Re: [PATCH] expose simplified skb_checksum_recalc

2006-05-12 Thread David S. Miller
From: Stephen Hemminger [EMAIL PROTECTED]
Date: Thu, 11 May 2006 11:28:43 -0700

 Many users of skb_checksum_help() are just using it to recalculate
 outbound checksum, so why not expose the interface in a more useful
 way. Suggested by Ingo Oeser.
 
 Signed-off-by: Stephen Hemminger [EMAIL PROTECTED]

Since you will be adding the first users of skb_checksum_recalc(),
feel free to push this change in via your net driver tree whenever
you feel it is appropriate Stephen.

Thanks.
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[PATCH] expose simplified skb_checksum_recalc

2006-05-11 Thread Stephen Hemminger
Many users of skb_checksum_help() are just using it to recalculate
outbound checksum, so why not expose the interface in a more useful
way. Suggested by Ingo Oeser.

Signed-off-by: Stephen Hemminger [EMAIL PROTECTED]

--- linux-2.6.orig/include/linux/skbuff.h   2006-04-27 11:12:53.0 
-0700
+++ linux-2.6/include/linux/skbuff.h2006-05-11 11:17:39.0 -0700
@@ -1343,6 +1343,24 @@
__skb_checksum_complete(skb);
 }
 
+extern int skb_checksum_recalc(struct sk_buff *skb);
+/**
+ * skb_checksum_help - recalculate checksum of packet
+ * @skb: packet to process
+ * @inward: direction of flow, zero is receiving
+ *
+ * Invalidate hardware checksum when packet is to be mangled on
+ * receive and complete checksum manually on outgoing path.
+ */
+static inline int skb_checksum_help(struct sk_buff *skb, int inward)
+{
+   if (inward) {
+   skb-ip_summed = CHECKSUM_NONE;
+   return 0;
+   }
+   return skb_checksum_recalc(skb);
+}
+
 #ifdef CONFIG_NETFILTER
 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
 {
--- sky2.orig/net/core/dev.c2006-05-10 10:17:51.0 -0700
+++ sky2/net/core/dev.c 2006-05-11 11:22:27.0 -0700
@@ -1144,39 +1144,6 @@
 EXPORT_SYMBOL(netif_device_attach);
 
 
-/*
- * Invalidate hardware checksum when packet is to be mangled, and
- * complete checksum manually on outgoing path.
- */
-int skb_checksum_help(struct sk_buff *skb, int inward)
-{
-   unsigned int csum;
-   int ret = 0, offset = skb-h.raw - skb-data;
-
-   if (inward) {
-   skb-ip_summed = CHECKSUM_NONE;
-   goto out;
-   }
-
-   if (skb_cloned(skb)) {
-   ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
-   if (ret)
-   goto out;
-   }
-
-   BUG_ON(offset  (int)skb-len);
-   csum = skb_checksum(skb, offset, skb-len-offset, 0);
-
-   offset = skb-tail - skb-h.raw;
-   BUG_ON(offset = 0);
-   BUG_ON(skb-csum + 2  offset);
-
-   *(u16*)(skb-h.raw + skb-csum) = csum_fold(csum);
-   skb-ip_summed = CHECKSUM_NONE;
-out:   
-   return ret;
-}
-
 /* Take action when hardware reception checksum errors are detected. */
 #ifdef CONFIG_BUG
 void netdev_rx_csum_fault(struct net_device *dev)
@@ -3403,7 +3370,6 @@
 EXPORT_SYMBOL(register_gifconf);
 EXPORT_SYMBOL(register_netdevice);
 EXPORT_SYMBOL(register_netdevice_notifier);
-EXPORT_SYMBOL(skb_checksum_help);
 EXPORT_SYMBOL(synchronize_net);
 EXPORT_SYMBOL(unregister_netdevice);
 EXPORT_SYMBOL(unregister_netdevice_notifier);
--- sky2.orig/net/core/skbuff.c 2006-04-27 11:12:54.0 -0700
+++ sky2/net/core/skbuff.c  2006-05-11 11:23:13.0 -0700
@@ -1334,6 +1334,36 @@
 }
 
 /**
+ * skb_checksum_recalc - force software checksum
+ * @skb: skb to process
+ * Force complete checksum, this is used to force a software checksum
+ * on the outgoing path.
+ */
+int skb_checksum_recalc(struct sk_buff *skb)
+{
+   unsigned int csum;
+   int ret = 0, offset = skb-h.raw - skb-data;
+
+   if (skb_cloned(skb)) {
+   ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
+   if (ret)
+   goto out;
+   }
+
+   BUG_ON(offset  (int)skb-len);
+   csum = skb_checksum(skb, offset, skb-len-offset, 0);
+
+   offset = skb-tail - skb-h.raw;
+   BUG_ON(offset = 0);
+   BUG_ON(skb-csum + 2  offset);
+
+   *(u16*)(skb-h.raw + skb-csum) = csum_fold(csum);
+   skb-ip_summed = CHECKSUM_NONE;
+out:
+   return ret;
+}
+
+/**
  * skb_dequeue - remove from the head of the queue
  * @list: list to dequeue from
  *
@@ -1854,6 +1884,7 @@
 EXPORT_SYMBOL(pskb_copy);
 EXPORT_SYMBOL(pskb_expand_head);
 EXPORT_SYMBOL(skb_checksum);
+EXPORT_SYMBOL(skb_checksum_recalc);
 EXPORT_SYMBOL(skb_clone);
 EXPORT_SYMBOL(skb_clone_fraglist);
 EXPORT_SYMBOL(skb_copy);
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Re: [PATCH] expose simplified skb_checksum_recalc

2006-05-11 Thread Ingo Oeser
Hi Stephen,

Stephen Hemminger wrote:
 Many users of skb_checksum_help() are just using it to recalculate
 outbound checksum, so why not expose the interface in a more useful
 way. Suggested by Ingo Oeser.

You are damn fast Stephen :-)

That's even better and improves a lot on documentation and
code placement for free.


Thanks  Regards

Ingo Oeser
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