this supercedes the experiment in commit eab6c2bff
("attach to nmhandle during zerottl refetch"), and ensures that
the client can't be reset before fetch_callback() is reached.
- when we attempt to shut down a parent socket, but its children
still have active handles, the destruction is delayed, and previously
it was never resumed. now, when the last handle for a child socket is
detached, we check again whether the parent can be destroyed.
- the netmgr is not shut down until all references to it are detached.
- document functions in netmgr.h and netmgr-int.h
- combine identical callback typedefs into one
- remove functions that were never called
- make functions called in only one file static
- rename isc__nm_handle_*() functions to isc__nm_async_*() to avoid
confusion with the isc__nmhandle type.
- clean up isc_nmevent structures - make generic types and just typedef to them
- fix atomic clang warnings in astack
- add pause/resume read for TCP
- add sequential (not-pipelining) support for TCPDNS
- keep peer address in the socket for TCP connections, it's constant for a socket
this delays the destruction of the client object until after the
prefetch is finished.
also added some missing CTRACE logging in query.c, in the process of
diagnosing this error.
- add reference counters to manager; all client objects attach and
detach from the manager
- ensure that when a client object is detached, if references have gone
to zero, the associated nmhandle object is detached. this should
trigger the freeing of both the nmhandle object and the client object
- as client objects are now allocated along with network manager clients
and will be accounted for by the network manager, there's no longer a
need to call exit_check(). its functions are now replaced by the
nmhandle reset and put callbacks.
- there is no need to keep a 'clients' list in ns_clientmgr()
- (however, TODO, the client manager should now be reference counted)
- added some logging to show when clients are allocated, reset, or freed
- ns_client_next() has no remaining function except to log the reason
for a failure. its name has therefore been changed to ns_client_drop().
- Start netmgr with named, shutdown at the end
- udplistener in interfacemgr uses netmgr
- use per-client buffer for udp send
- first steps at making ns_client_request use netmgr for UDP
- uncrustify
- Make interfacemgr and interface references isc_refcount_t instead of locked ints
- Use clock_gettime instead of gettimeofday
- Cleanup get_client, use one interface for clientmgr instead of attaching it to each client
- 'extra' field at the end of handle - for client data
- clientmgr has a taskpool, clients attach to it
- TCP support
This commit changes the BIND cookie algorithms to match
draft-sury-toorop-dnsop-server-cookies-00. Namely, it changes the Client Cookie
algorithm to use SipHash 2-4, adds the new Server Cookie algorithm using SipHash
2-4, and changes the default for the Server Cookie algorithm to be siphash24.
Add siphash24 cookie algorithm, and make it keep legacy aes as
- if the TCP quota has been exceeded but there are no clients listening
for new connections on the interface, we can now force attachment to the
quota using isc_quota_force(), instead of carrying on with the quota not
attached.
- the TCP client quota is now referenced via a reference-counted
'ns_tcpconn' object, one of which is created whenever a client begins
listening for new connections, and attached to by members of that
client's pipeline group. when the last reference to the tcpconn
object is detached, it is freed and the TCP quota slot is released.
- reduce code duplication by adding mark_tcp_active() function
- convert counters to stdatomic
(cherry picked from commit a8dd133d270873b736c1be9bf50ebaa074f5b38f)
(cherry picked from commit 4a8fc979c4)
- ensure that tcpactive is cleaned up correctly when accept() fails.
- set 'client->tcpattached' when the client is attached to the tcpquota.
carry this value on to new clients sharing the same pipeline group.
don't call isc_quota_detach() on the tcpquota unless tcpattached is
set. this way clients that were allowed to accept TCP connections
despite being over quota (and therefore, were never attached to the
quota) will not inadvertently detach from it and mess up the
accounting.
- simplify the code for tcpquota disconnection by using a new function
tcpquota_disconnect().
- before deciding whether to reject a new connection due to quota
exhaustion, check to see whether there are at least two active
clients. previously, this was "at least one", but that could be
insufficient if there was one other client in READING state (waiting
for messages on an open connection) but none in READY (listening
for new connections).
- before deciding whether a TCP client object can to go inactive, we
must ensure there are enough other clients to maintain service
afterward -- both accepting new connections and reading/processing new
queries. A TCP client can't shut down unless at least one
client is accepting new connections and (in the case of pipelined
clients) at least one additional client is waiting to read.
(cherry picked from commit 427a2fb4d17bc04ca3262f58a9dcf5c93fc6d33e)
(cherry picked from commit 0896841272)
Track pipeline groups using a shared reference counter
instead of a linked list.
(cherry picked from commit 31f392db20207a1b05d6286c3c56f76c8d69e574)
(cherry picked from commit 2211120222)
the TCP client quota could still be ineffective under some
circumstances. this change:
- improves quota accounting to ensure that TCP clients are
properly limited, while still guaranteeing that at least one client
is always available to serve TCP connections on each interface.
- uses more descriptive names and removes one (ntcptarget) that
was no longer needed
- adds comments
(cherry picked from commit 9e74969f85329fe26df2fad390468715215e2edd)
(cherry picked from commit d7e84cee0b)
- named could return FORMERR if parsing iterative responses
ended with a result code such as DNS_R_OPTERR. instead of
computing a response code based on the result, in this case
we now just force the response to be SERVFAIL.
Implement a helper function which, given an input string:
- copies it verbatim if it contains at least one path separator,
- prepends the named plugin installation directory to it otherwise.
This function will allow configuration parsing code to conveniently
determine the full path to a plugin module given either a path or a
filename.
While other, simpler ways exist for making sure filenames passed to
dlopen() cause the latter to look for shared objects in a specific
directory, they are very platform-specific. Using full paths is thus
likely the most portable and reliable solution.
Also added unit tests for ns_plugin_expandpath() to ensure it behaves
as expected for absolute paths, relative paths, and filenames, for
various target buffer sizes.
(Note: plugins share a directory with named on Windows; there is no
default plugin path. Therefore the source path is copied to the
destination path with no modification.)
- "hook" is now used only for hook points and hook actions
- the "hook" statement in named.conf is now "plugin"
- ns_module and ns_modlist are now ns_plugin and ns_plugins
- ns_module_load is renamed ns_plugin_register
- the mandatory functions in plugin modules (hook_register,
hook_check, hook_version, hook_destroy) have been renamed
- use a per-view module list instead of global hook_modules
- create an 'instance' pointer when registering modules, store it in
the module structure, and use it as action_data when calling
hook functions - this enables multiple module instances to be set
up in parallel
- also some nomenclature changes and cleanup
- added some hook points that will be needed for a dns64 module later
- moved some code from the beginning of query_respond() to
the end of query_prepresponse(); this has no effect on functionality
but means we can have a hook point at the top of query_respond(),
which seems nicer
- compressed duplicated code into query_zerottl_refetch() function
- added a qctx->answered flag so that a module can prevent
query_addrrset() from being called from query_respond() when
it's already been called from the module.
- this is necessary because adding the same hook to multiple views
causes the ISC_LIST link value to become inconsistent; it isn't
noticeable when only one hook action is ever registered at a
given hook point, but it will break things when there are two.
- eliminate qctx->hookdata and client->hookflags.
- use a memory pool to allocate data blobs in the filter-aaaa module,
and associate them with the client address in a hash table
- instead of detaching the client in query_done(), mark it for deletion
and then call ns_client_detach() from qctx_destroy(); this ensures
that it will still exist when the QCTX_DESTROYED hook point is
reached.
- use a get_hooktab() function to determine the hook table.
- PROCESS_HOOK now jumps to a cleanup tag on failure
- add PROCESS_ALL_HOOKS in query.c, to run all hook functions at
a specified hook point without stopping. this is to be used for
intiialization and destruction functions that must run in every
module.
- 'result' is set in PROCESS_HOOK only when a hook function
interrupts processing.
- revised terminology: a "callback" is now a "hook action"
- remove unused NS_PROCESS_HOOK and NS_PROCESS_HOOK_VOID macros.
- added a 'hookdata' array to qctx to store pointers to up to
16 blobs of data which are allocated by modules as needed.
each module is assigned an ID number as it's loaded, and this
is the index into the hook data array. this is to be used for
holding persistent state between calls to a hook module for a
specific query.
- instead of using qctx->filter_aaaa, we now use qctx->hookdata.
(this was the last piece of filter-aaaa specific code outside the
module.)
- added hook points for qctx initialization and destruction. we get
a filter-aaaa data pointer from the mempool when initializing and
store it in the qctx->hookdata table; return to to the mempool
when destroying the qctx.
- link the view to the qctx so that detaching the client doesn't cause
hooks to fail
- added a qctx_destroy() function which must be called after qctx_init;
this calls the QCTX_DESTROY hook and detaches the view
- general cleanup and comments
- make some cfg-parsing functions global so they can be run
from filter-aaaa.so
- add filter-aaaa options to the hook module's parser
- mark filter-aaaa options in named.conf as obsolete, remove
from named and checkconf, and update the filter-aaaa test not to
use checkconf anymore
- remove filter-aaaa-related struct members from dns_view
- allow multiple "hook" statements at global or view level
- add "optional bracketed text" type for optional parameter list
- load hook module from specified path rather than hardcoded path
- add a hooktable pointer (and a callback for freeing it) to the
view structure
- change the hooktable functions so they no longer update ns__hook_table
by default, and modify PROCESS_HOOK so it uses the view hooktable, if
set, rather than ns__hook_table. (ns__hook_table is retained for
use by unit tests.)
- update the filter-aaaa system test to load filter-aaaa.so
- add a prereq script to check for dlopen support before running
the filter-aaaa system test
not yet done:
- configuration parameters are not being passed to the filter-aaaa
module; the filter-aaaa ACL and filter-aaaa-on-{v4,v6} settings are
still stored in dns_view
- temporary kluge! in this version, for testing purposes,
named always searches for a filter-aaaa module at /tmp/filter-aaaa.so.
this enables the filter-aaaa system test to run even though the
code to configure hooks in named.conf hasn't been written yet.
- filter-aaaa-on-v4, filter-aaaa-on-v6 and the filter-aaaa ACL are
still configured in the view as they were before, not in the hook.
- these formerly static helper functions have been moved into client.c
and made external so that they can be used in hook modules as well as
internally in libns: query_newrdataset, query_putrdataset,
query_newnamebuf, query_newname, query_getnamebuf, query_keepname,
query_releasename, query_newdbversion, query_findversion
- made query_recurse() and query_done() into public functions
ns_query_recurse() and ns_query_done() so they can be called from
modules.
- the goal of this change is for AAAA filtering to be fully contained
in the query logic, and implemented at discrete points that can be
replaced with hook callouts later on.
- the new code may be slightly less efficient than the old filter-aaaa
implementation, but maximum efficiency was never a priority for AAAA
filtering anyway.
- we now use the rdataset RENDERED attribute to indicate that an AAAA
rdataset should not be included when rendering the message. (this
flag was originally meant to indicate that an rdataset has already
been rendered and should not be repeated, but it can also be used to
prevent rendering in the first place.)
- the DNS_MESSAGERENDER_FILTER_AAAA, NS_CLIENTATTR_FILTER_AAAA,
and DNS_RDATASETGLUE_FILTERAAAA flags are all now unnecessary and
have been removed.
- the purpose of this change is allow for more well-defined hook points
to be available in the query processing logic. some functions that
formerly didn't have access to 'qctx' do now; this is needed because
'qctx' is what gets passed when calling a hook function.
- query_addrdataset() has been broken up into three separate functions
since it used to do three unrelated things, and what was formerly
query_addadditional() has been renamed query_additional_cb() for
clarity.
- client->filter_aaaa is now qctx->filter_aaaa. (later, it will be moved
into opaque storage in the qctx, for use by the filter-aaaa module.)
- cleaned up style and braces
- move hooks.h to public include directory
- ns_hooktable_init() initializes a hook table. if NULL is passed in, it
initializes the global hook table
- ns_hooktable_save() saves a pointer to the current global hook table.
- ns_hooktable_reset() replaces the global hook table with different
one
- ns_hook_add() adds hooks at specified hook points in a hook table (or
the global hook table if the specified table is NULL)
- load and unload functions support dlopen() of hook modules (this is
adapted from dyndb and not yet functional)
- began adding new hook points to query.c
Witold Kręcicki
Evan HuntandWitold Kręcicki
Ondřej Surý
Witold KręcickiandOndřej Surý
Michał KępieńandOndřej Surý
Matthijs Mekking