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Revision 2fdba6b085eb7068e9594cfa55ffe40466184b4d authored by Herbert Xu on 19 May 2005, 05:52:33 UTC, committed by David S. Miller on 19 May 2005, 05:52:33 UTC 
[IPV4/IPV6] Ensure all frag_list members have NULL sk
 
Having frag_list members which holds wmem of an sk leads to nightmares
with partially cloned frag skb's.  The reason is that once you unleash
a skb with a frag_list that has individual sk ownerships into the stack
you can never undo those ownerships safely as they may have been cloned
by things like netfilter.  Since we have to undo them in order to make
skb_linearize happy this approach leads to a dead-end.

So let's go the other way and make this an invariant:

	For any skb on a frag_list, skb->sk must be NULL.

That is, the socket ownership always belongs to the head skb.
It turns out that the implementation is actually pretty simple.

The above invariant is actually violated in the following patch
for a short duration inside ip_fragment.  This is OK because the
offending frag_list member is either destroyed at the end of the
slow path without being sent anywhere, or it is detached from
the frag_list before being sent.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Kconfig 
#
# Library configuration
#

menu "Library routines"

config CRC_CCITT
	tristate "CRC-CCITT functions"
	help
	  This option is provided for the case where no in-kernel-tree
	  modules require CRC-CCITT functions, but a module built outside
	  the kernel tree does. Such modules that use library CRC-CCITT
	  functions require M here.

config CRC32
	tristate "CRC32 functions"
	default y
	help
	  This option is provided for the case where no in-kernel-tree
	  modules require CRC32 functions, but a module built outside the
	  kernel tree does. Such modules that use library CRC32 functions
	  require M here.

config LIBCRC32C
	tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check"
	help
	  This option is provided for the case where no in-kernel-tree
	  modules require CRC32c functions, but a module built outside the
	  kernel tree does. Such modules that use library CRC32c functions
	  require M here.  See Castagnoli93.
	  Module will be libcrc32c.

#
# compression support is select'ed if needed
#
config ZLIB_INFLATE
	tristate

config ZLIB_DEFLATE
	tristate

#
# reed solomon support is select'ed if needed
#
config REED_SOLOMON
	tristate
	
config REED_SOLOMON_ENC8
	boolean

config REED_SOLOMON_DEC8
	boolean

config REED_SOLOMON_ENC16
	boolean

config REED_SOLOMON_DEC16
	boolean

endmenu
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