[9front] [PATCH] ipv6 flow label support

[Arne Meyer <meyer.arne83@netcologne.de>]

[-- Attachment #1: Type: text/plain, Size: 280 bytes --]

Hello,

this patch implements ipv6 flow labels. The labels are generated by hashing the 5-tuple (src,dst,proto,srcport,dstport) with the fnv-1a hash function (http://www.isthe.com/chongo/tech/comp/fnv/index.html). Flow labels are implemented for tcp, udp and esp.

Greetings,
Arne

[-- Attachment #2: flowlabel.patch --]
[-- Type: application/octet-stream, Size: 3509 bytes --]

diff 970d3b7eb7dc56aa84924dd68c4c39fd1df5d1f5 uncommitted
--- a/sys/src/9/ip/esp.c
+++ b/sys/src/9/ip/esp.c
@@ -339,6 +339,7 @@
 	Esptail *et;
 	Userhdr *uh;
 	Versdep vers;
+	uint hash;
 
 	getverslens(convipvers(c), &vers);
 	bp = qget(c->wq);
@@ -414,6 +415,11 @@
 
 		hnputl(eh6->espspi, ecb->spi);
 		hnputl(eh6->espseq, ++ecb->seq);
+
+		hash = flowhash(eh6->src, eh6->dst, IP_ESPPROTO, eh->spi, eh->spi+2);
+		eh6->vcf[1] = hash>>16;
+		eh6->vcf[2] = hash>>8;
+		eh6->vcf[3] = hash;
 	}
 
 	/* compute secure hash */
--- a/sys/src/9/ip/ipaux.c
+++ b/sys/src/9/ip/ipaux.c
@@ -578,3 +578,38 @@
 		csum = (csum & 0xFFFF) + v;
 	hnputs(pcsum, csum^0xFFFF);
 }
+
+#define FNV_INIT	0x811c9dc5
+#define FNV_PRIME	0x01000193
+
+static uint fnv(uchar *v, int l, uint h)
+{
+	int i;
+
+	for(i = 0; i < l; i++){
+		h ^= (uint) v[i];
+		h *= FNV_PRIME;
+	}
+
+	return h;
+}
+
+/*
+ * Compute ipv6 flowhash withe the fnv-1a hash function
+ */
+uint flowhash6(uchar *s, uchar *d, uchar p, uchar *sp, uchar *dp)
+{
+	uint h;
+
+	h = FNV_INIT;
+
+	h = fnv(s, IPaddrlen, h);
+	h = fnv(d, IPaddrlen, h);
+	h = fnv(&p, 1, h);
+	h = fnv(sp, 2, h);
+	h = fnv(dp, 2, h);
+
+	h = (h >> 20) ^ (h & 0x0fffff);
+
+	return h;
+}
\ No newline at end of file
--- a/sys/src/9/ip/ipv6.c
+++ b/sys/src/9/ip/ipv6.c
@@ -97,7 +97,7 @@
 	} else {
 		eh->vcf[0] = IP_VER6;
 		eh->vcf[0] |= tos >> 4;
-		eh->vcf[1]  = tos << 4;
+		eh->vcf[1] |= tos << 4;
 	}
 	eh->ttl = ttl;
 
--- a/sys/src/9/ip/ipv6.h
+++ b/sys/src/9/ip/ipv6.h
@@ -164,6 +164,7 @@
 extern int v6aNpreflen;
 extern int v6aLpreflen;
 
+uint flowhash6(uchar *, uchar *, uchar, uchar *, uchar *);
 void ipv62smcast(uchar *, uchar *);
 void icmpns6(Fs *f, uchar* src, int suni, uchar* targ, int tuni, uchar* mac, int maclen);
 void icmpna6(Fs *f, uchar* src, uchar* dst, uchar* targ, uchar* mac, int maclen, uchar flags);
--- a/sys/src/9/ip/tcp.c
+++ b/sys/src/9/ip/tcp.c
@@ -6,6 +6,7 @@
 #include	"../port/error.h"
 
 #include	"ip.h"
+#include	"ipv6.h"
 
 enum
 {
@@ -1025,6 +1026,7 @@
 	ushort csum;
 	ushort hdrlen, optpad = 0;
 	uchar *opt;
+	uint hash;
 
 	hdrlen = TCP6_HDRSIZE;
 	if(tcph->flags & SYN){
@@ -1090,7 +1092,11 @@
 
 	/* move from pseudo header back to normal ip header */
 	memset(h->vcf, 0, 4);
+	hash = flowhash6(h->tcpsrc, h->tcpdst, IP_TCPPROTO, h->tcpsport, h->tcpdport);
 	h->vcf[0] = IP_VER6;
+	h->vcf[1] = hash>>16;
+	h->vcf[2] = hash>>8;
+	h->vcf[3] = hash;
 	hnputs(h->ploadlen, hdrlen+dlen);
 	h->proto = ph->proto;
 
--- a/sys/src/9/ip/udp.c
+++ b/sys/src/9/ip/udp.c
@@ -193,6 +193,7 @@
 	int version;
 	Routehint *rh;
 	ushort csum;
+	uint hash;
 
 	upriv = c->p->priv;
 	f = c->p->f;
@@ -313,7 +314,11 @@
 			csum = 0xffff;	/* -0 */
 		hnputs(uh6->udpcksum, csum);
 		memset(uh6, 0, 8);
+		hash = flowhash6(uh6->udpsrc, uh6->udpdst, IP_UDPPROTO, uh6->udpsport, uh6->udpdport);
 		uh6->viclfl[0] = IP_VER6;
+		uh6->viclfl[1] = hash>>16;
+		uh6->viclfl[2] = hash>>8;
+		uh6->viclfl[3] = hash;
 		hnputs(uh6->len, ptcllen);
 		uh6->nextheader = IP_UDPPROTO;
 		ipoput6(f, bp, nil, c->ttl, c->tos, rh);
--- a/sys/src/cmd/ip/snoopy/ip6.c
+++ b/sys/src/cmd/ip/snoopy/ip6.c
@@ -279,8 +279,8 @@
 	if(len < m->pe - m->ps)
 		m->pe = m->ps + len;
 
-	m->p = seprint(m->p, m->e, "s=%I d=%I ttl=%3d pr=%d ln=%d",
-		h->src, h->dst, h->ttl, h->proto, NetS(h->length));
+	m->p = seprint(m->p, m->e, "s=%I d=%I ttl=%3d pr=%d fl=%ux ln=%d",
+		h->src, h->dst, h->ttl, h->proto, Net3(h->vcf+1) & 0x0fffff, NetS(h->length));
 	v6hdr_seprint(m);
 	return 0;
 }