tree cd1e918dc3398b3a04dcff3e2bce8027970fc211
parent 35d23428502d205dd2876ad12941c7fd4160b099
author Harald Welte <laforge@gnumonks.org> 1529093068 +0200
committer Vadim Yanitskiy <axilirator@gmail.com> 1532881079 +0700

SS/USSD: implement basic USSE routing configuration for VTY

This change introduces basic Unstructured Supplementary Services
processing Entity (USSE) configuration for VTY by analogy with
ESME and SMPP.

The configuration is done by allocating USSE nodes, so each one
is bound to a particular GSUP-connection, and represents a single
processing entity. Then, one or more USSD-code matching patterns
(e.g. code, prefix, regexp) can be assigned to a particular USSE
node, so all matched USSD-requests will be handled by this node.

Among all other USSE nodes, which are basically External USSEs,
there is a special one called IUSSE - internal USSD handler.
It can be optionally configured to handle and answer simple
requests, like *#100#.

Also, it's possible to set the default USSE, which will handle
all USSD-requests unmatched by other USSEs. Otherwise,
unmatched requests are being rejected.

Change-Id: I3cfd7cd401ea32b7e92f1124d129099d9f7dc6e6