run_term() uses tmux set-option -g to globally set the default shell.
Unfortunately this hits a chicken-and-egg problem that's common with many
of tmux's session options. If there isn't already a tmux server running,
we can't connect to set the option. If we attempt this after starting our
session (and therefore the server), then the session will already be
started with the previous default shell.
In any case it's not a good idea to set tmux global options, since that
might interfere with whatever else the user is doing in tmux. So, instead
set the default-shell option locally to the session after starting it. To
make sure we get the right shell for our initial script, explicitly invoke
/bin/sh to interpret it.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The semantics of tmux's update-environment option are a bit confusing.
It says it means the given variables are copied into the session
environment from the source environment, but it's not entirely clear
what the "source" environment means.
From my experimentation it appeast to be the environment from which
the tmux *server* is launched, not the one issuing the 'new-session'
command. That makes it pretty much useles, certainly in our case where
we have no way of knowing if the user has pre-existing tmux sessions.
Instead use the new-session -e option to explicitly pass in the variables
we want to propagate.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The DEBUG option for tests/run enables debugging options to passt/pasta,
however that doesn't help with debugging the test scripts themselves, which
are fairly fragile.
Extend the DEBUG option so it also prints information on each command in
the test scripts to make it easier to work out where things are falling
over.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Pass to seccomp.sh a list of additional syscalls valgrind needs as
EXTRA_SYSCALLS in a new 'valgrind' make target, and add corresponding
support in seccomp.sh itself.
In test setup functions, start passt with valgrind, but not for
performance tests.
Add tests checking that valgrind exits without errors after all the
other tests in the group are done.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
--debug can be a bit too noisy, especially as single packets or
socket messages are logged: implement a new option, --trace,
implying --debug, that enables all debug messages.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
For demos, cool-retro-term(1) looked fancier, but several threads of
that and ffmpeg(1) are just messing up with performance testing.
The CI videos started getting really big as well, and they were
difficult to read.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
...showing setup steps, some peculiarities as --net option, and a
general side-to-side comparison with slirp4netns(1), including
"quick" TCP and UDP throughput and latency benchmarks.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
To reach (at least) a conceptually equivalent security level as
implemented by --enable-sandbox in slirp4netns, we need to create a
new mount namespace and pivot_root() into a new (empty) mountpoint, so
that passt and pasta can't access any filesystem resource after
initialisation.
While at it, also detach IPC, PID (only for passt, to prevent
vulnerabilities based on the knowledge of a target PID), and UTS
namespaces.
With this approach, if we apply the seccomp filters right after the
configuration step, the number of allowed syscalls grows further. To
prevent this, defer the application of seccomp policies after the
initialisation phase, before the main loop, that's where we expect bad
things to happen, potentially. This way, we get back to 22 allowed
syscalls for passt and 34 for pasta, on x86_64.
While at it, move #syscalls notes to specific code paths wherever it
conceptually makes sense.
We have to open all the file handles we'll ever need before
sandboxing:
- the packet capture file can only be opened once, drop instance
numbers from the default path and use the (pre-sandbox) PID instead
- /proc/net/tcp{,v6} and /proc/net/udp{,v6}, for automatic detection
of bound ports in pasta mode, are now opened only once, before
sandboxing, and their handles are stored in the execution context
- the UNIX domain socket for passt is also bound only once, before
sandboxing: to reject clients after the first one, instead of
closing the listening socket, keep it open, accept and immediately
discard new connection if we already have a valid one
Clarify the (unchanged) behaviour for --netns-only in the man page.
To actually make passt and pasta processes run in a separate PID
namespace, we need to unshare(CLONE_NEWPID) before forking to
background (if configured to do so). Introduce a small daemon()
implementation, __daemon(), that additionally saves the PID file
before forking. While running in foreground, the process itself can't
move to a new PID namespace (a process can't change the notion of its
own PID): mention that in the man page.
For some reason, fork() in a detached PID namespace causes SIGTERM
and SIGQUIT to be ignored, even if the handler is still reported as
SIG_DFL: add a signal handler that just exits.
We can now drop most of the pasta_child_handler() implementation,
that took care of terminating all processes running in the same
namespace, if pasta started a shell: the shell itself is now the
init process in that namespace, and all children will terminate
once the init process exits.
Issuing 'echo $$' in a detached PID namespace won't return the
actual namespace PID as seen from the init namespace: adapt
demo and test setup scripts to reflect that.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
For distribution tests, we'll repeat some tests frequently. Add a
'def' directive that starts a block, ended by 'endef', whose
execution can then be triggered by simply giving its name as a
directive itself.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
We might have highlighting and slightly different prompts across
different distributions, allow a more reasonable set of prompt
strings to be accepted as prompts.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
With recent improvements, we're not CPU-bound at all while testing
UDP performance. Give the VM more memory and CPUs, forward two
additional ports, start up to four threads in parallel, and give
single iperf3 threads higher bandwidth targets.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
