[PATCH] ethernet-bridge: update skb->priority in case forwarded frame has VLAN-header

From: Leo Yuriev
Date: Sat Mar 05 2005 - 09:02:32 EST


Kernel 2.6 (2.6.11)

When ethernet-bridge forward a packet and such ethernet-frame has
VLAN-tag, bridge should update skb->prioriry for properly QoS
handling.

This small patch does this. Currently vlan_TCI-priority directly
mapped to skb->priority, but this looks enough.

Patch-by: Leo Yuriev <leo@xxxxxxxxx>


-- net/bridge/br_input.c.orig 2005-03-02 10:37:50.000000000 +0300
+++ net/bridge/br_input.c 2005-03-05 16:11:00.000000000 +0300
@@ -5,6 +5,10 @@
* Authors:
* Lennert Buytenhek <buytenh@xxxxxxx>
*
+ * Changes:
+ * 03/Mar/2005: Leo Yuriev <leo@xxxxxxxxx>
+ * Update skb->priority for packets with VLAN-tag.
+ *
* $Id: br_input.c,v 1.10 2001/12/24 04:50:20 davem Exp $
*
* This program is free software; you can redistribute it and/or
@@ -17,6 +21,9 @@
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/netfilter_bridge.h>
+#ifdef CONFIG_NET_SCHED
+# include <linux/if_vlan.h>
+#endif /* CONFIG_NET_SCHED*/
#include "br_private.h"

const unsigned char bridge_ula[6] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
@@ -45,6 +52,40 @@ static void br_pass_frame_up(struct net_
br_pass_frame_up_finish);
}

+
+#ifdef CONFIG_NET_SCHED
+/*
+ * Leo Yuriev: Just update skb->priority for properly QoS handling in case
+ * frame in the skb is contain VLAN-header.
+ *
+ * SANITY NOTE: We are referencing to the VLAN_HDR frields, which MAY be
+ * stored UNALIGNED in the memory.
+ * According to Dave Miller & Alexey, it will always be aligned,
+ * so there doesn't need to be any of the unaligned stuff.
+ *
+ */
+static __inline__ void br_update_skb_priority_if_vlan(struct sk_buff *skb)
+{
+ unsigned short vlan_TCI;
+ struct vlan_hdr *vhdr;
+
+ if (skb->protocol == __constant_htons(ETH_P_8021Q)) {
+ vhdr = (struct vlan_hdr *)(skb->data);
+ /* vlan_TCI = ntohs(get_unaligned(&vhdr->h_vlan_TCI)); */
+ vlan_TCI = ntohs(vhdr->h_vlan_TCI);
+#ifdef VLAN_DEBUG
+ printk(VLAN_DBG "%s: skb: %p vlan_id: %hx\n",
+ __FUNCTION__, skb, (vlan_TCI & VLAN_VID_MASK));
+#endif
+ /*
+ * We map VLAN_TCI priority (0..7) to skb->priority (0..15)
+ * most similarly e.g. 0->0, 1->1, .., 7->7
+ */
+ skb->priority = (vlan_TCI >> 13) & 7;
+ }
+}
+#endif /* CONFIG_NET_SCHED */
+
/* note: already called with rcu_read_lock (preempt_disabled) */
int br_handle_frame_finish(struct sk_buff *skb)
{
@@ -54,6 +95,10 @@ int br_handle_frame_finish(struct sk_buf
struct net_bridge_fdb_entry *dst;
int passedup = 0;

+#ifdef CONFIG_NET_SCHED
+ br_update_skb_priority_if_vlan(skb);
+#endif /* CONFIG_NET_SCHED*/
+
if (br->dev->flags & IFF_PROMISC) {
struct sk_buff *skb2;


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