nbd/client: Request extended headers during negotiation

All the pieces are in place for a client to finally request extended
headers.  Note that we must not request extended headers when qemu-nbd
is used to connect to the kernel module (as nbd.ko does not expect
them, but expects us to do the negotiation in userspace before handing
the socket over to the kernel), but there is no harm in all other
clients requesting them.

Extended headers are not essential to the information collected during
'qemu-nbd --list', but probing for it gives us one more piece of
information in that output.  Update the iotests affected by the new
line of output.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-ID: <20230925192229.3186470-23-eblake@redhat.com>

nbd/client-connection.c

@@ -93,7 +93,7 @@ NBDClientConnection *nbd_client_connection_new(const SocketAddress *saddr,
         .do_negotiation = do_negotiation,
 
         .initial_info.request_sizes = true,
-        .initial_info.mode = NBD_MODE_STRUCTURED,
+        .initial_info.mode = NBD_MODE_EXTENDED,
         .initial_info.base_allocation = true,
         .initial_info.x_dirty_bitmap = g_strdup(x_dirty_bitmap),
         .initial_info.name = g_strdup(export_name ?: "")

nbd/client.c

@@ -953,15 +953,23 @@ static int nbd_start_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
         if (fixedNewStyle) {
             int result = 0;
 
+            if (max_mode >= NBD_MODE_EXTENDED) {
+                result = nbd_request_simple_option(ioc,
+                                                   NBD_OPT_EXTENDED_HEADERS,
+                                                   false, errp);
+                if (result) {
+                    return result < 0 ? -EINVAL : NBD_MODE_EXTENDED;
+                }
+            }
             if (max_mode >= NBD_MODE_STRUCTURED) {
                 result = nbd_request_simple_option(ioc,
                                                    NBD_OPT_STRUCTURED_REPLY,
                                                    false, errp);
-                if (result < 0) {
-                    return -EINVAL;
+                if (result) {
+                    return result < 0 ? -EINVAL : NBD_MODE_STRUCTURED;
                 }
             }
-            return result ? NBD_MODE_STRUCTURED : NBD_MODE_SIMPLE;
+            return NBD_MODE_SIMPLE;
         } else {
             return NBD_MODE_EXPORT_NAME;
         }
@@ -1034,6 +1042,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
     }
 
     switch (info->mode) {
+    case NBD_MODE_EXTENDED:
     case NBD_MODE_STRUCTURED:
         if (base_allocation) {
             result = nbd_negotiate_simple_meta_context(ioc, info, errp);
@@ -1144,7 +1153,7 @@ int nbd_receive_export_list(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
 
     *info = NULL;
     result = nbd_start_negotiate(ioc, tlscreds, hostname, &sioc,
-                                 NBD_MODE_STRUCTURED, NULL, errp);
+                                 NBD_MODE_EXTENDED, NULL, errp);
     if (tlscreds && sioc) {
         ioc = sioc;
     }
@@ -1155,6 +1164,7 @@ int nbd_receive_export_list(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
     switch ((NBDMode)result) {
     case NBD_MODE_SIMPLE:
     case NBD_MODE_STRUCTURED:
+    case NBD_MODE_EXTENDED:
         /* 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. */
@@ -1191,7 +1201,7 @@ int nbd_receive_export_list(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
                 break;
             }
 
-            if (result == NBD_MODE_STRUCTURED &&
+            if (result >= NBD_MODE_STRUCTURED &&
                 nbd_list_meta_contexts(ioc, &array[i], errp) < 0) {
                 goto out;
             }

qemu-nbd.c

@@ -235,6 +235,9 @@ static int qemu_nbd_client_list(SocketAddress *saddr, QCryptoTLSCreds *tls,
             printf("  opt block: %u\n", list[i].opt_block);
             printf("  max block: %u\n", list[i].max_block);
         }
+        printf("  transaction size: %s\n",
+               list[i].mode >= NBD_MODE_EXTENDED ?
+               "64-bit" : "32-bit");
         if (list[i].n_contexts) {
             printf("  available meta contexts: %d\n", list[i].n_contexts);
             for (j = 0; j < list[i].n_contexts; j++) {

tests/qemu-iotests/223.out

@@ -87,6 +87,7 @@ exports available: 3
   min block: 1
   opt block: 4096
   max block: 33554432
+  transaction size: 64-bit
   available meta contexts: 2
    base:allocation
    qemu:dirty-bitmap:b
@@ -97,6 +98,7 @@ exports available: 3
   min block: 1
   opt block: 4096
   max block: 33554432
+  transaction size: 64-bit
   available meta contexts: 2
    base:allocation
    qemu:dirty-bitmap:b2
@@ -106,6 +108,7 @@ exports available: 3
   min block: 1
   opt block: 4096
   max block: 33554432
+  transaction size: 64-bit
   available meta contexts: 2
    base:allocation
    qemu:dirty-bitmap:b3
@@ -206,6 +209,7 @@ exports available: 3
   min block: 1
   opt block: 4096
   max block: 33554432
+  transaction size: 64-bit
   available meta contexts: 2
    base:allocation
    qemu:dirty-bitmap:b
@@ -216,6 +220,7 @@ exports available: 3
   min block: 1
   opt block: 4096
   max block: 33554432
+  transaction size: 64-bit
   available meta contexts: 2
    base:allocation
    qemu:dirty-bitmap:b2
@@ -225,6 +230,7 @@ exports available: 3
   min block: 1
   opt block: 4096
   max block: 33554432
+  transaction size: 64-bit
   available meta contexts: 2
    base:allocation
    qemu:dirty-bitmap:b3

tests/qemu-iotests/233.out

@@ -39,6 +39,7 @@ exports available: 1
  export: ''
   size:  67108864
   min block: 1
+  transaction size: 64-bit
 
 == check TLS fail over TCP with mismatched hostname ==
 qemu-img: Could not open 'driver=nbd,host=localhost,port=PORT,tls-creds=tls0': Certificate does not match the hostname localhost
@@ -53,6 +54,7 @@ exports available: 1
  export: ''
   size:  67108864
   min block: 1
+  transaction size: 64-bit
 
 == check TLS with different CA fails ==
 qemu-img: Could not open 'driver=nbd,host=127.0.0.1,port=PORT,tls-creds=tls0': The certificate hasn't got a known issuer
@@ -83,6 +85,7 @@ exports available: 1
  export: ''
   size:  67108864
   min block: 1
+  transaction size: 64-bit
 
 == check TLS works over UNIX with PSK ==
 image: nbd+unix://?socket=SOCK_DIR/qemu-nbd.sock
@@ -93,6 +96,7 @@ exports available: 1
  export: ''
   size:  67108864
   min block: 1
+  transaction size: 64-bit
 
 == check TLS fails over UNIX with mismatch PSK ==
 qemu-img: Could not open 'driver=nbd,path=SOCK_DIR/qemu-nbd.sock,tls-creds=tls0': TLS handshake failed: The TLS connection was non-properly terminated.

tests/qemu-iotests/241.out

@@ -6,6 +6,7 @@ exports available: 1
  export: ''
   size:  1024
   min block: 1
+  transaction size: 64-bit
 [{ "start": 0, "length": 1000, "depth": 0, "present": true, "zero": false, "data": true, "compressed": false, "offset": OFFSET},
 { "start": 1000, "length": 24, "depth": 0, "present": true, "zero": true, "data": false, "compressed": false, "offset": OFFSET}]
 1 KiB (0x400) bytes     allocated at offset 0 bytes (0x0)
@@ -16,6 +17,7 @@ exports available: 1
  export: ''
   size:  1024
   min block: 512
+  transaction size: 64-bit
 [{ "start": 0, "length": 1024, "depth": 0, "present": true, "zero": false, "data": true, "compressed": false, "offset": OFFSET}]
 1 KiB (0x400) bytes     allocated at offset 0 bytes (0x0)
 WARNING: Image format was not specified for 'TEST_DIR/t.raw' and probing guessed raw.
@@ -28,6 +30,7 @@ exports available: 1
  export: ''
   size:  1024
   min block: 1
+  transaction size: 64-bit
 [{ "start": 0, "length": 1000, "depth": 0, "present": true, "zero": false, "data": true, "compressed": false, "offset": OFFSET},
 { "start": 1000, "length": 24, "depth": 0, "present": true, "zero": true, "data": false, "compressed": false, "offset": OFFSET}]
 1 KiB (0x400) bytes     allocated at offset 0 bytes (0x0)

tests/qemu-iotests/307.out

@@ -19,6 +19,7 @@ exports available: 1
   min block: XXX
   opt block: XXX
   max block: XXX
+  transaction size: 64-bit
   available meta contexts: 1
    base:allocation
 
@@ -47,6 +48,7 @@ exports available: 1
   min block: XXX
   opt block: XXX
   max block: XXX
+  transaction size: 64-bit
   available meta contexts: 1
    base:allocation
 
@@ -78,6 +80,7 @@ exports available: 2
   min block: XXX
   opt block: XXX
   max block: XXX
+  transaction size: 64-bit
   available meta contexts: 1
    base:allocation
  export: 'export1'
@@ -87,6 +90,7 @@ exports available: 2
   min block: XXX
   opt block: XXX
   max block: XXX
+  transaction size: 64-bit
   available meta contexts: 1
    base:allocation
 
@@ -113,6 +117,7 @@ exports available: 1
   min block: XXX
   opt block: XXX
   max block: XXX
+  transaction size: 64-bit
   available meta contexts: 1
    base:allocation
 

tests/qemu-iotests/tests/nbd-qemu-allocation.out

@@ -21,6 +21,7 @@ exports available: 1
   min block: 1
   opt block: 4096
   max block: 33554432
+  transaction size: 64-bit
   available meta contexts: 2
    base:allocation
    qemu:allocation-depth