The coccinellery repository provides many little semantic patches to fix common
problems in the code. The number of semantic patches in the coccinellery
repository is high and most of the semantic patches apply only for Linux, so it
doesn't make sense to run them on regular basis as the processing takes a lot of
time.
The list of issue found in BIND 9, by no means complete, includes:
- double assignment to a variable
- `continue` at the end of the loop
- double checks for `NULL`
- useless checks for `NULL` (cannot be `NULL`, because of earlier return)
- using `0` instead of `NULL`
- useless extra condition (`if (foo) return; if (!foo) { ...; }`)
- removing & in front of static functions passed as arguments
This commit was done by hand to add the RUNTIME_CHECK() around stray
dns_name_copy() calls with NULL as third argument. This covers the edge cases
that doesn't make sense to write a semantic patch since the usage pattern was
unique or almost unique.
This second commit uses second semantic patch to replace the calls to
dns_name_copy() with NULL as third argument where the result was stored in a
isc_result_t variable. As the dns_name_copy(..., NULL) cannot fail gracefully
when the third argument is NULL, it was just a bunch of dead code.
Couple of manual tweaks (removing dead labels and unused variables) were
manually applied on top of the semantic patch.
This commit add RUNTIME_CHECK() around all simple dns_name_copy() calls where
the third argument is NULL using the semantic patch from the previous commit.
Until now, the build process for BIND on Windows involved upgrading the
solution file to the version of Visual Studio used on the build host.
Unfortunately, the executable used for that (devenv.exe) is not part of
Visual Studio Build Tools and thus there is no clean way to make that
executable part of a Windows Server container.
Luckily, the solution upgrade process boils down to just adding XML tags
to Visual Studio project files and modifying certain XML attributes - in
files which we pregenerate anyway using win32utils/Configure. Thus,
extend win32utils/Configure with three new command line parameters that
enable it to mimic what "devenv.exe bind9.sln /upgrade" does. This
makes the devenv.exe build step redundant and thus facilitates building
BIND in Windows Server containers.
isc_event_allocate() calls isc_mem_get() to allocate the event structure. As
isc_mem_get() cannot fail softly (e.g. it never returns NULL), the
isc_event_allocate() cannot return NULL, hence we remove the (ret == NULL)
handling blocks using the semantic patch from the previous commit.
For some libc implementations, BUFSIZ is small enough (e.g. 1024 for
musl libc) to trigger compilation warnings about insufficient size of
certain buffers. Since the relevant buffers are used for printing DNS
names, increase their size to '(n + 1) * DNS_NAME_FORMATSIZE', where 'n'
is the number of DNS names which are printed to a given buffer. This
results in somewhat arbitrary, albeit nicely-aligned and large enough
buffer sizes.
Make sure all unit tests include headers in a similar order:
1. Three headers which must be included before <cmocka.h>.
2. System headers.
3. UNIT_TESTING definition, followed by the <cmocka.h> header.
4. libisc headers.
5. Headers from other BIND libraries.
6. Local headers.
Also make sure header file names are sorted alphabetically within each
block of #include directives.
All unit tests define the UNIT_TESTING macro, which causes <cmocka.h> to
replace malloc(), calloc(), realloc(), and free() with its own functions
tracking memory allocations. In order for this not to break
compilation, the system header declaring the prototypes for these
standard functions must be included before <cmocka.h>.
Normally, these prototypes are only present in <stdlib.h>, so we make
sure it is included before <cmocka.h>. However, musl libc also defines
the prototypes for calloc() and free() in <sched.h>, which is included
by <pthread.h>, which is included e.g. by <isc/mutex.h>. Thus, unit
tests including "dnstest.h" (which includes <isc/mem.h>, which includes
<isc/mutex.h>) after <cmocka.h> will not compile with musl libc as for
these programs, <sched.h> will be included after <cmocka.h>.
Always including <cmocka.h> after all other header files is not a
feasible solution as that causes the mock assertion macros defined in
<isc/util.h> to mangle the contents of <cmocka.h>, thus breaking
compilation. We cannot really use the __noreturn__ or analyzer_noreturn
attributes with cmocka assertion functions because they do return if the
tested condition is true. The problem is that what BIND unit tests do
is incompatible with Clang Static Analyzer's assumptions: since we use
cmocka, our custom assertion handlers are present in a shared library
(i.e. it is the cmocka library that checks the assertion condition, not
a macro in unit test code). Redefining cmocka's assertion macros in
<isc/util.h> is an ugly hack to overcome that problem - unfortunately,
this is the only way we can think of to make Clang Static Analyzer
properly process unit test code. Giving up on Clang Static Analyzer
being able to properly process unit test code is not a satisfactory
solution.
Undefining _GNU_SOURCE for unit test code could work around the problem
(musl libc's <sched.h> only defines the prototypes for calloc() and
free() when _GNU_SOURCE is defined), but doing that could introduce
discrepancies for unit tests including entire *.c files, so it is also
not a good solution.
All in all, including <sched.h> before <cmocka.h> for all affected unit
tests seems to be the most benign way of working around this musl libc
quirk. While quite an ugly solution, it achieves our goals here, which
are to keep the benefit of proper static analysis of unit test code and
to fix compilation against musl libc.
This commit changes the BIND cookie algorithms to match
draft-sury-toorop-dnsop-server-cookies-00. Namely, it changes the Client Cookie
algorithm to use SipHash 2-4, adds the new Server Cookie algorithm using SipHash
2-4, and changes the default for the Server Cookie algorithm to be siphash24.
Add siphash24 cookie algorithm, and make it keep legacy aes as
- "--with-geoip" is used to enable the legacy GeoIP library.
- "--with-geoip2" is used to enable the new GeoIP2 library
(libmaxminddb), and is on by default if the library is found.
- using both "--with-geoip" and "--with-geoip2" at the same time
is an error.
- an attempt is made to determine the default GeoIP2 database path at
compile time if pkg-config is able to report the module prefix. if
this fails, it will be necessary to set the path in named.conf with
geoip-directory
- Makefiles have been updated, and a stub lib/dns/geoip2.c has been
added for the eventual GeoIP2 search implementation.
- when processing authoritative queries for ./NS, set 'gluedb' so
that glue will be included in the response, regardless of how
'minimal-responses' has been configured.
The ax_check_openssl m4 macro used OPENSSL_INCLUDES. Rename the
subst variable to OPENSSL_CFLAGS and wrap AX_CHECK_OPENSSL() in
action-if-not-found part of PKG_CHECK_MODULE check for libcrypto.
The json-c have previously leaked into the global namespace leading
to forced -I<include_path> for every compilation unit using isc/xml.h
header. This MR fixes the usage making the caller object opaque.
The libxml2 have previously leaked into the global namespace leading
to forced -I<include_path> for every compilation unit using isc/xml.h
header. This MR fixes the usage making the caller object opaque.
We increase recursclients when we attach to recursion quota,
decrease when we detach. In some cases, when we hit soft
quota, we might attach to quota without increasing recursclients
gauge. We then decrease the gauge when we detach from quota,
and it causes the statistics to underflow.
Fix makes sure that we increase recursclients always when we
succesfully attach to recursion quota.
qname minimization, even in relaxed mode, can fail on
some very broken domains. In relaxed mode, instead of
asking for "foo.bar NS" ask for "_.foo.bar A" to either
get a delegation or NXDOMAIN. It will require more queries
than regular mode for proper NXDOMAINs.
in the "refactor tcpquota and pipeline refs" commit, the counting
of active interfaces was tightened in such a way that named could
fail to listen on an interface if there were more interfaces than
tcp-clients. when checking the quota to start accepting on an
interface, if the number of active clients was above zero, then
it was presumed that some other client was able to handle accepting
new connections. this, however, ignored the fact that the current client
could be included in that count, so if the quota was already exceeded
before all the interfaces were listening, some interfaces would never
listen.
we now check whether the current client has been marked active; if so,
then the number of active clients on the interface must be greater
than 1, not 0.
(cherry picked from commit 02365b87ea0b1ea5ea8b17376f6734c811c95e61)
(cherry picked from commit cae79e1bab677ed1c2ce3adc5d54163a78f0d30b)
- if the TCP quota has been exceeded but there are no clients listening
for new connections on the interface, we can now force attachment to the
quota using isc_quota_force(), instead of carrying on with the quota not
attached.
- the TCP client quota is now referenced via a reference-counted
'ns_tcpconn' object, one of which is created whenever a client begins
listening for new connections, and attached to by members of that
client's pipeline group. when the last reference to the tcpconn
object is detached, it is freed and the TCP quota slot is released.
- reduce code duplication by adding mark_tcp_active() function
- convert counters to stdatomic
(cherry picked from commit a8dd133d270873b736c1be9bf50ebaa074f5b38f)
(cherry picked from commit 4a8fc979c49104534cf6be5d81dc54da5b6836c9)
- ensure that tcpactive is cleaned up correctly when accept() fails.
- set 'client->tcpattached' when the client is attached to the tcpquota.
carry this value on to new clients sharing the same pipeline group.
don't call isc_quota_detach() on the tcpquota unless tcpattached is
set. this way clients that were allowed to accept TCP connections
despite being over quota (and therefore, were never attached to the
quota) will not inadvertently detach from it and mess up the
accounting.
- simplify the code for tcpquota disconnection by using a new function
tcpquota_disconnect().
- before deciding whether to reject a new connection due to quota
exhaustion, check to see whether there are at least two active
clients. previously, this was "at least one", but that could be
insufficient if there was one other client in READING state (waiting
for messages on an open connection) but none in READY (listening
for new connections).
- before deciding whether a TCP client object can to go inactive, we
must ensure there are enough other clients to maintain service
afterward -- both accepting new connections and reading/processing new
queries. A TCP client can't shut down unless at least one
client is accepting new connections and (in the case of pipelined
clients) at least one additional client is waiting to read.
(cherry picked from commit 427a2fb4d17bc04ca3262f58a9dcf5c93fc6d33e)
(cherry picked from commit 08968412726d680777de6e596c836c6be07819a1)
Track pipeline groups using a shared reference counter
instead of a linked list.
(cherry picked from commit 31f392db20207a1b05d6286c3c56f76c8d69e574)
(cherry picked from commit 2211120222b5f008a96145474b7f6749d4307028)
the TCP client quota could still be ineffective under some
circumstances. this change:
- improves quota accounting to ensure that TCP clients are
properly limited, while still guaranteeing that at least one client
is always available to serve TCP connections on each interface.
- uses more descriptive names and removes one (ntcptarget) that
was no longer needed
- adds comments
(cherry picked from commit 9e74969f85329fe26df2fad390468715215e2edd)
(cherry picked from commit d7e84cee0bd7957a0707b86d47c29de4b798d350)
tcp-clients settings could be exceeded in some cases by
creating more and more active TCP clients that are over
the set quota limit, which in the end could lead to a
DoS attack by e.g. exhaustion of file descriptors.
If TCP client we're closing went over the quota (so it's
not attached to a quota) mark it as mortal - so that it
will be destroyed and not set up to listen for new
connections - unless it's the last client for a specific
interface.
(cherry picked from commit eafcff07c25bdbe038ae1e4b6660602a080b9395)
(cherry picked from commit 9e7617cc84f465769be1a3f426f30cd516220902)
- Always set is_zonep in query_getdb; previously it was only set if
result was ISC_R_SUCCESS or ISC_R_NOTFOUND.
- Don't reset is_zone for redirect.
- Style cleanup.
(cherry picked from commit a85cc641d7a4c66cbde03cc4e31edc038a24df46)
(cherry picked from commit 486a201149ab7523e3b3089fc84f20d7f1a07a24)
