" PRIu32,
+ reply.length);
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+
+ if (nbd_read32(ioc, &local_id, "context id", errp) < 0) {
+ return -1;
+ }
+
+ reply.length -= sizeof(local_id);
+ local_name = g_malloc(reply.length + 1);
+ if (nbd_read(ioc, local_name, reply.length, "context name", errp) < 0) {
+ g_free(local_name);
+ return -1;
+ }
+ local_name[reply.length] = '\0';
+ trace_nbd_opt_meta_reply(nbd_opt_lookup(opt), local_name, local_id);
+
+ if (name) {
+ *name = local_name;
+ } else {
+ g_free(local_name);
+ }
+ if (id) {
+ *id = local_id;
+ }
+ return 1;
+}
+
+/*
+ * nbd_negotiate_simple_meta_context:
* Request the server to set the meta context for export @info->name
* using @info->x_dirty_bitmap with a fallback to "base:allocation",
* setting @info->context_id to the resulting id. Fail if the server
* function should lose the term _simple.
*/
int ret;
- NBDOptionReply reply;
const char *context = info->x_dirty_bitmap ?: "base:allocation";
bool received = false;
- uint32_t export_len = strlen(info->name);
- uint32_t context_len = strlen(context);
- uint32_t data_len = sizeof(export_len) + export_len +
- sizeof(uint32_t) + /* number of queries */
- sizeof(context_len) + context_len;
- char *data = g_malloc(data_len);
- char *p = data;
-
- trace_nbd_opt_meta_request(context, info->name);
- stl_be_p(p, export_len);
- memcpy(p += sizeof(export_len), info->name, export_len);
- stl_be_p(p += export_len, 1);
- stl_be_p(p += sizeof(uint32_t), context_len);
- memcpy(p += sizeof(context_len), context, context_len);
+ char *name = NULL;
- ret = nbd_send_option_request(ioc, NBD_OPT_SET_META_CONTEXT, data_len, data,
- errp);
- g_free(data);
- if (ret < 0) {
- return ret;
- }
-
- if (nbd_receive_option_reply(ioc, NBD_OPT_SET_META_CONTEXT, &reply,
- errp) < 0)
- {
+ if (nbd_send_meta_query(ioc, NBD_OPT_SET_META_CONTEXT,
+ info->name, context, errp) < 0) {
return -1;
}
- ret = nbd_handle_reply_err(ioc, &reply, errp);
- if (ret <= 0) {
- return ret;
+ ret = nbd_receive_one_meta_context(ioc, NBD_OPT_SET_META_CONTEXT,
+ &name, &info->context_id, errp);
+ if (ret < 0) {
+ return -1;
}
-
- if (reply.type == NBD_REP_META_CONTEXT) {
- char *name;
-
- if (reply.length != sizeof(info->context_id) + context_len) {
- error_setg(errp, "Failed to negotiate meta context '%s', server "
- "answered with unexpected length %" PRIu32, context,
- reply.length);
- nbd_send_opt_abort(ioc);
- return -1;
- }
-
- if (nbd_read(ioc, &info->context_id, sizeof(info->context_id),
- errp) < 0) {
- return -1;
- }
- info->context_id = be32_to_cpu(info->context_id);
-
- reply.length -= sizeof(info->context_id);
- name = g_malloc(reply.length + 1);
- if (nbd_read(ioc, name, reply.length, errp) < 0) {
- g_free(name);
- return -1;
- }
- name[reply.length] = '\0';
+ if (ret == 1) {
if (strcmp(context, name)) {
error_setg(errp, "Failed to negotiate meta context '%s', server "
"answered with different context '%s'", context,
return -1;
}
g_free(name);
-
- trace_nbd_opt_meta_reply(context, info->context_id);
received = true;
- /* receive NBD_REP_ACK */
- if (nbd_receive_option_reply(ioc, NBD_OPT_SET_META_CONTEXT, &reply,
- errp) < 0)
- {
+ ret = nbd_receive_one_meta_context(ioc, NBD_OPT_SET_META_CONTEXT,
+ NULL, NULL, errp);
+ if (ret < 0) {
return -1;
}
-
- ret = nbd_handle_reply_err(ioc, &reply, errp);
- if (ret <= 0) {
- return ret;
- }
}
-
- if (reply.type != NBD_REP_ACK) {
- error_setg(errp, "Unexpected reply type %u (%s), expected %u (%s)",
- reply.type, nbd_rep_lookup(reply.type),
- NBD_REP_ACK, nbd_rep_lookup(NBD_REP_ACK));
+ if (ret != 0) {
+ error_setg(errp, "Server answered with more than one context");
nbd_send_opt_abort(ioc);
return -1;
}
- if (reply.length) {
- error_setg(errp, "Unexpected length to ACK response");
- nbd_send_opt_abort(ioc);
+ return received;
+}
+
+/*
+ * nbd_list_meta_contexts:
+ * Request the server to list all meta contexts for export @info->name.
+ * return 0 if list is complete (even if empty),
+ * -1 with errp set for any error
+ */
+static int nbd_list_meta_contexts(QIOChannel *ioc,
+ NBDExportInfo *info,
+ Error **errp)
+{
+ int ret;
+ int seen_any = false;
+ int seen_qemu = false;
+
+ if (nbd_send_meta_query(ioc, NBD_OPT_LIST_META_CONTEXT,
+ info->name, NULL, errp) < 0) {
return -1;
}
- return received;
+ while (1) {
+ char *context;
+
+ ret = nbd_receive_one_meta_context(ioc, NBD_OPT_LIST_META_CONTEXT,
+ &context, NULL, errp);
+ if (ret == 0 && seen_any && !seen_qemu) {
+ /*
+ * Work around qemu 3.0 bug: the server forgot to send
+ * "qemu:" replies to 0 queries. If we saw at least one
+ * reply (probably base:allocation), but none of them were
+ * qemu:, then run a more specific query to make sure.
+ */
+ seen_qemu = true;
+ if (nbd_send_meta_query(ioc, NBD_OPT_LIST_META_CONTEXT,
+ info->name, "qemu:", errp) < 0) {
+ return -1;
+ }
+ continue;
+ }
+ if (ret <= 0) {
+ return ret;
+ }
+ seen_any = true;
+ seen_qemu |= strstart(context, "qemu:", NULL);
+ info->contexts = g_renew(char *, info->contexts, ++info->n_contexts);
+ info->contexts[info->n_contexts - 1] = context;
+ }
}
-int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
- const char *hostname, QIOChannel **outioc,
- NBDExportInfo *info, Error **errp)
+/*
+ * nbd_start_negotiate:
+ * Start the handshake to the server. After a positive return, the server
+ * is ready to accept additional NBD_OPT requests.
+ * Returns: negative errno: failure talking to server
+ * 0: server is oldstyle, must call nbd_negotiate_finish_oldstyle
+ * 1: server is newstyle, but can only accept EXPORT_NAME
+ * 2: server is newstyle, but lacks structured replies
+ * 3: server is newstyle and set up for structured replies
+ */
+static int nbd_start_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
+ const char *hostname, QIOChannel **outioc,
+ bool structured_reply, bool *zeroes,
+ Error **errp)
{
uint64_t magic;
- int rc;
- bool zeroes = true;
- bool structured_reply = info->structured_reply;
- bool base_allocation = info->base_allocation;
-
- trace_nbd_receive_negotiate(tlscreds, hostname ? hostname : "<null>");
- assert(info->name);
- trace_nbd_receive_negotiate_name(info->name);
- info->structured_reply = false;
- info->base_allocation = false;
- rc = -EINVAL;
+ trace_nbd_start_negotiate(tlscreds, hostname ? hostname : "<null>");
+ if (zeroes) {
+ *zeroes = true;
+ }
if (outioc) {
*outioc = NULL;
}
if (tlscreds && !outioc) {
error_setg(errp, "Output I/O channel required for TLS");
- goto fail;
+ return -EINVAL;
}
- if (nbd_read(ioc, &magic, sizeof(magic), errp) < 0) {
- error_prepend(errp, "Failed to read initial magic: ");
- goto fail;
+ if (nbd_read64(ioc, &magic, "initial magic", errp) < 0) {
+ return -EINVAL;
}
- magic = be64_to_cpu(magic);
trace_nbd_receive_negotiate_magic(magic);
if (magic != NBD_INIT_MAGIC) {
error_setg(errp, "Bad initial magic received: 0x%" PRIx64, magic);
- goto fail;
+ return -EINVAL;
}
- if (nbd_read(ioc, &magic, sizeof(magic), errp) < 0) {
- error_prepend(errp, "Failed to read server magic: ");
- goto fail;
+ if (nbd_read64(ioc, &magic, "server magic", errp) < 0) {
+ return -EINVAL;
}
- magic = be64_to_cpu(magic);
trace_nbd_receive_negotiate_magic(magic);
if (magic == NBD_OPTS_MAGIC) {
uint16_t globalflags;
bool fixedNewStyle = false;
- if (nbd_read(ioc, &globalflags, sizeof(globalflags), errp) < 0) {
- error_prepend(errp, "Failed to read server flags: ");
- goto fail;
+ if (nbd_read16(ioc, &globalflags, "server flags", errp) < 0) {
+ return -EINVAL;
}
- globalflags = be16_to_cpu(globalflags);
trace_nbd_receive_negotiate_server_flags(globalflags);
if (globalflags & NBD_FLAG_FIXED_NEWSTYLE) {
fixedNewStyle = true;
clientflags |= NBD_FLAG_C_FIXED_NEWSTYLE;
}
if (globalflags & NBD_FLAG_NO_ZEROES) {
- zeroes = false;
+ if (zeroes) {
+ *zeroes = false;
+ }
clientflags |= NBD_FLAG_C_NO_ZEROES;
}
/* client requested flags */
clientflags = cpu_to_be32(clientflags);
if (nbd_write(ioc, &clientflags, sizeof(clientflags), errp) < 0) {
error_prepend(errp, "Failed to send clientflags field: ");
- goto fail;
+ return -EINVAL;
}
if (tlscreds) {
if (fixedNewStyle) {
*outioc = nbd_receive_starttls(ioc, tlscreds, hostname, errp);
if (!*outioc) {
- goto fail;
+ return -EINVAL;
}
ioc = *outioc;
} else {
error_setg(errp, "Server does not support STARTTLS");
- goto fail;
+ return -EINVAL;
}
}
if (fixedNewStyle) {
- int result;
+ int result = 0;
if (structured_reply) {
result = nbd_request_simple_option(ioc,
NBD_OPT_STRUCTURED_REPLY,
errp);
if (result < 0) {
- goto fail;
+ return -EINVAL;
}
- info->structured_reply = result == 1;
}
+ return 2 + result;
+ } else {
+ return 1;
+ }
+ } else if (magic == NBD_CLIENT_MAGIC) {
+ if (tlscreds) {
+ error_setg(errp, "Server does not support STARTTLS");
+ return -EINVAL;
+ }
+ return 0;
+ } else {
+ error_setg(errp, "Bad server magic received: 0x%" PRIx64, magic);
+ return -EINVAL;
+ }
+}
- if (info->structured_reply && base_allocation) {
- result = nbd_negotiate_simple_meta_context(ioc, info, errp);
- if (result < 0) {
- goto fail;
- }
- info->base_allocation = result == 1;
- }
+/*
+ * nbd_negotiate_finish_oldstyle:
+ * Populate @info with the size and export flags from an oldstyle server,
+ * but does not consume 124 bytes of reserved zero padding.
+ * Returns 0 on success, -1 with @errp set on failure
+ */
+static int nbd_negotiate_finish_oldstyle(QIOChannel *ioc, NBDExportInfo *info,
+ Error **errp)
+{
+ uint32_t oldflags;
- /* Try NBD_OPT_GO first - if it works, we are done (it
- * also gives us a good message if the server requires
- * TLS). If it is not available, fall back to
- * NBD_OPT_LIST for nicer error messages about a missing
- * export, then use NBD_OPT_EXPORT_NAME. */
- result = nbd_opt_go(ioc, info, errp);
+ if (nbd_read64(ioc, &info->size, "export length", errp) < 0) {
+ return -EINVAL;
+ }
+
+ if (nbd_read32(ioc, &oldflags, "export flags", errp) < 0) {
+ return -EINVAL;
+ }
+ if (oldflags & ~0xffff) {
+ error_setg(errp, "Unexpected export flags %0x" PRIx32, oldflags);
+ return -EINVAL;
+ }
+ info->flags = oldflags;
+ return 0;
+}
+
+/*
+ * nbd_receive_negotiate:
+ * Connect to server, complete negotiation, and move into transmission phase.
+ * Returns: negative errno: failure talking to server
+ * 0: server is connected
+ */
+int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
+ const char *hostname, QIOChannel **outioc,
+ NBDExportInfo *info, Error **errp)
+{
+ int result;
+ bool zeroes;
+ bool base_allocation = info->base_allocation;
+
+ assert(info->name);
+ trace_nbd_receive_negotiate_name(info->name);
+
+ result = nbd_start_negotiate(ioc, tlscreds, hostname, outioc,
+ info->structured_reply, &zeroes, errp);
+
+ info->structured_reply = false;
+ info->base_allocation = false;
+ if (tlscreds && *outioc) {
+ ioc = *outioc;
+ }
+
+ switch (result) {
+ case 3: /* newstyle, with structured replies */
+ info->structured_reply = true;
+ if (base_allocation) {
+ result = nbd_negotiate_simple_meta_context(ioc, info, errp);
if (result < 0) {
- goto fail;
- }
- if (result > 0) {
- return 0;
- }
- /* Check our desired export is present in the
- * server export list. Since NBD_OPT_EXPORT_NAME
- * cannot return an error message, running this
- * query gives us better error reporting if the
- * export name is not available.
- */
- if (nbd_receive_query_exports(ioc, info->name, errp) < 0) {
- goto fail;
+ return -EINVAL;
}
+ info->base_allocation = result == 1;
}
+ /* fall through */
+ case 2: /* newstyle, try OPT_GO */
+ /* Try NBD_OPT_GO first - if it works, we are done (it
+ * also gives us a good message if the server requires
+ * TLS). If it is not available, fall back to
+ * NBD_OPT_LIST for nicer error messages about a missing
+ * export, then use NBD_OPT_EXPORT_NAME. */
+ result = nbd_opt_info_or_go(ioc, NBD_OPT_GO, info, errp);
+ if (result < 0) {
+ return -EINVAL;
+ }
+ if (result > 0) {
+ return 0;
+ }
+ /* Check our desired export is present in the
+ * server export list. Since NBD_OPT_EXPORT_NAME
+ * cannot return an error message, running this
+ * query gives us better error reporting if the
+ * export name is not available.
+ */
+ if (nbd_receive_query_exports(ioc, info->name, errp) < 0) {
+ return -EINVAL;
+ }
+ /* fall through */
+ case 1: /* newstyle, but limited to EXPORT_NAME */
/* write the export name request */
if (nbd_send_option_request(ioc, NBD_OPT_EXPORT_NAME, -1, info->name,
errp) < 0) {
- goto fail;
+ return -EINVAL;
}
/* Read the response */
- if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) {
- error_prepend(errp, "Failed to read export length: ");
- goto fail;
+ if (nbd_read64(ioc, &info->size, "export length", errp) < 0) {
+ return -EINVAL;
}
- info->size = be64_to_cpu(info->size);
- if (nbd_read(ioc, &info->flags, sizeof(info->flags), errp) < 0) {
- error_prepend(errp, "Failed to read export flags: ");
- goto fail;
+ if (nbd_read16(ioc, &info->flags, "export flags", errp) < 0) {
+ return -EINVAL;
}
- info->flags = be16_to_cpu(info->flags);
- } else if (magic == NBD_CLIENT_MAGIC) {
- uint32_t oldflags;
-
+ break;
+ case 0: /* oldstyle, parse length and flags */
if (*info->name) {
error_setg(errp, "Server does not support non-empty export names");
- goto fail;
+ return -EINVAL;
}
- if (tlscreds) {
- error_setg(errp, "Server does not support STARTTLS");
- goto fail;
+ if (nbd_negotiate_finish_oldstyle(ioc, info, errp) < 0) {
+ return -EINVAL;
}
+ break;
+ default:
+ return result;
+ }
- if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) {
- error_prepend(errp, "Failed to read export length: ");
- goto fail;
+ trace_nbd_receive_negotiate_size_flags(info->size, info->flags);
+ if (zeroes && nbd_drop(ioc, 124, errp) < 0) {
+ error_prepend(errp, "Failed to read reserved block: ");
+ return -EINVAL;
+ }
+ return 0;
+}
+
+/* Clean up result of nbd_receive_export_list */
+void nbd_free_export_list(NBDExportInfo *info, int count)
+{
+ int i, j;
+
+ if (!info) {
+ return;
+ }
+
+ for (i = 0; i < count; i++) {
+ g_free(info[i].name);
+ g_free(info[i].description);
+ for (j = 0; j < info[i].n_contexts; j++) {
+ g_free(info[i].contexts[j]);
}
- info->size = be64_to_cpu(info->size);
+ g_free(info[i].contexts);
+ }
+ g_free(info);
+}
- if (nbd_read(ioc, &oldflags, sizeof(oldflags), errp) < 0) {
- error_prepend(errp, "Failed to read export flags: ");
- goto fail;
+/*
+ * nbd_receive_export_list:
+ * Query details about a server's exports, then disconnect without
+ * going into transmission phase. Return a count of the exports listed
+ * in @info by the server, or -1 on error. Caller must free @info using
+ * nbd_free_export_list().
+ */
+int nbd_receive_export_list(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
+ const char *hostname, NBDExportInfo **info,
+ Error **errp)
+{
+ int result;
+ int count = 0;
+ int i;
+ int rc;
+ int ret = -1;
+ NBDExportInfo *array = NULL;
+ QIOChannel *sioc = NULL;
+
+ *info = NULL;
+ result = nbd_start_negotiate(ioc, tlscreds, hostname, &sioc, true, NULL,
+ errp);
+ if (tlscreds && sioc) {
+ ioc = sioc;
+ }
+
+ switch (result) {
+ case 2:
+ case 3:
+ /* newstyle - use NBD_OPT_LIST to populate array, then try
+ * NBD_OPT_INFO on each array member. If structured replies
+ * are enabled, also try NBD_OPT_LIST_META_CONTEXT. */
+ if (nbd_send_option_request(ioc, NBD_OPT_LIST, 0, NULL, errp) < 0) {
+ goto out;
}
- oldflags = be32_to_cpu(oldflags);
- if (oldflags & ~0xffff) {
- error_setg(errp, "Unexpected export flags %0x" PRIx32, oldflags);
- goto fail;
+ while (1) {
+ char *name;
+ char *desc;
+
+ rc = nbd_receive_list(ioc, &name, &desc, errp);
+ if (rc < 0) {
+ goto out;
+ } else if (rc == 0) {
+ break;
+ }
+ array = g_renew(NBDExportInfo, array, ++count);
+ memset(&array[count - 1], 0, sizeof(*array));
+ array[count - 1].name = name;
+ array[count - 1].description = desc;
+ array[count - 1].structured_reply = result == 3;
}
- info->flags = oldflags;
- } else {
- error_setg(errp, "Bad server magic received: 0x%" PRIx64, magic);
- goto fail;
- }
- trace_nbd_receive_negotiate_size_flags(info->size, info->flags);
- if (zeroes && nbd_drop(ioc, 124, errp) < 0) {
- error_prepend(errp, "Failed to read reserved block: ");
- goto fail;
+ for (i = 0; i < count; i++) {
+ array[i].request_sizes = true;
+ rc = nbd_opt_info_or_go(ioc, NBD_OPT_INFO, &array[i], errp);
+ if (rc < 0) {
+ goto out;
+ } else if (rc == 0) {
+ /*
+ * Pointless to try rest of loop. If OPT_INFO doesn't work,
+ * it's unlikely that meta contexts work either
+ */
+ break;
+ }
+
+ if (result == 3 &&
+ nbd_list_meta_contexts(ioc, &array[i], errp) < 0) {
+ goto out;
+ }
+ }
+
+ /* Send NBD_OPT_ABORT as a courtesy before hanging up */
+ nbd_send_opt_abort(ioc);
+ break;
+ case 1: /* newstyle, but limited to EXPORT_NAME */
+ error_setg(errp, "Server does not support export lists");
+ /* We can't even send NBD_OPT_ABORT, so merely hang up */
+ goto out;
+ case 0: /* oldstyle, parse length and flags */
+ array = g_new0(NBDExportInfo, 1);
+ array->name = g_strdup("");
+ count = 1;
+
+ if (nbd_negotiate_finish_oldstyle(ioc, array, errp) < 0) {
+ goto out;
+ }
+
+ /* Send NBD_CMD_DISC as a courtesy to the server, but ignore all
+ * errors now that we have the information we wanted. */
+ if (nbd_drop(ioc, 124, NULL) == 0) {
+ NBDRequest request = { .type = NBD_CMD_DISC };
+
+ nbd_send_request(ioc, &request);
+ }
+ break;
+ default:
+ goto out;
}
- rc = 0;
-fail:
- return rc;
+ *info = array;
+ array = NULL;
+ ret = count;
+
+ out:
+ qio_channel_shutdown(ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
+ qio_channel_close(ioc, NULL);
+ object_unref(OBJECT(sioc));
+ nbd_free_export_list(array, count);
+ return ret;
}
#ifdef __linux__
assert(reply->magic == NBD_SIMPLE_REPLY_MAGIC);
ret = nbd_read(ioc, (uint8_t *)reply + sizeof(reply->magic),
- sizeof(*reply) - sizeof(reply->magic), errp);
+ sizeof(*reply) - sizeof(reply->magic), "reply", errp);
if (ret < 0) {
return ret;
}
assert(chunk->magic == NBD_STRUCTURED_REPLY_MAGIC);
ret = nbd_read(ioc, (uint8_t *)chunk + sizeof(chunk->magic),
- sizeof(*chunk) - sizeof(chunk->magic), errp);
+ sizeof(*chunk) - sizeof(chunk->magic), "structured chunk",
+ errp);
if (ret < 0) {
return ret;
}
return 0;
}
+/* nbd_read_eof
+ * Tries to read @size bytes from @ioc.
+ * 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(BlockDriverState *bs, QIOChannel *ioc, 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(ioc, &iov, 1, errp);
+ if (len == QIO_CHANNEL_ERR_BLOCK) {
+ bdrv_dec_in_flight(bs);
+ qio_channel_yield(ioc, G_IO_IN);
+ bdrv_inc_in_flight(bs);
+ 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;
+}
+
/* 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().
+ *
* Returns 1 on success
* 0 on eof, when no data was read (errp is not set)
* negative errno on failure (errp is set)
*/
-int nbd_receive_reply(QIOChannel *ioc, NBDReply *reply, Error **errp)
+int coroutine_fn nbd_receive_reply(BlockDriverState *bs, QIOChannel *ioc,
+ NBDReply *reply, Error **errp)
{
int ret;
const char *type;
- ret = nbd_read_eof(ioc, &reply->magic, sizeof(reply->magic), errp);
+ ret = nbd_read_eof(bs, ioc, &reply->magic, sizeof(reply->magic), errp);
if (ret <= 0) {
return ret;
}
projects / qemu.git / blobdiff