this function sets the read timeout for the socket associated
with a netmgr handle and, if the timer is running, resets it.
for TCPDNS sockets it also sets the read timeout and resets the
timer on the outer TCP socket.
- isc_nm_tcpdnsconnect() sets up up an outgoing TCP DNS connection.
- isc_nm_tcpconnect(), _udpconnect() and _tcpdnsconnect() now take a
timeout argument to ensure connections time out and are correctly
cleaned up on failure.
- isc_nm_read() now supports UDP; it reads a single datagram and then
stops until the next time it's called.
- isc_nm_cancelread() now runs asynchronously to prevent assertion
failure if reading is interrupted by a non-network thread (e.g.
a timeout).
- isc_nm_cancelread() can now apply to UDP sockets.
- added shim code to support UDP connection in versions of libuv
prior to 1.27, when uv_udp_connect() was added
all these functions will be used to support outgoing queries in dig,
xfrin, dispatch, etc.
1. The isc__nm_tcp_send() and isc__nm_tcp_read() was not checking
whether the socket was still alive and scheduling reads/sends on
closed socket.
2. The isc_nm_read(), isc_nm_send() and isc_nm_resumeread() have been
changed to always return the error conditions via the callbacks, so
they always succeed. This applies to all protocols (UDP, TCP and
TCPDNS).
Attaching and detaching handle pointers will make it easier to
determine where and why reference counting errors have occurred.
A handle needs to be referenced more than once when multiple
asynchronous operations are in flight, so callers must now maintain
multiple handle pointers for each pending operation. For example,
ns_client objects now contain:
- reqhandle: held while waiting for a request callback (query,
notify, update)
- sendhandle: held while waiting for a send callback
- fetchhandle: held while waiting for a recursive fetch to
complete
- updatehandle: held while waiting for an update-forwarding
task to complete
control channel connection objects now contain:
- readhandle: held while waiting for a read callback
- sendhandle: held while waiting for a send callback
- cmdhandle: held while an rndc command is running
httpd connections contain:
- readhandle: held while waiting for a read callback
- sendhandle: held while waiting for a send callback
- rename isc_nmsocket_t->tcphandle to statichandle
- cancelread functions now take handles instead of sockets
- add a 'client' flag in socket objects, currently unused, to
indicate whether it is to be used as a client or server socket
While
if (isc_refcount_decrement() == 1) { // memory_order_release
isc_refcount_destroy(); // memory_order_acquire
...
}
is theoretically the most efficent in practice, using
memory_order_acq_rel produces the same code on x86_64 and doesn't
trigger tsan data races (which use a idealistic model) if
isc_refcount_destroy() is not called immediately. In fact
isc_refcount_destroy() could be removed if we didn't want
to check for the count being 0 when isc_refcount_destroy() is
called.
https://stackoverflow.com/questions/49112732/memory-order-in-shared-pointer-destructor
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
When pk11_numbits() is passed a user provided input that contains all
zeroes (via crafted DNS message), it would crash with assertion
failure. Fix that by properly handling such input.
Created isc_refcount_decrement_expect macro to test conditionally
the return value to ensure it is in expected range. Converted
unchecked isc_refcount_decrement to use isc_refcount_decrement_expect.
Converted INSIST(isc_refcount_decrement()...) to isc_refcount_decrement_expect.
The stdatomic shims for non-C11 compilers (Windows, old gcc, ...) and
mutexatomic implemented only and minimal subset of the atomic types.
This commit adds 16-bit operations for Windows and all atomic types as
defined in standard.
the blackhole ACL was accidentally disabled with respect to client
queries during the netmgr conversion.
in order to make this work for TCP, it was necessary to add a return
code to the accept callback functions passed to isc_nm_listentcp() and
isc_nm_listentcpdns().
The isc_nm_cancelread() function cancels reading on a connected
socket and calls its read callback function with a 'result'
parameter of ISC_R_CANCELED.
the isc_nm_tcpconnect() function establishes a client connection via
TCP. once the connection is esablished, a callback function will be
called with a newly created network manager handle.
there is no need for a caller to reference-count socket objects.
they need tto be able tto close listener sockets (i.e., those
returned by isc_nm_listen{udp,tcp,tcpdns}), and an isc_nmsocket_close()
function has been added for that. other sockets are only accessed via
handles.
when built with "configure --enable-singletrace", named will produce
detailed query logging at the highest debug level for any query with
query ID zero.
this enables monitoring of the progress of a single query by specifying
the QID using "dig +qid=0". the "client" logging category should be set
to a low severity level to suppress logging of other queries. (the
chance of another query using QID=0 at the same time is only 1 in 2^16.)
"--enable-singletrace" turns on "--enable-querytrace" as well, so if the
logging severity is not lowered, all other queries will be logged
verbosely as well. compiling with either of these options will impair
query performance; they should only be turned on when testing or
troubleshooting.
Instead of using bind() and passing the listening socket to the children
threads using uv_export/uv_import use one thread that does the accepting,
and then passes the connected socket using uv_export/uv_import to a random
worker. The previous solution had thundering herd problems (all workers
waking up on one connection and trying to accept()), this one avoids this
and is simpler.
The tcp clients quota is simplified with isc_quota_attach_cb - a callback
is issued when the quota is available.
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
The pk11/constants.h header contained static CK_BYTE arrays and
we had to use #defines to pull only those we need. This commit
changes the constants to only define byte arrays with the content
and either use them directly or define the CK_BYTE arrays locally
where used.
We introduce a isc_quota_attach_cb function - if ISC_R_QUOTA is returned
at the time the function is called, then a callback will be called when
there's quota available (with quota already attached). The callbacks are
organized as a LIFO queue in the quota structure.
It's needed for TCP client quota - with old networking code we had one
single place where tcp clients quota was processed so we could resume
accepting when the we had spare slots, but it's gone with netmgr - now
we need to notify the listener/accepter that there's quota available so
that it can resume accepting.
Remove unused isc_quota_force() function.
The isc_quote_reserve and isc_quota_release were used only internally
from the quota.c and the tests. We should not expose API we are not
using.
tcpdns used transport-specific functions to operate on the outer socket.
Use generic ones instead, and select the proper call in netmgr.c.
Make the missing functions (e.g. isc_nm_read) generic and add type-specific
calls (isc__nm_tcp_read). This is the preparation for netmgr TLS layer.
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.
The <isc/md.h> header directly included <openssl/evp.h> header which
enforced all users of the libisc library to explicitly list the include
path to OpenSSL and link with -lcrypto. By hiding the specific
implementation into the private namespace, we no longer enforce this.
In the long run, this might also allow us to switch cryptographic
library implementation without affecting the downstream users.
While making the isc_md_type_t type opaque, the API using the data type
was changed to use the pointer to isc_md_type_t instead of using the
type directly.
The <isc/md.h> header directly included <openssl/hmac.h> header which
enforced all users of the libisc library to explicitly list the include
path to OpenSSL and link with -lcrypto. By hiding the specific
implementation into the private namespace, we no longer enforce this.
In the long run, this might also allow us to switch cryptographic
library implementation without affecting the downstream users.
The two "functions" that isc/safe.h declared before were actually simple
defines to matching OpenSSL functions. The downside of the approach was
enforcing all users of the libisc library to explicitly list the include
path to OpenSSL and link with -lcrypto. By hiding the specific
implementation into the private namespace changing the defines into
simple functions, we no longer enforce this. In the long run, this
might also allow us to switch cryptographic library implementation
without affecting the downstream users.
The previous commit removed the code related to the internal symbol
table. On platforms where available, we can now use backtrace_symbols()
to print more verbose symbols table to the output.
As there's now general availability of backtrace() and
backtrace_symbols() functions (see below), the commit also removes the
usage of glibc internals and the custom stack tracing.
* backtrace(), backtrace_symbols(), and backtrace_symbols_fd() are
provided in glibc since version 2.1.
* backtrace(), backtrace_symbols(), and backtrace_symbols_fd() first
appeared in Mac OS X 10.5.
* The backtrace() library of functions first appeared in NetBSD 7.0 and
FreeBSD 10.0.
