The isc_buffer_allocate() function now cannot fail with ISC_R_MEMORY.
This commit removes all the checks on the return code using the semantic
patch from previous commit, as isc_buffer_allocate() now returns void.
We weren't consistent about who should unreference the handle in
case of network error. Make it consistent so that it's always the
client code responsibility to unreference the handle - either
in the callback or right away if send function failed and the callback
will never be called.
If taskmgr is shutting down ns_client_setup will fail to create
a task for the newly created client, we weren't cleaning up already
created/attached things (memory context, server, clientmgr).
We pass interface as an opaque argument to tcpdns listening socket.
If we stop listening on an interface but still have in-flight connections
the opaque 'interface' is not properly reference counted, and we might
hit a dead memory. We put just a single source of truth in a listening
socket and make the child sockets use that instead of copying the
value from listening socket. We clean the callback when we stop listening.
as initial-key and static-key trust anchors will now be stored as a
DS rrset, code referencing keynodes storing DNSKEY trust anchors will
no longer be reached.
This commits removes superfluous checks when using the isc_refcount API.
Examples of superfluous checks:
1. The isc_refcount_decrement function ensures there was not underflow,
so this check is superfluous:
INSIST(isc_refcount_decrement(&r) > 0);
2 .The isc_refcount_destroy() includes check whether the counter
is zero, therefore this is superfluous:
INSIST(isc_refcount_decrement(&r) == 1 && isc_refcount_destroy(&r));
Some unit tests need various managers to be created before they are run.
The interface manager spawned during libns tests listens on a fixed port
number, which causes intermittent issues when multiple tests using an
interface manager are run concurrently. Make the interface manager
listen on a randomized port number to greatly reduce the risk of
multiple unit tests using the same port concurrently.
After the network manager rewrite, tcp-higwater stats was only being
updated when a valid DNS query was received over tcp.
It turns out tcp-quota is updated right after a tcp connection is
accepted, before any data is read, so in the event that some client
connect but don't send a valid query, it wouldn't be taken into
account to update tcp-highwater stats, that is wrong.
This commit fix tcp-highwater to update its stats whenever a tcp connection
is established, independent of what happens after (timeout/invalid
request, etc).
During BIND startup it scans for network interfaces available, in this
process it ensures that for every interface it will bind and listen to,
at least one socket will be always available accepting connections on
that interface, this way avoiding some DOS attacks that could exploit
tcp quota on some interface and make others unavailable.
In the previous network implementation this initial "reserved" tcp-quota
used by BIND was already been added to the tcp-highwater stats, but with
the new network code it was necesary to add this workaround to ensure
tcp-highwater stats reflect the tcp-quota used by BIND after startup.
- restore support for tcp-initial-timeout, tcp-idle-timeout,
tcp-keepalive-timeout and tcp-advertised-timeout configuration
options, which were ineffective previously.
when the TCPDNS_CLIENTS_PER_CONN limit has been exceeded for a TCP
DNS connection, switch to sequential mode to ensure that memory cannot
be exhausted by too many simultaneous queries.
-Wl,-z,interpose is not supported.
-Wl,rpath=<path> is not supported use -Wl,rpath,<path> instead.
Use @SO@ for loadable extension.
Use -L <path> -l libwrap instead of libwrap.sa.
- ns__client_request() is now called by netmgr with an isc_nmhandle_t
parameter. The handle can then be permanently associated with an
ns_client object.
- The task manager is paused so that isc_task events that may be
triggred during client processing will not fire until after the netmgr is
finished with it. Before any asynchronous event, the client MUST
call isc_nmhandle_ref(client->handle), to prevent the client from
being reset and reused while waiting for an event to process. When
the asynchronous event is complete, isc_nmhandle_unref(client->handle)
must be called to ensure the handle can be reused later.
- reference counting of client objects is now handled in the nmhandle
object. when the handle references drop to zero, the client's "reset"
callback is used to free temporary resources and reiniialize it,
whereupon the handle (and associated client) is placed in the
"inactive handles" queue. when the sysstem is shutdown and the
handles are cleaned up, the client's "put" callback is called to free
all remaining resources.
- because client allocation is no longer handled in the same way,
the '-T clienttest' option has now been removed and is no longer
used by any system tests.
- the unit tests require wrapping the isc_nmhandle_unref() function;
when LD_WRAP is supported, that is used. otherwise we link a
libwrap.so interposer library and use that.
When a task manager is created, we can now specify an `isc_nm`
object to associate with it; thereafter when the task manager is
placed into exclusive mode, the network manager will be paused.
The double-locked queue implementation is still currently in use
in ns_client, but will be replaced by a fetch-and-add array queue.
This commit moves it from queue.h to list.h so that queue.h can be
used for the new data structure, and clean up dependencies between
list.h and types.h. Later, when the ISC_QUEUE is no longer is use,
it will be removed completely.
When doing regular signing expiry time is jittered to make sure
that the re-signing times are not clumped together. This expands
this behaviour to expiry times of dynamically added records.
When incrementally re-signing a zone use the full jitter range if
the server appears to have been offline for greater than 5 minutes
otherwise use a small jitter range of 3600 seconds. This will stop
the signatures becoming more clustered if the server has been off
line for a significant period of time (> 5 minutes).
This variable will report the maximum number of simultaneous tcp clients
that BIND has served while running.
It can be verified by running rndc status, then inspect "tcp high-water:
count", or by generating statistics file, rndc stats, then inspect the
line with "TCP connection high-water" text.
The tcp-highwater variable is atomically updated based on an existing
tcp-quota system handled in ns/client.c.
The coccinellery repository provides many little semantic patches to fix common
problems in the code. The number of semantic patches in the coccinellery
repository is high and most of the semantic patches apply only for Linux, so it
doesn't make sense to run them on regular basis as the processing takes a lot of
time.
The list of issue found in BIND 9, by no means complete, includes:
- double assignment to a variable
- `continue` at the end of the loop
- double checks for `NULL`
- useless checks for `NULL` (cannot be `NULL`, because of earlier return)
- using `0` instead of `NULL`
- useless extra condition (`if (foo) return; if (!foo) { ...; }`)
- removing & in front of static functions passed as arguments
Witold Kręcicki
Ondřej Surý
Tinderbox User
Evan Hunt
Ondřej Surý
Michał Kępień
Diego FronzaandEvan Hunt
Mark AndrewsandOndřej Surý
