This commit converts the license handling to adhere to the REUSE
specification. It specifically:
1. Adds used licnses to LICENSES/ directory
2. Add "isc" template for adding the copyright boilerplate
3. Changes all source files to include copyright and SPDX license
header, this includes all the C sources, documentation, zone files,
configuration files. There are notes in the doc/dev/copyrights file
on how to add correct headers to the new files.
4. Handle the rest that can't be modified via .reuse/dep5 file. The
binary (or otherwise unmodifiable) files could have license places
next to them in <foo>.license file, but this would lead to cluttered
repository and most of the files handled in the .reuse/dep5 file are
system test files.
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.
While cleaning up the usage of HAVE_UV_<func> macros, we forgot to
cleanup the HAVE_UV_UDP_CONNECT in the actual code and
HAVE_UV_TRANSLATE_SYS_ERROR and this was causing Windows build to fail
on uv_udp_send() because the socket was already connected and we were
falsely assuming that it was not.
The platforms with autoconf support were not affected, because we were
still checking for the functions from the configure.
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.
With taskmgr running on top of netmgr, the ordering of how the tasks and
netmgr shutdown interacts was wrong as previously isc_taskmgr_destroy()
was waiting until all tasks were properly shutdown and detached. This
responsibility was moved to netmgr, so we now need to do the following:
1. shutdown all the tasks - this schedules all shutdown events onto
the netmgr queue
2. shutdown the netmgr - this also makes sure all the tasks and
events are properly executed
3. Shutdown the taskmgr - this now waits for all the tasks to finish
running before returning
4. Shutdown the netmgr - this call waits for all the netmgr netievents
to finish before returning
This solves the race when the taskmgr object would be destroyed before
all the tasks were finished running in the netmgr loops.
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.
this is similar in structure to the UDP timeout recovery test.
this commit adds a new mechanism to the netmgr test allowing the
listen socket to accept incoming TCP connections but never send
a response. this forces the client to time out on read.
this test sets up a server socket that listens for UDP connections
but never responds. the client will always time out; it should retry
five times before giving up.
This commit merges TLS tests into the common Network Manager unit
tests suite and extends the unit test framework to include support for
additional "ping-pong" style tests where all data could be sent via
lesser number of connections (the behaviour of the old test
suite). The tests for TCP and TLS were extended to make use of the new
mode, as this mode better translates to how the code is used in DoH.
Both TLS and TCP tests now share most of the unit tests' code, as they
are expected to function similarly from a users's perspective anyway.
Additionally to the above, the TLS test suite was extended to include
TLS tests using the connections quota facility.
The isc_nm_tlsdnsconnect() call could end up with two connect callbacks
called when the timeout fired and the TCP connection was aborted,
but the TLS handshake was not complete yet. isc__nm_connecttimeout_cb()
forgot to clean up sock->tls.pending_req when the connect callback was
called with ISC_R_TIMEDOUT, leading to a second callback running later.
A new argument has been added to the isc__nm_*_failed_connect_cb and
isc__nm_*_failed_read_cb functions, to indicate whether the callback
needs to run asynchronously or not.
if a test failed at the beginning of nm_teardown(), the function
would abort before isc_nm_destroy() or isc_tlsctx_free() were reached;
we would then abort when nm_setup() was run for the next test case.
rearranging the teardown function prevents this problem.
The isc_nm_*connect() functions were refactored to always return the
connection status via the connect callback instead of sometimes returning
the hard failure directly (for example, when the socket could not be
created, or when the network manager was shutting down).
This commit changes the connect functions in all the network manager
modules, and also makes the necessary refactoring changes in places
where the connect functions are called.
The full netmgr test suite is unstable when run in CI due to various
timing issues. Previously, we enabled the full test suite only when
CI_ENABLE_ALL_TESTS environment variable was set, but that went against
original intent of running the full suite when an individual developer
would run it locally.
This change disables the full test suite only when running in the CI and
the CI_ENABLE_ALL_TESTS is not set.
The netmgr unit tests were designed to push the system limits to maximum
by sending as many queries as possible in the busy loop from multiple
threads. This mostly works with UDP, but in the stateful protocol where
establishing the connection takes more time, it failed quite often in
the CI. On FreeBSD, this happened more often, because the socket() call
would fail spuriosly making the problem even worse.
This commit does several things to improve reliability:
* return value of isc_nm_<proto>connect() is always checked and retried
when scheduling the connection fails
* The busy while loop has been slowed down with usleep(1000); so the
netmgr threads could schedule the work and get executed.
* The isc_thread_yield() was replaced with usleep(1000); also to allow
the other threads to do any work.
* Instead of waiting on just one variable, we wait for multiple
variables to reach the final value
* We are wrapping the netmgr operations (connects, reads, writes,
accepts) with reference counting and waiting for all the callbacks to
be accounted for.
This has two effects:
a) the isc_nm_t is always clean of active sockets and handles when
destroyed, so it will prevent the spurious INSIST(references == 1)
from isc_nm_destroy()
b) the unit test now ensures that all the callbacks are always called
when they should be called, so any stuck test means that there was
a missing callback call and it is always a real bug
These changes allows us to remove the workaround that would not run
certain tests on systems without port load-balancing.
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
tests of UDP and TCP cases including:
- sending and receiving
- closure sockets without reading or sending
- closure of sockets at various points while sending and receiving
- since the teste is multithreaded, cmocka now aborts tests on the
first failure, so that failures in subthreads are caught and
reported correctly.
