On Tue, Apr 25, 2023 at 10:40:45AM -0500, Jonathon Jongsma wrote:
On 4/25/23 9:43 AM, Jonathon Jongsma wrote:
On 4/25/23 8:11 AM, Erik Skultety wrote:
On Mon, Apr 24, 2023 at 03:50:48PM -0500, Jonathon Jongsma wrote:
When running libvirt from the build directory with the 'run' script, it will run as unconfined_t. This can result in unexpected behavior when selinux is enforcing due to the fact that the selinux policies are written assuming that libvirt is running with the system_u:system_r:virtd_t context. This patch adds a new --selinux option to the run script. When this option is specified, it will launch the specified binary using the 'runcon' utility to set its selinux context to the one mentioned above. Since this requires root privileges, setting the selinux context is not the default behavior and must be enabled with the command line switch.
A fiddled with writing custom selinux transition rules to achieve the same thing a couple years back, but never finished it. No wonder, this is a much cleaner approach. I will only comment on the Python side of things, leaving the overall approach and idea commenting to someone else.
Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com> --- run.in | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 50 insertions(+), 6 deletions(-)
diff --git a/run.in b/run.in index c6d3411082..4aa458b791 100644 --- a/run.in +++ b/run.in @@ -40,6 +40,7 @@ # # ---------------------------------------------------------------------- +import argparse import os import os.path import random @@ -59,15 +60,20 @@ def prepend(env, varname, extradir): here = "@abs_builddir@" -if len(sys.argv) < 2: - print("syntax: %s BINARY [ARGS...]" % sys.argv[0], file=sys.stderr)
Since you decided to use argparse (yes please), we can drop ^this if we properly set the arguments with argparse, it'll even generate the help for us. This way it looks only like a partial solution. Argparse has great documentation so you can just take one of the examples they list.
Yeah, I probably should have commented on why I used this 'partial' approach. I tried a few different ways, including adding a positional argument to argparse that would capture the target executable and its arguments like so:
argsparse.add_argument("args", nargs="+")
and then parsing with parser.parse_args() rather than parse_known_args(). But that prevented me from passing arguments to the target binary without inserting a '--' in to indicate that the run script should stop parsing:
Fails: # ./_build/run --selinux ./_build/src/libvirtd --verbose usage: run [--selinux] args [args ...] run: error: unrecognized arguments: --verbose
Works: # ./_build/run --selinux -- ./_build/src/libvirtd --verbose 2023-04-25 14:26:32.175+0000: 1530463: info : libvirt version: 9.3.0 ...
That seemed annoying to me.
Maybe we could keep using parse_known_args() with the 'args' argument defined above, but I have a vague recollection that this caused some other undesirable behavior so I switched back to the version I submitted. I'll try to refresh my memory.
So here's one case that becomes more annoying when using the above setup (the new 'args' catchall argument combined with parse_known_args()):
./run gdb -- libvirtd --verbose gdb: unrecognized option '--verbose'
the ./run script eats the '--' that should go to gdb, so gdb tries to interpret the --verbose option rather than passing it on to libvirtd.
I see. Without trying it/playing with it myself, I don't have a better proposal at the moment, let me have a look at this tomorrow, I'll take your patch and see if anything I'm familiar with in argparse would work, if not or if you can figure out a better way in the meantime, I'll retract my comments to this patch, how about that? Regards, Erik