Commit Graph

13642 Commits

Author SHA1 Message Date
Evan Hunt
157d7bd0e9 incidental cleanups
the 'dipsatchmgr->state' was never set, so the MGR_IS_SHUTTINGDOWN
macro was always false. both of these have been removed.

renamed the 'dispatch->state' field to 'tcpstate' to make its purpose
less ambiguous.

changed an FCTXTRACE log message from "response did not match question"
to the more correctly descriptive "invalid question section".
2021-12-08 10:22:03 -08:00
Evan Hunt
5f82fc11a9 prevent a shutdown hang on non-matching TCP responses
When a non-matching DNS response is received by the resolver,
it calls dns_dispatch_getnext() to resume reading. This is necessary
for UDP but not for TCP, because TCP connections automatically
resume reading after any valid DNS response.

This commit adds a 'tcpreading' flag to TCP dispatches, so that
`dispatch_getnext()` can be called multiple times without subsequent
calls having any effect.
2021-12-08 10:22:03 -08:00
Ondřej Surý
57d0fabadd Stop leaking mutex in nmworker and cond in nm socket
On FreeBSD, the pthread primitives are not solely allocated on stack,
but part of the object lives on the heap.  Missing pthread_*_destroy
causes the heap memory to grow and in case of fast lived object it's
possible to run out-of-memory.

Properly destroy the leaking mutex (worker->lock) and
the leaking condition (sock->cond).
2021-12-08 17:58:53 +01:00
Ondřej Surý
c6f3e12fe7 Reduce the number of hazard pointers
Previously, we set the number of the hazard pointers to be 4 times the
number of workers because the dispatch ran on the old socket code.
Since the old socket code was removed there's a smaller number of
threads, namely:

 - 1 main thread
 - 1 timer thread
 - <n> netmgr threads
 - <n> threadpool threads

Set the number of hazard pointers to 2 + 2 * workers.
2021-12-07 21:12:53 +01:00
Ondřej Surý
15ce1737fa Fix the isc_hp initialization and memory usage
Previously, the isc_hp_init() could not lower the value of
isc__hp_max_threads, but because of a mistake the isc__hp_max_threads
would be set to HP_MAX_THREADS (e.g. 128 threads) thus it would be
always set to 128.  This would result in increased memory usage even
when small number of workers were in use.

Change the default value of isc__hp_max_threads to be 1.

Additionally, enforce the max_hps value in isc_hp_new() to be smaller or
equal to HP_MAX_HPS.  The only user is isc_queue which uses just 1
hazard pointer, so it's only theoretical issue.
2021-12-07 20:41:46 +01:00
Petr Špaček
74d83910d5 Mark broken-nsec option as deprecated
It's unclear if we are going to keep it or not, so let's mark it as
deprecated for a good measure. It's easier to un-deprecate it than the
other way around.
2021-12-06 16:55:55 +01:00
Evan Hunt
4d4cea243a restore the fetch lifetime timer
the lifetime expiry timer for the fetch context was removed
when we switched to using in-band netmgr timeouts. however,
it turns out some dependency loops can occur between a fetch
and the ADB the validator; these deadlocks were formerly broken
when the timer fired, and now there's no timer. we can fix these
errors individually, but in the meantime we don't want the server
to get hung at shutdown because of dangling fetches.

this commit puts back a single timer, which fires two seconds
after the fetch should have completed, and shuts it down. it also
logs a message at level INFO so we know about the problems when
they occur.
2021-12-03 09:49:24 +01:00
Mark Andrews
0aaaa8768f Reject NSEC records with next field with \000 label
A number of DNS implementation produce NSEC records with bad type
maps that don't contain types that exist at the name leading to
NODATA responses being synthesize instead of the records in the
zone.  NSEC records with these bad type maps often have the NSEC
NSEC field set to '\000.QNAME'.  We look for the first label of
this pattern.

e.g.
	example.com NSEC \000.example.com SOA NS NSEC RRSIG
	example.com RRRSIG NSEC ...
	example.com SOA ...
	example.com RRRSIG SOA ...
	example.com NS ...
	example.com RRRSIG NS ...
	example.com A ...
	example.com RRRSIG A ...

	A is missing from the type map.

This introduces a temporary option 'reject-000-label' to control
this behaviour.
2021-12-02 14:27:18 +01:00
Mark Andrews
3faccb16cc Add server christmas tree test
This sets as many server options as possible at once to detect
cut-and-paste bugs when implementing new server options in peer.c.
Most of the accessor functions are similar and it is easy to miss
updating a macro name or structure element name when adding new
accessor functions.

checkconf/setup.sh is there to minimise the difference to branches
with optional server options where the list is updated at runtime.
2021-12-02 14:27:18 +01:00
Mark Andrews
733f58a7a5 Allow servers that emit broken NSEC records to be identified
'server <prefix> { broken-nsec yes; };' can now be used to stop
NSEC records from negative responses from servers in the given
prefix being cached and hence available to synth-from-dnssec.
2021-12-02 14:27:14 +01:00
Mark Andrews
454c29046f Check that SOA and DNSKEY are consistent in NSEC typemaps
If there is a SOA record present then there should also be a
DNSKEY record present as the DNSKEY is supposed to live at the
zone apex like the SOA.
2021-12-02 14:24:37 +01:00
Mark Andrews
5252985a21 Look for covering NSEC under two more conditions
1) when after processing a node there where no headers that
   contained active records.

   When

       if (check_stale_header(node, header, &locktype, lock, &search,
			      &header_prev);

   succeeds or

       if (EXISTS(header) && !ANCIENT(header))

   fails for all entries in the list leading to 'empty_node' remaining
   true.

   If there is are no active records we know nothing about the
   current state of the name so we treat is as ISC_R_NOTFOUND.

2) when there was a covering NOQNAME proof found or all the
   active headers where negative.

   When

	if (header->noqname != NULL &&
	    header->trust == dns_trust_secure)

   succeeds or

	if (!NEGATIVE(header))

   never succeeds.  Under these conditions there could (should be for
   found_noqname) be a covering NSEC earlier in the tree.
2021-12-02 14:24:37 +01:00
Mark Andrews
3fa3b11ef8 Add synthesis of NODATA at wildcard
The old code rejected NSEC that proved the wildcard name existed
(exists).  The new code rejects NSEC that prove that the wildcard
name exists and that the type exists (exists && data) but accept
NSEC that prove the wildcard name exists.

query_synthnxdomain (renamed query_synthnxdomainnodata) already
took the NSEC records and added the correct records to the message
body for NXDOMAIN or NODATA responses with the above change.  The
only additional change needed was to ensure the correct RCODE is
set.
2021-12-02 14:24:37 +01:00
Mark Andrews
4bdd5a9953 Ignore NSEC records without RRSIG and NSEC present
dns_nsec_noexistnodata now checks that RRSIG and NSEC are
present in the type map.  Both types should be present in
a correctly constructed NSEC record.  This check is in
addition to similar checks in resolver.c and validator.c.
2021-12-02 14:18:42 +01:00
Mark Andrews
8ff2c133b5 Add dns_nsec_requiredtypespresent
checks an NSEC rdataset to ensure that both NSEC and RRSIG are
present in the type map.  These types are required for the NSEC
to be valid
2021-12-02 14:18:42 +01:00
Mark Andrews
43316a40a0 Record how often DNS_R_COVERINGNSEC is returned from the cache
reported as "covering nsec returned" when dumping cache stats
and as "CoveringNSEC" in json and xml cache statistics.
2021-12-02 14:18:41 +01:00
Mark Andrews
62dd9ec9c1 Report Cache NSEC auxilary database size 2021-12-02 14:18:41 +01:00
Mark Andrews
85bfcaeb2e Extend dns_db_nodecount to access auxilary rbt node counts
dns_db_nodecount can now be used to get counts from the auxilary
rbt databases.  The existing node count is returned by
tree=dns_dbtree_main.  The nsec and nsec3 node counts by dns_dbtree_nsec
and dns_dbtree_nsec3 respectively.
2021-12-02 14:18:41 +01:00
Mark Andrews
c8a7f92b9e Allow "black lies" to be cached
"black lies" differ from "white lies" in that the owner name of the
NSEC record matches the QNAME and the intent is to return NODATA
instead of NXDOMAIN for all types.  Caching this NSEC does not lead
to unexpected behaviour on synthesis when the QNAME matches the
NSEC owner which it does for the the general "white lie" response.

"black lie" QNAME NSEC \000.QNAME NSEC RRSIG

"white lie" QNAME- NSEC QNAME+ NSEC RRSIG

where QNAME- is a name that is close to QNAME but sorts before QNAME
and QNAME+ is a that is close to QNAME but sorts after QNAME.

Black lies are safe to cache as they don't bring into existence
names that are not intended to exist.  "Black lies" intentional change
NXDOMAIN to NODATA. "White lies" bring QNAME- into existence and named
would synthesis NODATA for QNAME+ if it is queried for that name
instead of discovering the, presumable, NXDOMAIN response.

Note rejection NSEC RRsets with NEXT names starting with the label
'\000' renders this change ineffective (see reject-000-label).
2021-12-02 14:18:41 +01:00
Mark Andrews
6fae151c9d Do not cache minimal NSEC records (NSEC + RRSIG only)
these are not useful for dnssec synthesis as they can result in
false NODATA responses and just consume cache memory
2021-12-02 14:18:41 +01:00
Mark Andrews
27acf56ba3 Remove unnecessary dns_rbt_fullnamefromnode call
the results from dns_rbt_fullnamefromnode are not used.
2021-12-02 14:18:40 +01:00
Mark Andrews
89542b8a15 Count DNS_R_COVERINGNSEC as a cache {query}hit
Note when synthesising answer involving wildcards we look in the
cache multiple times, once for the QNAME and once for the wildcard
name which is constucted by looking at the names from the covering
NSEC return by the QNAME miss.
2021-12-02 14:18:40 +01:00
Mark Andrews
3a5652ccb1 Rework rbtdb.c:find_coveringnsec() to use the auxilary nsec rbt
this improves the performance of looking for NSEC and RRSIG(NSEC)
records in the cache by skipping lots of nodes in the main trees
in the cache without these records present.  This is a simplified
version of previous_closest_nsec() which uses the same underlying
mechanism to look for NSEC and RRSIG(NSEC) records in authorative
zones.

The auxilary NSEC tree was already being maintained as a side effect
of looking for the covering NSEC in large zones where there can be
lots of glue records that needed to be skipped.  Nodes are added
to the tree whenever a NSEC record is added to the primary tree.
They are removed when the corresponding node is removed from the
primary tree.

Having nodes in the NSEC tree w/o NSEC records in the primary tree
should not impact on synth-from-dnssec efficiency as that node would
have held the NSEC we would have been needed to synthesise the
response.  Removing the node when the NSEC RRset expires would only
cause rbtdb to return a NSEC which would be rejected at a higher
level.
2021-12-02 14:18:40 +01:00
Ondřej Surý
20ac73eb22 Improve the logging on failed TCP accept
Previously, when TCP accept failed, we have logged a message with
ISC_LOG_ERROR level.  One common case, how this could happen is that the
client hits TCP client quota and is put on hold and when resumed, the
client has already given up and closed the TCP connection.  In such
case, the named would log:

    TCP connection failed: socket is not connected

This message was quite confusing because it actually doesn't say that
it's related to the accepting the TCP connection and also it logs
everything on the ISC_LOG_ERROR level.

Change the log message to "Accepting TCP connection failed" and for
specific error states lower the severity of the log message to
ISC_LOG_INFO.
2021-12-02 13:50:00 +01:00
Evan Hunt
fa8f409af2 On non-matching answer, check for missed timeout
A TCP connection may be held open past its proper timeout if it's
receiving a stream of DNS responses that don't match any queries.
In this case, we now check whether the oldest query should have timed
out.
2021-12-01 11:45:55 -08:00
Ondřej Surý
ba1cadf14a Tear down the TCP connection on too many unexpected DNS messages
When the outgoing TCP dispatch times-out active response, we might still
receive the answer during the lifetime of the connection.  Previously,
we would just ignore any non-matching DNS answers, which would allow the
server to feed us with otherwise valid DNS answer and keep the
connection open.

Add a counter for timed-out DNS queries over TCP and tear down the whole
TCP connection if we receive unexpected number of DNS answers.
2021-12-01 11:45:55 -08:00
Ondřej Surý
c84ed5056e Refactor tcp_recv()
The tcp_recv() function used lot of gotos that made the function hard to
read.  Refactor the function by splitting it into smaller logical chunks.
2021-12-01 11:45:55 -08:00
Ondřej Surý
10f4f1a250 Shutdown all TCP connection on invalid DNS message
Previously, when invalid DNS message is received over TCP we throw the
garbage DNS message away and continued looking for valid DNS message
that would match our outgoing queries.  This logic makes sense for UDP,
because anyone can send DNS message over UDP.

Change the logic that the TCP connection is closed when we receive
garbage, because the other side is acting malicious.
2021-12-01 11:45:55 -08:00
Ondřej Surý
9230473324 Shutdown all active TCP connections on error
When outgoing TCP connection was prematurely terminated (f.e. with
connection reset), the dispatch code would not cleanup the resources
used by such connection leading to dangling dns_dispentry_t entries.
2021-12-01 11:45:55 -08:00
Artem Boldariev
5f859d8a98 TLS context handling code: Fix an abort on ancient OpenSSL version
There was a logical bug when setting a list of enabled TLS protocols,
which may lead to a crash (an abort()) on systems with ancient OpenSSL
versions.

The problem was due to the fact that we were INSIST()ing on supporting
all of the TLS versions, while checking only for mentioned in the
configuration was implied.
2021-12-01 12:00:30 +02:00
Artem Boldariev
69cef39099 Add 'tls' validation for XoT enabled primaries
This commit ensure that the 'tls' name specified in the 'primaries'
clause of a 'zone' statement is a valid one.

Prior to that such a name would be silently accepted, leading to
silent XFRs-via-TLS failures.
2021-12-01 12:00:29 +02:00
Artem Boldariev
7843fb4ece XoT: add support for client-side TLS parameters
This commit adds support for client-side TLS parameters to XoT.

Prior to this commit all client-side TLS contexts were using default
parameters only, ignoring the options from the BIND's configuration
file.

Currently, the following 'tls' parameters are supported:

- protocols;
- ciphers;
- prefer-server-ciphers.
2021-12-01 12:00:28 +02:00
Artem Boldariev
0ee6f66cbd Integrate extended ACLs syntax featuring 'port' and 'transport' opts
This commit completes the integration of the new, extended ACL syntax
featuring 'port' and 'transport' options.

The runtime presentation and ACL loading code are extended to allow
the syntax to be used beyond the 'allow-transfer' option (e.g. in
'acl' definitions and other 'allow-*' options) and can be used to
ultimately extend the ACL support with transport-only
ACLs (e.g. 'transport-acl tls-acl port 853 transport tls'). But, due
to fundamental nature of such a change, it has not been completed as a
part of 9.17.X release series due to it being close to 9.18 stable
release status. That means that we do not have enough time to fully
test it.

The complete integration is planned as a part of 9.19.X release
series.

The code was manually verified to work as expected by temporarily
enabling the extended syntax for 'acl' statements and 'allow-query'
options, including ACL merging, negated ACLs.
2021-11-30 12:20:22 +02:00
Artem Boldariev
af2d065c21 Extend ACL syntax handling code with 'port' and 'transport' options
This commit extends ACL syntax handling code with 'port' and
'transport' options. Currently, the extended syntax is available only
for allow-transfer options.
2021-11-30 12:20:22 +02:00
Artem Boldariev
f0e18f3927 Add isc_nm_has_encryption()
This commit adds an isc_nm_has_encryption() function intended to check
if a given handle is backed by a connection which uses encryption.
2021-11-30 12:20:22 +02:00
Artem Boldariev
07cf827b0b Add isc_nm_socket_type()
This commit adds an isc_nm_socket_type() function which can be used to
obtain a handle's socket type.

This change obsoletes isc_nm_is_tlsdns_handle() and
isc_nm_is_http_handle(). However, it was decided to keep the latter as
we eventually might end up supporting multiple HTTP versions.
2021-11-30 12:20:22 +02:00
Artem Boldariev
78b73d0865 Disable unused 'tls' clause options: 'ca-file' and 'hostname'
This commit disables the unused 'tls' clause options. For these some
backing code exists, but their values are not really used anywhere,
nor there are sufficient syntax tests for them.

These options are only disabled temporarily, until TLS certificate
verification gets implemented.
2021-11-29 14:02:48 +02:00
Artem Boldariev
b211fff4cb TLS stream: disable TLS I/O debug log message by default
This commit makes the TLS stream code to not issue mostly useless
debug log message on error during TLS I/O. This message was cluttering
logs a lot, as it can be generated on (almost) any non-clean TLS
connection termination, even in the cases when the actual query
completed successfully. Nor does it provide much value for end-users,
yet it can occasionally be seen when using dig and quite often when
running BIND over a publicly available network interface.
2021-11-26 10:23:17 +02:00
Artem Boldariev
0b0c29dd51 DoH: Remove unneeded isc__nmsocket_prep_destroy() call
This commit removes unneeded isc__nmsocket_prep_destroy() call on ALPN
negotiation failure, which was eventually causing the TLS handle to
leak.

This call is not needed, as not attaching to the transport (TLS)
handle should be enough. At this point it seems like a kludge from
earlier days of the TLS code.
2021-11-26 10:23:17 +02:00
Matthijs Mekking
89f4f8f0c8 Add OPENSSL_cleanup to tls_shutdown function
This prevents a direct leak in OPENSSL_init_crypto (called from
OPENSSL_init_ssl).

Add shim version of OPENSSL_cleanup because it is missing in LibreSSL on
OpenBSD.
2021-11-26 08:20:10 +01:00
Mark Andrews
08f1cba096 Do not convert ISC_R_NOSPACE to DNS_R_SERVFAIL too early
The parsing loop needs to process ISC_R_NOSPACE to properly
size the buffer.  If result is still ISC_R_NOSPACE at the end
of the parsing loop set result to DNS_R_SERVFAIL.
2021-11-25 19:48:20 +00:00
Michal Nowak
d09447287f Fix "array subscript is of type 'char'" on NetBSD 9
In file included from rdata.c:602:
    In file included from ./code.h:88:
    ./rdata/in_1/svcb_64.c:259:9: warning: array subscript is of type 'char' [-Wchar-subscripts]
                            if (!isdigit(*region->base)) {
                                 ^~~~~~~~~~~~~~~~~~~~~~
    /usr/include/sys/ctype_inline.h:51:44: note: expanded from macro 'isdigit'
    #define isdigit(c)      ((int)((_ctype_tab_ + 1)[(c)] & _CTYPE_D))
                                                    ^~~~
2021-11-25 18:15:18 +01:00
Mark Andrews
1092d8e25a use .s_addr to handle potential union in struct in_addr 2021-11-25 12:33:04 +00:00
Artem Boldariev
6c8a97c78f Fix a crash on unexpected incoming DNS message during XoT xfer
This commit fixes a peculiar corner case in the client-side DoT code
because of which a crash could occur during a zone transfer. A junk
DNS message should be sent at the end of a zone transfer via TLS to
trigger the crash (abort).

This commit, hopefully, fixes that.

Also, this commit adds similar changes to the TCP DNS code, as it
shares the same origin and most of the logic.
2021-11-24 11:18:36 +02:00
Michał Kępień
8f8a69aa0a Fix handling of mismatched responses past timeout
When a UDP dispatch receives a mismatched response, it checks whether
there is still enough time to wait for the correct one to arrive before
the timeout fires.  If there is not, the result code is set to
ISC_R_TIMEDOUT, but it is not subsequently used anywhere as 'response'
is set to NULL a few lines earlier.  This results in the higher-level
read callback (resquery_response() in case of resolver code) not being
called.  However, shortly afterwards, a few levels up the call chain,
isc__nm_udp_read_cb() calls isc__nmsocket_timer_stop() on the dispatch
socket, effectively disabling read timeout handling for that socket.
Combined with the fact that reading is not restarted in such a case
(e.g. by calling dispatch_getnext() from udp_recv()), this leads to the
higher-level query structure remaining referenced indefinitely because
the dispatch socket it uses will neither be read from nor closed due to
a timeout.  This in turn causes fetch contexts to linger around
indefinitely, which in turn i.a. prevents certain cache nodes (those
containing rdatasets used by fetch contexts, like fctx->nameservers)
from being cleaned.

Fix by making sure the higher-level callback does get invoked with the
ISC_R_TIMEDOUT result code when udp_recv() determines there is no more
time left to receive the correct UDP response before the timeout fires.
This allows the higher-level callback to clean things up, preventing the
reference leak described above.
2021-11-23 15:35:39 +01:00
Aram Sargsyan
43ac2cd229 Fix catalog zone reconfiguration crash
The following scenario triggers a "named" crash:

1. Configure a catalog zone.
2. Start "named".
3. Comment out the "catalog-zone" clause.
4. Run `rndc reconfig`.
5. Uncomment the "catalog-zone" clause.
6. Run `rndc reconfig` again.

Implement the required cleanup of the in-memory catalog zone during
the first `rndc reconfig`, so that the second `rndc reconfig` could
find it in an expected state.
2021-11-23 11:39:37 +00:00
Mark Andrews
34f3240622 Reject too long ECDSA public keys
opensslecdsa_fromdns() already rejects too short ECDSA public keys.
Make it also reject too long ones.  Remove an assignment made redundant
by this change.
2021-11-23 08:44:47 +11:00
Michał Kępień
a9ab2bf60b Pass key length to raw_key_to_ossl() by value
As raw_key_to_ossl() no longer stores anything at the pointer passed to
it in the 'key_len' parameter, change the type of the latter to size_t.
2021-11-23 08:44:47 +11:00
Michał Kępień
a482a6b204 Fix parsing ECDSA keys
raw_key_to_ossl() assumes fixed ECDSA private key sizes (32 bytes for
ECDSAP256SHA256, 48 bytes for ECDSAP384SHA384).  Meanwhile, in rare
cases, ECDSAP256SHA256 private keys are representable in 31 bytes or
less (similarly for ECDSAP384SHA384) and that is how they are then
stored in the "PrivateKey" field of the key file.  Nevertheless,
raw_key_to_ossl() always calls BN_bin2bn() with a fixed length argument,
which in the cases mentioned above leads to erroneously interpreting
uninitialized memory as a part of the private key.  This results in the
latter being malformed and broken signatures being generated.  Address
by using the key length provided by the caller rather than a fixed one.
Apply the same change to public key parsing code for consistency, adding
an INSIST() to prevent buffer overruns.
2021-11-23 08:44:47 +11:00
Evan Hunt
326a4fc13b fix a use-after-free in resolver
when processing a mismatched response, we call dns_dispatch_getnext().
If that fails, for example because of a timeout, fctx_done() is called,
which cancels all queries. This triggers a crash afterward when
fctx_cancelquery() is called, and is unnecessary since fctx_done()
would have been called later anyway.
2021-11-22 11:35:34 +01:00