The source for the easter egg example is not included, but it is: org 0x7c00 ; clear screen mov ah,0 mov al,3 int 0x10 ; print string mov ah,0x13 mov bl,0xa mov al,1 mov cx,len mov dh,0 mov dl,0 mov bp,hello int 0x10 hlt hello: db "*** Hello from nbdkit! ***",0xd,0xa len: equ $-hello ; pad to end of sector times 510-($-$$) db 0 ; boot signature db 0x55,0xaa --- configure.ac | 2 + docs/nbdkit-plugin.pod | 2 + plugins/data/nbdkit-data-plugin.pod | 1 + plugins/memory/nbdkit-memory-plugin.pod | 3 +- plugins/reflection/Makefile.am | 64 +++++ .../reflection/nbdkit-reflection-plugin.pod | 104 +++++++ plugins/reflection/reflection.c | 265 ++++++++++++++++++ tests/Makefile.am | 8 + tests/test-reflection-base64.sh | 98 +++++++ tests/test-reflection-raw.sh | 68 +++++ 10 files changed, 614 insertions(+), 1 deletion(-) diff --git a/configure.ac b/configure.ac index 4af403c..8261a7f 100644 --- a/configure.ac +++ b/configure.ac @@ -846,6 +846,7 @@ non_lang_plugins="\ partitioning \ pattern \ random \ + reflection \ split \ ssh \ streaming \ @@ -922,6 +923,7 @@ AC_CONFIG_FILES([Makefile plugins/perl/Makefile plugins/python/Makefile plugins/random/Makefile + plugins/reflection/Makefile plugins/ruby/Makefile plugins/rust/Cargo.toml plugins/rust/Makefile diff --git a/docs/nbdkit-plugin.pod b/docs/nbdkit-plugin.pod index e465410..39fa643 100644 --- a/docs/nbdkit-plugin.pod +++ b/docs/nbdkit-plugin.pod @@ -389,6 +389,8 @@ client data, be cautious when parsing it.> On error, C<nbdkit_error> is called and the call returns C<NULL>. +See also L<nbdkit-reflection-plugin(1)>. + =head1 CALLBACKS =head2 C<.name> diff --git a/plugins/data/nbdkit-data-plugin.pod b/plugins/data/nbdkit-data-plugin.pod index b0957ad..fd342b4 100644 --- a/plugins/data/nbdkit-data-plugin.pod +++ b/plugins/data/nbdkit-data-plugin.pod @@ -240,6 +240,7 @@ L<nbdkit-null-plugin(1)>, L<nbdkit-partitioning-plugin(1)>, L<nbdkit-pattern-plugin(1)>, L<nbdkit-random-plugin(1)>, +L<nbdkit-reflection-plugin(1)>, L<nbdkit-zero-plugin(1)>, L<https://github.com/libguestfs/nbdkit/blob/master/plugins/data/disk2d...;, L<https://en.wikipedia.org/wiki/Base64>;. diff --git a/plugins/memory/nbdkit-memory-plugin.pod b/plugins/memory/nbdkit-memory-plugin.pod index 76824d6..4503651 100644 --- a/plugins/memory/nbdkit-memory-plugin.pod +++ b/plugins/memory/nbdkit-memory-plugin.pod @@ -86,7 +86,8 @@ L<nbdkit(1)>, L<nbdkit-plugin(3)>, L<nbdkit-loop(1)>, L<nbdkit-data-plugin(1)>, -L<nbdkit-file-plugin(1)>. +L<nbdkit-file-plugin(1)>, +L<nbdkit-reflection-plugin(1)>. =head1 AUTHORS diff --git a/plugins/reflection/Makefile.am b/plugins/reflection/Makefile.am new file mode 100644 index 0000000..40aa786 --- /dev/null +++ b/plugins/reflection/Makefile.am @@ -0,0 +1,64 @@ +# nbdkit +# Copyright (C) 2017-2019 Red Hat Inc. +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions are +# met: +# +# * Redistributions of source code must retain the above copyright +# notice, this list of conditions and the following disclaimer. +# +# * Redistributions in binary form must reproduce the above copyright +# notice, this list of conditions and the following disclaimer in the +# documentation and/or other materials provided with the distribution. +# +# * Neither the name of Red Hat nor the names of its contributors may be +# used to endorse or promote products derived from this software without +# specific prior written permission. +# +# THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND +# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, +# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A +# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR +# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF +# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND +# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, +# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT +# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +# SUCH DAMAGE. + +include $(top_srcdir)/common-rules.mk + +EXTRA_DIST = nbdkit-reflection-plugin.pod + +plugin_LTLIBRARIES = nbdkit-reflection-plugin.la + +nbdkit_reflection_plugin_la_SOURCES = \ + reflection.c \ + $(top_srcdir)/include/nbdkit-plugin.h \ + $(NULL) + +nbdkit_reflection_plugin_la_CPPFLAGS = \ + -I$(top_srcdir)/include \ + $(NULL) +nbdkit_reflection_plugin_la_CFLAGS = $(WARNINGS_CFLAGS) +nbdkit_reflection_plugin_la_LDFLAGS = \ + -module -avoid-version -shared \ + -Wl,--version-script=$(top_srcdir)/plugins/plugins.syms \ + $(NULL) +nbdkit_reflection_plugin_la_LIBADD = \ + $(NULL) + +if HAVE_POD + +man_MANS = nbdkit-reflection-plugin.1 +CLEANFILES += $(man_MANS) + +nbdkit-reflection-plugin.1: nbdkit-reflection-plugin.pod + $(PODWRAPPER) --section=1 --man $@ \ + --html $(top_builddir)/html/$@.html \ + $< + +endif HAVE_POD diff --git a/plugins/reflection/nbdkit-reflection-plugin.pod b/plugins/reflection/nbdkit-reflection-plugin.pod new file mode 100644 index 0000000..1b260b6 --- /dev/null +++ b/plugins/reflection/nbdkit-reflection-plugin.pod @@ -0,0 +1,104 @@ +=head1 NAME + +nbdkit-reflection-plugin - reflect export name back to the client + +=head1 SYNOPSIS + + nbdkit reflection [mode=]exportname|base64exportname + +=head1 DESCRIPTION + +C<nbdkit-reflection-plugin> is a test plugin which reflects +information sent by the client back to the client. + +In its default mode (C<mode=exportname>) it converts the export name +passed from the client into a disk image. C<mode=base64exportname> is +similar except the client must base64-encode the data in the export +name, allowing arbitrary binary data to be sent (see L</EXAMPLES> +below to make this clearer). + +The plugin only supports read-only access. To make the disk writable, +add L<nbdkit-cow-filter(1)> on top. + +=head1 EXAMPLES + +Create a reflection disk. By setting the export name to C<"hello"> +when we open it, a virtual disk of only 5 bytes containing these +characters is created. We then display the contents: + + $ nbdkit reflection mode=exportname + $ nbdsh -u 'nbd://localhost/hello' -c - <<'EOF' + size = h.get_size() + print("size = %d" % size) + buf = h.pread(size, 0) + print("buf = %r" % buf) + EOF + + size = 5 + buf = b"hello" + +By running a reflection plugin, you can pass whole bootable VMs on the +qemu command line: + + $ nbdkit reflection mode=base64exportname + $ qemu-system-x86_64 \ + -drive 'snapshot=on,file.driver=nbd,file.host=localhost,file.port=10809,file.export= + tACwA80QtBOzCrABuRwAtgCyAL0ZfM0Q9CoqKiBIZWxsbyBmcm9tIG5iZGtp + dCEgKioqDQoAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA + AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA + AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA + AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA + AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA + AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA + AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA + AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA + AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA + AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA + AAAAAAAAAAAAAAAAAAAAVao= + ' + +=head1 PARAMETERS + +=over 4 + +=item [B<mode=>]B<base64exportname> + +Reflect the export name passed by the client, assuming the client +string is base64 encoded. + +This mode is only supported if nbdkit was compiled with GnuTLS E<ge> +3.6.0. You can find out by checking if: + + $ nbdkit reflection --dump-plugin + +contains: + + reflection_base64=yes + +=item [B<mode=>]B<exportname> + +Reflect the raw export name passed by the client. Note the export +name cannot contain ASCII NUL characters. + +This is the default mode. + +C<mode=> is a magic config key and may be omitted in most cases. +See L<nbdkit(1)/Magic parameters>. + +=back + +=head1 SEE ALSO + +L<nbdkit(1)>, +L<nbdkit-plugin(3)>, +L<nbdkit-cow-filter(1)>, +L<nbdkit-data-plugin(1)>, +L<nbdkit-memory-plugin(1)/Preloading small amounts of data>. + +=head1 AUTHORS + +Richard W.M. Jones + +=head1 COPYRIGHT + +Copyright (C) 2019 Red Hat Inc. diff --git a/plugins/reflection/reflection.c b/plugins/reflection/reflection.c new file mode 100644 index 0000000..74f7169 --- /dev/null +++ b/plugins/reflection/reflection.c @@ -0,0 +1,265 @@ +/* nbdkit + * Copyright (C) 2017-2019 Red Hat Inc. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * * Neither the name of Red Hat nor the names of its contributors may be + * used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, + * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A + * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF + * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <config.h> + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#if defined(HAVE_GNUTLS) && defined(HAVE_GNUTLS_BASE64_DECODE2) +#include <gnutls/gnutls.h> +#define HAVE_BASE64 1 +#endif + +#define NBDKIT_API_VERSION 2 + +#include <nbdkit-plugin.h> + +/* The mode. */ +enum mode { + MODE_EXPORTNAME, + MODE_BASE64EXPORTNAME, +}; +static enum mode mode = MODE_EXPORTNAME; + +static int +reflection_config (const char *key, const char *value) +{ + if (strcmp (key, "mode") == 0) { + if (strcasecmp (value, "exportname") == 0) { + mode = MODE_EXPORTNAME; + } + else if (strcasecmp (value, "base64exportname") == 0) { +#ifdef HAVE_BASE64 + mode = MODE_BASE64EXPORTNAME; +#else + nbdkit_error ("the plugin was compiled without base64 support"); + return -1; +#endif + } + else { + nbdkit_error ("unknown mode: '%s'", value); + return -1; + } + } + else { + nbdkit_error ("unknown parameter '%s'", key); + return -1; + } + + return 0; +} + +#define reflection_config_help \ + "mode=MODE Plugin mode." + +/* Provide a way to detect if the base64 feature is supported. */ +static void +reflection_dump_plugin (void) +{ +#ifdef HAVE_BASE64 + printf ("reflection_base64=yes\n"); +#endif +} + +/* Per-connection handle. */ +struct handle { + void *data; /* Block device data. */ + size_t len; /* Length of data in bytes. */ +}; + +static int +decode_base64 (const char *data, size_t len, struct handle *ret) +{ +#ifdef HAVE_BASE64 + gnutls_datum_t in, out; + int err; + + /* For unclear reasons gnutls_base64_decode2 won't handle an empty + * string, even though base64("") == "". + * https://tools.ietf.org/html/rfc4648#section-10 + * https://gitlab.com/gnutls/gnutls/issues/834 + * So we have to special-case it. + */ + if (len == 0) { + ret->data = NULL; + ret->len = 0; + return 0; + } + + in.data = (unsigned char *) data; + in.size = len; + err = gnutls_base64_decode2 (&in, &out); + if (err != GNUTLS_E_SUCCESS) { + nbdkit_error ("base64: %s", gnutls_strerror (err)); + /* We don't have to free out.data. I verified that it is freed on + * the error path of gnutls_base64_decode2. + */ + return -1; + } + + ret->data = out.data; /* caller frees, eventually */ + ret->len = out.size; + return 0; +#else + nbdkit_error ("the plugin was compiled without base64 support"); + return -1; +#endif +} + +/* Create the per-connection handle. + * + * This is a rather unusual plugin because it has to parse data sent + * by the client. For security reasons, be careful about: + * + * - Returning more data than is sent by the client. + * + * - Inputs that result in unbounded output. + * + * - Inputs that could hang, crash or exploit the server. + */ +static void * +reflection_open (int readonly) +{ + const char *export_name; + size_t export_name_len; + struct handle *h; + + h = malloc (sizeof *h); + if (h == NULL) { + nbdkit_error ("malloc: %m"); + return NULL; + } + + switch (mode) { + case MODE_EXPORTNAME: + case MODE_BASE64EXPORTNAME: + export_name = nbdkit_export_name (); + if (export_name == NULL) { + free (h); + return NULL; + } + export_name_len = strlen (export_name); + + if (mode == MODE_EXPORTNAME) { + h->len = export_name_len; + h->data = strdup (export_name); + if (h->data == NULL) { + nbdkit_error ("strdup: %m"); + free (h); + return NULL; + } + return h; + } + else /* mode == MODE_BASE64EXPORTNAME */ { + if (decode_base64 (export_name, export_name_len, h) == -1) { + free (h); + return NULL; + } + return h; + } + + default: + abort (); + } +} + +/* Close the per-connection handle. */ +static void +reflection_close (void *handle) +{ + struct handle *h = handle; + + free (h->data); + free (h); +} + +#define THREAD_MODEL NBDKIT_THREAD_MODEL_PARALLEL + +/* Get the disk size. */ +static int64_t +reflection_get_size (void *handle) +{ + struct handle *h = handle; + + return (int64_t) h->len; +} + +/* Read-only plugin so multi-conn is safe. */ +static int +reflection_can_multi_conn (void *handle) +{ + return 1; +} + +/* Cache. */ +static int +reflection_can_cache (void *handle) +{ + /* Everything is already in memory, returning this without + * implementing .cache lets nbdkit do the correct no-op. + */ + return NBDKIT_CACHE_NATIVE; +} + +/* Read data. */ +static int +reflection_pread (void *handle, void *buf, uint32_t count, uint64_t offset, + uint32_t flags) +{ + struct handle *h = handle; + + memcpy (buf, h->data + offset, count); + return 0; +} + +static struct nbdkit_plugin plugin = { + .name = "reflection", + .version = PACKAGE_VERSION, + .config = reflection_config, + .config_help = reflection_config_help, + .dump_plugin = reflection_dump_plugin, + .magic_config_key = "mode", + .open = reflection_open, + .close = reflection_close, + .get_size = reflection_get_size, + .can_multi_conn = reflection_can_multi_conn, + .can_cache = reflection_can_cache, + .pread = reflection_pread, + /* In this plugin, errno is preserved properly along error return + * paths from failed system calls. + */ + .errno_is_preserved = 1, +}; + +NBDKIT_REGISTER_PLUGIN(plugin) diff --git a/tests/Makefile.am b/tests/Makefile.am index 9eec75e..69d5d5e 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -111,6 +111,8 @@ EXTRA_DIST = \ test-rate-dynamic.sh \ test.rb \ test-readahead-copy.sh \ + test-reflection-base64.sh \ + test-reflection-raw.sh \ test-shutdown.sh \ test-ssh.sh \ test.tcl \ @@ -602,6 +604,12 @@ test_random_CPPFLAGS = -I $(top_srcdir)/common/include test_random_CFLAGS = $(WARNINGS_CFLAGS) $(LIBGUESTFS_CFLAGS) test_random_LDADD = libtest.la $(LIBGUESTFS_LIBS) +# reflection plugin test. +TESTS += \ + test-reflection-base64.sh \ + test-reflection-raw.sh \ + $(NULL) + # split files plugin test. check_DATA += split1 split2 split3 CLEANFILES += split1 split2 split3 diff --git a/tests/test-reflection-base64.sh b/tests/test-reflection-base64.sh new file mode 100755 index 0000000..cf21bf0 --- /dev/null +++ b/tests/test-reflection-base64.sh @@ -0,0 +1,98 @@ +#!/usr/bin/env bash +# nbdkit +# Copyright (C) 2018-2019 Red Hat Inc. +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions are +# met: +# +# * Redistributions of source code must retain the above copyright +# notice, this list of conditions and the following disclaimer. +# +# * Redistributions in binary form must reproduce the above copyright +# notice, this list of conditions and the following disclaimer in the +# documentation and/or other materials provided with the distribution. +# +# * Neither the name of Red Hat nor the names of its contributors may be +# used to endorse or promote products derived from this software without +# specific prior written permission. +# +# THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND +# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, +# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A +# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR +# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF +# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND +# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, +# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT +# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +# SUCH DAMAGE. + +# Test the relection plugin with base64-encoded export name. + +source ./functions.sh +set -e +set -x + +requires nbdsh --version +# XXX This needs to test $PYTHON somehow. +#requires python -c 'import base64' + +# Test if mode=base64exportname is supported in this build. +if ! nbdkit reflection --dump-plugin | grep -sq "reflection_base64=yes"; then + echo "$0: mode=base64exportname is not supported in this build" + exit 77 +fi + +sock=`mktemp -u` +files="reflection-base64.out reflection-base64.pid $sock" +rm -f $files +cleanup_fn rm -f $files + +# Run nbdkit. +start_nbdkit -P reflection-base64.pid -U $sock \ + reflection mode=base64exportname + +export e sock +for e in "" "test" "テスト" \ + "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" +do + nbdsh -c ' +import os +import base64 + +e = os.environ["e"] +b = base64.b64encode(e.encode("utf-8")).decode("utf-8") +print ("e = %r, b = %r" % (e,b)) +h.set_export_name (b) +h.connect_unix (os.environ["sock"]) + +size = h.get_size () +assert size == len (e.encode("utf-8")) + +# Zero-sized reads are not defined in the NBD protocol. +if size > 0: + buf = h.pread (size, 0) + assert buf == e.encode("utf-8") +' +done + +# Test that it fails if the caller passes in non-base64 data. The +# server drops the connection in this case so it's not very graceful +# but we should at least get an nbd.Error and not something else. +nbdsh -c ' +import os +import sys + +h.set_export_name ("xyz") +try: + h.connect_unix (os.environ["sock"]) + # This should not happen. + sys.exit (1) +except nbd.Error as ex: + sys.exit (0) +# This should not happen. +sys.exit (1) +' diff --git a/tests/test-reflection-raw.sh b/tests/test-reflection-raw.sh new file mode 100755 index 0000000..675e316 --- /dev/null +++ b/tests/test-reflection-raw.sh @@ -0,0 +1,68 @@ +#!/usr/bin/env bash +# nbdkit +# Copyright (C) 2018-2019 Red Hat Inc. +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions are +# met: +# +# * Redistributions of source code must retain the above copyright +# notice, this list of conditions and the following disclaimer. +# +# * Redistributions in binary form must reproduce the above copyright +# notice, this list of conditions and the following disclaimer in the +# documentation and/or other materials provided with the distribution. +# +# * Neither the name of Red Hat nor the names of its contributors may be +# used to endorse or promote products derived from this software without +# specific prior written permission. +# +# THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND +# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, +# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A +# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR +# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF +# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND +# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, +# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT +# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +# SUCH DAMAGE. + +# Test the relection plugin with raw export name. + +source ./functions.sh +set -e +set -x + +requires nbdsh --version + +sock=`mktemp -u` +files="reflection-raw.out reflection-raw.pid $sock" +rm -f $files +cleanup_fn rm -f $files + +# Run nbdkit. +start_nbdkit -P reflection-raw.pid -U $sock reflection + +for e in "" "test" "テスト" \ + "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" +do + export e sock + nbdsh -c ' +import os + +e = os.environ["e"] +h.set_export_name (e) +h.connect_unix (os.environ["sock"]) + +size = h.get_size () +assert size == len (e.encode("utf-8")) + +# Zero-sized reads are not defined in the NBD protocol. +if size > 0: + buf = h.pread (size, 0) + assert buf == e.encode("utf-8") +' +done -- 2.23.0

On 9/15/19 9:55 AM, Richard W.M. Jones wrote: Yes, you now have more justification for why a .connect would be a useful callback (and we would document that the plugin is responsible for NOT sticking a lot of code into .connect, so that it does not become an amplification attack). You need to call nbdkit_error() if getpeername() returns -1 Otherwise, looks reasonable. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org

On 9/15/19 9:55 AM, Richard W.M. Jones wrote: Short commit message; at a minimum, I'd probably at least mention that we thought about potential security issues, and didn't see how it could be abused. Could perhaps squash this hunk into patch 1, but it's also fine here. Do we want a mode that attempts to do DNS lookup to convert an address back to a name, so that this could result in b'localhost:58912'? missing 'is' reflection (hmm, I missed that typo in patch 1, where this was copied from) Is it worth also trying to test a TCP socket (although we have to worry about finding a free port for the server, as well as heavily filtering the result as it might be [::1] or 127.0.0.1, and most certainly will have a different client port number per test run. But overall, I think this is a useful thing to add to the plugin, and I'm not seeing any security holes in letting the client know the client's IP address as seen by the server. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org

On 9/15/19 10:04 AM, Richard W.M. Jones wrote: Correct - any two simultaneous clients over TCP will necessarily have different content even if they have requested the same export name, so you do need this patch squashed in. Unix sockets (currently) get the same content, but it's not worth trying to distinguish TCP vs. Unix sockets here. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org