Websockets Server with UDP hole punching

.gitignore

@@ -28,6 +28,7 @@ res/keeperfx_icon.ico
 .header_checksum
 /deps/enet
 /deps/enet6
+/deps/libcurl
 /deps/zlib
 /deps/spng
 /deps/astronomy

Makefile

@@ -105,6 +105,7 @@ obj/bflib_datetm.o \
 obj/bflib_dernc.o \
 obj/bflib_enet.o \
 obj/net_portforward.o \
+obj/net_holepunch.o \
 obj/bflib_fileio.o \
 obj/bflib_filelst.o \
 obj/bflib_fmvids.o \
@@ -287,6 +288,7 @@ obj/net_input_lag.o \
 obj/net_received_packets.o \
 obj/net_redundant_packets.o \
 obj/net_checksums.o \
+obj/net_matchmaking.o \
 obj/packets.o \
 obj/packets_cheats.o \
 obj/packets_input.o \
@@ -377,6 +379,7 @@ LINKLIB = -mwindows \
 	-L"deps/enet6/lib" -lenet6 \
 	-L"deps/miniupnpc" -lminiupnpc \
 	-L"deps/libnatpmp" -lnatpmp -liphlpapi \
+	-L"deps/libcurl/lib" -lcurl -lwldap32 -lcrypt32 -lsecur32 -liphlpapi \
 	-L"deps/spng" -lspng \
 	-L"deps/centijson" -ljson \
 	-L"deps/zlib" -lminizip -lz \
@@ -395,7 +398,8 @@ INCS = \
 	-I"deps/openal/include" \
 	-I"deps/luajit/include" \
 	-I"deps/miniupnpc/include" \
-	-I"deps/libnatpmp/include"
+	-I"deps/libnatpmp/include" \
+	-I"deps/libcurl/include"
 CXXINCS =  $(INCS)
 
 STDOBJS   = $(subst obj/,obj/std/,$(OBJS))
@@ -435,7 +439,7 @@ HVLOGFLAGS = -DBFDEBUG_LEVEL=10
 WARNFLAGS = -Wall -W -Wshadow -Wno-sign-compare -Wno-unused-parameter -Wno-maybe-uninitialized -Wno-sign-compare -Wno-strict-aliasing -Wno-unknown-pragmas -Werror
 # disabled warnings: -Wextra -Wtype-limits
 CXXFLAGS = $(CXXINCS) -c -std=gnu++1y -fmessage-length=0 $(WARNFLAGS) $(DEPFLAGS) $(OPTFLAGS) $(DBGFLAGS) $(FTEST_DBGFLAGS) $(INCFLAGS)
-CFLAGS = $(INCS) -c -std=gnu11 -fmessage-length=0 $(WARNFLAGS) -Werror=implicit $(DEPFLAGS) $(FTEST_DBGFLAGS) $(OPTFLAGS) $(DBGFLAGS) $(INCFLAGS)
+CFLAGS = $(INCS) -c -std=gnu11 -fmessage-length=0 $(WARNFLAGS) -Werror=implicit $(DEPFLAGS) $(FTEST_DBGFLAGS) $(OPTFLAGS) $(DBGFLAGS) $(INCFLAGS) -DCURL_STATICLIB
 LDFLAGS = $(LINKLIB) $(OPTFLAGS) $(DBGFLAGS) $(FTEST_DBGFLAGS) $(LINKFLAGS) -Wl,-Map,"$(@:%.exe=%.map)"
 
 ifeq ($(USE_PRE_FILE), 1)
@@ -651,10 +655,11 @@ libexterns: libexterns.mk
 
 clean-libexterns: libexterns.mk
 	-$(MAKE) -f libexterns.mk clean-libexterns
-	-$(RM) -rf deps/enet6 deps/zlib deps/spng deps/astronomy deps/centijson deps/luajit deps/miniupnpc deps/libnatpmp
+	-$(RM) -rf deps/enet6 deps/zlib deps/spng deps/astronomy deps/centijson deps/luajit deps/miniupnpc deps/libnatpmp deps/libcurl
+	-$(RM) deps/libcurl-mingw32.tar.gz
 	-$(RM) libexterns
 
-deps/enet6 deps/zlib deps/spng deps/astronomy deps/centijson deps/ffmpeg deps/openal deps/luajit deps/miniupnpc deps/libnatpmp:
+deps/enet6 deps/zlib deps/spng deps/astronomy deps/centijson deps/ffmpeg deps/openal deps/luajit deps/miniupnpc deps/libnatpmp deps/libcurl:
 	$(MKDIR) $@
 
 src/api.c: deps/centijson/include/json.h
@@ -668,6 +673,7 @@ src/bflib_sndlib.cpp: deps/openal/include/AL/al.h
 src/net_resync.cpp: deps/zlib/include/zlib.h
 src/console_cmd.c: deps/luajit/include/lua.h
 src/net_portforward.cpp: deps/miniupnpc/include/miniupnpc/miniupnpc.h deps/libnatpmp/include/natpmp/natpmp.h
+src/net_matchmaking.c: deps/libcurl/include/curl/curl.h
 
 deps/enet6-mingw32.tar.gz:
 	curl -Lso $@ "https://github.com/dkfans/kfx-deps/releases/download/20260212/enet6-mingw32.tar.gz"
@@ -731,6 +737,12 @@ deps/libnatpmp-mingw32.tar.gz:
 deps/libnatpmp/include/natpmp/natpmp.h: deps/libnatpmp-mingw32.tar.gz | deps/libnatpmp
 	tar xzmf $< -C deps/libnatpmp
 
+deps/libcurl-mingw32.tar.gz:
+	curl -Lso $@ "https://github.com/dkfans/kfx-deps/releases/download/20260310/libcurl-mingw32.tar.gz"
+
+deps/libcurl/include/curl/curl.h: deps/libcurl-mingw32.tar.gz | deps/libcurl
+	tar xzmf $< -C deps/libcurl
+
 cppcheck: | src/ver_defs.h
 cppcheck: | deps/zlib/include/zlib.h
 cppcheck: | deps/spng/include/spng.h

docs/multiplayer_readme.txt

@@ -16,15 +16,22 @@ you are over a couple hundred kilometer away from each other.
 Multiplayer over ENET/UDP
 ------------------------------
 
+KeeperFX includes an online matchmaking server. Hosted games are listed there
+automatically, allowing others to browse and join without exchanging IP addresses.
+
 To host a ENET/UDP game:
 Make sure the port 5556 is open for traffic and is forwarded to port 5556 on
 your computer. When you have started the game, click Multiplayer -> ENET/UDP ->
-Create Game.
+Create Game. Your game will appear in the matchmaking list for others to join.
 
 To join a ENET/UDP game:
-Specify a command line option -sessions [ip_address]:5556 when starting game.
-For instance, if the host's IP address is 55.83.54.187, the appropriate command
-line option is -sessions 55.83.54.187:5556
+Click Multiplayer -> ENET/UDP to browse available games from the matchmaking
+server, then select one and click Join Game.
+
+Alternatively, join directly by specifying a command line option
+-sessions [ip_address]:5556 when starting game. For instance, if the host's IP
+address is 55.83.54.187, the appropriate command line option is
+-sessions 55.83.54.187:5556
 The launcher can be used to set this.
 
 Several sessions can be added to command line by prepending a semicolon before

linux.mk

@@ -211,6 +211,8 @@ src/map_utils.c \
 src/moonphase.c \
 src/net_checksums.c \
 src/net_game.c \
+src/net_holepunch.c \
+src/net_matchmaking.c \
 src/net_input_lag.c \
 src/net_received_packets.c \
 src/net_redundant_packets.c \
@@ -282,6 +284,7 @@ KFX_INCLUDES = \
 	-Ideps/centitoml \
 	-Ideps/astronomy/include \
 	-Ideps/enet6/include \
+	-Ideps/libcurl/include \
 	$(shell pkg-config --cflags-only-I luajit)
 
 KFX_CFLAGS += -g -DDEBUG -DBFDEBUG_LEVEL=0 -O3 -march=x86-64 $(KFX_INCLUDES) -Wall -Wextra -Werror -Wno-unused-parameter -Wno-absolute-value -Wno-unknown-pragmas -Wno-format-truncation -Wno-sign-compare
@@ -309,6 +312,7 @@ KFX_LDFLAGS += \
 	$(shell pkg-config --libs-only-l zlib) \
 	-lminiupnpc \
 	-lnatpmp \
+	-Ldeps/libcurl/lib -lcurl -lssl -lcrypto -lzstd \
 	-ldl
 
 TOML_SOURCES = \
@@ -331,11 +335,12 @@ endif
 all: bin/keeperfx
 
 clean:
-	rm -rf obj bin src/ver_defs.h deps/astronomy deps/centijson deps/enet6
+	rm -rf obj bin src/ver_defs.h deps/astronomy deps/centijson deps/enet6 deps/libcurl
+	rm -f deps/libcurl-lin64.tar.gz
 
 .PHONY: all clean
 
-bin/keeperfx: $(KFX_OBJECTS) $(TOML_OBJECTS) | bin
+bin/keeperfx: $(KFX_OBJECTS) $(TOML_OBJECTS) deps/libcurl/lib/libcurl.a | bin
 	$(CXX) -o $@ $(KFX_OBJECTS) $(TOML_OBJECTS) $(KFX_LDFLAGS)
 
 $(KFX_C_OBJECTS): obj/%.o: src/%.c src/ver_defs.h | obj
@@ -349,13 +354,15 @@ $(KFX_CXX_OBJECTS): obj/%.o: src/%.cpp src/ver_defs.h | obj
 $(TOML_OBJECTS): obj/centitoml/%.o: deps/centitoml/%.c | obj/centitoml
 	$(CC) $(TOML_CFLAGS) -c $< -o $@
 
-bin obj deps/astronomy deps/centijson deps/enet6 obj/centitoml:
+bin obj deps/astronomy deps/centijson deps/enet6 deps/libcurl obj/centitoml:
 	$(MKDIR) $@
 
 src/actionpt.c: deps/centijson/include/json.h
 src/api.c: deps/centijson/include/json.h
 src/bflib_enet.cpp: deps/enet6/include/enet6/enet.h
 src/moonphase.c: deps/astronomy/include/astronomy.h
+src/net_holepunch.c: deps/enet6/include/enet6/enet.h
+src/net_matchmaking.c: deps/libcurl/include/curl/curl.h
 deps/centitoml/toml_api.c: deps/centijson/include/json.h
 deps/centitoml/toml_conv.c: deps/centijson/include/json.h
 
@@ -377,6 +384,14 @@ deps/enet6-lin64.tar.gz:
 deps/enet6/include/enet6/enet.h: deps/enet6-lin64.tar.gz | deps/enet6
 	tar xzmf $< -C deps/enet6
 
+deps/libcurl-lin64.tar.gz:
+	curl -Lso $@ "https://github.com/dkfans/kfx-deps/releases/download/20260310/libcurl-lin64.tar.gz"
+
+deps/libcurl/lib/libcurl.a: deps/libcurl-lin64.tar.gz | deps/libcurl
+	tar xzmf $< -C deps/libcurl
+
+deps/libcurl/include/curl/curl.h: deps/libcurl/lib/libcurl.a
+
 src/ver_defs.h: version.mk
 	$(ECHO) "#define VER_MAJOR   $(VER_MAJOR)" > $@.swp
 	$(ECHO) "#define VER_MINOR   $(VER_MINOR)" >> $@.swp

src/bflib_datetm.cpp

@@ -25,10 +25,7 @@
 #include "bflib_basics.h"
 #include "game_legacy.h"
 
-#if defined(_WIN32)
-#define WIN32_LEAN_AND_MEAN
-#include <windows.h>
-#endif
+#include <SDL2/SDL.h>
 #include "post_inc.h"
 
 #ifdef __cplusplus
@@ -307,9 +304,7 @@ TbResult LbDateTimeDecode(const time_t *datetime,struct TbDate *curr_date,struct
 
 inline void LbDoMultitasking(void)
 {
-#if defined(_WIN32)
-    Sleep(LARGE_DELAY_TIME>>1); // This switches to other tasks
-#endif
+    SDL_Delay(LARGE_DELAY_TIME>>1);
 }
 
 TbBool LbSleepFor(TbClockMSec delay)