In the cleanup code of fctx_query() function there is a code path
where 'query' is linked to 'fctx' and it is being destroyed.
Make sure that 'query' is unlinked before destroying it.
RPZ rewrites called dns_db_findext() without passing through the
client database options; as as result, if the client set CD=1,
DNS_DBFIND_PENDINGOK was not used as it should have been, and
cache lookups failed, resulting in failure of the rewrite.
The statschannel truncated test still terminates abruptly sometimes and
it doesn't return the answer for the first query. This might happen
when the second process_request() discovers there's not enough space
before the sending is complete and the connection is terminated before
the client gets the data.
Change the isc_http, so it pauses the reading when it receives the data
and resumes it only after the sending has completed or there's
incomplete request waiting for more data.
This makes the request processing slightly less efficient, but also less
taxing for the server, because previously all requests that has been
received via single TCP read would be processed in the loop and the
sends would be queued after the read callback has processed a full
buffer.
In non-developer build, a wrong condition prevented the
isc__tls_malloc_ex, isc__tls_realloc_ex and isc__tls_free_ex to be
defined. This was causing FTBFS on platforms with OpenSSL 1.0.2.
It was possible that accept callback can be called after listener
shutdown. In such a case the callback pointer equals NULL, leading to
segmentation fault. This commit fixes that.
This log happens when BIND checks the parental-agents if the DS has
been published. But if you don't have parental-agents set up, the list
of keys to check will be empty and the result will be ISC_R_NOTFOUND.
This is not an error, so change the log level to debug in this case.
Since we are using designated initializers, we were missing initializers
for ISC_LIST and ISC_LINK, add them, so you can do
*foo = (foo_t){ .list = ISC_LIST_INITIALIZER };
Instead of:
*foo = (foo_t){ 0 };
ISC_LIST_INIT(foo->list);
This commit introduces a primitive isc__nmsocket_stop() which performs
shutting down on a multilayered socket ensuring the proper order of
the operations.
The shared data within the socket object can be destroyed after the
call completed, as it is guaranteed to not be used from within the
context of other worker threads.
I.e. print the name of the function in BIND that called the system
function that returned an error. Since it was useful for pthreads
code, it seems worthwhile doing so everywhere.
Mostly generated automatically with the following semantic patch,
except where coccinelle was confused by #ifdef in lib/isc/net.c
@@ expression list args; @@
- UNEXPECTED_ERROR(__FILE__, __LINE__, args)
+ UNEXPECTED_ERROR(args)
@@ expression list args; @@
- FATAL_ERROR(__FILE__, __LINE__, args)
+ FATAL_ERROR(args)
The isccfg_duration_fromtext() function is truncating large numbers
to 32 bits instead of capping or rejecting them, i.e. 64424509445,
which is 0xf00000005, gets parsed as 32-bit value 5 (0x00000005).
Fail parsing a duration if any of its components is bigger than
32 bits. Using those kind of big numbers has no practical use case
for a duration.
The isccfg_duration_toseconds() function can overflow the 32 bit
seconds variable when calculating the duration from its component
parts.
To avoid that, use 64-bit calculation and return UINT32_MAX if the
calculated value is bigger than UINT32_MAX. Again, a number this big
has no practical use case anyway.
The buffer for the generated duration string is limited to 64 bytes,
which, in theory, is smaller than the longest possible generated
duration string.
Use 80 bytes instead, calculated by the '7 x (10 + 1) + 3' formula,
where '7' is the count of the duration's parts (year, month, etc.), '10'
is their maximum length when printed as a decimal number, '1' is their
indicator character (Y, M, etc.), and 3 is two more indicators (P and T)
and the terminating NUL character.
The cfg_print_duration() checks added previously in the 'duration_test'
unit test uncovered a bug in cfg_print_duration().
When calculating the current 'str' pointer of the generated text in the
buffer 'buf', it erroneously adds 1 byte to compensate for that part's
indicator character. For example, to add 12 minutes, it needs to add
2 + 1 = 3 characters, where 2 is the length of "12", and 1 is the length
of "M" (for minute). The mistake was that the length of the indicator
is already included in 'durationlen[i]', so there is no need to
calculate it again.
In the result of this mistake the current pointer can advance further
than needed and end up after the zero-byte instead of right on it, which
essentially cuts off any further generated text. For example, for a
5 minutes and 30 seconds duration, instead of having this:
'P', 'T', '5', 'M', '3', '0', 'S', '\0'
The function generates this:
'P', 'T', '5', 'M', '\0', '3', '0', 'S', '\0'
Fix the bug by adding to 'str' just 'durationlen[i]' instead of
'durationlen[i] + 1'.
The cfg_print_duration() function prints a ISO 8601 duration value
converted from an array of integers, where the parts of the date and
time are stored.
durationlen[6], which holds the "seconds" part of the duration, has
a special case in cfg_print_duration() to ensure that when there are
no values in the duration, the result still can be printed as "PT0S",
instead of just "P", so it can be a valid ISO 8601 duration value.
There is a logical error in one of the two special case code paths,
when it checks that no value from the "date" part is defined, and no
"hour" or "minute" from the "time" part are defined.
Because of the error, durationlen[6] can be used uninitialized, in
which case the second parameter passed to snprintf() (which is the
maximum allowed length) can contain a garbage value.
This can not be exploited because the buffer is still big enough to
hold the maximum possible amount of characters generated by the "%u%c"
format string.
Fix the logical bug, and initialize the 'durationlen' array to zeros
to be a little safer from other similar errors.
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.
During loop manager refactoring isc_nmsocket_set_tlsctx() was not
properly adapted. The function is expected to broadcast the new TLS
context for every worker, but this behaviour was accidentally broken.
Replace all uses of RUNTIME_CHECK() in lib/isc/include/isc/once.h with
PTHEADS_RUNTIME_CHECK(), in order to improve error reporting for any
once-related run-time failures (by augmenting error messages with
file/line/caller information and the error string corresponding to
errno).
Rewrite the isc_httpd to be more robust.
1. Replace the hand-crafted HTTP request parser with picohttpparser for
parsing the whole HTTP/1.0 and HTTP/1.1 requests. Limit the number
of allowed headers to 10 (arbitrary number).
2. Replace the hand-crafted URL parser with isc_url_parse for parsing
the URL from the HTTP request.
3. Increase the receive buffer to match the isc_netmgr buffers, so we
can at least receive two full isc_nm_read()s. This makes the
truncation processing much simpler.
4. Process the received buffer from single isc_nm_read() in a single
loop and schedule the sends to be independent of each other.
The first two changes makes the code simpler and rely on already
existing libraries that we already had (isc_url based on nodejs) or are
used elsewhere (picohttpparser).
The second two changes remove the artificial "truncation" limit on
parsing multiple request. Now only a request that has too many
headers (currently 10) or is too big (so, the receive buffer fills up
without reaching end of the request) will end the connection.
We can be benevolent here with the limites, because the statschannel
channel is by definition private and access must be allowed only to
administrators of the server. There are no timers, no rate-limiting, no
upper limit on the number of requests that can be served, etc.
PicoHTTPParser is a tiny, primitive, fast HTTP request/response parser.
Unlike most parsers, it is stateless and does not allocate memory by
itself. All it does is accept pointer to buffer and the output
structure, and setups the pointers in the latter to point at the
necessary portions of the buffer.
sizeof(dns_name_t) did not change but the boolean attributes are now
separated as one-bit structure members. This allows debuggers to
pretty-print dns_name_t attributes without any special hacks, plus we
got rid of manual bit manipulation code.
Originally RBT node stored three lowest bits from dns_name_t attributes.
This had a curious side-effect noticed by Tony Finch:
If you create an rbt node from a DYNAMIC name then the flag will be
propagated through dns_rbt_namefromnode() ... if you subsequently call
dns_name_free() it will try to isc_mem_put() a piece of an rbt node ...
but dns_name_free() REQUIRE()s that the name is dynamic so in the usual
case where rbt nodes are created from non-dynamic names, this kind of
code will fail an assertion.
This is a bug it dates back to june 1999 when NAMEATTR_DYNAMIC was
invented.
Apparently it does not happen often :-)
I'm planning to get rid of DNS_NAMEATTR_ definitions and bit operations,
so removal of this "three-bit-subset" assignment is a first step.
We can keep only the ABSOLUTE flag in RBT node and nothing else because
names attached to rbt nodes are always readonly: The internal node_name()
function always sets the NAMEATTR_READONLY when making a dns_name that
refers to the node's name, so the READONLY flag will be set in the name
returned by dns_rbt_namefromnode().
Co-authored-by: Tony Finch <fanf@isc.org>
The isc_nm_udpconnect() erroneously set the reuse port with
load-balancing on the outgoing connected UDP sockets. This socket
option makes only sense for the listening sockets. Don't set the
load-balancing reuse port option on the outgoing UDP sockets.
This commit fixes TLS DNS verification error message reporting which
we probably broke during one of the recent networking code
refactorings.
This prevent e.g. dig from producing useful error messages related to
TLS certificates verification.
Ensure that TLS error is empty before calling SSL_get_error() or doing
SSL I/O so that the result will not get affected by prior error
statuses.
In particular, the improper error handling led to intermittent unit
test failure and, thus, could be responsible for some of the system
test failures and other intermittent TLS-related issues.
See here for more details:
https://www.openssl.org/docs/man3.0/man3/SSL_get_error.html
In particular, it mentions the following:
> The current thread's error queue must be empty before the TLS/SSL
> I/O operation is attempted, or SSL_get_error() will not work
> reliably.
As we use the result of SSL_get_error() to decide on I/O operations,
we need to ensure that it works reliably by cleaning the error queue.
TLS DNS: empty error queue before attempting I/O
The check is left from when tcp_connect_direct() called isc__nm_socket()
and it was uncertain whether it had succeeded, but now isc__nm_socket()
is called before tcp_connect_direct(), so sock->fd cannot be -1.
*** CID 357292: (REVERSE_NEGATIVE)
/lib/isc/netmgr/tcp.c: 309 in isc_nm_tcpconnect()
303
304 atomic_store(&sock->active, true);
305
306 result = tcp_connect_direct(sock, req);
307 if (result != ISC_R_SUCCESS) {
308 atomic_store(&sock->active, false);
>>> CID 357292: (REVERSE_NEGATIVE)
>>> You might be using variable "sock->fd" before verifying that it is >= 0.
309 if (sock->fd != (uv_os_sock_t)(-1)) {
310 isc__nm_tcp_close(sock);
311 }
312 isc__nm_connectcb(sock, req, result, true);
313 }
314
Getting the recorded value of 'edns-udp-size' from the resolver requires
strong attach to the dns_view because we are accessing `view->resolver`.
This is not the case in places (f.e. dns_zone unit) where `.udpsize` is
accessed. By moving the .udpsize field from `struct dns_resolver` to
`struct dns_view`, we can access the value directly even with weakly
attached dns_view without the need to lock the view because `.udpsize`
can be accessed after the dns_view object has been shut down.
The dns_view implements weak and strong reference counting. When strong
reference counting reaches zero, the adb, ntatable and resolver objects
are shut down and detached.
In dns_zone and dns_nta the dns_view was weakly attached, but the
view->resolver reference was accessed directly leading to dereferencing
the NULL pointer.
Add dns_view_getresolver() method which attaches to view->resolver
object under the lock (if it still exists) ensuring the dns_resolver
will be kept referenced until not needed.
The value of `sign_bit` is platform-dependent but constant at compile
time. Use a cast to convert the boolean `sign_bit` to 0 or 1 instead of
ternary `?:` because one branch of the conditional is dead code. (We
could leave out the cast to `size_t` but our style prefers to handle
booleans more explicitly, hence the `?:` that caused the issue.)
*** CID 358310: Possible Control flow issues (DEADCODE)
/lib/isc/resource.c: 118 in isc_resource_setlimit()
112 * rlim_t, and whether rlim_t has a sign bit.
113 */
114 isc_resourcevalue_t rlim_max = UINT64_MAX;
115 size_t wider = sizeof(rlim_max) - sizeof(rlim_t);
116 bool sign_bit = (double)(rlim_t)-1 < 0;
117
>>> CID 358310: Possible Control flow issues (DEADCODE)
>>> Execution cannot reach the expression "1" inside this statement: "rlim_max >>= 8UL * wider + ...".
118 rlim_max >>= CHAR_BIT * wider + (sign_bit ? 1 : 0);
119 rlim_value = ISC_MIN(value, rlim_max);
120 }
121
122 rl.rlim_cur = rl.rlim_max = rlim_value;
123 unixresult = setrlimit(unixresource, &rl);
While refactoring the isc_mem_getx(...) usage, couple places were
identified where the memory was resized manually. Use the
isc_mem_reget(...) that was introduced in [GL !5440] to resize the
arrays via function rather than a custom code.
In several places, the structures were cleaned with memset(...)) and
thus the semantic patch converted the isc_mem_get(...) to
isc_mem_getx(..., ISC_MEM_ZERO). Use the designated initializer to
initialized the structures instead of zeroing the memory with
ISC_MEM_ZERO flag as this better matches the intended purpose.
Add new semantic patch to replace the straightfoward uses of:
ptr = isc_mem_{get,allocate}(..., size);
memset(ptr, 0, size);
with the new API call:
ptr = isc_mem_{get,allocate}x(..., size, ISC_MEM_ZERO);
Previously, the isc_mem_get_aligned() and friends took alignment size as
one of the arguments. Replace the specific function with more generic
extended variant that now accepts ISC_MEM_ALIGN(alignment) for aligned
allocations and ISC_MEM_ZERO for allocations that zeroes
the (re-)allocated memory before returning the pointer to the caller.
The previous commit failed some tests because we expect that if a
fetch fails and we have stale candidates in cache, the
stale-refresh-time window is started. This means that if we hit a stale
entry in cache and answering stale data is allowed, we don't bother
resolving it again for as long we are within the stale-refresh-time
window.
This is useful for two reasons:
- If we failed to fetch the RRset that we are looking for, we are not
hammering the authoritative servers.
- Successor clients don't need to wait for stale-answer-client-timeout
to get their DNS response, only the first one to query will take
the latency penalty.
The latter is not useful when stale-answer-client-timeout is 0 though.
So this exception code only to make sure we don't try to refresh the
RRset again if it failed to do so recently.
Refreshing a stale RRset is similar to prefetching an RRset, so
reuse the existing code. When refreshing an RRset we need to clear
all db options related to serve-stale so that stale RRsets in cache
are ignored during the refresh.
We no longer need to set the "nodetach" flag, because the refresh
fetch is now a "fetch and forget". So we can detach from the client
in the query_send().
This code will break some serve-stale test cases, this will be fixed
in the successor commit.
TODO: add explanation why the serve-stale test cases fail.
Formerly, the isc_hash32() would have to change the key in a local copy
to make it case insensitive. Change the isc_siphash24() and
isc_halfsiphash24() functions to lowercase the input directly when
reading it from the memory and converting the uint8_t * array to
64-bit (respectively 32-bit numbers).
dohpath is specfied in draft-ietf-add-svcb-dns and has a value
of 7. It must be a relative path (start with a /), be encoded
as UTF8 and contain the variable dns ({?dns}).
On systems with signed rlim_t the old code calculated its maximum
value by shifting 1 into the sign bit, which is undefined behaviour.
Avoid the bug by using an unsigned shift.
The dns__nta_shutdown() could be run from different threads and it was
accessing nta->timer unlocked. Don't check and stop the timer from
dns__nta_shutdown() directly, but leave it for the async callback.
Because the dns_zonemgr_create() was run before the loopmgr was started,
the isc_ratelimiter API was more complicated that it had to be. Move
the dns_zonemgr_create() to run_server() task which is run on the main
loop, and simplify the isc_ratelimiter API implementation.
The isc_timer is now created in the isc_ratelimiter_create() and
starting the timer is now separate async task as is destroying the timer
in case it's not launched from the loop it was created on. The
ratelimiter tick now doesn't have to create and destroy timer logic and
just stops the timer when there's no more work to do.
This should also solve all the races that were causing the
isc_ratelimiter to be left dangling because the timer was stopped before
the last reference would be detached.
Unlike standard free(), isc_mem_free() is not a no-op when passed a
NULL pointer. For size accounting purposes it calls sallocx(), which
crashes when passed a NULL pointer. To get more helpful diagnostics,
REQUIRE() that the pointer is not NULL so that when the programmer
makes a mistake they get a backtrace that shows what went wrong.
The isc__nm_udp_send() callback would be called synchronously when
shutting down or when the socket has been closed. This could lead to
double locking in the calling code and thus those callbacks needs to be
called asynchronously.
Now that the 'dns_request' supports using TLS transport, implement
dynamic update forwarding using DoT when the primary server is
configured to use a TLS transport.
Previously, when using such configuration, the dynamic update forwarding
feature was broken.
