[PATCH 2/2] [SKBUFF] introduce tr_hdr(skb)

[PATCH 2/2] [SKBUFF] introduce tr_hdr(skb)

[Arnaldo Carvalho de Melo]

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Hi David,
	

	Please consider pulling from:

bk://kernel.bkbits.net/acme/sk_buff-2.6

Regards,

- Arnaldo

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===================================================================


ChangeSet@1.2056, 2004-10-06 15:33:22-03:00, acme@conectiva.com.br
  [SKBUFF] introduce tr_hdr(skb)
  
  The token ring code in the kernel is bitrotting (no surprise :) ),
  it uses skb->data all around... I have an assortment of token ring
  cards but no MAU, can anybody send me one, please? I promise to
  make ssh work over LLC over Token Ring networks! Duh... :o)
  
  Signed-off-by: Arnaldo Carvalho de Melo <acme@conectiva.com.br>
  Signed-off-by: David S. Miller <davem@redhat.com>


 include/linux/if_tr.h |    9 +++++++++
 include/net/llc_pdu.h |    4 ++--
 net/llc/llc_output.c  |    4 ++--
 3 files changed, 13 insertions(+), 4 deletions(-)


diff -Nru a/include/linux/if_tr.h b/include/linux/if_tr.h
--- a/include/linux/if_tr.h	2004-10-06 15:34:53 -03:00
+++ b/include/linux/if_tr.h	2004-10-06 15:34:53 -03:00
@@ -48,6 +48,15 @@
 	__u16 rseg[8];			/* routing registers */
 };
 
+#ifdef __KERNEL__
+#include <linux/skbuff.h>
+
+static inline struct trh_hdr *tr_hdr(const struct sk_buff *skb)
+{
+	return (struct trh_hdr *)skb->mac.raw;
+}
+#endif
+
 /* This is an Token-Ring LLC structure */
 struct trllc {
 	__u8  dsap;			/* destination SAP */
diff -Nru a/include/net/llc_pdu.h b/include/net/llc_pdu.h
--- a/include/net/llc_pdu.h	2004-10-06 15:34:53 -03:00
+++ b/include/net/llc_pdu.h	2004-10-06 15:34:53 -03:00
@@ -255,7 +255,7 @@
 	if (skb->protocol == ntohs(ETH_P_802_2))
 		memcpy(sa, eth_hdr(skb)->h_source, ETH_ALEN);
 	else if (skb->protocol == ntohs(ETH_P_TR_802_2))
-		memcpy(sa, ((struct trh_hdr *)skb->mac.raw)->saddr, ETH_ALEN);
+		memcpy(sa, tr_hdr(skb)->saddr, ETH_ALEN);
 }
 
 /**
@@ -270,7 +270,7 @@
 	if (skb->protocol == ntohs(ETH_P_802_2))
 		memcpy(da, eth_hdr(skb)->h_dest, ETH_ALEN);
 	else if (skb->protocol == ntohs(ETH_P_TR_802_2))
-		memcpy(da, ((struct trh_hdr *)skb->mac.raw)->daddr, ETH_ALEN);
+		memcpy(da, tr_hdr(skb)->daddr, ETH_ALEN);
 }
 
 /**
diff -Nru a/net/llc/llc_output.c b/net/llc/llc_output.c
--- a/net/llc/llc_output.c	2004-10-06 15:34:53 -03:00
+++ b/net/llc/llc_output.c	2004-10-06 15:34:53 -03:00
@@ -40,7 +40,8 @@
 		struct net_device *dev = skb->dev;
 		struct trh_hdr *trh;
 		
-		trh = (struct trh_hdr *)skb_push(skb, sizeof(*trh));
+		skb->mac.raw = skb_push(skb, sizeof(*trh));
+		trh = tr_hdr(skb);
 		trh->ac = AC;
 		trh->fc = LLC_FRAME;
 		if (sa)
@@ -51,7 +52,6 @@
 			memcpy(trh->daddr, da, dev->addr_len);
 			tr_source_route(skb, trh, dev);
 		}
-		skb->mac.raw = skb->data;
 		break;
 	}
 #endif

Re: [PATCH 2/2] [SKBUFF] introduce tr_hdr(skb)

[Thomas Graf]

* Arnaldo Carvalho de Melo <41643C40.8070605@conectiva.com.br> 2004-10-06 15:41
> -		trh = (struct trh_hdr *)skb_push(skb, sizeof(*trh));
> +		skb->mac.raw = skb_push(skb, sizeof(*trh));
> +		trh = tr_hdr(skb);
>  		trh->ac = AC;
>  		trh->fc = LLC_FRAME;
>  		if (sa)
> @@ -51,7 +52,6 @@
>  			memcpy(trh->daddr, da, dev->addr_len);
>  			tr_source_route(skb, trh, dev);
>  		}
> -		skb->mac.raw = skb->data;

Are you sure the bevhaviour is the same? There is an skb_pull
in tr_source_route so skb->data gets modified. 

Re: [PATCH 2/2] [SKBUFF] introduce tr_hdr(skb)

[Arnaldo Carvalho de Melo]

Thomas Graf wrote:
> * Arnaldo Carvalho de Melo <41643C40.8070605@conectiva.com.br> 2004-10-06 15:41
> 
>>-		trh = (struct trh_hdr *)skb_push(skb, sizeof(*trh));
>>+		skb->mac.raw = skb_push(skb, sizeof(*trh));
>>+		trh = tr_hdr(skb);
>> 		trh->ac = AC;
>> 		trh->fc = LLC_FRAME;
>> 		if (sa)
>>@@ -51,7 +52,6 @@
>> 			memcpy(trh->daddr, da, dev->addr_len);
>> 			tr_source_route(skb, trh, dev);
>> 		}
>>-		skb->mac.raw = skb->data;
> 
> 
> Are you sure the bevhaviour is the same? There is an skb_pull
> in tr_source_route so skb->data gets modified. 
> 
> 


Thanks for reviewing, checking...

Re: [PATCH 2/2] [SKBUFF] introduce tr_hdr(skb)

[David S. Miller]

On Wed, 06 Oct 2004 16:18:49 -0300
Arnaldo Carvalho de Melo <acme@conectiva.com.br> wrote:

> You're right, if tr_source_route is called, skb->mac.raw has to be set
> to skb->data, to maintain the old behaviour, if it is right?

Yep.

Re: [PATCH 2/2] [SKBUFF] introduce tr_hdr(skb)

[Arnaldo Carvalho de Melo]

Arnaldo Carvalho de Melo wrote:
> 
> 
> Thomas Graf wrote:
> 
>> * Arnaldo Carvalho de Melo <41643C40.8070605@conectiva.com.br> 
>> 2004-10-06 15:41
>>
>>> -        trh = (struct trh_hdr *)skb_push(skb, sizeof(*trh));
>>> +        skb->mac.raw = skb_push(skb, sizeof(*trh));
>>> +        trh = tr_hdr(skb);
>>>         trh->ac = AC;
>>>         trh->fc = LLC_FRAME;
>>>         if (sa)
>>> @@ -51,7 +52,6 @@
>>>             memcpy(trh->daddr, da, dev->addr_len);
>>>             tr_source_route(skb, trh, dev);
>>>         }
>>> -        skb->mac.raw = skb->data;
>>
>>
>>
>> Are you sure the bevhaviour is the same? There is an skb_pull
>> in tr_source_route so skb->data gets modified.
>>
> 
> 
> Thanks for reviewing, checking...
> 
> 

You're right, if tr_source_route is called, skb->mac.raw has to be set
to skb->data, to maintain the old behaviour, if it is right? Oh well,
as I said there aren't many people using Token Ring, let alone LLC over
token ring, I'll be posting a patch in some minutes.

- Arnaldo