consider local addresses as candidates for connecting to server

6 files changed, 82 insertions, 25 deletions

diff --git a/client.lua b/client.lua
index 30f886d..61fe8c2 100644
--- a/client.lua
+++ b/client.lua
@@ -12,12 +12,22 @@ local function create_client(secret)
     return clt
 end
 
-local function connect(clt, addr)
-    clt.server = clt.host:connect(addr)
+local function connect(clt, addrs)
+    clt.server_candidates = {}
+    for _, addr in ipairs(addrs) do
+        clt.server_candidates[clt.host:connect(addr)] = true
+    end
     clt.server_req = socket.gettime()
     clt.status = "wait_server"
 end
 
+local function remove_candidates(clt)
+    for s in pairs(clt.server_candidates) do
+        s:disconnect()
+    end
+    clt.server_candidates = nil
+end
+
 function client.join(invite, match_addr)
     local invite_dec = util.base64_dec(invite)
     if not invite_dec then
@@ -38,17 +48,24 @@ end
 
 function client.connect(addr, secret)
     local clt = create_client(secret)
-    connect(clt, addr)
+    connect(clt, { addr })
     return clt
 end
 
 local function handle_match(clt, pkt)
     if pkt.type == "client_join" then
-        if type(pkt.peer_addr) ~= "string" then
-            print("[client] client_join: invalid peer_addr")
+        if type(pkt.candidates) ~= "table" then
+            print("[client] client_join: invalid candidates")
             return
         end
-        connect(clt, pkt.peer_addr)
+        for _, c in ipairs(pkt.candidates) do
+            if type(c) ~= "string" then
+                print("[client] client_join: invalid candidates")
+                return
+            end
+        end
+
+        connect(clt, pkt.candidates)
     elseif pkt.type == "client_join_fail" then
         clt.status = "fail_match"
     end
@@ -83,17 +100,20 @@ function client.update(clt)
                 end
             end
         elseif event.type == "connect" then
-            if event.peer == clt.match and clt.status == "wait_match" then
+            if clt.status == "wait_match" and event.peer == clt.match then
                 util.send(clt.match, { type = "match_join", game_id = util.base64_enc(clt.game_id) })
-            elseif event.peer == clt.server and clt.status == "wait_server" then
+            elseif clt.status == "wait_server" and clt.server_candidates[event.peer] then
+                clt.server = event.peer
+                clt.server_candidates[clt.server] = nil
                 util.send(clt.server, { type = "server_hi", secret = util.base64_enc(clt.secret) })
+                remove_candidates(clt)
             else
                 event.peer:disconnect_now()
             end
             print("[client] connect " .. tostring(event.peer))
         elseif event.type == "disconnect" then
             print("[client] disconnect " .. tostring(event.peer))
-            if event.peer == clt.server and clt.status == "active" then
+            if event.peer == clt.server then
                 clt.status = "disco"
             end
         end
@@ -122,6 +142,7 @@ end
 function client.close(clt)
     if clt.match then clt.match:disconnect() end
     if clt.server then clt.server:disconnect() end
+    if clt.server_candidates then remove_candidates(clt) end
     clt.host:flush()
     clt.host:destroy()
 end
diff --git a/common.lua b/common.lua
index 6a04d0f..98268ab 100644
--- a/common.lua
+++ b/common.lua
@@ -1,5 +1,9 @@
 return {
     default_match_addr = "ivy.vlhl.dev:18252",
+    -- any public IP address (in this case: ivy.vlhl.dev)
+    -- this address is not pinged or connected to
+    -- used to look up our own local ip address
+    route_lookup_target = "94.16.117.28",
     gameid_len = 8,
     secret_len = 4,
 }
diff --git a/main.lua b/main.lua
index 30f21a5..a5dd579 100644
--- a/main.lua
+++ b/main.lua
@@ -73,6 +73,7 @@ local function start_server(save)
     else
         srv = s
     end
+    show(dialog.loading, "Registering game...")
 end
 
 local function create_save(save)
diff --git a/matchsrv.lua b/matchsrv.lua
index 315573c..a8ae92e 100755
--- a/matchsrv.lua
+++ b/matchsrv.lua
@@ -5,33 +5,44 @@ local common = require("common")
 
 local host = enet.host_create("0.0.0.0:18252")
 
-local game_to_peer = {}
-local peer_to_game = {}
+local games_by_id = {}
+local games_by_peer = {}
 
 local function remove_game(peer)
-    local game = peer_to_game[peer]
+    local game = games_by_peer[peer]
     if game then
-        game_to_peer[game] = nil
-        peer_to_game[peer] = nil
+        games_by_id[game.id] = nil
+        games_by_peer[game.peer] = nil
     end
 end
 
 local function handle(peer, pkt)
     if pkt.type == "match_register" then
+        if pkt.candidates ~= nil and type(pkt.candidates) ~= "table" then
+            return
+        end
+
+        local game = {
+            peer = peer,
+            id = util.rand_string(common.gameid_len),
+            candidates = pkt.candidates or {},
+        }
+        table.insert(game.candidates, tostring(peer))
+
         remove_game(peer)
-        local game_id = util.rand_string(common.gameid_len)
-        peer_to_game[peer] = game_id
-        game_to_peer[game_id] = peer
-        util.send(peer, { type = "server_match", game_id = util.base64_enc(game_id) })
+        games_by_peer[game.peer] = game
+        games_by_id[game.id] = game
+
+        util.send(peer, { type = "server_match", game_id = util.base64_enc(game.id) })
         print(peer, "registered game")
     elseif pkt.type == "match_join" then
         local game_id = type(pkt.game_id) == "string" and util.base64_dec(pkt.game_id)
         if game_id then
-            local server = game_id and game_to_peer[game_id]
-            if server then
-                util.send(server, { type = "server_join", peer_addr = tostring(peer) })
-                util.send(peer, { type = "client_join", peer_addr = tostring(server) })
-                print(peer, "joined game", server)
+            local game = games_by_id[game_id]
+            if game then
+                util.send(game.peer, { type = "server_join", peer_addr = tostring(peer) })
+                util.send(peer, { type = "client_join", peer_addr = tostring(game.peer), candidates = game.candidates })
+                print(peer, "joined game", game.peer)
             else
                 util.send(peer, { type = "client_join_fail" })
                 print(peer, "failed to join game")
diff --git a/server.lua b/server.lua
index 8d85dcd..a51564c 100644
--- a/server.lua
+++ b/server.lua
@@ -3,9 +3,18 @@ local socket = require("socket")
 local util = require("util")
 local common = require("common")
 local save_file = require("save_file")
+local socket = require("socket")
 
 local server = {}
 
+local function get_local_ip()
+    local sock = socket.udp()
+    sock:setpeername(common.route_lookup_target, 1024)
+    local ip = sock:getsockname()
+    sock:close()
+    return ip
+end
+
 local function migrate_save(save)
     save.players = save.players or {}
 end
@@ -108,7 +117,11 @@ function server.create(filename, match_addr)
 end
 
 function server.port(srv)
-    return srv.host:get_socket_address():match(":([^:]*)$")
+    return util.split_addr(srv.host:get_socket_address()).port
+end
+
+function server.local_addr(srv)
+    return get_local_ip() .. ":" .. server.port(srv)
 end
 
 local function handle_match(srv, pkt)
@@ -214,7 +227,8 @@ function server.update(srv, wait)
             end
         elseif event.type == "connect" then
             if event.peer == srv.match then
-                util.send(srv.match, { type = "match_register" })
+                util.send(srv.match, { type = "match_register",
+                    candidates = { server.local_addr(srv) } })
             end
             print("[server] connect " .. tostring(event.peer))
         elseif event.type == "disconnect" then
diff --git a/util.lua b/util.lua
index dda250e..8eab1db 100644
--- a/util.lua
+++ b/util.lua
@@ -39,6 +39,11 @@ else
     end
 end
 
+local function split_addr(addr)
+    local host, port = addr:match("(.*):([^:]*)$")
+    return { host = host, port = port }
+end
+
 return {
     rand_string = rand_string,
     mkdir = mkdir,
@@ -47,4 +52,5 @@ return {
     json_dec = json_dec,
     json_enc = json_enc,
     send = send,
+    split_addr = split_addr,
 }