The DNS Flag Day 2020 aims to remove the IP fragmentation problem from
the UDP DNS communication. In this commit, we implement the minimal
required changes by changing the defaults for `edns-udp-size`,
`max-udp-size` and `nocookie-udp-size` to `1232` (the value picked by
DNS Flag Day 2020).
(cherry picked from commit bb990030d3)
The SO_REUSEADDR, SO_REUSEPORT and SO_REUSEPORT_LB has different meaning
on different platform. In this commit, we split the function to set the
reuse of address/port and setting the load-balancing into separate
functions.
The libuv library already have multiplatform support for setting
SO_REUSEADDR and SO_REUSEPORT that allows binding to the same address
and port, but unfortunately, when used after the load-balancing socket
options have been already set, it overrides the previous setting, so we
need our own helper function to enable the SO_REUSEADDR/SO_REUSEPORT
first and then enable the load-balancing socket option.
(cherry picked from commit fd975a551d)
On POSIX based systems both uv_os_sock_t and uv_os_fd_t are both typedef
to int. That's not true on Windows, where uv_os_sock_t is SOCKET and
uv_os_fd_t is HANDLE and they differ in level of indirection.
(cherry picked from commit acb6ad9e3c)
The isc__nm_socket_freebind() has been refactored to match other
isc__nm_socket_...() helper functions and take uv_os_fd_t and
sa_family_t as function arguments.
(cherry picked from commit 9dc01a636b)
While working on 'rndc dnssec -rollover' I noticed the following
(small) issues:
- The key files where updated with hints set to "-when" and that
should always be "now.
- The kasp system test did not properly update the test number when
calling 'rndc dnssec -checkds' (and ensuring that works).
- There was a missing ']' in the rndc.c help output.
(cherry picked from commit edc53fc416)
Add to the keymgr a function that will schedule a rollover. This
basically means setting the time when the key needs to retire,
and updating the key lifetime, then update the state file. The next
time that named runs the keymgr the new lifetime will be taken into
account.
(cherry picked from commit df8276aef0)
After backporting #1870 to 9.11-S I saw that the condition check there
is different than in the main branch. In 9.11-S "stale" can mean
stale and serve-stale, or not active (awaiting cleanup). In 9.16 and
later versions, "stale" is stale and serve-stale, and "ancient" means
not active (awaiting cleanup). An "ancient" RRset is one that is not
active (TTL expired) and is not eligble for serve-stale.
Update the condition for rndc dumpdb -expired to closer match what is
in 9.11-S.
(cherry picked from commit 5614454c3b)
The kasp code had bad implicit size values for the cryptographic
algorithms Ed25519 and Ed448. When creating keys they would never
match the dnssec-policy, leading to new attempts to create keys.
These algorithms were previously not yet added to the system tests,
due to lack of availability on some systems.
(cherry picked from commit 0e207392ec)
named-checkconf treats the following configuration as valid:
options {
rrset-order {
order none;
};
};
Yet, the above configuration causes named to crash on startup with:
order.c:74: REQUIRE(mode == 0x00000800 || mode == 0x00000400 || mode == 0x00800000) failed, back trace
Add DNS_RDATASETATTR_NONE to the list of RRset ordering modes accepted
by dns_order_add() to allow "order none" to be used in "rrset-order"
rules. This both prevents the aforementioned crashes and addresses the
discrepancy between named-checkconf and named.
(cherry picked from commit dbcf683c1a)
The clang 12 has a new warning that warns when using multi-line strings
in the string arrays, f.e.:
{ "aa",
"b"
"b",
"cc" }
would generate warning like this:
private_test.c:162:7: error: suspicious concatenation of string literals in an array initialization; did you mean to separate the elements with a comma? [-Werror,-Wstring-concatenation]
"33333/RSASHA1" };
^
private_test.c:161:7: note: place parentheses around the string literal to silence warning
"Done removing signatures for key "
^
private_test.c:197:7: error: suspicious concatenation of string literals in an array initialization; did you mean to separate the elements with a comma? [-Werror,-Wstring-concatenation]
"NSEC chain",
^
private_test.c:196:7: note: place parentheses around the string literal to silence warning
"Removing NSEC3 chain 1 0 30 DEAF / creating "
^
2 errors generated.
(cherry picked from commit 7b07f22969)
As the query_prefetch() or query_rpzfetch() could be called during
"regular" fetch, we need to introduce separate storage for attaching
the nmhandle during prefetching the records. The query_prefetch()
and query_rpzfetch() are guarded for re-entrance by .query.prefetch
member of ns_client_t, so we can reuse the same .prefetchhandle for
both.
(cherry picked from commit d4976e0ebe)
The isc_nm_pause(), isc_nm_resume() and finishing the nm_thread() from
nm_destroy() has been refactored, so all use the netievents instead of
directly touching the worker structure members. This allows us to
remove most of the locking as the .paused and .finished members are
always accessed from the matching nm_thread.
When shutting down the nm_thread(), instead of issuing uv_stop(), we
just shutdown the .async handler, so all uv_loop_t events are properly
finished first and uv_run() ends gracefully with no outstanding active
handles in the loop.
(cherry picked from commit e5ab137ba3)
If NETMGR_TRACE is defined, we now maintain a list of active sockets
in the netmgr object and a list of active handles in each socket
object; by walking the list and printing `backtrace` in a debugger
we can see where they were created, to assist in in debugging of
reference counting errors.
On shutdown, if netmgr finds there are still active sockets after
waiting, isc__nm_dump_active() will be called to log the list of
active sockets and their underlying handles, along with some details
about them.
(cherry picked from commit 00e04a86c8)
if more than 10 seconds pass while we wait for netmgr events to
finish running on shutdown, something is almost certainly wrong
and we should assert and crash.
(cherry picked from commit 2f2d60a989)
Attaching and detaching handle pointers will make it easier to
determine where and why reference counting errors have occurred.
A handle needs to be referenced more than once when multiple
asynchronous operations are in flight, so callers must now maintain
multiple handle pointers for each pending operation. For example,
ns_client objects now contain:
- reqhandle: held while waiting for a request callback (query,
notify, update)
- sendhandle: held while waiting for a send callback
- fetchhandle: held while waiting for a recursive fetch to
complete
- updatehandle: held while waiting for an update-forwarding
task to complete
(cherry picked from commit 57b4dde974)
- rename isc_nmsocket_t->tcphandle to statichandle
- cancelread functions now take handles instead of sockets
- add a 'client' flag in socket objects, currently unused, to
indicate whether it is to be used as a client or server socket
(cherry picked from commit 7eb4564895)
Each worker has a receive buffer with space for 20 DNS messages of up
to 2^16 bytes each, and the allocator function passed to uv_read_start()
or uv_udp_recv_start() will reserve a portion of it for use by sockets.
UDP can use recvmmsg() and so it needs that entire space, but TCP reads
one message at a time.
This commit introduces separate allocator functions for TCP and UDP
setting different buffer size limits, so that libuv will provide the
correct buffer sizes to each of them.
(cherry picked from commit 38264b6a4d)
When a new IPv6 interface/address appears it's first in a tentative
state - in which we cannot bind to it, yet it's already being reported
by the route socket. Because of that BIND9 is unable to listen on any
newly detected IPv6 addresses. Fix it by setting IP_FREEBIND option (or
equivalent option on other OSes) and then retrying bind() call.
(cherry picked from commit a0f7d28967)
by having these functions act on netmgr handles instead of socket
objects, they can be used in callback functions outside the netgmr.
(cherry picked from commit 55896df79d)
We erroneously tried to destroy a socket after issuing
isc__nm_tcp{,dns}_close. Under some (race) circumstances we could get
nm_socket_cleanup to be called twice for the same socket, causing an
access to a dead memory.
(cherry picked from commit 233f134a4f)
There's a possibility of race in isc__nm_tcpconnect if the asynchronous
connect operation finishes with all the callbacks before we exit the
isc__nm_tcpconnect itself we might access an already freed memory.
Fix it by creating an additional reference to the socket freed at the
end of isc__nm_tcpconnect.
(cherry picked from commit 896db0f419)
the blackhole ACL was accidentally disabled with respect to client
queries during the netmgr conversion.
in order to make this work for TCP, it was necessary to add a return
code to the accept callback functions passed to isc_nm_listentcp() and
isc_nm_listentcpdns().
(cherry picked from commit 23c7373d68)
isc__nm_tcpdns_send() was not asynchronous and accessed socket
internal fields in an unsafe manner, which could lead to a race
condition and subsequent crash. Fix it by moving tcpdns processing
to a proper netmgr thread.
(cherry picked from commit 591b79b597)
We need to mark the socket as inactive early (and synchronously)
in the stoplistening process; otherwise we might destroy the
callback argument before we actually stop listening, and call
the callback on bad memory.
(cherry picked from commit 1cf65cd882)
this prevents a crash when some non-netmgr thread, such as a
recursive lookup, times out after the TCP socket is already
disconnected.
(cherry picked from commit 3704c4fff2)
this will allow recv event handlers to distinguish between cases
in which the region is NULL because of error, shutdown, or cancelation.
(cherry picked from commit 75c985c07f)
The isc_nm_cancelread() function cancels reading on a connected
socket and calls its read callback function with a 'result'
parameter of ISC_R_CANCELED.
(cherry picked from commit 5191ec8f86)
when isc_nm_destroy() is called, there's a loop that waits for
other references to be detached, pausing and unpausing the netmgr
to ensure that all the workers' events are run, followed by a
1-second sleep. this caused a delay on shutdown which will be
noticeable when netmgr is used in tools other than named itself,
so the delay has now been reduced to a hundredth of a second.
(cherry picked from commit 870204fe47)
the isc_nm_tcpconnect() function establishes a client connection via
TCP. once the connection is esablished, a callback function will be
called with a newly created network manager handle.
(cherry picked from commit abbb79f9d1)
A TCPDNS socket creates a handle for each complete DNS message.
Previously, when all the handles were disconnected, the socket
would be closed, but the wrapped TCP socket might still have
more to read.
Now, when a connection is established, the TCPDNS socket creates
a reference to itself by attaching itself to sock->self. This
reference isn't cleared until the connection is closed via
EOF, timeout, or server shutdown. This allows the socket to remain
open even when there are no active handles for it.
(cherry picked from commit cd79b49538)
- isc__nmhandle_get() now attaches to the sock in the nmhandle object.
the caller is responsible for dereferencing the original socket
pointer when necessary.
- tcpdns listener sockets attach sock->outer to the outer tcp listener
socket. tcpdns connected sockets attach sock->outerhandle to the handle
for the tcp connected socket.
- only listener sockets need to be attached/detached directly. connected
sockets should only be accessed and reference-counted via their
associated handles.
(cherry picked from commit 5ea26ee1f1)
there is no need for a caller to reference-count socket objects.
they need tto be able tto close listener sockets (i.e., those
returned by isc_nm_listen{udp,tcp,tcpdns}), and an isc_nmsocket_close()
function has been added for that. other sockets are only accessed via
handles.
(cherry picked from commit 9e740cad21)
The following reverted changes will be picked again as part of the
netmgr sync with main branch.
Revert "Merge branch '1996-confidential-issue-v9_16' into 'security-v9_16'"
This reverts commit e160b1509f, reversing
changes made to c01e643715.
Revert "Merge branch '2038-use-freebind-when-bind-fails-v9_16' into 'v9_16'"
This reverts commit 5f8ecfb918, reversing
changes made to 23021385d5.
Revert "Merge branch '1936-blackhole-fix-v9_16' into 'v9_16'"
This reverts commit f20bc90a72, reversing
changes made to 490016ebf1.
Revert "Merge branch '1938-fix-udp-race' into 'v9_16'"
This reverts commit 0a6c7ab2a9, reversing
changes made to 4ea84740e6.
Revert "Merge branch '1947-fix-tcpdns-race' into 'v9_16'"
This reverts commit 4ea84740e6, reversing
changes made to d761cd576b.
The dns_message_create() function cannot soft fail (as all memory
allocations either succeed or cause abort), so we change the function to
return void and cleanup the calls.
(cherry picked from commit 33eefe9f85)
This commit fix the problems that arose when moving the dns_message_t
object from fetchctx_t to the query structure.
Since the lifetime of query objects are different than that of a
fetchctx and the dns_message_t object held by the query may be being
used by some external module, e.g. validator, even after the query
may have been destroyed, propery handling of the references to the
message were added in this commit to avoid accessing an already
destroyed object.
Specifically, in rctx_done(), a reference to the message is attached
at the beginning of the function and detached at the end, since a
possible call to fctx_cancelquery() would release the dns_message_t
object, and in the next lines of code a call to rctx_nextserver()
or rctx_chaseds() would require a valid pointer to the same object.
In valcreate() a new reference is attached to the message object,
this ensures that if the corresponding query object is destroyed
before the validator attempts to access it, no invalid pointer
access occurs.
In validated() we have to attach a new reference to the message,
since we destroy the validator object at the beginning of the
function, and we need access to the message in the next lines of
the same function.
rctx_nextserver() and rctx_chaseds() functions were adapted to
receive a new parameter of dns_message_t* type, this was so they
could receive a valid reference to a dns_message_t since using the
response context respctx_t to access the message through
rctx->query->rmessage could lead to an already released reference
due to the query being canceled.
(cherry picked from commit cde6227a68)
The assertion failure REQUIRE(msg->state == DNS_SECTION_ANY), caused
by calling dns_message_setclass within function resquery_response()
in resolver.c, was happening due to wrong management of dns message_t
objects used to process responses to the queries issued by the
resolver.
Before the fix, a resolver's fetch context (fetchctx_t) would hold
a pointer to the message, this same reference would then be used
over all the attempts to resolve the query, trying next server,
etc... for this to work the message object would have it's state
reset between each iteration, marking it as ready for a new processing.
The problem arose in a scenario with many different forwarders
configured, managing the state of the dns_message_t object was
lacking better synchronization, which have led it to a invalid
dns_message_t state in resquery_response().
Instead of adding unnecessarily complex code to synchronize the
object, the dns_message_t object was moved from fetchctx_t structure
to the query structure, where it better belongs to, since each query
will produce a response, this way whenever a new query is created
an associated dns_messate_t is also created.
This commit deals mainly with moving the dns_message_t object from
fetchctx_t to the query structure.
(cherry picked from commit 02f9e125c1)
Mark Andrews
Ondřej SurýandOndřej Surý
Matthijs Mekking
Michał Kępień
Witold KręcickiandOndřej Surý
Evan HuntandOndřej Surý
Diego FronzaandMark Andrews