Instead of having individual memory contexts scattered across different
files and called different names, add a single memory context called
isc_g_mctx that replaces named_g_mctx and various other global memory
contexts in various utilities and tests.
Locally, clang reported odr-violation:
=================================================================
==588371==ERROR: AddressSanitizer: odr-violation (0x55555556a060):
[1] size=256 'client_addrs' ../tests/ns/netmgr_wrap.c:36:18 in /home/ondrej/Projects/bind9/build/tests/ns/query
[2] size=256 'client_addrs' ../tests/ns/netmgr_wrap.c:36:18 in /home/ondrej/Projects/bind9/build/tests/ns/../libbindtest.so
These globals were registered at these points:
[1]:
#0 0x7ffff785306f in __asan_register_globals ../../../../src/libsanitizer/asan/asan_globals.cpp:350
#1 0x7ffff6a2a303 in call_init ../csu/libc-start.c:145
#2 0x7ffff6a2a303 in __libc_start_main_impl ../csu/libc-start.c:347
#3 0x55555555a084 in _start (/home/ondrej/Projects/bind9/build/tests/ns/query+0x6084) (BuildId: fbe4a3fcf1a249c7d7da69ee8b255a1dbb610c7a)
[2]:
#0 0x7ffff785306f in __asan_register_globals ../../../../src/libsanitizer/asan/asan_globals.cpp:350
#1 0x7ffff7fca71e in call_init elf/dl-init.c:74
#2 0x7ffff7fca823 in call_init elf/dl-init.c:120
#3 0x7ffff7fca823 in _dl_init elf/dl-init.c:121
#4 0x7ffff7fe459f (/lib64/ld-linux-x86-64.so.2+0x1f59f) (BuildId: 281ac1521b4102509b1c7ac7004db7c1efb81796)
==588371==HINT: if you don't care about these errors you may set ASAN_OPTIONS=detect_odr_violation=0
SUMMARY: AddressSanitizer: odr-violation: global 'client_addrs' at ../tests/ns/netmgr_wrap.c:36:18 in /home/ondrej/Projects/bind9/build/tests/ns/query
==588371==ABORTING
Move the client_addrs and client_refs to libtest to prevent this.
There is only a single network manager running on top of the loop
manager (except for tests). Refactor the network manager to be a
singleton (a single instance) and change the unit tests, so that the
shorter read timeouts apply only to a specific handle, not the whole
extra 'connect_nm' network manager instance.
All the applications built on top of the loop manager were required to
create just a single instance of the loop manager. Refactor the loop
manager to not expose this instance to the callers and keep the loop
manager object internal to the isc_loop compilation unit.
This significantly simplifies a number of data structures and calls to
the isc_loop API.
The ns_client_t struct is reset and zero-ed out on every query,
but some fields (query, message, manager) are preserved.
We observe two things:
- The sendbuf field is going to be overwritten anyway, there's
no need to zero it out.
- The fields are copied out when the struct is zero-ed out, and
then copied back in. For the query field (which is 896 bytes)
this is very inefficient.
This commit makes the reset more efficient avoiding to unnecessary
zero-ing and copy.
When loading a primary zone for the first time, if the zonefile
does not exist but an "initial-file" option has been set, then a
new file will be copied into place from the path specified by
"initial-file".
This can be used to simplify the process of adding new zones. For
instance, a template zonefile could be used by running:
$ rndc addzone example.com \
'{ type primary; file "example.db"; initial-file "template.db"; };'
the isc_mem allocation functions can no longer fail; as a result,
ISC_R_NOMEMORY is now rarely used: only when an external library
such as libjson-c or libfstrm could return NULL. (even in
these cases, arguably we should assert rather than returning
ISC_R_NOMEMORY.)
code and comments that mentioned ISC_R_NOMEMORY have been
cleaned up, and the following functions have been changed to
type void, since (in most cases) the only value they could
return was ISC_R_SUCCESS:
- dns_dns64_create()
- dns_dyndb_create()
- dns_ipkeylist_resize()
- dns_kasp_create()
- dns_kasp_key_create()
- dns_keystore_create()
- dns_order_create()
- dns_order_add()
- dns_peerlist_new()
- dns_tkeyctx_create()
- dns_view_create()
- dns_zone_setorigin()
- dns_zone_setfile()
- dns_zone_setstream()
- dns_zone_getdbtype()
- dns_zone_setjournal()
- dns_zone_setkeydirectory()
- isc_lex_openstream()
- isc_portset_create()
- isc_symtab_create()
(the exception is dns_view_create(), which could have returned
other error codes in the event of a crypto library failure when
calling isc_file_sanitize(), but that should be a RUNTIME_CHECK
anyway.)
coccinelle v1.1 trips over a superfluous isc_mem_get() NULL check in
tests/libtest/ns.c and reports the following failure in CI:
EXN: Failure("rule starting on line 26: already tagged token:\nC code context\nFile \"./tests/libtest/ns.c\", line 350, column 1, charpos = 7939\n around = 'if',\n whole content = \tif (qctx != NULL) {") in ./tests/libtest/ns.c
Stop using ns_listenlist_default() to set the default listen-on
and listen-on-v6 configuration. Instead, configure these options
using the default values in config.c.
Remove the complicated mechanism that could be (in theory) used by
external libraries to register new categories and modules with
statically defined lists in <isc/log.h>. This is similar to what we
have done for <isc/result.h> result codes. All the libraries are now
internal to BIND 9, so we don't need to provide a mechanism to register
extra categories and modules.
When automatic-interface-scan is disabled, the route socket was still
being opened. Add new API to connect / disconnect from the route socket
only as needed.
Additionally, move the block that disables periodic interface rescans to
a place where it actually have access to the configuration values.
Previously, the values were being checked before the configuration was
loaded.
As ns_query_init() cannot fail now, remove the error paths, especially
in ns__client_setup() where we now don't have to care what to do with
the connection if setting up the client could fail. It couldn't fail
even before, but now it's formal.
View matching on an incoming query checks the query's signature,
which can be a CPU-heavy task for a SIG(0)-signed message. Implement
an asynchronous mode of the view matching function which uses the
offloaded signature checking facilities, and use it for the incoming
queries.
In order to protect from a malicious DNS client that sends many
queries with a SIG(0)-signed message, add a quota of simultaneously
running SIG(0) checks.
This protection can only help when named is using more than one worker
threads. For example, if named is running with the '-n 4' option, and
'sig0checks-quota 2;' is used, then named will make sure to not use
more than 2 workers for the SIG(0) signature checks in parallel, thus
leaving the other workers to serve the remaining clients which do not
use SIG(0)-signed messages.
That limitation is going to change when SIG(0) signature checks are
offloaded to "slow" threads in a future commit.
The 'sig0checks-quota-exempt' ACL option can be used to exempt certain
clients from the quota requirements using their IP or network addresses.
The 'sig0checks-quota-maxwait-ms' option is used to define a maximum
amount of time for named to wait for a quota to appear. If during that
time no new quota becomes available, named will answer to the client
with DNS_R_REFUSED.
by default, QPDB is the database used by named and all tools and
unit tests. the old default of RBTDB can now be restored by using
"configure --with-zonedb=rbt --with-cachedb=rbt".
some tests have been fixed so they will work correctly with either
database.
CHANGES and release notes have been updated to reflect this change.
replace the string "rbt" throughout BIND with "qp" so that
qpdb databases will be used by default instead of rbtdb.
rbtdb databases can still be used by specifying "database rbt;"
in a zone statement.
Instead of creating new memory pools for each new dns_message, change
dns_message_create() method to optionally accept externally created
dns_fixedname_t and dns_rdataset_t memory pools. This allows us to
preallocate the memory pools in ns_client and dns_resolver units for the
lifetime of dns_resolver_t and ns_clientmgr_t.
Reusing TCP connections with dns_dispatch_gettcp() used linear linked
list to lookup existing outgoing TCP connections that could be reused.
Replace the linked list with per-loop cds_lfht hashtable to speedup the
lookups. We use cds_lfht because it allows non-unique node insertion
that we need to check for dispatches in different connection states.
The dns_dispatchmgr object was only set in the dns_view object making it
prone to use-after-free in the dns_xfrin unit when shutting down named.
Remove dns_view_setdispatchmgr() and optionally pass the dispatchmgr
directly to dns_view_create() when it is attached and not just assigned,
so the dns_dispatchmgr doesn't cease to exist too early.
The dns_view_getdnsdispatchmgr() is now protected by the RCU lock, the
dispatchmgr reference is incremented, so the caller needs to detach from
it, and the function can return NULL in case the dns_view has been
already shut down.
The isc_time_now() and isc_time_now_hires() were used inconsistently
through the code - either with status check, or without status check,
or via TIME_NOW() macro with RUNTIME_CHECK() on failure.
Refactor the isc_time_now() and isc_time_now_hires() to always fail when
getting current time has failed, and return the isc_time_t value as
return value instead of passing the pointer to result in the argument.
Instead of marking the unused entities with UNUSED(x) macro in the
function body, use a `ISC_ATTR_UNUSED` attribute macro that expans to
C23 [[maybe_unused]] or __attribute__((__unused__)) as fallback.
as there is no further use of isc_task in BIND, this commit removes
it, along with isc_taskmgr, isc_event, and all other related types.
functions that accepted taskmgr as a parameter have been cleaned up.
as a result of this change, some functions can no longer fail, so
they've been changed to type void, and their callers have been
updated accordingly.
the tasks table has been removed from the statistics channel and
the stats version has been updated. dns_dyndbctx has been changed
to reference the loopmgr instead of taskmgr, and DNS_DYNDB_VERSION
has been udpated as well.
DSCP has not been fully working since the network manager was
introduced in 9.16, and has been completely broken since 9.18.
This seems to have caused very few difficulties for anyone,
so we have now marked it as obsolete and removed the
implementation.
To ensure that old config files don't fail, the code to parse
dscp key-value pairs is still present, but a warning is logged
that the feature is obsolete and should not be used. Nothing is
done with configured values, and there is no longer any
range checking.
The only function left in the isc_resource API was setting the file
limit. Replace the whole unit with a simple getrlimit to check the
maximum value of RLIMIT_NOFILE and set the maximum back to rlimit_cur.
This is more compatible than trying to set RLIMIT_UNLIMITED on the
RLIMIT_NOFILE as it doesn't work on Linux (see man 5 proc on
/proc/sys/fs/nr_open), neither it does on Darwin kernel (see man 2
getrlimit).
The only place where the maximum value could be raised under privileged
user would be BSDs, but the `named_os_adjustnofile()` were not called
there before. We would apply the increased limits only on Linux and Sun
platforms.
All we need for compression is a very small hash set of compression
offsets, because most of the information we need (the previously added
names) can be found in the message using the compression offsets.
This change combines dns_compress_find() and dns_compress_add() into
one function dns_compress_name() that both finds any existing suffix,
and adds any new prefix to the table. The old split led to performance
problems caused by duplicate names in the compression context.
Compression contexts are now either small or large, which the caller
chooses depending on the expected size of the message. There is no
dynamic resizing.
There is a behaviour change: compression now acts on all the labels in
each name, instead of just the last few.
A small benchmark suggests this is about 2x faster.
Previously:
* applications were using isc_app as the base unit for running the
application and signal handling.
* networking was handled in the netmgr layer, which would start a
number of threads, each with a uv_loop event loop.
* task/event handling was done in the isc_task unit, which used
netmgr event loops to run the isc_event calls.
In this refactoring:
* the network manager now uses isc_loop instead of maintaining its
own worker threads and event loops.
* the taskmgr that manages isc_task instances now also uses isc_loopmgr,
and every isc_task runs on a specific isc_loop bound to the specific
thread.
* applications have been updated as necessary to use the new API.
* new ISC_LOOP_TEST macros have been added to enable unit tests to
run isc_loop event loops. unit tests have been updated to use this
where needed.
There was a proposal in the late 1990s that it might, but it turned
out to be unworkable. See RFC 6891, Extension Mechanisms for
DNS (EDNS(0)), section 5, Extended Label Types.
The remnants of the code that supported this in BIND are redundant.
Move the libtest code into a 'libtest' subdirectory and make it
one of the SUBDIRS in the tests Makefile. having it at the top level
required having "." as one of the subdirs, and that caused the
unit tests to be executed twice.
