Commit graph

794 commits

Author SHA1 Message Date
David Gibson
b23adf7132 test: Store pcap files in $LOGDIR instead of /tmp
The capture files are more or less a different form of log output from the
tests, so place them in $LOGDIR.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 11:12:41 +02:00
David Gibson
07aa24499e test: Move pause temporary file to state directory
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 11:12:41 +02:00
David Gibson
1c36c8d3f8 test: Use paths in __STATEDIR__ instead of 'temp' and 'tempdir' directives
Instead of using the 'temp' and 'tempdir' DSL directives to create
temporary files, use fixed paths relative to __STATEDIR__.  This has two
advantages:
  1) The files are automatically cleaned up if the tests fail (and even if
     that doesn't work they're easier to clean up manuall)
  2) When debugging tests it's easier to figure out which of the temporary
     files are relevant to whatever's going wrong

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 11:12:41 +02:00
David Gibson
c71a5e8528 test: Don't redundantly regenerate small test file in pasta/tcp
In what looks like a copy/paste error, pasta/tcp generates its small test
file twice.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 11:12:41 +02:00
David Gibson
54c5addeaa test: Move context temporary files to state dir
Currently the context command dispatch subsystem creates a bunch of
temporary files in $LOGDIR, which is messy.  Store them in $STATEDIR which
is for precisely this purpose.  The logs from each context still go into
$LOGDIR.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 11:12:41 +02:00
David Gibson
e4ecb6d795 test: Move passt_test_log_pipe to state directory
We use this fifo to send messages to the information pane.  Put it in the
state directory so it doesn't need its own cleanup.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 11:12:41 +02:00
David Gibson
8cb7d5b461 test: Create common state directories for temporary files
The test scripts create a bunch of temporary files to keep track of
internal state.  Some are made in /tmp with individual mktemp calls, some
go in the passt source directory, and some go in $LOGDIR.  This can
sometimes make it messy to clean up after failed test runs.

Start cleaning this up by creating a single "state" directory ($STATEBASE)
in /tmp for all the state or temporary files used by a single test run.
Clean it up automatically in cleanup() - except when DEBUG==1, because
those files can be useful for debugging test script failures.

We create subdirectories under $STATEBASE for each setup function, exposed
as $STATESETUP.  We also create subdirectories for each test script and
expose those to the scripts as __STATEDIR__.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 11:12:41 +02:00
David Gibson
1e4a15398f test: Actually run cleanup function
We install a cleanup() function with 'trap' in order to clean up temporary
files we generate during the tests.  However, we deinstall it after
run_term, which means it won't run in most of the cases where it would be
useful.  Even if "run from_term" exits with an error, that error will be
hidden from the run_term wrapper because it's within a tmux session, so we
will return from run_term normally, uninstall the trap and never clean up.

In fact there's no reason to uninstall the trap at all, it works just as
well on the success exit path as an error exit path.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 11:12:41 +02:00
David Gibson
a9b18300b4 test: Remove unused variable FFMPEG_PID_FILE
FFPMPEG_PID_FILE is set (creating a temporary file), then never used.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 11:12:41 +02:00
David Gibson
594c2f9371 test: Group tests by mode then protocol, rather than the reverse
For example, passt/dhcp rather than dhcp/passt.  This is more
consistent with the two_guests and other test groups, and makes some
other cleanups simpler.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 11:12:41 +02:00
David Gibson
4381278b7d test: Use new-style command issue for passt_in_ns tests
Put the pieces together to use the new style context based dispatch for
the passt_in_pasta tests.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 05:32:00 +02:00
David Gibson
87a57156cf test: Use context system for two_guests tests
Now that we have all the pieces we need for issuing commands both into
namespaces and into guests, we can use those to convert the two_guests to
using only the new style context command issue.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 05:32:00 +02:00
David Gibson
56e755ba11 test: Use context system for guest commands
Extends the context system in the test scripts to allow executing commands
within a guest.  Do this without requiring an existing network in the guest
by using socat to run ssh via a vsock connection.

We do need some additional "sleep"s in the tests, because the new
faster dispatch means that sometimes we attempt to connect before
socat has managed to listen.

For now, only use this for the plain "passt" tests.  The "passt_in_ns" and
other tests have additional complications we still need to deal with.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 05:32:00 +02:00
David Gibson
a8a437abd6 test: Extend context system to run commands in namespace for pasta tests
Extend the context system to allow commands to be run in a namespace
created with unshare, and use it for the namespace used in the pasta tests.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 05:32:00 +02:00
David Gibson
a8c32c85d5 test: Add nsholder utility
In our test scripts we need to do some ugly parsing of /proc and/or pstree
output in order to get the PIDs of processes running in namespaces so that
we can connect to those namespaces with nsenter or pasta.

This is actually a pretty tricky problem with standard tools.  To determine
the PID from the outside of the namespace we need to know how the process
of interest is related to the unshare or pasta process (child? one of
several children? grandchild?) as well as then parsing /proc or ps output.
This is slightly awkward now, and will get worse with future changes I'd
like to make to have processes are dispatched.

The obvious solution would be to have the process of interest (which we
control) report its own PID, but that doesn't work easily, because it is in
a PID namepace and sees only its local PID not the global PID we need to
address it from outside.

To handle this, add a small custom tool, "nsholder".  This takes a path
and a mode parameter.  In "hold" mode it will create a unix domain socket
bound to the path and listening.  In "pid" mode it will get the "hold"ing
process's pid via the unix socket using SO_PEERCRED, which translates
between PID namespaces.  In "stop" mode it will send a message to the
socket causing the "hold"ing process to clean up and exit.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 05:32:00 +02:00
David Gibson
2f87265d8b test: Use new-style contexts for passt pane in the pasta and passt tests
Convert the pasta and passt tests to use new-style context execution
for the things that run in the "passt" frame.  Don't touch the
passt_in_ns or two_guests tests yet, because they run passt inside a
namespace which introduces some additional complications we have yet
to handle.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 05:32:00 +02:00
David Gibson
d9b9c252cd test: Issue host commands via context for most tests
Convert most of the tests to use the new-style system for issuing commands
for all host commands.  We leave the distro tests for now: they use
the same pane for both host and guest commands which we'll need some more
things to deal with.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 05:32:00 +02:00
David Gibson
c2f248588b test: Integration of old-style pane execution and new context execution
We're creating a system for tests to more reliably execute commands in
various contexts (e.g. host, guest, namespace).  That transition is going
to happen over a number of steps though, so in the meantime we need to deal
with both the old-style issuing of commands via typing into and screen
scraping tmux panels, and the new-style system for executing commands in
context.

Introduce some transitional helpers which will issue a command via context
if the requested context is initialized, but will otherwise fall back to
the old style tmux panel based method.  Re-implement the various test DSL
commands in terms of these new helpers.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 05:32:00 +02:00
David Gibson
a32df9b6f4 test: Allow a tmux pane to watch commands executed in contexts
We're moving to a new way of the tests dispatching commands to running in
contexts (host, guest, namespace, etc.).  As we make this transition,
though, we still want the user to be able to watch the commands running
in a context, as they previously could from the commands issued in the
pane.

Add a helper to set up a pane to watch a context's log to allow this.  In
some cases we currently issue commands from several different logical
contexts in the same pane, so allow a pane to watch several contexts at
once.  Also use tail's --retry option to allow starting the watch before
we've initialized the context which will be useful in some cases.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 05:32:00 +02:00
David Gibson
3c47b65a64 test: Context execution helpers
For the tests, we need to run commands in various contexts: in the host,
in a guest or in a namespace.  Currently we do this by running each context
in a tmux pane, and using tmux commands to type the commands into the
relevant pane, then screen-scrape the output for the results if we need
them.

This is very fragile, because we have to make various assumptions to parse
the output.  Those can break if a shell doesn't have the prompt we expect,
if the tmux pane is too small or in various other conditions.

This starts some library functions for a new "context" system, that
provides a common way to invoke commands in a given context, in a way that
properly preserves stdout, stderr and the process return code.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 05:32:00 +02:00
David Gibson
4fbd0a8ff9 test: Correctly match "background" with "wait" commands
Our test DSL has a number of paired commands to run something in the
background in a pane, then later to wait for it to complete.  However, in
some of the tests we have these mismatched - starting a command in one
pane, then waiting for it in another.

We appear to get away with this for some reason, but it's not correct and
future changes make it cause more problems.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 05:32:00 +02:00
David Gibson
ef6da15732 Allow --userns when pasta spawns a command
Currently --userns is only allowed when pasta is attaching to an existing
netns or PID, and is prohibited when creating a new netns by spawning a
command or shell.

With the new handling of userns, this check isn't neccessary.  I'm not sure
if there's any use case for --userns with a spawned command, but it's
strictly more flexible and requires zero extra code, so we might as well.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 05:31:51 +02:00
David Gibson
eed17a47fe Handle userns isolation and dropping root at the same time
passt/pasta can interact with user namespaces in a number of ways:
   1) With --netns-only we'll remain in our original user namespace
   2) With --userns or a PID option to pasta we'll join either the given
      user namespace or that of the PID
   3) When pasta spawns a shell or command we'll start a new user namespace
      for the command and then join it
   4) With passt we'll create a new user namespace when we sandbox()
      ourself

However (3) and (4) turn out to have essentially the same effect.  In both
cases we create one new user namespace.  The spawned command starts there,
and passt/pasta itself will live there from sandbox() onwards.

Because of this, we can simplify user namespace handling by moving the
userns handling earlier, to the same point we drop root in the original
namespace.  Extend the drop_user() function to isolate_user() which does
both.

After switching UID and GID in the original userns, isolate_user() will
either join or create the userns we require.  When we spawn a command with
pasta_start_ns()/pasta_setup_ns() we no longer need to create a userns,
because we're already made one.  sandbox() likewise no longer needs to
create (or join) an userns because we're already in the one we need.

We no longer need c->pasta_userns_fd, since the fd is only used locally
in isolate_user().  Likewise we can replace c->netns_only with a local
in conf(), since it's not used outside there.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 05:31:51 +02:00
David Gibson
d9f889a55a Correctly handle --netns-only in pasta_start_ns()
--netns-only is supposed to make pasta use only a network namespace, not
a user namespace.  However, pasta_start_ns() has this backwards, and if
--netns-only is specified it creates a user namespace but *not* a network
namespace.  Correct this.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 05:31:51 +02:00
David Gibson
fc1be3d5ab Clean up and rename conf_ns_open()
conf_ns_open() opens file descriptors for the namespaces pasta needs, but
it doesnt really have anything to do with configuration any more.  For
better clarity, move it to pasta.c and rename it pasta_open_ns().  This
makes the symmetry between it and pasta_start_ns() more clear, since these
represent the two basic ways that pasta can operate, either attaching to
an existing namespace/process or spawning a new one.

Since its no longer validating options, the errors it could return
shouldn't cause a usage message.  Just exit directly with an error instead.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 05:31:51 +02:00
David Gibson
e8b19a4bd2 Consolidate validation of pasta namespace options
There are a number of different ways to specify namespaces for pasta to
use.  Some combinations are valid and some are not.  Currently validation
for these is spread across several places: conf_ns_pid() validates PID
options specifically.  Near its callsite in conf() several other checks
are made. Some additional checks are made in conf_ns_open() and finally
theres a check just before the call to pasta_start_ns().

This is quite hard to follow.  Make it easier by putting all the validation
logic together in a new conf_pasta_ns() function, which subsumes
conf_ns_pid().  This reveals that some of the checks were redundant with
each other, so remove those.

For good measure, rename conf_netns() to conf_netns_opt() to make it
clearer its handling just the --netns option specifically, not overall
configuration of the netns.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 05:31:51 +02:00
David Gibson
d72a1e7bb9 Move self-isolation code into a separate file
passt/pasta contains a number of routines designed to isolate passt from
the rest of the system for security.  These are spread through util.c and
passt.c.  Move them together into a new isolation.c file.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 05:31:51 +02:00
David Gibson
5d3b50c100 Safer handling if we can't open /proc/self/uid_map
passt is allowed to run as "root" (UID 0) in a user namespace, but notas
real root in the init namespace.  We read /proc/self/uid_map to determine
if we're in the init namespace or not.

If we're unable to open /proc/self/uid_map we assume we're ok and
continue running as UID 0.  This seems unwise.  The only instances I
can think of where uid_map won't be available are if the host kernel
doesn't support namespaces, or /proc is not mounted.  In neither case
is it safe to assume we're "not really" root and continue (although in
practice we'd likely fail for other reasons pretty soon anyway).

Therefore, fail with an error in this case, instead of carrying on.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 05:31:51 +02:00
David Gibson
80d7012b09 Consolidate determination of UID/GID to run as
Currently the logic to work out what UID and GID we will run as is spread
across conf().  If --runas is specified it's handled in conf_runas(),
otherwise it's handled by check_root(), which depends on initialization of
the uid and gid variables by either conf() itself or conf_runas().

Make this clearer by putting all the UID and GID logic into a single
conf_ugid() function.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 05:31:51 +02:00
David Gibson
10c6347747 Split checking for root from dropping root privilege
check_root() both checks to see if we are root (in the init namespace),
and if we are drops to an unprivileged user.  To make future cleanups
simpler, split the checking for root (now in check_root()) from the actual
dropping of privilege (now in drop_root()).

Note that this does slightly alter semantics.  Previously we would only
setuid() if we were originally root (in the init namespace).  Now we will
always setuid() and setgid(), though it won't actually change anything if
we weren't privileged to begin with.  This also means that we will now
always attempt to switch to the user specified with --runas, even if we
aren't (init namespace) root to begin with.  Obviously this will fail with
an error if we weren't privileged to start with.  --help and the man page
are updated accordingly.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 05:31:51 +02:00
David Gibson
7330ae3abf Don't store UID & GID persistently in the context structure
c->uid and c->gid are first set in conf(), and last used in check_root()
itself called from conf().  Therefore these don't need to be fields in the
long lived context structure and can instead be locals in conf().

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-13 05:31:51 +02:00
Stefano Brivio
e2cae8f1c3 fedora: Escape % characters in spec file's changelog
...rpmbuild otherwise expands valid macro names in changelog entries.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-09-07 11:01:22 +02:00
David Gibson
e5e10aff81 test: Rewrite test_iperf3
test_iperf3() is a pretty inscrutable mess of nested background processes.
It has a number of ugly sleeps needed to wait for things to complete.

Rewrite it to be cleaner:
  * Use the construct (a & b & wait) to run 'a' and 'b' in parallel, but
    then wait for them both to complete before continuing
  * This allows us to wait for both the server and client to finish, rather
    than sleeping
  * Use jq to do all the math we need to get the final result, rather than
    jq followed by some complicated 'bc' mangling

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-07 11:01:22 +02:00
David Gibson
29247d0db6 test: Parameterize run time for throughput performance tests
Currently all the throughput tests are run for 30s.  This is reflected in
both the actual parameters given to the iperf commands, but also in the
matching sleeps in test_iperf3.

Allow this to be adjusted more easily with a new parameter to test_iperf3.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
[sbrivio: Reflect new parameter in comment to test_iperf3()]
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-09-07 11:01:22 +02:00
David Gibson
5c13b511d9 test: Combine iperf3c and iperf3s into a single DSL command
These two commands in the DSL to run an iperf client and server are always
used together, and some of the parameters must match between them.  The
iperf3s must also be run more or less immediately after iperf3c, since
iperf3c will run a client in the background after a sleep and requires a
server to be running before it will work.

A bunch of things can be made cleaner if we make a single DSL command that
runs both sides of the test.  For now make the combined command work
exactly like the two commands together did, warts and all.

This does lose the ability for the DSL scripts to give additional options
to the iperf3 server, but we weren't using that anyway.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-07 11:01:22 +02:00
David Gibson
55679a16af gitignore pidfiles other than passt.pid
The tests now use a number of pidfiles for qemu and pasta as well as
passt.pid.  Broaden the .gitignore file so these aren't unintentially
committed.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-07 11:01:22 +02:00
Stefano Brivio
b2ee37ad38 Makefile: Honour LDFLAGS for binary targets
We don't set any, but we should use them if they are passed in the
environment. On a Fedora Rawhide package build, annocheck
(https://sourceware.org/annobin/) reports:

  Hardened: /usr/bin/passt: FAIL: bind-now test because not linked with -Wl,-z,now

...despite the build system exporting -Wl,-z,now in LDFLAGS.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-07 11:01:10 +02:00
Stefano Brivio
c880747883 test: Wait for systemd-resolved to be ready on Ubuntu 22.04 for s390x
On new Ubuntu 22.04 images, stopping systemd-resolved to get the
dhclient script override resolv.conf doesn't work anymore. I
originally used that hack to avoid introducing a delay which is
needed when running it on TCG.

Keep systemd-resolved running instead, and wait for it to be ready
by retrying to resolve a domain a few times before installing
packages, so that we don't add another ugly delay that might
unnecessarily slow down things even further.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-09-05 14:32:14 +02:00
Stefano Brivio
7ce9fd165f fedora: Add selinux-policy Requires: tag
fedora-review says:

  Note: Directories without known owners:
  /usr/share/selinux/packages/passt, /usr/share/doc/passt,
  /usr/share/selinux, /usr/share/selinux/packages

and selinux-policy owns those two last ones.

While at it, split Requires: tags also for post and preun actions
onto different lines, for consistency.

Reported-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-09-02 18:03:57 +02:00
Stefano Brivio
96dbaf4d96 fedora: Add %dir entries for own SELinux policy directory and documentation
fedora-review says:

  Note: No known owner of /usr/share/selinux/packages/passt,
  /usr/share/doc/passt

While at it, replace "passt" by "%{name}" in a few places for
consistency.

Reported-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-09-02 17:55:23 +02:00
Stefano Brivio
bac7dfebe4 conf: Fix getopt_long() optstring for current semantics of -D, -S, -p
Declaring them as required_argument in the longopts array specifies
validation, but doesn't affect how optind is increased after parsing
their values.

Currently, passing one of these options as last option causes pasta
to handle their own values as path to a binary to execute.

Fixes: aae2a9bbf7 ("conf: Use "-D none" and "-S none" instead of missing empty option arguments")
Fixes: bf95322fc1 ("conf: Make the argument to --pcap option mandatory")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-09-02 17:07:45 +02:00
Stefano Brivio
a1c38ffe0a test/README: Requirements for socket buffer sizes and hardware performance events
Performance tests use iperf3(1) with large windows, and these sysctl
entries are needed to run them unmodified.

The passt demo uses perf(1) to report syscall overhead, and that
needs access to hardware performance counters for unprivileged
users.

Reported-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2022-09-02 17:06:46 +02:00
Stefano Brivio
0cb795e432 podman, slirp4netns.sh: Use --netns option on pasta's command line
...instead of PATH. This seems to be the only change needed in
existing pasta integrations after patch:

  Use explicit --netns option rather than multiplexing with PID

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2022-08-30 19:43:31 +02:00
Stefano Brivio
b6742d173c contrib: Rebase Podman patch to latest upstream
Trivial conflicts in man pages only.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-08-30 19:43:31 +02:00
David Gibson
1392bc5ca0 Allow pasta to take a command to execute
When not given an existing PID or network namspace to attach to, pasta
spawns a shell.  Most commands which can spawn a shell in an altered
environment can also run other commands in that same environment, which can
be useful in automation.

Allow pasta to do the same thing; it can be given an arbitrary command to
run in the network and user namespace which pasta creates.  If neither a
command nor an existing PID or netns to attach to is given, continue to
spawn a default shell, as before.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-08-30 19:43:31 +02:00
David Gibson
c188736cd8 Use explicit --netns option rather than multiplexing with PID
When attaching to an existing namespace, pasta can take a PID or the name
or path of a network namespace as a non-option parameter.  We disambiguate
based on what the parameter looks like.  Make this more explicit by using
a --netns option for explicitly giving the path or name, and treating a
non-option argument always as a PID.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
[sbrivio: Fix typo in man page]
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-08-30 19:43:31 +02:00
David Gibson
9e0dbc8948 More deterministic detection of whether argument is a PID, PATH or NAME
pasta takes as its only non-option argument either a PID to attach to the
namespaces of, a PATH to a network namespace or a NAME of a network
namespace (relative to /run/netns).  Currently to determine which it is
we try all 3 in that order, and if anything goes wrong we move onto the
next.

This has the potential to cause very confusing failure modes.  e.g. if the
argument is intended to be a network namespace name, but a (non-namespace)
file of the same name exists in the current directory.

Make behaviour more predictable by choosing how to treat the argument based
only on the argument's contents, not anything else on the system:
  - If it's a decimal integer treat it as a PID
  - Otherwise, if it has no '/' characters, treat it as a netns name
    (ip-netns doesn't allow '/' in netns names)
  - Otherwise, treat it as a netns path

If you want to open a persistent netns in the current directory, you can
use './netns'.

This also allows us to split the parsing of the PID|PATH|NAME option from
the actual opening of the namespaces.  In turn that allows us to put the
opening of existing namespaces next to the opening of new namespaces in
pasta_start_ns.  That makes the logical flow easier to follow and will
enable later cleanups.

Caveats:
 - The separation of functions mean we will always generate the basename
   and dirname for the netns_quit system, even when using PID namespaces.
   This is pointless, since the netns_quit system doesn't work for non
   persistent namespaces, but is harmless.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-08-30 19:43:31 +02:00
David Gibson
70389d3640 Move ENOENT error message into conf_ns_opt()
After calling conf_ns_opt() we check for -ENOENT and print an error
message, but conf_ns_opt() prints messages for other errors itself.  For
consistency move the ENOENT message into conf_ns_opt() as well.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-08-30 19:43:31 +02:00
David Gibson
8de488892f Remove --nsrun-dir option
pasta can identify a netns as a "name", which is to say a path relative to
(usually) /run/netns, which is the place that ip(8) creates persistent
network namespaces.  Alternatively a full path to a netns can be given.

The --nsrun-dir option allows the user to change the standard path where
netns names are resolved.  However, there's no real point to this, if the
user wants to override the location of the netns, they can just as easily
use the full path to specify the netns.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-08-30 19:43:31 +02:00
David Gibson
ff1ac78a5e Correct manpage for --userns
The man page states that the --userns option can be given either as a path
or as a name relative to --nsrun-dir.  This is not correct: as the name
suggests --nsrun-dir is (correctly) used only for *netns* resolution, not
*userns* resolution.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2022-08-30 19:43:31 +02:00