[PATCH v3] examples/l3fwd: fix validation for queue id of config tuple

Added validation for queue id of config parameter tuple.

This validation enforces user to enter queue ids of a port
from 0 and in sequence.

This additional validation on queue ids avoids ixgbe crash caused by null
rxq pointer access inside ixgbe_dev_rx_init.

Reason for null rxq is, L3fwd application allocates memory only for queues passed by user.
But rte_eth_dev_start  tries to initialize rx queues in sequence from 0 to nb_rx_queues,
which is not true and coredump while accessing the unallocated queue .

Fixes: af75078fece3 ("first public release")

Signed-off-by: Reshma Pattan <redacted>
---
 v3:
 added Fixes line
 added "\n" at the end of err message.
 
 v2:
 used nested if instead of if and elseif.

 examples/l3fwd/main.c |   11 ++++++++---
 1 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/examples/l3fwd/main.c b/examples/l3fwd/main.c
index 792894f..97a1423 100644
--- a/examples/l3fwd/main.c
+++ b/examples/l3fwd/main.c

@@ -263,9 +263,14 @@ get_port_n_rx_queues(const uint8_t port)
 	uint16_t i;
 
 	for (i = 0; i < nb_lcore_params; ++i) {
-		if (lcore_params[i].port_id == port &&
-			lcore_params[i].queue_id > queue)
-			queue = lcore_params[i].queue_id;
+		if (lcore_params[i].port_id == port) {
+			if (lcore_params[i].queue_id == queue+1)
+				queue = lcore_params[i].queue_id;
+			else
+				rte_exit(EXIT_FAILURE, "queue ids of the port %d must be"
+						" in sequence and must start with 0\n",
+						lcore_params[i].port_id);
+		}
 	}
 	return (uint8_t)(++queue);
 }

-- 
1.7.4.1