Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
authored by
Herbert Xu
and committed by
David S. Miller
7d7e5a60
6fccab67
+42
-6
net/xfrm/xfrm_ipcomp.c
+42
-6
net/xfrm/xfrm_ipcomp.c
···
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#include <linux/crypto.h>
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#include <linux/err.h>
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#include <linux/list.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
···
50
u8 *scratch = *per_cpu_ptr(ipcomp_scratches, cpu);
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struct crypto_comp *tfm = *per_cpu_ptr(ipcd->tfms, cpu);
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int err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen);
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if (err)
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goto out;
···
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goto out;
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}
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-
err = pskb_expand_head(skb, 0, dlen - plen, GFP_ATOMIC);
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-
if (err)
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-
goto out;
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skb->truesize += dlen - plen;
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-
__skb_put(skb, dlen - plen);
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-
skb_copy_to_linear_data(skb, scratch, dlen);
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out:
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put_cpu();
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return err;
···
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#include <linux/crypto.h>
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#include <linux/err.h>
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+
#include <linux/gfp.h>
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#include <linux/list.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
···
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u8 *scratch = *per_cpu_ptr(ipcomp_scratches, cpu);
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struct crypto_comp *tfm = *per_cpu_ptr(ipcd->tfms, cpu);
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int err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen);
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+
int len;
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if (err)
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goto out;
···
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goto out;
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}
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+
len = dlen - plen;
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+
if (len > skb_tailroom(skb))
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+
len = skb_tailroom(skb);
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+
skb->truesize += len;
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+
__skb_put(skb, len);
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+
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len += plen;
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+
skb_copy_to_linear_data(skb, scratch, len);
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+
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+
while ((scratch += len, dlen -= len) > 0) {
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+
skb_frag_t *frag;
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+
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+
err = -EMSGSIZE;
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+
if (WARN_ON(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS))
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+
goto out;
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+
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frag = skb_shinfo(skb)->frags + skb_shinfo(skb)->nr_frags;
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+
frag->page = alloc_page(GFP_ATOMIC);
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+
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err = -ENOMEM;
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+
if (!frag->page)
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+
goto out;
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+
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+
len = PAGE_SIZE;
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+
if (dlen < len)
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len = dlen;
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+
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+
memcpy(page_address(frag->page), scratch, len);
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+
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frag->page_offset = 0;
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+
frag->size = len;
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skb->truesize += len;
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skb->data_len += len;
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+
skb->len += len;
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+
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+
skb_shinfo(skb)->nr_frags++;
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+
}
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+
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+
err = 0;
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+
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out:
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put_cpu();
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return err;