Commit c020b9d4 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'inet_csums' 



Tom Herbert says:

====================
net: Checksum offload changes

I am working on overhauling RX checksum offload. Goals of this effort
are:

- Specify what exactly it means when driver returns CHECKSUM_UNNECESSARY
- Preserve CHECKSUM_COMPLETE through encapsulation layers
- Don't do skb_checksum more than once per packet
- Unify GRO and non-GRO csum verification as much as possible
- Unify the checksum functions (checksum_init)
- Simply code

What is in this first patch set:

- Create a common "checksum_init" function which is called from
  TCPv{4,6} and UDPv{4,6}
- Add some for RFC6936, UDP/IPv6 zero checksums
- Add architecture support for csum_add and provide implementations
  for x86_64 and Sparc 32 and 64 bit (please test the latter)

Please review carefully and test if possible, mucking with basic
checksum functions is always a little precarious :-)
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 2ad06496 4068579e

arch/sparc/include/asm/checksum_32.h

+12 −0
Original line number Diff line number Diff line
@@ -238,4 +238,16 @@ static inline __sum16 ip_compute_csum(const void *buff, int len) 
	return csum_fold(csum_partial(buff, len, 0));

}



#define HAVE_ARCH_CSUM_ADD

static inline __wsum csum_add(__wsum csum, __wsum addend)

{

	__asm__ __volatile__(

		"addcc   %0, %1, %0\n"

		"addx    %0, %%g0, %0"

		: "=r" (csum)

		: "r" (addend), "0" (csum));



	return csum;

}



#endif /* !(__SPARC_CHECKSUM_H) */

arch/sparc/include/asm/checksum_64.h

+12 −0
Original line number Diff line number Diff line
@@ -164,4 +164,16 @@ static inline __sum16 ip_compute_csum(const void *buff, int len) 
	return csum_fold(csum_partial(buff, len, 0));

}



#define HAVE_ARCH_CSUM_ADD

static inline __wsum csum_add(__wsum csum, __wsum addend)

{

	__asm__ __volatile__(

		"addcc   %0, %1, %0\n"

		"addx    %0, %%g0, %0"

		: "=r" (csum)

		: "r" (addend), "0" (csum));



	return csum;

}



#endif /* !(__SPARC64_CHECKSUM_H) */

arch/x86/include/asm/checksum_64.h

+8 −1
Original line number Diff line number Diff line
@@ -184,8 +184,15 @@ static inline unsigned add32_with_carry(unsigned a, unsigned b) 
	asm("addl %2,%0\n\t"

	    "adcl $0,%0"

	    : "=r" (a)

	    : "0" (a), "r" (b));

	    : "0" (a), "rm" (b));

	return a;

}



#define HAVE_ARCH_CSUM_ADD

static inline __wsum csum_add(__wsum csum, __wsum addend)

{

	return (__force __wsum)add32_with_carry((__force unsigned)csum,

						(__force unsigned)addend);

}



#endif /* _ASM_X86_CHECKSUM_64_H */

include/linux/skbuff.h

+93 −0
Original line number Diff line number Diff line
@@ -2741,6 +2741,99 @@ static inline __sum16 skb_checksum_complete(struct sk_buff *skb) 
	       0 : __skb_checksum_complete(skb);

}



/* Check if we need to perform checksum complete validation.

 *

 * Returns true if checksum complete is needed, false otherwise

 * (either checksum is unnecessary or zero checksum is allowed).

 */

static inline bool __skb_checksum_validate_needed(struct sk_buff *skb,

						  bool zero_okay,

						  __sum16 check)

{

	if (skb_csum_unnecessary(skb)) {

		return false;

	} else if (zero_okay && !check) {

		skb->ip_summed = CHECKSUM_UNNECESSARY;

		return false;

	}



	return true;

}



/* For small packets <= CHECKSUM_BREAK peform checksum complete directly

 * in checksum_init.

 */

#define CHECKSUM_BREAK 76



/* Validate (init) checksum based on checksum complete.

 *

 * Return values:

 *   0: checksum is validated or try to in skb_checksum_complete. In the latter

 *	case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo

 *	checksum is stored in skb->csum for use in __skb_checksum_complete

 *   non-zero: value of invalid checksum

 *

 */

static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb,

						       bool complete,

						       __wsum psum)

{

	if (skb->ip_summed == CHECKSUM_COMPLETE) {

		if (!csum_fold(csum_add(psum, skb->csum))) {

			skb->ip_summed = CHECKSUM_UNNECESSARY;

			return 0;

		}

	}



	skb->csum = psum;



	if (complete || skb->len <= CHECKSUM_BREAK)

		return __skb_checksum_complete(skb);



	return 0;

}



static inline __wsum null_compute_pseudo(struct sk_buff *skb, int proto)

{

	return 0;

}



/* Perform checksum validate (init). Note that this is a macro since we only

 * want to calculate the pseudo header which is an input function if necessary.

 * First we try to validate without any computation (checksum unnecessary) and

 * then calculate based on checksum complete calling the function to compute

 * pseudo header.

 *

 * Return values:

 *   0: checksum is validated or try to in skb_checksum_complete

 *   non-zero: value of invalid checksum

 */

#define __skb_checksum_validate(skb, proto, complete,			\

				zero_okay, check, compute_pseudo)	\

({									\

	__sum16 __ret = 0;						\

	if (__skb_checksum_validate_needed(skb, zero_okay, check))	\

		__ret = __skb_checksum_validate_complete(skb,		\

				complete, compute_pseudo(skb, proto));	\

	__ret;								\

})



#define skb_checksum_init(skb, proto, compute_pseudo)			\

	__skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)



#define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo)	\

	__skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)



#define skb_checksum_validate(skb, proto, compute_pseudo)		\

	__skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)



#define skb_checksum_validate_zero_check(skb, proto, check,		\

					 compute_pseudo)		\

	__skb_checksum_validate_(skb, proto, true, true, check, compute_pseudo)



#define skb_checksum_simple_validate(skb)				\

	__skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)



#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)

void nf_conntrack_destroy(struct nf_conntrack *nfct);

static inline void nf_conntrack_put(struct nf_conntrack *nfct)

include/net/checksum.h

+2 −0
Original line number Diff line number Diff line
@@ -57,12 +57,14 @@ static __inline__ __wsum csum_and_copy_to_user 
}

#endif



#ifndef HAVE_ARCH_CSUM_ADD

static inline __wsum csum_add(__wsum csum, __wsum addend)

{

	u32 res = (__force u32)csum;

	res += (__force u32)addend;

	return (__force __wsum)(res + (res < (__force u32)addend));

}

#endif



static inline __wsum csum_sub(__wsum csum, __wsum addend)

{

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