From ad9a5f731ae1a542f018655557a1a7fd3342c936 Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Tue, 3 Apr 2018 12:59:44 -0700
Subject: [PATCH] modules/m_room_member: Eval foreign invites; committer in
 modules/client/rooms/invite.

---
 modules/client/rooms/invite.cc | 92 ++++++++++++++++++++++++++++++++++
 modules/m_room_member.cc       | 51 +++++++++++++++++++
 2 files changed, 143 insertions(+)

diff --git a/modules/client/rooms/invite.cc b/modules/client/rooms/invite.cc
index 19701d956..e6edacab2 100644
--- a/modules/client/rooms/invite.cc
+++ b/modules/client/rooms/invite.cc
@@ -17,6 +17,9 @@ invite__room_user(const m::room &,
                   const m::user::id &target,
                   const m::user::id &sender);
 
+extern "C" m::event::id::buf
+invite__foreign(const m::event &);
+
 resource::response
 post__invite(client &client,
              const resource::request &request,
@@ -68,3 +71,92 @@ invite__room_user(const m::room &room,
 
 	return commit(room, event, content);
 }
+
+m::event::id::buf
+invite__foreign(const m::event &event)
+{
+	const auto &event_id
+	{
+		at<"event_id"_>(event)
+	};
+
+	const auto &room_id
+	{
+		at<"room_id"_>(event)
+	};
+
+	const m::user::id &target
+	{
+		at<"state_key"_>(event)
+	};
+
+	const unique_buffer<mutable_buffer> bufs
+	{
+		148_KiB
+	};
+
+	mutable_buffer buf{bufs};
+	const auto proto
+	{
+		json::stringify(buf, event)
+	};
+
+	m::v1::invite::opts opts;
+	opts.remote = target.host();
+	m::v1::invite request
+	{
+		room_id, event_id, proto, buf, std::move(opts)
+	};
+
+	request.wait(seconds(10)); //TODO: conf
+	request.get();
+
+	const json::array &response
+	{
+		request.in.content
+	};
+
+	const http::code &rcode
+	{
+		http::code(lex_cast<ushort>(response.at(0)))
+	};
+
+	if(rcode != http::OK)
+		throw http::error
+		{
+			rcode
+		};
+
+	const json::object &robject
+	{
+		response.at(1)
+	};
+
+	const m::event &revent
+	{
+		robject.at("event")
+	};
+
+	if(!verify(revent, target.host()))
+		throw m::error
+		{
+			http::UNAUTHORIZED, "M_INVITE_UNSIGNED",
+			"Invitee's host '%s' did not sign the invite.",
+			target.host()
+		};
+
+	if(!verify(revent, my_host()))
+		throw m::error
+		{
+			http::FORBIDDEN, "M_INVITE_MODIFIED",
+			"Invite event no longer verified by our signature.",
+			target.host()
+		};
+
+	m::vm::opts vmopts;
+	vmopts.non_conform.set(m::event::conforms::MISSING_PREV_STATE);
+	vmopts.infolog_accept = true;
+
+	m::vm::eval(revent, vmopts);
+	return at<"event_id"_>(revent);
+}
diff --git a/modules/m_room_member.cc b/modules/m_room_member.cc
index 8b5661e1a..c21ca2447 100644
--- a/modules/m_room_member.cc
+++ b/modules/m_room_member.cc
@@ -49,3 +49,54 @@ _join_room_hookfn
 	},
 	_join_room
 };
+
+using invite_foreign_proto = m::event::id::buf (const m::event &);
+m::import<invite_foreign_proto>
+invite__foreign
+{
+	"client_rooms", "invite__foreign"
+};
+
+static void
+invite_foreign(const m::event &event)
+{
+	const m::room::id &room_id
+	{
+		at<"room_id"_>(event)
+	};
+
+	const m::user::id &target
+	{
+		at<"state_key"_>(event)
+	};
+
+	const auto target_host
+	{
+		target.host()
+	};
+
+	const m::room::origins origins
+	{
+		room_id
+	};
+
+	if(origins.has(target_host))
+		return;
+
+	const auto eid
+	{
+		invite__foreign(event)
+	};
+
+}
+
+const m::hook
+invite_foreign_hookfn
+{
+	{
+		{ "_site",          "vm.commit"     },
+		{ "type",           "m.room.member" },
+		{ "membership",     "invite"        },
+	},
+	invite_foreign
+};