Re: [dpdk-dev] [PATCH v4] examples/ipsec-secgw: fix usage of incorrect port

[Anoob Joseph <anoob.joseph@caviumnetworks.com>]

Hi Akhil, Radu,

I've updated the patch with the suggestions. But I think it will be 
better if we have two separate get_hop_for_offload_pkt() functions(for 
ipv4 & ipv6), since the return type etc is different. It might be 
cleaner that way.

Thanks,

Anoob


On 12/11/2017 09:05 PM, Anoob Joseph wrote:
> When security offload is enabled, the packet should be forwarded on the
> port configured in the SA. Security session will be configured on that
> port only, and sending the packet on other ports could result in
> unencrypted packets being sent out.
>
> This would have performance improvements too, as the per packet LPM
> lookup would be avoided for IPsec packets, in inline mode.
>
> Fixes: ec17993a145a ("examples/ipsec-secgw: support security offload")
>
> Signed-off-by: Anoob Joseph <anoob.joseph@caviumnetworks.com>
> ---
> v4
> * Made get_hop_for_offload_pkt() be aware of the packet type (ipv4/ipv6) and
>    return success/error values accordingly
>
> v3
> * Bug fix (fixed a wrong if condition)
> * Minor changes in documentation
>
> v2:
> * Updated documentation with the change in behavior for outbound inline
>    offloaded packets.
>
>   doc/guides/sample_app_ug/ipsec_secgw.rst |  10 ++-
>   examples/ipsec-secgw/ipsec-secgw.c       | 101 ++++++++++++++++++++++++++-----
>   2 files changed, 96 insertions(+), 15 deletions(-)
>
> diff --git a/doc/guides/sample_app_ug/ipsec_secgw.rst b/doc/guides/sample_app_ug/ipsec_secgw.rst
> index d6cfdbf..ae18acd 100644
> --- a/doc/guides/sample_app_ug/ipsec_secgw.rst
> +++ b/doc/guides/sample_app_ug/ipsec_secgw.rst
> @@ -61,6 +61,12 @@ In case of complete protocol offload, the processing of headers(ESP and outer
>   IP header) is done by the hardware and the application does not need to
>   add/remove them during outbound/inbound processing.
>   
> +For inline offloaded outbound traffic, the application will not do the LPM
> +lookup for routing, as the port on which the packet has to be forwarded will be
> +part of the SA. Security parameters will be configured on that port only, and
> +sending the packet on other ports could result in unencrypted packets being
> +sent out.
> +
>   The Path for IPsec Inbound traffic is:
>   
>   *  Read packets from the port.
> @@ -543,7 +549,9 @@ where each options means:
>    ``<port_id>``
>   
>    * Port/device ID of the ethernet/crypto accelerator for which the SA is
> -   configured. This option is used when *type* is NOT *no-offload*
> +   configured. For *inline-crypto-offload* and *inline-protocol-offload*, this
> +   port will be used for routing. The routing table will not be referred in
> +   this case.
>   
>    * Optional: No, if *type* is not *no-offload*
>   
> diff --git a/examples/ipsec-secgw/ipsec-secgw.c b/examples/ipsec-secgw/ipsec-secgw.c
> index c98454a..c75dd0d 100644
> --- a/examples/ipsec-secgw/ipsec-secgw.c
> +++ b/examples/ipsec-secgw/ipsec-secgw.c
> @@ -585,31 +585,81 @@ process_pkts_outbound_nosp(struct ipsec_ctx *ipsec_ctx,
>   		traffic->ip6.num = nb_pkts_out;
>   }
>   
> +static inline int32_t
> +get_hop_for_offload_pkt(struct rte_mbuf *pkt, int is_ipv6)
> +{
> +	struct ipsec_mbuf_metadata *priv;
> +	struct ipsec_sa *sa;
> +
> +	priv = get_priv(pkt);
> +
> +	sa = priv->sa;
> +	if (unlikely(sa == NULL)) {
> +		RTE_LOG(ERR, IPSEC, "SA not saved in private data\n");
> +		goto fail;
> +	}
> +
> +	if (is_ipv6)
> +		return sa->portid;
> +
> +	/* else */
> +	return (sa->portid | RTE_LPM_LOOKUP_SUCCESS);
> +
> +fail:
> +	if (is_ipv6)
> +		return -1;
> +
> +	/* else */
> +	return 0;
> +}
> +
>   static inline void
>   route4_pkts(struct rt_ctx *rt_ctx, struct rte_mbuf *pkts[], uint8_t nb_pkts)
>   {
>   	uint32_t hop[MAX_PKT_BURST * 2];
>   	uint32_t dst_ip[MAX_PKT_BURST * 2];
> +	int32_t pkt_hop = 0;
>   	uint16_t i, offset;
> +	uint16_t lpm_pkts = 0;
>   
>   	if (nb_pkts == 0)
>   		return;
>   
> +	/* Need to do an LPM lookup for non-offload packets. Offload packets
> +	 * will have port ID in the SA
> +	 */
> +
>   	for (i = 0; i < nb_pkts; i++) {
> -		offset = offsetof(struct ip, ip_dst);
> -		dst_ip[i] = *rte_pktmbuf_mtod_offset(pkts[i],
> -				uint32_t *, offset);
> -		dst_ip[i] = rte_be_to_cpu_32(dst_ip[i]);
> +		if (!(pkts[i]->ol_flags & PKT_TX_SEC_OFFLOAD)) {
> +			/* Security offload not enabled. So an LPM lookup is
> +			 * required to get the hop
> +			 */
> +			offset = offsetof(struct ip, ip_dst);
> +			dst_ip[lpm_pkts] = *rte_pktmbuf_mtod_offset(pkts[i],
> +					uint32_t *, offset);
> +			dst_ip[lpm_pkts] = rte_be_to_cpu_32(dst_ip[lpm_pkts]);
> +			lpm_pkts++;
> +		}
>   	}
>   
> -	rte_lpm_lookup_bulk((struct rte_lpm *)rt_ctx, dst_ip, hop, nb_pkts);
> +	rte_lpm_lookup_bulk((struct rte_lpm *)rt_ctx, dst_ip, hop, lpm_pkts);
> +
> +	lpm_pkts = 0;
>   
>   	for (i = 0; i < nb_pkts; i++) {
> -		if ((hop[i] & RTE_LPM_LOOKUP_SUCCESS) == 0) {
> +		if (pkts[i]->ol_flags & PKT_TX_SEC_OFFLOAD) {
> +			/* Read hop from the SA */
> +			pkt_hop = get_hop_for_offload_pkt(pkts[i], 0);
> +		} else {
> +			/* Need to use hop returned by lookup */
> +			pkt_hop = hop[lpm_pkts++];
> +		}
> +
> +		if ((pkt_hop & RTE_LPM_LOOKUP_SUCCESS) == 0) {
>   			rte_pktmbuf_free(pkts[i]);
>   			continue;
>   		}
> -		send_single_packet(pkts[i], hop[i] & 0xff);
> +		send_single_packet(pkts[i], pkt_hop & 0xff);
>   	}
>   }
>   
> @@ -619,26 +669,49 @@ route6_pkts(struct rt_ctx *rt_ctx, struct rte_mbuf *pkts[], uint8_t nb_pkts)
>   	int32_t hop[MAX_PKT_BURST * 2];
>   	uint8_t dst_ip[MAX_PKT_BURST * 2][16];
>   	uint8_t *ip6_dst;
> +	int32_t pkt_hop = 0;
>   	uint16_t i, offset;
> +	uint16_t lpm_pkts = 0;
>   
>   	if (nb_pkts == 0)
>   		return;
>   
> +	/* Need to do an LPM lookup for non-offload packets. Offload packets
> +	 * will have port ID in the SA
> +	 */
> +
>   	for (i = 0; i < nb_pkts; i++) {
> -		offset = offsetof(struct ip6_hdr, ip6_dst);
> -		ip6_dst = rte_pktmbuf_mtod_offset(pkts[i], uint8_t *, offset);
> -		memcpy(&dst_ip[i][0], ip6_dst, 16);
> +		if (!(pkts[i]->ol_flags & PKT_TX_SEC_OFFLOAD)) {
> +			/* Security offload not enabled. So an LPM lookup is
> +			 * required to get the hop
> +			 */
> +			offset = offsetof(struct ip6_hdr, ip6_dst);
> +			ip6_dst = rte_pktmbuf_mtod_offset(pkts[i], uint8_t *,
> +					offset);
> +			memcpy(&dst_ip[lpm_pkts][0], ip6_dst, 16);
> +			lpm_pkts++;
> +		}
>   	}
>   
> -	rte_lpm6_lookup_bulk_func((struct rte_lpm6 *)rt_ctx, dst_ip,
> -			hop, nb_pkts);
> +	rte_lpm6_lookup_bulk_func((struct rte_lpm6 *)rt_ctx, dst_ip, hop,
> +			lpm_pkts);
> +
> +	lpm_pkts = 0;
>   
>   	for (i = 0; i < nb_pkts; i++) {
> -		if (hop[i] == -1) {
> +		if (pkts[i]->ol_flags & PKT_TX_SEC_OFFLOAD) {
> +			/* Read hop from the SA */
> +			pkt_hop = get_hop_for_offload_pkt(pkts[i], 1);
> +		} else {
> +			/* Need to use hop returned by lookup */
> +			pkt_hop = hop[lpm_pkts++];
> +		}
> +
> +		if (pkt_hop == -1) {
>   			rte_pktmbuf_free(pkts[i]);
>   			continue;
>   		}
> -		send_single_packet(pkts[i], hop[i] & 0xff);
> +		send_single_packet(pkts[i], pkt_hop & 0xff);
>   	}
>   }
>