Only comparing the value of the integer passed as the last argument to
MMDB_lookup_sockaddr() against MMDB_SUCCESS is not enough to ensure that
an MMDB lookup was successful - the 'found_entry' field of the
MMDB_lookup_result_s structure returned by that function also needs to
be true or else the remaining contents of that structure should be
ignored as the lookup failed. Extend the relevant logical condition in
get_entry_for() to ensure the latter does not return incorrect MMDB
entries for IP addresses which do not belong to any subnet defined in a
given GeoIP2 database.
Previously, the dns_geoip 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, and
creating the local memory context was moved to named and stored in the
named_g_geoip global context.
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.
Each individual test opened GeoIP databased but the database handles were never
closed. This commit moves the open/close from the individual unit tests into
the _setup and _teardown methods where they really belong.
Instead of the explicit struct initializer with all member, rely on the fact
that static variables are explicitly initialized to 0 if not explicitly
initialized.
- revise mapping of search terms to database types to match the
GeoIP2 schemas.
- open GeoIP2 databases when starting up; close when shutting down.
- clarify the logged error message when an unknown database type
is configured.
- add new geoip ACL subtypes to support searching for continent in
country databases.
- map geoip ACL subtypes to specific MMDB database queries.
- perform MMDB lookups based on subtype, saving state between
queries so repeated lookups for the same address aren't necessary.
- mark the 'geoip-use-ecs' option obsolete; warn when it is used
in named.conf
- prohibit 'ecs' ACL tags in named.conf; note that this is a fatal error
since simply ignoring the tags could make ACLs behave unpredictably
- re-simplify the radix and iptable code
- clean up dns_acl_match(), dns_aclelement_match(), dns_acl_allowed()
and dns_geoip_match() so they no longer take ecs options
- remove the ECS-specific unit and system test cases
- remove references to ECS from the ARM
3936. [func] Added authoritative support for the EDNS Client
Subnet (ECS) option.
ACLs can now include "ecs" elements which specify
an address or network prefix; if an ECS option is
included in a DNS query, then the address encoded
in the option will be matched against "ecs" ACL
elements.
Also, if an ECS address is included in a query,
then it will be used instead of the client source
address when matching "geoip" ACL elements. This
behavior can be overridden with "geoip-use-ecs no;".
When "ecs" or "geoip" ACL elements are used to
select a view for a query, the response will include
an ECS option to indicate which client network the
answer is valid for.
(Thanks to Vincent Bernat.) [RT #36781]
3715. [bug] The region and city databases could fail to
initialize when using some versions of libGeoIP,
causing assertion failures when named was
configured to use them. [RT #35427]
3504. [func] Add support for ACLs based on geographic location,
using MaxMind GeoIP databases. Based on code
contributed by Ken Brownfield <kb@slide.com>.
[RT #30681]
