5:17 p.m.
The new NBD_OPT_EXTENDED_HEADERS feature is worth using by default,
but there may be cases where the user explicitly wants to stick with
the older 32-bit headers. nbd_set_request_extended_headers() will let
the client override the default, nbd_get_request_extended_headers()
determines the current state of the request, and
nbd_get_extended_headers_negotiated() determines what the client and
server actually settled on. These use
nbd_set_request_structured_headers() and friends as a template.
Note that this patch just adds the API but ignores the state variable;
the next one will then tweak the state machine to actually request
structured headers when the state variable is set.
---
lib/internal.h | 1 +
generator/API.ml | 89 ++++++++++++++++++++--
lib/handle.c | 23 ++++++
python/t/110-defaults.py | 3 +-
python/t/120-set-non-defaults.py | 4 +-
ocaml/tests/test_110_defaults.ml | 4 +-
ocaml/tests/test_120_set_non_defaults.ml | 5 +-
golang/libnbd_110_defaults_test.go | 8 ++
golang/libnbd_120_set_non_defaults_test.go | 12 +++
9 files changed, 137 insertions(+), 12 deletions(-)
diff --git a/lib/internal.h b/lib/internal.h
index 97abf4f2..a579e413 100644
--- a/lib/internal.h
+++ b/lib/internal.h
@@ -107,6 +107,7 @@ struct nbd_handle {
char *tls_psk_file; /* PSK filename, NULL = no PSK */
/* Extended headers. */
+ bool request_eh; /* Whether to request extended headers */
bool extended_headers; /* If we negotiated NBD_OPT_EXTENDED_HEADERS */
/* Desired metadata contexts. */
diff --git a/generator/API.ml b/generator/API.ml
index 1a452a24..e45f0c86 100644
--- a/generator/API.ml
+++ b/generator/API.ml
@@ -675,6 +675,63 @@ "get_tls_psk_file", {
};
*)
+ "set_request_extended_headers", {
+ default_call with
+ args = [Bool "request"]; ret = RErr;
+ permitted_states = [ Created ];
+ shortdesc = "control use of extended headers";
+ longdesc = "\
+By default, libnbd tries to negotiate extended headers with the
+server, as this protocol extension permits the use of 64-bit
+zero, trim, and block status actions. However,
+for integration testing, it can be useful to clear this flag
+rather than find a way to alter the server to fail the negotiation
+request.";
+ see_also = [Link "get_request_extended_headers";
+ Link "set_handshake_flags"; Link "set_strict_mode";
+ Link "get_extended_headers_negotiated";
+ Link "zero"; Link "trim"; Link "cache";
+ Link "block_status_64";
+ Link "set_request_structured_replies"];
+ };
+
+ "get_request_extended_headers", {
+ default_call with
+ args = []; ret = RBool;
+ may_set_error = false;
+ shortdesc = "see if extended headers are attempted";
+ longdesc = "\
+Return the state of the request extended headers flag on this
+handle.
+
+B<Note:> If you want to find out if extended headers were actually
+negotiated on a particular connection use
+L<nbd_get_extended_headers_negotiated(3)> instead.";
+ see_also = [Link "set_request_extended_headers";
+ Link "get_extended_headers_negotiated";
+ Link "get_request_extended_headers"];
+ };
+
+ "get_extended_headers_negotiated", {
+ default_call with
+ args = []; ret = RBool;
+ permitted_states = [ Negotiating; Connected; Closed ];
+ shortdesc = "see if extended headers are in use";
+ longdesc = "\
+After connecting you may call this to find out if the connection is
+using extended headers. When extended headers are not in use, commands
+are limited to a 32-bit length, even when the libnbd API uses a 64-bit
+variable to express the length. But even when extended headers are
+supported, the server may enforce other limits, visible through
+L<nbd_get_block_size(3)>.";
+ see_also = [Link "set_request_extended_headers";
+ Link "get_request_extended_headers";
+ Link "zero"; Link "trim"; Link "cache";
+ Link "block_status_64"; Link "get_block_size";
+ Link "get_protocol";
+ Link "get_structured_replies_negotiated"];
+ };
+
"set_request_structured_replies", {
default_call with
args = [Bool "request"]; ret = RErr;
@@ -690,7 +747,8 @@ "set_request_structured_replies", {
see_also = [Link "get_request_structured_replies";
Link "set_handshake_flags"; Link "set_strict_mode";
Link "get_structured_replies_negotiated";
- Link "can_meta_context"; Link "can_df"];
+ Link "can_meta_context"; Link "can_df";
+ Link "set_request_extended_headers"];
};
"get_request_structured_replies", {
@@ -706,7 +764,8 @@ "get_request_structured_replies", {
negotiated on a particular connection use
L<nbd_get_structured_replies_negotiated(3)> instead.";
see_also = [Link "set_request_structured_replies";
- Link "get_structured_replies_negotiated"];
+ Link "get_structured_replies_negotiated";
+ Link "get_request_extended_headers"];
};
"get_structured_replies_negotiated", {
@@ -719,7 +778,8 @@ "get_structured_replies_negotiated", {
using structured replies.";
see_also = [Link "set_request_structured_replies";
Link "get_request_structured_replies";
- Link "get_protocol"];
+ Link "get_protocol";
+ Link "get_extended_headers_negotiated"];
};
"set_handshake_flags", {
@@ -2035,7 +2095,9 @@ "trim", {
or there is an error. Note this will generally return an error
if L<nbd_can_trim(3)> is false or L<nbd_is_read_only(3)> is true.
-Note that not all servers can support a C<count> of 4GiB or larger.
+Note that not all servers can support a C<count> of 4GiB or larger;
+L<nbd_get_extended_headers_negotiated(3)> indicates which servers
+will parse a request larger than 32 bits.
The NBD protocol does not yet have a way for a client to learn if
the server will enforce an even smaller maximum trim size, although
a future extension may add a constraint visible in
@@ -2066,7 +2128,9 @@ "cache", {
this command. Note this will generally return an error if
L<nbd_can_cache(3)> is false.
-Note that not all servers can support a C<count> of 4GiB or larger.
+Note that not all servers can support a C<count> of 4GiB or larger;
+L<nbd_get_extended_headers_negotiated(3)> indicates which servers
+will parse a request larger than 32 bits.
The NBD protocol does not yet have a way for a client to learn if
the server will enforce an even smaller maximum cache size, although
a future extension may add a constraint visible in
@@ -2095,7 +2159,9 @@ "zero", {
or there is an error. Note this will generally return an error if
L<nbd_can_zero(3)> is false or L<nbd_is_read_only(3)> is true.
-Note that not all servers can support a C<count> of 4GiB or larger.
+Note that not all servers can support a C<count> of 4GiB or larger;
+L<nbd_get_extended_headers_negotiated(3)> indicates which servers
+will parse a request larger than 32 bits.
The NBD protocol does not yet have a way for a client to learn if
the server will enforce an even smaller maximum zero size, although
a future extension may add a constraint visible in
@@ -2135,7 +2201,9 @@ "block_status", {
are supported, the number of blocks and cumulative length
of those blocks need not be identical between contexts.
-Note that not all servers can support a C<count> of 4GiB or larger.
+Note that not all servers can support a C<count> of 4GiB or larger;
+L<nbd_get_extended_headers_negotiated(3)> indicates which servers
+will parse a request larger than 32 bits.
The NBD protocol does not yet have a way for a client to learn if
the server will enforce an even smaller maximum block status size,
although a future extension may add a constraint visible in
@@ -2209,7 +2277,9 @@ "block_status_64", {
are supported, the number of blocks and cumulative length
of those blocks need not be identical between contexts.
-Note that not all servers can support a C<count> of 4GiB or larger.
+Note that not all servers can support a C<count> of 4GiB or larger;
+L<nbd_get_extended_headers_negotiated(3)> indicates which servers
+will parse a request larger than 32 bits.
The NBD protocol does not yet have a way for a client to learn if
the server will enforce an even smaller maximum block status size,
although a future extension may add a constraint visible in
@@ -3239,6 +3309,9 @@ let first_version =
(* Added in 1.11.x development cycle, will be stable and supported in 1.12. *)
"block_status_64", (1, 12);
"aio_block_status_64", (1, 12);
+ "set_request_extended_headers", (1, 12);
+ "get_request_extended_headers", (1, 12);
+ "get_extended_headers_negotiated", (1, 12);
(* These calls are proposed for a future version of libnbd, but
* have not been added to any released version so far.
diff --git a/lib/handle.c b/lib/handle.c
index 74fe87ec..9b96c7f7 100644
--- a/lib/handle.c
+++ b/lib/handle.c
@@ -63,6 +63,7 @@ nbd_create (void)
h->unique = 1;
h->tls_verify_peer = true;
+ h->request_eh = true;
h->request_sr = true;
h->uri_allow_transports = LIBNBD_ALLOW_TRANSPORT_MASK;
@@ -356,6 +357,28 @@ nbd_unlocked_clear_meta_contexts (struct nbd_handle *h)
return 0;
}
+
+int
+nbd_unlocked_set_request_extended_headers (struct nbd_handle *h,
+ bool request)
+{
+ h->request_eh = request;
+ return 0;
+}
+
+/* NB: may_set_error = false. */
+int
+nbd_unlocked_get_request_extended_headers (struct nbd_handle *h)
+{
+ return h->request_eh;
+}
+
+int
+nbd_unlocked_get_extended_headers_negotiated (struct nbd_handle *h)
+{
+ return h->extended_headers;
+}
+
int
nbd_unlocked_set_request_structured_replies (struct nbd_handle *h,
bool request)
diff --git a/python/t/110-defaults.py b/python/t/110-defaults.py
index fb961cfd..ecd4dfda 100644
--- a/python/t/110-defaults.py
+++ b/python/t/110-defaults.py
@@ -1,5 +1,5 @@
# libnbd Python bindings
-# Copyright (C) 2010-2020 Red Hat Inc.
+# Copyright (C) 2010-2021 Red Hat Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
@@ -21,6 +21,7 @@ h = nbd.NBD()
assert h.get_export_name() == ""
assert h.get_full_info() is False
assert h.get_tls() == nbd.TLS_DISABLE
+assert h.get_request_extended_headers() is True
assert h.get_request_structured_replies() is True
assert h.get_handshake_flags() == nbd.HANDSHAKE_FLAG_MASK
assert h.get_opt_mode() is False
diff --git a/python/t/120-set-non-defaults.py b/python/t/120-set-non-defaults.py
index 3da0c23e..b34fb508 100644
--- a/python/t/120-set-non-defaults.py
+++ b/python/t/120-set-non-defaults.py
@@ -1,5 +1,5 @@
# libnbd Python bindings
-# Copyright (C) 2010-2020 Red Hat Inc.
+# Copyright (C) 2010-2021 Red Hat Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
@@ -31,6 +31,8 @@ assert h.get_tls() == nbd.TLS_DISABLE
if h.supports_tls():
h.set_tls(nbd.TLS_ALLOW)
assert h.get_tls() == nbd.TLS_ALLOW
+h.set_request_extended_headers(False)
+assert h.get_request_extended_headers() is False
h.set_request_structured_replies(False)
assert h.get_request_structured_replies() is False
try:
diff --git a/ocaml/tests/test_110_defaults.ml b/ocaml/tests/test_110_defaults.ml
index f5886fca..5fe448b6 100644
--- a/ocaml/tests/test_110_defaults.ml
+++ b/ocaml/tests/test_110_defaults.ml
@@ -1,6 +1,6 @@
(* hey emacs, this is OCaml code: -*- tuareg -*- *)
(* libnbd OCaml test case
- * Copyright (C) 2013-2020 Red Hat Inc.
+ * Copyright (C) 2013-2021 Red Hat Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
@@ -25,6 +25,8 @@ let
assert (info = false);
let tls = NBD.get_tls nbd in
assert (tls = NBD.TLS.DISABLE);
+ let eh = NBD.get_request_extended_headers nbd in
+ assert (eh = true);
let sr = NBD.get_request_structured_replies nbd in
assert (sr = true);
let flags = NBD.get_handshake_flags nbd in
diff --git a/ocaml/tests/test_120_set_non_defaults.ml
b/ocaml/tests/test_120_set_non_defaults.ml
index b660e5d5..47914d9c 100644
--- a/ocaml/tests/test_120_set_non_defaults.ml
+++ b/ocaml/tests/test_120_set_non_defaults.ml
@@ -1,6 +1,6 @@
(* hey emacs, this is OCaml code: -*- tuareg -*- *)
(* libnbd OCaml test case
- * Copyright (C) 2013-2020 Red Hat Inc.
+ * Copyright (C) 2013-2021 Red Hat Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
@@ -37,6 +37,9 @@ let
let tls = NBD.get_tls nbd in
assert (tls = NBD.TLS.ALLOW);
);
+ NBD.set_request_extended_headers nbd false;
+ let eh = NBD.get_request_extended_headers nbd in
+ assert (eh = false);
NBD.set_request_structured_replies nbd false;
let sr = NBD.get_request_structured_replies nbd in
assert (sr = false);
diff --git a/golang/libnbd_110_defaults_test.go b/golang/libnbd_110_defaults_test.go
index b3ceb45d..659ea18c 100644
--- a/golang/libnbd_110_defaults_test.go
+++ b/golang/libnbd_110_defaults_test.go
@@ -51,6 +51,14 @@ func Test110Defaults(t *testing.T) {
t.Fatalf("unexpected tls state")
}
+ eh, err := h.GetRequestExtendedHeaders()
+ if err != nil {
+ t.Fatalf("could not get extended headers state: %s", err)
+ }
+ if eh != true {
+ t.Fatalf("unexpected extended headers state")
+ }
+
sr, err := h.GetRequestStructuredReplies()
if err != nil {
t.Fatalf("could not get structured replies state: %s", err)
diff --git a/golang/libnbd_120_set_non_defaults_test.go
b/golang/libnbd_120_set_non_defaults_test.go
index f112456c..d27ec5dc 100644
--- a/golang/libnbd_120_set_non_defaults_test.go
+++ b/golang/libnbd_120_set_non_defaults_test.go
@@ -81,6 +81,18 @@ func Test120SetNonDefaults(t *testing.T) {
}
}
+ err = h.SetRequestExtendedHeaders(false)
+ if err != nil {
+ t.Fatalf("could not set extended headers state: %s", err)
+ }
+ eh, err := h.GetRequestExtendedHeaders()
+ if err != nil {
+ t.Fatalf("could not get extended headers state: %s", err)
+ }
+ if eh != false {
+ t.Fatalf("unexpected extended headers state")
+ }
+
err = h.SetRequestStructuredReplies(false)
if err != nil {
t.Fatalf("could not set structured replies state: %s", err)
--
2.33.1