On Fri, Sep 27, 2024 at 03:53:49PM +0200, Laurent Vivier wrote:
> As for tcp_update_check_tcp4()/tcp_update_check_tcp6(),
> change csum_udp4() and csum_udp6() to use an iovec array.
> 
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

> ---
>  checksum.c | 29 ++++++++++++++++++-----------
>  checksum.h |  4 ++--
>  tap.c      | 14 +++++++++++---
>  tap.h      |  2 +-
>  udp.c      | 17 +++++++++++++----
>  5 files changed, 45 insertions(+), 21 deletions(-)
> 
> diff --git a/checksum.c b/checksum.c
> index cf850196cca0..c673993d6f9c 100644
> --- a/checksum.c
> +++ b/checksum.c
> @@ -166,22 +166,24 @@ uint32_t proto_ipv4_header_psum(uint16_t l4len, uint8_t protocol,
>   * @udp4hr:	UDP header, initialised apart from checksum
>   * @saddr:	IPv4 source address
>   * @daddr:	IPv4 destination address
> - * @payload:	UDP packet payload
> - * @dlen:	Length of @payload (not including UDP header)
> + * @iov:	Pointer to the array of IO vectors
> + * @iov_cnt:	Length of the array
> + * @offset:	UDP payload offset in the iovec array
>   */
>  void csum_udp4(struct udphdr *udp4hr,
>  	       struct in_addr saddr, struct in_addr daddr,
> -	       const void *payload, size_t dlen)
> +	       const struct iovec *iov, int iov_cnt, size_t offset)
>  {
>  	/* UDP checksums are optional, so don't bother */
>  	udp4hr->check = 0;
>  
>  	if (UDP4_REAL_CHECKSUMS) {
> -		uint16_t l4len = dlen + sizeof(struct udphdr);
> +		uint16_t l4len = iov_size(iov, iov_cnt) - offset +
> +				 sizeof(struct udphdr);
>  		uint32_t psum = proto_ipv4_header_psum(l4len, IPPROTO_UDP,
>  						       saddr, daddr);
>  		psum = csum_unfolded(udp4hr, sizeof(struct udphdr), psum);
> -		udp4hr->check = csum(payload, dlen, psum);
> +		udp4hr->check = csum_iov(iov, iov_cnt, offset, psum);
>  	}
>  }
>  
> @@ -227,19 +229,24 @@ uint32_t proto_ipv6_header_psum(uint16_t payload_len, uint8_t protocol,
>  /**
>   * csum_udp6() - Calculate and set checksum for a UDP over IPv6 packet
>   * @udp6hr:	UDP header, initialised apart from checksum
> - * @payload:	UDP packet payload
> - * @dlen:	Length of @payload (not including UDP header)
> + * @saddr:	Source address
> + * @daddr:	Destination address
> + * @iov:	Pointer to the array of IO vectors
> + * @iov_cnt:	Length of the array
> + * @offset:	UDP payload offset in the iovec array
>   */
>  void csum_udp6(struct udphdr *udp6hr,
>  	       const struct in6_addr *saddr, const struct in6_addr *daddr,
> -	       const void *payload, size_t dlen)
> +	       const struct iovec *iov, int iov_cnt, size_t offset)
>  {
> -	uint32_t psum = proto_ipv6_header_psum(dlen + sizeof(struct udphdr),
> -					       IPPROTO_UDP, saddr, daddr);
> +	uint16_t l4len = iov_size(iov, iov_cnt) - offset +
> +			 sizeof(struct udphdr);
> +	uint32_t psum = proto_ipv6_header_psum(l4len, IPPROTO_UDP,
> +					       saddr, daddr);
>  	udp6hr->check = 0;
>  
>  	psum = csum_unfolded(udp6hr, sizeof(struct udphdr), psum);
> -	udp6hr->check = csum(payload, dlen, psum);
> +	udp6hr->check = csum_iov(iov, iov_cnt, offset, psum);
>  }
>  
>  /**
> diff --git a/checksum.h b/checksum.h
> index 49f7472dd1b6..31ba322fa98c 100644
> --- a/checksum.h
> +++ b/checksum.h
> @@ -19,14 +19,14 @@ uint32_t proto_ipv4_header_psum(uint16_t l4len, uint8_t protocol,
>  				struct in_addr saddr, struct in_addr daddr);
>  void csum_udp4(struct udphdr *udp4hr,
>  	       struct in_addr saddr, struct in_addr daddr,
> -	       const void *payload, size_t dlen);
> +	       const struct iovec *iov, int iov_cnt, size_t offset);
>  void csum_icmp4(struct icmphdr *icmp4hr, const void *payload, size_t dlen);
>  uint32_t proto_ipv6_header_psum(uint16_t payload_len, uint8_t protocol,
>  				const struct in6_addr *saddr,
>  				const struct in6_addr *daddr);
>  void csum_udp6(struct udphdr *udp6hr,
>  	       const struct in6_addr *saddr, const struct in6_addr *daddr,
> -	       const void *payload, size_t dlen);
> +	       const struct iovec *iov, int iov_cnt, size_t offset);
>  void csum_icmp6(struct icmp6hdr *icmp6hr,
>  		const struct in6_addr *saddr, const struct in6_addr *daddr,
>  		const void *payload, size_t dlen);
> diff --git a/tap.c b/tap.c
> index 41af6a6d0c85..c53a39b79e62 100644
> --- a/tap.c
> +++ b/tap.c
> @@ -172,11 +172,15 @@ void tap_udp4_send(const struct ctx *c, struct in_addr src, in_port_t sport,
>  	struct iphdr *ip4h = tap_push_l2h(c, buf, ETH_P_IP);
>  	struct udphdr *uh = tap_push_ip4h(ip4h, src, dst, l4len, IPPROTO_UDP);
>  	char *data = (char *)(uh + 1);
> +	const struct iovec iov = {
> +		.iov_base = (void *)in,
> +		.iov_len = dlen
> +	};
>  
>  	uh->source = htons(sport);
>  	uh->dest = htons(dport);
>  	uh->len = htons(l4len);
> -	csum_udp4(uh, src, dst, in, dlen);
> +	csum_udp4(uh, src, dst, &iov, 1, 0);
>  	memcpy(data, in, dlen);
>  
>  	tap_send_single(c, buf, dlen + (data - buf));
> @@ -247,7 +251,7 @@ static void *tap_push_ip6h(struct ipv6hdr *ip6h,
>  void tap_udp6_send(const struct ctx *c,
>  		   const struct in6_addr *src, in_port_t sport,
>  		   const struct in6_addr *dst, in_port_t dport,
> -		   uint32_t flow, const void *in, size_t dlen)
> +		   uint32_t flow, void *in, size_t dlen)
>  {
>  	size_t l4len = dlen + sizeof(struct udphdr);
>  	char buf[USHRT_MAX];
> @@ -255,11 +259,15 @@ void tap_udp6_send(const struct ctx *c,
>  	struct udphdr *uh = tap_push_ip6h(ip6h, src, dst,
>  					  l4len, IPPROTO_UDP, flow);
>  	char *data = (char *)(uh + 1);
> +	const struct iovec iov = {
> +		.iov_base = in,
> +		.iov_len = dlen
> +	};
>  
>  	uh->source = htons(sport);
>  	uh->dest = htons(dport);
>  	uh->len = htons(l4len);
> -	csum_udp6(uh, src, dst, in, dlen);
> +	csum_udp6(uh, src, dst, &iov, 1, 0);
>  	memcpy(data, in, dlen);
>  
>  	tap_send_single(c, buf, dlen + (data - buf));
> diff --git a/tap.h b/tap.h
> index ec9e2acec460..85f1e8473711 100644
> --- a/tap.h
> +++ b/tap.h
> @@ -53,7 +53,7 @@ const struct in6_addr *tap_ip6_daddr(const struct ctx *c,
>  void tap_udp6_send(const struct ctx *c,
>  		   const struct in6_addr *src, in_port_t sport,
>  		   const struct in6_addr *dst, in_port_t dport,
> -		   uint32_t flow, const void *in, size_t dlen);
> +		   uint32_t flow, void *in, size_t dlen);
>  void tap_icmp6_send(const struct ctx *c,
>  		    const struct in6_addr *src, const struct in6_addr *dst,
>  		    const void *in, size_t l4len);
> diff --git a/udp.c b/udp.c
> index 7b2831386db8..ac34279db253 100644
> --- a/udp.c
> +++ b/udp.c
> @@ -321,10 +321,15 @@ static size_t udp_update_hdr4(struct iphdr *ip4h, struct udp_payload_t *bp,
>  	bp->uh.source = htons(toside->oport);
>  	bp->uh.dest = htons(toside->eport);
>  	bp->uh.len = htons(l4len);
> -	if (no_udp_csum)
> +	if (no_udp_csum) {
>  		bp->uh.check = 0;
> -	else
> -		csum_udp4(&bp->uh, *src, *dst, bp->data, dlen);
> +	} else {
> +		const struct iovec iov = {
> +			.iov_base = bp->data,
> +			.iov_len = dlen
> +		};
> +		csum_udp4(&bp->uh, *src, *dst, &iov, 1, 0);
> +	}
>  
>  	return l4len;
>  }
> @@ -363,8 +368,12 @@ static size_t udp_update_hdr6(struct ipv6hdr *ip6h, struct udp_payload_t *bp,
>  		 */
>  		bp->uh.check = 0xffff;
>  	} else {
> +		const struct iovec iov = {
> +			.iov_base = bp->data,
> +			.iov_len = dlen
> +		};
>  		csum_udp6(&bp->uh, &toside->oaddr.a6, &toside->eaddr.a6,
> -			  bp->data, dlen);
> +			  &iov, 1, 0);
>  	}
>  
>  	return l4len;

-- 
David Gibson (he or they)	| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you, not the other way
				| around.
http://www.ozlabs.org/~dgibson