[dpdk-dev] [PATCH v4 19/29] node: add generic ipv4 lookup node

Andrzej Ostruszka amo at semihalf.com
Fri Apr 10 01:07:34 CEST 2020


On 4/5/20 10:56 AM, jerinj at marvell.com wrote:
> From: Pavan Nikhilesh <pbhagavatula at marvell.com>
> 
> Add IPv4 lookup process function for ip4_lookup node.
> This node performs LPM lookup using simple RTE_LPM API on every packet
> received and forwards it to a next node that is identified by lookup
> result.
> 
> Signed-off-by: Pavan Nikhilesh <pbhagavatula at marvell.com>
> Signed-off-by: Nithin Dabilpuram <ndabilpuram at marvell.com>
[...]
> +static uint16_t
> +ip4_lookup_node_process(struct rte_graph *graph, struct rte_node *node,
> +			void **objs, uint16_t nb_objs)
> +{
> +	struct rte_ipv4_hdr *ipv4_hdr;
> +	void **to_next, **from;
> +	uint16_t last_spec = 0;
> +	struct rte_mbuf *mbuf;
> +	rte_edge_t next_index;
> +	struct rte_lpm *lpm;
> +	uint16_t held = 0;
> +	uint32_t drop_nh;
> +	int i, rc;
> +
> +	/* Speculative next */
> +	next_index = RTE_NODE_IP4_LOOKUP_NEXT_REWRITE;
> +	/* Drop node */
> +	drop_nh = ((uint32_t)RTE_NODE_IP4_LOOKUP_NEXT_PKT_DROP) << 16;
> +
> +	/* Get socket specific LPM from ctx */
> +	lpm = *((struct rte_lpm **)node->ctx);
> +	from = objs;
> +
> +	/* Get stream for the speculated next node */
> +	to_next = rte_node_next_stream_get(graph, node, next_index, nb_objs);
> +	for (i = 0; i < nb_objs; i++) {
> +		uint32_t next_hop;
> +		uint16_t next;
> +
> +		mbuf = (struct rte_mbuf *)objs[i];
> +
> +		/* Extract DIP of mbuf0 */
> +		ipv4_hdr = rte_pktmbuf_mtod_offset(mbuf, struct rte_ipv4_hdr *,
> +				sizeof(struct rte_ether_hdr));
> +		/* Extract cksum, ttl as ipv4 hdr is in cache */
> +		rte_node_mbuf_priv1(mbuf)->cksum = ipv4_hdr->hdr_checksum;
> +		rte_node_mbuf_priv1(mbuf)->ttl = ipv4_hdr->time_to_live;
> +
> +		rc = rte_lpm_lookup(lpm, rte_be_to_cpu_32(ipv4_hdr->dst_addr),
> +				    &next_hop);
> +		next_hop = (rc == 0) ? next_hop : drop_nh;

Maybe simple if here?  I see the same in other patches.

> +
> +		rte_node_mbuf_priv1(mbuf)->nh = (uint16_t)next_hop;
> +		next_hop = next_hop >> 16;
> +		next = (uint16_t)next_hop;
> +
> +		if (unlikely(next_index != next)) {
> +			/* Copy things successfully speculated till now */
> +			rte_memcpy(to_next, from, last_spec * sizeof(from[0]));
> +			from += last_spec;
> +			to_next += last_spec;
> +			held += last_spec;
> +			last_spec = 0;
> +
> +			rte_node_enqueue_x1(graph, node, next, from[0]);
> +			from += 1;
> +		} else {
> +			last_spec += 1;
> +		}
> +	}
> +
> +	/* !!! Home run !!! */
> +	if (likely(last_spec == nb_objs)) {
> +		rte_node_next_stream_move(graph, node, next_index);
> +		return nb_objs;
> +	}
> +	held += last_spec;
> +	rte_memcpy(to_next, from, last_spec * sizeof(from[0]));
> +	rte_node_next_stream_put(graph, node, next_index, held);

OK.  Forget my comments in different mail about difference between
encode/put - I got it now.

> +
> +	return nb_objs;
> +}
> +
[...]

With regards
Andrzej Ostruszka


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