rte_fib network order bug

[Robin Jarry]

Hi Vladimir,

I started playing with the new RTE_FIB_F_NETWORK_ORDER flag and I found 
that it does not work at all.

rte_fib is based on rte_rib to perform all slow path lookups and 
modifications. Unfortunately, rte_rib does not handle network order 
addresses. This causes the added routes to be incorrectly masked and 
thus inserted at the wrong place in the dir24 structure.

Here is the config I am using:

static struct rte_fib_conf fib_conf = {
	.type = RTE_FIB_DIR24_8,
	.default_nh = 0,
	.max_routes = 65536,
	.rib_ext_sz = 0,
	.dir24_8 = {
		.nh_sz = RTE_FIB_DIR24_8_8B,
		.num_tbl8 = 1 << 15,
	},
	.flags = RTE_FIB_F_NETWORK_ORDER,
};

And here is a short gdb session demonstrating the issue:

rte_fib_add (fib=0x16ed79740, ip=67305985, depth=24 '\030', next_hop=6438576192) at ../subprojects/dpdk/lib/fib/rte_fib.c:126
126             if ((fib == NULL) || (fib->modify == NULL) ||
(gdb) 
129             return fib->modify(fib, ip, depth, next_hop, RTE_FIB_ADD);
(gdb) p (char*)inet_ntoa(ip)
$9 = 0x7ffff72a471c "1.2.3.4"
(gdb) p depth
$10 = 24 '\030'
(gdb) p fib->flags 
$11 = 1 (
(gdb) s
dir24_8_modify (fib=0x16ed79740, ip=67305985, depth=24 '\030', next_hop=6438576192, op=0)
    at ../subprojects/dpdk/lib/fib/dir24_8.c:452
452             struct rte_rib_node *tmp = NULL;
(gdb) n
455             int ret = 0;
(gdb) 
458             if ((fib == NULL) || (depth > RTE_FIB_MAXDEPTH))
(gdb) 
461             dp = rte_fib_get_dp(fib);
(gdb) 
462             rib = rte_fib_get_rib(fib);
(gdb) 
465             if (next_hop > get_max_nh(dp->nh_sz))
(gdb) 
468             ip &= rte_rib_depth_to_mask(depth);
(gdb) p (char*)inet_ntoa(ip)
$12 = 0x7ffff72a471c "1.2.3.4"
(gdb) p depth
$13 = 24 '\030'
(gdb) n
470             node = rte_rib_lookup_exact(rib, ip, depth);
(gdb) p (char*)inet_ntoa(ip)
$14 = 0x7ffff72a471c "0.2.3.4"
(gdb) p (char*)inet_ntoa(rte_rib_depth_to_mask(depth))
$15 = 0x7ffff72a471c "0.255.255.255"

As you can see, the generated mask is invalid. It should have been 
255.255.255.0.

rte_rib would need to have similar network order support and should 
inherit it from rte_fib.

Let me know if you need more information.