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Diffstat (limited to 'nbd')
-rw-r--r--nbd/client.c145
-rw-r--r--nbd/trace-events2
2 files changed, 96 insertions, 51 deletions
diff --git a/nbd/client.c b/nbd/client.c
index 9028fd0939..77cc12356f 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -809,22 +809,26 @@ static int nbd_negotiate_simple_meta_context(QIOChannel *ioc,
return received;
}
-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, client must still parse export size
+ * 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;
- 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;
+ trace_nbd_start_negotiate(tlscreds, hostname ? hostname : "<null>");
+ *zeroes = true;
if (outioc) {
*outioc = NULL;
}
@@ -868,7 +872,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
clientflags |= NBD_FLAG_C_FIXED_NEWSTYLE;
}
if (globalflags & NBD_FLAG_NO_ZEROES) {
- zeroes = false;
+ *zeroes = false;
clientflags |= NBD_FLAG_C_NO_ZEROES;
}
/* client requested flags */
@@ -890,7 +894,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
}
}
if (fixedNewStyle) {
- int result;
+ int result = 0;
if (structured_reply) {
result = nbd_request_simple_option(ioc,
@@ -899,39 +903,85 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
if (result < 0) {
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) {
- return -EINVAL;
- }
- info->base_allocation = result == 1;
- }
+/*
+ * 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;
+ 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);
+ 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) {
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;
- }
+ 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_go(ioc, 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) {
@@ -950,17 +1000,12 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
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");
return -EINVAL;
}
- if (tlscreds) {
- error_setg(errp, "Server does not support STARTTLS");
- return -EINVAL;
- }
if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) {
error_prepend(errp, "Failed to read export length: ");
@@ -978,9 +1023,9 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
return -EINVAL;
}
info->flags = oldflags;
- } else {
- error_setg(errp, "Bad server magic received: 0x%" PRIx64, magic);
- return -EINVAL;
+ break;
+ default:
+ return result;
}
trace_nbd_receive_negotiate_size_flags(info->size, info->flags);
diff --git a/nbd/trace-events b/nbd/trace-events
index b4802c1570..663d11687a 100644
--- a/nbd/trace-events
+++ b/nbd/trace-events
@@ -14,7 +14,7 @@ nbd_receive_starttls_new_client(void) "Setting up TLS"
nbd_receive_starttls_tls_handshake(void) "Starting TLS handshake"
nbd_opt_meta_request(const char *optname, const char *context, const char *export) "Requesting %s %s for export %s"
nbd_opt_meta_reply(const char *optname, const char *context, uint32_t id) "Received %s mapping of %s to id %" PRIu32
-nbd_receive_negotiate(void *tlscreds, const char *hostname) "Receiving negotiation tlscreds=%p hostname=%s"
+nbd_start_negotiate(void *tlscreds, const char *hostname) "Receiving negotiation tlscreds=%p hostname=%s"
nbd_receive_negotiate_magic(uint64_t magic) "Magic is 0x%" PRIx64
nbd_receive_negotiate_server_flags(uint32_t globalflags) "Global flags are 0x%" PRIx32
nbd_receive_negotiate_name(const char *name) "Requesting NBD export name '%s'"
generated by cgit v1.2.3 (git 2.26.2) at 2024-12-11 11:49:15 +0000