First off, as we swap endianness for source ports in
udp_fill_data_v{4,6}(), we want host endianness, not network
endianness. It doesn't actually matter if we use htons() or ntohs()
here, but the current version is confusing.
In the IPv4 path, when we remap DNS answers, we already swapped the
endianness as needed for the source port: don't swap it again,
otherwise we'll not map DNS answers for IPv4.
In the IPv6 path, when we remap DNS answers, we want to check that
they came from our upstream DNS server, not the one configured via
--dns-forward (which doesn't even need to exist for this
functionality to work).
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
This is a minor optimisation possibility I spotted while trying to
debug a hang in tap4_handler(): if we run out of space for packet
sequences, it's fine to add packets to an existing per-sequence pool.
We should check the count of packet sequences only once we realise
that we actually need a new packet sequence.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
An n-sized pool, or a pool with n entries, doesn't include index n,
only up to n - 1.
I'm not entirely sure this sanity check actually covers any
practical case, but I spotted this while debugging a hang in
tap4_handler() (possibly due to malformed sequence entries from
qemu).
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Fixes: 745a9ba428 ("pasta: By default, quit if filesystem-bound net namespace goes away")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Since kernel version 5.7, commit c427bfec18f2 ("net: core: enable
SO_BINDTODEVICE for non-root users"), we can bind sockets to
interfaces, if they haven't been bound yet (as in bind()).
Introduce an optional interface specification for forwarded ports,
prefixed by %, that can be passed together with an address.
Reported use case: running local services that use ports we want
to have externally forwarded:
https://github.com/containers/podman/issues/14425
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
This is practical to avoid explicit lifecycle management in users,
e.g. libvirtd, and is trivial to implement.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Coverity now noticed we're checking most lseek() return values, but
not this. Not really relevant, but it doesn't hurt to check we can
actually seek before reading lines.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
In some environments, such as KubeVirt pods, we might not have a
system logger available. We could choose to run in foreground, but
this takes away the convenient synchronisation mechanism derived from
forking to background when interfaces are ready.
Add optional logging to file with -l/--log-file and --log-size.
Unfortunately, this means we need to duplicate features that are more
appropriately implemented by a system logger, such as rotation. Keep
that reasonably simple, by using fallocate() with range collapsing
where supported (Linux kernel >= 3.15, extent-based ext4 and XFS) and
falling back to an unsophisticated block-by-block moving of entries
toward the beginning of the file once we reach the (mandatory) size
limit.
While at it, clarify the role of LOG_EMERG in passt.c.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
This saves some hassle when including passt.h, as we need ETH_ALEN
there.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
This originated as a result of copy and paste to introduce a second
stage for processing options related to port forwarding, has already
bitten David in the past, and just gave me hours of fun.
As a matter of fact, the second set of optstring assignments was
already incorrect, but it didn't matter because the first one was
more restrictive, not allowing optional arguments for -P, -D, -S.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Logging to file is going to add some further complexity that we don't
want to squeeze into util.c.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
To keep this simple, only support tests that have corresponding setup
and teardown functions implied by their path. For example:
./run passt/ndp
will trigger the 'passt' setup and teardown functions.
This is not really elegant, but it looks robust, and while David is
considering proper alternatives, it should be quite useful.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
With gcc 11 and 12, passing -flto, or -flto=auto, and -O2,
intra-procedural optimisation gets rid of a fundamental bit in ndp():
the store of hop_limit in the IPv6 header, before the checksum is
calculated, which on x86_64 looks like this:
ip6hr->hop_limit = IPPROTO_ICMPV6;
b8c0: c6 44 24 35 3a movb $0x3a,0x35(%rsp)
Here, hop_limit is temporarily set to the protocol number, to
conveniently get the IPv6 pseudo-header for ICMPv6 checksum
calculation in memory.
With LTO, the assignment just disappears from the binary.
This is rather visible as NDP messages get a wrong checksum, namely
the expected checksum plus 58, and they're ignored by the guest or
in the namespace, meaning we can't get any IPv6 routes, as reported
by Wenli Quan.
The issue affects a significant number of distribution builds,
including the ones for CentOS Stream 9, EPEL 9, Fedora >= 35,
Mageia Cauldron, and openSUSE Tumbleweed.
As a quick workaround, declare csum_unaligned() as "noipa" for gcc
11 and 12, with -flto and -O2. This disables inlining and cloning,
which causes the assignment to be compiled again.
Leave a TODO item: we should figure out if a gcc issue has already
been reported, and report one otherwise. There's no apparent
justification as to why the store could go away.
Reported-by: Wenli Quan <wquan@redhat.com>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2129713
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Commit c318ffcb4c ("udp: Ignore bogus -Wstringop-overread for
write() from gcc 12.1") uses a gcc pragma to ignore a bogus warning,
which started appearing on gcc 12.1 (aarch64 and x86_64) due to:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103483
...but gcc 12.2 has the same issue. Not just that: if LTO is enabled,
the pragma itself is ignored (this wasn't the case with gcc 12.1),
because of:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80922
Drop the pragma, and assign a frame (in the networking sense) pointer
from the offset of the Ethernet header in the buffer, then pass it to
write() and pcap(), so that gcc doesn't obsess anymore with the fact
that an Ethernet header is 14 bytes and we're sending more than that.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Commit 1a563a0cbd ("passt: Address gcc 11 warnings") works around an
issue where the remote address passed to hash functions is seen as
uninitialised by gcc, with -flto and -O2.
It turns out we get the same exact behaviour on gcc 12.1 and 12.2, so
extend the applicability of the same workaround to gcc 12.
Don't go further than that, though: should the issue reported at:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78993
happen to be fixed in a later version of gcc, we won't need the
noinline attributes anymore. Otherwise, we'll notice.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
It's unclear what original suppressions these unmatchedSuppression
suppressions were supposed to go with. They don't trigger any warnings on
the current code that I can tell, so remove them. If we find a problem
with some cppcheck versions in future, replace them with inline
suppressions so it's clearer exactly where the issue is originating.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
We have a couple of functions that are unused (for now) by design.
Although at least one has a flag so that gcc doesn't warn, cppcheck has its
own warnings about this. Add specific inline suppressions for these rather
than a blanket suppression in the Makefile.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
I can't get this warning to trigger, even without the suppression, so
remove it. If it shows up again on some cppcheck version, we can replace
it with inline suppressions so it's clear where the issue lay.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
I can't get these warnings to trigger on the cppcheck versions I have, so
remove them. If we find in future we need to replace these, they should be
replaced with inline suppressions so its clear what's the section of code
at issue.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
I can't get this warning to trigger, so I think this suppression must be
out of date. Whether that's because we've changed our code to no longer
have the problem, or because cppcheck itself has been updated to remove a
false positive I don't know.
If we find that we do need a suppression like this for some cppcheck
version, we should replace it with an inline suppression so it's clear
what exactly is triggering the warning.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Recent versions of cppcheck give warnings if using a bitwise OR (|) where
some of the arguments are zero. We're triggering these warnings in our
generated seccomp.h header, because BPF_LD and BPF_W are zero-valued.
However putting these defines in makes the generate code clearer, even
though they could be left out without changing the values. So, add
cppcheck suppressions to the generated code.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
seccomp.sh generates seccomp.h, so if we change it, we should re-build
seccomp.h as well. Add this to the make dependencies so it happens.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Recent versions of cppcheck give a warning due to the NULL buffer passed
to recv() in tcp_sock_consume(). Since this apparently works, I assume
it's actually valid, but cppcheck doesn't know that recv() can take a NULL
buffer. So, use a suppression to get rid of the error.
Also add an unmatchedSuppression suppression since only some cppcheck
versions complain about this.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
TIMER_INTERVAL is the minimum of two separately defined intervals which
happen to have the same value at present. This results in an expression
which has the same value in both branches of a ternary operator, which
cppcheck warngs about. This is logically sound in this case, so suppress
the error (we appear to already have a similar suppression for clang-tidy).
Also add an unmatchedSuppression suppression, since only some cppcheck
versions complain about this instance.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
clang-tidy warns that in passing getenv("PATH") to strncpy() we could be
passing a NULL pointer. While it's unusual for PATH to be unset, it's not
impossible and this would indeed cause getenv() to return NULL.
Handle this case by never recognizing argv[2] as a qemu binary name if
PATH is not set. This is... no flakier than the detection of whether
it's a binary name already is.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Since bf95322f "conf: Make the argument to --pcap option mandatory" we
no longer call localtime() in pcap.c, so we no longer need the matching
cppcheck suppression.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
In a number of places in passt we use structures to represent over the wire
or in-file data with a fixed layout. After initialization we don't access
the fields individually and just write the structure as a whole to its
destination.
Unfortunately cppcheck doesn't cope with this pattern and thinks all the
structure members are unused. We already have suppressions for this in
pcap.c and dhcp.c However, it also appears in dhcp.c and netlink.c at
least. Since this is likely to be common, it seems wiser to just suppress
the error globally.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
We use a number of complex structures to format messages to send to
netlink. In some cases we add imaginary 'end' members not because they
actually mean something on the wire, but so that we can use offsetof() on
the member to determine the relevant size.
Adding extra things to the structures for this is kinda nasty. We can use
a different construct with offsetof and sizeof to avoid them. As a bonus
this removes some cppcheck warnings about unused struct members.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
strtok() is non-reentrant and old-fashioned, so cppcheck would complains
about its use in conf.c if it weren't suppressed. We're single threaded
and strtok() is convenient though, so it's not really worth reworking at
this time. Convert this to an inline suppression so it's adjacent to the
code its annotating.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
qrap.c uses several old-fashioned functions that cppcheck complains about.
Since it's headed for obselesence anyway, just suppress these rather than
attempting to modernize the code.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
We define our own ffsl() as a weak symbol, in case our C library doesn't
include it. On glibc systems which *do* include it, this causes a cppcheck
warning because unsurprisingly our version doesn't pick the same argument
names. Convert the suppression for this into an inline suppression.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Some versions of cppcheck could errneously report a NULL pointer deference
inside a sizeof(). This is now fixed in cppcheck upstream[0]. For systems
using an affected version, add a suppression to work around the bug. Also
add an unmatchedSuppression suppression so the suppression itself doesn't
cause a warning if you *do* have a fixed cppcheck.
[0] https://github.com/danmar/cppcheck/pull/4471
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Add the -Wextra -pedantic and -std=c99 flags when compiling the nsholder
test helper to get extra compiler checks, like we already use for the
main source code.
While we're there, fix some %d (signed) printf descriptors being used
for unsigned values (uid_t and gid_t). Pointed out by cppcheck.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
cppcheck points out that qrap's main shadows the global err() function with
a local. Rename it to rc to avoid the clash.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
The counter 'i' is used in a number of places in conf_ports(), but in one
of those we unnecessarily shadow it in an inner scope. We could re-use the
same 'i' every time, but each use is logically separate, so instead remove
the outer declaration and declare it locally in each of the clauses where
we need it.
While we're there change it from a signed to unsigned int, since it's used
to iterate over port numbers which are generally treated as unsigned.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Minor style improvement suggested by cppcheck.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
conf_runas() handles several of the different possible cases for the
--runas argument in a slightly odd order. Although it can parse both
numeric UIDs/GIDs and user/group names, it can't parse a numeric UID
combined with a group name or vice versa. That's not obviously useful, but
it's slightly surprising gap to have.
Rework the parsing to be more systematic: first split the option into
user and (optional) group parts, then separately parse each part as either
numeric or a name. As a bonus this removes some clang-tidy warnings.
While we're there also add cppcheck suppressions for getpwnam() and
getgrnam(). It complains about those because they're not reentrant.
passt is single threaded though, and is always likely to be during
this initialization code, even if we multithread later.
There were some existing suppressions for these in the cppcheck
invocation but they're no longer up to date. Replace them with inline
suppressions which, being next to the code, are more likely to stay
correct.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
dhcpv6.c contains a number of structures which represent actual DHCPv6
packets as they appear on the wire, which will break if the structures
don't have exactly the in-memory layout we expect.
Therefore, we should mark these structures as ((packed)). The contents of
them means this is unlikely to change the layout in practice - and since
it was working, presumably didn't on any arch we were testing on. However
it's not impossible for the compiler on some arch to insert unexpected
padding in one of these structures, so we should be explicit.
clang-tidy warned about this since we were using memcmp() to compare some
of these structures, which it thought might not have a unique
representation.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Stop ignoring the return codes from sigaction() and signal(). Unlikely to
happen in practice, but if it ever did it could lead to really hard to
debug problems. So, take clang-tidy's advice and check for errors here.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
clang-tidy isn't quite clever enough to figure out that getenv("SHELL")
will return the same thing both times here, which makes it conclude that
shell could be NULL, causing problems later.
It's a bit ugly that we call getenv() twice in any case, so rework this in
a way that clang-tidy can figure out shell won't be NULL.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
clang-tidy complains that we're not checking the result of vfprintf in
logfn(). There's not really anything we can do if this fails here, so just
suppress the error with a cast to void.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
conf_ports() parses ranges of ports for the -t, -u, -T and -U options.
The code is quite difficult to the follow, to the point that clang-tidy
and cppcheck disagree on whether one of the pointers can be NULL at some
points.
Rework the code with the use of two new helper functions:
* parse_port_range() operates a bit like strtoul(), but can parse a whole
port range specification (e.g. '80' or '1000-1015')
* next_chunk() does the necessary wrapping around strchr() to advance to
just after the next given delimiter, while cleanly handling if there
are no more delimiters
The new version is easier to follow, and also removes some cppcheck
warnings.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Debian and similar distros put target specific header files in
/usr/include/<arch-vendor-os>, rather than directly in /usr/include. Add
this directory to the includes for cppcheck so it can find them.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
We do some manipulation of the output of cc -v to get the target triple
for the platform, to locate headers for cppcheck. However, we can get
this more easily with cc -dumpmachine - and in fact we do so elsewhere in
the Makefile.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Adding the --quiet option to cppcheck makes the actual errors and warnings
easier to find.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
make cppcheck takes a long time, because it checks a large number of
different configurations. It's assembling this very large set of
configurations not because of conditionals in the passt code itself,
but from those in the system headers. By adding --config-exclude
directives to stop considering those configs, make cppcheck becomes
around 60x faster on my system.
Similarly, any problems that are found in the system headers are not our
problem, and so we can uniformly suppress them, rather than having specific
suppressions for particular problems in particular files (which might not
be correct for all different distro / version combinations either).
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This check complains about any identifier of less than 3 characters. For
locals and parameters this is often pointlessly verbose. Disable it.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
