On Wed, Aug 20, 2003 at 08:16:29AM -0700, David S. Miller wrote:
>
> And the idea is to replace all of the:
>
> skb_push(skb, skb->data - skb->mac.raw);
>
> with:
>
> skb_push(skb, skb->maclen);
>
> Right?
Eventually yes.
> Sounds interesting. There are a few issues.
>
> 1) packet socket will still need to do the memmove()
> 2) getting ->maclen set correctly in all cases might
> get tricky
>
> For #2 it might be simpler to only use skb->maclen when
> skb->dev is NULL.
>
> What do you think?
Actually if we require that upon entry into netif_rx that
skb->nh.raw and skb->mac.raw are set correctly and are next
to each other, then we can avoid having to get mac_len right.
This is what the following patch does.
Cheers,
--
Debian GNU/Linux 3.0 is out! ( http://www.debian.org/ )
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
Index: include/linux/skbuff.h
===================================================================
RCS file: /home/gondolin/herbert/src/CVS/debian/kernel-source-2.5/include/linux/skbuff.h,v
retrieving revision 1.1.1.8
retrieving revision 1.6
diff -u -r1.1.1.8 -r1.6
--- include/linux/skbuff.h 9 Aug 2003 08:12:03 -0000 1.1.1.8
+++ include/linux/skbuff.h 13 Sep 2003 00:11:55 -0000 1.6
@@ -159,6 +161,7 @@
* @cb: Control buffer. Free for use by every layer. Put private vars here
* @len: Length of actual data
* @data_len: Data length
+ * @mac_len: Length of link layer header
* @csum: Checksum
* @__unused: Dead field, may be reused
* @cloned: Head may be cloned (check refcnt to be sure)
@@ -199,6 +202,7 @@
struct icmphdr *icmph;
struct igmphdr *igmph;
struct iphdr *ipiph;
+ struct ipv6hdr *ipv6h;
unsigned char *raw;
} h;
@@ -227,6 +231,7 @@
unsigned int len,
data_len,
+ mac_len,
csum;
unsigned char local_df,
cloned,
Index: net/core/dev.c
===================================================================
RCS file: /home/gondolin/herbert/src/CVS/debian/kernel-source-2.5/net/core/dev.c,v
retrieving revision 1.1.1.17
retrieving revision 1.2
diff -u -r1.1.1.17 -r1.2
--- net/core/dev.c 22 Aug 2003 23:56:14 -0000 1.1.1.17
+++ net/core/dev.c 13 Sep 2003 00:11:55 -0000 1.2
@@ -1547,6 +1547,7 @@
#endif
skb->h.raw = skb->nh.raw = skb->data;
+ skb->mac_len = skb->nh.raw - skb->mac.raw;
pt_prev = NULL;
rcu_read_lock();
Index: net/ipv4/xfrm4_input.c
===================================================================
RCS file: /home/gondolin/herbert/src/CVS/debian/kernel-source-2.5/net/ipv4/xfrm4_input.c,v
retrieving revision 1.1.1.6
retrieving revision 1.9
diff -u -r1.1.1.6 -r1.9
--- net/ipv4/xfrm4_input.c 22 Aug 2003 23:52:18 -0000 1.1.1.6
+++ net/ipv4/xfrm4_input.c 13 Sep 2003 00:11:55 -0000 1.9
@@ -9,6 +9,7 @@
*
*/
+#include <linux/string.h>
#include <net/inet_ecn.h>
#include <net/ip.h>
#include <net/xfrm.h>
@@ -18,9 +19,10 @@
return xfrm4_rcv_encap(skb, 0);
}
-static inline void ipip_ecn_decapsulate(struct iphdr *outer_iph, struct sk_buff *skb)
+static inline void ipip_ecn_decapsulate(struct sk_buff *skb)
{
- struct iphdr *inner_iph = skb->nh.iph;
+ struct iphdr *outer_iph = skb->nh.iph;
+ struct iphdr *inner_iph = skb->h.ipiph;
if (INET_ECN_is_ce(outer_iph->tos) &&
INET_ECN_is_not_ce(inner_iph->tos))
@@ -95,10 +97,16 @@
if (x->props.mode) {
if (iph->protocol != IPPROTO_IPIP)
goto drop;
- skb->nh.raw = skb->data;
+ if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+ goto drop;
+ if (skb_cloned(skb) &&
+ pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+ goto drop;
if (!(x->props.flags & XFRM_STATE_NOECN))
- ipip_ecn_decapsulate(iph, skb);
- iph = skb->nh.iph;
+ ipip_ecn_decapsulate(skb);
+ skb->mac.raw = memmove(skb->data - skb->mac_len,
+ skb->mac.raw, skb->mac_len);
+ skb->nh.raw = skb->data;
memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options));
decaps = 1;
break;
Index: net/ipv6/xfrm6_input.c
===================================================================
RCS file: /home/gondolin/herbert/src/CVS/debian/kernel-source-2.5/net/ipv6/xfrm6_input.c,v
retrieving revision 1.1.1.7
retrieving revision 1.8
diff -u -r1.1.1.7 -r1.8
--- net/ipv6/xfrm6_input.c 9 Aug 2003 08:12:04 -0000 1.1.1.7
+++ net/ipv6/xfrm6_input.c 13 Sep 2003 00:11:55 -0000 1.8
@@ -9,17 +9,20 @@
* IPv6 support
*/
+#include <linux/string.h>
#include <net/inet_ecn.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/xfrm.h>
-static inline void ipip6_ecn_decapsulate(struct ipv6hdr *iph,
- struct sk_buff *skb)
+static inline void ipip6_ecn_decapsulate(struct sk_buff *skb)
{
- if (INET_ECN_is_ce(ip6_get_dsfield(iph)) &&
- INET_ECN_is_not_ce(ip6_get_dsfield(skb->nh.ipv6h)))
- IP6_ECN_set_ce(skb->nh.ipv6h);
+ struct ipv6hdr *outer_iph = skb->nh.ipv6h;
+ struct ipv6hdr *inner_iph = skb->h.ipv6h;
+
+ if (INET_ECN_is_ce(ip6_get_dsfield(outer_iph)) &&
+ INET_ECN_is_not_ce(ip6_get_dsfield(inner_iph)))
+ IP6_ECN_set_ce(inner_iph);
}
int xfrm6_rcv(struct sk_buff **pskb, unsigned int *nhoffp)
@@ -77,10 +80,16 @@
if (x->props.mode) { /* XXX */
if (nexthdr != IPPROTO_IPV6)
goto drop;
- skb->nh.raw = skb->data;
+ if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
+ goto drop;
+ if (skb_cloned(skb) &&
+ pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+ goto drop;
if (!(x->props.flags & XFRM_STATE_NOECN))
- ipip6_ecn_decapsulate(iph, skb);
- iph = skb->nh.ipv6h;
+ ipip6_ecn_decapsulate(skb);
+ skb->mac.raw = memmove(skb->data - skb->mac_len,
+ skb->mac.raw, skb->mac_len);
+ skb->nh.raw = skb->data;
decaps = 1;
break;
}
