* [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21
@ 2019-01-21 22:48 Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 01/21] iotests: Make 233 output more reliable Eric Blake
` (21 more replies)
0 siblings, 22 replies; 23+ messages in thread
From: Eric Blake @ 2019-01-21 22:48 UTC (permalink / raw)
To: qemu-devel
The following changes since commit 166609e6070fab3424510ac7292ecb585f8b80fb:
Merge remote-tracking branch 'remotes/amarkovic/tags/mips-queue-january-17-2019-v2' into staging (2019-01-21 17:53:28 +0000)
are available in the Git repository at:
https://repo.or.cz/qemu/ericb.git tags/pull-nbd-2019-01-21
for you to fetch changes up to ddd09448fd833d646952c769ae9ce3d39bee989f:
iotests: Enhance 223, 233 to cover 'qemu-nbd --list' (2019-01-21 15:49:52 -0600)
----------------------------------------------------------------
nbd patches for 2019-01-21
Add 'qemu-nbd --list' for probing a remote NBD server's advertisements.
- Eric Blake: 0/21 nbd: add qemu-nbd --list
----------------------------------------------------------------
Eric Blake (21):
iotests: Make 233 output more reliable
maint: Allow for EXAMPLES in texi2pod
qemu-nbd: Enhance man page
qemu-nbd: Sanity check partition bounds
nbd/server: Hoist length check to qmp_nbd_server_add
nbd/server: Favor [u]int64_t over off_t
qemu-nbd: Avoid strtol open-coding
nbd/client: Refactor nbd_receive_list()
nbd/client: Move export name into NBDExportInfo
nbd/client: Change signature of nbd_negotiate_simple_meta_context()
nbd/client: Split out nbd_send_meta_query()
nbd/client: Split out nbd_receive_one_meta_context()
nbd/client: Refactor return of nbd_receive_negotiate()
nbd/client: Split handshake into two functions
nbd/client: Pull out oldstyle size determination
nbd/client: Refactor nbd_opt_go() to support NBD_OPT_INFO
nbd/client: Add nbd_receive_export_list()
nbd/client: Add meta contexts to nbd_receive_export_list()
qemu-nbd: Add --list option
nbd/client: Work around 3.0 bug for listing meta contexts
iotests: Enhance 223, 233 to cover 'qemu-nbd --list'
qemu-nbd.texi | 119 +++++--
Makefile | 2 +
include/block/nbd.h | 31 +-
block/nbd-client.c | 9 +-
blockdev-nbd.c | 10 +-
nbd/client.c | 775 ++++++++++++++++++++++++++++++++-------------
nbd/server.c | 24 +-
qemu-nbd.c | 224 ++++++++++---
nbd/trace-events | 17 +-
scripts/texi2pod.pl | 2 +-
tests/qemu-iotests/223 | 2 +
tests/qemu-iotests/223.out | 20 ++
tests/qemu-iotests/233 | 30 +-
tests/qemu-iotests/233.out | 19 +-
14 files changed, 945 insertions(+), 339 deletions(-)
--
2.20.1
^ permalink raw reply [flat|nested] 23+ messages in thread
* [Qemu-devel] [PULL 01/21] iotests: Make 233 output more reliable
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
@ 2019-01-21 22:48 ` Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 02/21] maint: Allow for EXAMPLES in texi2pod Eric Blake
` (20 subsequent siblings)
21 siblings, 0 replies; 23+ messages in thread
From: Eric Blake @ 2019-01-21 22:48 UTC (permalink / raw)
To: qemu-devel
Cc: Daniel P . Berrangé,
Kevin Wolf, Max Reitz, open list:Block layer core
We have a race between the nbd server and the client both trying
to report errors at once which can make the test sometimes fail
if the output lines swap order under load. Break the race by
collecting server messages into a file and then replaying that
at the end of the test.
We may yet want to fix the server to not output ANYTHING for a
client action except when -v was used (to avoid malicious clients
from being able to DoS a server by filling up its logs), but that
is saved for a future patch.
Signed-off-by: Eric Blake <eblake@redhat.com>
CC: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20190117193658.16413-2-eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
---
tests/qemu-iotests/233 | 11 ++++++++---
tests/qemu-iotests/233.out | 4 +++-
2 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/tests/qemu-iotests/233 b/tests/qemu-iotests/233
index 1814efe3333..ab15c777370 100755
--- a/tests/qemu-iotests/233
+++ b/tests/qemu-iotests/233
@@ -2,7 +2,7 @@
#
# Test NBD TLS certificate / authorization integration
#
-# Copyright (C) 2018 Red Hat, Inc.
+# Copyright (C) 2018-2019 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
@@ -30,6 +30,7 @@ _cleanup()
{
nbd_server_stop
_cleanup_test_img
+ rm -f "$TEST_DIR/server.log"
tls_x509_cleanup
}
trap "_cleanup; exit \$status" 0 1 2 3 15
@@ -66,7 +67,7 @@ $QEMU_IO -c 'w -P 0x11 1m 1m' "$TEST_IMG" | _filter_qemu_io
echo
echo "== check TLS client to plain server fails =="
-nbd_server_start_tcp_socket -f $IMGFMT "$TEST_IMG"
+nbd_server_start_tcp_socket -f $IMGFMT "$TEST_IMG" 2> "$TEST_DIR/server.log"
$QEMU_IMG info --image-opts \
--object tls-creds-x509,dir=${tls_dir}/client1,endpoint=client,id=tls0 \
@@ -81,7 +82,7 @@ echo "== check plain client to TLS server fails =="
nbd_server_start_tcp_socket \
--object tls-creds-x509,dir=${tls_dir}/server1,endpoint=server,id=tls0,verify-peer=yes \
--tls-creds tls0 \
- -f $IMGFMT "$TEST_IMG"
+ -f $IMGFMT "$TEST_IMG" 2>> "$TEST_DIR/server.log"
$QEMU_IMG info nbd://localhost:$nbd_tcp_port 2>&1 | sed "s/$nbd_tcp_port/PORT/g"
@@ -109,6 +110,10 @@ $QEMU_IO -c 'r -P 0x11 1m 1m' -c 'w -P 0x22 1m 1m' --image-opts \
$QEMU_IO -f $IMGFMT -r -U -c 'r -P 0x22 1m 1m' "$TEST_IMG" | _filter_qemu_io
+echo
+echo "== final server log =="
+cat "$TEST_DIR/server.log"
+
# success, all done
echo "*** done"
rm -f $seq.full
diff --git a/tests/qemu-iotests/233.out b/tests/qemu-iotests/233.out
index 5f416721b03..2199d8a8b32 100644
--- a/tests/qemu-iotests/233.out
+++ b/tests/qemu-iotests/233.out
@@ -27,7 +27,6 @@ virtual size: 64M (67108864 bytes)
disk size: unavailable
== check TLS with different CA fails ==
-qemu-nbd: option negotiation failed: Verify failed: No certificate was found.
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
== perform I/O over TLS ==
@@ -37,4 +36,7 @@ wrote 1048576/1048576 bytes at offset 1048576
1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
read 1048576/1048576 bytes at offset 1048576
1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== final server log ==
+qemu-nbd: option negotiation failed: Verify failed: No certificate was found.
*** done
--
2.20.1
^ permalink raw reply related [flat|nested] 23+ messages in thread
* [Qemu-devel] [PULL 02/21] maint: Allow for EXAMPLES in texi2pod
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 01/21] iotests: Make 233 output more reliable Eric Blake
@ 2019-01-21 22:48 ` Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 03/21] qemu-nbd: Enhance man page Eric Blake
` (19 subsequent siblings)
21 siblings, 0 replies; 23+ messages in thread
From: Eric Blake @ 2019-01-21 22:48 UTC (permalink / raw)
To: qemu-devel; +Cc: Richard W . M . Jones, Vladimir Sementsov-Ogievskiy
The next commit will add an EXAMPLES section to qemu-nbd.8;
for that to work, we need to recognize EXAMPLES in texi2pod.
We also need to add a dependency from all man pages against
the generator script, since a change to the generator may
cause the resulting man page to differ.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Message-Id: <20190117193658.16413-3-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
Makefile | 2 ++
scripts/texi2pod.pl | 2 +-
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/Makefile b/Makefile
index dccba1dca27..2639437cdaf 100644
--- a/Makefile
+++ b/Makefile
@@ -858,6 +858,8 @@ docs/interop/qemu-qmp-ref.dvi docs/interop/qemu-qmp-ref.html \
docs/interop/qemu-qmp-ref.txt docs/interop/qemu-qmp-ref.7: \
docs/interop/qemu-qmp-ref.texi docs/interop/qemu-qmp-qapi.texi
+$(filter %.1 %.7 %.8,$(DOCS)): scripts/texi2pod.pl
+
# Reports/Analysis
%/coverage-report.html:
diff --git a/scripts/texi2pod.pl b/scripts/texi2pod.pl
index 39ce584a322..839b7917cf7 100755
--- a/scripts/texi2pod.pl
+++ b/scripts/texi2pod.pl
@@ -398,7 +398,7 @@ $sects{NAME} = "$fn \- $tl\n";
$sects{FOOTNOTES} .= "=back\n" if exists $sects{FOOTNOTES};
for $sect (qw(NAME SYNOPSIS DESCRIPTION OPTIONS ENVIRONMENT FILES
- BUGS NOTES FOOTNOTES SEEALSO AUTHOR COPYRIGHT)) {
+ BUGS NOTES FOOTNOTES EXAMPLES SEEALSO AUTHOR COPYRIGHT)) {
if(exists $sects{$sect}) {
$head = $sect;
$head =~ s/SEEALSO/SEE ALSO/;
--
2.20.1
^ permalink raw reply related [flat|nested] 23+ messages in thread
* [Qemu-devel] [PULL 03/21] qemu-nbd: Enhance man page
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 01/21] iotests: Make 233 output more reliable Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 02/21] maint: Allow for EXAMPLES in texi2pod Eric Blake
@ 2019-01-21 22:48 ` Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 04/21] qemu-nbd: Sanity check partition bounds Eric Blake
` (18 subsequent siblings)
21 siblings, 0 replies; 23+ messages in thread
From: Eric Blake @ 2019-01-21 22:48 UTC (permalink / raw)
To: qemu-devel
Cc: Richard W . M . Jones, Vladimir Sementsov-Ogievskiy,
open list:Network Block Dev...
Document some useful qemu-nbd command lines. Mention some restrictions
on particular options, like -p being only for MBR images, or -c/-d
being Linux-only. Update some text given the recent change to no
longer serve oldstyle protocol (missed in commit 7f7dfe2a). Also,
consistently use trailing '.' in describing options.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Message-Id: <20190117193658.16413-4-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
qemu-nbd.texi | 94 ++++++++++++++++++++++++++++++++++++++++-----------
1 file changed, 75 insertions(+), 19 deletions(-)
diff --git a/qemu-nbd.texi b/qemu-nbd.texi
index 96b1546006a..f218291bf30 100644
--- a/qemu-nbd.texi
+++ b/qemu-nbd.texi
@@ -10,11 +10,17 @@
Export a QEMU disk image using the NBD protocol.
+Other uses:
+@itemize
+@item
+Bind a /dev/nbdX block device to a QEMU server (on Linux).
+@end itemize
+
@c man end
@c man begin OPTIONS
@var{filename} is a disk image filename, or a set of block
-driver options if @var{--image-opts} is specified.
+driver options if @option{--image-opts} is specified.
@var{dev} is an NBD device.
@@ -27,24 +33,25 @@ supported. The common object types that it makes sense to define are the
keys, and the @code{tls-creds} object, which is used to supply TLS
credentials for the qemu-nbd server.
@item -p, --port=@var{port}
-The TCP port to listen on (default @samp{10809})
+The TCP port to listen on (default @samp{10809}).
@item -o, --offset=@var{offset}
-The offset into the image
+The offset into the image.
@item -b, --bind=@var{iface}
-The interface to bind to (default @samp{0.0.0.0})
+The interface to bind to (default @samp{0.0.0.0}).
@item -k, --socket=@var{path}
-Use a unix socket with path @var{path}
+Use a unix socket with path @var{path}.
@item --image-opts
Treat @var{filename} as a set of image options, instead of a plain
filename. If this flag is specified, the @var{-f} flag should
not be used, instead the '@code{format=}' option should be set.
@item -f, --format=@var{fmt}
Force the use of the block driver for format @var{fmt} instead of
-auto-detecting
+auto-detecting.
@item -r, --read-only
-Export the disk as read-only
+Export the disk as read-only.
@item -P, --partition=@var{num}
-Only expose partition @var{num}
+Only expose MBR partition @var{num}. Understands physical partitions
+1-4 and logical partitions 5-8.
@item -B, --bitmap=@var{name}
If @var{filename} has a qcow2 persistent bitmap @var{name}, expose
that bitmap via the ``qemu:dirty-bitmap:@var{name}'' context
@@ -52,7 +59,7 @@ accessible through NBD_OPT_SET_META_CONTEXT.
@item -s, --snapshot
Use @var{filename} as an external snapshot, create a temporary
file with backing_file=@var{filename}, redirect the write to
-the temporary one
+the temporary one.
@item -l, --load-snapshot=@var{snapshot_param}
Load an internal snapshot inside @var{filename} and export it
as an read-only device, @var{snapshot_param} format is
@@ -76,19 +83,20 @@ driver-specific optimized zero write commands. @var{detect-zeroes} is one of
converts a zero write to an unmap operation and can only be used if
@var{discard} is set to @samp{unmap}. The default is @samp{off}.
@item -c, --connect=@var{dev}
-Connect @var{filename} to NBD device @var{dev}
+Connect @var{filename} to NBD device @var{dev} (Linux only).
@item -d, --disconnect
-Disconnect the device @var{dev}
+Disconnect the device @var{dev} (Linux only).
@item -e, --shared=@var{num}
-Allow up to @var{num} clients to share the device (default @samp{1})
+Allow up to @var{num} clients to share the device (default
+@samp{1}). Safe for readers, but for now, consistency is not
+guaranteed between multiple writers.
@item -t, --persistent
-Don't exit on the last connection
+Don't exit on the last connection.
@item -x, --export-name=@var{name}
-Set the NBD volume export name. This switches the server to use
-the new style NBD protocol negotiation
+Set the NBD volume export name (default of a zero-length string).
@item -D, --description=@var{description}
Set the NBD volume export description, as a human-readable
-string. Requires the use of @option{-x}
+string.
@item --tls-creds=ID
Enable mandatory TLS encryption for the server by setting the ID
of the TLS credentials object previously created with the --object
@@ -96,11 +104,11 @@ option.
@item --fork
Fork off the server process and exit the parent once the server is running.
@item -v, --verbose
-Display extra debugging information
+Display extra debugging information.
@item -h, --help
-Display this help and exit
+Display this help and exit.
@item -V, --version
-Display version information and exit
+Display version information and exit.
@item -T, --trace [[enable=]@var{pattern}][,events=@var{file}][,file=@var{file}]
@findex --trace
@include qemu-option-trace.texi
@@ -108,6 +116,54 @@ Display version information and exit
@c man end
+@c man begin EXAMPLES
+Start a server listening on port 10809 that exposes only the
+guest-visible contents of a qcow2 file, with no TLS encryption, and
+with the default export name (an empty string). The command is
+one-shot, and will block until the first successful client
+disconnects:
+
+@example
+qemu-nbd -f qcow2 file.qcow2
+@end example
+
+Start a long-running server listening with encryption on port 10810,
+and require clients to have a correct X.509 certificate to connect to
+a 1 megabyte subset of a raw file, using the export name 'subset':
+
+@example
+qemu-nbd \
+ --object tls-creds-x509,id=tls0,endpoint=server,dir=/path/to/qemutls \
+ --tls-creds tls0 -t -x subset -p 10810 \
+ --image-opts driver=raw,offset=1M,size=1M,file.driver=file,file.filename=file.raw
+@end example
+
+Serve a read-only copy of just the first MBR partition of a guest
+image over a Unix socket with as many as 5 simultaneous readers, with
+a persistent process forked as a daemon:
+
+@example
+qemu-nbd --fork --persistent --shared=5 --socket=/path/to/sock \
+ --partition=1 --read-only --format=qcow2 file.qcow2
+@end example
+
+Expose the guest-visible contents of a qcow2 file via a block device
+/dev/nbd0 (and possibly creating /dev/nbd0p1 and friends for
+partitions found within), then disconnect the device when done.
+Access to bind qemu-nbd to an /dev/nbd device generally requires root
+privileges, and may also require the execution of @code{modprobe nbd}
+to enable the kernel NBD client module. @emph{CAUTION}: Do not use
+this method to mount filesystems from an untrusted guest image - a
+malicious guest may have prepared the image to attempt to trigger
+kernel bugs in partition probing or file system mounting.
+
+@example
+qemu-nbd -c /dev/nbd0 -f qcow2 file.qcow2
+qemu-nbd -d /dev/nbd0
+@end example
+
+@c man end
+
@ignore
@setfilename qemu-nbd
--
2.20.1
^ permalink raw reply related [flat|nested] 23+ messages in thread
* [Qemu-devel] [PULL 04/21] qemu-nbd: Sanity check partition bounds
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
` (2 preceding siblings ...)
2019-01-21 22:48 ` [Qemu-devel] [PULL 03/21] qemu-nbd: Enhance man page Eric Blake
@ 2019-01-21 22:48 ` Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 05/21] nbd/server: Hoist length check to qmp_nbd_server_add Eric Blake
` (17 subsequent siblings)
21 siblings, 0 replies; 23+ messages in thread
From: Eric Blake @ 2019-01-21 22:48 UTC (permalink / raw)
To: qemu-devel
Cc: Vladimir Sementsov-Ogievskiy, Richard W . M . Jones,
open list:Network Block Dev...
When the user requests a partition, we were using data read
from the disk as disk offsets without a bounds check. We got
lucky that even when computed offsets are out-of-bounds,
blk_pread() will gracefully catch the error later (so I don't
think a malicious image can crash or exploit qemu-nbd, and am
not treating this as a security flaw), but it's better to
flag the problem up front than to risk permanent EIO death of
the block device down the road. The new bounds check adds
an assertion that will never fail, but rather exists to help
the compiler see that adding two positive 41-bit values
(given MBR constraints) can't overflow 64-bit off_t.
Using off_t to represent a partition length is a bit of a
misnomer; a later patch will update to saner types, but it
is left separate in case the bounds check needs to be
backported in isolation.
Also, note that the partition code blindly overwrites any
non-zero offset passed in by the user; so for now, make the
-o/-P combo an error for less confusion. In the future, we
may let -o and -P work together (selecting a subset of a
partition); so it is okay that an explicit '-o 0' behaves
no differently from omitting -o.
This can be tested with nbdkit:
$ echo hi > file
$ nbdkit -fv --filter=truncate partitioning file truncate=64k
Pre-patch:
$ qemu-nbd -p 10810 -P 1 -f raw nbd://localhost:10809 &
$ qemu-io -f raw nbd://localhost:10810
qemu-io> r -v 0 1
Disconnect client, due to: Failed to send reply: reading from file failed: Input/output error
Connection closed
read failed: Input/output error
qemu-io> q
[1]+ Done qemu-nbd -p 10810 -P 1 -f raw nbd://localhost:10809
Post-patch:
$ qemu-nbd -p 10810 -P 1 -f raw nbd://localhost:10809
qemu-nbd: Discovered partition 1 at offset 1048576 size 512, but size exceeds file length 65536
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Message-Id: <20190117193658.16413-5-eblake@redhat.com>
---
qemu-nbd.c | 22 +++++++++++++++++++++-
1 file changed, 21 insertions(+), 1 deletion(-)
diff --git a/qemu-nbd.c b/qemu-nbd.c
index 51b55f2e066..5c90c5e55f7 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -1013,12 +1013,32 @@ int main(int argc, char **argv)
fd_size -= dev_offset;
if (partition != -1) {
- ret = find_partition(blk, partition, &dev_offset, &fd_size);
+ off_t limit;
+
+ if (dev_offset) {
+ error_report("Cannot request partition and offset together");
+ exit(EXIT_FAILURE);
+ }
+ ret = find_partition(blk, partition, &dev_offset, &limit);
if (ret < 0) {
error_report("Could not find partition %d: %s", partition,
strerror(-ret));
exit(EXIT_FAILURE);
}
+ /*
+ * MBR partition limits are (32-bit << 9); this assert lets
+ * the compiler know that we have two positive values that
+ * can't overflow 64 bits.
+ */
+ assert(dev_offset >= 0 && dev_offset + limit >= dev_offset);
+ if (dev_offset + limit > fd_size) {
+ error_report("Discovered partition %d at offset %lld size %lld, "
+ "but size exceeds file length %lld", partition,
+ (long long int) dev_offset, (long long int) limit,
+ (long long int) fd_size);
+ exit(EXIT_FAILURE);
+ }
+ fd_size = limit;
}
export = nbd_export_new(bs, dev_offset, fd_size, export_name,
--
2.20.1
^ permalink raw reply related [flat|nested] 23+ messages in thread
* [Qemu-devel] [PULL 05/21] nbd/server: Hoist length check to qmp_nbd_server_add
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
` (3 preceding siblings ...)
2019-01-21 22:48 ` [Qemu-devel] [PULL 04/21] qemu-nbd: Sanity check partition bounds Eric Blake
@ 2019-01-21 22:48 ` Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 06/21] nbd/server: Favor [u]int64_t over off_t Eric Blake
` (16 subsequent siblings)
21 siblings, 0 replies; 23+ messages in thread
From: Eric Blake @ 2019-01-21 22:48 UTC (permalink / raw)
To: qemu-devel
Cc: Vladimir Sementsov-Ogievskiy, Kevin Wolf, Max Reitz,
open list:Block layer core
We only had two callers to nbd_export_new; qemu-nbd.c always
passed a valid offset/length pair (because it already checked
the file length, to ensure that offset was in bounds), while
blockdev-nbd.c always passed 0/-1. Then nbd_export_new reduces
the size to a multiple of BDRV_SECTOR_SIZE (can only happen
when offset is not sector-aligned, since bdrv_getlength()
currently rounds up) (someday, it would be nice to have
byte-accurate lengths - but not today).
However, I'm finding it easier to work with the code if we are
consistent on having both callers pass in a valid length, and
just assert that things are sane in nbd_export_new, meaning
that no negative values were passed, and that offset+size does
not exceed 63 bits (as that really is a fundamental limit to
later operations, whether we use off_t or uint64_t).
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190117193658.16413-6-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
blockdev-nbd.c | 10 +++++++++-
nbd/server.c | 10 +++-------
2 files changed, 12 insertions(+), 8 deletions(-)
diff --git a/blockdev-nbd.c b/blockdev-nbd.c
index c76d5416b90..d73ac1b026a 100644
--- a/blockdev-nbd.c
+++ b/blockdev-nbd.c
@@ -146,6 +146,7 @@ void qmp_nbd_server_add(const char *device, bool has_name, const char *name,
BlockDriverState *bs = NULL;
BlockBackend *on_eject_blk;
NBDExport *exp;
+ int64_t len;
if (!nbd_server) {
error_setg(errp, "NBD server not running");
@@ -168,6 +169,13 @@ void qmp_nbd_server_add(const char *device, bool has_name, const char *name,
return;
}
+ len = bdrv_getlength(bs);
+ if (len < 0) {
+ error_setg_errno(errp, -len,
+ "Failed to determine the NBD export's length");
+ return;
+ }
+
if (!has_writable) {
writable = false;
}
@@ -175,7 +183,7 @@ void qmp_nbd_server_add(const char *device, bool has_name, const char *name,
writable = false;
}
- exp = nbd_export_new(bs, 0, -1, name, NULL, bitmap,
+ exp = nbd_export_new(bs, 0, len, name, NULL, bitmap,
writable ? 0 : NBD_FLAG_READ_ONLY,
NULL, false, on_eject_blk, errp);
if (!exp) {
diff --git a/nbd/server.c b/nbd/server.c
index 6b136019f82..51ee8094e02 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -1495,17 +1495,13 @@ NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
exp->refcount = 1;
QTAILQ_INIT(&exp->clients);
exp->blk = blk;
+ assert(dev_offset >= 0 && dev_offset <= INT64_MAX);
exp->dev_offset = dev_offset;
exp->name = g_strdup(name);
exp->description = g_strdup(description);
exp->nbdflags = nbdflags;
- exp->size = size < 0 ? blk_getlength(blk) : size;
- if (exp->size < 0) {
- error_setg_errno(errp, -exp->size,
- "Failed to determine the NBD export's length");
- goto fail;
- }
- exp->size -= exp->size % BDRV_SECTOR_SIZE;
+ assert(size >= 0 && size <= INT64_MAX - dev_offset);
+ exp->size = QEMU_ALIGN_DOWN(size, BDRV_SECTOR_SIZE);
if (bitmap) {
BdrvDirtyBitmap *bm = NULL;
--
2.20.1
^ permalink raw reply related [flat|nested] 23+ messages in thread
* [Qemu-devel] [PULL 06/21] nbd/server: Favor [u]int64_t over off_t
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
` (4 preceding siblings ...)
2019-01-21 22:48 ` [Qemu-devel] [PULL 05/21] nbd/server: Hoist length check to qmp_nbd_server_add Eric Blake
@ 2019-01-21 22:48 ` Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 07/21] qemu-nbd: Avoid strtol open-coding Eric Blake
` (15 subsequent siblings)
21 siblings, 0 replies; 23+ messages in thread
From: Eric Blake @ 2019-01-21 22:48 UTC (permalink / raw)
To: qemu-devel
Cc: Vladimir Sementsov-Ogievskiy, Kevin Wolf, Max Reitz,
open list:Network Block Dev...
Although our compile-time environment is set up so that we always
support long files with 64-bit off_t, we have no guarantee whether
off_t is the same type as int64_t. This requires casts when
printing values, and prevents us from directly using qemu_strtoi64()
(which will be done in the next patch). Let's just flip to uint64_t
where possible, and stick to int64_t for detecting failure of
blk_getlength(); we also keep the assertions added in the previous
patch that the resulting values fit in 63 bits. The overflow check
in nbd_co_receive_request() was already sane (request->from is
validated to fit in 63 bits, and request->len is 32 bits, so the
addition can't overflow 64 bits), but rewrite it in a form easier
to recognize as a typical overflow check.
Rename the variable 'description' to keep line lengths reasonable.
Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190117193658.16413-7-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
include/block/nbd.h | 4 ++--
nbd/server.c | 18 +++++++++---------
qemu-nbd.c | 29 +++++++++++------------------
3 files changed, 22 insertions(+), 29 deletions(-)
diff --git a/include/block/nbd.h b/include/block/nbd.h
index 1971b557896..24be9570bb4 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -294,8 +294,8 @@ int nbd_errno_to_system_errno(int err);
typedef struct NBDExport NBDExport;
typedef struct NBDClient NBDClient;
-NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
- const char *name, const char *description,
+NBDExport *nbd_export_new(BlockDriverState *bs, uint64_t dev_offset,
+ uint64_t size, const char *name, const char *desc,
const char *bitmap, uint16_t nbdflags,
void (*close)(NBDExport *), bool writethrough,
BlockBackend *on_eject_blk, Error **errp);
diff --git a/nbd/server.c b/nbd/server.c
index 51ee8094e02..cb0d5634fa1 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -77,8 +77,8 @@ struct NBDExport {
BlockBackend *blk;
char *name;
char *description;
- off_t dev_offset;
- off_t size;
+ uint64_t dev_offset;
+ uint64_t size;
uint16_t nbdflags;
QTAILQ_HEAD(, NBDClient) clients;
QTAILQ_ENTRY(NBDExport) next;
@@ -1455,8 +1455,8 @@ static void nbd_eject_notifier(Notifier *n, void *data)
nbd_export_close(exp);
}
-NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
- const char *name, const char *description,
+NBDExport *nbd_export_new(BlockDriverState *bs, uint64_t dev_offset,
+ uint64_t size, const char *name, const char *desc,
const char *bitmap, uint16_t nbdflags,
void (*close)(NBDExport *), bool writethrough,
BlockBackend *on_eject_blk, Error **errp)
@@ -1495,12 +1495,12 @@ NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
exp->refcount = 1;
QTAILQ_INIT(&exp->clients);
exp->blk = blk;
- assert(dev_offset >= 0 && dev_offset <= INT64_MAX);
+ assert(dev_offset <= INT64_MAX);
exp->dev_offset = dev_offset;
exp->name = g_strdup(name);
- exp->description = g_strdup(description);
+ exp->description = g_strdup(desc);
exp->nbdflags = nbdflags;
- assert(size >= 0 && size <= INT64_MAX - dev_offset);
+ assert(size <= INT64_MAX - dev_offset);
exp->size = QEMU_ALIGN_DOWN(size, BDRV_SECTOR_SIZE);
if (bitmap) {
@@ -2130,10 +2130,10 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request,
return -EROFS;
}
if (request->from > client->exp->size ||
- request->from + request->len > client->exp->size) {
+ request->len > client->exp->size - request->from) {
error_setg(errp, "operation past EOF; From: %" PRIu64 ", Len: %" PRIu32
", Size: %" PRIu64, request->from, request->len,
- (uint64_t)client->exp->size);
+ client->exp->size);
return (request->type == NBD_CMD_WRITE ||
request->type == NBD_CMD_WRITE_ZEROES) ? -ENOSPC : -EINVAL;
}
diff --git a/qemu-nbd.c b/qemu-nbd.c
index 5c90c5e55f7..598caa656b2 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -176,7 +176,7 @@ static void read_partition(uint8_t *p, struct partition_record *r)
}
static int find_partition(BlockBackend *blk, int partition,
- off_t *offset, off_t *size)
+ uint64_t *offset, uint64_t *size)
{
struct partition_record mbr[4];
uint8_t data[MBR_SIZE];
@@ -500,14 +500,14 @@ int main(int argc, char **argv)
{
BlockBackend *blk;
BlockDriverState *bs;
- off_t dev_offset = 0;
+ uint64_t dev_offset = 0;
uint16_t nbdflags = 0;
bool disconnect = false;
const char *bindto = NULL;
const char *port = NULL;
char *sockpath = NULL;
char *device = NULL;
- off_t fd_size;
+ int64_t fd_size;
QemuOpts *sn_opts = NULL;
const char *sn_id_or_name = NULL;
const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:D:B:";
@@ -665,10 +665,6 @@ int main(int argc, char **argv)
error_report("Invalid offset `%s'", optarg);
exit(EXIT_FAILURE);
}
- if (dev_offset < 0) {
- error_report("Offset must be positive `%s'", optarg);
- exit(EXIT_FAILURE);
- }
break;
case 'l':
if (strstart(optarg, SNAPSHOT_OPT_BASE, NULL)) {
@@ -1005,15 +1001,14 @@ int main(int argc, char **argv)
}
if (dev_offset >= fd_size) {
- error_report("Offset (%lld) has to be smaller than the image size "
- "(%lld)",
- (long long int)dev_offset, (long long int)fd_size);
+ error_report("Offset (%" PRIu64 ") has to be smaller than the image "
+ "size (%" PRId64 ")", dev_offset, fd_size);
exit(EXIT_FAILURE);
}
fd_size -= dev_offset;
if (partition != -1) {
- off_t limit;
+ uint64_t limit;
if (dev_offset) {
error_report("Cannot request partition and offset together");
@@ -1027,15 +1022,13 @@ int main(int argc, char **argv)
}
/*
* MBR partition limits are (32-bit << 9); this assert lets
- * the compiler know that we have two positive values that
- * can't overflow 64 bits.
+ * the compiler know that we can't overflow 64 bits.
*/
- assert(dev_offset >= 0 && dev_offset + limit >= dev_offset);
+ assert(dev_offset + limit >= dev_offset);
if (dev_offset + limit > fd_size) {
- error_report("Discovered partition %d at offset %lld size %lld, "
- "but size exceeds file length %lld", partition,
- (long long int) dev_offset, (long long int) limit,
- (long long int) fd_size);
+ error_report("Discovered partition %d at offset %" PRIu64
+ " size %" PRIu64 ", but size exceeds file length %"
+ PRId64, partition, dev_offset, limit, fd_size);
exit(EXIT_FAILURE);
}
fd_size = limit;
--
2.20.1
^ permalink raw reply related [flat|nested] 23+ messages in thread
* [Qemu-devel] [PULL 07/21] qemu-nbd: Avoid strtol open-coding
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
` (5 preceding siblings ...)
2019-01-21 22:48 ` [Qemu-devel] [PULL 06/21] nbd/server: Favor [u]int64_t over off_t Eric Blake
@ 2019-01-21 22:48 ` Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 08/21] nbd/client: Refactor nbd_receive_list() Eric Blake
` (14 subsequent siblings)
21 siblings, 0 replies; 23+ messages in thread
From: Eric Blake @ 2019-01-21 22:48 UTC (permalink / raw)
To: qemu-devel
Cc: Vladimir Sementsov-Ogievskiy, Richard W . M . Jones,
open list:Network Block Dev...
Our copy-and-pasted open-coding of strtol handling forgot to
handle overflow conditions. Use qemu_strto*() instead.
In the case of --partition, since we insist on a user-supplied
partition to be non-zero, we can use 0 rather than -1 for our
initial value to distinguish when a partition is not being
served, for slightly more optimal code.
The error messages for out-of-bounds values are less specific,
but should not be a terrible loss in quality.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Message-Id: <20190117193658.16413-8-eblake@redhat.com>
---
qemu-nbd.c | 28 +++++++++-------------------
1 file changed, 9 insertions(+), 19 deletions(-)
diff --git a/qemu-nbd.c b/qemu-nbd.c
index 598caa656b2..efca0e44a90 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -546,9 +546,8 @@ int main(int argc, char **argv)
};
int ch;
int opt_ind = 0;
- char *end;
int flags = BDRV_O_RDWR;
- int partition = -1;
+ int partition = 0;
int ret = 0;
bool seen_cache = false;
bool seen_discard = false;
@@ -660,9 +659,8 @@ int main(int argc, char **argv)
port = optarg;
break;
case 'o':
- dev_offset = strtoll (optarg, &end, 0);
- if (*end) {
- error_report("Invalid offset `%s'", optarg);
+ if (qemu_strtou64(optarg, NULL, 0, &dev_offset) < 0) {
+ error_report("Invalid offset '%s'", optarg);
exit(EXIT_FAILURE);
}
break;
@@ -684,13 +682,9 @@ int main(int argc, char **argv)
flags &= ~BDRV_O_RDWR;
break;
case 'P':
- partition = strtol(optarg, &end, 0);
- if (*end) {
- error_report("Invalid partition `%s'", optarg);
- exit(EXIT_FAILURE);
- }
- if (partition < 1 || partition > 8) {
- error_report("Invalid partition %d", partition);
+ if (qemu_strtoi(optarg, NULL, 0, &partition) < 0 ||
+ partition < 1 || partition > 8) {
+ error_report("Invalid partition '%s'", optarg);
exit(EXIT_FAILURE);
}
break;
@@ -711,15 +705,11 @@ int main(int argc, char **argv)
device = optarg;
break;
case 'e':
- shared = strtol(optarg, &end, 0);
- if (*end) {
+ if (qemu_strtoi(optarg, NULL, 0, &shared) < 0 ||
+ shared < 1) {
error_report("Invalid shared device number '%s'", optarg);
exit(EXIT_FAILURE);
}
- if (shared < 1) {
- error_report("Shared device number must be greater than 0");
- exit(EXIT_FAILURE);
- }
break;
case 'f':
fmt = optarg;
@@ -1007,7 +997,7 @@ int main(int argc, char **argv)
}
fd_size -= dev_offset;
- if (partition != -1) {
+ if (partition) {
uint64_t limit;
if (dev_offset) {
--
2.20.1
^ permalink raw reply related [flat|nested] 23+ messages in thread
* [Qemu-devel] [PULL 08/21] nbd/client: Refactor nbd_receive_list()
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
` (6 preceding siblings ...)
2019-01-21 22:48 ` [Qemu-devel] [PULL 07/21] qemu-nbd: Avoid strtol open-coding Eric Blake
@ 2019-01-21 22:48 ` Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 09/21] nbd/client: Move export name into NBDExportInfo Eric Blake
` (13 subsequent siblings)
21 siblings, 0 replies; 23+ messages in thread
From: Eric Blake @ 2019-01-21 22:48 UTC (permalink / raw)
To: qemu-devel
Cc: Richard W . M . Jones, Vladimir Sementsov-Ogievskiy,
open list:Network Block Dev...
Right now, nbd_receive_list() is only called by
nbd_receive_query_exports(), which in turn is only called if the
server lacks NBD_OPT_GO but has working option negotiation, and is
merely used as a quality-of-implementation trick since servers
can't give decent errors for NBD_OPT_EXPORT_NAME. However, servers
that lack NBD_OPT_GO are becoming increasingly rare (nbdkit was a
latecomer, in Aug 2018, but qemu has been such a server since commit
f37708f6 in July 2017 and released in 2.10), so it no longer makes
sense to micro-optimize that function for performance.
Furthermore, when debugging a server's implementation, tracing the
full reply (both names and descriptions) is useful, not to mention
that upcoming patches adding 'qemu-nbd --list' will want to collect
that data. And when you consider that a server can send an export
name up to the NBD protocol length limit of 4k; but our current
NBD_MAX_NAME_SIZE is only 256, we can't trace all valid server
names without more storage, but 4k is large enough that the heap
is better than the stack for long names.
Thus, I'm changing the division of labor, with nbd_receive_list()
now always malloc'ing a result on success (the malloc is bounded
by the fact that we reject servers with a reply length larger
than 32M), and moving the comparison to 'wantname' to the caller.
There is a minor change in behavior where a server with 0 exports
(an immediate NBD_REP_ACK reply) is now no longer distinguished
from a server without LIST support (NBD_REP_ERR_UNSUP); this
information could be preserved with a complication to the calling
contract to provide a bit more information, but I didn't see the
point. After all, the worst that can happen if our guess at a
match is wrong is that the caller will get a cryptic disconnect
when NBD_OPT_EXPORT_NAME fails (which is no different from what
would happen if we had not tried LIST), while treating an empty
list as immediate failure would prevent connecting to really old
servers that really did lack LIST. Besides, NBD servers with 0
exports are rare (qemu can do it when using QMP nbd-server-start
without nbd-server-add - but qemu understands NBD_OPT_GO and
thus won't tickle this change in behavior).
Fix the spelling of foundExport to match coding standards while
in the area.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190117193658.16413-9-eblake@redhat.com>
---
nbd/client.c | 91 ++++++++++++++++++++++++++++++------------------
nbd/trace-events | 1 +
2 files changed, 59 insertions(+), 33 deletions(-)
diff --git a/nbd/client.c b/nbd/client.c
index f625c207c54..fd4ba8dec37 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -234,18 +234,24 @@ static int nbd_handle_reply_err(QIOChannel *ioc, NBDOptionReply *reply,
return result;
}
-/* Process another portion of the NBD_OPT_LIST reply. Set *@match if
- * the current reply matches @want or if the server does not support
- * NBD_OPT_LIST, otherwise leave @match alone. Return 0 if iteration
- * is complete, positive if more replies are expected, or negative
- * with @errp set if an unrecoverable error occurred. */
-static int nbd_receive_list(QIOChannel *ioc, const char *want, bool *match,
+/* nbd_receive_list:
+ * Process another portion of the NBD_OPT_LIST reply, populating any
+ * name received into *@name. If @description is non-NULL, and the
+ * server provided a description, that is also populated. The caller
+ * must eventually call g_free() on success.
+ * Returns 1 if name and description were set and iteration must continue,
+ * 0 if iteration is complete (including if OPT_LIST unsupported),
+ * -1 with @errp set if an unrecoverable error occurred.
+ */
+static int nbd_receive_list(QIOChannel *ioc, char **name, char **description,
Error **errp)
{
+ int ret = -1;
NBDOptionReply reply;
uint32_t len;
uint32_t namelen;
- char name[NBD_MAX_NAME_SIZE + 1];
+ char *local_name = NULL;
+ char *local_desc = NULL;
int error;
if (nbd_receive_option_reply(ioc, NBD_OPT_LIST, &reply, errp) < 0) {
@@ -253,9 +259,6 @@ static int nbd_receive_list(QIOChannel *ioc, const char *want, bool *match,
}
error = nbd_handle_reply_err(ioc, &reply, errp);
if (error <= 0) {
- /* The server did not support NBD_OPT_LIST, so set *match on
- * the assumption that any name will be accepted. */
- *match = true;
return error;
}
len = reply.length;
@@ -292,33 +295,38 @@ static int nbd_receive_list(QIOChannel *ioc, const char *want, bool *match,
nbd_send_opt_abort(ioc);
return -1;
}
- if (namelen != strlen(want)) {
- if (nbd_drop(ioc, len, errp) < 0) {
- error_prepend(errp,
- "failed to skip export name with wrong length: ");
- nbd_send_opt_abort(ioc);
- return -1;
- }
- return 1;
- }
- assert(namelen < sizeof(name));
- if (nbd_read(ioc, name, namelen, errp) < 0) {
+ local_name = g_malloc(namelen + 1);
+ if (nbd_read(ioc, local_name, namelen, errp) < 0) {
error_prepend(errp, "failed to read export name: ");
nbd_send_opt_abort(ioc);
- return -1;
+ goto out;
}
- name[namelen] = '\0';
+ local_name[namelen] = '\0';
len -= namelen;
- if (nbd_drop(ioc, len, errp) < 0) {
- error_prepend(errp, "failed to read export description: ");
- nbd_send_opt_abort(ioc);
- return -1;
+ if (len) {
+ local_desc = g_malloc(len + 1);
+ if (nbd_read(ioc, local_desc, len, errp) < 0) {
+ error_prepend(errp, "failed to read export description: ");
+ nbd_send_opt_abort(ioc);
+ goto out;
+ }
+ local_desc[len] = '\0';
}
- if (!strcmp(name, want)) {
- *match = true;
+
+ trace_nbd_receive_list(local_name, local_desc ?: "");
+ *name = local_name;
+ local_name = NULL;
+ if (description) {
+ *description = local_desc;
+ local_desc = NULL;
}
- return 1;
+ ret = 1;
+
+ out:
+ g_free(local_name);
+ g_free(local_desc);
+ return ret;
}
@@ -493,7 +501,8 @@ static int nbd_receive_query_exports(QIOChannel *ioc,
const char *wantname,
Error **errp)
{
- bool foundExport = false;
+ bool list_empty = true;
+ bool found_export = false;
trace_nbd_receive_query_exports_start(wantname);
if (nbd_send_option_request(ioc, NBD_OPT_LIST, 0, NULL, errp) < 0) {
@@ -501,14 +510,25 @@ static int nbd_receive_query_exports(QIOChannel *ioc,
}
while (1) {
- int ret = nbd_receive_list(ioc, wantname, &foundExport, errp);
+ char *name;
+ int ret = nbd_receive_list(ioc, &name, NULL, errp);
if (ret < 0) {
/* Server gave unexpected reply */
return -1;
} else if (ret == 0) {
/* Done iterating. */
- if (!foundExport) {
+ if (list_empty) {
+ /*
+ * We don't have enough context to tell a server that
+ * sent an empty list apart from a server that does
+ * not support the list command; but as this function
+ * is just used to trigger a nicer error message
+ * before trying NBD_OPT_EXPORT_NAME, assume the
+ * export is available.
+ */
+ return 0;
+ } else if (!found_export) {
error_setg(errp, "No export with name '%s' available",
wantname);
nbd_send_opt_abort(ioc);
@@ -517,6 +537,11 @@ static int nbd_receive_query_exports(QIOChannel *ioc,
trace_nbd_receive_query_exports_success(wantname);
return 0;
}
+ list_empty = false;
+ if (!strcmp(name, wantname)) {
+ found_export = true;
+ }
+ g_free(name);
}
}
diff --git a/nbd/trace-events b/nbd/trace-events
index 5492042acbf..d1e1ca64ee5 100644
--- a/nbd/trace-events
+++ b/nbd/trace-events
@@ -3,6 +3,7 @@ nbd_send_option_request(uint32_t opt, const char *name, uint32_t len) "Sending o
nbd_receive_option_reply(uint32_t option, const char *optname, uint32_t type, const char *typename, uint32_t length) "Received option reply %" PRIu32" (%s), type %" PRIu32" (%s), len %" PRIu32
nbd_server_error_msg(uint32_t err, const char *type, const char *msg) "server reported error 0x%" PRIx32 " (%s) with additional message: %s"
nbd_reply_err_unsup(uint32_t option, const char *name) "server doesn't understand request %" PRIu32 " (%s), attempting fallback"
+nbd_receive_list(const char *name, const char *desc) "export list includes '%s', description '%s'"
nbd_opt_go_start(const char *name) "Attempting NBD_OPT_GO for export '%s'"
nbd_opt_go_success(void) "Export is good to go"
nbd_opt_go_info_unknown(int info, const char *name) "Ignoring unknown info %d (%s)"
--
2.20.1
^ permalink raw reply related [flat|nested] 23+ messages in thread
* [Qemu-devel] [PULL 09/21] nbd/client: Move export name into NBDExportInfo
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
` (7 preceding siblings ...)
2019-01-21 22:48 ` [Qemu-devel] [PULL 08/21] nbd/client: Refactor nbd_receive_list() Eric Blake
@ 2019-01-21 22:48 ` Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 10/21] nbd/client: Change signature of nbd_negotiate_simple_meta_context() Eric Blake
` (12 subsequent siblings)
21 siblings, 0 replies; 23+ messages in thread
From: Eric Blake @ 2019-01-21 22:48 UTC (permalink / raw)
To: qemu-devel
Cc: Richard W . M . Jones, Vladimir Sementsov-Ogievskiy, Kevin Wolf,
Max Reitz, open list:Network Block Dev...
Refactor the 'name' parameter of nbd_receive_negotiate() from
being a separate parameter into being part of the in-out 'info'.
This also spills over to a simplification of nbd_opt_go().
The main driver for this refactoring is that an upcoming patch
would like to add support to qemu-nbd to list information about
all exports available on a server, where the name(s) will be
provided by the server instead of the client. But another benefit
is that we can now allow the client to explicitly specify the
empty export name "" even when connecting to an oldstyle server
(even if qemu is no longer such a server after commit 7f7dfe2a).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190117193658.16413-10-eblake@redhat.com>
---
include/block/nbd.h | 8 ++++----
block/nbd-client.c | 5 +++--
nbd/client.c | 39 ++++++++++++++++++---------------------
qemu-nbd.c | 6 ++++--
nbd/trace-events | 2 +-
5 files changed, 30 insertions(+), 30 deletions(-)
diff --git a/include/block/nbd.h b/include/block/nbd.h
index 24be9570bb4..00d3eb57d9c 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -262,6 +262,7 @@ struct NBDExportInfo {
/* Set by client before nbd_receive_negotiate() */
bool request_sizes;
char *x_dirty_bitmap;
+ char *name; /* must be non-NULL */
/* In-out fields, set by client before nbd_receive_negotiate() and
* updated by server results during nbd_receive_negotiate() */
@@ -279,10 +280,9 @@ struct NBDExportInfo {
};
typedef struct NBDExportInfo NBDExportInfo;
-int nbd_receive_negotiate(QIOChannel *ioc, const char *name,
- QCryptoTLSCreds *tlscreds, const char *hostname,
- QIOChannel **outioc, NBDExportInfo *info,
- Error **errp);
+int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
+ const char *hostname, QIOChannel **outioc,
+ NBDExportInfo *info, Error **errp);
int nbd_init(int fd, QIOChannelSocket *sioc, NBDExportInfo *info,
Error **errp);
int nbd_send_request(QIOChannel *ioc, NBDRequest *request);
diff --git a/block/nbd-client.c b/block/nbd-client.c
index ef320759716..3309376bc16 100644
--- a/block/nbd-client.c
+++ b/block/nbd-client.c
@@ -999,10 +999,11 @@ int nbd_client_init(BlockDriverState *bs,
client->info.structured_reply = true;
client->info.base_allocation = true;
client->info.x_dirty_bitmap = g_strdup(x_dirty_bitmap);
- ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), export,
- tlscreds, hostname,
+ client->info.name = g_strdup(export ?: "");
+ ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), tlscreds, hostname,
&client->ioc, &client->info, errp);
g_free(client->info.x_dirty_bitmap);
+ g_free(client->info.name);
if (ret < 0) {
logout("Failed to negotiate with the NBD server\n");
return ret;
diff --git a/nbd/client.c b/nbd/client.c
index fd4ba8dec37..8227e69478a 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -330,15 +330,14 @@ static int nbd_receive_list(QIOChannel *ioc, char **name, char **description,
}
-/* Returns -1 if NBD_OPT_GO proves the export @wantname cannot be
+/* Returns -1 if NBD_OPT_GO proves the export @info->name cannot be
* used, 0 if NBD_OPT_GO is unsupported (fall back to NBD_OPT_LIST and
* NBD_OPT_EXPORT_NAME in that case), and > 0 if the export is good to
- * go (with @info populated). */
-static int nbd_opt_go(QIOChannel *ioc, const char *wantname,
- NBDExportInfo *info, Error **errp)
+ * go (with the rest of @info populated). */
+static int nbd_opt_go(QIOChannel *ioc, NBDExportInfo *info, Error **errp)
{
NBDOptionReply reply;
- uint32_t len = strlen(wantname);
+ uint32_t len = strlen(info->name);
uint16_t type;
int error;
char *buf;
@@ -348,10 +347,10 @@ static int nbd_opt_go(QIOChannel *ioc, const char *wantname,
* flags still 0 is a witness of a broken server. */
info->flags = 0;
- trace_nbd_opt_go_start(wantname);
+ trace_nbd_opt_go_start(info->name);
buf = g_malloc(4 + len + 2 + 2 * info->request_sizes + 1);
stl_be_p(buf, len);
- memcpy(buf + 4, wantname, len);
+ memcpy(buf + 4, info->name, len);
/* At most one request, everything else up to server */
stw_be_p(buf + 4 + len, info->request_sizes);
if (info->request_sizes) {
@@ -753,10 +752,9 @@ static int nbd_negotiate_simple_meta_context(QIOChannel *ioc,
return 0;
}
-int nbd_receive_negotiate(QIOChannel *ioc, const char *name,
- QCryptoTLSCreds *tlscreds, const char *hostname,
- QIOChannel **outioc, NBDExportInfo *info,
- Error **errp)
+int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
+ const char *hostname, QIOChannel **outioc,
+ NBDExportInfo *info, Error **errp)
{
uint64_t magic;
int rc;
@@ -766,6 +764,8 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name,
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;
rc = -EINVAL;
@@ -834,10 +834,6 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name,
goto fail;
}
}
- if (!name) {
- trace_nbd_receive_negotiate_default_name();
- name = "";
- }
if (fixedNewStyle) {
int result;
@@ -853,7 +849,8 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name,
if (info->structured_reply && base_allocation) {
result = nbd_negotiate_simple_meta_context(
- ioc, name, info->x_dirty_bitmap ?: "base:allocation",
+ ioc, info->name,
+ info->x_dirty_bitmap ?: "base:allocation",
&info->meta_base_allocation_id, errp);
if (result < 0) {
goto fail;
@@ -866,7 +863,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name,
* 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, name, info, errp);
+ result = nbd_opt_go(ioc, info, errp);
if (result < 0) {
goto fail;
}
@@ -879,12 +876,12 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name,
* query gives us better error reporting if the
* export name is not available.
*/
- if (nbd_receive_query_exports(ioc, name, errp) < 0) {
+ if (nbd_receive_query_exports(ioc, info->name, errp) < 0) {
goto fail;
}
}
/* write the export name request */
- if (nbd_send_option_request(ioc, NBD_OPT_EXPORT_NAME, -1, name,
+ if (nbd_send_option_request(ioc, NBD_OPT_EXPORT_NAME, -1, info->name,
errp) < 0) {
goto fail;
}
@@ -904,8 +901,8 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name,
} else if (magic == NBD_CLIENT_MAGIC) {
uint32_t oldflags;
- if (name) {
- error_setg(errp, "Server does not support export names");
+ if (*info->name) {
+ error_setg(errp, "Server does not support non-empty export names");
goto fail;
}
if (tlscreds) {
diff --git a/qemu-nbd.c b/qemu-nbd.c
index efca0e44a90..3c538700eae 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -264,7 +264,7 @@ static void *show_parts(void *arg)
static void *nbd_client_thread(void *arg)
{
char *device = arg;
- NBDExportInfo info = { .request_sizes = false, };
+ NBDExportInfo info = { .request_sizes = false, .name = g_strdup("") };
QIOChannelSocket *sioc;
int fd;
int ret;
@@ -279,7 +279,7 @@ static void *nbd_client_thread(void *arg)
goto out;
}
- ret = nbd_receive_negotiate(QIO_CHANNEL(sioc), NULL,
+ ret = nbd_receive_negotiate(QIO_CHANNEL(sioc),
NULL, NULL, NULL, &info, &local_error);
if (ret < 0) {
if (local_error) {
@@ -318,6 +318,7 @@ static void *nbd_client_thread(void *arg)
}
close(fd);
object_unref(OBJECT(sioc));
+ g_free(info.name);
kill(getpid(), SIGTERM);
return (void *) EXIT_SUCCESS;
@@ -326,6 +327,7 @@ out_fd:
out_socket:
object_unref(OBJECT(sioc));
out:
+ g_free(info.name);
kill(getpid(), SIGTERM);
return (void *) EXIT_FAILURE;
}
diff --git a/nbd/trace-events b/nbd/trace-events
index d1e1ca64ee5..c3966d2b653 100644
--- a/nbd/trace-events
+++ b/nbd/trace-events
@@ -17,7 +17,7 @@ nbd_opt_meta_reply(const char *context, uint32_t id) "Received mapping of contex
nbd_receive_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_default_name(void) "Using default NBD export name \"\""
+nbd_receive_negotiate_name(const char *name) "Requesting NBD export name '%s'"
nbd_receive_negotiate_size_flags(uint64_t size, uint16_t flags) "Size is %" PRIu64 ", export flags 0x%" PRIx16
nbd_init_set_socket(void) "Setting NBD socket"
nbd_init_set_block_size(unsigned long block_size) "Setting block size to %lu"
--
2.20.1
^ permalink raw reply related [flat|nested] 23+ messages in thread
* [Qemu-devel] [PULL 10/21] nbd/client: Change signature of nbd_negotiate_simple_meta_context()
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
` (8 preceding siblings ...)
2019-01-21 22:48 ` [Qemu-devel] [PULL 09/21] nbd/client: Move export name into NBDExportInfo Eric Blake
@ 2019-01-21 22:48 ` Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 11/21] nbd/client: Split out nbd_send_meta_query() Eric Blake
` (11 subsequent siblings)
21 siblings, 0 replies; 23+ messages in thread
From: Eric Blake @ 2019-01-21 22:48 UTC (permalink / raw)
To: qemu-devel
Cc: Richard W . M . Jones, Vladimir Sementsov-Ogievskiy, Kevin Wolf,
Max Reitz, open list:Network Block Dev...
Pass 'info' instead of three separate parameters related to info,
when requesting the server to set the meta context. Update the
NBDExportInfo struct to rename the received id field to match the
fact that we are currently overloading the field to match whatever
context the user supplied through the x-dirty-bitmap hack, as well
as adding a TODO comment to remind future patches about a desire
to request two contexts at once.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190117193658.16413-11-eblake@redhat.com>
---
include/block/nbd.h | 2 +-
block/nbd-client.c | 4 ++--
nbd/client.c | 53 +++++++++++++++++++++------------------------
3 files changed, 28 insertions(+), 31 deletions(-)
diff --git a/include/block/nbd.h b/include/block/nbd.h
index 00d3eb57d9c..be19aac2fc7 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -276,7 +276,7 @@ struct NBDExportInfo {
uint32_t opt_block;
uint32_t max_block;
- uint32_t meta_base_allocation_id;
+ uint32_t context_id;
};
typedef struct NBDExportInfo NBDExportInfo;
diff --git a/block/nbd-client.c b/block/nbd-client.c
index 3309376bc16..813539676d2 100644
--- a/block/nbd-client.c
+++ b/block/nbd-client.c
@@ -249,11 +249,11 @@ static int nbd_parse_blockstatus_payload(NBDClientSession *client,
}
context_id = payload_advance32(&payload);
- if (client->info.meta_base_allocation_id != context_id) {
+ if (client->info.context_id != context_id) {
error_setg(errp, "Protocol error: unexpected context id %d for "
"NBD_REPLY_TYPE_BLOCK_STATUS, when negotiated context "
"id is %d", context_id,
- client->info.meta_base_allocation_id);
+ client->info.context_id);
return -EINVAL;
}
diff --git a/nbd/client.c b/nbd/client.c
index 8227e69478a..77993890f04 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -630,26 +630,30 @@ static QIOChannel *nbd_receive_starttls(QIOChannel *ioc,
}
/* nbd_negotiate_simple_meta_context:
- * Set one meta context. Simple means that reply must contain zero (not
- * negotiated) or one (negotiated) contexts. More contexts would be considered
- * as a protocol error. It's also implied that meta-data query equals queried
- * context name, so, if server replies with something different than @context,
- * it is considered an error too.
- * return 1 for successful negotiation, context_id is set
+ * Request the server to set the meta context for export @info->name
+ * using @info->x_dirty_bitmap with a fallback to "base:allocation",
+ * setting @info->context_id to the resulting id. Fail if the server
+ * responds with more than one context or with a context different
+ * than the query.
+ * return 1 for successful negotiation,
* 0 if operation is unsupported,
* -1 with errp set for any other error
*/
static int nbd_negotiate_simple_meta_context(QIOChannel *ioc,
- const char *export,
- const char *context,
- uint32_t *context_id,
+ NBDExportInfo *info,
Error **errp)
{
+ /*
+ * TODO: Removing the x_dirty_bitmap hack will mean refactoring
+ * this function to request and store ids for multiple contexts
+ * (both base:allocation and a dirty bitmap), at which point this
+ * function should lose the term _simple.
+ */
int ret;
NBDOptionReply reply;
- uint32_t received_id = 0;
+ const char *context = info->x_dirty_bitmap ?: "base:allocation";
bool received = false;
- uint32_t export_len = strlen(export);
+ uint32_t export_len = strlen(info->name);
uint32_t context_len = strlen(context);
uint32_t data_len = sizeof(export_len) + export_len +
sizeof(uint32_t) + /* number of queries */
@@ -657,9 +661,9 @@ static int nbd_negotiate_simple_meta_context(QIOChannel *ioc,
char *data = g_malloc(data_len);
char *p = data;
- trace_nbd_opt_meta_request(context, export);
+ trace_nbd_opt_meta_request(context, info->name);
stl_be_p(p, export_len);
- memcpy(p += sizeof(export_len), export, export_len);
+ memcpy(p += sizeof(export_len), info->name, export_len);
stl_be_p(p += export_len, 1);
stl_be_p(p += sizeof(uint32_t), context_len);
memcpy(p += sizeof(context_len), context, context_len);
@@ -685,7 +689,7 @@ static int nbd_negotiate_simple_meta_context(QIOChannel *ioc,
if (reply.type == NBD_REP_META_CONTEXT) {
char *name;
- if (reply.length != sizeof(received_id) + context_len) {
+ if (reply.length != sizeof(info->context_id) + context_len) {
error_setg(errp, "Failed to negotiate meta context '%s', server "
"answered with unexpected length %" PRIu32, context,
reply.length);
@@ -693,12 +697,13 @@ static int nbd_negotiate_simple_meta_context(QIOChannel *ioc,
return -1;
}
- if (nbd_read(ioc, &received_id, sizeof(received_id), errp) < 0) {
+ if (nbd_read(ioc, &info->context_id, sizeof(info->context_id),
+ errp) < 0) {
return -1;
}
- received_id = be32_to_cpu(received_id);
+ info->context_id = be32_to_cpu(info->context_id);
- reply.length -= sizeof(received_id);
+ reply.length -= sizeof(info->context_id);
name = g_malloc(reply.length + 1);
if (nbd_read(ioc, name, reply.length, errp) < 0) {
g_free(name);
@@ -715,7 +720,7 @@ static int nbd_negotiate_simple_meta_context(QIOChannel *ioc,
}
g_free(name);
- trace_nbd_opt_meta_reply(context, received_id);
+ trace_nbd_opt_meta_reply(context, info->context_id);
received = true;
/* receive NBD_REP_ACK */
@@ -744,12 +749,7 @@ static int nbd_negotiate_simple_meta_context(QIOChannel *ioc,
return -1;
}
- if (received) {
- *context_id = received_id;
- return 1;
- }
-
- return 0;
+ return received;
}
int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
@@ -848,10 +848,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
}
if (info->structured_reply && base_allocation) {
- result = nbd_negotiate_simple_meta_context(
- ioc, info->name,
- info->x_dirty_bitmap ?: "base:allocation",
- &info->meta_base_allocation_id, errp);
+ result = nbd_negotiate_simple_meta_context(ioc, info, errp);
if (result < 0) {
goto fail;
}
--
2.20.1
^ permalink raw reply related [flat|nested] 23+ messages in thread
* [Qemu-devel] [PULL 11/21] nbd/client: Split out nbd_send_meta_query()
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
` (9 preceding siblings ...)
2019-01-21 22:48 ` [Qemu-devel] [PULL 10/21] nbd/client: Change signature of nbd_negotiate_simple_meta_context() Eric Blake
@ 2019-01-21 22:48 ` Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 12/21] nbd/client: Split out nbd_receive_one_meta_context() Eric Blake
` (10 subsequent siblings)
21 siblings, 0 replies; 23+ messages in thread
From: Eric Blake @ 2019-01-21 22:48 UTC (permalink / raw)
To: qemu-devel
Cc: Richard W . M . Jones, Vladimir Sementsov-Ogievskiy,
open list:Network Block Dev...
Refactor nbd_negotiate_simple_meta_context() to pull out the
code that can be reused to send a LIST request for 0 or 1 query.
No semantic change. The old comment about 'sizeof(uint32_t)'
being equivalent to '/* number of queries */' is no longer
needed, now that we are computing 'sizeof(queries)' instead.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Message-Id: <20190117193658.16413-12-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
nbd/client.c | 64 +++++++++++++++++++++++++++++++++---------------
nbd/trace-events | 2 +-
2 files changed, 45 insertions(+), 21 deletions(-)
diff --git a/nbd/client.c b/nbd/client.c
index 77993890f04..96da68ee18a 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -629,6 +629,46 @@ static QIOChannel *nbd_receive_starttls(QIOChannel *ioc,
return QIO_CHANNEL(tioc);
}
+/*
+ * nbd_send_meta_query:
+ * Send 0 or 1 set/list meta context queries.
+ * Return 0 on success, -1 with errp set for any error
+ */
+static int nbd_send_meta_query(QIOChannel *ioc, uint32_t opt,
+ const char *export, const char *query,
+ Error **errp)
+{
+ int ret;
+ uint32_t export_len = strlen(export);
+ uint32_t queries = !!query;
+ uint32_t query_len = 0;
+ uint32_t data_len;
+ char *data;
+ char *p;
+
+ data_len = sizeof(export_len) + export_len + sizeof(queries);
+ if (query) {
+ query_len = strlen(query);
+ data_len += sizeof(query_len) + query_len;
+ } else {
+ assert(opt == NBD_OPT_LIST_META_CONTEXT);
+ }
+ p = data = g_malloc(data_len);
+
+ trace_nbd_opt_meta_request(nbd_opt_lookup(opt), query ?: "(all)", export);
+ stl_be_p(p, export_len);
+ memcpy(p += sizeof(export_len), export, export_len);
+ stl_be_p(p += export_len, queries);
+ if (query) {
+ stl_be_p(p += sizeof(queries), query_len);
+ memcpy(p += sizeof(query_len), query, query_len);
+ }
+
+ ret = nbd_send_option_request(ioc, opt, data_len, data, errp);
+ g_free(data);
+ return ret;
+}
+
/* nbd_negotiate_simple_meta_context:
* Request the server to set the meta context for export @info->name
* using @info->x_dirty_bitmap with a fallback to "base:allocation",
@@ -653,26 +693,10 @@ static int nbd_negotiate_simple_meta_context(QIOChannel *ioc,
NBDOptionReply reply;
const char *context = info->x_dirty_bitmap ?: "base:allocation";
bool received = false;
- uint32_t export_len = strlen(info->name);
- uint32_t context_len = strlen(context);
- uint32_t data_len = sizeof(export_len) + export_len +
- sizeof(uint32_t) + /* number of queries */
- sizeof(context_len) + context_len;
- char *data = g_malloc(data_len);
- char *p = data;
- trace_nbd_opt_meta_request(context, info->name);
- stl_be_p(p, export_len);
- memcpy(p += sizeof(export_len), info->name, export_len);
- stl_be_p(p += export_len, 1);
- stl_be_p(p += sizeof(uint32_t), context_len);
- memcpy(p += sizeof(context_len), context, context_len);
-
- ret = nbd_send_option_request(ioc, NBD_OPT_SET_META_CONTEXT, data_len, data,
- errp);
- g_free(data);
- if (ret < 0) {
- return ret;
+ if (nbd_send_meta_query(ioc, NBD_OPT_SET_META_CONTEXT,
+ info->name, context, errp) < 0) {
+ return -1;
}
if (nbd_receive_option_reply(ioc, NBD_OPT_SET_META_CONTEXT, &reply,
@@ -689,7 +713,7 @@ static int nbd_negotiate_simple_meta_context(QIOChannel *ioc,
if (reply.type == NBD_REP_META_CONTEXT) {
char *name;
- if (reply.length != sizeof(info->context_id) + context_len) {
+ if (reply.length != sizeof(info->context_id) + strlen(context)) {
error_setg(errp, "Failed to negotiate meta context '%s', server "
"answered with unexpected length %" PRIu32, context,
reply.length);
diff --git a/nbd/trace-events b/nbd/trace-events
index c3966d2b653..59521e47a3d 100644
--- a/nbd/trace-events
+++ b/nbd/trace-events
@@ -12,7 +12,7 @@ nbd_receive_query_exports_start(const char *wantname) "Querying export list for
nbd_receive_query_exports_success(const char *wantname) "Found desired export name '%s'"
nbd_receive_starttls_new_client(void) "Setting up TLS"
nbd_receive_starttls_tls_handshake(void) "Starting TLS handshake"
-nbd_opt_meta_request(const char *context, const char *export) "Requesting to set meta context %s for export %s"
+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 *context, uint32_t id) "Received mapping of context %s to id %" PRIu32
nbd_receive_negotiate(void *tlscreds, const char *hostname) "Receiving negotiation tlscreds=%p hostname=%s"
nbd_receive_negotiate_magic(uint64_t magic) "Magic is 0x%" PRIx64
--
2.20.1
^ permalink raw reply related [flat|nested] 23+ messages in thread
* [Qemu-devel] [PULL 12/21] nbd/client: Split out nbd_receive_one_meta_context()
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
` (10 preceding siblings ...)
2019-01-21 22:48 ` [Qemu-devel] [PULL 11/21] nbd/client: Split out nbd_send_meta_query() Eric Blake
@ 2019-01-21 22:48 ` Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 13/21] nbd/client: Refactor return of nbd_receive_negotiate() Eric Blake
` (9 subsequent siblings)
21 siblings, 0 replies; 23+ messages in thread
From: Eric Blake @ 2019-01-21 22:48 UTC (permalink / raw)
To: qemu-devel; +Cc: Vladimir Sementsov-Ogievskiy, open list:Network Block Dev...
Extract portions of nbd_negotiate_simple_meta_context() to
a new function nbd_receive_one_meta_context() that copies the
pattern of nbd_receive_list() for performing the argument
validation of one reply. The error message when the server
replies with more than one context changes slightly, but
that shouldn't happen in the common case.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190117193658.16413-13-eblake@redhat.com>
---
nbd/client.c | 147 +++++++++++++++++++++++++++++------------------
nbd/trace-events | 2 +-
2 files changed, 91 insertions(+), 58 deletions(-)
diff --git a/nbd/client.c b/nbd/client.c
index 96da68ee18a..c7bb7081553 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -669,7 +669,86 @@ static int nbd_send_meta_query(QIOChannel *ioc, uint32_t opt,
return ret;
}
-/* nbd_negotiate_simple_meta_context:
+/*
+ * nbd_receive_one_meta_context:
+ * Called in a loop to receive and trace one set/list meta context reply.
+ * Pass non-NULL @name or @id to collect results back to the caller, which
+ * must eventually call g_free().
+ * return 1 if name is set and iteration must continue,
+ * 0 if iteration is complete (including if option is unsupported),
+ * -1 with errp set for any error
+ */
+static int nbd_receive_one_meta_context(QIOChannel *ioc,
+ uint32_t opt,
+ char **name,
+ uint32_t *id,
+ Error **errp)
+{
+ int ret;
+ NBDOptionReply reply;
+ char *local_name = NULL;
+ uint32_t local_id;
+
+ if (nbd_receive_option_reply(ioc, opt, &reply, errp) < 0) {
+ return -1;
+ }
+
+ ret = nbd_handle_reply_err(ioc, &reply, errp);
+ if (ret <= 0) {
+ return ret;
+ }
+
+ if (reply.type == NBD_REP_ACK) {
+ if (reply.length != 0) {
+ error_setg(errp, "Unexpected length to ACK response");
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+ return 0;
+ } else if (reply.type != NBD_REP_META_CONTEXT) {
+ error_setg(errp, "Unexpected reply type %u (%s), expected %u (%s)",
+ reply.type, nbd_rep_lookup(reply.type),
+ NBD_REP_META_CONTEXT, nbd_rep_lookup(NBD_REP_META_CONTEXT));
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+
+ if (reply.length <= sizeof(local_id) ||
+ reply.length > NBD_MAX_BUFFER_SIZE) {
+ error_setg(errp, "Failed to negotiate meta context, server "
+ "answered with unexpected length %" PRIu32,
+ reply.length);
+ nbd_send_opt_abort(ioc);
+ return -1;
+ }
+
+ if (nbd_read(ioc, &local_id, sizeof(local_id), errp) < 0) {
+ return -1;
+ }
+ local_id = be32_to_cpu(local_id);
+
+ reply.length -= sizeof(local_id);
+ local_name = g_malloc(reply.length + 1);
+ if (nbd_read(ioc, local_name, reply.length, errp) < 0) {
+ g_free(local_name);
+ return -1;
+ }
+ local_name[reply.length] = '\0';
+ trace_nbd_opt_meta_reply(nbd_opt_lookup(opt), local_name, local_id);
+
+ if (name) {
+ *name = local_name;
+ } else {
+ g_free(local_name);
+ }
+ if (id) {
+ *id = local_id;
+ }
+ return 1;
+}
+
+/*
+ * nbd_negotiate_simple_meta_context:
* Request the server to set the meta context for export @info->name
* using @info->x_dirty_bitmap with a fallback to "base:allocation",
* setting @info->context_id to the resulting id. Fail if the server
@@ -690,50 +769,21 @@ static int nbd_negotiate_simple_meta_context(QIOChannel *ioc,
* function should lose the term _simple.
*/
int ret;
- NBDOptionReply reply;
const char *context = info->x_dirty_bitmap ?: "base:allocation";
bool received = false;
+ char *name = NULL;
if (nbd_send_meta_query(ioc, NBD_OPT_SET_META_CONTEXT,
info->name, context, errp) < 0) {
return -1;
}
- if (nbd_receive_option_reply(ioc, NBD_OPT_SET_META_CONTEXT, &reply,
- errp) < 0)
- {
+ ret = nbd_receive_one_meta_context(ioc, NBD_OPT_SET_META_CONTEXT,
+ &name, &info->context_id, errp);
+ if (ret < 0) {
return -1;
}
-
- ret = nbd_handle_reply_err(ioc, &reply, errp);
- if (ret <= 0) {
- return ret;
- }
-
- if (reply.type == NBD_REP_META_CONTEXT) {
- char *name;
-
- if (reply.length != sizeof(info->context_id) + strlen(context)) {
- error_setg(errp, "Failed to negotiate meta context '%s', server "
- "answered with unexpected length %" PRIu32, context,
- reply.length);
- nbd_send_opt_abort(ioc);
- return -1;
- }
-
- if (nbd_read(ioc, &info->context_id, sizeof(info->context_id),
- errp) < 0) {
- return -1;
- }
- info->context_id = be32_to_cpu(info->context_id);
-
- reply.length -= sizeof(info->context_id);
- name = g_malloc(reply.length + 1);
- if (nbd_read(ioc, name, reply.length, errp) < 0) {
- g_free(name);
- return -1;
- }
- name[reply.length] = '\0';
+ if (ret == 1) {
if (strcmp(context, name)) {
error_setg(errp, "Failed to negotiate meta context '%s', server "
"answered with different context '%s'", context,
@@ -743,36 +793,19 @@ static int nbd_negotiate_simple_meta_context(QIOChannel *ioc,
return -1;
}
g_free(name);
-
- trace_nbd_opt_meta_reply(context, info->context_id);
received = true;
- /* receive NBD_REP_ACK */
- if (nbd_receive_option_reply(ioc, NBD_OPT_SET_META_CONTEXT, &reply,
- errp) < 0)
- {
+ ret = nbd_receive_one_meta_context(ioc, NBD_OPT_SET_META_CONTEXT,
+ NULL, NULL, errp);
+ if (ret < 0) {
return -1;
}
-
- ret = nbd_handle_reply_err(ioc, &reply, errp);
- if (ret <= 0) {
- return ret;
- }
}
-
- if (reply.type != NBD_REP_ACK) {
- error_setg(errp, "Unexpected reply type %u (%s), expected %u (%s)",
- reply.type, nbd_rep_lookup(reply.type),
- NBD_REP_ACK, nbd_rep_lookup(NBD_REP_ACK));
+ if (ret != 0) {
+ error_setg(errp, "Server answered with more than one context");
nbd_send_opt_abort(ioc);
return -1;
}
- if (reply.length) {
- error_setg(errp, "Unexpected length to ACK response");
- nbd_send_opt_abort(ioc);
- return -1;
- }
-
return received;
}
diff --git a/nbd/trace-events b/nbd/trace-events
index 59521e47a3d..b4802c1570e 100644
--- a/nbd/trace-events
+++ b/nbd/trace-events
@@ -13,7 +13,7 @@ nbd_receive_query_exports_success(const char *wantname) "Found desired export na
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 *context, uint32_t id) "Received mapping of context %s to id %" PRIu32
+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_receive_negotiate_magic(uint64_t magic) "Magic is 0x%" PRIx64
nbd_receive_negotiate_server_flags(uint32_t globalflags) "Global flags are 0x%" PRIx32
--
2.20.1
^ permalink raw reply related [flat|nested] 23+ messages in thread
* [Qemu-devel] [PULL 13/21] nbd/client: Refactor return of nbd_receive_negotiate()
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
` (11 preceding siblings ...)
2019-01-21 22:48 ` [Qemu-devel] [PULL 12/21] nbd/client: Split out nbd_receive_one_meta_context() Eric Blake
@ 2019-01-21 22:48 ` Eric Blake
2019-01-21 22:49 ` [Qemu-devel] [PULL 14/21] nbd/client: Split handshake into two functions Eric Blake
` (8 subsequent siblings)
21 siblings, 0 replies; 23+ messages in thread
From: Eric Blake @ 2019-01-21 22:48 UTC (permalink / raw)
To: qemu-devel
Cc: Richard W . M . Jones, Vladimir Sementsov-Ogievskiy,
open list:Network Block Dev...
The function could only ever return 0 or -EINVAL; make this
clearer by dropping a useless 'fail:' label.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190117193658.16413-14-eblake@redhat.com>
---
nbd/client.c | 51 +++++++++++++++++++++++----------------------------
1 file changed, 23 insertions(+), 28 deletions(-)
diff --git a/nbd/client.c b/nbd/client.c
index c7bb7081553..9028fd09397 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -814,7 +814,6 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
NBDExportInfo *info, Error **errp)
{
uint64_t magic;
- int rc;
bool zeroes = true;
bool structured_reply = info->structured_reply;
bool base_allocation = info->base_allocation;
@@ -825,31 +824,30 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
trace_nbd_receive_negotiate_name(info->name);
info->structured_reply = false;
info->base_allocation = false;
- rc = -EINVAL;
if (outioc) {
*outioc = NULL;
}
if (tlscreds && !outioc) {
error_setg(errp, "Output I/O channel required for TLS");
- goto fail;
+ return -EINVAL;
}
if (nbd_read(ioc, &magic, sizeof(magic), errp) < 0) {
error_prepend(errp, "Failed to read initial magic: ");
- goto fail;
+ return -EINVAL;
}
magic = be64_to_cpu(magic);
trace_nbd_receive_negotiate_magic(magic);
if (magic != NBD_INIT_MAGIC) {
error_setg(errp, "Bad initial magic received: 0x%" PRIx64, magic);
- goto fail;
+ return -EINVAL;
}
if (nbd_read(ioc, &magic, sizeof(magic), errp) < 0) {
error_prepend(errp, "Failed to read server magic: ");
- goto fail;
+ return -EINVAL;
}
magic = be64_to_cpu(magic);
trace_nbd_receive_negotiate_magic(magic);
@@ -861,7 +859,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
if (nbd_read(ioc, &globalflags, sizeof(globalflags), errp) < 0) {
error_prepend(errp, "Failed to read server flags: ");
- goto fail;
+ return -EINVAL;
}
globalflags = be16_to_cpu(globalflags);
trace_nbd_receive_negotiate_server_flags(globalflags);
@@ -877,18 +875,18 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
clientflags = cpu_to_be32(clientflags);
if (nbd_write(ioc, &clientflags, sizeof(clientflags), errp) < 0) {
error_prepend(errp, "Failed to send clientflags field: ");
- goto fail;
+ return -EINVAL;
}
if (tlscreds) {
if (fixedNewStyle) {
*outioc = nbd_receive_starttls(ioc, tlscreds, hostname, errp);
if (!*outioc) {
- goto fail;
+ return -EINVAL;
}
ioc = *outioc;
} else {
error_setg(errp, "Server does not support STARTTLS");
- goto fail;
+ return -EINVAL;
}
}
if (fixedNewStyle) {
@@ -899,7 +897,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
NBD_OPT_STRUCTURED_REPLY,
errp);
if (result < 0) {
- goto fail;
+ return -EINVAL;
}
info->structured_reply = result == 1;
}
@@ -907,7 +905,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
if (info->structured_reply && base_allocation) {
result = nbd_negotiate_simple_meta_context(ioc, info, errp);
if (result < 0) {
- goto fail;
+ return -EINVAL;
}
info->base_allocation = result == 1;
}
@@ -919,7 +917,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
* export, then use NBD_OPT_EXPORT_NAME. */
result = nbd_opt_go(ioc, info, errp);
if (result < 0) {
- goto fail;
+ return -EINVAL;
}
if (result > 0) {
return 0;
@@ -931,25 +929,25 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
* export name is not available.
*/
if (nbd_receive_query_exports(ioc, info->name, errp) < 0) {
- goto fail;
+ return -EINVAL;
}
}
/* write the export name request */
if (nbd_send_option_request(ioc, NBD_OPT_EXPORT_NAME, -1, info->name,
errp) < 0) {
- goto fail;
+ return -EINVAL;
}
/* Read the response */
if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) {
error_prepend(errp, "Failed to read export length: ");
- goto fail;
+ return -EINVAL;
}
info->size = be64_to_cpu(info->size);
if (nbd_read(ioc, &info->flags, sizeof(info->flags), errp) < 0) {
error_prepend(errp, "Failed to read export flags: ");
- goto fail;
+ return -EINVAL;
}
info->flags = be16_to_cpu(info->flags);
} else if (magic == NBD_CLIENT_MAGIC) {
@@ -957,43 +955,40 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
if (*info->name) {
error_setg(errp, "Server does not support non-empty export names");
- goto fail;
+ return -EINVAL;
}
if (tlscreds) {
error_setg(errp, "Server does not support STARTTLS");
- goto fail;
+ return -EINVAL;
}
if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) {
error_prepend(errp, "Failed to read export length: ");
- goto fail;
+ return -EINVAL;
}
info->size = be64_to_cpu(info->size);
if (nbd_read(ioc, &oldflags, sizeof(oldflags), errp) < 0) {
error_prepend(errp, "Failed to read export flags: ");
- goto fail;
+ return -EINVAL;
}
oldflags = be32_to_cpu(oldflags);
if (oldflags & ~0xffff) {
error_setg(errp, "Unexpected export flags %0x" PRIx32, oldflags);
- goto fail;
+ return -EINVAL;
}
info->flags = oldflags;
} else {
error_setg(errp, "Bad server magic received: 0x%" PRIx64, magic);
- goto fail;
+ return -EINVAL;
}
trace_nbd_receive_negotiate_size_flags(info->size, info->flags);
if (zeroes && nbd_drop(ioc, 124, errp) < 0) {
error_prepend(errp, "Failed to read reserved block: ");
- goto fail;
+ return -EINVAL;
}
- rc = 0;
-
-fail:
- return rc;
+ return 0;
}
#ifdef __linux__
--
2.20.1
^ permalink raw reply related [flat|nested] 23+ messages in thread
* [Qemu-devel] [PULL 14/21] nbd/client: Split handshake into two functions
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
` (12 preceding siblings ...)
2019-01-21 22:48 ` [Qemu-devel] [PULL 13/21] nbd/client: Refactor return of nbd_receive_negotiate() Eric Blake
@ 2019-01-21 22:49 ` Eric Blake
2019-01-21 22:49 ` [Qemu-devel] [PULL 15/21] nbd/client: Pull out oldstyle size determination Eric Blake
` (7 subsequent siblings)
21 siblings, 0 replies; 23+ messages in thread
From: Eric Blake @ 2019-01-21 22:49 UTC (permalink / raw)
To: qemu-devel
Cc: Richard W . M . Jones, Vladimir Sementsov-Ogievskiy,
open list:Network Block Dev...
An upcoming patch will add the ability for qemu-nbd to list
the services provided by an NBD server. Share the common
code of the TLS handshake by splitting the initial exchange
into a separate function, leaving only the export handling
in the original function. Functionally, there should be no
change in behavior in this patch, although some of the code
motion may be difficult to follow due to indentation changes
(view with 'git diff -w' for a smaller changeset).
I considered an enum for the return code coordinating state
between the two functions, but in the end just settled with
ample comments.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190117193658.16413-15-eblake@redhat.com>
---
nbd/client.c | 145 +++++++++++++++++++++++++++++++----------------
nbd/trace-events | 2 +-
2 files changed, 96 insertions(+), 51 deletions(-)
diff --git a/nbd/client.c b/nbd/client.c
index 9028fd09397..77cc12356f2 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;
+
+ 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;
+ }
- /* 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);
+ 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 b4802c1570e..663d11687ab 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'"
--
2.20.1
^ permalink raw reply related [flat|nested] 23+ messages in thread
* [Qemu-devel] [PULL 15/21] nbd/client: Pull out oldstyle size determination
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
` (13 preceding siblings ...)
2019-01-21 22:49 ` [Qemu-devel] [PULL 14/21] nbd/client: Split handshake into two functions Eric Blake
@ 2019-01-21 22:49 ` Eric Blake
2019-01-21 22:49 ` [Qemu-devel] [PULL 16/21] nbd/client: Refactor nbd_opt_go() to support NBD_OPT_INFO Eric Blake
` (6 subsequent siblings)
21 siblings, 0 replies; 23+ messages in thread
From: Eric Blake @ 2019-01-21 22:49 UTC (permalink / raw)
To: qemu-devel
Cc: Richard W . M . Jones, Vladimir Sementsov-Ogievskiy,
open list:Network Block Dev...
Another refactoring creating nbd_negotiate_finish_oldstyle()
for further reuse during 'qemu-nbd --list'.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Message-Id: <20190117193658.16413-16-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
nbd/client.c | 49 ++++++++++++++++++++++++++++++++-----------------
1 file changed, 32 insertions(+), 17 deletions(-)
diff --git a/nbd/client.c b/nbd/client.c
index 77cc12356f2..6829c684fec 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -814,7 +814,7 @@ static int nbd_negotiate_simple_meta_context(QIOChannel *ioc,
* 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
+ * 0: server is oldstyle, must call nbd_negotiate_finish_oldstyle
* 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
@@ -920,6 +920,36 @@ static int nbd_start_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
}
}
+/*
+ * nbd_negotiate_finish_oldstyle:
+ * Populate @info with the size and export flags from an oldstyle server,
+ * but does not consume 124 bytes of reserved zero padding.
+ * Returns 0 on success, -1 with @errp set on failure
+ */
+static int nbd_negotiate_finish_oldstyle(QIOChannel *ioc, NBDExportInfo *info,
+ Error **errp)
+{
+ uint32_t oldflags;
+
+ if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) {
+ error_prepend(errp, "Failed to read export length: ");
+ return -EINVAL;
+ }
+ info->size = be64_to_cpu(info->size);
+
+ if (nbd_read(ioc, &oldflags, sizeof(oldflags), errp) < 0) {
+ error_prepend(errp, "Failed to read export flags: ");
+ return -EINVAL;
+ }
+ oldflags = be32_to_cpu(oldflags);
+ if (oldflags & ~0xffff) {
+ error_setg(errp, "Unexpected export flags %0x" PRIx32, oldflags);
+ return -EINVAL;
+ }
+ info->flags = oldflags;
+ return 0;
+}
+
/*
* nbd_receive_negotiate:
* Connect to server, complete negotiation, and move into transmission phase.
@@ -933,7 +963,6 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
int result;
bool zeroes;
bool base_allocation = info->base_allocation;
- uint32_t oldflags;
assert(info->name);
trace_nbd_receive_negotiate_name(info->name);
@@ -1006,23 +1035,9 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
error_setg(errp, "Server does not support non-empty export names");
return -EINVAL;
}
-
- if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) {
- error_prepend(errp, "Failed to read export length: ");
+ if (nbd_negotiate_finish_oldstyle(ioc, info, errp) < 0) {
return -EINVAL;
}
- info->size = be64_to_cpu(info->size);
-
- if (nbd_read(ioc, &oldflags, sizeof(oldflags), errp) < 0) {
- error_prepend(errp, "Failed to read export flags: ");
- return -EINVAL;
- }
- oldflags = be32_to_cpu(oldflags);
- if (oldflags & ~0xffff) {
- error_setg(errp, "Unexpected export flags %0x" PRIx32, oldflags);
- return -EINVAL;
- }
- info->flags = oldflags;
break;
default:
return result;
--
2.20.1
^ permalink raw reply related [flat|nested] 23+ messages in thread
* [Qemu-devel] [PULL 16/21] nbd/client: Refactor nbd_opt_go() to support NBD_OPT_INFO
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
` (14 preceding siblings ...)
2019-01-21 22:49 ` [Qemu-devel] [PULL 15/21] nbd/client: Pull out oldstyle size determination Eric Blake
@ 2019-01-21 22:49 ` Eric Blake
2019-01-21 22:49 ` [Qemu-devel] [PULL 17/21] nbd/client: Add nbd_receive_export_list() Eric Blake
` (5 subsequent siblings)
21 siblings, 0 replies; 23+ messages in thread
From: Eric Blake @ 2019-01-21 22:49 UTC (permalink / raw)
To: qemu-devel; +Cc: Vladimir Sementsov-Ogievskiy, open list:Network Block Dev...
Rename the function to nbd_opt_info_or_go() with an added parameter
and slight changes to comments and trace messages, in order to
reuse the function for NBD_OPT_INFO.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190117193658.16413-17-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
nbd/client.c | 36 ++++++++++++++++++++++--------------
nbd/trace-events | 8 ++++----
2 files changed, 26 insertions(+), 18 deletions(-)
diff --git a/nbd/client.c b/nbd/client.c
index 6829c684fec..fa1657a1cb3 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -330,11 +330,16 @@ static int nbd_receive_list(QIOChannel *ioc, char **name, char **description,
}
-/* Returns -1 if NBD_OPT_GO proves the export @info->name cannot be
- * used, 0 if NBD_OPT_GO is unsupported (fall back to NBD_OPT_LIST and
+/*
+ * nbd_opt_info_or_go:
+ * Send option for NBD_OPT_INFO or NBD_OPT_GO and parse the reply.
+ * Returns -1 if the option proves the export @info->name cannot be
+ * used, 0 if the option is unsupported (fall back to NBD_OPT_LIST and
* NBD_OPT_EXPORT_NAME in that case), and > 0 if the export is good to
- * go (with the rest of @info populated). */
-static int nbd_opt_go(QIOChannel *ioc, NBDExportInfo *info, Error **errp)
+ * go (with the rest of @info populated).
+ */
+static int nbd_opt_info_or_go(QIOChannel *ioc, uint32_t opt,
+ NBDExportInfo *info, Error **errp)
{
NBDOptionReply reply;
uint32_t len = strlen(info->name);
@@ -347,7 +352,8 @@ static int nbd_opt_go(QIOChannel *ioc, NBDExportInfo *info, Error **errp)
* flags still 0 is a witness of a broken server. */
info->flags = 0;
- trace_nbd_opt_go_start(info->name);
+ assert(opt == NBD_OPT_GO || opt == NBD_OPT_INFO);
+ trace_nbd_opt_info_go_start(nbd_opt_lookup(opt), info->name);
buf = g_malloc(4 + len + 2 + 2 * info->request_sizes + 1);
stl_be_p(buf, len);
memcpy(buf + 4, info->name, len);
@@ -356,7 +362,7 @@ static int nbd_opt_go(QIOChannel *ioc, NBDExportInfo *info, Error **errp)
if (info->request_sizes) {
stw_be_p(buf + 4 + len + 2, NBD_INFO_BLOCK_SIZE);
}
- error = nbd_send_option_request(ioc, NBD_OPT_GO,
+ error = nbd_send_option_request(ioc, opt,
4 + len + 2 + 2 * info->request_sizes,
buf, errp);
g_free(buf);
@@ -365,7 +371,7 @@ static int nbd_opt_go(QIOChannel *ioc, NBDExportInfo *info, Error **errp)
}
while (1) {
- if (nbd_receive_option_reply(ioc, NBD_OPT_GO, &reply, errp) < 0) {
+ if (nbd_receive_option_reply(ioc, opt, &reply, errp) < 0) {
return -1;
}
error = nbd_handle_reply_err(ioc, &reply, errp);
@@ -375,8 +381,10 @@ static int nbd_opt_go(QIOChannel *ioc, NBDExportInfo *info, Error **errp)
len = reply.length;
if (reply.type == NBD_REP_ACK) {
- /* Server is done sending info and moved into transmission
- phase, but make sure it sent flags */
+ /*
+ * Server is done sending info, and moved into transmission
+ * phase for NBD_OPT_GO, but make sure it sent flags
+ */
if (len) {
error_setg(errp, "server sent invalid NBD_REP_ACK");
return -1;
@@ -385,7 +393,7 @@ static int nbd_opt_go(QIOChannel *ioc, NBDExportInfo *info, Error **errp)
error_setg(errp, "broken server omitted NBD_INFO_EXPORT");
return -1;
}
- trace_nbd_opt_go_success();
+ trace_nbd_opt_info_go_success(nbd_opt_lookup(opt));
return 1;
}
if (reply.type != NBD_REP_INFO) {
@@ -479,12 +487,12 @@ static int nbd_opt_go(QIOChannel *ioc, NBDExportInfo *info, Error **errp)
nbd_send_opt_abort(ioc);
return -1;
}
- trace_nbd_opt_go_info_block_size(info->min_block, info->opt_block,
- info->max_block);
+ trace_nbd_opt_info_block_size(info->min_block, info->opt_block,
+ info->max_block);
break;
default:
- trace_nbd_opt_go_info_unknown(type, nbd_info_lookup(type));
+ trace_nbd_opt_info_unknown(type, nbd_info_lookup(type));
if (nbd_drop(ioc, len, errp) < 0) {
error_prepend(errp, "Failed to read info payload: ");
nbd_send_opt_abort(ioc);
@@ -993,7 +1001,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
* 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);
+ result = nbd_opt_info_or_go(ioc, NBD_OPT_GO, info, errp);
if (result < 0) {
return -EINVAL;
}
diff --git a/nbd/trace-events b/nbd/trace-events
index 663d11687ab..7f10ebd4e0b 100644
--- a/nbd/trace-events
+++ b/nbd/trace-events
@@ -4,10 +4,10 @@ nbd_receive_option_reply(uint32_t option, const char *optname, uint32_t type, co
nbd_server_error_msg(uint32_t err, const char *type, const char *msg) "server reported error 0x%" PRIx32 " (%s) with additional message: %s"
nbd_reply_err_unsup(uint32_t option, const char *name) "server doesn't understand request %" PRIu32 " (%s), attempting fallback"
nbd_receive_list(const char *name, const char *desc) "export list includes '%s', description '%s'"
-nbd_opt_go_start(const char *name) "Attempting NBD_OPT_GO for export '%s'"
-nbd_opt_go_success(void) "Export is good to go"
-nbd_opt_go_info_unknown(int info, const char *name) "Ignoring unknown info %d (%s)"
-nbd_opt_go_info_block_size(uint32_t minimum, uint32_t preferred, uint32_t maximum) "Block sizes are 0x%" PRIx32 ", 0x%" PRIx32 ", 0x%" PRIx32
+nbd_opt_info_go_start(const char *opt, const char *name) "Attempting %s for export '%s'"
+nbd_opt_info_go_success(const char *opt) "Export is ready after %s request"
+nbd_opt_info_unknown(int info, const char *name) "Ignoring unknown info %d (%s)"
+nbd_opt_info_block_size(uint32_t minimum, uint32_t preferred, uint32_t maximum) "Block sizes are 0x%" PRIx32 ", 0x%" PRIx32 ", 0x%" PRIx32
nbd_receive_query_exports_start(const char *wantname) "Querying export list for '%s'"
nbd_receive_query_exports_success(const char *wantname) "Found desired export name '%s'"
nbd_receive_starttls_new_client(void) "Setting up TLS"
--
2.20.1
^ permalink raw reply related [flat|nested] 23+ messages in thread
* [Qemu-devel] [PULL 17/21] nbd/client: Add nbd_receive_export_list()
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
` (15 preceding siblings ...)
2019-01-21 22:49 ` [Qemu-devel] [PULL 16/21] nbd/client: Refactor nbd_opt_go() to support NBD_OPT_INFO Eric Blake
@ 2019-01-21 22:49 ` Eric Blake
2019-01-21 22:49 ` [Qemu-devel] [PULL 18/21] nbd/client: Add meta contexts to nbd_receive_export_list() Eric Blake
` (4 subsequent siblings)
21 siblings, 0 replies; 23+ messages in thread
From: Eric Blake @ 2019-01-21 22:49 UTC (permalink / raw)
To: qemu-devel
Cc: Richard W . M . Jones, Vladimir Sementsov-Ogievskiy, Kevin Wolf,
Max Reitz, open list:Network Block Dev...
We want to be able to detect whether a given qemu NBD server is
exposing the right export(s) and dirty bitmaps, at least for
regression testing. We could use 'nbd-client -l' from the upstream
NBD project to list exports, but it's annoying to rely on
out-of-tree binaries; furthermore, nbd-client doesn't necessarily
know about all of the qemu NBD extensions. Thus, we plan on adding
a new mode to qemu-nbd that merely sniffs all possible information
from the server during handshake phase, then disconnects and dumps
the information.
This patch adds the low-level client code for grabbing the list
of exports. It benefits from the recent refactoring patches, in
order to share as much code as possible when it comes to doing
validation of server replies. The resulting information is stored
in an array of NBDExportInfo which has been expanded to any
description string, along with a convenience function for freeing
the list.
Note: a malicious server could exhaust memory of a client by feeding
an unending loop of exports; perhaps we should place a limit on how
many we are willing to receive. But note that a server could
reasonably be serving an export for every file in a large directory,
where an arbitrary limit in the client means we can't list anything
from such a server; the same happens if we just run until the client
fails to malloc() and thus dies by an abort(), where the limit is
no longer arbitrary but determined by available memory. Since the
client is already planning on being short-lived, it's hard to call
this a denial of service attack that would starve off other uses,
so it does not appear to be a security issue.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Message-Id: <20190117193658.16413-18-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
include/block/nbd.h | 15 ++++-
nbd/client.c | 132 +++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 143 insertions(+), 4 deletions(-)
diff --git a/include/block/nbd.h b/include/block/nbd.h
index be19aac2fc7..19332b46715 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2016-2017 Red Hat, Inc.
+ * Copyright (C) 2016-2019 Red Hat, Inc.
* Copyright (C) 2005 Anthony Liguori <anthony@codemonkey.ws>
*
* Network Block Device
@@ -262,6 +262,9 @@ struct NBDExportInfo {
/* Set by client before nbd_receive_negotiate() */
bool request_sizes;
char *x_dirty_bitmap;
+
+ /* Set by client before nbd_receive_negotiate(), or by server results
+ * during nbd_receive_export_list() */
char *name; /* must be non-NULL */
/* In-out fields, set by client before nbd_receive_negotiate() and
@@ -269,7 +272,8 @@ struct NBDExportInfo {
bool structured_reply;
bool base_allocation; /* base:allocation context for NBD_CMD_BLOCK_STATUS */
- /* Set by server results during nbd_receive_negotiate() */
+ /* Set by server results during nbd_receive_negotiate() and
+ * nbd_receive_export_list() */
uint64_t size;
uint16_t flags;
uint32_t min_block;
@@ -277,12 +281,19 @@ struct NBDExportInfo {
uint32_t max_block;
uint32_t context_id;
+
+ /* Set by server results during nbd_receive_export_list() */
+ char *description;
};
typedef struct NBDExportInfo NBDExportInfo;
int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
const char *hostname, QIOChannel **outioc,
NBDExportInfo *info, Error **errp);
+void nbd_free_export_list(NBDExportInfo *info, int count);
+int nbd_receive_export_list(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
+ const char *hostname, NBDExportInfo **info,
+ Error **errp);
int nbd_init(int fd, QIOChannelSocket *sioc, NBDExportInfo *info,
Error **errp);
int nbd_send_request(QIOChannel *ioc, NBDRequest *request);
diff --git a/nbd/client.c b/nbd/client.c
index fa1657a1cb3..8a32169970d 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -836,7 +836,9 @@ static int nbd_start_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
trace_nbd_start_negotiate(tlscreds, hostname ? hostname : "<null>");
- *zeroes = true;
+ if (zeroes) {
+ *zeroes = true;
+ }
if (outioc) {
*outioc = NULL;
}
@@ -880,7 +882,9 @@ static int nbd_start_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
clientflags |= NBD_FLAG_C_FIXED_NEWSTYLE;
}
if (globalflags & NBD_FLAG_NO_ZEROES) {
- *zeroes = false;
+ if (zeroes) {
+ *zeroes = false;
+ }
clientflags |= NBD_FLAG_C_NO_ZEROES;
}
/* client requested flags */
@@ -1059,6 +1063,130 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
return 0;
}
+/* Clean up result of nbd_receive_export_list */
+void nbd_free_export_list(NBDExportInfo *info, int count)
+{
+ int i;
+
+ if (!info) {
+ return;
+ }
+
+ for (i = 0; i < count; i++) {
+ g_free(info[i].name);
+ g_free(info[i].description);
+ }
+ g_free(info);
+}
+
+/*
+ * nbd_receive_export_list:
+ * Query details about a server's exports, then disconnect without
+ * going into transmission phase. Return a count of the exports listed
+ * in @info by the server, or -1 on error. Caller must free @info using
+ * nbd_free_export_list().
+ */
+int nbd_receive_export_list(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
+ const char *hostname, NBDExportInfo **info,
+ Error **errp)
+{
+ int result;
+ int count = 0;
+ int i;
+ int rc;
+ int ret = -1;
+ NBDExportInfo *array = NULL;
+ QIOChannel *sioc = NULL;
+
+ *info = NULL;
+ result = nbd_start_negotiate(ioc, tlscreds, hostname, &sioc, true, NULL,
+ errp);
+ if (tlscreds && sioc) {
+ ioc = sioc;
+ }
+
+ switch (result) {
+ case 2:
+ case 3:
+ /* 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. */
+ if (nbd_send_option_request(ioc, NBD_OPT_LIST, 0, NULL, errp) < 0) {
+ goto out;
+ }
+ while (1) {
+ char *name;
+ char *desc;
+
+ rc = nbd_receive_list(ioc, &name, &desc, errp);
+ if (rc < 0) {
+ goto out;
+ } else if (rc == 0) {
+ break;
+ }
+ array = g_renew(NBDExportInfo, array, ++count);
+ memset(&array[count - 1], 0, sizeof(*array));
+ array[count - 1].name = name;
+ array[count - 1].description = desc;
+ array[count - 1].structured_reply = result == 3;
+ }
+
+ for (i = 0; i < count; i++) {
+ array[i].request_sizes = true;
+ rc = nbd_opt_info_or_go(ioc, NBD_OPT_INFO, &array[i], errp);
+ if (rc < 0) {
+ goto out;
+ } else if (rc == 0) {
+ /*
+ * Pointless to try rest of loop. If OPT_INFO doesn't work,
+ * it's unlikely that meta contexts work either
+ */
+ break;
+ }
+
+ /* TODO: Grab meta contexts */
+ }
+
+ /* Send NBD_OPT_ABORT as a courtesy before hanging up */
+ nbd_send_opt_abort(ioc);
+ break;
+ case 1: /* newstyle, but limited to EXPORT_NAME */
+ error_setg(errp, "Server does not support export lists");
+ /* We can't even send NBD_OPT_ABORT, so merely hang up */
+ goto out;
+ case 0: /* oldstyle, parse length and flags */
+ array = g_new0(NBDExportInfo, 1);
+ array->name = g_strdup("");
+ count = 1;
+
+ if (nbd_negotiate_finish_oldstyle(ioc, array, errp) < 0) {
+ goto out;
+ }
+
+ /* Send NBD_CMD_DISC as a courtesy to the server, but ignore all
+ * errors now that we have the information we wanted. */
+ if (nbd_drop(ioc, 124, NULL) == 0) {
+ NBDRequest request = { .type = NBD_CMD_DISC };
+
+ nbd_send_request(ioc, &request);
+ }
+ break;
+ default:
+ goto out;
+ }
+
+ *info = array;
+ array = NULL;
+ ret = count;
+
+ out:
+ qio_channel_shutdown(ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
+ qio_channel_close(ioc, NULL);
+ object_unref(OBJECT(sioc));
+ nbd_free_export_list(array, count);
+ return ret;
+}
+
#ifdef __linux__
int nbd_init(int fd, QIOChannelSocket *sioc, NBDExportInfo *info,
Error **errp)
--
2.20.1
^ permalink raw reply related [flat|nested] 23+ messages in thread
* [Qemu-devel] [PULL 18/21] nbd/client: Add meta contexts to nbd_receive_export_list()
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
` (16 preceding siblings ...)
2019-01-21 22:49 ` [Qemu-devel] [PULL 17/21] nbd/client: Add nbd_receive_export_list() Eric Blake
@ 2019-01-21 22:49 ` Eric Blake
2019-01-21 22:49 ` [Qemu-devel] [PULL 19/21] qemu-nbd: Add --list option Eric Blake
` (3 subsequent siblings)
21 siblings, 0 replies; 23+ messages in thread
From: Eric Blake @ 2019-01-21 22:49 UTC (permalink / raw)
To: qemu-devel
Cc: Richard W . M . Jones, Vladimir Sementsov-Ogievskiy, Kevin Wolf,
Max Reitz, open list:Network Block Dev...
We want to be able to detect whether a given qemu NBD server is
exposing the right export(s) and dirty bitmaps, at least for
regression testing. We could use 'nbd-client -l' from the upstream
NBD project to list exports, but it's annoying to rely on
out-of-tree binaries; furthermore, nbd-client doesn't necessarily
know about all of the qemu NBD extensions. Thus, we plan on adding
a new mode to qemu-nbd that merely sniffs all possible information
from the server during handshake phase, then disconnects and dumps
the information.
This patch continues the work of the previous patch, by adding the
ability to track the list of available meta contexts into
NBDExportInfo. It benefits from the recent refactoring patches
with a new nbd_list_meta_contexts() that reuses much of the same
framework as setting a meta context.
Note: a malicious server could exhaust memory of a client by feeding
an unending loop of contexts; perhaps we could place a limit on how
many we are willing to receive. But this is no different from our
earlier analysis on a server sending an unending list of exports,
and the death of a client due to memory exhaustion when the client
was going to exit soon anyways is not really a denial of service
attack.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190117193658.16413-19-eblake@redhat.com>
---
include/block/nbd.h | 2 ++
nbd/client.c | 41 +++++++++++++++++++++++++++++++++++++++--
2 files changed, 41 insertions(+), 2 deletions(-)
diff --git a/include/block/nbd.h b/include/block/nbd.h
index 19332b46715..4faf394e346 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -284,6 +284,8 @@ struct NBDExportInfo {
/* Set by server results during nbd_receive_export_list() */
char *description;
+ int n_contexts;
+ char **contexts;
};
typedef struct NBDExportInfo NBDExportInfo;
diff --git a/nbd/client.c b/nbd/client.c
index 8a32169970d..798b82f205a 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -817,6 +817,36 @@ static int nbd_negotiate_simple_meta_context(QIOChannel *ioc,
return received;
}
+/*
+ * nbd_list_meta_contexts:
+ * Request the server to list all meta contexts for export @info->name.
+ * return 0 if list is complete (even if empty),
+ * -1 with errp set for any error
+ */
+static int nbd_list_meta_contexts(QIOChannel *ioc,
+ NBDExportInfo *info,
+ Error **errp)
+{
+ int ret;
+
+ if (nbd_send_meta_query(ioc, NBD_OPT_LIST_META_CONTEXT,
+ info->name, NULL, errp) < 0) {
+ return -1;
+ }
+
+ while (1) {
+ char *context;
+
+ ret = nbd_receive_one_meta_context(ioc, NBD_OPT_LIST_META_CONTEXT,
+ &context, NULL, errp);
+ if (ret <= 0) {
+ return ret;
+ }
+ info->contexts = g_renew(char *, info->contexts, ++info->n_contexts);
+ info->contexts[info->n_contexts - 1] = context;
+ }
+}
+
/*
* nbd_start_negotiate:
* Start the handshake to the server. After a positive return, the server
@@ -1066,7 +1096,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
/* Clean up result of nbd_receive_export_list */
void nbd_free_export_list(NBDExportInfo *info, int count)
{
- int i;
+ int i, j;
if (!info) {
return;
@@ -1075,6 +1105,10 @@ void nbd_free_export_list(NBDExportInfo *info, int count)
for (i = 0; i < count; i++) {
g_free(info[i].name);
g_free(info[i].description);
+ for (j = 0; j < info[i].n_contexts; j++) {
+ g_free(info[i].contexts[j]);
+ }
+ g_free(info[i].contexts);
}
g_free(info);
}
@@ -1144,7 +1178,10 @@ int nbd_receive_export_list(QIOChannel *ioc, QCryptoTLSCreds *tlscreds,
break;
}
- /* TODO: Grab meta contexts */
+ if (result == 3 &&
+ nbd_list_meta_contexts(ioc, &array[i], errp) < 0) {
+ goto out;
+ }
}
/* Send NBD_OPT_ABORT as a courtesy before hanging up */
--
2.20.1
^ permalink raw reply related [flat|nested] 23+ messages in thread
* [Qemu-devel] [PULL 19/21] qemu-nbd: Add --list option
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
` (17 preceding siblings ...)
2019-01-21 22:49 ` [Qemu-devel] [PULL 18/21] nbd/client: Add meta contexts to nbd_receive_export_list() Eric Blake
@ 2019-01-21 22:49 ` Eric Blake
2019-01-21 22:49 ` [Qemu-devel] [PULL 20/21] nbd/client: Work around 3.0 bug for listing meta contexts Eric Blake
` (2 subsequent siblings)
21 siblings, 0 replies; 23+ messages in thread
From: Eric Blake @ 2019-01-21 22:49 UTC (permalink / raw)
To: qemu-devel
Cc: Richard W . M . Jones, Vladimir Sementsov-Ogievskiy,
open list:Network Block Dev...
We want to be able to detect whether a given qemu NBD server is
exposing the right export(s) and dirty bitmaps, at least for
regression testing. We could use 'nbd-client -l' from the upstream
NBD project to list exports, but it's annoying to rely on
out-of-tree binaries; furthermore, nbd-client doesn't necessarily
know about all of the qemu NBD extensions. Thus, it is time to add
a new mode to qemu-nbd that merely sniffs all possible information
from the server during handshake phase, then disconnects and dumps
the information.
This patch actually implements --list/-L, while reusing other
options such as --tls-creds for now designating how to connect
as the client (rather than their non-list usage of how to operate
as the server).
I debated about adding this functionality to something akin to
'qemu-img info' - but that tool does not readily lend itself
to connecting to an arbitrary NBD server without also tying to
a specific export (I may, however, still add ImageInfoSpecificNBD
for reporting the bitmaps available when connecting to a single
export). And, while it may feel a bit odd that normally
qemu-nbd is a server but 'qemu-nbd -L' is a client, we are not
really making the qemu-nbd binary that much larger, because
'qemu-nbd -c' has to operate as both server and client
simultaneously across two threads when feeding the kernel module
for /dev/nbdN access.
Sample output:
$ qemu-nbd -L
exports available: 1
export: ''
size: 65536
flags: 0x4ed ( flush fua trim zeroes df cache )
min block: 512
opt block: 4096
max block: 33554432
available meta contexts: 1
base:allocation
Note that the output only lists sizes if the server sent
NBD_FLAG_HAS_FLAGS, because a newstyle server does not give
the size otherwise. It has the side effect that for really
old servers that did not send any flags, the size is not
output even though it was available. However, I'm not too
concerned about that - oldstyle servers are (rightfully)
getting less common to encounter (qemu 3.0 was the last
version where we even serve it), and most existing servers
that still even offer oldstyle negotiation (such as nbdkit)
still send flags (since that was added to the NBD protocol
in 2007 to permit read-only connections).
Not done here, but maybe worth future experiments: capture
the meat of NBDExportInfo into a QAPI struct, and use the
generated QAPI pretty-printers instead of hand-rolling our
output loop. It would also permit us to add a JSON output
mode for machine parsing.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Message-Id: <20190117193658.16413-20-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
qemu-nbd.texi | 29 ++++++++--
qemu-nbd.c | 155 +++++++++++++++++++++++++++++++++++++++++++++-----
2 files changed, 167 insertions(+), 17 deletions(-)
diff --git a/qemu-nbd.texi b/qemu-nbd.texi
index f218291bf30..386bece4680 100644
--- a/qemu-nbd.texi
+++ b/qemu-nbd.texi
@@ -2,6 +2,8 @@
@c man begin SYNOPSIS
@command{qemu-nbd} [OPTION]... @var{filename}
+@command{qemu-nbd} @option{-L} [OPTION]...
+
@command{qemu-nbd} @option{-d} @var{dev}
@c man end
@end example
@@ -14,6 +16,8 @@ Other uses:
@itemize
@item
Bind a /dev/nbdX block device to a QEMU server (on Linux).
+@item
+As a client to query exports of a remote NBD server.
@end itemize
@c man end
@@ -31,13 +35,15 @@ See the @code{qemu(1)} manual page for full details of the properties
supported. The common object types that it makes sense to define are the
@code{secret} object, which is used to supply passwords and/or encryption
keys, and the @code{tls-creds} object, which is used to supply TLS
-credentials for the qemu-nbd server.
+credentials for the qemu-nbd server or client.
@item -p, --port=@var{port}
-The TCP port to listen on (default @samp{10809}).
+The TCP port to listen on as a server, or connect to as a client
+(default @samp{10809}).
@item -o, --offset=@var{offset}
The offset into the image.
@item -b, --bind=@var{iface}
-The interface to bind to (default @samp{0.0.0.0}).
+The interface to bind to as a server, or connect to as a client
+(default @samp{0.0.0.0}).
@item -k, --socket=@var{path}
Use a unix socket with path @var{path}.
@item --image-opts
@@ -97,10 +103,16 @@ Set the NBD volume export name (default of a zero-length string).
@item -D, --description=@var{description}
Set the NBD volume export description, as a human-readable
string.
+@item -L, --list
+Connect as a client and list all details about the exports exposed by
+a remote NBD server. This enables list mode, and is incompatible
+with options that change behavior related to a specific export (such as
+@option{--export-name}, @option{--offset}, ...).
@item --tls-creds=ID
Enable mandatory TLS encryption for the server by setting the ID
of the TLS credentials object previously created with the --object
-option.
+option; or provide the credentials needed for connecting as a client
+in list mode.
@item --fork
Fork off the server process and exit the parent once the server is running.
@item -v, --verbose
@@ -162,6 +174,15 @@ qemu-nbd -c /dev/nbd0 -f qcow2 file.qcow2
qemu-nbd -d /dev/nbd0
@end example
+Query a remote server to see details about what export(s) it is
+serving on port 10809, and authenticating via PSK:
+
+@example
+qemu-nbd \
+ --object tls-creds-psk,id=tls0,dir=/tmp/keys,username=eblake,endpoint=client \
+ --tls-creds tls0 -L -b remote.example.com
+@end example
+
@c man end
@ignore
diff --git a/qemu-nbd.c b/qemu-nbd.c
index 3c538700eae..1f7b2a03f5d 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -76,7 +76,8 @@ static void usage(const char *name)
{
(printf) (
"Usage: %s [OPTIONS] FILE\n"
-"QEMU Disk Network Block Device Server\n"
+" or: %s -L [OPTIONS]\n"
+"QEMU Disk Network Block Device Utility\n"
"\n"
" -h, --help display this help and exit\n"
" -V, --version output version information and exit\n"
@@ -98,6 +99,7 @@ static void usage(const char *name)
" -B, --bitmap=NAME expose a persistent dirty bitmap\n"
"\n"
"General purpose options:\n"
+" -L, --list list exports available from another NBD server\n"
" --object type,id=ID,... define an object such as 'secret' for providing\n"
" passwords and/or encryption keys\n"
" --tls-creds=ID use id of an earlier --object to provide TLS\n"
@@ -131,7 +133,7 @@ static void usage(const char *name)
" --image-opts treat FILE as a full set of image options\n"
"\n"
QEMU_HELP_BOTTOM "\n"
- , name, NBD_DEFAULT_PORT, "DEVICE");
+ , name, name, NBD_DEFAULT_PORT, "DEVICE");
}
static void version(const char *name)
@@ -243,6 +245,91 @@ static void termsig_handler(int signum)
}
+static int qemu_nbd_client_list(SocketAddress *saddr, QCryptoTLSCreds *tls,
+ const char *hostname)
+{
+ int ret = EXIT_FAILURE;
+ int rc;
+ Error *err = NULL;
+ QIOChannelSocket *sioc;
+ NBDExportInfo *list;
+ int i, j;
+
+ sioc = qio_channel_socket_new();
+ if (qio_channel_socket_connect_sync(sioc, saddr, &err) < 0) {
+ error_report_err(err);
+ return EXIT_FAILURE;
+ }
+ rc = nbd_receive_export_list(QIO_CHANNEL(sioc), tls, hostname, &list,
+ &err);
+ if (rc < 0) {
+ if (err) {
+ error_report_err(err);
+ }
+ goto out;
+ }
+ printf("exports available: %d\n", rc);
+ for (i = 0; i < rc; i++) {
+ printf(" export: '%s'\n", list[i].name);
+ if (list[i].description && *list[i].description) {
+ printf(" description: %s\n", list[i].description);
+ }
+ if (list[i].flags & NBD_FLAG_HAS_FLAGS) {
+ printf(" size: %" PRIu64 "\n", list[i].size);
+ printf(" flags: 0x%x (", list[i].flags);
+ if (list[i].flags & NBD_FLAG_READ_ONLY) {
+ printf(" readonly");
+ }
+ if (list[i].flags & NBD_FLAG_SEND_FLUSH) {
+ printf(" flush");
+ }
+ if (list[i].flags & NBD_FLAG_SEND_FUA) {
+ printf(" fua");
+ }
+ if (list[i].flags & NBD_FLAG_ROTATIONAL) {
+ printf(" rotational");
+ }
+ if (list[i].flags & NBD_FLAG_SEND_TRIM) {
+ printf(" trim");
+ }
+ if (list[i].flags & NBD_FLAG_SEND_WRITE_ZEROES) {
+ printf(" zeroes");
+ }
+ if (list[i].flags & NBD_FLAG_SEND_DF) {
+ printf(" df");
+ }
+ if (list[i].flags & NBD_FLAG_CAN_MULTI_CONN) {
+ printf(" multi");
+ }
+ if (list[i].flags & NBD_FLAG_SEND_RESIZE) {
+ printf(" resize");
+ }
+ if (list[i].flags & NBD_FLAG_SEND_CACHE) {
+ printf(" cache");
+ }
+ printf(" )\n");
+ }
+ if (list[i].min_block) {
+ printf(" min block: %u\n", list[i].min_block);
+ printf(" opt block: %u\n", list[i].opt_block);
+ printf(" max block: %u\n", list[i].max_block);
+ }
+ if (list[i].n_contexts) {
+ printf(" available meta contexts: %d\n", list[i].n_contexts);
+ for (j = 0; j < list[i].n_contexts; j++) {
+ printf(" %s\n", list[i].contexts[j]);
+ }
+ }
+ }
+ nbd_free_export_list(list, rc);
+
+ ret = EXIT_SUCCESS;
+ out:
+ object_unref(OBJECT(sioc));
+ return ret;
+}
+
+
#if HAVE_NBD_DEVICE
static void *show_parts(void *arg)
{
@@ -425,7 +512,8 @@ static QemuOptsList qemu_object_opts = {
-static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
+static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, bool list,
+ Error **errp)
{
Object *obj;
QCryptoTLSCreds *creds;
@@ -445,10 +533,18 @@ static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp)
return NULL;
}
- if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
- error_setg(errp,
- "Expecting TLS credentials with a server endpoint");
- return NULL;
+ if (list) {
+ if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT) {
+ error_setg(errp,
+ "Expecting TLS credentials with a client endpoint");
+ return NULL;
+ }
+ } else {
+ if (creds->endpoint != QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
+ error_setg(errp,
+ "Expecting TLS credentials with a server endpoint");
+ return NULL;
+ }
}
object_ref(obj);
return creds;
@@ -471,7 +567,8 @@ static void setup_address_and_port(const char **address, const char **port)
static const char *socket_activation_validate_opts(const char *device,
const char *sockpath,
const char *address,
- const char *port)
+ const char *port,
+ bool list)
{
if (device != NULL) {
return "NBD device can't be set when using socket activation";
@@ -489,6 +586,10 @@ static const char *socket_activation_validate_opts(const char *device,
return "TCP port number can't be set when using socket activation";
}
+ if (list) {
+ return "List mode is incompatible with socket activation";
+ }
+
return NULL;
}
@@ -512,7 +613,7 @@ int main(int argc, char **argv)
int64_t fd_size;
QemuOpts *sn_opts = NULL;
const char *sn_id_or_name = NULL;
- const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:D:B:";
+ const char *sopt = "hVb:o:p:rsnP:c:dvk:e:f:tl:x:T:D:B:L";
struct option lopt[] = {
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, 'V' },
@@ -525,6 +626,7 @@ int main(int argc, char **argv)
{ "bitmap", required_argument, NULL, 'B' },
{ "connect", required_argument, NULL, 'c' },
{ "disconnect", no_argument, NULL, 'd' },
+ { "list", no_argument, NULL, 'L' },
{ "snapshot", no_argument, NULL, 's' },
{ "load-snapshot", required_argument, NULL, 'l' },
{ "nocache", no_argument, NULL, 'n' },
@@ -559,7 +661,7 @@ int main(int argc, char **argv)
Error *local_err = NULL;
BlockdevDetectZeroesOptions detect_zeroes = BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF;
QDict *options = NULL;
- const char *export_name = ""; /* Default export name */
+ const char *export_name = NULL; /* defaults to "" later for server mode */
const char *export_description = NULL;
const char *bitmap = NULL;
const char *tlscredsid = NULL;
@@ -567,6 +669,7 @@ int main(int argc, char **argv)
bool writethrough = true;
char *trace_file = NULL;
bool fork_process = false;
+ bool list = false;
int old_stderr = -1;
unsigned socket_activation;
@@ -760,13 +863,33 @@ int main(int argc, char **argv)
case QEMU_NBD_OPT_FORK:
fork_process = true;
break;
+ case 'L':
+ list = true;
+ break;
}
}
- if ((argc - optind) != 1) {
+ if (list) {
+ if (argc != optind) {
+ error_report("List mode is incompatible with a file name");
+ exit(EXIT_FAILURE);
+ }
+ if (export_name || export_description || dev_offset || partition ||
+ device || disconnect || fmt || sn_id_or_name || bitmap ||
+ seen_aio || seen_discard || seen_cache) {
+ error_report("List mode is incompatible with per-device settings");
+ exit(EXIT_FAILURE);
+ }
+ if (fork_process) {
+ error_report("List mode is incompatible with forking");
+ exit(EXIT_FAILURE);
+ }
+ } else if ((argc - optind) != 1) {
error_report("Invalid number of arguments");
error_printf("Try `%s --help' for more information.\n", argv[0]);
exit(EXIT_FAILURE);
+ } else if (!export_name) {
+ export_name = "";
}
qemu_opts_foreach(&qemu_object_opts,
@@ -785,7 +908,8 @@ int main(int argc, char **argv)
} else {
/* Using socket activation - check user didn't use -p etc. */
const char *err_msg = socket_activation_validate_opts(device, sockpath,
- bindto, port);
+ bindto, port,
+ list);
if (err_msg != NULL) {
error_report("%s", err_msg);
exit(EXIT_FAILURE);
@@ -808,7 +932,7 @@ int main(int argc, char **argv)
error_report("TLS is not supported with a host device");
exit(EXIT_FAILURE);
}
- tlscreds = nbd_get_tls_creds(tlscredsid, &local_err);
+ tlscreds = nbd_get_tls_creds(tlscredsid, list, &local_err);
if (local_err) {
error_report("Failed to get TLS creds %s",
error_get_pretty(local_err));
@@ -816,6 +940,11 @@ int main(int argc, char **argv)
}
}
+ if (list) {
+ saddr = nbd_build_socket_address(sockpath, bindto, port);
+ return qemu_nbd_client_list(saddr, tlscreds, bindto);
+ }
+
#if !HAVE_NBD_DEVICE
if (disconnect || device) {
error_report("Kernel /dev/nbdN support not available");
--
2.20.1
^ permalink raw reply related [flat|nested] 23+ messages in thread
* [Qemu-devel] [PULL 20/21] nbd/client: Work around 3.0 bug for listing meta contexts
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
` (18 preceding siblings ...)
2019-01-21 22:49 ` [Qemu-devel] [PULL 19/21] qemu-nbd: Add --list option Eric Blake
@ 2019-01-21 22:49 ` Eric Blake
2019-01-21 22:49 ` [Qemu-devel] [PULL 21/21] iotests: Enhance 223, 233 to cover 'qemu-nbd --list' Eric Blake
2019-01-22 19:23 ` [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Peter Maydell
21 siblings, 0 replies; 23+ messages in thread
From: Eric Blake @ 2019-01-21 22:49 UTC (permalink / raw)
To: qemu-devel; +Cc: Vladimir Sementsov-Ogievskiy, open list:Network Block Dev...
Commit 3d068aff forgot to advertise available qemu: contexts
when the client requests a list with 0 queries. Furthermore,
3.0 shipped with a qemu-img hack of x-dirty-bitmap (commit
216ee365) that _silently_ acts as though the entire image is
clean if a requested bitmap is not present. Both bugs have
been recently fixed, so that a modern qemu server gives full
context output right away, and the client refuses a
connection if a requested x-dirty-bitmap was not found.
Still, it is likely that there will be users that have to
work with a mix of old and new qemu versions, depending on
which features get backported where, at which point being
able to rely on 'qemu-img --list' output to know for sure
whether a given NBD export has the desired dirty bitmap is
much nicer than blindly connecting and risking that the
entire image may appear clean. We can make our --list code
smart enough to work around buggy servers by tracking
whether we've seen any qemu: replies in the original 0-query
list; if not, repeat with a single query on "qemu:" (which
may still have no replies, but then we know for sure we
didn't trip up on the server bug).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190117193658.16413-21-eblake@redhat.com>
---
nbd/client.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/nbd/client.c b/nbd/client.c
index 798b82f205a..8a083c2f42c 100644
--- a/nbd/client.c
+++ b/nbd/client.c
@@ -21,6 +21,7 @@
#include "qapi/error.h"
#include "trace.h"
#include "nbd-internal.h"
+#include "qemu/cutils.h"
/* Definitions for opaque data types */
@@ -828,6 +829,8 @@ static int nbd_list_meta_contexts(QIOChannel *ioc,
Error **errp)
{
int ret;
+ int seen_any = false;
+ int seen_qemu = false;
if (nbd_send_meta_query(ioc, NBD_OPT_LIST_META_CONTEXT,
info->name, NULL, errp) < 0) {
@@ -839,9 +842,25 @@ static int nbd_list_meta_contexts(QIOChannel *ioc,
ret = nbd_receive_one_meta_context(ioc, NBD_OPT_LIST_META_CONTEXT,
&context, NULL, errp);
+ if (ret == 0 && seen_any && !seen_qemu) {
+ /*
+ * Work around qemu 3.0 bug: the server forgot to send
+ * "qemu:" replies to 0 queries. If we saw at least one
+ * reply (probably base:allocation), but none of them were
+ * qemu:, then run a more specific query to make sure.
+ */
+ seen_qemu = true;
+ if (nbd_send_meta_query(ioc, NBD_OPT_LIST_META_CONTEXT,
+ info->name, "qemu:", errp) < 0) {
+ return -1;
+ }
+ continue;
+ }
if (ret <= 0) {
return ret;
}
+ seen_any = true;
+ seen_qemu |= strstart(context, "qemu:", NULL);
info->contexts = g_renew(char *, info->contexts, ++info->n_contexts);
info->contexts[info->n_contexts - 1] = context;
}
--
2.20.1
^ permalink raw reply related [flat|nested] 23+ messages in thread
* [Qemu-devel] [PULL 21/21] iotests: Enhance 223, 233 to cover 'qemu-nbd --list'
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
` (19 preceding siblings ...)
2019-01-21 22:49 ` [Qemu-devel] [PULL 20/21] nbd/client: Work around 3.0 bug for listing meta contexts Eric Blake
@ 2019-01-21 22:49 ` Eric Blake
2019-01-22 19:23 ` [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Peter Maydell
21 siblings, 0 replies; 23+ messages in thread
From: Eric Blake @ 2019-01-21 22:49 UTC (permalink / raw)
To: qemu-devel
Cc: Richard W . M . Jones, Vladimir Sementsov-Ogievskiy, Kevin Wolf,
Max Reitz, open list:Block layer core
Any good new feature deserves some regression testing :)
Coverage includes:
- 223: what happens when there are 0 or more than 1 export,
proof that we can see multiple contexts including qemu:dirty-bitmap
- 233: proof that we can list over TLS, and that mix-and-match of
plain/TLS listings will behave sanely
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Tested-by: Richard W.M. Jones <rjones@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190117193658.16413-22-eblake@redhat.com>
---
tests/qemu-iotests/223 | 2 ++
tests/qemu-iotests/223.out | 20 ++++++++++++++++++++
tests/qemu-iotests/233 | 19 +++++++++++++------
tests/qemu-iotests/233.out | 15 +++++++++++++++
4 files changed, 50 insertions(+), 6 deletions(-)
diff --git a/tests/qemu-iotests/223 b/tests/qemu-iotests/223
index 773892dbe60..f120a016460 100755
--- a/tests/qemu-iotests/223
+++ b/tests/qemu-iotests/223
@@ -127,6 +127,7 @@ _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-start",
_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-start",
"arguments":{"addr":{"type":"unix",
"data":{"path":"'"$TEST_DIR/nbd"1'"}}}}' "error" # Attempt second server
+$QEMU_NBD_PROG -L -k "$TEST_DIR/nbd"
_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
"arguments":{"device":"n", "bitmap":"b"}}' "return"
_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
@@ -142,6 +143,7 @@ _send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
_send_qemu_cmd $QEMU_HANDLE '{"execute":"nbd-server-add",
"arguments":{"device":"n", "name":"n2", "writable":true,
"bitmap":"b2"}}' "return"
+$QEMU_NBD_PROG -L -k "$TEST_DIR/nbd"
echo
echo "=== Contrast normal status to large granularity dirty-bitmap ==="
diff --git a/tests/qemu-iotests/223.out b/tests/qemu-iotests/223.out
index 0de5240a75e..6476b77ba20 100644
--- a/tests/qemu-iotests/223.out
+++ b/tests/qemu-iotests/223.out
@@ -30,12 +30,32 @@ wrote 2097152/2097152 bytes at offset 2097152
{"error": {"class": "GenericError", "desc": "NBD server not running"}}
{"return": {}}
{"error": {"class": "GenericError", "desc": "NBD server already running"}}
+exports available: 0
{"return": {}}
{"error": {"class": "GenericError", "desc": "Cannot find device=nosuch nor node_name=nosuch"}}
{"error": {"class": "GenericError", "desc": "NBD server already has export named 'n'"}}
{"error": {"class": "GenericError", "desc": "Enabled bitmap 'b2' incompatible with readonly export"}}
{"error": {"class": "GenericError", "desc": "Bitmap 'b3' is not found"}}
{"return": {}}
+exports available: 2
+ export: 'n'
+ size: 4194304
+ flags: 0x4ef ( readonly flush fua trim zeroes df cache )
+ min block: 512
+ opt block: 4096
+ max block: 33554432
+ available meta contexts: 2
+ base:allocation
+ qemu:dirty-bitmap:b
+ export: 'n2'
+ size: 4194304
+ flags: 0x4ed ( flush fua trim zeroes df cache )
+ min block: 512
+ opt block: 4096
+ max block: 33554432
+ available meta contexts: 2
+ base:allocation
+ qemu:dirty-bitmap:b2
=== Contrast normal status to large granularity dirty-bitmap ===
diff --git a/tests/qemu-iotests/233 b/tests/qemu-iotests/233
index ab15c777370..fc345a1a46e 100755
--- a/tests/qemu-iotests/233
+++ b/tests/qemu-iotests/233
@@ -69,10 +69,12 @@ echo
echo "== check TLS client to plain server fails =="
nbd_server_start_tcp_socket -f $IMGFMT "$TEST_IMG" 2> "$TEST_DIR/server.log"
-$QEMU_IMG info --image-opts \
- --object tls-creds-x509,dir=${tls_dir}/client1,endpoint=client,id=tls0 \
+obj=tls-creds-x509,dir=${tls_dir}/client1,endpoint=client,id=tls0
+$QEMU_IMG info --image-opts --object $obj \
driver=nbd,host=$nbd_tcp_addr,port=$nbd_tcp_port,tls-creds=tls0 \
2>&1 | sed "s/$nbd_tcp_port/PORT/g"
+$QEMU_NBD_PROG -L -b $nbd_tcp_addr -p $nbd_tcp_port --object $obj \
+ --tls-creds=tls0
nbd_server_stop
@@ -85,20 +87,25 @@ nbd_server_start_tcp_socket \
-f $IMGFMT "$TEST_IMG" 2>> "$TEST_DIR/server.log"
$QEMU_IMG info nbd://localhost:$nbd_tcp_port 2>&1 | sed "s/$nbd_tcp_port/PORT/g"
+$QEMU_NBD_PROG -L -b $nbd_tcp_addr -p $nbd_tcp_port
echo
echo "== check TLS works =="
-$QEMU_IMG info --image-opts \
- --object tls-creds-x509,dir=${tls_dir}/client1,endpoint=client,id=tls0 \
+obj=tls-creds-x509,dir=${tls_dir}/client1,endpoint=client,id=tls0
+$QEMU_IMG info --image-opts --object $obj \
driver=nbd,host=$nbd_tcp_addr,port=$nbd_tcp_port,tls-creds=tls0 \
2>&1 | sed "s/$nbd_tcp_port/PORT/g"
+$QEMU_NBD_PROG -L -b $nbd_tcp_addr -p $nbd_tcp_port --object $obj \
+ --tls-creds=tls0
echo
echo "== check TLS with different CA fails =="
-$QEMU_IMG info --image-opts \
- --object tls-creds-x509,dir=${tls_dir}/client2,endpoint=client,id=tls0 \
+obj=tls-creds-x509,dir=${tls_dir}/client2,endpoint=client,id=tls0
+$QEMU_IMG info --image-opts --object $obj \
driver=nbd,host=$nbd_tcp_addr,port=$nbd_tcp_port,tls-creds=tls0 \
2>&1 | sed "s/$nbd_tcp_port/PORT/g"
+$QEMU_NBD_PROG -L -b $nbd_tcp_addr -p $nbd_tcp_port --object $obj \
+ --tls-creds=tls0
echo
echo "== perform I/O over TLS =="
diff --git a/tests/qemu-iotests/233.out b/tests/qemu-iotests/233.out
index 2199d8a8b32..6d45f3b2304 100644
--- a/tests/qemu-iotests/233.out
+++ b/tests/qemu-iotests/233.out
@@ -15,19 +15,33 @@ wrote 1048576/1048576 bytes at offset 1048576
== check TLS client to plain server fails ==
qemu-img: Could not open 'driver=nbd,host=127.0.0.1,port=PORT,tls-creds=tls0': Denied by server for option 5 (starttls)
server reported: TLS not configured
+qemu-nbd: Denied by server for option 5 (starttls)
+server reported: TLS not configured
== check plain client to TLS server fails ==
qemu-img: Could not open 'nbd://localhost:PORT': TLS negotiation required before option 8 (structured reply)
server reported: Option 0x8 not permitted before TLS
+qemu-nbd: TLS negotiation required before option 8 (structured reply)
+server reported: Option 0x8 not permitted before TLS
== check TLS works ==
image: nbd://127.0.0.1:PORT
file format: nbd
virtual size: 64M (67108864 bytes)
disk size: unavailable
+exports available: 1
+ export: ''
+ size: 67108864
+ flags: 0x4ed ( flush fua trim zeroes df cache )
+ min block: 512
+ opt block: 4096
+ max block: 33554432
+ available meta contexts: 1
+ base:allocation
== 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
+qemu-nbd: The certificate hasn't got a known issuer
== perform I/O over TLS ==
read 1048576/1048576 bytes at offset 1048576
@@ -39,4 +53,5 @@ read 1048576/1048576 bytes at offset 1048576
== final server log ==
qemu-nbd: option negotiation failed: Verify failed: No certificate was found.
+qemu-nbd: option negotiation failed: Verify failed: No certificate was found.
*** done
--
2.20.1
^ permalink raw reply related [flat|nested] 23+ messages in thread
* Re: [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
` (20 preceding siblings ...)
2019-01-21 22:49 ` [Qemu-devel] [PULL 21/21] iotests: Enhance 223, 233 to cover 'qemu-nbd --list' Eric Blake
@ 2019-01-22 19:23 ` Peter Maydell
21 siblings, 0 replies; 23+ messages in thread
From: Peter Maydell @ 2019-01-22 19:23 UTC (permalink / raw)
To: Eric Blake; +Cc: QEMU Developers
On Mon, 21 Jan 2019 at 22:51, Eric Blake <eblake@redhat.com> wrote:
>
> The following changes since commit 166609e6070fab3424510ac7292ecb585f8b80fb:
>
> Merge remote-tracking branch 'remotes/amarkovic/tags/mips-queue-january-17-2019-v2' into staging (2019-01-21 17:53:28 +0000)
>
> are available in the Git repository at:
>
> https://repo.or.cz/qemu/ericb.git tags/pull-nbd-2019-01-21
>
> for you to fetch changes up to ddd09448fd833d646952c769ae9ce3d39bee989f:
>
> iotests: Enhance 223, 233 to cover 'qemu-nbd --list' (2019-01-21 15:49:52 -0600)
>
> ----------------------------------------------------------------
> nbd patches for 2019-01-21
>
> Add 'qemu-nbd --list' for probing a remote NBD server's advertisements.
>
> - Eric Blake: 0/21 nbd: add qemu-nbd --list
>
Applied, thanks.
Please update the changelog at https://wiki.qemu.org/ChangeLog/4.0
for any user-visible changes.
-- PMM
^ permalink raw reply [flat|nested] 23+ messages in thread
end of thread, other threads:[~2019-01-22 19:33 UTC | newest]
Thread overview: 23+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-01-21 22:48 [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 01/21] iotests: Make 233 output more reliable Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 02/21] maint: Allow for EXAMPLES in texi2pod Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 03/21] qemu-nbd: Enhance man page Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 04/21] qemu-nbd: Sanity check partition bounds Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 05/21] nbd/server: Hoist length check to qmp_nbd_server_add Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 06/21] nbd/server: Favor [u]int64_t over off_t Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 07/21] qemu-nbd: Avoid strtol open-coding Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 08/21] nbd/client: Refactor nbd_receive_list() Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 09/21] nbd/client: Move export name into NBDExportInfo Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 10/21] nbd/client: Change signature of nbd_negotiate_simple_meta_context() Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 11/21] nbd/client: Split out nbd_send_meta_query() Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 12/21] nbd/client: Split out nbd_receive_one_meta_context() Eric Blake
2019-01-21 22:48 ` [Qemu-devel] [PULL 13/21] nbd/client: Refactor return of nbd_receive_negotiate() Eric Blake
2019-01-21 22:49 ` [Qemu-devel] [PULL 14/21] nbd/client: Split handshake into two functions Eric Blake
2019-01-21 22:49 ` [Qemu-devel] [PULL 15/21] nbd/client: Pull out oldstyle size determination Eric Blake
2019-01-21 22:49 ` [Qemu-devel] [PULL 16/21] nbd/client: Refactor nbd_opt_go() to support NBD_OPT_INFO Eric Blake
2019-01-21 22:49 ` [Qemu-devel] [PULL 17/21] nbd/client: Add nbd_receive_export_list() Eric Blake
2019-01-21 22:49 ` [Qemu-devel] [PULL 18/21] nbd/client: Add meta contexts to nbd_receive_export_list() Eric Blake
2019-01-21 22:49 ` [Qemu-devel] [PULL 19/21] qemu-nbd: Add --list option Eric Blake
2019-01-21 22:49 ` [Qemu-devel] [PULL 20/21] nbd/client: Work around 3.0 bug for listing meta contexts Eric Blake
2019-01-21 22:49 ` [Qemu-devel] [PULL 21/21] iotests: Enhance 223, 233 to cover 'qemu-nbd --list' Eric Blake
2019-01-22 19:23 ` [Qemu-devel] [PULL 00/21] NBD patches through 2019-01-21 Peter Maydell
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