commit a469fc393f ("tcp, tap: Don't increase tap-side sequence counter for dropped frames")
delayed update of conn->seq_to_tap until the moment the corresponding
frame has been successfully pushed out. This has the advantage that we
immediately can make a new attempt to transmit a frame after a failed
trasnmit, rather than waiting for the peer to later discover a gap and
trigger the fast retransmit mechanism to solve the problem.
This approach has turned out to cause a problem with spurious sequence
number updates during peer-initiated retransmits, and we have realized
it may not be the best way to solve the above issue.
We now restore the previous method, by updating the said field at the
moment a frame is added to the outqueue. To retain the advantage of
having a quick re-attempt based on local failure detection, we now scan
through the part of the outqueue that had do be dropped, and restore the
sequence counter for each affected connection to the most appropriate
value.
Signed-off-by: Jon Maloy <jmaloy@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Now:
- we don't open the PID file in main() anymore
- PID file and AF_UNIX socket are opened by pidfile_open() and
tap_sock_unix_open()
- write_pidfile() becomes pidfile_write()
Reported-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Acked-by: Richard W.M. Jones <rjones@redhat.com>
We have pidfile_fd now, pid_file_fd would be quite ugly.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Otherwise, if the user runs us as root, and gives us paths that are
only accessible by root, we'll fail to open them, which might in turn
encourage users to change permissions or ownerships: definitely a bad
idea in terms of security.
Reported-by: Minxi Hou <mhou@redhat.com>
Reported-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Acked-by: Richard W.M. Jones <rjones@redhat.com>
We won't call it from main() any longer: move it.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
As I'm adding pidfile_open() in the next patch. The function comment
didn't match, by the way.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
We'll need to open and bind the socket a while before listening to it,
so split that into two different functions. No functional changes
intended.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
This is a remnant from the time we kept access to the original
filesystem and we could reinitialise the listening AF_UNIX socket.
Since commit 0515adceaa ("passt, pasta: Namespace-based sandboxing,
defer seccomp policy application"), however, we can't re-bind the
listening socket once we're up and running.
Drop the -1 initalisation and the corresponding check.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
It has nothing to do with tap_sock_unix_init(). It used to be there as
that function could be called multiple times per passt instance, but
it's not the case anymore.
This also takes care of the fact that, with --fd, we wouldn't set the
initial MAC address, so we would need to wait for the guest to send us
an ARP packet before we could exchange data.
Fixes: 6b4e68383c ("passt, tap: Add --fd option")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Richard W.M. Jones <rjones@redhat.com>
libguestfs tools have a good reason to run as root: if the guest image
is owned by root, it would be counterproductive to encourage users to
invoke them as non-root, as it would require changing permissions or
ownership of the image file.
And if they run as root, we'll start as root, too. Warn users we'll
switch to 'nobody', but don't tell them what to do.
Reported-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
When we retrieve or copy host addresses we can include deprecated
addresses, which is not what we want. Adjust our logic to exclude them.
Similarly our tests can retrieve deprecated addresses, so exclude them
there too.
I hit this in practice because my router sometimes temporarily advertises
an fd00:: prefix before the real delegated IPv6 prefix. The deprecated
address can hang around for some time messing up my tests.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
We recently introduced this field to keep track of which side of a TCP flow
is the guest/tap facing one. Now that we generically record which pif each
side of each flow is connected to, we can easily derive that, and no longer
need to keep track of it explicitly.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Currently we have no generic information flows apart from the type and
state, everything else is specific to the flow type. Start introducing
generic flow information by recording the pifs which the flow connects.
To keep track of what information is valid, introduce new flow states:
INI for when the initiating side information is complete, and TGT for
when both sides information is complete, but we haven't chosen the
flow type yet. For now, these states don't do an awful lot, but
they'll become more important as we add more generic information.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Each flow in the flow table has two sides, 0 and 1, representing the
two interfaces between which passt/pasta will forward data for that flow.
Which side is which is currently up to the protocol specific code: TCP
uses side 0 for the host/"sock" side and 1 for the guest/"tap" side, except
for spliced connections where it uses 0 for the initiating side and 1 for
the target side. ICMP also uses 0 for the host/"sock" side and 1 for the
guest/"tap" side, but in its case the latter is always also the initiating
side.
Make this generically consistent by always using side 0 for the initiating
side and 1 for the target side. This doesn't simplify a lot for now, and
arguably makes TCP slightly more complex, since we add an extra field to
the connection structure to record which is the guest facing side. This is
an interim change, which we'll be able to remove later.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>q
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Flows move over several different states in their lifetime. The rules for
these are documented in comments, but they're pretty complex and a number
of the transitions are implicit, which makes this pretty fragile and
error prone.
Change the code to explicitly track the states in a field. Make all
transitions explicit and logged. To the extent that it's practical in C,
enforce what can and can't be done in various states with ASSERT()s.
While we're at it, tweak the docs to clarify the restrictions on each state
a bit.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This adds some extra inany helpers for comparing an inany address to
addresses of a specific family (including special addresses), and building
an inany from an IPv4 address (either statically or at runtime).
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
The flow dispatches deferred and timer handling for flows centrally, but
needs to call into protocol specific code for the handling of individual
flows. Currently this passes a general union flow *. It makes more sense
to pass the specific relevant flow type structure. That brings the check
on the flow type adjacent to casting to the union variant which it tags.
Arguably, this is a slight abstraction violation since it involves the
generic flow code using protocol specific types. It's already calling into
protocol specific functions, so I don't think this really makes any
difference.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
When reporting errors, we sometimes want to show a relevant socket address.
Doing so by extracting the various relevant fields can be pretty awkward,
so introduce a sockaddr_ntop() helper to make it simpler. For now we just
have one user in tcp.c, but I have further upcoming patches which can make
use of it.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Commit b686afa2 introduced the invalid apparmor rule
`mount options=(rw, runbindable) /,` since runbindable mount rules
cannot have a source.
Therefore running aa-logprof/aa-genprof will trigger errors (see
https://bugs.launchpad.net/ubuntu/+source/apparmor/+bug/2065685)
$ sudo aa-logprof
ERROR: Operation {'runbindable'} cannot have a source. Source = AARE('/')
This patch fixes it to the intended behavior.
Link: https://bugs.launchpad.net/ubuntu/+source/apparmor/+bug/2065685
Fixes: b686afa23e ("apparmor: Explicitly pass options we use while remounting root filesystem")
Signed-off-by: Maxime Bélair <maxime.belair@canonical.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
For some unknown reason "owner" makes it impossible to open bind mounted
netns references as apparmor denies it. In the kernel denied log entry
we see ouid=0 but it is not clear why that is as the actual file is
owned by the real (rootless) user id.
In abstractions/pasta there is already `@{run}/user/@{uid}/**` without
owner set for the same reason as this path contains the netns path by
default when running under Podman.
Fixes: 72884484b0 ("apparmor: allow read access on /tmp for pasta")
Signed-off-by: Paul Holzinger <pholzing@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
clang-tidy 18.1.1 in Fedora 40 complains about every #define of an integral
value, suggesting it be converted to an enum. Although that's certainly
possible, it's of dubious value and results in some awkward arrangements on
out codebase. Suppress it globally.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
In conf() we temporarily set the forwarding mode variables to 0 - an
invalid value, so that we can check later if they've been set by the
intervening logic. clang-tidy 18.1.1 in Fedora 40 now complains about
this. Satisfy it by giving an name in the enum to the 0 value.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
We take care of this in nl_addr_dup(): if the interface index
associated to an address doesn't match the selected host interface
(ifa->ifa_index != ifi_src), we don't copy that address.
But for routes, we just unconditionally update the interface index to
match the index in the target namespace, even if the source interface
didn't match.
This might happen in two cases: with a pre-4.20 kernel without support
for NETLINK_GET_STRICT_CHK, which won't filter routes based on the
interface we pass in the request, as reported by runsisi, and any
kernel with support for multipath routes where any of the nexthops
refers to an unrelated host interface.
In both cases, check the index of the source interface, and avoid
copying unrelated routes.
Reported-by: runsisi <runsisi@hust.edu.cn>
Link: https://bugs.passt.top/show_bug.cgi?id=86
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Tested-by: runsisi <runsisi@hust.edu.cn>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
The podman CI on debian runs tests based on /tmp but pasta is failing
there because it is unable to open the netns path as the open for read
access is denied.
Link: https://github.com/containers/podman/issues/22625
Signed-off-by: Paul Holzinger <pholzing@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
In tcp_splice_sock_handler(), if we get EAGAIN on the second splice(),
from pipe to receiving socket, that doesn't necessarily mean that the
pipe is empty: the receiver buffer might be full instead.
Hence, we can't use the 'never_read' flag to decide that there's
nothing to wait for: even if we didn't read anything from the sending
side in a given iteration, we might still have data to send in the
pipe. Use read/written counters, instead.
This fixes an issue where large bulk transfers would occasionally
hang. From a corresponding strace:
0.000061 epoll_wait(4, [{events=EPOLLOUT, data={u32=29442, u64=12884931330}}], 8, 1000) = 1
0.005003 epoll_ctl(4, EPOLL_CTL_MOD, 211, {events=EPOLLIN|EPOLLRDHUP, data={u32=54018, u64=8589988610}}) = 0
0.000089 epoll_ctl(4, EPOLL_CTL_MOD, 115, {events=EPOLLIN|EPOLLRDHUP, data={u32=29442, u64=12884931330}}) = 0
0.000081 splice(211, NULL, 151, NULL, 1048576, SPLICE_F_MOVE|SPLICE_F_NONBLOCK) = -1 EAGAIN (Resource temporarily unavailable)
0.000073 splice(150, NULL, 115, NULL, 1048576, SPLICE_F_MOVE|SPLICE_F_NONBLOCK) = 1048576
0.000087 splice(211, NULL, 151, NULL, 1048576, SPLICE_F_MOVE|SPLICE_F_NONBLOCK) = -1 EAGAIN (Resource temporarily unavailable)
0.000045 splice(150, NULL, 115, NULL, 1048576, SPLICE_F_MOVE|SPLICE_F_NONBLOCK) = 520415
0.000060 splice(211, NULL, 151, NULL, 1048576, SPLICE_F_MOVE|SPLICE_F_NONBLOCK) = -1 EAGAIN (Resource temporarily unavailable)
0.000044 splice(150, NULL, 115, NULL, 1048576, SPLICE_F_MOVE|SPLICE_F_NONBLOCK) = -1 EAGAIN (Resource temporarily unavailable)
0.000044 epoll_wait(4, [], 8, 1000) = 0
we're reading from socket 211 into to the pipe end numbered 151,
which connects to pipe end 150, and from there we're writing into
socket 115.
We initially drop EPOLLOUT from the set of monitored flags for socket
115, because it already signaled it's ready for output. Then we read
nothing from socket 211 (the sender had nothing to send), and we keep
emptying the pipe into socket 115 (first 1048576 bytes, then 520415
bytes).
This call of tcp_splice_sock_handler() ends with EAGAIN on the writing
side, and we just exit this function without setting the OUT_WAIT_1
flag (and, in turn, EPOLLOUT for socket 115). However, it turns out,
the pipe wasn't actually emptied, and while socket 211 had nothing
more to send, we should have waited on socket 115 to be ready for
output again.
As a further step, we could consider not clearing EPOLLOUT at all,
unless the read/written counters match, but I'm first trying to fix
this ugly issue with a minimal patch.
Link: https://github.com/containers/podman/issues/22575
Link: https://github.com/containers/podman/issues/22593
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Currently we have separate arrays for IPv4 and IPv6 which contain the
headers for guest-bound packets, and also the originating socket address.
We can combine these into a single array of "metadata" structures with
space for both pre-cooked IPv4 and IPv6 headers, as well as shared space
for the tap specific header and socket address (using sockaddr_inany).
Because we're using IOVs to separately address the pieces of each frame,
these structures don't need to be packed to keep the headers contiguous
so we can more naturally arrange for the alignment we want.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Currently each tap-bound frame buffer has room for its own ethernet header.
However the ethernet header is always the same for such frames, so now
that we're indirectly referencing the ethernet header via iov, we can use
a single buffer for all of them.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Currently the IPv4 and IPv6 paths unnecessarily use different buffers for
the UDP payload. Now that we're handling the various pieces of the UDP
packets with an iov, we can split the payload part of the buffers off into
its own array shared between IPv4 and IPv6. As well as saving a little
memory, this allows the payload buffers to be neatly page aligned.
With the buffers merged, udp[46]_l2_iov_sock contain exactly the same thing
as each other and can also be merged. Likewise udp[46]_iov_splice can be
merged together.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
For IPv4, UDP checksums are optional and can just be set to 0.
udp_update_hdr4() ignores the checksum field entirely. Since these are set
to 0 during startup, this works as intended for now.
However, we'd like to share payload and UDP header buffers betweem IPv4 and
IPv6, which does calculate UDP checksums. Therefore, for robustness, we
should explicitly set the checksum field to 0 for guest-bound UDP packets.
In the tap_udp4_send() slow path, however, we do allow IPv4 UDP checksums
to be calculated as a compile time option. For consistency, use the same
thing in the udp_update_hdr4() path, which will typically initialize to 0,
but calculate a real checksum if configured to do so.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
We're going to introduce more sharing between the IPv4 and IPv6 buffer
structures. Prepare for this by combinng the initialisation functions.
While we're at it remove the misleading "sock" from the name since these
initialise both tap side and sock side structures.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
When sending to the tap device, currently we assemble the headers and
payload into a single contiguous buffer. Those are described by a single
struct iovec, then a batch of frames is sent to the device with
tap_send_frames().
In order to better integrate the IPv4 and IPv6 paths, we want the IP
header in a different buffer that might not be contiguous with the
payload. To prepare for that, split the UDP packet into an iovec of
buffers. We use the same split that Laurent recently introduced for
TCP for convenience.
This removes the last use of tap_hdr_len_(), tap_frame_base() and
tap_frame_len(), so remove those too.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
During some debugging recently, I wanted to extact a file from a test
guest and found it was tricky, since the ssh-over-vsock setup we had didn't
allow sftp/scp. We can fix this by adding a line to the guest side sshd
config from mbuto. While we're there correct an inaccurate comment.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
tcp_fill_headers[46]() fill most of the headers, but the tap specific
header (the frame length for qemu sockets) is filled in afterwards.
Filling this as well:
* Removes a little redundancy between the tcp_send_flag() and
tcp_data_to_tap() path
* Makes calculation of the correct length a little easier
* Removes the now misleadingly named 'vnet_len' variable in
tcp_send_flag()
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Laurent's recent changes mean we use IO vectors much more heavily in the
TCP code. In many of those cases, and few others around the code base,
individual iovs of these vectors are constructed to exactly cover existing
variables or fields. We can make initializing such iovs shorter and
clearer with a macro for the purpose.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Recent changes to the TCP code (reworking of the buffer handling) have
meant that it now (again) deals explicitly with the MODE_PASST specific
vnet_len field, instead of using the (partial) abstractions provided by the
tap layer.
The abstractions we had don't work for the new TCP structure, so make some
new ones that do: tap_hdr_iov() which constructs an iovec suitable for
containing (just) the TAP specific header and tap_hdr_update() which
updates it as necessary per-packet.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
tcp_fill_headers[46]() compute the L3 packet length from the L4 packet
length, then their caller tcp_l2_buf_fill_headers() converts it back to the
L4 packet length. We can just use the L4 length throughout.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>eewwee
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
At various points we need to track the lengths of a packet including or
excluding various different sets of headers. We don't always use the same
variable names for doing so. Worse in some places we use the same name
for different things: e.g. tcp_fill_headers[46]() use ip_len for the
length including the IP headers, but then tcp_send_flag() which calls it
uses it to mean the IP payload length only.
To improve clarity, standardise on these names:
dlen: L4 protocol payload length ("data length")
l4len: plen + length of L4 protocol header
l3len: l4len + length of IPv4/IPv6 header
l2len: l3len + length of L2 (ethernet) header
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
csum_ip4_header() takes the packet length as a network endian value. In
general it's very error-prone to pass non-native-endian values as a raw
integer. It's particularly bad here because this differs from other
checksum functions (e.g. proto_ipv4_header_psum()) which take host native
lengths.
It turns out all the callers have easy access to the native endian value,
so switch it to use host order like everything else.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
In general, it's much less error-prone to have the endianness of values
implied by the type, rather than just noting it in comments. We can't
always easily avoid it, because C, but we can do so when possible. struct
in_addr and in6_addr are always encoded network endian, so noting it
explicitly isn't useful. Remove them.
In some cases we also have endianness notes on uint8_t parameters, which
doesn't make sense: for a single byte endianness is irrelevant. Remove
those too.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Use of these structures was removed in bb70811183 ("treewide: Packet
abstraction with mandatory boundary checks"). Remove the stale
declarations.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
In some places (well, actually only UDP now) we use struct tap_hdr to
represent both tap backend specific and L2 ethernet headers. Handling
these together seemed like a good idea at the time, but Laurent's changes
in the TCP code working towards vhost-user support suggest that treating
them separately is more useful, more often.
Alter struct tap_hdr to represent only the TAP backend specific headers.
Updated related helpers and the UDP code to match.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
7df624e79 ("checksum: introduce functions to compute the header part
checksum for TCP/UDP") introduced a helper to compute the partial checksum
for the IPv6 pseudo-header used in L4 protocol checksums. It used it in
csum_udp6() for UDP packets, but not in csum_icmp6() for the identical
calculation in csum_icmp6() for ICMPv6 packets.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Somewhat confusingly, RTNH_NEXT(), as defined by <linux/rtnetlink.h>,
doesn't take an attribute length parameter like RTA_NEXT() does, and
I just modelled loops over nexthops after RTA loops, forgetting to
decrease the remaining length we pass to RTNH_OK().
In practice, this didn't cause issue in any of the combinations I
checked, at least without the next patch.
We seem to be the only user of RTNH_OK(): even iproute2 has an
open-coded version of it in print_rta_multipath() (ip/iproute.c).
Introduce RTNH_NEXT_AND_DEC(), similar to RTA_NEXT(), and use it.
Fixes: 6c7623d07b ("netlink: Add support to fetch default gateway from multipath routes")
Fixes: f4e38b5cd2 ("netlink: Adjust interface index inside copied nexthop objects too")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
...not just for a single set address (legacy operation with
--no-copy-addrs). I forgot to add this to nl_addr_dup().
Note that we can have two version of flags: the 8-bit ifa_flags in
ifaddrmsg, and the newer 32-bit version as IFA_FLAGS attribute, which
is given priority if present. Make sure IFA_F_NODAD is set in both.
Without this, a Podman user reports, something on the lines of:
pasta --config-net -- ping -c1 -6 passt.top
would fail as the kernel would start Duplicate Address Detection
once we configure the address, which can't really work (and doesn't
make sense) in this case.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
See the comment to the unnamed enum in linux/if_addr.h, which
currently states:
/*
* Important comment:
* IFA_ADDRESS is prefix address, rather than local interface address.
* It makes no difference for normally configured broadcast interfaces,
* but for point-to-point IFA_ADDRESS is DESTINATION address,
* local address is supplied in IFA_LOCAL attribute.
*
* [...]
*/
if we fetch IFA_ADDRESS, and we have a point-to-point link with a peer
address configured, we'll source the peer address as "our" address,
and refuse to resolve it in arp().
This was reported with pasta and a tun upstream interface configured
by OpenVPN in "p2p" topology: the target namespace will have similar
addresses and routes as the host, which is fine, and will try to
resolve the point-to-point peer address (because it's the default
gateway).
Given that we configure it as our address (only internally, not
visibly in the namespace), we'll fail to resolve that and traffic
doesn't go anywhere.
Note that this is not the case for IPv6: there, IFA_ADDRESS is the
actual, local address of the interface, and IFA_LOCAL is not
necessarily present, so the comment in linux/if_addr.h doesn't apply
either.
Link: https://github.com/containers/podman/issues/22320
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
test/pasta_options/log_to_file checks that pasta truncates its log file
when started. It does that by starting pasta with a log file once, then
starting it again and checking that after the second round, the log file
has only one line: the startup banner from the second invocation.
However, this test will break if the second invocation logs any additional
messages at startup. This can easily happen on a host with multiple
network interfaces due to the "Multiple default route" informational
messages added in 639fdf06e ("netlink: Fix selection of template
interface"). I believe it could also happen on a host without IPv6
connectivity due to the "Couldn't pick external interface" messages, though
I haven't confirmed this.
Make the log file test more robust, by not testing for a single line, but
instead explicitly testing for the PID of the second pasta invocation in
the banner line.
Link: https://bugs.passt.top/show_bug.cgi?id=88
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
test/pasta_options/log_to_file contains a couple of rudimentary tests
where we start pasta with an interactive shell, then immediately exit it.
We can achieve the same thing by using /bin/true as the command to pasta.
This also means that waiting for pasta to start, waiting for the executed
command to complete and for pasta to clean up are all handled by simply
waiting for pasta to complete in the foreground, so there's no need for an
additional sleep.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Commit bb9bf0bb ("tcp, udp: Don't precompute port remappings in epoll
references") changed the epoll reference for UDP sockets to include the
bound port as seen by the socket itself, rather than the bound port it
would be translated to on the guest side. As a side effect, it also means
that udp_tap_map[] is indexed by the bound port on the host side, rather
than on the guest side. This is consistent and a good idea, however we
forgot to account for it when finding the correct outgoing socket for
packets originating in the guest. This means that if forwarding UDP
inbound with a port number change, reply packets would be misdirected.
Fix this by applying the reverse mapping before looking up the socket in
udp_tap_handler(). While we're at it, use 'port' directly instead of
'uref.port' in udp_sock_init(). Those now always have the same value -
failing to realise that is the same error as above.
Reported-by: Laurent Jacquot <jk@lutty.net>
Link: https://bugs.passt.top/show_bug.cgi?id=87
Fixes: bb9bf0bb8f ("tcp, udp: Don't precompute port remappings in epoll references")
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
To be able to provide pointers to TCP headers and IP headers without
worrying about alignment in the structure, split the structure into
several arrays and point to each part of the frame using an iovec array.
Using iovec also allows us to simply ignore the first entry when the
vnet length header is not needed.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
