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

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 1/24/2022 9:43 AM, Li, Xiaoyun wrote:
> Hi
> 
>> -----Original Message-----
>> From: Yigit, Ferruh <ferruh.yigit@intel.com>
>> Sent: Friday, January 21, 2022 15:17
>> To: Li, Xiaoyun <xiaoyun.li@intel.com>; Singh, Aman Deep
>> <aman.deep.singh@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; Pai G, Sunil <sunil.pai.g@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@intel.com>
>>> Tested-by: Sunil Pai G <sunil.pai.g@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?
> 

Please change the patch title, and it would be good to provide a fix patch,
thanks.

>>
>>
>>> ---
>>>    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)
>> */
>