The isc_refcount API that provides reference counting lost DbC checks for
overflows and underflows in the isc_refcount_{increment,decrement} functions.
The commit restores the overflow check in the isc_refcount_increment and
underflows check in the isc_refcount_decrement by checking for the previous
value to not be on the boundary.
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));
If a connection was closed early (right after accept()) an assertion
that assumed that the connection was still alive could be triggered
in accept_connection. Handle those errors properly and not with
assertions, free all the resources afterwards.
- the socket stat counters have been moved from socket.h to stats.h.
- isc_nm_t now attaches to the same stats counter group as
isc_socketmgr_t, so that both managers can increment the same
set of statistics
- isc__nmsocket_init() now takes an interface as a paramter so that
the address family can be determined when initializing the socket.
- based on the address family and socket type, a group of statistics
counters will be associated with the socket - for example, UDP4Active
with IPv4 UDP sockets and TCP6Active with IPv6 TCP sockets. note
that no counters are currently associated with TCPDNS sockets; those
stats will be handled by the underlying TCP socket.
- the counters are not actually used by netmgr sockets yet; counter
increment and decrement calls will be added in a later commit.
If pktinfo were supported then we could listen on :: for ipv6 and get
the information about the destination address from pktinfo structure passed
in recvmsg but this method is not portable and libuv doesn't support it - so
we need to listen on all interfaces.
We should verify that this doesn't impact performance (we already do it for
ipv4) and either remove all the ipv6pktinfo detection code or think of fixing
libuv.
- use UV_{TC,UD}P_IPV6ONLY for IPv6 sockets, keeping the pre-netmgr
behaviour.
- add a new listening_error bool flag which is set if the child
listener fails to start listening. This fixes a bug where named would
hang if, e.g., we failed to bind to a TCP socket.
For multithreaded TCP listening we need to pass a bound socket to all
listening threads. Instead of using uv_pipe handle passing method which
is quite complex (lots of callbacks, each of them with its own error
handling) we now use isc_uv_export() to export the socket, pass it as a
member of the isc__netievent_tcpchildlisten_t structure, and then
isc_uv_import() it in the child thread, simplifying the process
significantly.
These functions can be used to pass a uv handle between threads in a
safe manner. The other option is to use uv_pipe and pass the uv_handle
via IPC, which is way more complex. uv_export() and uv_import() functions
existed in libuv at some point but were removed later. This code is
based on the original removed code.
The Windows version of the code uses two functions internal to libuv;
a patch for libuv is attached for exporting these functions.
Ensure BIND is continuously tested on Tumbleweed, a pure rolling release
version of openSUSE. This will allow BIND incompatibilities with latest
upstream versions of its dependencies to be caught more quickly.
5339. [bug] With some libmaxminddb versions, named could erroneously
match an IP address not belonging to any subnet defined
in a given GeoIP2 database to one of the existing
entries in that database. [GL #1552]
Only comparing the value of the integer passed as the last argument to
MMDB_lookup_sockaddr() against MMDB_SUCCESS is not enough to ensure that
an MMDB lookup was successful - the 'found_entry' field of the
MMDB_lookup_result_s structure returned by that function also needs to
be true or else the remaining contents of that structure should be
ignored as the lookup failed. Extend the relevant logical condition in
get_entry_for() to ensure the latter does not return incorrect MMDB
entries for IP addresses which do not belong to any subnet defined in a
given GeoIP2 database.
