We handle SIGQUIT and SIGTERM calling exit(), which is usually
implemented with the exit_group() system call.

If we don't allow exit_group(), we'll get a SIGSYS while handling
SIGQUIT and SIGTERM, which means a misleading non-zero exit code.

Reported-by: Wenli Quan <wquan@redhat.com>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2101990
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

If the tests are interrupted at the right point a passt.pid file can be
left over.  Clean it up with "make clean" and add it to .gitignore so it
doesn't get accidentally committed.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

Two places in passt need to read files line by line (one parsing
resolv.conf, the other parsing /proc/net/*.  They can't use fgets()
because in glibc that can allocate memory.  Instead they use an
implementation line_read() in util.c.  This has some problems:

 * It has two completely separate modes of operation, one buffering
   and one not, the relation between these and how they're activated
   is subtle and confusing
 * At least in non-buffered mode, it will mishandle an empty line,
   folding them onto the start of the next non-empty line
 * In non-buffered mode it will use lseek() which prevents using this
   on non-regular files (we don't need that at present, but it's a
   surprising limitation)
 * It has a lot of difficult to read pointer mangling

Add a new cleaner implementation of allocation-free line-by-line
reading in lineread.c.  This one always buffers, using a state
structure to keep track of what we need.  This is larger than I'd
like, but it turns out handling all the edge cases of line-by-line
reading in C is surprisingly hard.

This just adds the code, subsequent patches will change the existing
users of line_read() to the new implementation.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

In order to probe availability of certain features the Makefile test
compiles a handful of tiny snippets, feeding those in from stdin.  However
in one case - the one for -fstack-protector - it forgets to redirect the
output to stdout, meaning it creates a stray '-.s' file when make is
invoked (even make clean).

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

The use of rm commands in the clean and uninstall targets adds an explicit
leading - to ignore errors.  However the built-in RM variable in make is
actually "rm -f" which already ignores errors, so the - isn't neccessary.

Also replace ${RM} with $(RM) which is the more conventional form in
Makefiles.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

pasta, pasta.avx2 and pasta.1 are all generated as a link to the
corresponding passt file.  We can consolidate the 3 rules for these targets
into a single pattern rule.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

There are several places which explicitly list the various generated
binaries, even though a $(BIN) variable already lists them.  There are
several more places that list all the manpage files, introduce a
$(MANPAGES) variable to remove that repetition as well.

Tweak the generation of pasta.1 as a link to passt.1 so it's not just made
as a side effect of the pasta target.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
[sbrivio: add passt.1 and qrap.1 to guest files for distro tests]
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

The passt/pasta Makefile makes fairly heavy use of GNU make's $(wildcard)
function to locate the sources and headers to build.  Using wildcards for
the things to compile is usually a bad idea though: if somehow you end up
with a .c or .h file in your tree you didn't expect it can misbuild in an
exceedingly confusing way.  In particular this can sometimes happen if
switching between releases / branches where files have been added or
removed without 100% cleaning the tree.

It also makes life a bit complicated if building multiple different
binaries in the same tree: we already have some rather awkward
$(filter-out) constructions to avoid including qrap.c in the passt build.

Replace use of $(wildcard) with the more idiomatic approach of defining
variables listing all the relevant source files then using that throughout.
In the rule for seccomp.h there was also a bare "*.c" which caused make to
always rebuild that target.  Fix that as well.

Similarly, seccomp.sh uses a wildcard to locate the sources, which is
unwise for the same reasons.  Make it take the sources to examine on the
command line instead, and have the Makefile pass them in from the same
variables.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

New from Cppcheck 2.8: all the fields of struct msg that are not
directly manipulated are now reported as unused, which is kind of
correct as those fields are used as a blob "copied" from request
to response and not as separate fields.

However, keeping the message composition explicit is probably
desirable, and adding inline suppressions makes the whole thing
rather unreadable, so just suppress unusedStructMember warnings for
dhcp.c, while also adding a suppression for unmatched suppressions
to keep earlier versions of Cppcheck happy.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>