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[v4,1/2] net: add functions to calculate UDP/TCP cksum in mbuf

Message ID 20211203113805.1025301-2-xiaoyun.li@intel.com (mailing list archive)
State Superseded
Delegated to: Ferruh Yigit
Headers show
Series Add functions to calculate UDP/TCP cksum in mbuf | expand

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Context Check Description
ci/checkpatch success coding style OK

Commit Message

Xiaoyun Li Dec. 3, 2021, 11:38 a.m. UTC
Add functions to call rte_raw_cksum_mbuf() to calculate IPv4/6
UDP/TCP checksum in mbuf which can be over multi-segments.

Signed-off-by: Xiaoyun Li <xiaoyun.li@intel.com>
---
 doc/guides/rel_notes/release_22_03.rst |  10 ++
 lib/net/rte_ip.h                       | 186 +++++++++++++++++++++++++
 lib/net/version.map                    |  10 ++
 3 files changed, 206 insertions(+)

Comments

Aman Singh Dec. 15, 2021, 11:33 a.m. UTC | #1
On 12/3/2021 5:08 PM, Xiaoyun Li wrote:
> Add functions to call rte_raw_cksum_mbuf() to calculate IPv4/6
> UDP/TCP checksum in mbuf which can be over multi-segments.
>
> Signed-off-by: Xiaoyun Li <xiaoyun.li@intel.com>
> ---
>   doc/guides/rel_notes/release_22_03.rst |  10 ++
>   lib/net/rte_ip.h                       | 186 +++++++++++++++++++++++++
>   lib/net/version.map                    |  10 ++
>   3 files changed, 206 insertions(+)
>
> diff --git a/doc/guides/rel_notes/release_22_03.rst b/doc/guides/rel_notes/release_22_03.rst
> index 6d99d1eaa9..7a082c4427 100644
> --- a/doc/guides/rel_notes/release_22_03.rst
> +++ b/doc/guides/rel_notes/release_22_03.rst
> @@ -55,6 +55,13 @@ New Features
>        Also, make sure to start the actual text at the margin.
>        =======================================================
>   
> +* **Added functions to calculate UDP/TCP checksum in mbuf.**
> +  * Added the following functions to calculate UDP/TCP checksum of packets
> +    which can be over multi-segments:
> +    - ``rte_ipv4_udptcp_cksum_mbuf()``
> +    - ``rte_ipv4_udptcp_cksum_mbuf_verify()``
> +    - ``rte_ipv6_udptcp_cksum_mbuf()``
> +    - ``rte_ipv6_udptcp_cksum_mbuf_verify()``
>   
>   Removed Items
>   -------------
> @@ -84,6 +91,9 @@ API Changes
>      Also, make sure to start the actual text at the margin.
>      =======================================================
>   
> +* net: added experimental functions ``rte_ipv4_udptcp_cksum_mbuf()``,
> +  ``rte_ipv4_udptcp_cksum_mbuf_verify()``, ``rte_ipv6_udptcp_cksum_mbuf()``,
> +  ``rte_ipv6_udptcp_cksum_mbuf_verify()``
>   
>   ABI Changes
>   -----------
> diff --git a/lib/net/rte_ip.h b/lib/net/rte_ip.h
> index c575250852..534f401d26 100644
> --- a/lib/net/rte_ip.h
> +++ b/lib/net/rte_ip.h
> @@ -400,6 +400,65 @@ rte_ipv4_udptcp_cksum(const struct rte_ipv4_hdr *ipv4_hdr, const void *l4_hdr)
>   	return cksum;
>   }
>   
> +/**
> + * @internal Calculate the non-complemented IPv4 L4 checksum of a packet
> + */
> +static inline uint16_t
> +__rte_ipv4_udptcp_cksum_mbuf(const struct rte_mbuf *m,
> +			     const struct rte_ipv4_hdr *ipv4_hdr,
> +			     uint16_t l4_off)
> +{
> +	uint16_t raw_cksum;
> +	uint32_t cksum;
> +
> +	if (l4_off > m->pkt_len)
> +		return 0;
> +
> +	if (rte_raw_cksum_mbuf(m, l4_off, m->pkt_len - l4_off, &raw_cksum))
> +		return 0;
> +
> +	cksum = raw_cksum + rte_ipv4_phdr_cksum(ipv4_hdr, 0);
> +
> +	cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
At times, even after above operation "cksum" might stay above 16-bits, 
ex "cksum = 0x1FFFF" to start with.
Can we consider using "return __rte_raw_cksum_reduce(cksum);"
> +
> +	return (uint16_t)cksum;
> +}
> +
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this API may change without prior notice.
> + *
> + * Compute the IPv4 UDP/TCP checksum of a packet.
> + *
> + * @param m
> + *   The pointer to the mbuf.
> + * @param ipv4_hdr
> + *   The pointer to the contiguous IPv4 header.
> + * @param l4_off
> + *   The offset in bytes to start L4 checksum.
> + * @return
> + *   The complemented checksum to set in the L4 header.
> + */
> +__rte_experimental
> +static inline uint16_t
> +rte_ipv4_udptcp_cksum_mbuf(const struct rte_mbuf *m,
> +			   const struct rte_ipv4_hdr *ipv4_hdr, uint16_t l4_off)
> +{
> +	uint16_t cksum = __rte_ipv4_udptcp_cksum_mbuf(m, ipv4_hdr, l4_off);
> +
> +	cksum = ~cksum;
> +
> +	/*
> +	 * Per RFC 768: If the computed checksum is zero for UDP,
> +	 * it is transmitted as all ones
> +	 * (the equivalent in one's complement arithmetic).
> +	 */
> +	if (cksum == 0 && ipv4_hdr->next_proto_id == IPPROTO_UDP)
> +		cksum = 0xffff;
> +
> +	return cksum;
> +}
> +
>   /**
>    * Validate the IPv4 UDP or TCP checksum.
>    *
> @@ -426,6 +485,38 @@ rte_ipv4_udptcp_cksum_verify(const struct rte_ipv4_hdr *ipv4_hdr,
>   	return 0;
>   }
>   
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this API may change without prior notice.
> + *
> + * Verify the IPv4 UDP/TCP checksum of a packet.
> + *
> + * In case of UDP, the caller must first check if udp_hdr->dgram_cksum is 0
> + * (i.e. no checksum).
> + *
> + * @param m
> + *   The pointer to the mbuf.
> + * @param ipv4_hdr
> + *   The pointer to the contiguous IPv4 header.
> + * @param l4_off
> + *   The offset in bytes to start L4 checksum.
> + * @return
> + *   Return 0 if the checksum is correct, else -1.
> + */
> +__rte_experimental
> +static inline uint16_t
> +rte_ipv4_udptcp_cksum_mbuf_verify(const struct rte_mbuf *m,
> +				  const struct rte_ipv4_hdr *ipv4_hdr,
> +				  uint16_t l4_off)
> +{
> +	uint16_t cksum = __rte_ipv4_udptcp_cksum_mbuf(m, ipv4_hdr, l4_off);
> +
> +	if (cksum != 0xffff)
> +		return -1;
cksum other than 0xffff, should return error. Is that the intent or I am 
missing something obvious.
> +
> +	return 0;
> +}
> +
>   /**
>    * IPv6 Header
>    */
> @@ -538,6 +629,68 @@ rte_ipv6_udptcp_cksum(const struct rte_ipv6_hdr *ipv6_hdr, const void *l4_hdr)
>   	return cksum;
>   }
>   
> +/**
> + * @internal Calculate the non-complemented IPv6 L4 checksum of a packet
> + */
> +static inline uint16_t
> +__rte_ipv6_udptcp_cksum_mbuf(const struct rte_mbuf *m,
> +			     const struct rte_ipv6_hdr *ipv6_hdr,
> +			     uint16_t l4_off)
> +{
> +	uint16_t raw_cksum;
> +	uint32_t cksum;
> +
> +	if (l4_off > m->pkt_len)
> +		return 0;
> +
> +	if (rte_raw_cksum_mbuf(m, l4_off, m->pkt_len - l4_off, &raw_cksum))
> +		return 0;
> +
> +	cksum = raw_cksum + rte_ipv6_phdr_cksum(ipv6_hdr, 0);
> +
> +	cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
Same, please check if we can opt for __rte_raw_cksum_reduce(cksum)
> +
> +	return (uint16_t)cksum;
> +}
> +
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this API may change without prior notice.
> + *
> + * Process the IPv6 UDP or TCP checksum of a packet.
> + *
> + * The IPv6 header must not be followed by extension headers. The layer 4
> + * checksum must be set to 0 in the L4 header by the caller.
> + *
> + * @param m
> + *   The pointer to the mbuf.
> + * @param ipv6_hdr
> + *   The pointer to the contiguous IPv6 header.
> + * @param l4_off
> + *   The offset in bytes to start L4 checksum.
> + * @return
> + *   The complemented checksum to set in the L4 header.
> + */
> +__rte_experimental
> +static inline uint16_t
> +rte_ipv6_udptcp_cksum_mbuf(const struct rte_mbuf *m,
> +			   const struct rte_ipv6_hdr *ipv6_hdr, uint16_t l4_off)
> +{
> +	uint16_t cksum = __rte_ipv6_udptcp_cksum_mbuf(m, ipv6_hdr, l4_off);
> +
> +	cksum = ~cksum;
> +
> +	/*
> +	 * Per RFC 768: If the computed checksum is zero for UDP,
> +	 * it is transmitted as all ones
> +	 * (the equivalent in one's complement arithmetic).
> +	 */
> +	if (cksum == 0 && ipv6_hdr->proto == IPPROTO_UDP)
> +		cksum = 0xffff;
> +
> +	return cksum;
> +}
> +
>   /**
>    * Validate the IPv6 UDP or TCP checksum.
>    *
> @@ -565,6 +718,39 @@ rte_ipv6_udptcp_cksum_verify(const struct rte_ipv6_hdr *ipv6_hdr,
>   	return 0;
>   }
>   
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this API may change without prior notice.
> + *
> + * Validate the IPv6 UDP or TCP checksum of a packet.
> + *
> + * In case of UDP, the caller must first check if udp_hdr->dgram_cksum is 0:
> + * this is either invalid or means no checksum in some situations. See 8.1
> + * (Upper-Layer Checksums) in RFC 8200.
> + *
> + * @param m
> + *   The pointer to the mbuf.
> + * @param ipv6_hdr
> + *   The pointer to the contiguous IPv6 header.
> + * @param l4_off
> + *   The offset in bytes to start L4 checksum.
> + * @return
> + *   Return 0 if the checksum is correct, else -1.
> + */
> +__rte_experimental
> +static inline int
> +rte_ipv6_udptcp_cksum_mbuf_verify(const struct rte_mbuf *m,
> +				  const struct rte_ipv6_hdr *ipv6_hdr,
> +				  uint16_t l4_off)
> +{
> +	uint16_t cksum = __rte_ipv6_udptcp_cksum_mbuf(m, ipv6_hdr, l4_off);
> +
> +	if (cksum != 0xffff)
> +		return -1;
> +
> +	return 0;
> +}
> +
>   /** IPv6 fragment extension header. */
>   #define	RTE_IPV6_EHDR_MF_SHIFT	0
>   #define	RTE_IPV6_EHDR_MF_MASK	1
> diff --git a/lib/net/version.map b/lib/net/version.map
> index 4f4330d1c4..0f2aacdef8 100644
> --- a/lib/net/version.map
> +++ b/lib/net/version.map
> @@ -12,3 +12,13 @@ DPDK_22 {
>   
>   	local: *;
>   };
> +
> +EXPERIMENTAL {
> +	global:
> +
> +	# added in 22.03
> +	rte_ipv4_udptcp_cksum_mbuf;
> +	rte_ipv4_udptcp_cksum_mbuf_verify;
> +	rte_ipv6_udptcp_cksum_mbuf;
> +	rte_ipv6_udptcp_cksum_mbuf_verify;
> +};
Xiaoyun Li Jan. 4, 2022, 3:18 p.m. UTC | #2
Hi

> -----Original Message-----
> From: Singh, Aman Deep <aman.deep.singh@intel.com>
> Sent: Wednesday, December 15, 2021 11:34
> To: Li, Xiaoyun <xiaoyun.li@intel.com>; Yigit, Ferruh
> <ferruh.yigit@intel.com>; olivier.matz@6wind.com;
> mb@smartsharesystems.com; Ananyev, Konstantin
> <konstantin.ananyev@intel.com>; stephen@networkplumber.org;
> Medvedkin, Vladimir <vladimir.medvedkin@intel.com>
> Cc: dev@dpdk.org
> Subject: Re: [PATCH v4 1/2] net: add functions to calculate UDP/TCP cksum in
> mbuf
> 
> 
> On 12/3/2021 5:08 PM, Xiaoyun Li wrote:
> > Add functions to call rte_raw_cksum_mbuf() to calculate IPv4/6 UDP/TCP
> > checksum in mbuf which can be over multi-segments.
> >
> > Signed-off-by: Xiaoyun Li <xiaoyun.li@intel.com>
> > ---
> >   doc/guides/rel_notes/release_22_03.rst |  10 ++
> >   lib/net/rte_ip.h                       | 186 +++++++++++++++++++++++++
> >   lib/net/version.map                    |  10 ++
> >   3 files changed, 206 insertions(+)
> >
> > diff --git a/doc/guides/rel_notes/release_22_03.rst
> > b/doc/guides/rel_notes/release_22_03.rst
> > index 6d99d1eaa9..7a082c4427 100644
> > --- a/doc/guides/rel_notes/release_22_03.rst
> > +++ b/doc/guides/rel_notes/release_22_03.rst
> > @@ -55,6 +55,13 @@ New Features
> >        Also, make sure to start the actual text at the margin.
> >        =======================================================
> >
> > +* **Added functions to calculate UDP/TCP checksum in mbuf.**
> > +  * Added the following functions to calculate UDP/TCP checksum of
> packets
> > +    which can be over multi-segments:
> > +    - ``rte_ipv4_udptcp_cksum_mbuf()``
> > +    - ``rte_ipv4_udptcp_cksum_mbuf_verify()``
> > +    - ``rte_ipv6_udptcp_cksum_mbuf()``
> > +    - ``rte_ipv6_udptcp_cksum_mbuf_verify()``
> >
> >   Removed Items
> >   -------------
> > @@ -84,6 +91,9 @@ API Changes
> >      Also, make sure to start the actual text at the margin.
> >      =======================================================
> >
> > +* net: added experimental functions ``rte_ipv4_udptcp_cksum_mbuf()``,
> > +  ``rte_ipv4_udptcp_cksum_mbuf_verify()``,
> > +``rte_ipv6_udptcp_cksum_mbuf()``,
> > +  ``rte_ipv6_udptcp_cksum_mbuf_verify()``
> >
> >   ABI Changes
> >   -----------
> > diff --git a/lib/net/rte_ip.h b/lib/net/rte_ip.h index
> > c575250852..534f401d26 100644
> > --- a/lib/net/rte_ip.h
> > +++ b/lib/net/rte_ip.h
> > @@ -400,6 +400,65 @@ rte_ipv4_udptcp_cksum(const struct rte_ipv4_hdr
> *ipv4_hdr, const void *l4_hdr)
> >   	return cksum;
> >   }
> >
> > +/**
> > + * @internal Calculate the non-complemented IPv4 L4 checksum of a
> > +packet  */ static inline uint16_t __rte_ipv4_udptcp_cksum_mbuf(const
> > +struct rte_mbuf *m,
> > +			     const struct rte_ipv4_hdr *ipv4_hdr,
> > +			     uint16_t l4_off)
> > +{
> > +	uint16_t raw_cksum;
> > +	uint32_t cksum;
> > +
> > +	if (l4_off > m->pkt_len)
> > +		return 0;
> > +
> > +	if (rte_raw_cksum_mbuf(m, l4_off, m->pkt_len - l4_off,
> &raw_cksum))
> > +		return 0;
> > +
> > +	cksum = raw_cksum + rte_ipv4_phdr_cksum(ipv4_hdr, 0);
> > +
> > +	cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
> At times, even after above operation "cksum" might stay above 16-bits, ex
> "cksum = 0x1FFFF" to start with.
> Can we consider using "return __rte_raw_cksum_reduce(cksum);"

Will use it in next version. Thanks.

Also, not related to this patch. It means that __rte_ipv4_udptcp_cksum and __rte_ipv6_udptcp_cksum have the same issue, right?
Should anyone fix that?

> > +
> > +	return (uint16_t)cksum;
> > +}
> > +
> > +/**
> > + * @warning
> > + * @b EXPERIMENTAL: this API may change without prior notice.
> > + *
> > + * Compute the IPv4 UDP/TCP checksum of a packet.
> > + *
> > + * @param m
> > + *   The pointer to the mbuf.
> > + * @param ipv4_hdr
> > + *   The pointer to the contiguous IPv4 header.
> > + * @param l4_off
> > + *   The offset in bytes to start L4 checksum.
> > + * @return
> > + *   The complemented checksum to set in the L4 header.
> > + */
> > +__rte_experimental
> > +static inline uint16_t
> > +rte_ipv4_udptcp_cksum_mbuf(const struct rte_mbuf *m,
> > +			   const struct rte_ipv4_hdr *ipv4_hdr, uint16_t l4_off)
> {
> > +	uint16_t cksum = __rte_ipv4_udptcp_cksum_mbuf(m, ipv4_hdr,
> l4_off);
> > +
> > +	cksum = ~cksum;
> > +
> > +	/*
> > +	 * Per RFC 768: If the computed checksum is zero for UDP,
> > +	 * it is transmitted as all ones
> > +	 * (the equivalent in one's complement arithmetic).
> > +	 */
> > +	if (cksum == 0 && ipv4_hdr->next_proto_id == IPPROTO_UDP)
> > +		cksum = 0xffff;
> > +
> > +	return cksum;
> > +}
> > +
> >   /**
> >    * Validate the IPv4 UDP or TCP checksum.
> >    *
> > @@ -426,6 +485,38 @@ rte_ipv4_udptcp_cksum_verify(const struct
> rte_ipv4_hdr *ipv4_hdr,
> >   	return 0;
> >   }
> >
> > +/**
> > + * @warning
> > + * @b EXPERIMENTAL: this API may change without prior notice.
> > + *
> > + * Verify the IPv4 UDP/TCP checksum of a packet.
> > + *
> > + * In case of UDP, the caller must first check if
> > +udp_hdr->dgram_cksum is 0
> > + * (i.e. no checksum).
> > + *
> > + * @param m
> > + *   The pointer to the mbuf.
> > + * @param ipv4_hdr
> > + *   The pointer to the contiguous IPv4 header.
> > + * @param l4_off
> > + *   The offset in bytes to start L4 checksum.
> > + * @return
> > + *   Return 0 if the checksum is correct, else -1.
> > + */
> > +__rte_experimental
> > +static inline uint16_t
> > +rte_ipv4_udptcp_cksum_mbuf_verify(const struct rte_mbuf *m,
> > +				  const struct rte_ipv4_hdr *ipv4_hdr,
> > +				  uint16_t l4_off)
> > +{
> > +	uint16_t cksum = __rte_ipv4_udptcp_cksum_mbuf(m, ipv4_hdr,
> l4_off);
> > +
> > +	if (cksum != 0xffff)
> > +		return -1;
> cksum other than 0xffff, should return error. Is that the intent or I am
> missing something obvious.

This is the intent. This function is to verify if the cksum in the packet is correct.

It's different from calling rte_ipv4/6_udptcp_cksum_mbuf(). When calling rte_ipv4/6_udptcp_cksum_mbuf(), you need to set the cksum in udp/tcp header as 0. Then calculate the cksum.

But here, user should directly call this function with the original packet. Then if the udp/tcp cksum is correct, after the calculation (please note that, this is calling __rte_ipv4_udptcp_cksum_mbuf(), so the result needs to be ~), it should be 0xffff, namely, ~cksum = 0 which means cksum is correct. You can see rte_ipv4/6_udptcp_cksum_verify() is doing the same.

> > +
> > +	return 0;
> > +}
> > +
> >   /**
> >    * IPv6 Header
> >    */
> > @@ -538,6 +629,68 @@ rte_ipv6_udptcp_cksum(const struct rte_ipv6_hdr
> *ipv6_hdr, const void *l4_hdr)
> >   	return cksum;
> >   }
> >
> > +/**
> > + * @internal Calculate the non-complemented IPv6 L4 checksum of a
> > +packet  */ static inline uint16_t __rte_ipv6_udptcp_cksum_mbuf(const
> > +struct rte_mbuf *m,
> > +			     const struct rte_ipv6_hdr *ipv6_hdr,
> > +			     uint16_t l4_off)
> > +{
> > +	uint16_t raw_cksum;
> > +	uint32_t cksum;
> > +
> > +	if (l4_off > m->pkt_len)
> > +		return 0;
> > +
> > +	if (rte_raw_cksum_mbuf(m, l4_off, m->pkt_len - l4_off,
> &raw_cksum))
> > +		return 0;
> > +
> > +	cksum = raw_cksum + rte_ipv6_phdr_cksum(ipv6_hdr, 0);
> > +
> > +	cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
> Same, please check if we can opt for __rte_raw_cksum_reduce(cksum)
> > +
> > +	return (uint16_t)cksum;
> > +}
> > +
> > +/**
> > + * @warning
> > + * @b EXPERIMENTAL: this API may change without prior notice.
> > + *
> > + * Process the IPv6 UDP or TCP checksum of a packet.
> > + *
> > + * The IPv6 header must not be followed by extension headers. The
> > +layer 4
> > + * checksum must be set to 0 in the L4 header by the caller.
> > + *
> > + * @param m
> > + *   The pointer to the mbuf.
> > + * @param ipv6_hdr
> > + *   The pointer to the contiguous IPv6 header.
> > + * @param l4_off
> > + *   The offset in bytes to start L4 checksum.
> > + * @return
> > + *   The complemented checksum to set in the L4 header.
> > + */
> > +__rte_experimental
> > +static inline uint16_t
> > +rte_ipv6_udptcp_cksum_mbuf(const struct rte_mbuf *m,
> > +			   const struct rte_ipv6_hdr *ipv6_hdr, uint16_t l4_off)
> {
> > +	uint16_t cksum = __rte_ipv6_udptcp_cksum_mbuf(m, ipv6_hdr,
> l4_off);
> > +
> > +	cksum = ~cksum;
> > +
> > +	/*
> > +	 * Per RFC 768: If the computed checksum is zero for UDP,
> > +	 * it is transmitted as all ones
> > +	 * (the equivalent in one's complement arithmetic).
> > +	 */
> > +	if (cksum == 0 && ipv6_hdr->proto == IPPROTO_UDP)
> > +		cksum = 0xffff;
> > +
> > +	return cksum;
> > +}
> > +
> >   /**
> >    * Validate the IPv6 UDP or TCP checksum.
> >    *
> > @@ -565,6 +718,39 @@ rte_ipv6_udptcp_cksum_verify(const struct
> rte_ipv6_hdr *ipv6_hdr,
> >   	return 0;
> >   }
> >
> > +/**
> > + * @warning
> > + * @b EXPERIMENTAL: this API may change without prior notice.
> > + *
> > + * Validate the IPv6 UDP or TCP checksum of a packet.
> > + *
> > + * In case of UDP, the caller must first check if udp_hdr->dgram_cksum is 0:
> > + * this is either invalid or means no checksum in some situations.
> > +See 8.1
> > + * (Upper-Layer Checksums) in RFC 8200.
> > + *
> > + * @param m
> > + *   The pointer to the mbuf.
> > + * @param ipv6_hdr
> > + *   The pointer to the contiguous IPv6 header.
> > + * @param l4_off
> > + *   The offset in bytes to start L4 checksum.
> > + * @return
> > + *   Return 0 if the checksum is correct, else -1.
> > + */
> > +__rte_experimental
> > +static inline int
> > +rte_ipv6_udptcp_cksum_mbuf_verify(const struct rte_mbuf *m,
> > +				  const struct rte_ipv6_hdr *ipv6_hdr,
> > +				  uint16_t l4_off)
> > +{
> > +	uint16_t cksum = __rte_ipv6_udptcp_cksum_mbuf(m, ipv6_hdr,
> l4_off);
> > +
> > +	if (cksum != 0xffff)
> > +		return -1;
> > +
> > +	return 0;
> > +}
> > +
> >   /** IPv6 fragment extension header. */
> >   #define	RTE_IPV6_EHDR_MF_SHIFT	0
> >   #define	RTE_IPV6_EHDR_MF_MASK	1
> > diff --git a/lib/net/version.map b/lib/net/version.map index
> > 4f4330d1c4..0f2aacdef8 100644
> > --- a/lib/net/version.map
> > +++ b/lib/net/version.map
> > @@ -12,3 +12,13 @@ DPDK_22 {
> >
> >   	local: *;
> >   };
> > +
> > +EXPERIMENTAL {
> > +	global:
> > +
> > +	# added in 22.03
> > +	rte_ipv4_udptcp_cksum_mbuf;
> > +	rte_ipv4_udptcp_cksum_mbuf_verify;
> > +	rte_ipv6_udptcp_cksum_mbuf;
> > +	rte_ipv6_udptcp_cksum_mbuf_verify;
> > +};
Xiaoyun Li Jan. 4, 2022, 3:40 p.m. UTC | #3
Hi

> -----Original Message-----
> From: Li, Xiaoyun <xiaoyun.li@intel.com>
> Sent: Tuesday, January 4, 2022 15:19
> To: Singh, Aman Deep <aman.deep.singh@intel.com>; Yigit, Ferruh
> <ferruh.yigit@intel.com>; olivier.matz@6wind.com;
> mb@smartsharesystems.com; Ananyev, Konstantin
> <konstantin.ananyev@intel.com>; stephen@networkplumber.org;
> Medvedkin, Vladimir <vladimir.medvedkin@intel.com>
> Cc: dev@dpdk.org
> Subject: RE: [PATCH v4 1/2] net: add functions to calculate UDP/TCP cksum in
> mbuf
> 
> Hi
> 
> > -----Original Message-----
> > From: Singh, Aman Deep <aman.deep.singh@intel.com>
> > Sent: Wednesday, December 15, 2021 11:34
> > To: Li, Xiaoyun <xiaoyun.li@intel.com>; Yigit, Ferruh
> > <ferruh.yigit@intel.com>; olivier.matz@6wind.com;
> > mb@smartsharesystems.com; Ananyev, Konstantin
> > <konstantin.ananyev@intel.com>; stephen@networkplumber.org;
> Medvedkin,
> > Vladimir <vladimir.medvedkin@intel.com>
> > Cc: dev@dpdk.org
> > Subject: Re: [PATCH v4 1/2] net: add functions to calculate UDP/TCP
> > cksum in mbuf
> >
> >
> > On 12/3/2021 5:08 PM, Xiaoyun Li wrote:
> > > Add functions to call rte_raw_cksum_mbuf() to calculate IPv4/6
> > > UDP/TCP checksum in mbuf which can be over multi-segments.
> > >
> > > Signed-off-by: Xiaoyun Li <xiaoyun.li@intel.com>
> > > ---
> > >   doc/guides/rel_notes/release_22_03.rst |  10 ++
> > >   lib/net/rte_ip.h                       | 186 +++++++++++++++++++++++++
> > >   lib/net/version.map                    |  10 ++
> > >   3 files changed, 206 insertions(+)
> > >
> > > diff --git a/doc/guides/rel_notes/release_22_03.rst
> > > b/doc/guides/rel_notes/release_22_03.rst
> > > index 6d99d1eaa9..7a082c4427 100644
> > > --- a/doc/guides/rel_notes/release_22_03.rst
> > > +++ b/doc/guides/rel_notes/release_22_03.rst
> > > @@ -55,6 +55,13 @@ New Features
> > >        Also, make sure to start the actual text at the margin.
> > >        =======================================================
> > >
> > > +* **Added functions to calculate UDP/TCP checksum in mbuf.**
> > > +  * Added the following functions to calculate UDP/TCP checksum of
> > packets
> > > +    which can be over multi-segments:
> > > +    - ``rte_ipv4_udptcp_cksum_mbuf()``
> > > +    - ``rte_ipv4_udptcp_cksum_mbuf_verify()``
> > > +    - ``rte_ipv6_udptcp_cksum_mbuf()``
> > > +    - ``rte_ipv6_udptcp_cksum_mbuf_verify()``
> > >
> > >   Removed Items
> > >   -------------
> > > @@ -84,6 +91,9 @@ API Changes
> > >      Also, make sure to start the actual text at the margin.
> > >      =======================================================
> > >
> > > +* net: added experimental functions
> > > +``rte_ipv4_udptcp_cksum_mbuf()``,
> > > +  ``rte_ipv4_udptcp_cksum_mbuf_verify()``,
> > > +``rte_ipv6_udptcp_cksum_mbuf()``,
> > > +  ``rte_ipv6_udptcp_cksum_mbuf_verify()``
> > >
> > >   ABI Changes
> > >   -----------
> > > diff --git a/lib/net/rte_ip.h b/lib/net/rte_ip.h index
> > > c575250852..534f401d26 100644
> > > --- a/lib/net/rte_ip.h
> > > +++ b/lib/net/rte_ip.h
> > > @@ -400,6 +400,65 @@ rte_ipv4_udptcp_cksum(const struct
> rte_ipv4_hdr
> > *ipv4_hdr, const void *l4_hdr)
> > >   	return cksum;
> > >   }
> > >
> > > +/**
> > > + * @internal Calculate the non-complemented IPv4 L4 checksum of a
> > > +packet  */ static inline uint16_t
> > > +__rte_ipv4_udptcp_cksum_mbuf(const
> > > +struct rte_mbuf *m,
> > > +			     const struct rte_ipv4_hdr *ipv4_hdr,
> > > +			     uint16_t l4_off)
> > > +{
> > > +	uint16_t raw_cksum;
> > > +	uint32_t cksum;
> > > +
> > > +	if (l4_off > m->pkt_len)
> > > +		return 0;
> > > +
> > > +	if (rte_raw_cksum_mbuf(m, l4_off, m->pkt_len - l4_off,
> > &raw_cksum))
> > > +		return 0;
> > > +
> > > +	cksum = raw_cksum + rte_ipv4_phdr_cksum(ipv4_hdr, 0);
> > > +
> > > +	cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
> > At times, even after above operation "cksum" might stay above 16-bits,
> > ex "cksum = 0x1FFFF" to start with.
> > Can we consider using "return __rte_raw_cksum_reduce(cksum);"
> 
> Will use it in next version. Thanks.
> 
> Also, not related to this patch. It means that __rte_ipv4_udptcp_cksum and
> __rte_ipv6_udptcp_cksum have the same issue, right?
> Should anyone fix that?

Forgot the intent here.
rte_raw_cksum_mbuf() already calls __rte_raw_cksum_reduce().
So actually, it's a result of uint16_t + uint16_t. So it's impossible of your case. There's no need to call __rte_raw_cksum_reduce().

> 
> > > +
> > > +	return (uint16_t)cksum;
> > > +}
> > > +
> > > +/**
> > > + * @warning
> > > + * @b EXPERIMENTAL: this API may change without prior notice.
> > > + *
> > > + * Compute the IPv4 UDP/TCP checksum of a packet.
> > > + *
> > > + * @param m
> > > + *   The pointer to the mbuf.
> > > + * @param ipv4_hdr
> > > + *   The pointer to the contiguous IPv4 header.
> > > + * @param l4_off
> > > + *   The offset in bytes to start L4 checksum.
> > > + * @return
> > > + *   The complemented checksum to set in the L4 header.
> > > + */
> > > +__rte_experimental
> > > +static inline uint16_t
> > > +rte_ipv4_udptcp_cksum_mbuf(const struct rte_mbuf *m,
> > > +			   const struct rte_ipv4_hdr *ipv4_hdr, uint16_t l4_off)
> > {
> > > +	uint16_t cksum = __rte_ipv4_udptcp_cksum_mbuf(m, ipv4_hdr,
> > l4_off);
> > > +
> > > +	cksum = ~cksum;
> > > +
> > > +	/*
> > > +	 * Per RFC 768: If the computed checksum is zero for UDP,
> > > +	 * it is transmitted as all ones
> > > +	 * (the equivalent in one's complement arithmetic).
> > > +	 */
> > > +	if (cksum == 0 && ipv4_hdr->next_proto_id == IPPROTO_UDP)
> > > +		cksum = 0xffff;
> > > +
> > > +	return cksum;
> > > +}
> > > +
> > >   /**
> > >    * Validate the IPv4 UDP or TCP checksum.
> > >    *
> > > @@ -426,6 +485,38 @@ rte_ipv4_udptcp_cksum_verify(const struct
> > rte_ipv4_hdr *ipv4_hdr,
> > >   	return 0;
> > >   }
> > >
> > > +/**
> > > + * @warning
> > > + * @b EXPERIMENTAL: this API may change without prior notice.
> > > + *
> > > + * Verify the IPv4 UDP/TCP checksum of a packet.
> > > + *
> > > + * In case of UDP, the caller must first check if
> > > +udp_hdr->dgram_cksum is 0
> > > + * (i.e. no checksum).
> > > + *
> > > + * @param m
> > > + *   The pointer to the mbuf.
> > > + * @param ipv4_hdr
> > > + *   The pointer to the contiguous IPv4 header.
> > > + * @param l4_off
> > > + *   The offset in bytes to start L4 checksum.
> > > + * @return
> > > + *   Return 0 if the checksum is correct, else -1.
> > > + */
> > > +__rte_experimental
> > > +static inline uint16_t
> > > +rte_ipv4_udptcp_cksum_mbuf_verify(const struct rte_mbuf *m,
> > > +				  const struct rte_ipv4_hdr *ipv4_hdr,
> > > +				  uint16_t l4_off)
> > > +{
> > > +	uint16_t cksum = __rte_ipv4_udptcp_cksum_mbuf(m, ipv4_hdr,
> > l4_off);
> > > +
> > > +	if (cksum != 0xffff)
> > > +		return -1;
> > cksum other than 0xffff, should return error. Is that the intent or I
> > am missing something obvious.
> 
> This is the intent. This function is to verify if the cksum in the packet is correct.
> 
> It's different from calling rte_ipv4/6_udptcp_cksum_mbuf(). When calling
> rte_ipv4/6_udptcp_cksum_mbuf(), you need to set the cksum in udp/tcp
> header as 0. Then calculate the cksum.
> 
> But here, user should directly call this function with the original packet. Then
> if the udp/tcp cksum is correct, after the calculation (please note that, this is
> calling __rte_ipv4_udptcp_cksum_mbuf(), so the result needs to be ~), it
> should be 0xffff, namely, ~cksum = 0 which means cksum is correct. You can
> see rte_ipv4/6_udptcp_cksum_verify() is doing the same.
> 
> > > +
> > > +	return 0;
> > > +}
> > > +
> > >   /**
> > >    * IPv6 Header
> > >    */
> > > @@ -538,6 +629,68 @@ rte_ipv6_udptcp_cksum(const struct
> rte_ipv6_hdr
> > *ipv6_hdr, const void *l4_hdr)
> > >   	return cksum;
> > >   }
> > >
> > > +/**
> > > + * @internal Calculate the non-complemented IPv6 L4 checksum of a
> > > +packet  */ static inline uint16_t
> > > +__rte_ipv6_udptcp_cksum_mbuf(const
> > > +struct rte_mbuf *m,
> > > +			     const struct rte_ipv6_hdr *ipv6_hdr,
> > > +			     uint16_t l4_off)
> > > +{
> > > +	uint16_t raw_cksum;
> > > +	uint32_t cksum;
> > > +
> > > +	if (l4_off > m->pkt_len)
> > > +		return 0;
> > > +
> > > +	if (rte_raw_cksum_mbuf(m, l4_off, m->pkt_len - l4_off,
> > &raw_cksum))
> > > +		return 0;
> > > +
> > > +	cksum = raw_cksum + rte_ipv6_phdr_cksum(ipv6_hdr, 0);
> > > +
> > > +	cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
> > Same, please check if we can opt for __rte_raw_cksum_reduce(cksum)
> > > +
> > > +	return (uint16_t)cksum;
> > > +}
> > > +
> > > +/**
> > > + * @warning
> > > + * @b EXPERIMENTAL: this API may change without prior notice.
> > > + *
> > > + * Process the IPv6 UDP or TCP checksum of a packet.
> > > + *
> > > + * The IPv6 header must not be followed by extension headers. The
> > > +layer 4
> > > + * checksum must be set to 0 in the L4 header by the caller.
> > > + *
> > > + * @param m
> > > + *   The pointer to the mbuf.
> > > + * @param ipv6_hdr
> > > + *   The pointer to the contiguous IPv6 header.
> > > + * @param l4_off
> > > + *   The offset in bytes to start L4 checksum.
> > > + * @return
> > > + *   The complemented checksum to set in the L4 header.
> > > + */
> > > +__rte_experimental
> > > +static inline uint16_t
> > > +rte_ipv6_udptcp_cksum_mbuf(const struct rte_mbuf *m,
> > > +			   const struct rte_ipv6_hdr *ipv6_hdr, uint16_t l4_off)
> > {
> > > +	uint16_t cksum = __rte_ipv6_udptcp_cksum_mbuf(m, ipv6_hdr,
> > l4_off);
> > > +
> > > +	cksum = ~cksum;
> > > +
> > > +	/*
> > > +	 * Per RFC 768: If the computed checksum is zero for UDP,
> > > +	 * it is transmitted as all ones
> > > +	 * (the equivalent in one's complement arithmetic).
> > > +	 */
> > > +	if (cksum == 0 && ipv6_hdr->proto == IPPROTO_UDP)
> > > +		cksum = 0xffff;
> > > +
> > > +	return cksum;
> > > +}
> > > +
> > >   /**
> > >    * Validate the IPv6 UDP or TCP checksum.
> > >    *
> > > @@ -565,6 +718,39 @@ rte_ipv6_udptcp_cksum_verify(const struct
> > rte_ipv6_hdr *ipv6_hdr,
> > >   	return 0;
> > >   }
> > >
> > > +/**
> > > + * @warning
> > > + * @b EXPERIMENTAL: this API may change without prior notice.
> > > + *
> > > + * Validate the IPv6 UDP or TCP checksum of a packet.
> > > + *
> > > + * In case of UDP, the caller must first check if udp_hdr->dgram_cksum is
> 0:
> > > + * this is either invalid or means no checksum in some situations.
> > > +See 8.1
> > > + * (Upper-Layer Checksums) in RFC 8200.
> > > + *
> > > + * @param m
> > > + *   The pointer to the mbuf.
> > > + * @param ipv6_hdr
> > > + *   The pointer to the contiguous IPv6 header.
> > > + * @param l4_off
> > > + *   The offset in bytes to start L4 checksum.
> > > + * @return
> > > + *   Return 0 if the checksum is correct, else -1.
> > > + */
> > > +__rte_experimental
> > > +static inline int
> > > +rte_ipv6_udptcp_cksum_mbuf_verify(const struct rte_mbuf *m,
> > > +				  const struct rte_ipv6_hdr *ipv6_hdr,
> > > +				  uint16_t l4_off)
> > > +{
> > > +	uint16_t cksum = __rte_ipv6_udptcp_cksum_mbuf(m, ipv6_hdr,
> > l4_off);
> > > +
> > > +	if (cksum != 0xffff)
> > > +		return -1;
> > > +
> > > +	return 0;
> > > +}
> > > +
> > >   /** IPv6 fragment extension header. */
> > >   #define	RTE_IPV6_EHDR_MF_SHIFT	0
> > >   #define	RTE_IPV6_EHDR_MF_MASK	1
> > > diff --git a/lib/net/version.map b/lib/net/version.map index
> > > 4f4330d1c4..0f2aacdef8 100644
> > > --- a/lib/net/version.map
> > > +++ b/lib/net/version.map
> > > @@ -12,3 +12,13 @@ DPDK_22 {
> > >
> > >   	local: *;
> > >   };
> > > +
> > > +EXPERIMENTAL {
> > > +	global:
> > > +
> > > +	# added in 22.03
> > > +	rte_ipv4_udptcp_cksum_mbuf;
> > > +	rte_ipv4_udptcp_cksum_mbuf_verify;
> > > +	rte_ipv6_udptcp_cksum_mbuf;
> > > +	rte_ipv6_udptcp_cksum_mbuf_verify;
> > > +};
Aman Singh Jan. 6, 2022, 12:56 p.m. UTC | #4
On 1/4/2022 9:10 PM, Li, Xiaoyun wrote:
> Hi
>
>> -----Original Message-----
>> From: Li, Xiaoyun<xiaoyun.li@intel.com>
>> Sent: Tuesday, January 4, 2022 15:19
>> To: Singh, Aman Deep<aman.deep.singh@intel.com>; Yigit, Ferruh
>> <ferruh.yigit@intel.com>;olivier.matz@6wind.com;
>> mb@smartsharesystems.com; Ananyev, Konstantin
>> <konstantin.ananyev@intel.com>;stephen@networkplumber.org;
>> Medvedkin, Vladimir<vladimir.medvedkin@intel.com>
>> Cc:dev@dpdk.org
>> Subject: RE: [PATCH v4 1/2] net: add functions to calculate UDP/TCP cksum in
>> mbuf
>>
>> Hi
>>
>>> -----Original Message-----
>>> From: Singh, Aman Deep<aman.deep.singh@intel.com>
>>> Sent: Wednesday, December 15, 2021 11:34
>>> To: Li, Xiaoyun<xiaoyun.li@intel.com>; Yigit, Ferruh
>>> <ferruh.yigit@intel.com>;olivier.matz@6wind.com;
>>> mb@smartsharesystems.com; Ananyev, Konstantin
>>> <konstantin.ananyev@intel.com>;stephen@networkplumber.org;
>> Medvedkin,
>>> Vladimir<vladimir.medvedkin@intel.com>
>>> Cc:dev@dpdk.org
>>> Subject: Re: [PATCH v4 1/2] net: add functions to calculate UDP/TCP
>>> cksum in mbuf
>>>
>>>
>>> On 12/3/2021 5:08 PM, Xiaoyun Li wrote:
>>>> Add functions to call rte_raw_cksum_mbuf() to calculate IPv4/6
>>>> UDP/TCP checksum in mbuf which can be over multi-segments.
>>>>
>>>> Signed-off-by: Xiaoyun Li<xiaoyun.li@intel.com>

Acked-by: Aman Singh <aman.deep.singh@intel.com>

>>>> ---
>>>>    doc/guides/rel_notes/release_22_03.rst |  10 ++
>>>>    lib/net/rte_ip.h                       | 186 +++++++++++++++++++++++++
>>>>    lib/net/version.map                    |  10 ++
>>>>    3 files changed, 206 insertions(+)
>>>>
>>>> diff --git a/doc/guides/rel_notes/release_22_03.rst
>>>> b/doc/guides/rel_notes/release_22_03.rst
>>>> index 6d99d1eaa9..7a082c4427 100644
>>>> --- a/doc/guides/rel_notes/release_22_03.rst
>>>> +++ b/doc/guides/rel_notes/release_22_03.rst
>>>> @@ -55,6 +55,13 @@ New Features
>>>>         Also, make sure to start the actual text at the margin.
>>>>         =======================================================
>>>>
>>>> +* **Added functions to calculate UDP/TCP checksum in mbuf.**
>>>> +  * Added the following functions to calculate UDP/TCP checksum of
>>> packets
>>>> +    which can be over multi-segments:
>>>> +    - ``rte_ipv4_udptcp_cksum_mbuf()``
>>>> +    - ``rte_ipv4_udptcp_cksum_mbuf_verify()``
>>>> +    - ``rte_ipv6_udptcp_cksum_mbuf()``
>>>> +    - ``rte_ipv6_udptcp_cksum_mbuf_verify()``
>>>>
>>>>    Removed Items
>>>>    -------------
>>>> @@ -84,6 +91,9 @@ API Changes
>>>>       Also, make sure to start the actual text at the margin.
>>>>       =======================================================
>>>>
>>>> +* net: added experimental functions
>>>> +``rte_ipv4_udptcp_cksum_mbuf()``,
>>>> +  ``rte_ipv4_udptcp_cksum_mbuf_verify()``,
>>>> +``rte_ipv6_udptcp_cksum_mbuf()``,
>>>> +  ``rte_ipv6_udptcp_cksum_mbuf_verify()``
>>>>
>>>>    ABI Changes
>>>>    -----------
>>>> diff --git a/lib/net/rte_ip.h b/lib/net/rte_ip.h index
>>>> c575250852..534f401d26 100644
>>>> --- a/lib/net/rte_ip.h
>>>> +++ b/lib/net/rte_ip.h
>>>> @@ -400,6 +400,65 @@ rte_ipv4_udptcp_cksum(const struct
>> rte_ipv4_hdr
>>> *ipv4_hdr, const void *l4_hdr)
>>>>    	return cksum;
>>>>    }
>>>>
>>>> +/**
>>>> + * @internal Calculate the non-complemented IPv4 L4 checksum of a
>>>> +packet  */ static inline uint16_t
>>>> +__rte_ipv4_udptcp_cksum_mbuf(const
>>>> +struct rte_mbuf *m,
>>>> +			     const struct rte_ipv4_hdr *ipv4_hdr,
>>>> +			     uint16_t l4_off)
>>>> +{
>>>> +	uint16_t raw_cksum;
>>>> +	uint32_t cksum;
>>>> +
>>>> +	if (l4_off > m->pkt_len)
>>>> +		return 0;
>>>> +
>>>> +	if (rte_raw_cksum_mbuf(m, l4_off, m->pkt_len - l4_off,
>>> &raw_cksum))
>>>> +		return 0;
>>>> +
>>>> +	cksum = raw_cksum + rte_ipv4_phdr_cksum(ipv4_hdr, 0);
>>>> +
>>>> +	cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
>>> At times, even after above operation "cksum" might stay above 16-bits,
>>> ex "cksum = 0x1FFFF" to start with.
>>> Can we consider using "return __rte_raw_cksum_reduce(cksum);"
>> Will use it in next version. Thanks.
>>
>> Also, not related to this patch. It means that __rte_ipv4_udptcp_cksum and
>> __rte_ipv6_udptcp_cksum have the same issue, right?
>> Should anyone fix that?
> Forgot the intent here.
> rte_raw_cksum_mbuf() already calls __rte_raw_cksum_reduce().
> So actually, it's a result of uint16_t + uint16_t. So it's impossible of your case. There's no need to call __rte_raw_cksum_reduce().
Got it, Thanks. With u16 + u16, max 1-bit overflow only possible. So 
effective operation here reduces to-

cksum = ((cksum & 0x10000) >> 16) + (cksum & 0xffff);

>>>> +
>>>> +	return (uint16_t)cksum;
>>>> +}
>>>> +
>>>> +/**
>>>> + * @warning
>>>> + * @b EXPERIMENTAL: this API may change without prior notice.
>>>> + *
>>>> + * Compute the IPv4 UDP/TCP checksum of a packet.
>>>> + *
>>>> + * @param m
>>>> + *   The pointer to the mbuf.
>>>> + * @param ipv4_hdr
>>>> + *   The pointer to the contiguous IPv4 header.
>>>> + * @param l4_off
>>>> + *   The offset in bytes to start L4 checksum.
>>>> + * @return
>>>> + *   The complemented checksum to set in the L4 header.
>>>> + */
>>>> +__rte_experimental
>>>> +static inline uint16_t
>>>> +rte_ipv4_udptcp_cksum_mbuf(const struct rte_mbuf *m,
>>>> +			   const struct rte_ipv4_hdr *ipv4_hdr, uint16_t l4_off)
>>> {
>>>> +	uint16_t cksum = __rte_ipv4_udptcp_cksum_mbuf(m, ipv4_hdr,
>>> l4_off);
>>>> +
>>>> +	cksum = ~cksum;
>>>> +
>>>> +	/*
>>>> +	 * Per RFC 768: If the computed checksum is zero for UDP,
>>>> +	 * it is transmitted as all ones
>>>> +	 * (the equivalent in one's complement arithmetic).
>>>> +	 */
>>>> +	if (cksum == 0 && ipv4_hdr->next_proto_id == IPPROTO_UDP)
>>>> +		cksum = 0xffff;
>>>> +
>>>> +	return cksum;
>>>> +}
>>>> +
>>>>    /**
>>>>     * Validate the IPv4 UDP or TCP checksum.
>>>>     *
>>>> @@ -426,6 +485,38 @@ rte_ipv4_udptcp_cksum_verify(const struct
>>> rte_ipv4_hdr *ipv4_hdr,
>>>>    	return 0;
>>>>    }
>>>>
>>>> +/**
>>>> + * @warning
>>>> + * @b EXPERIMENTAL: this API may change without prior notice.
>>>> + *
>>>> + * Verify the IPv4 UDP/TCP checksum of a packet.
>>>> + *
>>>> + * In case of UDP, the caller must first check if
>>>> +udp_hdr->dgram_cksum is 0
>>>> + * (i.e. no checksum).
>>>> + *
>>>> + * @param m
>>>> + *   The pointer to the mbuf.
>>>> + * @param ipv4_hdr
>>>> + *   The pointer to the contiguous IPv4 header.
>>>> + * @param l4_off
>>>> + *   The offset in bytes to start L4 checksum.
>>>> + * @return
>>>> + *   Return 0 if the checksum is correct, else -1.
>>>> + */
>>>> +__rte_experimental
>>>> +static inline uint16_t
>>>> +rte_ipv4_udptcp_cksum_mbuf_verify(const struct rte_mbuf *m,
>>>> +				  const struct rte_ipv4_hdr *ipv4_hdr,
>>>> +				  uint16_t l4_off)
>>>> +{
>>>> +	uint16_t cksum = __rte_ipv4_udptcp_cksum_mbuf(m, ipv4_hdr,
>>> l4_off);
>>>> +
>>>> +	if (cksum != 0xffff)
>>>> +		return -1;
>>> cksum other than 0xffff, should return error. Is that the intent or I
>>> am missing something obvious.
>> This is the intent. This function is to verify if the cksum in the packet is correct.
>>
>> It's different from calling rte_ipv4/6_udptcp_cksum_mbuf(). When calling
>> rte_ipv4/6_udptcp_cksum_mbuf(), you need to set the cksum in udp/tcp
>> header as 0. Then calculate the cksum.
>>
>> But here, user should directly call this function with the original packet. Then
>> if the udp/tcp cksum is correct, after the calculation (please note that, this is
>> calling __rte_ipv4_udptcp_cksum_mbuf(), so the result needs to be ~), it
>> should be 0xffff, namely, ~cksum = 0 which means cksum is correct. You can
>> see rte_ipv4/6_udptcp_cksum_verify() is doing the same.
>>
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>>    /**
>>>>     * IPv6 Header
>>>>     */
>>>> @@ -538,6 +629,68 @@ rte_ipv6_udptcp_cksum(const struct
>> rte_ipv6_hdr
>>> *ipv6_hdr, const void *l4_hdr)
>>>>    	return cksum;
>>>>    }
>>>>
>>>> +/**
>>>> + * @internal Calculate the non-complemented IPv6 L4 checksum of a
>>>> +packet  */ static inline uint16_t
>>>> +__rte_ipv6_udptcp_cksum_mbuf(const
>>>> +struct rte_mbuf *m,
>>>> +			     const struct rte_ipv6_hdr *ipv6_hdr,
>>>> +			     uint16_t l4_off)
>>>> +{
>>>> +	uint16_t raw_cksum;
>>>> +	uint32_t cksum;
>>>> +
>>>> +	if (l4_off > m->pkt_len)
>>>> +		return 0;
>>>> +
>>>> +	if (rte_raw_cksum_mbuf(m, l4_off, m->pkt_len - l4_off,
>>> &raw_cksum))
>>>> +		return 0;
>>>> +
>>>> +	cksum = raw_cksum + rte_ipv6_phdr_cksum(ipv6_hdr, 0);
>>>> +
>>>> +	cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
>>> Same, please check if we can opt for __rte_raw_cksum_reduce(cksum)
>>>> +
>>>> +	return (uint16_t)cksum;
>>>> +}
>>>> +
>>>> +/**
>>>> + * @warning
>>>> + * @b EXPERIMENTAL: this API may change without prior notice.
>>>> + *
>>>> + * Process the IPv6 UDP or TCP checksum of a packet.
>>>> + *
>>>> + * The IPv6 header must not be followed by extension headers. The
>>>> +layer 4
>>>> + * checksum must be set to 0 in the L4 header by the caller.
>>>> + *
>>>> + * @param m
>>>> + *   The pointer to the mbuf.
>>>> + * @param ipv6_hdr
>>>> + *   The pointer to the contiguous IPv6 header.
>>>> + * @param l4_off
>>>> + *   The offset in bytes to start L4 checksum.
>>>> + * @return
>>>> + *   The complemented checksum to set in the L4 header.
>>>> + */
>>>> +__rte_experimental
>>>> +static inline uint16_t
>>>> +rte_ipv6_udptcp_cksum_mbuf(const struct rte_mbuf *m,
>>>> +			   const struct rte_ipv6_hdr *ipv6_hdr, uint16_t l4_off)
>>> {
>>>> +	uint16_t cksum = __rte_ipv6_udptcp_cksum_mbuf(m, ipv6_hdr,
>>> l4_off);
>>>> +
>>>> +	cksum = ~cksum;
>>>> +
>>>> +	/*
>>>> +	 * Per RFC 768: If the computed checksum is zero for UDP,
>>>> +	 * it is transmitted as all ones
>>>> +	 * (the equivalent in one's complement arithmetic).
>>>> +	 */
>>>> +	if (cksum == 0 && ipv6_hdr->proto == IPPROTO_UDP)
>>>> +		cksum = 0xffff;
>>>> +
>>>> +	return cksum;
>>>> +}
>>>> +
>>>>    /**
>>>>     * Validate the IPv6 UDP or TCP checksum.
>>>>     *
>>>> @@ -565,6 +718,39 @@ rte_ipv6_udptcp_cksum_verify(const struct
>>> rte_ipv6_hdr *ipv6_hdr,
>>>>    	return 0;
>>>>    }
>>>>
>>>> +/**
>>>> + * @warning
>>>> + * @b EXPERIMENTAL: this API may change without prior notice.
>>>> + *
>>>> + * Validate the IPv6 UDP or TCP checksum of a packet.
>>>> + *
>>>> + * In case of UDP, the caller must first check if udp_hdr->dgram_cksum is
>> 0:
>>>> + * this is either invalid or means no checksum in some situations.
>>>> +See 8.1
>>>> + * (Upper-Layer Checksums) in RFC 8200.
>>>> + *
>>>> + * @param m
>>>> + *   The pointer to the mbuf.
>>>> + * @param ipv6_hdr
>>>> + *   The pointer to the contiguous IPv6 header.
>>>> + * @param l4_off
>>>> + *   The offset in bytes to start L4 checksum.
>>>> + * @return
>>>> + *   Return 0 if the checksum is correct, else -1.
>>>> + */
>>>> +__rte_experimental
>>>> +static inline int
>>>> +rte_ipv6_udptcp_cksum_mbuf_verify(const struct rte_mbuf *m,
>>>> +				  const struct rte_ipv6_hdr *ipv6_hdr,
>>>> +				  uint16_t l4_off)
>>>> +{
>>>> +	uint16_t cksum = __rte_ipv6_udptcp_cksum_mbuf(m, ipv6_hdr,
>>> l4_off);
>>>> +
>>>> +	if (cksum != 0xffff)
>>>> +		return -1;
>>>> +
>>>> +	return 0;
>>>> +}
>>>> +
>>>>    /** IPv6 fragment extension header. */
>>>>    #define	RTE_IPV6_EHDR_MF_SHIFT	0
>>>>    #define	RTE_IPV6_EHDR_MF_MASK	1
>>>> diff --git a/lib/net/version.map b/lib/net/version.map index
>>>> 4f4330d1c4..0f2aacdef8 100644
>>>> --- a/lib/net/version.map
>>>> +++ b/lib/net/version.map
>>>> @@ -12,3 +12,13 @@ DPDK_22 {
>>>>
>>>>    	local: *;
>>>>    };
>>>> +
>>>> +EXPERIMENTAL {
>>>> +	global:
>>>> +
>>>> +	# added in 22.03
>>>> +	rte_ipv4_udptcp_cksum_mbuf;
>>>> +	rte_ipv4_udptcp_cksum_mbuf_verify;
>>>> +	rte_ipv6_udptcp_cksum_mbuf;
>>>> +	rte_ipv6_udptcp_cksum_mbuf_verify;
>>>> +};
diff mbox series

Patch

diff --git a/doc/guides/rel_notes/release_22_03.rst b/doc/guides/rel_notes/release_22_03.rst
index 6d99d1eaa9..7a082c4427 100644
--- a/doc/guides/rel_notes/release_22_03.rst
+++ b/doc/guides/rel_notes/release_22_03.rst
@@ -55,6 +55,13 @@  New Features
      Also, make sure to start the actual text at the margin.
      =======================================================
 
+* **Added functions to calculate UDP/TCP checksum in mbuf.**
+  * Added the following functions to calculate UDP/TCP checksum of packets
+    which can be over multi-segments:
+    - ``rte_ipv4_udptcp_cksum_mbuf()``
+    - ``rte_ipv4_udptcp_cksum_mbuf_verify()``
+    - ``rte_ipv6_udptcp_cksum_mbuf()``
+    - ``rte_ipv6_udptcp_cksum_mbuf_verify()``
 
 Removed Items
 -------------
@@ -84,6 +91,9 @@  API Changes
    Also, make sure to start the actual text at the margin.
    =======================================================
 
+* net: added experimental functions ``rte_ipv4_udptcp_cksum_mbuf()``,
+  ``rte_ipv4_udptcp_cksum_mbuf_verify()``, ``rte_ipv6_udptcp_cksum_mbuf()``,
+  ``rte_ipv6_udptcp_cksum_mbuf_verify()``
 
 ABI Changes
 -----------
diff --git a/lib/net/rte_ip.h b/lib/net/rte_ip.h
index c575250852..534f401d26 100644
--- a/lib/net/rte_ip.h
+++ b/lib/net/rte_ip.h
@@ -400,6 +400,65 @@  rte_ipv4_udptcp_cksum(const struct rte_ipv4_hdr *ipv4_hdr, const void *l4_hdr)
 	return cksum;
 }
 
+/**
+ * @internal Calculate the non-complemented IPv4 L4 checksum of a packet
+ */
+static inline uint16_t
+__rte_ipv4_udptcp_cksum_mbuf(const struct rte_mbuf *m,
+			     const struct rte_ipv4_hdr *ipv4_hdr,
+			     uint16_t l4_off)
+{
+	uint16_t raw_cksum;
+	uint32_t cksum;
+
+	if (l4_off > m->pkt_len)
+		return 0;
+
+	if (rte_raw_cksum_mbuf(m, l4_off, m->pkt_len - l4_off, &raw_cksum))
+		return 0;
+
+	cksum = raw_cksum + rte_ipv4_phdr_cksum(ipv4_hdr, 0);
+
+	cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
+
+	return (uint16_t)cksum;
+}
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * Compute the IPv4 UDP/TCP checksum of a packet.
+ *
+ * @param m
+ *   The pointer to the mbuf.
+ * @param ipv4_hdr
+ *   The pointer to the contiguous IPv4 header.
+ * @param l4_off
+ *   The offset in bytes to start L4 checksum.
+ * @return
+ *   The complemented checksum to set in the L4 header.
+ */
+__rte_experimental
+static inline uint16_t
+rte_ipv4_udptcp_cksum_mbuf(const struct rte_mbuf *m,
+			   const struct rte_ipv4_hdr *ipv4_hdr, uint16_t l4_off)
+{
+	uint16_t cksum = __rte_ipv4_udptcp_cksum_mbuf(m, ipv4_hdr, l4_off);
+
+	cksum = ~cksum;
+
+	/*
+	 * Per RFC 768: If the computed checksum is zero for UDP,
+	 * it is transmitted as all ones
+	 * (the equivalent in one's complement arithmetic).
+	 */
+	if (cksum == 0 && ipv4_hdr->next_proto_id == IPPROTO_UDP)
+		cksum = 0xffff;
+
+	return cksum;
+}
+
 /**
  * Validate the IPv4 UDP or TCP checksum.
  *
@@ -426,6 +485,38 @@  rte_ipv4_udptcp_cksum_verify(const struct rte_ipv4_hdr *ipv4_hdr,
 	return 0;
 }
 
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * Verify the IPv4 UDP/TCP checksum of a packet.
+ *
+ * In case of UDP, the caller must first check if udp_hdr->dgram_cksum is 0
+ * (i.e. no checksum).
+ *
+ * @param m
+ *   The pointer to the mbuf.
+ * @param ipv4_hdr
+ *   The pointer to the contiguous IPv4 header.
+ * @param l4_off
+ *   The offset in bytes to start L4 checksum.
+ * @return
+ *   Return 0 if the checksum is correct, else -1.
+ */
+__rte_experimental
+static inline uint16_t
+rte_ipv4_udptcp_cksum_mbuf_verify(const struct rte_mbuf *m,
+				  const struct rte_ipv4_hdr *ipv4_hdr,
+				  uint16_t l4_off)
+{
+	uint16_t cksum = __rte_ipv4_udptcp_cksum_mbuf(m, ipv4_hdr, l4_off);
+
+	if (cksum != 0xffff)
+		return -1;
+
+	return 0;
+}
+
 /**
  * IPv6 Header
  */
@@ -538,6 +629,68 @@  rte_ipv6_udptcp_cksum(const struct rte_ipv6_hdr *ipv6_hdr, const void *l4_hdr)
 	return cksum;
 }
 
+/**
+ * @internal Calculate the non-complemented IPv6 L4 checksum of a packet
+ */
+static inline uint16_t
+__rte_ipv6_udptcp_cksum_mbuf(const struct rte_mbuf *m,
+			     const struct rte_ipv6_hdr *ipv6_hdr,
+			     uint16_t l4_off)
+{
+	uint16_t raw_cksum;
+	uint32_t cksum;
+
+	if (l4_off > m->pkt_len)
+		return 0;
+
+	if (rte_raw_cksum_mbuf(m, l4_off, m->pkt_len - l4_off, &raw_cksum))
+		return 0;
+
+	cksum = raw_cksum + rte_ipv6_phdr_cksum(ipv6_hdr, 0);
+
+	cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
+
+	return (uint16_t)cksum;
+}
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * Process the IPv6 UDP or TCP checksum of a packet.
+ *
+ * The IPv6 header must not be followed by extension headers. The layer 4
+ * checksum must be set to 0 in the L4 header by the caller.
+ *
+ * @param m
+ *   The pointer to the mbuf.
+ * @param ipv6_hdr
+ *   The pointer to the contiguous IPv6 header.
+ * @param l4_off
+ *   The offset in bytes to start L4 checksum.
+ * @return
+ *   The complemented checksum to set in the L4 header.
+ */
+__rte_experimental
+static inline uint16_t
+rte_ipv6_udptcp_cksum_mbuf(const struct rte_mbuf *m,
+			   const struct rte_ipv6_hdr *ipv6_hdr, uint16_t l4_off)
+{
+	uint16_t cksum = __rte_ipv6_udptcp_cksum_mbuf(m, ipv6_hdr, l4_off);
+
+	cksum = ~cksum;
+
+	/*
+	 * Per RFC 768: If the computed checksum is zero for UDP,
+	 * it is transmitted as all ones
+	 * (the equivalent in one's complement arithmetic).
+	 */
+	if (cksum == 0 && ipv6_hdr->proto == IPPROTO_UDP)
+		cksum = 0xffff;
+
+	return cksum;
+}
+
 /**
  * Validate the IPv6 UDP or TCP checksum.
  *
@@ -565,6 +718,39 @@  rte_ipv6_udptcp_cksum_verify(const struct rte_ipv6_hdr *ipv6_hdr,
 	return 0;
 }
 
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * Validate the IPv6 UDP or TCP checksum of a packet.
+ *
+ * In case of UDP, the caller must first check if udp_hdr->dgram_cksum is 0:
+ * this is either invalid or means no checksum in some situations. See 8.1
+ * (Upper-Layer Checksums) in RFC 8200.
+ *
+ * @param m
+ *   The pointer to the mbuf.
+ * @param ipv6_hdr
+ *   The pointer to the contiguous IPv6 header.
+ * @param l4_off
+ *   The offset in bytes to start L4 checksum.
+ * @return
+ *   Return 0 if the checksum is correct, else -1.
+ */
+__rte_experimental
+static inline int
+rte_ipv6_udptcp_cksum_mbuf_verify(const struct rte_mbuf *m,
+				  const struct rte_ipv6_hdr *ipv6_hdr,
+				  uint16_t l4_off)
+{
+	uint16_t cksum = __rte_ipv6_udptcp_cksum_mbuf(m, ipv6_hdr, l4_off);
+
+	if (cksum != 0xffff)
+		return -1;
+
+	return 0;
+}
+
 /** IPv6 fragment extension header. */
 #define	RTE_IPV6_EHDR_MF_SHIFT	0
 #define	RTE_IPV6_EHDR_MF_MASK	1
diff --git a/lib/net/version.map b/lib/net/version.map
index 4f4330d1c4..0f2aacdef8 100644
--- a/lib/net/version.map
+++ b/lib/net/version.map
@@ -12,3 +12,13 @@  DPDK_22 {
 
 	local: *;
 };
+
+EXPERIMENTAL {
+	global:
+
+	# added in 22.03
+	rte_ipv4_udptcp_cksum_mbuf;
+	rte_ipv4_udptcp_cksum_mbuf_verify;
+	rte_ipv6_udptcp_cksum_mbuf;
+	rte_ipv6_udptcp_cksum_mbuf_verify;
+};