Re: [PATCH] rib: fix traversal with /32 route

[Stephen Hemminger <stephen@networkplumber.org>]

On Thu, 14 Apr 2022 13:01:04 -0700
Stephen Hemminger <stephen@networkplumber.org> wrote:

> If a /32 route is entered in the RIB the code to traverse
> will not see that a a end of the tree. This is due to trying
> to do a negative shift which is an undefined in C.
> 
> Fix by checking for max depth as is already done in rib6.
> 
> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
> ---
>  lib/rib/rte_rib.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/lib/rib/rte_rib.c b/lib/rib/rte_rib.c
> index cd9e823068d2..0603980cabd2 100644
> --- a/lib/rib/rte_rib.c
> +++ b/lib/rib/rte_rib.c
> @@ -71,6 +71,8 @@ is_covered(uint32_t ip1, uint32_t ip2, uint8_t depth)
>  static inline struct rte_rib_node *
>  get_nxt_node(struct rte_rib_node *node, uint32_t ip)
>  {
> +	if (node->depth == RIB_MAXDEPTH)
> +		return NULL;
>  	return (ip & (1 << (31 - node->depth))) ? node->right : node->left;
>  }


Fixes: 5a5793a5ffa2 ("rib: add RIB library")