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 _______________________________________________ Libguestfs mailing list Libguestfs@redhat.com https://listman.redhat.com/mailman/listinfo/libguestfs