Unify the header guard style and replace the inconsistent include guards
with #pragma once.
The #pragma once is widely and very well supported in all compilers that
BIND 9 supports, and #pragma once was already in use in several new or
refactored headers.
Using simpler method will also allow us to automate header guard checks
as this is simpler to programatically check.
For reference, here are the reasons for the change taken from
Wikipedia[1]:
> In the C and C++ programming languages, #pragma once is a non-standard
> but widely supported preprocessor directive designed to cause the
> current source file to be included only once in a single compilation.
>
> Thus, #pragma once serves the same purpose as include guards, but with
> several advantages, including: less code, avoidance of name clashes,
> and sometimes improvement in compilation speed. On the other hand,
> #pragma once is not necessarily available in all compilers and its
> implementation is tricky and might not always be reliable.
1. https://en.wikipedia.org/wiki/Pragma_once
libidn2 defaults to UseSTD3ASCIIRules=false. That allows arbitrary ASCII
characters to show up in the toASCII output, including space and
underscore. Enable IDN2_USE_STD3_ASCII_RULES to the libidn2 conversion
to disallow additional characters from the conversion (see Validity
Criteria[1]).
Remove the dynamic registration of result codes. Convert isc_result_t
from unsigned + #defines into 32-bit enum type in grand unified
<isc/result.h> header. Keep the existing values of the result codes
even at the expense of the description and identifier tables being
unnecessary large.
Additionally, add couple of:
switch (result) {
[...]
default:
break;
}
statements where compiler now complains about missing enum values in the
switch statement.
This commit makes dig fail with error in case a zone transfer is
attempted over a connections where ALPN was not negotiated. All other
request types will work fine.
The native PKCS#11 support has been removed in favour of better
maintained, more performance and easier to use OpenSSL PKCS#11 engine
from the OpenSC project.
This commit replaces ad-hoc code for DoH connect URI construction with
isc_nm_http_makeuri(), making it handle IPv6 adresses properly (among
other things).
Current mempools are kind of hybrid structures - they serve two
purposes:
1. mempool with a lock is basically static sized allocator with
pre-allocated free items
2. mempool without a lock is a doubly-linked list of preallocated items
The first kind of usage could be easily replaced with jemalloc small
sized arena objects and thread-local caches.
The second usage not-so-much and we need to keep this (in
libdns:message.c) for performance reasons.
This commit adds two new autoconf options `--enable-doh` (enabled by
default) and `--with-libnghttp2` (mandatory when DoH is enabled).
When DoH support is disabled the library is not linked-in and support
for http(s) protocol is disabled in the netmgr, named and dig.
The isc/platform.h header was left empty which things either already
moved to config.h or to appropriate headers. This is just the final
cleanup commit.
The last remaining defines needed for platforms without NAME_MAX and
PATH_MAX (I'm looking at you, GNU Hurd) were moved to isc/dir.h where
it's prevalently used.
The Makefile.tests was modifying global AM_CFLAGS and LDADD and could
accidentally pull /usr/include to be listed before the internal
libraries, which is known to cause problems if the headers from the
previous version of BIND 9 has been installed on the build machine.
Previously, we would set the locale on a global level and that could
possibly lead to different behaviour in underlying functions. In this
commit, we change to code to use the system locale only when calling the
libidn2 functions and reset the locale back to "POSIX" when exiting the
libidn2 code.
The Windows support has been completely removed from the source tree
and BIND 9 now no longer supports native compilation on Windows.
We might consider reviewing mingw-w64 port if contributed by external
party, but no development efforts will be put into making BIND 9 compile
and run on Windows again.
The isc_nmiface_t type was holding just a single isc_sockaddr_t,
so we got rid of the datatype and use plain isc_sockaddr_t in place
where isc_nmiface_t was used before. This means less type-casting and
shorter path to access isc_sockaddr_t members.
At the same time, instead of keeping the reference to the isc_sockaddr_t
that was passed to us when we start listening, we will keep a local
copy. This prevents the data race on destruction of the ns_interface_t
objects where pending nmsockets could reference the sockaddr of already
destroyed ns_interface_t object.
dns_name_copy() has been replaced nearly everywhere with
dns_name_copynf(). this commit changes the last two uses of
the original function. afterward, we can remove the old
dns_name_copy() implementation, and replace it with _copynf().
dns_message_gettempname() now returns a pointer to an initialized
name associated with a dns_fixedname_t object. it is no longer
necessary to allocate a buffer for temporary names associated with
the message object.
This workarounds couple of races where the current_lookup would be
already detached during shutting down the dig, but still processing the
pending reads.
The start_udp() function didn't properly attach to the query and thus
a callback with ISC_R_CANCELED would end with wrong accounting on the
query object.
Usually, this doesn't happen because underlying libuv API
uv_udp_connect() is synchronous, but isc_nm_udpconnect() could return
ISC_R_CANCELED in case it's called while the netmgr is shutting down.
Previously, netmgr, taskmgr, timermgr and socketmgr all had their own
isc_<*>mgr_create() and isc_<*>mgr_destroy() functions. The new
isc_managers_create() and isc_managers_destroy() fold all four into a
single function and makes sure the objects are created and destroy in
correct order.
Especially now, when taskmgr runs on top of netmgr, the correct order is
important and when the code was duplicated at many places it's easy to
make mistake.
The former isc_<*>mgr_create() and isc_<*>mgr_destroy() functions were
made private and a single call to isc_managers_create() and
isc_managers_destroy() is required at the program startup / shutdown.
_query_detach function was incorrectly unliking the query object from
the lookup->q query list, this made it impossible to follow a query
lookup failure with the next one in the list (possibly using a separate
resolver), as the link to the next query in the list was dissolved.
Fix by unliking the node only when the query object is about to be
destroyed, i.e. there is no more references to the object.
This commit changes the taskmgr to run the individual tasks on the
netmgr internal workers. While an effort has been put into keeping the
taskmgr interface intact, couple of changes have been made:
* The taskmgr has no concept of universal privileged mode - rather the
tasks are either privileged or unprivileged (normal). The privileged
tasks are run as a first thing when the netmgr is unpaused. There
are now four different queues in in the netmgr:
1. priority queue - netievent on the priority queue are run even when
the taskmgr enter exclusive mode and netmgr is paused. This is
needed to properly start listening on the interfaces, free
resources and resume.
2. privileged task queue - only privileged tasks are queued here and
this is the first queue that gets processed when network manager
is unpaused using isc_nm_resume(). All netmgr workers need to
clean the privileged task queue before they all proceed normal
operation. Both task queues are processed when the workers are
finished.
3. task queue - only (traditional) task are scheduled here and this
queue along with privileged task queues are process when the
netmgr workers are finishing. This is needed to process the task
shutdown events.
4. normal queue - this is the queue with netmgr events, e.g. reading,
sending, callbacks and pretty much everything is processed here.
* The isc_taskmgr_create() now requires initialized netmgr (isc_nm_t)
object.
* The isc_nm_destroy() function now waits for indefinite time, but it
will print out the active objects when in tracing mode
(-DNETMGR_TRACE=1 and -DNETMGR_TRACE_VERBOSE=1), the netmgr has been
made a little bit more asynchronous and it might take longer time to
shutdown all the active networking connections.
* Previously, the isc_nm_stoplistening() was a synchronous operation.
This has been changed and the isc_nm_stoplistening() just schedules
the child sockets to stop listening and exits. This was needed to
prevent a deadlock as the the (traditional) tasks are now executed on
the netmgr threads.
* The socket selection logic in isc__nm_udp_send() was flawed, but
fortunatelly, it was broken, so we never hit the problem where we
created uvreq_t on a socket from nmhandle_t, but then a different
socket could be picked up and then we were trying to run the send
callback on a socket that had different threadid than currently
running.
dig previously ran isc_nm_udpconnect() three times before giving
up, to work around a freebsd bug that caused connect() to return
a spurious transient EADDRINUSE. this commit moves the retry code
into the network manager itself, so that isc_nm_udpconnect() no
longer needs to return a result code.
Before this commit, a premature EOF (connection closed) on tcp queries
was causing dig to automatically attempt to send the query again, even
if +tries=1 or +retries=0 was provided on command line.
This commit fix the problem by taking into account the no. of retries
specified by the user when processing a premature EOF on tcp
connections.
The TIME_NOW macro calls isc_time_now which uses CLOCK_REALTIME_COARSE
for getting the current time. This is perfectly fine for millisecond,
however when the user request microsecond resolutiuon, they are going
to get very inaccurate results. This is especially true on a server
class machine where the clock ticks may be set to 100HZ.
This changes dig to use the new TIME_NOW_HIRES macro that uses the
CLOCK_MONOTONIC_RAW that is more expensive, but gets the *actual*
current time rather than the at the last kernel time tick.
On 24-core machine, the tests would crash because we would run out of
the hazard pointers. We now adjust the number of hazard pointers to be
in the <128,256> interval based on the number of available cores.
Note: This is just a band-aid and needs a proper fix.
The <isc/readline.h> header provided a compatibility shim to use when
other non-GNU readline libraries are in use. The two places where
readline library is being used is nslookup and nsupdate, so the header
file has been moved to bin/dig directory and it's directly included from
bin/nsupdate.
This also conceals any readline headers exposed from the libisc headers.
* Following the example set in 634bdfb16d, the tlsdns netmgr
module now uses libuv and SSL primitives directly, rather than
opening a TLS socket which opens a TCP socket, as the previous
model was difficult to debug. Closes#2335.
* Remove the netmgr tls layer (we will have to re-add it for DoH)
* Add isc_tls API to wrap the OpenSSL SSL_CTX object into libisc
library; move the OpenSSL initialization/deinitialization from dstapi
needed for OpenSSL 1.0.x to the isc_tls_{initialize,destroy}()
* Add couple of new shims needed for OpenSSL 1.0.x
* When LibreSSL is used, require at least version 2.7.0 that
has the best OpenSSL 1.1.x compatibility and auto init/deinit
* Enforce OpenSSL 1.1.x usage on Windows
* Added a TLSDNS unit test and implemented a simple TLSDNS echo
server and client.
This is a part of the works that intends to make the netmgr stable,
testable, maintainable and tested. It contains a numerous changes to
the netmgr code and unfortunately, it was not possible to split this
into smaller chunks as the work here needs to be committed as a complete
works.
NOTE: There's a quite a lot of duplicated code between udp.c, tcp.c and
tcpdns.c and it should be a subject to refactoring in the future.
The changes that are included in this commit are listed here
(extensively, but not exclusively):
* The netmgr_test unit test was split into individual tests (udp_test,
tcp_test, tcpdns_test and newly added tcp_quota_test)
* The udp_test and tcp_test has been extended to allow programatic
failures from the libuv API. Unfortunately, we can't use cmocka
mock() and will_return(), so we emulate the behaviour with #define and
including the netmgr/{udp,tcp}.c source file directly.
* The netievents that we put on the nm queue have variable number of
members, out of these the isc_nmsocket_t and isc_nmhandle_t always
needs to be attached before enqueueing the netievent_<foo> and
detached after we have called the isc_nm_async_<foo> to ensure that
the socket (handle) doesn't disappear between scheduling the event and
actually executing the event.
* Cancelling the in-flight TCP connection using libuv requires to call
uv_close() on the original uv_tcp_t handle which just breaks too many
assumptions we have in the netmgr code. Instead of using uv_timer for
TCP connection timeouts, we use platform specific socket option.
* Fix the synchronization between {nm,async}_{listentcp,tcpconnect}
When isc_nm_listentcp() or isc_nm_tcpconnect() is called it was
waiting for socket to either end up with error (that path was fine) or
to be listening or connected using condition variable and mutex.
Several things could happen:
0. everything is ok
1. the waiting thread would miss the SIGNAL() - because the enqueued
event would be processed faster than we could start WAIT()ing.
In case the operation would end up with error, it would be ok, as
the error variable would be unchanged.
2. the waiting thread miss the sock->{connected,listening} = `true`
would be set to `false` in the tcp_{listen,connect}close_cb() as
the connection would be so short lived that the socket would be
closed before we could even start WAIT()ing
* The tcpdns has been converted to using libuv directly. Previously,
the tcpdns protocol used tcp protocol from netmgr, this proved to be
very complicated to understand, fix and make changes to. The new
tcpdns protocol is modeled in a similar way how tcp netmgr protocol.
Closes: #2194, #2283, #2318, #2266, #2034, #1920
* The tcp and tcpdns is now not using isc_uv_import/isc_uv_export to
pass accepted TCP sockets between netthreads, but instead (similar to
UDP) uses per netthread uv_loop listener. This greatly reduces the
complexity as the socket is always run in the associated nm and uv
loops, and we are also not touching the libuv internals.
There's an unfortunate side effect though, the new code requires
support for load-balanced sockets from the operating system for both
UDP and TCP (see #2137). If the operating system doesn't support the
load balanced sockets (either SO_REUSEPORT on Linux or SO_REUSEPORT_LB
on FreeBSD 12+), the number of netthreads is limited to 1.
* The netmgr has now two debugging #ifdefs:
1. Already existing NETMGR_TRACE prints any dangling nmsockets and
nmhandles before triggering assertion failure. This options would
reduce performance when enabled, but in theory, it could be enabled
on low-performance systems.
2. New NETMGR_TRACE_VERBOSE option has been added that enables
extensive netmgr logging that allows the software engineer to
precisely track any attach/detach operations on the nmsockets and
nmhandles. This is not suitable for any kind of production
machine, only for debugging.
* The tlsdns netmgr protocol has been split from the tcpdns and it still
uses the old method of stacking the netmgr boxes on top of each other.
We will have to refactor the tlsdns netmgr protocol to use the same
approach - build the stack using only libuv and openssl.
* Limit but not assert the tcp buffer size in tcp_alloc_cb
Closes: #2061
This commit extends the perl Configure script to also check for libssl
in addition to libcrypto and change the vcxproj source files to link
with both libcrypto and libssl.
The recv_done() callback had many exit paths with different conditions,
and every path had it's own set of destructors. The refactored code now
has unified exit path with descriptive goto labels matching the intent:
- cancel_lookup
- next_lookup
- detach_query
- keep_query
The only exception to the rule is check_for_more_data() path, where the
part of the query gets reused, so the query->readhandle and query gets
detached on it's own, and by going to the keep_query, we are just
skipping calling the destructors again.
FreeBSD sometimes returns spurious errors in UDP connect() attempts,
so we try a few times before giving up. However, each failed attempt
triggers a call to udp_ready() in dighost.c, and that was causing
the query object to be detached prematurely.
Sometimes, the dig_lookup_t could be destroyed before the final
send_done() callback was be called, leading to dereferencing an
already freed dig_lookup_t object. By making the dig_lookup_t
reference counted, we are ensuring that it won't be freed until
the last reference (from dig_query_t .lookup) is released.
because dig now uses the netmgr, printing of response messages
happens in a different thread than setup. the IDN output filtering
procedure, which set using dns_name_settotextfilter(), is stored as
thread-local data, and so if it's set during setup, it won't be
accessible when printing. we now set it immediately before printing,
in the same thread, and clear it immedately afterward.
The network manager does not support returning UDP datagrams to
clients from unexpected sources; it is therefore not possible for
dig to accept them. The "+[no]unexpected" option has therefore
been removed from the dig command and its documentation.
The dns_message_create() function cannot soft fail (as all memory
allocations either succeed or cause abort), so we change the function to
return void and cleanup the calls.
This commit updates and simplifies the checks for the readline support
in nslookup and nsupdate:
* Change the autoconf checks to pkg-config only, all supported
libraries have accompanying .pc files now.
* Add editline support in addition to libedit and GNU readline
* Add isc/readline.h shim header that defines dummy readline()
function when no readline library is available
The ARM and the manpages have been converted into Sphinx documentation
format.
Sphinx uses reStructuredText as its markup language, and many of its
strengths come from the power and straightforwardness of
reStructuredText and its parsing and translating suite, the Docutils.
The rewrite of BIND 9 build system is a large work and cannot be reasonable
split into separate merge requests. Addition of the automake has a positive
effect on the readability and maintainability of the build system as it is more
declarative, it allows conditional and we are able to drop all of the custom
make code that BIND 9 developed over the years to overcome the deficiencies of
autoconf + custom Makefile.in files.
This squashed commit contains following changes:
- conversion (or rather fresh rewrite) of all Makefile.in files to Makefile.am
by using automake
- the libtool is now properly integrated with automake (the way we used it
was rather hackish as the only official way how to use libtool is via
automake
- the dynamic module loading was rewritten from a custom patchwork to libtool's
libltdl (which includes the patchwork to support module loading on different
systems internally)
- conversion of the unit test executor from kyua to automake parallel driver
- conversion of the system test executor from custom make/shell to automake
parallel driver
- The GSSAPI has been refactored, the custom SPNEGO on the basis that
all major KRB5/GSSAPI (mit-krb5, heimdal and Windows) implementations
support SPNEGO mechanism.
- The various defunct tests from bin/tests have been removed:
bin/tests/optional and bin/tests/pkcs11
- The text files generated from the MD files have been removed, the
MarkDown has been designed to be readable by both humans and computers
- The xsl header is now generated by a simple sed command instead of
perl helper
- The <irs/platform.h> header has been removed
- cleanups of configure.ac script to make it more simpler, addition of multiple
macros (there's still work to be done though)
- the tarball can now be prepared with `make dist`
- the system tests are partially able to run in oot build
Here's a list of unfinished work that needs to be completed in subsequent merge
requests:
- `make distcheck` doesn't yet work (because of system tests oot run is not yet
finished)
- documentation is not yet built, there's a different merge request with docbook
to sphinx-build rst conversion that needs to be rebased and adapted on top of
the automake
- msvc build is non functional yet and we need to decide whether we will just
cross-compile bind9 using mingw-w64 or fix the msvc build
- contributed dlz modules are not included neither in the autoconf nor automake
All our MSVS Project files share the same intermediate directory. We
know that this doesn't cause any problems, so we can just disable the
detection in the project files.
Example of the warning:
warning MSB8028: The intermediate directory (.\Release\) contains files shared from another project (dnssectool.vcxproj). This can lead to incorrect clean and rebuild behavior.
Our vcxproj files set the WarningLevel to Level3, which is too verbose
for a code that needs to be portable. That basically leads to ignoring
all the errors that MSVC produces. This commits downgrades the
WarningLevel to Level1 and enables treating warnings as errors for
Release builds. For the Debug builds the WarningLevel got upgraded to
Level4, and treating warnings as errors is explicitly disabled.
We should eventually make the code clean of all MSVC warnings, but it's
a long way to go for Level4, so it's more reasonable to start at Level1.
For reference[1], these are the warning levels as described by MSVC
documentation:
* /W0 suppresses all warnings. It's equivalent to /w.
* /W1 displays level 1 (severe) warnings. /W1 is the default setting
in the command-line compiler.
* /W2 displays level 1 and level 2 (significant) warnings.
* /W3 displays level 1, level 2, and level 3 (production quality)
warnings. /W3 is the default setting in the IDE.
* /W4 displays level 1, level 2, and level 3 warnings, and all level 4
(informational) warnings that aren't off by default. We recommend
that you use this option to provide lint-like warnings. For a new
project, it may be best to use /W4 in all compilations. This option
helps ensure the fewest possible hard-to-find code defects.
* /Wall displays all warnings displayed by /W4 and all other warnings
that /W4 doesn't include — for example, warnings that are off by
default.
* /WX treats all compiler warnings as errors. For a new project, it
may be best to use /WX in all compilations; resolving all warnings
ensures the fewest possible hard-to-find code defects.
1. https://docs.microsoft.com/en-us/cpp/build/reference/compiler-option-warning-level?view=vs-2019
The isc_mem API now crashes on memory allocation failure, and this is
the next commit in series to cleanup the code that could fail before,
but cannot fail now, e.g. isc_result_t return type has been changed to
void for the isc_log API functions that could only return ISC_R_SUCCESS.
On Windows, C11 localtime_r() and gmtime_r() functions are not
available. While localtime() and gmtime() functions are already thread
safe because they use Thread Local Storage, it's quite ugly to #ifdef
around every localtime_r() and gmtime_r() usage to make the usage also
thread-safe on POSIX platforms.
The commit adds wrappers around Windows localtime_s() and gmtime_s()
functions.
NOTE: The implementation of localtime_s and gmtime_s in Microsoft CRT
are incompatible with the C standard since it has reversed parameter
order and errno_t return type.
When --with-zlib is passed to ./configure (or when the latter
autodetects zlib's presence), libisc uses certain zlib functions and
thus libisc's users should be linked against zlib in that case. Adjust
Makefile variables appropriately to prevent shared build failures caused
by underlinking.
this corrects some style glitches such as:
```
long_function_call(arg, arg2, arg3, arg4, arg5, "str"
"ing");
```
...by adjusting the penalties for breaking strings and call
parameter lists.
The isc_buffer_allocate() function now cannot fail with ISC_R_MEMORY.
This commit removes all the checks on the return code using the semantic
patch from previous commit, as isc_buffer_allocate() now returns void.
The isc_mempool_create() function now cannot fail with ISC_R_MEMORY.
This commit removes all the checks on the return code using the semantic
patch from previous commit, as isc_mempool_create() now returns void.
Previously, the dns_name API used isc_thread_key API for TLS, which is
fairly complicated and requires initialization of memory contexts, etc.
This part of code was refactored to use a ISC_THREAD_LOCAL pointer which
greatly simplifies the whole code related to storing TLS variables.
The indentation for dumping the master zone was driven by two
global variables dns_master_indent and dns_master_indentstr. In
threaded mode, this becomes prone to data access races, so this commit
converts the global variables into a local per-context tuple that
consist of count and string.
When a task manager is created, we can now specify an `isc_nm`
object to associate with it; thereafter when the task manager is
placed into exclusive mode, the network manager will be paused.
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 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.
It is possible dig used ACE encoded name in locale, which does not
support converting it to unicode. Instead of fatal error, fallback to
ACE name on output.
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.
- "--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.
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.
dig retries a TCP query when a server closes the connection prematurely.
However, dig's exit code remains unaffected even if the second attempt
to get a response also fails with the same error for the same lookup,
which should not be the case. Ensure the exit code is updated
appropriately when a retry triggered by a TCP EOF condition fails.
When a query times out after a socket is created and associated with a
given dig_query_t structure, calling isc_socket_cancel() causes
connect_done() to be run, which in turn takes care of all necessary
cleanups. However, certain errors (e.g. get_address() returning
ISC_R_FAMILYNOSUPPORT) may prevent a TCP socket from being created in
the first place. Since force_timeout() may be used in code handling
such errors, connect_timeout() needs to properly clean up a TCP query
which is not associated with any socket. Call clear_query() from
connect_timeout() after attempting to send a TCP query to the next
available server if the timed out query does not have a socket
associated with it, in order to prevent dig from hanging indefinitely
due to the dig_query_t structure not being detached from its parent
dig_lookup_t structure.
When a query times out and another server is available for querying
within the same lookup, the timeout handler - connect_timeout() - is
responsible for sending the query to the next server. Extract the
relevant part of connect_timeout() to a separate function in order to
improve code readability.
Before commit c2ec022f57, using the "-b"
command line switch for dig did not disable use of the other address
family than the one to which the address supplied to that option
belonged to. Thus, bind9_getaddresses() could e.g. prepare an
isc_sockaddr_t structure for an IPv6 address when an IPv4 address has
been passed to the "-b" command line option. To avoid attempting the
impossible (e.g. querying an IPv6 address from a socket bound to an IPv4
address), a certain code block in send_tcp_connect() checked whether the
address family of the server to be queried was the same as the address
family of the socket set up for sending that query; if there was a
mismatch, that particular server address was skipped.
Commit c2ec022f57 made
bind9_getaddresses() fail upon an address family mismatch between the
address the hostname passed to it resolved to and the address supplied
to the "-b" command line option. Such failures were fatal to dig back
then.
Commit 7f65860391 made
bind9_getaddresses() failures non-fatal, but also ensured that a
get_address() failure in send_tcp_connect() still causes the given query
address to be skipped (and also made such failures trigger an early
return from send_tcp_connect()).
Summing up, the code block handling address family mismatches in
send_tcp_connect() has been redundant since commit
c2ec022f57. Remove it.
In BIND 9.11 and earlier, dig and similar tools used liblwres for
parsing /etc/resolv.conf. After getting a list of servers from
liblwres, a tool would check the address family of each server found and
reject those unusable. When the resulting list of usable servers was
empty, localhost addresses were queried as a fallback.
When liblwres was removed in BIND 9.12, dig and similar tools were
updated to parse /etc/resolv.conf using libirs instead. As part of that
process, the localhost fallback was removed from bin/dig/dighost.c since
the localhost fallback built into libirs was deemed to be sufficient.
However, libirs only falls back to localhost if it does not find any
name servers at all; if it does find any valid nameserver entry in
/etc/resolv.conf, it just returns it to the caller because it is
oblivious to whether the caller supports IPv4 and/or IPv6 or not. The
code in bin/dig/dighost.c subsequently filters the returned list of
servers in get_server_list() according to the requested address family
restrictions. This may result in none of the addresses returned by
libirs being usable, in which case a tool will attempt to work with an
empty server list, causing a hang and subsequently a crash upon user
interruption.
Restore the localhost fallback in bin/dig/dighost.c to prevent the
aforementioned hangs and crashes and ensure recent BIND versions behave
identically to the older ones in the circumstances described above.
If a tool using the routines defined in bin/dig/dighost.c is sent an
interruption signal around the time a connection timeout is scheduled to
fire, connect_timeout() may be executed after destroy_libs() detaches
from the global task (setting 'global_task' to NULL), which results in a
crash upon a UDP retry due to bringup_timer() attempting to create a
timer with 'task' set to NULL. Fix by preventing connect_timeout() from
attempting a retry when shutdown is in progress.
While implementing the new unit testing framework cmocka, it was found that the
BIND 9 code doesn't compile when assertions are disabled or replaced with any
function (such as mock_assert() from cmocka unit testing framework) that's not
directly recognized as assertion by the compiler.
This made the compiler to complain about blocks of code that was recognized as
unreachable before, but now it isn't.
The changes in this commit include:
* assigns default values to couple of local variables,
* moves some return statements around INSIST assertions,
* adds __builtin_unreachable(); annotations after some INSIST assertions,
* fixes one broken assertion (= instead of ==)
Refactor diagnostic tools code to no longer use:
- isc_socket_recvv()
- isc_socket_sendtov2()
- isc_socket_sendv()
as these functions will be removed shortly.
Manual page of host contained instructions to disable IDN processing
when it was built with libidn2. When refactoring IDN support however,
support for disabling IDN in host and nslookup was lost. Use also
environment variable and document it for nslookup, host and dig.
The "exitcode" variable is set to 9 if a TCP connection fails, but is
not reset to 0 if a subsequent TCP connection succeeds. This causes dig
to return a non-zero exit code if it succeeds in getting a TCP response
after a retry. Fix by resetting "exitcode" to 0 if connect_done()
receives an event with the "result" field set to ISC_R_SUCCESS.
Make will choose modified manual from build directory or original from source
directory automagically. Take advantage of install tool feature.
Install all files in single command instead of iterating on each of them.
While idn2_to_unicode_8zlz() takes a 'flags' argument, it is ignored and
thus cannot be used to perform IDN checks on the output string.
The bug in libidn2 versions before 2.0.5 was not that a call to
idn2_to_unicode_8zlz() with certain flags set did not cause IDN checks
to be performed. The bug was that idn2_to_unicode_8zlz() did not check
whether a conversion can be performed between UTF-8 and the current
locale's character encoding. In other words, with libidn2 version
2.0.5+, if the current locale's character encoding is ASCII, then
idn2_to_unicode_8zlz() will fail when it is passed any Punycode string
which decodes to a non-ASCII string, even if it is a valid IDNA2008
name.
Rework idn_ace_to_locale() so that invalid IDNA2008 names are properly
and consistently detected for all libidn2 versions and locales.
Update the "idna" system test accordingly. Add checks for processing a
server response containing Punycode which decodes to an invalid IDNA2008
name. Fix invalid subtest description.
Since idn_output_filter() no longer uses its 'absolute' argument and no
other callback is used with dns_name_settotextfilter(), remove the
'absolute' argument from the dns_name_totextfilter_t prototype.
output_filter() does not need to dot-terminate its input name because
libidn2 properly handles both dot-terminated and non-dot-terminated
names. libidn2 also does not implicitly dot-terminate names passed to
it, so parts of output_filter() handling dot termination can simply be
removed.
Fix a logical condition to make sure 'src' can fit the terminating NULL
byte. Replace the MAXDLEN macro with the MXNAME macro used in the rest
of dig source code. Tweak comments and variable names.
Rename output_filter() to idn_output_filter() so that it can be easily
associated with IDN and other idn_*() functions.
idn_ace_to_locale() may return a string longer than MAXDLEN because it
is using the current locale's character encoding. Rather then imposing
an arbitrary limit on the length of the string that function can return,
make it pass the string prepared by libidn2 back to the caller verbatim,
making the latter responsible for freeing that string. In conjunction
with the fact that libidn2 errors are considered fatal, this makes
returning an isc_result_t from idn_ace_to_locale() unnecessary.
Do not process success cases in conditional branches for improved
consistency with the rest of BIND source code. Add a comment explaining
the purpose of idn_ace_to_locale(). Rename that function's parameters
to match common BIND naming pattern.
idn_locale_to_ace() is a static function which is always used with a
buffer of size MXNAME, i.e. one that can fit any valid domain name.
Since libidn2 detects invalid domain names and libidn2 errors are
considered fatal, remove size checks from idn_locale_to_ace(). This
makes returning an isc_result_t from it unnecessary.
Do not process success cases in conditional branches for improved
consistency with the rest of BIND source code. Add a comment explaining
the purpose of idn_locale_to_ace(). Rename that function's parameters
to match common BIND naming pattern.
Certain characters, like symbols, are allowed by IDNA2003, but not by
IDNA2008. Make dig reject such symbols when IDN input processing is
enabled to ensure BIND only supports IDNA2008. Update the "idna" system
test so that it uses one of such symbols rather than one which is
disallowed by both IDNA2003 and IDNA2008.
There is no need to call dns_name_settotextfilter() in setup_system()
because setup_lookup() determines whether IDN output processing should
be enabled for a specific lookup (taking the global setting into
consideration) and calls dns_name_settotextfilter() anyway if it is.
Remove the dns_name_settotextfilter() call from setup_system().
Clean up the parts of configure.in responsible for handling libidn2
detection and adjust other pieces of the build system to match these
cleanups:
- use pkg-config when --with-libidn2 is used without an explicit path,
- look for idn2_to_ascii_lz() rather than idn2_to_ascii_8z() as the
former is used in BIND while the latter is not,
- do not look for idn2_to_unicode_8zlz() as it is present in all
libidn2 versions which have idn2_to_ascii_lz(),
- check whether the <idn2.h> header is usable,
- set LDFLAGS in the Makefile for dig so that, if specified, the
requested libidn2 path is used when linking with libidn2,
- override CPPFLAGS when looking for libidn2 components so that the
configure script does not produce warnings when libidn2 is not
installed system-wide,
- merge the AS_CASE() call into the AS_IF() call below it to simplify
code,
- indicate the default value of --with-libidn2 in "./configure --help"
output,
- use $with_libidn2 rather than $use_libidn2 to better match the name
of the configure script argument,
- stop differentiating between IDN "in" and "out" support, i.e. make
dig either support libidn2 or not; remove WITH_* Autoconf macros and
use a new one, HAVE_LIBIDN2, to determine whether libidn2 support
should be enabled.
This commit reverts the previous change to use system provided
entropy, as (SYS_)getrandom is very slow on Linux because it is
a syscall.
The change introduced in this commit adds a new call isc_nonce_buf
that uses CSPRNG from cryptographic library provider to generate
secure data that can be and must be used for generating nonces.
Example usage would be DNS cookies.
The isc_random() API has been changed to use fast PRNG that is not
cryptographically secure, but runs entirely in user space. Two
contestants have been considered xoroshiro family of the functions
by Villa&Blackman and PCG by O'Neill. After a consideration the
xoshiro128starstar function has been used as uint32_t random number
provider because it is very fast and has good enough properties
for our usage pattern.
The other change introduced in the commit is the more extensive usage
of isc_random_uniform in places where the usage pattern was
isc_random() % n to prevent modulo bias. For usage patterns where
only 16 or 8 bits are needed (DNS Message ID), the isc_random()
functions has been renamed to isc_random32(), and isc_random16() and
isc_random8() functions have been introduced by &-ing the
isc_random32() output with 0xffff and 0xff. Please note that the
functions that uses stripped down bit count doesn't pass our
NIST SP 800-22 based random test.
- Replace external -DOPENSSL/-DPKCS11CRYPTO with properly AC_DEFINEd
HAVE_OPENSSL/HAVE_PKCS11
- Don't enforce the crypto provider from platform.h, just from dst_api.c
and configure scripts
The three functions has been modeled after the arc4random family of
functions, and they will always return random bytes.
The isc_random family of functions internally use these CSPRNG (if available):
1. getrandom() libc call (might be available on Linux and Solaris)
2. SYS_getrandom syscall (might be available on Linux, detected at runtime)
3. arc4random(), arc4random_buf() and arc4random_uniform() (available on BSDs and Mac OS X)
4. crypto library function:
4a. RAND_bytes in case OpenSSL
4b. pkcs_C_GenerateRandom() in case PKCS#11 library
Replace dns_fixedname_init() calls followed by dns_fixedname_name()
calls with calls to dns_fixedname_initname() where it is possible
without affecting current behavior and/or performance.
This patch was mostly prepared using Coccinelle and the following
semantic patch:
@@
expression fixedname, name;
@@
- dns_fixedname_init(&fixedname);
...
- name = dns_fixedname_name(&fixedname);
+ name = dns_fixedname_initname(&fixedname);
The resulting set of changes was then manually reviewed to exclude false
positives and apply minor tweaks.
It is likely that more occurrences of this pattern can be refactored in
an identical way. This commit only takes care of the low-hanging fruit.
Emit fatal failures on locale to ACE encoding
Separate idnout support, disable it for libidn2 < 2.0
Add custom path to libidn. Leave default path for multilib support.
Allow turning off IDN input processing by dig option
Improve documentation, fix support in host
Fix configure changes to adjust help text
Use strlcpy with size guard
Improve IDN variants choosing. Fix idn2 function name.
Remove immediate idn_locale_to_ace and idn_ace_to_locale.
Signed-off-by: Petr Menšík <pemensik@redhat.com>
Added two new configure options:
--with-libidn2 - to enable IDN using GNU libidn2
idnkit, libidn and libidn2 support can not be used at the same time.
NOTE: libidn2 does not support punycode back to Unicode
characters, so support for this is missing.
Signed-off-by: Tomas Hozza <thozza@redhat.com>
Removed iconv, convert directly from locale to ACE
Fix libidn2 and idnkit origin appending
Make IDN options in help less different
Signed-off-by: Petr Menšík <pemensik@redhat.com>
Added new configure option:
--with-libidn - to enable IDN using GNU libidn
Renamed configure option:
--with-idn to --with-idnkit to make the option usage more clear
idnkit and libidn support can not be used at the same time.
Signed-off-by: Tomas Hozza <thozza@redhat.com>
4756. [bug] Interrupting dig could lead to an INSIST failure after
certain errors were encountered while querying a host
whose name resolved to more than one address. Change
4537 increased the odds of triggering this issue by
causing dig to hang indefinitely when certain error
paths were evaluated. dig now also retries TCP queries
(once) if the server gracefully closes the connection
before sending a response. [RT #42832, #45159]
