commit 839c8456fbe08fc2497857673805b84dffb45507
author Jussi Kivilinna <jussi.kivilinna@mbnet.fi> Fri Jul 25 16:19:09 2008 +0300
committer Stephen Hemminger <stephen.hemminger@vyatta.com> Wed Sep 17 21:57:15 2008 -0700
tree 0a673737abcf67d411dcd06e3cda079c7a3ab967
parent 47420640687cbd389ddd99d39cf7fb0e0bcb265a

add generic size table for qdiscs

Patch adds generic size table that is similiar to rate table, with
difference that size table stores link layer packet size.

Based on patch by Patrick McHardy
 http://marc.info/?l=linux-netdev&m=115201979221729&w=2

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: Stephen Hemminger <stephen.hemminger@vyatta.com>

tc/tc_core.c

diff --git a/tc/tc_core.c b/tc/tc_core.c
index 855c115..9a0ff39 100644
--- a/tc/tc_core.c
+++ b/tc/tc_core.c
@@ -87,6 +87,21 @@
 	return linksize;
 }
 
+unsigned tc_adjust_size(unsigned sz, unsigned mpu, enum link_layer linklayer)
+{
+	if (sz < mpu)
+		sz = mpu;
+
+	switch (linklayer) {
+	case LINKLAYER_ATM:
+		return tc_align_to_atm(sz);
+	case LINKLAYER_ETHERNET:
+	default:
+		// No size adjustments on Ethernet
+		return sz;
+	}
+}
+
 /*
    rtab[pkt_len>>cell_log] = pkt_xmit_time
  */
@@ -96,6 +111,7 @@
 		   enum link_layer linklayer)
 {
 	int i;
+	unsigned sz;
 	unsigned bps = r->rate;
 	unsigned mpu = r->mpu;
 
@@ -109,21 +125,7 @@
 	}
 
 	for (i=0; i<256; i++) {
-		unsigned sz = (i+1)<<cell_log;
-		if (sz < mpu)
-			sz = mpu;
-
-		switch (linklayer) {
-		case LINKLAYER_ATM:
-			sz = tc_align_to_atm(sz);
-			break;
-		case LINKLAYER_ETHERNET:
-			// No size adjustments on Ethernet
-			break;
-		default:
-			break;
-		}
-
+		sz = tc_adjust_size((i + 1) << cell_log, mpu, linklayer);
 		rtab[i] = tc_calc_xmittime(bps, sz);
 	}
 
@@ -132,6 +134,53 @@
 	return cell_log;
 }
 
+/*
+   stab[pkt_len>>cell_log] = pkt_xmit_size>>size_log
+ */
+
+int tc_calc_size_table(struct tc_sizespec *s, __u16 **stab)
+{
+	int i;
+	enum link_layer linklayer = s->linklayer;
+	unsigned int sz;
+
+	if (linklayer <= LINKLAYER_ETHERNET && s->mpu == 0) {
+		/* don't need data table in this case (only overhead set) */
+		s->mtu = 0;
+		s->tsize = 0;
+		s->cell_log = 0;
+		s->cell_align = 0;
+		*stab = NULL;
+		return 0;
+	}
+
+	if (s->mtu == 0)
+		s->mtu = 2047;
+	if (s->tsize == 0)
+		s->tsize = 512;
+
+	s->cell_log = 0;
+	while ((s->mtu >> s->cell_log) > s->tsize - 1)
+		s->cell_log++;
+
+	*stab = malloc(s->tsize * sizeof(__u16));
+	if (!*stab)
+		return -1;
+
+again:
+	for (i = s->tsize - 1; i >= 0; i--) {
+		sz = tc_adjust_size((i + 1) << s->cell_log, s->mpu, linklayer);
+		if ((sz >> s->size_log) > UINT16_MAX) {
+			s->size_log++;
+			goto again;
+		}
+		(*stab)[i] = sz >> s->size_log;
+	}
+
+	s->cell_align = -1; // Due to the sz calc
+	return 0;
+}
+
 int tc_core_init()
 {
 	FILE *fp;