[PATCH v5 2/2] testpmd: fix l4 sw csum over multi segments

[Li, Xiaoyun]

Hi

> -----Original Message-----
> From: Yigit, Ferruh <ferruh.yigit at intel.com>
> Sent: Friday, January 21, 2022 15:17
> To: Li, Xiaoyun <xiaoyun.li at intel.com>; Singh, Aman Deep
> <aman.deep.singh at intel.com>; olivier.matz at 6wind.com;
> mb at smartsharesystems.com; Ananyev, Konstantin
> <konstantin.ananyev at intel.com>; stephen at networkplumber.org;
> Medvedkin, Vladimir <vladimir.medvedkin at intel.com>
> Cc: dev at dpdk.org; Pai G, Sunil <sunil.pai.g at intel.com>
> Subject: Re: [PATCH v5 2/2] testpmd: fix l4 sw csum over multi segments
> 
> On 1/6/2022 4:03 PM, Xiaoyun Li wrote:
> > In csum forwarding mode, software UDP/TCP csum calculation only takes
> > the first segment into account while using the whole packet length so
> > the calculation will read invalid memory region with multi-segments
> > packets and will get wrong value.
> > This patch fixes this issue.
> >
> > Signed-off-by: Xiaoyun Li <xiaoyun.li at intel.com>
> > Tested-by: Sunil Pai G <sunil.pai.g at intel.com>
> 
> Can you please check following check-git-log.sh warnings:
> 
> ./devtools/check-git-log.sh -2
> Wrong headline label:
>          testpmd: fix l4 sw csum over multi segments Wrong headline case:
>                          "testpmd: fix l4 sw csum over multi segments": l4 --> L4 Wrong
> headline case:
>                          "testpmd: fix l4 sw csum over multi segments": sw --> SW
> Missing 'Fixes' tag:
>          testpmd: fix l4 sw csum over multi segments
> 

Will fix this in next version.
BTW, should I change the patch name to "app/testpmd: enable L4 SW csum over multi segments"? or ignore the fixline complaining?

> 
> 
> > ---
> >   app/test-pmd/csumonly.c | 41 ++++++++++++++++++++++++++-----------
> ----
> >   1 file changed, 26 insertions(+), 15 deletions(-)
> >
> > diff --git a/app/test-pmd/csumonly.c b/app/test-pmd/csumonly.c index
> > 2aeea243b6..0fbe1f1be7 100644
> > --- a/app/test-pmd/csumonly.c
> > +++ b/app/test-pmd/csumonly.c
> > @@ -96,12 +96,13 @@ struct simple_gre_hdr {
> >   } __rte_packed;
> >
> >   static uint16_t
> > -get_udptcp_checksum(void *l3_hdr, void *l4_hdr, uint16_t ethertype)
> > +get_udptcp_checksum(struct rte_mbuf *m, void *l3_hdr, uint16_t l4_off,
> > +		    uint16_t ethertype)
> >   {
> >   	if (ethertype == _htons(RTE_ETHER_TYPE_IPV4))
> > -		return rte_ipv4_udptcp_cksum(l3_hdr, l4_hdr);
> > +		return rte_ipv4_udptcp_cksum_mbuf(m, l3_hdr, l4_off);
> >   	else /* assume ethertype == RTE_ETHER_TYPE_IPV6 */
> > -		return rte_ipv6_udptcp_cksum(l3_hdr, l4_hdr);
> > +		return rte_ipv6_udptcp_cksum_mbuf(m, l3_hdr, l4_off);
> >   }
> >
> >   /* Parse an IPv4 header to fill l3_len, l4_len, and l4_proto */ @@
> > -460,7 +461,7 @@ parse_encap_ip(void *encap_ip, struct
> testpmd_offload_info *info)
> >    * depending on the testpmd command line configuration */
> >   static uint64_t
> >   process_inner_cksums(void *l3_hdr, const struct testpmd_offload_info
> *info,
> > -	uint64_t tx_offloads)
> > +	uint64_t tx_offloads, struct rte_mbuf *m)
> >   {
> >   	struct rte_ipv4_hdr *ipv4_hdr = l3_hdr;
> >   	struct rte_udp_hdr *udp_hdr;
> > @@ -468,6 +469,7 @@ process_inner_cksums(void *l3_hdr, const struct
> testpmd_offload_info *info,
> >   	struct rte_sctp_hdr *sctp_hdr;
> >   	uint64_t ol_flags = 0;
> >   	uint32_t max_pkt_len, tso_segsz = 0;
> > +	uint16_t l4_off;
> >
> >   	/* ensure packet is large enough to require tso */
> >   	if (!info->is_tunnel) {
> > @@ -510,9 +512,15 @@ process_inner_cksums(void *l3_hdr, const struct
> testpmd_offload_info *info,
> >   			if (tx_offloads &
> RTE_ETH_TX_OFFLOAD_UDP_CKSUM) {
> >   				ol_flags |= RTE_MBUF_F_TX_UDP_CKSUM;
> >   			} else {
> > +				if (info->is_tunnel)
> > +					l4_off = info->l2_len +
> > +						 info->outer_l3_len +
> > +						 info->l2_len + info->l3_len;
> > +				else
> > +					l4_off = info->l2_len +	info->l3_len;
> >   				udp_hdr->dgram_cksum = 0;
> >   				udp_hdr->dgram_cksum =
> > -					get_udptcp_checksum(l3_hdr,
> udp_hdr,
> > +					get_udptcp_checksum(m, l3_hdr,
> l4_off,
> >   						info->ethertype);
> >   			}
> >   		}
> > @@ -527,9 +535,14 @@ process_inner_cksums(void *l3_hdr, const struct
> testpmd_offload_info *info,
> >   		else if (tx_offloads & RTE_ETH_TX_OFFLOAD_TCP_CKSUM) {
> >   			ol_flags |= RTE_MBUF_F_TX_TCP_CKSUM;
> >   		} else {
> > +			if (info->is_tunnel)
> > +				l4_off = info->l2_len + info->outer_l3_len +
> > +					 info->l2_len + info->l3_len;
> > +			else
> > +				l4_off = info->l2_len + info->l3_len;
> >   			tcp_hdr->cksum = 0;
> >   			tcp_hdr->cksum =
> > -				get_udptcp_checksum(l3_hdr, tcp_hdr,
> > +				get_udptcp_checksum(m, l3_hdr, l4_off,
> >   					info->ethertype);
> >   		}
> >   #ifdef RTE_LIB_GSO
> > @@ -557,7 +570,7 @@ process_inner_cksums(void *l3_hdr, const struct
> testpmd_offload_info *info,
> >   /* Calculate the checksum of outer header */
> >   static uint64_t
> >   process_outer_cksums(void *outer_l3_hdr, struct testpmd_offload_info
> *info,
> > -	uint64_t tx_offloads, int tso_enabled)
> > +	uint64_t tx_offloads, int tso_enabled, struct rte_mbuf *m)
> >   {
> >   	struct rte_ipv4_hdr *ipv4_hdr = outer_l3_hdr;
> >   	struct rte_ipv6_hdr *ipv6_hdr = outer_l3_hdr; @@ -611,12 +624,9
> @@
> > process_outer_cksums(void *outer_l3_hdr, struct testpmd_offload_info
> *info,
> >   	/* do not recalculate udp cksum if it was 0 */
> >   	if (udp_hdr->dgram_cksum != 0) {
> >   		udp_hdr->dgram_cksum = 0;
> > -		if (info->outer_ethertype == _htons(RTE_ETHER_TYPE_IPV4))
> > -			udp_hdr->dgram_cksum =
> > -				rte_ipv4_udptcp_cksum(ipv4_hdr, udp_hdr);
> > -		else
> > -			udp_hdr->dgram_cksum =
> > -				rte_ipv6_udptcp_cksum(ipv6_hdr, udp_hdr);
> > +		udp_hdr->dgram_cksum = get_udptcp_checksum(m,
> outer_l3_hdr,
> > +					info->l2_len + info->outer_l3_len,
> > +					info->outer_ethertype);
> >   	}
> >
> >   	return ol_flags;
> > @@ -957,7 +967,7 @@ pkt_burst_checksum_forward(struct fwd_stream
> *fs)
> >
> >   		/* process checksums of inner headers first */
> >   		tx_ol_flags |= process_inner_cksums(l3_hdr, &info,
> > -			tx_offloads);
> > +			tx_offloads, m);
> >
> >   		/* Then process outer headers if any. Note that the software
> >   		 * checksum will be wrong if one of the inner checksums is
> @@
> > -965,7 +975,8 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
> >   		if (info.is_tunnel == 1) {
> >   			tx_ol_flags |= process_outer_cksums(outer_l3_hdr,
> &info,
> >   					tx_offloads,
> > -					!!(tx_ol_flags &
> RTE_MBUF_F_TX_TCP_SEG));
> > +					!!(tx_ol_flags &
> RTE_MBUF_F_TX_TCP_SEG),
> > +					m);
> >   		}
> >
> >   		/* step 3: fill the mbuf meta data (flags and header lengths)
> */