serval-dna/overlay_probe.c
Andrew Bettison 71cbe86566 Switch to feature-driven linking
This introduces a new way of linking Serval executables and dynamic
libraries from static libraries like libservald.a -- called
"feature-driven" linking.

The Makefile now links servald and serval-tests from libservald.a,
rather than from an explicit list of object (.o) files.  Thanks to the
section-based method for registering functions such as HTTP handlers,
CLI commands and MDP handlers, these object files had become
"stand-alone" and hence were no longer included in the link because
there was no unresolved reference that required them to be linked in.

The new "feature.h" provides the DECLARE_FEATURE(name) macro that each
stand-alone source file uses to declare the named feature(s) it
provides.  Each executable can call the USE_FEATURE(name) macro in any
of its explicitly-linked source files to cause the corresponding
object(s) to be included in the link, eg, servald_features.c.

The DEFINE_BINDING() macro has been extended so that every individual
MDP binding is given a feature name based on its port number macro, eg,
"mdp_binding_MDP_PORT_ECHO".

Some features have been factored into their own separate source files so
they can be omitted or included in a build independently of each other:
- the MDP bindings for MDP_PORT_DNALOOKUP, MDP_PORT_ECHO,
  MDP_PORT_TRACE, MDP_PORT_KEYMAPREQUEST, MDP_PORT_RHIZOME_xxx,
  MDP_PORT_PROBE, MDP_PORT_STUN, MDP_PORT_STUNREQ
- the CLI "log" and "echo" commands
- the CLI "rhizome direct" command

The JNI source files are only compiled if the <jni.h> header is present,
otherwise they are omitted from libservald.so.
2016-10-19 09:33:01 +10:30

55 lines
1.9 KiB
C

/*
Serval DNA MDP overlay network link tracking
Copyright (C) 2016 Flinders University
Copyright (C) 2012-2013 Serval Project Inc.
Copyright (C) 2010-2012 Paul Gardner-Stephen
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include "serval.h"
#include "conf.h"
#include "route_link.h"
#include "overlay_interface.h"
#include "overlay_buffer.h"
#include "fdqueue.h"
/* Collection of unicast echo responses to detect working links */
DEFINE_BINDING(MDP_PORT_PROBE, overlay_mdp_service_probe);
static int overlay_mdp_service_probe(struct internal_mdp_header *header, struct overlay_buffer *payload)
{
IN();
if (header->source_port!=MDP_PORT_ECHO){
WARN("Probe packets should be returned from remote echo port");
RETURN(-1);
}
DEBUGF(overlayrouting, "Received probe response from %s", alloca_tohex_sid_t(header->source->sid));
if (header->source->reachable == REACHABLE_SELF)
RETURN(0);
uint8_t interface = ob_get(payload);
struct socket_address addr;
addr.addrlen = ob_remaining(payload);
if (addr.addrlen > sizeof(addr.store))
RETURN(WHY("Badly formatted probe packet"));
ob_get_bytes(payload, (unsigned char*)&addr.addr, addr.addrlen);
RETURN(link_unicast_ack(header->source, &overlay_interfaces[interface], &addr));
OUT();
}