2 files changed, 50 insertions(+), 32 deletions(-)

M ip/gre.c
M ip/udp.c

@@ 11,8 11,8 @@
 
 enum
 {
-	GRE_IPHDRSIZE	= 20,		/* size of ip header */
-	GRE_HDRSIZE	= 4,		/* minimum size of GRE header */
+	GRE_IPONLY	= 12,		/* size of ip header */
+	GRE_IPPLUSGRE	= 12,		/* minimum size of GRE header */
 	IP_GREPROTO	= 47,
 
 	GRErxms		= 200,


@@ 122,6 122,7 @@ grekick(Conv *c, int l)
 {
 	GREhdr *ghp;
 	Block *bp;
+	ulong raddr, laddr;
 
 	USED(l);
 


@@ 130,20 131,27 @@ grekick(Conv *c, int l)
 		return;
 
 	/* Make space to fit ip header (gre header already there) */
-	bp = padblock(bp, GRE_IPHDRSIZE);
+	bp = padblock(bp, GRE_IPONLY);
 	if(bp == nil)
 		return;
 
 	/* make sure the message has a GRE header */
-	bp = pullupblock(bp, GRE_IPHDRSIZE+GRE_HDRSIZE);
+	bp = pullupblock(bp, GRE_IPONLY+GRE_IPPLUSGRE);
 	if(bp == nil)
 		return;
 
 	ghp = (GREhdr *)(bp->rp);
 
+	raddr = nhgetl(ghp->src);
+	laddr = nhgetl(ghp->dst);
+	if(raddr == 0)
+		raddr = c->raddr;
+	if(laddr == 0 || Mediaforme(ghp->dst) <= 0)
+		laddr = c->laddr;
+
 	ghp->proto = IP_GREPROTO;
-	hnputl(ghp->dst, c->raddr);
-	hnputl(ghp->src, c->laddr);
+	hnputl(ghp->dst, raddr);
+	hnputl(ghp->src, laddr);
 	hnputs(ghp->eproto, c->rport);
 	ghp->frag[0] = 0;
 	ghp->frag[1] = 0;


@@ 184,12 192,12 @@ greiput(Media *m, Block *bp)
 	/*
 	 * Trim the packet down to data size
 	 */
-	len = nhgets(ghp->len) - GRE_IPHDRSIZE;
-	if(len < GRE_HDRSIZE){
+	len = nhgets(ghp->len) - GRE_IPONLY;
+	if(len < GRE_IPPLUSGRE){
 		freeblist(bp);
 		return;
 	}
-	bp = trimblock(bp, GRE_IPHDRSIZE, len);
+	bp = trimblock(bp, GRE_IPONLY, len);
 	if(bp == nil){
 		gre.lenerr++;
 		return;

@@ 15,8 15,7 @@ enum
 	UDP_HDRSIZE	= 20,
 	UDP_IPHDR	= 8,
 	IP_UDPPROTO	= 17,
-	UDP_USEAD	= 6,
-	UDP_RELSIZE	= 16,
+	UDP_USEAD	= 12,
 
 	Udprxms		= 200,
 	Udptickms	= 100,


@@ 123,8 122,8 @@ void
 udpkick(Conv *c, int l)
 {
 	Udphdr *uh;
-	ushort port;
-	Ipaddr addr;
+	ushort rport;
+	Ipaddr laddr, raddr;
 	Block *bp, *f;
 	Udpcb *ucb;
 	int dlen, ptcllen;


@@ 143,13 142,20 @@ udpkick(Conv *c, int l)
 			freeblist(bp);
 			return;
 		}
-		addr = nhgetl(bp->rp);
+		raddr = nhgetl(bp->rp);
 		bp->rp += 4;
-		port = nhgets(bp->rp);
+		laddr = nhgetl(bp->rp);
+		if(laddr != 0 && Mediaforme(bp->rp) <= 0)
+			laddr = 0;
+		bp->rp += 4;
+		rport = nhgets(bp->rp);
+		bp->rp += 2;
+		/* ignore local port number */
 		bp->rp += 2;
 	} else {
-		addr = 0;
-		port = 0;
+		raddr = 0;
+		rport = 0;
+		laddr = 0;
 	}
 
 	/* Round packet up to even number of bytes */


@@ 179,11 185,12 @@ udpkick(Conv *c, int l)
 	uh->frag[1] = 0;
 	hnputs(uh->udpplen, ptcllen);
 	if(ucb->headers) {
-		hnputl(uh->udpdst, addr);
-		hnputs(uh->udpdport, port);
-
-		/* pick the closest source address (best we can do) */
-		hnputl(uh->udpsrc, Mediagetsrc(uh->udpdst));
+		hnputl(uh->udpdst, raddr);
+		hnputs(uh->udpdport, rport);
+		if(laddr)
+			hnputl(uh->udpsrc, laddr);
+		else
+			hnputl(uh->udpsrc, Mediagetsrc(uh->udpdst));
 	} else {
 		hnputl(uh->udpdst, c->raddr);
 		hnputs(uh->udpdport, c->rport);


@@ 204,10 211,10 @@ udpiput(Media *m, Block *bp)
 {
 	int len;
 	Udphdr *uh;
-	Ipaddr addr;
 	Conv *c, **p;
 	Udpcb *ucb;
-	ushort dport, sport;
+	Ipaddr raddr, laddr;
+	ushort rport, lport;
 
 	USED(m);
 	uh = (Udphdr*)(bp->rp);


@@ 217,7 224,8 @@ udpiput(Media *m, Block *bp)
 	len = nhgets(uh->udplen);
 	hnputs(uh->udpplen, len);
 
-	addr = nhgetl(uh->udpsrc);
+	raddr = nhgetl(uh->udpsrc);
+	laddr = nhgetl(uh->udpdst);
 
 	if(udpsum && nhgets(uh->udpcksum)) {
 		if(ptclcsum(bp, UDP_IPHDR, len+UDP_PHDRSIZE)) {


@@ 228,8 236,8 @@ udpiput(Media *m, Block *bp)
 		}
 	}
 
-	dport = nhgets(uh->udpdport);
-	sport = nhgets(uh->udpsport);
+	lport = nhgets(uh->udpdport);
+	rport = nhgets(uh->udpsport);
 
 	/* Look for a conversation structure for this port */
 	c = nil;


@@ 237,7 245,7 @@ udpiput(Media *m, Block *bp)
 		c = *p;
 		if(c->inuse == 0)
 			continue;
-		if(c->lport == dport && (c->rport == 0 || c->rport == sport))
+		if(c->lport == lport && (c->rport == 0 || c->rport == rport))
 			break;
 	}
 


@@ 261,14 269,16 @@ udpiput(Media *m, Block *bp)
 	if(ucb->headers) {
 		/* pass the src address */
 		bp = padblock(bp, UDP_USEAD);
-		hnputl(bp->rp, addr);
-		hnputs(bp->rp+4, sport);
+		hnputl(bp->rp, raddr);
+		hnputl(bp->rp+4, laddr);
+		hnputs(bp->rp+8, rport);
+		hnputs(bp->rp+10, lport);
 	} else {
 		/* connection oriented udp */
 		if(c->raddr == 0){
 			/* save the src address in the conversation */
-		 	c->raddr = addr;
-			c->rport = sport;
+		 	c->raddr = raddr;
+			c->rport = rport;
 
 			/* reply with the same ip address (if not broadcast) */
 			if(Mediaforme(uh->udpdst) > 0)