[dpdk-dev] [PATCH v2] examples/l3fwd: fix using packet type blindly

Ananyev, Konstantin konstantin.ananyev at intel.com
Mon Mar 7 19:51:35 CET 2016


Hi Jianfeng,

> 
> +/* Requirements:
> + * 1. IP packets without extension;
> + * 2. L4 payload should be either TCP or UDP.
> + */
> +int
> +em_check_ptype(int portid)
> +{
> +	int i, ret;
> +	int ptype_l3_ipv4_ext = 0;
> +	int ptype_l3_ipv6_ext = 0;
> +	int ptype_l4_tcp = 0;
> +	int ptype_l4_udp = 0;
> +
> +	ret = rte_eth_dev_get_ptype_info(portid,
> +					 RTE_PTYPE_L3_MASK | RTE_PTYPE_L4_MASK,
> +					 NULL, 0);
> +	if (ret <= 0)
> +		return 0;
> +
> +	uint32_t ptypes[ret];
> +
> +	ret = rte_eth_dev_get_ptype_info(portid,
> +					 RTE_PTYPE_L3_MASK | RTE_PTYPE_L4_MASK,
> +					 ptypes, ret);
> +	for (i = 0; i < ret; ++i) {
> +		switch (ptypes[i]) {
> +		case RTE_PTYPE_L3_IPV4_EXT:
> +			ptype_l3_ipv4_ext = 1;
> +			break;
> +		case RTE_PTYPE_L3_IPV6_EXT:
> +			ptype_l3_ipv6_ext = 1;
> +			break;
> +		case RTE_PTYPE_L4_TCP:
> +			ptype_l4_tcp = 1;
> +			break;
> +		case RTE_PTYPE_L4_UDP:
> +			ptype_l4_udp = 1;
> +			break;
> +		}
> +	}
> +
> +	if (ptype_l3_ipv4_ext == 0)
> +		printf("port %d cannot parse RTE_PTYPE_L3_IPV4_EXT\n", portid);
> +	if (ptype_l3_ipv6_ext == 0)
> +		printf("port %d cannot parse RTE_PTYPE_L3_IPV6_EXT\n", portid);
> +	if (!ptype_l3_ipv4_ext || !ptype_l3_ipv6_ext)
> +		return 0;
> +
> +	if (ptype_l4_tcp == 0)
> +		printf("port %d cannot parse RTE_PTYPE_L4_TCP\n", portid);
> +	if (ptype_l4_udp == 0)
> +		printf("port %d cannot parse RTE_PTYPE_L4_UDP\n", portid);
> +	if (ptype_l4_tcp || ptype_l4_udp)
> +		return 1;

Should probably be: if (ptype_l4_tcp && ptype_l4_udp)
?

> +
> +	return 0;
> +}
> +
> +static inline void
> +em_parse_ptype(struct rte_mbuf *m)
> +{
> +	struct ether_hdr *eth_hdr;
> +	uint32_t packet_type = RTE_PTYPE_UNKNOWN;
> +	uint16_t ethertype;
> +	void *l3;
> +	int hdr_len;
> +	struct ipv4_hdr *ipv4_hdr;
> +	struct ipv6_hdr *ipv6_hdr;
> +
> +	eth_hdr = rte_pktmbuf_mtod(m, struct ether_hdr *);
> +	ethertype = rte_be_to_cpu_16(eth_hdr->ether_type);

I think you can avoid bswap here, if use constants in BE format 
for comparison instead:
 
ethertype = eth_hdr->ether_type;
switch (ethertype) {
case (rte_cpu_to_be_16(ETHER_TYPE_IPv4)):
...

Same for lpm.

> 
> @@ -612,6 +622,14 @@ parse_args(int argc, char **argv)
>  					return -1;
>  				}
>  			}
> +
> +			if (!strncmp(lgopts[option_index].name,
> +				     CMD_LINE_OPT_PARSE_PTYPE,
> +				     sizeof(CMD_LINE_OPT_PARSE_PTYPE))) {
> +				printf("soft parse-ptype is enabled\n");
> +				parse_ptype = 1;
> +			}
> +
>  			break;
> 
>  		default:
> @@ -965,6 +983,40 @@ main(int argc, char **argv)
>  			rte_eth_promiscuous_enable(portid);
>  	}
> 
> +	printf("\n");
> +
> +	for (lcore_id = 0; lcore_id < RTE_MAX_LCORE; lcore_id++) {
> +		if (rte_lcore_is_enabled(lcore_id) == 0)
> +			continue;
> +		qconf = &lcore_conf[lcore_id];
> +		for (queue = 0; queue < qconf->n_rx_queue; ++queue) {
> +			portid = qconf->rx_queue_list[queue].port_id;
> +			queueid = qconf->rx_queue_list[queue].queue_id;
> +
> +			ret = l3fwd_lkp.check_ptype(portid);
> +			if (ret) {
> +				printf("Port %d: built-in packet type info\n",
> +				       portid);
> +				continue;
> +			}


I thought that if parse_ptype != 0 we always want to use a SW parsing,
no matter does HW support it or not, no?
So user can measure what is the performance difference between HW and SW versions?
Another thing, that I forgot to ask earlier - with ptype querying in place, would we like to set:
RTE_I40E_INC_VECTOR=y 
by default?

Konstantin


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