Also log an error when the input buffer contains more than MAXBUFSIZE bytes
already, instead of silently claiming the other side closed the connection.
Libevent 2.0's buffer code is not completely backward compatible with 1.4's.
In order to not (mis)use it anymore, we implement it ourselves. The buffers
are automatically expanding when necessary. When consuming data from the
buffer, no memmove()s are performed. Only when adding to the buffer would
write past the end do we shift everything back to the start.
OpenSSL depends on libdl and libz. When linking dynamically, libcrypto will
automatically link with the other two libraries. However, when linking
statically, these libraries need to be specified explicitly while linking. By
moving the autoconf checks for libdl and libz before those for libcrypto, we
ensure the latter test will be done with the proper libraries.
In commit 4a21aabada, code was added to detect
contradicting ADD_EDGE and DEL_EDGE messages being sent, which is an indication
of two nodes with the same Name connected to the same VPN. However, these
contradictory messages can also happen when there is a network partitioning. In
the former case a loop happens which causes many contradictory message, while
in the latter case only a few of those messages will be sent. So, now we
increase the threshold to at least 10 of both ADD_EDGE and DEL_EDGE messages.
Since tinc now handles UDP packets with a different source address and port
than used for TCP connections, the heuristic to treat edges as indirect when
tinc could detect that multiple addresses were used does not make sense
anymore, and can actually reduce performance.
Because we don't want to keep track of that, and this will cause the node
structure from being relinked into the node tree, which results in myself
pointing to an invalid address.
When a UDP packet was received with an unknown source address/port, and if it
failed a HMAC check against known keys, it could still incorrectly assign that
UDP address to another node. This would temporarily cause outgoing UDP packets
to go to the wrong destination address, until packets from the correct address
were received again.
