implemented a custom PDU/frame structure on top of UDP for game networking.

9 files changed, 102 insertions, 13 deletions

diff --git a/dat.h b/dat.h
index 40171cf..b4f7147 100644
--- a/dat.h
+++ b/dat.h
@@ -23,6 +23,10 @@ enum {
 	SCRHB	= SCRH+2*Borderwidth
 };
 
+enum {
+	Framesize = 4+4+4+2,
+};
+
 typedef struct VModel VModel;
 typedef struct Sprite Sprite;
 typedef struct Particle Particle;
@@ -31,9 +35,11 @@ typedef struct Ship Ship;
 typedef struct Star Star;
 typedef struct Universe Universe;
 typedef struct Derivative Derivative;
+
+typedef struct Frame Frame;
 typedef struct Conn Conn;
-typedef struct Player Player;
 typedef struct PInput PInput;
+typedef struct Player Player;
 typedef struct Lobby Lobby;
 typedef struct Party Party;
 
@@ -111,6 +117,16 @@ struct Derivative
 	Point2 dv; /* a */
 };
 
+struct Frame
+{
+	Udphdr *udp;
+	uint seq;
+	uint ack;
+	uint id;
+	ushort len;
+	uchar data[];
+};
+
 struct Conn
 {
 	char dir[40];
diff --git a/lobby.c b/lobby.c
index b1a1ff3..d5f56f2 100644
--- a/lobby.c
+++ b/lobby.c
@@ -1,5 +1,6 @@
 #include <u.h>
 #include <libc.h>
+#include <ip.h>
 #include <draw.h>
 #include "libgeometry/geometry.h"
 #include "dat.h"
diff --git a/musw.c b/musw.c
index 70a8a4b..10ca01b 100644
--- a/musw.c
+++ b/musw.c
@@ -1,5 +1,6 @@
 #include <u.h>
 #include <libc.h>
+#include <ip.h>
 #include <bio.h>
 #include <thread.h>
 #include <draw.h>
@@ -219,12 +220,23 @@ threadnetsend(void *arg)
 	uchar buf[1024];
 	int fd, n;
 	ulong kdown;
+	Frame *frame;
 
 	fd = *(int*)arg;
+	frame = emalloc(sizeof(Frame)+sizeof(kdown));
+	frame->udp = nil;
+	frame->seq = 223;
+	frame->ack = 222;
+	frame->id = ntruerand(100);
+	frame->len = sizeof(kdown);
 
 	for(;;){
 		kdown = recvul(kchan);
-		n = pack(buf, sizeof buf, "k", kdown);
+		frame->data[0] = kdown>>24;
+		frame->data[1] = kdown>>16;
+		frame->data[2] = kdown>>8;
+		frame->data[3] = kdown;
+		n = pack(buf, sizeof buf, "F", frame);
 		if(write(fd, buf, n) != n)
 			sysfatal("write: %r");
 	}
diff --git a/muswd.c b/muswd.c
index 8e07272..4ebd7e9 100644
--- a/muswd.c
+++ b/muswd.c
@@ -20,26 +20,33 @@ threadlisten(void *arg)
 	ushort rport, lport;
 	ulong kdown;
 	Ioproc *io;
-	Udphdr *udp;
+//	Udphdr *udp;
+	Frame *frame;
 
 	fd = *(int*)arg;
 	io = ioproc();
+	frame = emalloc(sizeof(Frame));
 
 	while((n = ioread(io, fd, buf, sizeof buf)) > 0){
-		if(n < Udphdrsize)
-			continue;
-
-		udp = (Udphdr*)buf;
-		p = buf+Udphdrsize;
+//		if(n < Udphdrsize)
+//			continue;
+//
+//		udp = (Udphdr*)buf;
+		p = buf;
 		e = buf+n;
 
-		rport = udp->rport[0]<<8 | udp->rport[1];
-		lport = udp->lport[0]<<8 | udp->lport[1];
+		unpack(p, e-p, "F", frame);
+
+		rport = frame->udp->rport[0]<<8 | frame->udp->rport[1];
+		lport = frame->udp->lport[0]<<8 | frame->udp->lport[1];
+		kdown = frame->data[0]<<24|
+			frame->data[1]<<16|
+			frame->data[2]<<8|
+			frame->data[3];
 
-		unpack(p, e-p, "k", &kdown);
 		if(debug)
-			fprint(2, "%I!%d → %I!%d | %d (%d) rcvd %.*lub\n",
-				udp->raddr, rport, udp->laddr, lport, threadid(), getpid(), sizeof(kdown)*8, kdown);
+			fprint(2, "%I!%d → %I!%d | %d (%d) rcvd seq %ud ack %ud id %ud len %ud %.*lub\n",
+				frame->udp->raddr, rport, frame->udp->laddr, lport, threadid(), getpid(), frame->seq, frame->ack, frame->id, frame->len, sizeof(kdown)*8, kdown);
 	}
 	closeioproc(io);
 }
diff --git a/pack.c b/pack.c
index be9b170..1096f6b 100644
--- a/pack.c
+++ b/pack.c
@@ -1,10 +1,23 @@
 #include <u.h>
 #include <libc.h>
+#include <ip.h>
 #include <draw.h>
 #include "libgeometry/geometry.h"
 #include "dat.h"
 #include "fns.h"
 
+static ushort
+get2(uchar *p)
+{
+	return p[0]<<8 | p[1];
+}
+
+static void
+put2(uchar *p, ushort u)
+{
+	p[0] = u>>8, p[1] = u;
+}
+
 static ulong
 get4(uchar *p)
 {
@@ -24,6 +37,7 @@ vpack(uchar *p, int n, char *fmt, va_list a)
 	ulong k;
 	FPdbleword d;
 	Point2 P;
+	Frame *F;
 
 	for(;;){
 		switch(*fmt++){
@@ -57,6 +71,19 @@ vpack(uchar *p, int n, char *fmt, va_list a)
 			put4(p, k), p += 4;
 
 			break;
+		case 'F':
+			F = va_arg(a, Frame*);
+
+			if(p+Framesize+F->len > e)
+				goto err;
+
+			put4(p, F->seq), p += 4;
+			put4(p, F->ack), p += 4;
+			put4(p, F->id), p += 4;
+			put2(p, F->len), p += 2;
+			memmove(p, F->data, F->len), p += F->len;
+
+			break;
 		}
 	}
 err:
@@ -70,6 +97,7 @@ vunpack(uchar *p, int n, char *fmt, va_list a)
 	ulong k;
 	FPdbleword d;
 	Point2 P;
+	Frame *F;
 
 	for(;;){
 		switch(*fmt++){
@@ -100,6 +128,27 @@ vunpack(uchar *p, int n, char *fmt, va_list a)
 			*va_arg(a, ulong*) = k;
 
 			break;
+		case 'F':
+			if(p+Udphdrsize+Framesize > e)
+				goto err;
+
+			F = va_arg(a, Frame*);
+
+			F->udp = (Udphdr*)p, p += Udphdrsize;
+			F->seq = get4(p), p += 4;
+			F->ack = get4(p), p += 4;
+			F->id = get4(p), p += 4;
+			F->len = get2(p), p += 2;
+
+			/* XXX: I'm not happy with this. */
+			if(p+F->len > e)
+				goto err;
+
+			F = erealloc(F, sizeof(Frame)+F->len);
+			memmove(F->data, p, F->len);
+			p += F->len;
+
+			break;
 		}
 	}
 err:
diff --git a/party.c b/party.c
index 2b2496a..cacf2e4 100644
--- a/party.c
+++ b/party.c
@@ -1,5 +1,6 @@
 #include <u.h>
 #include <libc.h>
+#include <ip.h>
 #include <draw.h>
 #include "libgeometry/geometry.h"
 #include "dat.h"
diff --git a/physics.c b/physics.c
index 5c8879d..f7fd284 100644
--- a/physics.c
+++ b/physics.c
@@ -1,5 +1,6 @@
 #include <u.h>
 #include <libc.h>
+#include <ip.h>
 #include <draw.h>
 #include "libgeometry/geometry.h"
 #include "dat.h"
diff --git a/sprite.c b/sprite.c
index cf5af36..c857a85 100644
--- a/sprite.c
+++ b/sprite.c
@@ -1,5 +1,6 @@
 #include <u.h>
 #include <libc.h>
+#include <ip.h>
 #include <draw.h>
 #include "libgeometry/geometry.h"
 #include "dat.h"
diff --git a/universe.c b/universe.c
index b620a61..5a4ea82 100644
--- a/universe.c
+++ b/universe.c
@@ -1,5 +1,6 @@
 #include <u.h>
 #include <libc.h>
+#include <ip.h>
 #include <draw.h>
 #include "libgeometry/geometry.h"
 #include "dat.h"