Add custom add-on server support

Defaults to https://kexquake.s3.amazonaws.com
(see https://kexquake.s3.amazonaws.com/index.html)

New command-line options:
  -addons <url>: specify a different server
  -noaddons    : disable add-on server support

Linux/CodeBlocks/QuakeSpasm-SDL2.cbp

@@ -46,6 +46,7 @@
 			<Add option="-logg" />
 			<Add option="-lmad" />
 			<Add option="-lm" />
+			<Add option="-lcurl" />
 		</Linker>
 		<Unit filename="../../Quake/anorm_dots.h" />
 		<Unit filename="../../Quake/anorms.h" />

Quake/Makefile

@@ -114,6 +114,9 @@ else
 NET_LIBS   :=
 endif
 
+NET_LIBS   += -lcurl
+CFLAGS     += $(shell $(PKG_CONFIG) --cflags libcurl)
+
 ifneq ($(VORBISLIB),vorbis)
 ifneq ($(VORBISLIB),tremor)
 $(error Invalid VORBISLIB setting)

Quake/Makefile.w32

@@ -93,6 +93,10 @@ endif
 CFLAGS     += $(DEFWINSOCK)
 NET_LIBS   := $(LIBWINSOCK)
 
+NET_LIBS   += -lcurl
+CFLAGS     += -I../Windows/curl/include
+LDFLAGS    += -L../Windows/curl/lib/x86
+
 ifneq ($(VORBISLIB),vorbis)
 ifneq ($(VORBISLIB),tremor)
 $(error Invalid VORBISLIB setting)

Quake/Makefile.w64

@@ -86,6 +86,10 @@ LIBWINSOCK := -lws2_32
 CFLAGS     += $(DEFWINSOCK)
 NET_LIBS   := $(LIBWINSOCK)
 
+NET_LIBS   += -lcurl
+CFLAGS     += -I../Windows/curl/include
+LDFLAGS    += -L../Windows/curl/lib/x64
+
 ifneq ($(VORBISLIB),vorbis)
 ifneq ($(VORBISLIB),tremor)
 $(error Invalid VORBISLIB setting)

Quake/common.c

@@ -25,6 +25,7 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 #include "quakedef.h"
 #include "q_ctype.h"
 #include "steam.h"
+#include <time.h>
 #include <errno.h>
 
 #include "miniz.h"
@@ -1582,6 +1583,64 @@ void COM_WriteFile (const char *filename, const void *data, int len)
 	Sys_FileClose (handle);
 }
 
+/*
+============
+COM_WriteFile_OSPath
+============
+*/
+qboolean COM_WriteFile_OSPath (const char *filename, const void *data, size_t len)
+{
+	qboolean	ret = false;
+	FILE		*f = Sys_fopen (filename, "wb");
+
+	if (f)
+	{
+		ret = fwrite (data, len, 1, f) == 1;
+		fclose (f);
+		if (!ret)
+			Sys_remove (filename);
+	}
+
+	return ret;
+}
+
+/*
+============
+COM_TempSuffix
+============
+*/
+char *COM_TempSuffix (unsigned seq)
+{
+	static const char base64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789=#";
+	static char buf[64];
+	time_t		now = 0;
+	int			r, len = 0, maxlen = sizeof (buf) - 1;
+
+	time (&now);
+	while (now && len < maxlen)
+	{
+		buf[len++] = base64[now & 63];
+		now >>= 6;
+	}
+
+	r = rand ();
+	while (r && len < maxlen)
+	{
+		buf[len++] = base64[r & 63];
+		r >>= 6;
+	}
+
+	while (seq && len < maxlen)
+	{
+		buf[len++] = base64[seq & 63];
+		seq >>= 6;
+	}
+
+	buf[len] = '\0';
+
+	return buf;
+}
+
 /*
 ============
 COM_CreatePath
@@ -1944,6 +2003,39 @@ byte *COM_LoadMallocFile_TextMode_OSPath (const char *path, long *len_out)
 	return data;
 }
 
+char *COM_NormalizeLineEndings (char *buffer)
+{
+	char *src, *dst;
+
+	src = dst = buffer;
+
+	while (*src)
+	{
+		if (src == dst)
+		{
+			while (*src && *src != '\r')
+				src++;
+			dst = src;
+		}
+		else
+		{
+			while (*src && *src != '\r')
+				*dst++ = *src++;
+		}
+
+		if (!*src)
+			break;
+
+		src++;
+		if (*src != '\n')
+			*dst++ = '\n';
+	}
+
+	*dst = '\0';
+
+	return buffer;
+}
+
 const char *COM_ParseIntNewline(const char *buffer, int *value)
 {
 	char *end;

Quake/common.h

@@ -263,6 +263,8 @@ extern char *q_strupr (char *str);
 extern int q_snprintf (char *str, size_t size, const char *format, ...) FUNC_PRINTF(3,4);
 extern int q_vsnprintf(char *str, size_t size, const char *format, va_list args) FUNC_PRINTF(3,0);
 
+#define PLURAL(count)	(&"s"[(count)==1])
+
 //============================================================================
 
 extern	THREAD_LOCAL char		com_token[1024];
@@ -296,6 +298,7 @@ void COM_DefaultExtension (char *path, const char *extension, size_t len);
 #endif
 const char *COM_FileGetExtension (const char *in); /* doesn't return NULL */
 void COM_ExtractExtension (const char *in, char *out, size_t outsize);
+char *COM_TempSuffix (unsigned seq);
 void COM_CreatePath (char *path);
 
 char *va (const char *format, ...) FUNC_PRINTF(1,2);
@@ -356,6 +359,7 @@ extern	char	com_gamedir[MAX_OSPATH];
 extern	THREAD_LOCAL int	file_from_pak;	// global indicating that file came from a pak
 
 void COM_WriteFile (const char *filename, const void *data, int len);
+qboolean COM_WriteFile_OSPath (const char *filename, const void *data, size_t len);
 int COM_OpenFile (const char *filename, int *handle, unsigned int *path_id);
 int COM_FOpenFile (const char *filename, FILE **file, unsigned int *path_id);
 qboolean COM_FileExists (const char *filename, unsigned int *path_id);
@@ -386,6 +390,9 @@ byte *COM_LoadMallocFile (const char *path, unsigned int *path_id);
 // Loads in "t" mode so CRLF to LF translation is performed on Windows.
 byte *COM_LoadMallocFile_TextMode_OSPath (const char *path, long *len_out);
 
+// Replaces CR/CRLF with LF.
+char *COM_NormalizeLineEndings (char *buffer);
+
 // Attempts to parse an int, followed by a newline.
 // Returns advanced buffer position.
 // Doesn't signal parsing failure, but this is not needed for savegame loading.

Quake/host.c

@@ -626,6 +626,108 @@ void Host_ClearMemory (void)
 }
 
 
+//==============================================================================
+//
+// Main thread APC queue
+//
+//==============================================================================
+
+typedef struct asyncproc_s
+{
+	void				(*func) (void *param);
+	void				*param;
+} asyncproc_t;
+
+typedef struct asyncqueue_s
+{
+	size_t				head;
+	size_t				tail;
+	size_t				capacity;
+	qboolean			teardown;
+	SDL_mutex			*mutex;
+	SDL_cond			*notfull;
+	asyncproc_t			*procs;
+} asyncqueue_t;
+
+static asyncqueue_t		async_queue;
+
+static void AsyncQueue_Init (asyncqueue_t *queue, size_t capacity)
+{
+	memset (queue, 0, sizeof (*queue));
+
+	if (!capacity)
+		capacity = 1024;
+	else
+		capacity = Q_nextPow2 (capacity);
+	queue->capacity = capacity;
+	capacity *= sizeof (queue->procs[0]);
+	queue->procs = (asyncproc_t *) malloc (capacity);
+	if (!queue->procs)
+		Sys_Error ("AsyncQueue_Init: malloc failed on %" SDL_PRIu64 " bytes", (uint64_t) capacity);
+
+	queue->mutex = SDL_CreateMutex ();
+	if (!queue->mutex)
+		Sys_Error ("AsyncQueue_Init: could not create mutex");
+
+	queue->notfull = SDL_CreateCond ();
+	if (!queue->notfull)
+		Sys_Error ("AsyncQueue_Init: could not create condition variable");
+}
+
+static void AsyncQueue_Push (asyncqueue_t *queue, void (*func) (void *param), void *param)
+{
+	asyncproc_t *proc;
+
+	if (!queue->mutex)
+		return;
+	SDL_LockMutex (queue->mutex);
+	while (!queue->teardown && queue->tail - queue->head >= queue->capacity)
+		SDL_CondWait (queue->notfull, queue->mutex);
+
+	if (!queue->teardown)
+	{
+		proc = &queue->procs[(queue->tail++) & (queue->capacity - 1)];
+		proc->func = func;
+		proc->param = param;
+	}
+
+	SDL_UnlockMutex (queue->mutex);
+}
+
+static void AsyncQueue_Drain (asyncqueue_t *queue)
+{
+	SDL_LockMutex (queue->mutex);
+	while (queue->head != queue->tail)
+	{
+		asyncproc_t *proc = &queue->procs[(queue->head++) & (queue->capacity - 1)];
+		proc->func (proc->param);
+		SDL_CondSignal (queue->notfull);
+	}
+	SDL_UnlockMutex (queue->mutex);
+}
+
+static void AsyncQueue_Destroy (asyncqueue_t *queue)
+{
+	if (!queue->mutex)
+		return;
+
+	SDL_LockMutex (queue->mutex);
+	queue->teardown = true;
+	SDL_UnlockMutex (queue->mutex);
+	SDL_CondBroadcast (queue->notfull);
+
+	AsyncQueue_Drain (queue);
+
+	SDL_DestroyCond (queue->notfull);
+	SDL_DestroyMutex (queue->mutex);
+	memset (queue, 0, sizeof (*queue));
+}
+
+void Host_InvokeOnMainThread (void (*func) (void *param), void *param)
+{
+	AsyncQueue_Push (&async_queue, func, param);
+}
+
 //==============================================================================
 //
 // Host Frame
@@ -914,6 +1016,9 @@ void _Host_Frame (double time)
 	accumtime += host_netinterval?CLAMP(0.0, time, 0.2):0.0;	//for renderer/server isolation
 	Host_AdvanceTime (time);
 
+// run async procs
+	AsyncQueue_Drain (&async_queue);
+
 // get new key events
 	Key_UpdateForDest ();
 	IN_UpdateInputMode ();
@@ -1113,6 +1218,7 @@ void Host_Init (void)
 	Mod_Init ();
 	NET_Init ();
 	SV_Init ();
+	AsyncQueue_Init (&async_queue, 1024);
 
 	Con_Printf ("Exe: " __TIME__ " " __DATE__ " (%s %d-bit)\n", SDL_GetPlatform (), (int)sizeof(void*)*8);
 	Con_Printf ("%4.1f megabyte heap\n", host_parms->memsize/ (1024*1024.0));
@@ -1126,12 +1232,6 @@ void Host_Init (void)
 		V_Init ();
 		Chase_Init ();
 		M_Init ();
-		ExtraMaps_Init (); //johnfitz
-		Modlist_Init (); //johnfitz
-		DemoList_Init (); //ericw
-		SaveList_Init ();
-		SkyList_Init ();
-		M_CheckMods ();
 		VID_Init ();
 		IN_Init ();
 		TexMgr_Init (); //johnfitz
@@ -1143,6 +1243,12 @@ void Host_Init (void)
 		BGM_Init();
 		Sbar_Init ();
 		CL_Init ();
+		Modlist_Init (); //johnfitz
+		ExtraMaps_Init (); //johnfitz
+		DemoList_Init (); //ericw
+		SaveList_Init ();
+		SkyList_Init ();
+		M_CheckMods ();
 	}
 
 	LOC_Init (); // for 2021 rerelease support.
@@ -1194,9 +1300,14 @@ void Host_Shutdown(void)
 // keep Con_Printf from trying to update the screen
 	scr_disabled_for_loading = true;
 
+	AsyncQueue_Destroy (&async_queue);
+
 	Host_ShutdownSave ();
 	Host_WriteConfiguration ();
 
+// stop downloads before shutting down networking
+	Modlist_ShutDown ();
+
 	NET_Shutdown ();
 
 	if (cls.state != ca_dedicated)