mirror of
https://github.com/qemu/qemu.git
synced 2024-11-30 15:23:34 +08:00
e6b636779b
Currently the qemu-nbd program will auto-detect the format of any disk it is given. This behaviour is known to be insecure. For example, if qemu-nbd initially exposes a 'raw' file to an unprivileged app, and that app runs 'qemu-img create -f qcow2 -o backing_file=/etc/shadow /dev/nbd0' then the next time the app is started, the qemu-nbd will now detect it as a 'qcow2' file and expose /etc/shadow to the unprivileged app. The only way to avoid this is to explicitly tell qemu-nbd what disk format to use on the command line, completely disabling auto-detection. This patch adds a '-f' / '--format' arg for this purpose, mirroring what is already available via qemu-img and qemu commands. qemu-nbd --format raw -p 9000 evil.img will now always use raw, regardless of what format 'evil.img' looks like it contains Signed-off-by: Daniel P. Berrange <berrange@redhat.com> [Use errx, not err. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
78 lines
2.1 KiB
Plaintext
78 lines
2.1 KiB
Plaintext
@example
|
|
@c man begin SYNOPSIS
|
|
usage: qemu-nbd [OPTION]... @var{filename}
|
|
@c man end
|
|
@end example
|
|
|
|
@c man begin DESCRIPTION
|
|
|
|
Export QEMU disk image using NBD protocol.
|
|
|
|
@c man end
|
|
|
|
@c man begin OPTIONS
|
|
@table @option
|
|
@item @var{filename}
|
|
is a disk image filename
|
|
@item -p, --port=@var{port}
|
|
port to listen on (default @samp{1024})
|
|
@item -o, --offset=@var{offset}
|
|
offset into the image
|
|
@item -b, --bind=@var{iface}
|
|
interface to bind to (default @samp{0.0.0.0})
|
|
@item -k, --socket=@var{path}
|
|
Use a unix socket with path @var{path}
|
|
@item -r, --read-only
|
|
export read-only
|
|
@item -P, --partition=@var{num}
|
|
only expose partition @var{num}
|
|
@item -s, --snapshot
|
|
use snapshot file
|
|
@item -n, --nocache
|
|
@itemx --cache=@var{cache}
|
|
set cache mode to be used with the file. See the documentation of
|
|
the emulator's @code{-drive cache=...} option for allowed values.
|
|
@item --aio=@var{aio}
|
|
choose asynchronous I/O mode between @samp{threads} (the default)
|
|
and @samp{native} (Linux only).
|
|
@item --discard=@var{discard}
|
|
toggles whether @dfn{discard} (also known as @dfn{trim} or @dfn{unmap})
|
|
requests are ignored or passed to the filesystem. The default is no
|
|
(@samp{--discard=ignore}).
|
|
@item -c, --connect=@var{dev}
|
|
connect @var{filename} to NBD device @var{dev}
|
|
@item -d, --disconnect
|
|
disconnect the specified device
|
|
@item -e, --shared=@var{num}
|
|
device can be shared by @var{num} clients (default @samp{1})
|
|
@item -f, --format=@var{fmt}
|
|
force block driver for format @var{fmt} instead of auto-detecting
|
|
@item -t, --persistent
|
|
don't exit on the last connection
|
|
@item -v, --verbose
|
|
display extra debugging information
|
|
@item -h, --help
|
|
display this help and exit
|
|
@item -V, --version
|
|
output version information and exit
|
|
@end table
|
|
|
|
@c man end
|
|
|
|
@ignore
|
|
|
|
@setfilename qemu-nbd
|
|
@settitle QEMU Disk Network Block Device Server
|
|
|
|
@c man begin AUTHOR
|
|
Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>.
|
|
This is free software; see the source for copying conditions. There is NO
|
|
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
|
|
@c man end
|
|
|
|
@c man begin SEEALSO
|
|
qemu-img(1)
|
|
@c man end
|
|
|
|
@end ignore
|