If we use a template interface without a gateway on the default
route, we can still offer almost complete functionality, except that,
of course, we can't map the gateway address to the outer namespace or
host, and that we have no obvious server address or identifier for
use in DHCP's siaddr and option 54 (Server identifier, mandatory).
Continue, if we have a default route but no default gateway, and
imply --no-map-gw and --no-dhcp in that case. NDP responder and
DHCPv6 should be able to work as usual because we require a
link-local address to be present, and we'll fall back to that.
Together with the previous commits implementing an actual copy of
routes from the outer namespace, this should finally fix the
operation of 'pasta --config-net' for cases where we have a default
route on the host, but no default gateway, as it's the case for
tap-style routes, including typical Wireguard endpoints.
Reported-by: me@yawnt.com
Link: https://bugs.passt.top/show_bug.cgi?id=49
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
This reverts commit 7656a6f888: now, by
default, we copy all the routes associated to the outbound interface
into the routing table of the container, so there's no need for this
horrible workaround anymore.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Use the newly-introduced NL_DUP mode for nl_route() to copy all the
routes associated to the template interface in the outer namespace,
unless --no-copy-routes (also implied by -g) is given.
This option is introduced as deprecated right away: it's not expected
to be of any use, but it's helpful to keep it around for a while to
debug any suspected issue with this change.
Otherwise, we can't use default gateways which are not, address-wise,
on the same subnet as the container, as reported by Callum.
Reported-by: Callum Parsey <callum@neoninteger.au>
Link: https://github.com/containers/podman/issues/18539
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Instead of just fetching the default gateway and configuring a single
equivalent route in the target namespace, on 'pasta --config-net', it
might be desirable in some cases to copy the whole set of routes
corresponding to a given output interface.
For instance, in:
https://github.com/containers/podman/issues/18539
IPv4 Default Route Does Not Propagate to Pasta Containers on Hetzner VPSes
configuring the default gateway won't work without a gateway-less
route (specifying the output interface only), because the default
gateway is, somewhat dubiously, not on the same subnet as the
container.
This is a similar case to the one covered by commit 7656a6f888
("conf: Adjust netmask on mismatch between IPv4 address/netmask and
gateway"), and I'm not exactly proud of that workaround.
We also have:
https://bugs.passt.top/show_bug.cgi?id=49
pasta does not work with tap-style interface
for which, eventually, we should be able to configure a gateway-less
route in the target namespace.
Introduce different operation modes for nl_route(), including a new
NL_DUP one, not exposed yet, which simply parrots back to the kernel
the route dump for a given interface from the outer namespace, fixing
up flags and interface indices on the way, and requesting to add the
same routes in the target namespace, on the interface we manage.
For n routes we want to duplicate, send n identical netlink requests
including the full dump: routes might depend on each other and the
kernel processes RTM_NEWROUTE messages sequentially, not atomically,
and repeating the full dump naturally resolves dependencies without
the need to actually calculate them.
I'm not kidding, it actually works pretty well.
Link: https://github.com/containers/podman/issues/18539
Link: https://bugs.passt.top/show_bug.cgi?id=49
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
In pasta_wait_for_ns(), open() failing with ENOENT is expected: we're
busy-looping until the network namespace appears. But any other
failure is not something we're going to recover from: return right
away if we don't get either success or ENOENT.
Now that pasta_wait_for_ns() can actually fail, handle that in
pasta_start_ns() by reporting the issue and exiting.
Looping on EPERM, when pasta doesn't actually have the permissions to
join a given namespace, isn't exactly a productive thing to do.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
If pasta spawns a child process while running as UID 0, which is only
allowed from a non-init namespace, we need to keep CAP_SETFCAP before
pasta_start_ns() is called: otherwise, starting from Linux 5.12, we
won't be able to update /proc/self/uid_map with the intended mapping
(from 0 to 0). See user_namespaces(7).
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
If we want /proc contents to be consistent after pasta spawns a child
process in a new PID namespace (only for operation without a
pre-existing namespace), we need to mount /proc after the clone(2)
call with CLONE_NEWPID, and we enable the child to do that by
passing, in the same call, the CLONE_NEWNS flag, as described by
pid_namespaces(7).
This is not really a remount: in fact, passing MS_REMOUNT to mount(2)
would make the call fail. We're in another mount namespace now, so
it's a fresh mount that has the effect of hiding the existing one.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
We'll need this in isolate_initial(). While at it, don't rely on
BUFSIZ: the earlier issue we had with musl reminded me it's not a
magic "everything will fit" value. Size the read buffer to what we
actually need from uid_map, and check for the final newline too,
because uid_map is organised in lines.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
When we receive packets from the tap side, we update the addr_seen fields
to reflect the last known address of the guest or ns. For ip4.addr_seen
we, sensibly, only update if the address we've just seen isn't 0 (0.0.0.0).
This case can occur during early DHCP transactions.
We have no equivalent case for IPv6. We're less likely to hit this,
because DHCPv6 uses link-local addresses, however we can see an source
address of :: with certain multicast operations. This can bite us if we
try to make an incoming connection very early after starting pasta with
--config-net: we may have only seen some of those multicast packets,
updated addr_seen to :: and not had any "real" packets to update it to a
global address. I've seen this with some of the avocado test conversions.
In any case, it can never make sense to update addr_seen to ::, so
explicitly exclude that case.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Valtteri reports that if SIGPIPE already has a disposition set by the
parent process, such as systemd with the default setting of
IgnoreSIGPIPE=yes, signal() will return the previous value, not zero,
and this is not an error: check for SIG_ERR instead.
While at it, split messages for failures of sigaction() and signal(),
and report the actual error.
Reported-by: Valtteri Vuorikoski <vuori@notcom.org>
Fixes: 8534be076c ("Catch failures when installing signal handlers")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
If we enter a mount namespace with nstool exec our working directory will
be changed to / in the new mount ns. This is surprising if we haven't
actually altered any mounts yet in the new ns. Instead, change the working
directory to match that of the holder process in this situation.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This is possible useful in nstool info and has further uses for nstool
exec.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Using this, rather than using "nstool info" to get the pid then manually
connecting with nsenter makes things a little simpler.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Unlike ${DEBUG} we don't initialize ${TRACE} to 0 if not set, which cases
failures when testing it later. That failure acts as though it is false,
however it emits spurious errors in script.log, which can make it harder to
spot real errors.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This allows you to run commands within a user namespace with the
privilege that comes from owning that userns.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This combines nstool info -pw <sock> with nsenter with various options for
a more convenient and less verbose of entering existing nstool managed
namespaces.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Will make things a bit less verbose in future.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
So that we'll probably give a better error if you point it at something
that's not an nstool hold control socket.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Give nstool the ability to detect what namespaces the target process is in,
relative to where it's called. That is, those namespace types for which
the target is not in the same namespace as the caller. For now, just
print this information with "info", which can be useful for debugging.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
The new subcommand gives more information about the holder process and its
namespace, and may be further extended in future. Add some options which
give the old behaviour for existing scripts.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This will make it easier to differentiate the options to those commands
further in future.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Having the "subcommand" first is more conventional and will make it more
natural for future extensions I have planned.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
In preparation for extending what it does.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
context_run() has a race condition if two commands are run in close
proximity (generally involving at least one in the background). Because we
always use the same name for the temporary fifo files, if another command
is issued while the fifos for the first still exist, mkfifo will fail,
typically causing the entire test script to jam.
Create unique names for the temporary fifos to avoid this problem.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
In practical terms, passt doesn't benefit from the additional
protection offered by the AGPL over the GPL, because it's not
suitable to be executed over a computer network.
Further, restricting the distribution under the version 3 of the GPL
wouldn't provide any practical advantage either, as long as the passt
codebase is concerned, and might cause unnecessary compatibility
dilemmas.
Change licensing terms to the GNU General Public License Version 2,
or any later version, with written permission from all current and
past contributors, namely: myself, David Gibson, Laine Stump, Andrea
Bolognani, Paul Holzinger, Richard W.M. Jones, Chris Kuhn, Florian
Weimer, Giuseppe Scrivano, Stefan Hajnoczi, and Vasiliy Ulyanov.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
That was meant to be an example, and I just dropped it in the
previous commit -- passt.if should be more than enough as a possible
example.
Reported-by: Carl G. <carlg@fedoraproject.org>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2182145
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This was meant to be an example, but I managed to add syntax errors
to it. Drop it altogether.
Reported-by: Carl G. <carlg@fedoraproject.org>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2182145
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Somebody might want to bind listening sockets to a specific
interface, but not a specific address, and there isn't really a
reason to prevent that. For example:
-t %eth0/2022
Alternatively, we support options such as -t 0.0.0.0%eth0/2022 and
-t ::%eth0/2022, but not together, for the same port.
Enable this kind of syntax and add examples to the man page.
Reported-by: Paul Holzinger <pholzing@redhat.com>
Link: https://github.com/containers/podman/issues/14425#issuecomment-1485192195
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Since commit cc6d8286d1 ("tcp: Reset ACK_FROM_TAP_DUE flag only as
needed, update timer"), we don't clear ACK_FROM_TAP_DUE whenever we
process an ACK segment, but, more correctly, only if we're really not
waiting for a further ACK segment, that is, only if the acknowledged
sequence matches what we sent.
In the new function implementing this, tcp_update_seqack_from_tap(),
we also reset the retransmission counter and store the updated ACK
sequence. Both should be done iff forward progress is acknowledged,
implied by the fact that the new ACK sequence is greater than the
one we previously stored.
At that point, it looked natural to also include the statements that
clear and set the ACK_FROM_TAP_DUE flag inside the same conditional
block: if we're not making forward progress, the need for an ACK, or
lack thereof, should remain unchanged.
There might be cases where this isn't true, though: without the
previous commit 4e73e9bd65 ("tcp: Don't special case the handling
of the ack of a syn"), this would happen if a tap-side client
initiated a connection, and the server didn't send any data.
At that point we would never, in the established state of the
connection, call tcp_update_seqack_from_tap() with reported forward
progress.
That issue itself is fixed by the previous commit, now, but clearing
ACK_FROM_TAP_DUE only on ACK sequence progress doesn't really follow
any logic.
Clear the ACK_FROM_TAP_DUE flag regardless of reported forward
progress. If we clear it when it's already unset, conn_flag() will do
nothing with it.
This doesn't fix any known functional issue, rather a conceptual one.
Fixes: cc6d8286d1 ("tcp: Reset ACK_FROM_TAP_DUE flag only as needed, update timer")
Reported-by: David Gibson <david@gibson.dropbear.id.au>
Analysed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
TCP treats the SYN packets as though they occupied 1 byte in the logical
data stream described by the sequence numbers. That is, the very first ACK
(or SYN-ACK) each side sends should acknowledge a sequence number one
greater than the initial sequence number given in the SYN or SYN-ACK it's
responding to.
In passt we were tracking that by advancing conn->seq_to_tap by one when
we send a SYN or SYN-ACK (in tcp_send_flag()). However, we also
initialized conn->seq_ack_from_tap, representing the acks we've already
seen from the tap side, to ISN+1, meaning we treated it has having
acknowledged the SYN before it actually did.
There were apparently reasons for this in earlier versions, but it causes
problems now. Because of this when we actually did receive the initial ACK
or SYN-ACK, we wouldn't see the acknoweldged serial number as advancing,
and so wouldn't clear the ACK_FROM_TAP_DUE flag.
In most cases we'd get away because subsequent packets would clear the
flag. However if one (or both) sides didn't send any data, the other side
would (correctly) keep sending ISN+1 as the acknowledged sequence number,
meaning we would never clear the ACK_FROM_TAP_DUE flag. That would mean
we'd treat the connection as if we needed to retransmit (although we had
0 bytes to retransmit), and eventaully (after around 30s) reset the
connection due to too many retransmits. Specifically this could cause the
iperf3 throughput tests in the testsuite to fail if set for a long enough
test period.
Correct this by initializing conn->seq_ack_from_tap to the ISN and only
advancing it when we actually get the first ACK (or SYN-ACK).
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Comments suggest that this should only be called for an ESTABLISHED
connection. However, it's non-trivial to ascertain that from the actual
control flow in the caller. Add an ASSERT() to make it very clear that
this is only called in ESTABLISHED state.
In fact, there were some circumstances where it could be called on a CLOSED
connection. In a sense that is "established", but with that assert this
does require specific (trivial) handling to avoid a spurious abort().
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This is mostly symmetric with commit cc6d8286d1 ("tcp: Reset
ACK_FROM_TAP_DUE flag only as needed, update timer"): we shouldn't
reset the ACK_TO_TAP_DUE flag on any inbound ACK segment, but only
once we acknowledge everything we received from the guest or the
container.
If we don't, a client might unnecessarily hold off further data,
especially during slow start, and in general we won't converge to the
usable bandwidth.
This is very visible especially with traffic tests on links with
non-negligible latency, such as in the reported issue. There, a
public iperf3 server sometimes aborts the test due do what appears to
be a low iperf3's --rcv-timeout (probably less than a second). Even
if this doesn't happen, the throughput will converge to a fraction of
the usable bandwidth.
Clear ACK_TO_TAP_DUE if we acknowledged everything, set it if we
didn't, and reschedule the timer in case the flag is still set as the
timer expires.
While at it, decrease the ACK timer interval to 10ms.
A 50ms interval is short enough for any bandwidth-delay product I had
in mind (local connections, or non-local connections with limited
bandwidth), but here I am, testing 1gbps transfers to a peer with
100ms RTT.
Indeed, we could eventually make the timer interval dependent on the
current window and estimated bandwidth-delay product, but at least
for the moment being, 10ms should be long enough to avoid any
measurable syscall overhead, yet usable for any real-world
application.
Reported-by: Lukas Mrtvy <lukas.mrtvy@gmail.com>
Link: https://bugs.passt.top/show_bug.cgi?id=44
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Fix a copy and paste typo I added in commit 5474bc5485 ("tcp,
tcp_splice: Get rid of false positive CWE-394 Coverity warning from
fls()") and --debug altogether.
Fixes: 5474bc5485 ("tcp, tcp_splice: Get rid of false positive CWE-394 Coverity warning from fls()")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
da46fdac "tcp: Suppress knownConditionTrueFalse cppcheck false positive"
introduced a suppression to work around a cppcheck bug causing a false
positive warning. However, the suppression will itself cause a spurious
unmatchedSuppression warning if used with a version of cppcheck from before
the bug was introduced. That includes the packaged version of cppcheck in
Fedora.
Suppress the unmatchedSuppression as well.
Fixes: da46fdac36 ("tcp: Suppress knownConditionTrueFalse cppcheck false positive")
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Commit 89e38f55 "treewide: Fix header includes to build with musl" added
extra #includes to work with musl. Unfortunately with the cppcheck version
I'm using (cppcheck-2.9-1.fc37.x86_64 in Fedora 37) this causes weird false
positives: specifically cppcheck seems to hit a #error in <bits/unistd.h>
complaining about including it directly instead of via <unistd.h> (which is
not something we're doing).
I have no idea why that would be happening; but I'm guessing it has to be
a bug in the cpp implementation in that cppcheck version. In any case,
it's possible to work around this by moving the include of <unistd.h>
before the include of <signal.h>. So, do that.
Fixes: 89e38f5540 ("treewide: Fix header includes to build with musl")
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
When I reworked udp_init() to move most of the port binding logic
to conf_ports, I accidentally dropped this bit of automatic port
detection (and binding) at start-up.
On -U auto, in pasta mode, udp_sock_init_ns() binds ports in the
namespace that correspond to ports bound in the init namespace,
but on -u auto, nothing actually happens after port detection.
Add udp_sock_init_init() to deal with this, and while at it fix
the comment to udp_sock_init_ns(): the latter takes care of
outbound "connections".
This is currently not covered by tests, and the UDP port needs to
be already bound in the namespace when pasta starts (periodic
detection for UDP is a missing feature at the moment). It can be
checked like this:
$ unshare -rUn
# echo $$
590092
# socat -u UDP-LISTEN:5555 STDOUT
$ pasta -q -u auto 590092
$ echo "test" | socat -u STDIN UDP:localhost:5555
Reported-by: Paul Holzinger <pholzing@redhat.com>
Fixes: 3c6ae62510 ("conf, tcp, udp: Allow address specification for forwarded ports")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
The logic in tcp_timer() was inverted. fwd_out should expose the host
ports in the ns. Therfore it must read the ports on the host and then
bind them in the netns. The same for fwd_in which checks ports in the
ns and then exposes them on the host.
Note that this only fixes tcp ports, udp does not seems to work at all
right now with the auto mode.
Signed-off-by: Paul Holzinger <pholzing@redhat.com>
Fixes: 1128fa03fe ("Improve types and names for port forwarding configuration")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Instead of:
https://fedoraproject.org/wiki/SELinux_Policy_Modules_Packaging_Draft
follow this:
https://fedoraproject.org/wiki/PackagingDrafts/SELinux_Independent_Policy
which seems to make more sense and fixes the issue that, on a fresh
install, without a reboot, the file contexts for the binaries are not
actually updated.
In detail:
- labels are refreshed using the selinux_relabel_pre and
selinux_relabel_post on install, upgrade, and uninstall
- use the selinux_modules_install and selinux_modules_uninstall
macros, instead of calling 'semodule' directly (no functional
changes in our case)
- require the -selinux package on SELinux-enabled environments and if
the current system policy is "targeted"
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
A cross-architecture build might pass a target-specific CC on 'make',
and not on 'make install', and this is what happens in Debian
cross-qa tests.
Given that we select binaries to be installed depending on the target
architecture, this means we would build AVX2 binaries in any case on
a x86_64 build machine.
By overriding TARGET in package build rules, we can tell the Makefile
about the target architecture, also for the 'install' (Makefile)
target.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
By default, 65520 bytes are advertised, and zero disables DHCP and
NDP options.
Fixes: ec2b58ea4d ("conf, dhcp, ndp: Fix message about default MTU, make NDP consistent")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
On X32 (ILP32 using AMD64 system call ABI) and glibc,
struct timespec::tv_nsec is __syscall_slong_t and not a long int, see
also https://sourceware.org/bugzilla/show_bug.cgi?id=16437 and
timespec(3type). Fine, we could cast that down to long and be done
with it.
But it turns out that also time_t (not guaranteed to be equivalent to
any type) is a long long int, and there we can't downcast.
To keep it simple, cast both to long long int, and change formats to
%lli, to avoid format warnings from gcc.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
