The main intention of PROXY protocol is to pass endpoints information
to a back-end server (in our case - BIND). That means that it is a
valid way to spoof endpoints information, as the addresses and ports
extracted from PROXYv2 headers, from the point of view of BIND, are
used instead of the real connection addresses.
Of course, an ability to easily spoof endpoints information can be
considered a security issue when used uncontrollably. To resolve that,
we introduce 'allow-proxy' and 'allow-proxy-on' ACL options. These are
the only ACL options in BIND that work with real PROXY connections
addresses, allowing a DNS server operator to specify from what clients
and on which interfaces he or she is willing to accept PROXY
headers. By default, for security reasons we do not allow to accept
them.
This commit extends "listen-on" statement with "proxy" options that
allows one to enable PROXYv2 support on a dedicated listener. It can
have the following values:
- "plain" to send PROXYv2 headers without encryption, even in the case
of encrypted transports.
- "encrypted" to send PROXYv2 headers encrypted right after the TLS
handshake.
The AES algorithm for DNS cookies was being kept for legacy reasons, and
it can be safely removed in the next major release. Remove both the AES
usage for DNS cookies and the AES implementation itself.
The lock-file configuration (both from configuration file and -X
argument to named) has better alternatives nowadays. Modern process
supervisor should be used to ensure that a single named process is
running on a given configuration.
Alternatively, it's possible to wrap the named with flock(1).
This is first step in removing the lock-file configuration option, it
marks both the `lock-file` configuration directive and -X option to
named as deprecated.
When -X is used the 'lock-file' option change detection condition
is invalid, because it compares the 'lock-file' option's value to
the '-X' argument's value instead of the older 'lock-file' option
value (which was ignored because of '-X').
Don't warn about changing 'lock-file' option if '-X' is used.
It is obvious that the '!cfg_obj_asstring(obj)' check should be
'cfg_obj_asstring(obj)' instead, because it is an AND logic chain
which further uses 'obj' as a string.
Fix the error.
When 'lock-file <lockfile>' is used in configuration at the same time
as using '-X none' in 'named' invocation, there is an invalid
logic that would lead to a isc_mem_strdup() call on a NULL value.
Also, contradicting to ARM, 'lock-file none' is overriding the '-X'
argument.
Fix the overall logic, and make sure that the '-X' takes precedence to
'lock-file'.
When 'lock-file <lockfile1>' was used in configuration at the same time
as using `-X <lockfile2>` in `named` invocation, there was an invalid
logic that would lead to a double isc_mem_strdup() call on the
<lockfile2> value.
Skip the second allocation if `lock-file` is being used in
configuration, so the <lockfile2> is used only single time.
When using sd_notify(3) to send a message to the service manager
about named being reloaded, systemd also requires the MONOTONIC_USEC
field to be set to the current monotonic time in microseconds,
otherwise the 'systemctl reload' command fails.
Add the MONOTONIC_USEC field to the message.
See 'man 5 systemd.service' for more information.
now that we have the QP chain mechanism, we can convert the
RPZ summary database to use a QP trie instead of an RBT.
also revised comments throughout the file accordingly, and
incidentally cleaned up calls to new_node(), which can no
longer fail.
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.
Instead of high number of dispatches (4 * named_g_udpdisp)[1], make the
dispatches bound to threads and make dns_dispatchset_t create a dispatch
for each thread (event loop).
This required couple of other changes:
1. The dns_dispatch_createudp() must be called on loop, so the isc_tid()
is already initialized - changes to nsupdate and mdig were required.
2. The dns_requestmgr had only a single dispatch per v4 and v6. Instead
of using single dispatch, use dns_dispatchset_t for each protocol -
this is same as dns_resolver.
Add a configuration option, resolver-use-dns64, which when true
will cause named to map IPv4 address to IPv6 addresses using the
view's DNS64 mapping rules when making iterative queries.
instead of allowing a NULL nametree in dns_nametree_covered(),
require nametree to exist, and ensure that the nametrees defined
for view and resolver objects are always created.
name trees can now hold either boolean values or bit fields. the
type is selected when the name tree is created.
the behavior of dns_nametree_add() differs slightly beteween the types:
in a boolean tree adding an existing name will return ISC_R_EXISTS,
but in a bitfield tree it simply sets the specified bit in the bitfield
and returns ISC_R_SUCCESS.
replace the use of RBTs for deny-answer-aliases, the exclude
lists for deny-answer-aliases and deny-answer-addresses, and
dnssec-must-be-secure, with name trees.
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.
Instead of an RBT for the forwarders table, use a QP trie.
We now use reference counting for dns_forwarders_t. When a forwarders
object is retrieved by dns_fwdtable_find(), it must now be explicitly
detached by the caller afterward.
QP tries require stored objects to include their names, so the
the forwarders object now has that. This obviates the need to
pass back a separate 'foundname' value from dns_fwdtable_find().
replace the red-black tree used by the negative trust anchor table
with a QP trie.
because of this change, dns_ntatable_init() can no longer fail, and
neither can dns_view_initntatable(). these functions have both been
changed to type void.
Add an option to enable/disable inline-signing inside the
dnssec-policy clause. The existing inline-signing option that is
set in the zone clause takes priority, but if it is omitted, then the
value that is set in dnssec-policy is taken.
The built-in policies use inline-signing.
This means that if you want to use the default policy without
inline-signing you either have to set it explicitly in the zone
clause:
zone "example" {
...
dnssec-policy default;
inline-signing no;
};
Or create a new policy, only overriding the inline-signing option:
dnssec-policy "default-dynamic" {
inline-signing no;
};
zone "example" {
...
dnssec-policy default-dynamic;
};
This also means that if you are going insecure with a dynamic zone,
the built-in "insecure" policy needs to be accompanied with
"inline-signing no;".
The isc_stats_create() can no longer return anything else than
ISC_R_SUCCESS. Refactor isc_stats_create() and its variants in libdns,
libns and named to just return void.
1. Change the _new, _add and _copy functions to return the new object
instead of returning 'void' (or always ISC_R_SUCCESS)
2. Cleanup the isc_ht_find() + isc_ht_add() usage - the code is always
locked with catzs->lock (mutex), so when isc_ht_find() returns
ISC_R_NOTFOUND, the isc_ht_add() must always succeed.
3. Instead of returning direct iterator for the catalog zone entries,
add dns_catz_zone_for_each_entry2() function that calls callback
for each catalog zone entry and passes two extra arguments to the
callback. This will allow changing the internal storage for the
catalog zone entries.
4. Cleanup the naming - dns_catz_<fn>_<obj> -> dns_catz_<obj>_<fn>, as an
example dns_catz_new_zone() gets renamed to dns_catz_zone_new().
Some 'rndc signing' commands can still be used in conjunction with
'dnssec-policy' because it shows the progress of signing and
private type records can be cleaned up. Allow these commands to be
executed.
However, setting NSEC3 parameters is incompatible with dnssec-policy.
view->adb may be referenced while the view is shutting down as the
zone uses a weak reference to the view and examines view->adb but
dns_view_detach call dns_adb_detach to clear view->adb.
since it is not necessary to find partial matches when looking
up names in a TSIG keyring, we can use a hash table instead of
an RBT to store them.
the tsigkey object now stores the key name as a dns_fixedname
rather than allocating memory for it.
the `name` parameter to dns_tsigkeyring_add() has been removed;
it was unneeded since the tsigkey object already contains a copy
of the name.
the opportunistic cleanup_ring() function has been removed;
it was only slowing down lookups.
the prior practice of passing a dns_name containing the
expanded name of an algorithm to dns_tsigkey_create() and
dns_tsigkey_createfromkey() is unnecessarily cumbersome;
we can now pass the algorithm number instead.
use the ISC_REFCOUNT attach/detach implementation in dns/tsig.c
so that detailed tracing can be used during refactoring.
dns_tsig_keyring_t has been renamed dns_tsigkeyring_t so the type
and the attach/detach function names will match.
it was possible to add a TSIG key to more than one TSIG
keyring at a time, and this was in fact happening with the
session key, which was generated once and then added to the
keyrings for each view as it was configured.
this has been corrected and a REQUIRE added to dns_tsigkeyring_add()
to prevent it from happening again.
isc_loopmgr_pause can't be called before isc_loopmgr_run is
called as the thread ids are not yet valid. If there is a
fatal error before isc_loopmgr_run is run then don't call
isc_loopmgr_pause.
This change makes the zone table lock-free for reads. Previously, the
zone table used a red-black tree, which is not thread safe, so the hot
read path acquired both the per-view mutex and the per-zonetable
rwlock. (The double locking was to fix to cleanup races on shutdown.)
One visible difference is that zones are not necessarily shut down
promptly: it depends on when the qp-trie garbage collector cleans up
the zone table. The `catz` system test checks several times that zones
have been deleted; the test now checks for zones to be removed from
the server configuration, instead of being fully shut down. The catz
test does not churn through enough zones to trigger a gc, so the zones
are not fully detached until the server exits.
After this change, it is still possible to improve the way we handle
changes to the zone table, for instance, batching changes, or better
compaction heuristics.
Add a new configuration option to set how the checkds method should
work. Acceptable values are 'yes', 'no', and 'explicit'.
When set to 'yes', the checkds method is to lookup the parental agents
by querying the NS records of the parent zone.
When set to 'no', no checkds method is enabled. Users should run
the 'rndc checkds' command to signal that DS records are published and
withdrawn.
When set to 'explicit', the parental agents are explicitly configured
with the 'parental-agents' configuration option.
When fatal is called we may be holding memory allocated by OpenSSL.
This may result in the reference count for the FIPS provider not
going to zero and the shared library not being unloaded during
OPENSSL_cleanup. When the shared library is ultimately unloaded,
when all remaining dynamically loaded libraries are freed, we have
already destroyed the memory context we where using to track memory
leaks / late frees resulting in INSIST being called.
Disable triggering the INSIST when fatal has being called.
