From b97b503408911130d24d7f07f9247dca8314a316 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Roman=20Smr=C5=BE?= <roman.smrz@seznam.cz>
Date: Wed, 1 Jan 2020 21:27:11 +0100
Subject: Respond to data requests from network

---
 src/network.cpp | 112 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 108 insertions(+), 4 deletions(-)

(limited to 'src/network.cpp')

diff --git a/src/network.cpp b/src/network.cpp
index 40d1045..b1beb5c 100644
--- a/src/network.cpp
+++ b/src/network.cpp
@@ -10,7 +10,6 @@
 
 using std::scoped_lock;
 using std::unique_lock;
-using std::unique_ptr;
 
 using namespace erebos;
 
@@ -76,6 +75,29 @@ Server::Priv::~Priv()
 
 void Server::Priv::doListen()
 {
+	vector<uint8_t> buf(4096);
+	unique_lock<mutex> lock(dataMutex);
+
+	while (!finish) {
+		sockaddr_in paddr;
+
+		lock.unlock();
+		socklen_t addrlen = sizeof(paddr);
+		ssize_t ret = recvfrom(sock, buf.data(), buf.size(), 0,
+				(sockaddr *) &paddr, &addrlen);
+		if (ret < 0)
+			throw std::system_error(errno, std::generic_category());
+
+		if (auto dec = Object::decodePrefix(self.ref()->storage(),
+				buf.begin(), buf.begin() + ret)) {
+			if (auto header = TransportHeader::load(std::get<Object>(*dec))) {
+				scoped_lock<mutex> hlock(dataMutex);
+				handlePacket(getPeer(paddr), *header);
+			}
+		}
+
+		lock.lock();
+	}
 }
 
 void Server::Priv::doAnnounce()
@@ -108,9 +130,85 @@ void Server::Priv::doAnnounce()
 	}
 }
 
+Peer & Server::Priv::getPeer(const sockaddr_in & paddr)
+{
+	for (auto & peer : peers)
+		if (memcmp(&peer->addr, &paddr, sizeof paddr) == 0)
+			return *peer;
+
+	Peer * peer = new Peer { .sock = sock, .addr = paddr };
+	peers.emplace_back(peer);
+	return *peer;
+}
+
+void Server::Priv::handlePacket(Peer & peer, const TransportHeader & header)
+{
+	unordered_set<Digest> plaintextRefs;
+	for (const auto & obj : collectStoredObjects(*Stored<Object>::load(*self.ref())))
+		plaintextRefs.insert(obj.ref.digest());
+
+	for (auto & item : header.items) {
+		switch (item.type) {
+		case TransportHeader::Type::Acknowledged:
+			break;
+
+		case TransportHeader::Type::DataRequest: {
+			auto ref = std::get<Ref>(item.value);
+			if (plaintextRefs.find(ref.digest()) != plaintextRefs.end()) {
+				TransportHeader::Item hitem { TransportHeader::Type::DataResponse, ref };
+				peer.send(TransportHeader({ hitem }), { *ref });
+			}
+			break;
+		}
+
+		case TransportHeader::Type::DataResponse:
+			break;
+
+		case TransportHeader::Type::AnnounceSelf:
+			break;
+
+		case TransportHeader::Type::AnnounceUpdate:
+			break;
+
+		case TransportHeader::Type::ChannelRequest:
+			break;
+
+		case TransportHeader::Type::ChannelAccept:
+			break;
+
+		case TransportHeader::Type::ServiceType:
+			break;
+
+		case TransportHeader::Type::ServiceRef:
+			break;
+
+		}
+	}
+}
+
+void Peer::send(const TransportHeader & header, const vector<Object> & objs)
+{
+	vector<uint8_t> data, part;
+
+	part = header.toObject().encode();
+	data.insert(data.end(), part.begin(), part.end());
+	for (const auto & obj : objs) {
+		part = obj.encode();
+		data.insert(data.end(), part.begin(), part.end());
+	}
+
+	sendto(sock, data.data(), data.size(), 0,
+			(sockaddr *) &addr, sizeof(addr));
+}
+
 optional<TransportHeader> TransportHeader::load(const Ref & ref)
 {
-	auto rec = ref->asRecord();
+	return load(*ref);
+}
+
+optional<TransportHeader> TransportHeader::load(const Object & obj)
+{
+	auto rec = obj.asRecord();
 	if (!rec)
 		return nullopt;
 
@@ -176,7 +274,7 @@ optional<TransportHeader> TransportHeader::load(const Ref & ref)
 	return TransportHeader { .items = items };
 }
 
-Ref TransportHeader::store(const Storage & st) const
+Object TransportHeader::toObject() const
 {
 	vector<Record::Item> ritems;
 
@@ -220,5 +318,11 @@ Ref TransportHeader::store(const Storage & st) const
 		}
 	}
 
-	return st.storeObject(Record(std::move(ritems)));
+	return Object(Record(std::move(ritems)));
+}
+
+Ref TransportHeader::store(const Storage & st) const
+{
+
+	return st.storeObject(toObject());
 }
-- 
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