Re: [dpdk-dev] [dpdk-dev v2] [PATCH] examples/l2fwd-event: add option to configure port pairs

[Pavan Nikhilesh Bhagavatula <pbhagavatula@marvell.com>]

>> ---
>>  v2 Changes:
>>  - Fix minor formatting error.
>>  - Change uint8_t to bool.
>[...]
>> @@ -99,6 +103,69 @@ l2fwd_event_parse_eventq_sched(const char
>*optarg,
>>  		rsrc->sched_type = RTE_SCHED_TYPE_PARALLEL;
>>  }
>>
>> +static int
>> +l2fwd_parse_port_pair_config(const char *q_arg, struct
>l2fwd_resources *rsrc)
>> +{
>> +	enum fieldnames {
>> +		FLD_PORT1 = 0,
>> +		FLD_PORT2,
>> +		_NUM_FLD
>> +	};
>> +	const char *p, *p0 = q_arg;
>> +	uint16_t int_fld[_NUM_FLD];
>> +	char *str_fld[_NUM_FLD];
>> +	uint16_t port_pair = 0;
>> +	unsigned int size;
>> +	char s[256];
>> +	char *end;
>> +	int i;
>> +
>> +	while ((p = strchr(p0, '(')) != NULL) {
>> +		++p;
>> +		p0 = strchr(p, ')');
>> +		if (p0 == NULL)
>> +			return -1;
>> +
>> +		size = p0 - p;
>> +		if (size >= sizeof(s))
>> +			return -1;
>> +
>> +		snprintf(s, sizeof(s), "%.*s", size, p);
>
>This is a bit peculiar form of memcpy - you want no more than sizeof(s)
>copied but that you checked above so here simple memcpy should be
>enough.

This is a remnant of l3fwd --config options parsing, I will change it to memcpy in 
next version.

>
>> +		if (rte_strsplit(s, sizeof(s), str_fld,
>> +					_NUM_FLD, ',') != _NUM_FLD)
>> +			return -1;
>> +
>> +		for (i = 0; i < _NUM_FLD; i++) {
>> +			errno = 0;
>> +			int_fld[i] = strtoul(str_fld[i], &end, 0);
>> +			if (errno != 0 || end == str_fld[i] || int_fld[i] >
>255)
>
>Replace 255 with check on ">= RTE_MAX_ETHPORTS".	

Will fix in next version.

>
>> +				return -1;
>> +		}
>> +
>> +		if (port_pair >= RTE_MAX_ETHPORTS / 2) {
>> +			printf("exceeded max number of port pair
>params: Current %d Max = %d\n",
>> +			       port_pair, RTE_MAX_ETHPORTS / 2);
>> +			return -1;
>> +		}
>> +
>> +		if ((rsrc->dst_ports[int_fld[FLD_PORT1]] !=
>UINT32_MAX) ||
>> +			(rsrc->dst_ports[int_fld[FLD_PORT2]] !=
>UINT32_MAX)) {
>> +			printf("Duplicate port pair (%d,%d) config\n",
>> +					int_fld[FLD_PORT1],
>int_fld[FLD_PORT2]);
>> +			return -1;
>> +		}
>> +
>> +		rsrc->dst_ports[int_fld[FLD_PORT1]] =
>int_fld[FLD_PORT2];
>> +		rsrc->dst_ports[int_fld[FLD_PORT2]] =
>int_fld[FLD_PORT1];
>> +
>> +		port_pair++;
>> +	}
>> +
>> +	rsrc->port_pairs = true;
>> +
>> +	return 0;
>> +}
>> +
>[...]
>> @@ -209,6 +293,51 @@ l2fwd_event_parse_args(int argc, char
>**argv,
>>  	return ret;
>>  }
>>
>> +/*
>> + * Check port pair config with enabled port mask,
>> + * and for valid port pair combinations.
>> + */
>> +static int
>> +check_port_pair_config(struct l2fwd_resources *rsrc)
>> +{
>> +	uint32_t port_pair_mask = 0;
>> +	uint32_t portid;
>> +	uint16_t index;
>> +
>> +	for (index = 0; index < rte_eth_dev_count_avail(); index++) {
>> +		if ((rsrc->enabled_port_mask & (1 << index)) == 0)
>> +			continue;
>> +
>> +		portid = rsrc->dst_ports[index];
>> +		if (portid == UINT32_MAX) {
>> +			printf("port %u is enabled in but no valid port
>pair\n",
>> +			       index);
>> +			return -1;
>> +		}
>> +
>> +		if (!rte_eth_dev_is_valid_port(index)) {
>> +			printf("port %u is not valid\n", index);
>> +			return -1;
>> +		}
>> +
>> +		if (!rte_eth_dev_is_valid_port(portid)) {
>> +			printf("port %u is not valid\n", portid);
>> +			return -1;
>> +		}
>> +
>> +		if (port_pair_mask & (1 << portid) &&
>> +				rsrc->dst_ports[portid] != index) {
>> +			printf("port %u is used in other port pairs\n",
>portid);
>> +			return -1;
>> +		}
>> +
>> +		port_pair_mask |= (1 << portid);
>> +		port_pair_mask |= (1 << index);
>> +	}
>
>In the above loop you are doing checks twice.  Suppose you have pair
>(2,3) and you go by index from 0 (like you do) and reach point i=2.
>Then you check i=2 and p=3, then on next iteration you do the same
>checks (this time i=3,p=2).  I guess simple fix would be to skip loop
>iteration both on not enabled (like you do) and on check if the port was
>already checked (test bit in port_pair_mask).

Ack, will fix in v3.

>
>With regards
>Andrzej Ostruszka

Thanks,
Pavan.