nbd/server: Add --selinux-label option
Under SELinux, Unix domain sockets have two labels. One is on the
disk and can be set with commands such as chcon(1). There is a
different label stored in memory (called the process label). This can
only be set by the process creating the socket. When using SELinux +
SVirt and wanting qemu to be able to connect to a qemu-nbd instance,
you must set both labels correctly first.
For qemu-nbd the options to set the second label are awkward. You can
create the socket in a wrapper program and then exec into qemu-nbd.
Or you could try something with LD_PRELOAD.
This commit adds the ability to set the label straightforwardly on the
command line, via the new --selinux-label flag. (The name of the flag
is the same as the equivalent nbdkit option.)
A worked example showing how to use the new option can be found in
this bug: https://bugzilla.redhat.com/show_bug.cgi?id=1984938
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1984938
Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
[eblake: rebase to configure changes, reject --selinux-label if it is
not compiled in or not used on a Unix socket]
Note that we may relax some of these restrictions at a later date,
such as making it possible to label a TCP socket, although it may be
smarter to do so as a generic QMP action rather than more one-off
command lines in qemu-nbd.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20211115202944.615966-1-eblake@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
[eblake: adjust meson output as suggested by thuth]
Signed-off-by: Eric Blake <eblake@redhat.com>
diff --git a/meson.build b/meson.build
index 2ece4fe..084806a 100644
--- a/meson.build
+++ b/meson.build
@@ -1201,6 +1201,11 @@
has_gettid = cc.has_function('gettid')
+# libselinux
+selinux = dependency('libselinux',
+ required: get_option('selinux'),
+ method: 'pkg-config', kwargs: static_kwargs)
+
# Malloc tests
malloc = []
@@ -1479,6 +1484,7 @@
config_host_data.set('CONFIG_SPICE', spice.found())
config_host_data.set('CONFIG_X11', x11.found())
config_host_data.set('CONFIG_CFI', get_option('cfi'))
+config_host_data.set('CONFIG_SELINUX', selinux.found())
config_host_data.set('QEMU_VERSION', '"@0@"'.format(meson.project_version()))
config_host_data.set('QEMU_VERSION_MAJOR', meson.project_version().split('.')[0])
config_host_data.set('QEMU_VERSION_MINOR', meson.project_version().split('.')[1])
@@ -3054,7 +3060,8 @@
qemu_io = executable('qemu-io', files('qemu-io.c'),
dependencies: [block, qemuutil], install: true)
qemu_nbd = executable('qemu-nbd', files('qemu-nbd.c'),
- dependencies: [blockdev, qemuutil, gnutls], install: true)
+ dependencies: [blockdev, qemuutil, gnutls, selinux],
+ install: true)
subdir('storage-daemon')
subdir('contrib/rdmacm-mux')
@@ -3430,6 +3437,7 @@
summary_info += {'libudev': libudev}
# Dummy dependency, keep .found()
summary_info += {'FUSE lseek': fuse_lseek.found()}
+summary_info += {'selinux': selinux}
summary(summary_info, bool_yn: true, section: 'Dependencies')
if not supported_cpus.contains(cpu)
