- ns__client_request() is now called by netmgr with an isc_nmhandle_t
parameter. The handle can then be permanently associated with an
ns_client object.
- The task manager is paused so that isc_task events that may be
triggred during client processing will not fire until after the netmgr is
finished with it. Before any asynchronous event, the client MUST
call isc_nmhandle_ref(client->handle), to prevent the client from
being reset and reused while waiting for an event to process. When
the asynchronous event is complete, isc_nmhandle_unref(client->handle)
must be called to ensure the handle can be reused later.
- reference counting of client objects is now handled in the nmhandle
object. when the handle references drop to zero, the client's "reset"
callback is used to free temporary resources and reiniialize it,
whereupon the handle (and associated client) is placed in the
"inactive handles" queue. when the sysstem is shutdown and the
handles are cleaned up, the client's "put" callback is called to free
all remaining resources.
- because client allocation is no longer handled in the same way,
the '-T clienttest' option has now been removed and is no longer
used by any system tests.
- the unit tests require wrapping the isc_nmhandle_unref() function;
when LD_WRAP is supported, that is used. otherwise we link a
libwrap.so interposer library and use that.
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 is necessary because adding the same hook to multiple views
causes the ISC_LIST link value to become inconsistent; it isn't
noticeable when only one hook action is ever registered at a
given hook point, but it will break things when there are two.
- use a get_hooktab() function to determine the hook table.
- PROCESS_HOOK now jumps to a cleanup tag on failure
- add PROCESS_ALL_HOOKS in query.c, to run all hook functions at
a specified hook point without stopping. this is to be used for
intiialization and destruction functions that must run in every
module.
- 'result' is set in PROCESS_HOOK only when a hook function
interrupts processing.
- revised terminology: a "callback" is now a "hook action"
- remove unused NS_PROCESS_HOOK and NS_PROCESS_HOOK_VOID macros.
- allow multiple "hook" statements at global or view level
- add "optional bracketed text" type for optional parameter list
- load hook module from specified path rather than hardcoded path
- add a hooktable pointer (and a callback for freeing it) to the
view structure
- change the hooktable functions so they no longer update ns__hook_table
by default, and modify PROCESS_HOOK so it uses the view hooktable, if
set, rather than ns__hook_table. (ns__hook_table is retained for
use by unit tests.)
- update the filter-aaaa system test to load filter-aaaa.so
- add a prereq script to check for dlopen support before running
the filter-aaaa system test
not yet done:
- configuration parameters are not being passed to the filter-aaaa
module; the filter-aaaa ACL and filter-aaaa-on-{v4,v6} settings are
still stored in dns_view
- these formerly static helper functions have been moved into client.c
and made external so that they can be used in hook modules as well as
internally in libns: query_newrdataset, query_putrdataset,
query_newnamebuf, query_newname, query_getnamebuf, query_keepname,
query_releasename, query_newdbversion, query_findversion
- made query_recurse() and query_done() into public functions
ns_query_recurse() and ns_query_done() so they can be called from
modules.
- move hooks.h to public include directory
- ns_hooktable_init() initializes a hook table. if NULL is passed in, it
initializes the global hook table
- ns_hooktable_save() saves a pointer to the current global hook table.
- ns_hooktable_reset() replaces the global hook table with different
one
- ns_hook_add() adds hooks at specified hook points in a hook table (or
the global hook table if the specified table is NULL)
- load and unload functions support dlopen() of hook modules (this is
adapted from dyndb and not yet functional)
- began adding new hook points to query.c
