When the connection is closed by HAProxy, the status code provided in the
DISCONNECT frame is lost. By retransmitting it in the agent's reply, we are sure
to have it in the SPOE logs.
This patch may be backported in 1.8.
The commit c4dcaff3 ("BUG/MEDIUM: spoe: Flags are not encoded in network order")
introduced an incompatibility with older agents. So the major version of the
SPOP is increased to make the situation unambiguous. And because before the fix,
the protocol is buggy, the support of the version 1.0 is removed to be sure to
not continue to support buggy agents.
The agents in the contrib folder (spoa_example, modsecurity and mod_defender)
are also updated to announce the SPOP version 2.0.
So, to be clear, from the patch, connections to agents announcing the SPOP
version 1.0 will be rejected.
This patch must be backported in 1.8.
A recent fix on the SPOE revealed a mismatch between the SPOE specification and
the mod_defender implementation on the way flags are encoded or decoded. They
must be exchanged using the network bytes order and not the host one.
Be careful though, this patch breaks the compatiblity with HAProxy SPOE before
commit c4dcaff3 ("BUG/MEDIUM: spoe: Flags are not encoded in network order").
This is a service that talks SPOE protocol and uses the Mod Defender (a
NAXSI clone) functionality to detect HTTP attacks. It returns a HTTP
status code to indicate whether the request is suspicious or not, based on
NAXSI rules. The value of the returned code can be used in HAProxy rules
to determine if the HTTP request should be blocked/rejected.
Dragan Dosen
Christopher Faulet