From: Herbert Xu <herbert@gondor.apana.org.au>
To: David Miller <davem@davemloft.net>
Cc: pupilla@hotmail.com, linux-kernel@vger.kernel.org,
netdev@vger.kernel.org
Subject: ipsec: ipcomp - Decompress into frags if necessary
Date: Fri, 25 Jul 2008 15:43:28 +0800 [thread overview]
Message-ID: <20080725074328.GB16747@gondor.apana.org.au> (raw)
In-Reply-To: <20080725074109.GA16747@gondor.apana.org.au>
On Fri, Jul 25, 2008 at 03:41:09PM +0800, Herbert Xu wrote:
>
> Here is the first part:
And finally:
ipsec: ipcomp - Decompress into frags if necessary
When decompressing extremely large packets allocating them through
kmalloc is prone to failure. Therefore it's better to use page
frags instead.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/net/xfrm/xfrm_ipcomp.c b/net/xfrm/xfrm_ipcomp.c
index b51e804..800f669 100644
--- a/net/xfrm/xfrm_ipcomp.c
+++ b/net/xfrm/xfrm_ipcomp.c
@@ -17,6 +17,7 @@
#include <linux/crypto.h>
#include <linux/err.h>
+#include <linux/gfp.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
@@ -49,6 +50,7 @@ static int ipcomp_decompress(struct xfrm_state *x, struct sk_buff *skb)
u8 *scratch = *per_cpu_ptr(ipcomp_scratches, cpu);
struct crypto_comp *tfm = *per_cpu_ptr(ipcd->tfms, cpu);
int err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen);
+ int len;
if (err)
goto out;
@@ -58,13 +60,47 @@ static int ipcomp_decompress(struct xfrm_state *x, struct sk_buff *skb)
goto out;
}
- err = pskb_expand_head(skb, 0, dlen - plen, GFP_ATOMIC);
- if (err)
- goto out;
+ len = dlen - plen;
+ if (len > skb_tailroom(skb))
+ len = skb_tailroom(skb);
+
+ skb->truesize += len;
+ __skb_put(skb, len);
+
+ len += plen;
+ skb_copy_to_linear_data(skb, scratch, len);
+
+ while ((scratch += len, dlen -= len) > 0) {
+ skb_frag_t *frag;
+
+ err = -EMSGSIZE;
+ if (WARN_ON(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS))
+ goto out;
+
+ frag = skb_shinfo(skb)->frags + skb_shinfo(skb)->nr_frags;
+ frag->page = alloc_page(GFP_ATOMIC);
+
+ err = -ENOMEM;
+ if (!frag->page)
+ goto out;
+
+ len = PAGE_SIZE;
+ if (dlen < len)
+ len = dlen;
+
+ memcpy(page_address(frag->page), scratch, len);
+
+ frag->page_offset = 0;
+ frag->size = len;
+ skb->truesize += len;
+ skb->data_len += len;
+ skb->len += len;
+
+ skb_shinfo(skb)->nr_frags++;
+ }
+
+ err = 0;
- skb->truesize += dlen - plen;
- __skb_put(skb, dlen - plen);
- skb_copy_to_linear_data(skb, scratch, dlen);
out:
put_cpu();
return err;
Cheers,
--
Visit Openswan at http://www.openswan.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
next prev parent reply other threads:[~2008-07-25 7:44 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-07-24 6:39 2.6.26: [<c0133cc1>] __alloc_pages_internal+0x331/0x343 Marco Berizzi
2008-07-24 6:45 ` David Miller
2008-07-24 13:06 ` Herbert Xu
2008-07-25 7:41 ` Herbert Xu
2008-07-25 7:43 ` Herbert Xu [this message]
2008-07-25 9:58 ` ipsec: ipcomp - Decompress into frags if necessary David Miller
2008-07-25 10:46 ` Herbert Xu
2008-07-25 10:55 ` David Miller
2008-07-25 9:54 ` 2.6.26: [<c0133cc1>] __alloc_pages_internal+0x331/0x343 David Miller
2008-07-24 15:06 ` Marco Berizzi
2008-07-25 14:18 ` Herbert Xu
2008-07-25 14:19 ` Herbert Xu
2008-07-25 19:19 ` Marco Berizzi
2008-07-25 20:12 ` David Miller
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