Re: [dpdk-dev] [PATCH] lpm6: make IPv6 addresses immutable

["Medvedkin, Vladimir" <vladimir.medvedkin@intel.com>]

Hi Andrze,

Adding const qualifier for bulk lookup leads to compilation problems 
(see http://c-faq.com/ansi/constmismatch.html)
Also I don't think it would be good for usability to make users 
explicitly cast to (const uint8_t **) when passing 'ips' argument. I'd 
suggest leaving lookup_bulk as is.

On 03/03/2020 12:53, Andrzej Ostruszka wrote:
> None of the public functions modify IPv6 address passed so their
> parameters are made const.
>
> Previously only lookup and add were updated to have addresses passed as
> const so I'm adding this fixline.
>
> Fixes: d82927d2f81d ("lpm6: make IPv6 address immutable")
> Cc: stephen@networkplumber.org
>
> Signed-off-by: Andrzej Ostruszka <aostruszka@marvell.com>
> ---
>   lib/librte_lpm/rte_lpm6.c | 14 +++++++-------
>   lib/librte_lpm/rte_lpm6.h | 13 +++++++------
>   2 files changed, 14 insertions(+), 13 deletions(-)
>
> diff --git a/lib/librte_lpm/rte_lpm6.c b/lib/librte_lpm/rte_lpm6.c
> index d515600f1..6089217d6 100644
> --- a/lib/librte_lpm/rte_lpm6.c
> +++ b/lib/librte_lpm/rte_lpm6.c
> @@ -975,8 +975,8 @@ rte_lpm6_lookup(const struct rte_lpm6 *lpm, const uint8_t *ip,
>    */
>   int
>   rte_lpm6_lookup_bulk_func(const struct rte_lpm6 *lpm,
> -		uint8_t ips[][RTE_LPM6_IPV6_ADDR_SIZE],
> -		int32_t *next_hops, unsigned int n)
> +			  const uint8_t ips[][RTE_LPM6_IPV6_ADDR_SIZE],
> +			  int32_t *next_hops, unsigned int n)
>   {
>   	unsigned int i;
>   	const struct rte_lpm6_tbl_entry *tbl;
> @@ -1019,8 +1019,8 @@ rte_lpm6_lookup_bulk_func(const struct rte_lpm6 *lpm,
>    * Look for a rule in the high-level rules table
>    */
>   int
> -rte_lpm6_is_rule_present(struct rte_lpm6 *lpm, uint8_t *ip, uint8_t depth,
> -		uint32_t *next_hop)
> +rte_lpm6_is_rule_present(struct rte_lpm6 *lpm, const uint8_t *ip, uint8_t depth,
> +			 uint32_t *next_hop)
>   {
>   	uint8_t masked_ip[RTE_LPM6_IPV6_ADDR_SIZE];
>   
> @@ -1069,8 +1069,8 @@ rule_delete(struct rte_lpm6 *lpm, uint8_t *ip, uint8_t depth)
>    */
>   int
>   rte_lpm6_delete_bulk_func(struct rte_lpm6 *lpm,
> -		uint8_t ips[][RTE_LPM6_IPV6_ADDR_SIZE], uint8_t *depths,
> -		unsigned n)
> +			  const uint8_t ips[][RTE_LPM6_IPV6_ADDR_SIZE],
> +			  uint8_t *depths, unsigned n)
>   {
>   	uint8_t masked_ip[RTE_LPM6_IPV6_ADDR_SIZE];
>   	unsigned i;
> @@ -1290,7 +1290,7 @@ remove_tbl(struct rte_lpm6 *lpm, struct rte_lpm_tbl8_hdr *tbl_hdr,
>    * Deletes a rule
>    */
>   int
> -rte_lpm6_delete(struct rte_lpm6 *lpm, uint8_t *ip, uint8_t depth)
> +rte_lpm6_delete(struct rte_lpm6 *lpm, const uint8_t *ip, uint8_t depth)
>   {
>   	uint8_t masked_ip[RTE_LPM6_IPV6_ADDR_SIZE];
>   	struct rte_lpm6_rule lsp_rule_obj;
> diff --git a/lib/librte_lpm/rte_lpm6.h b/lib/librte_lpm/rte_lpm6.h
> index 042991f8c..facf09b2b 100644
> --- a/lib/librte_lpm/rte_lpm6.h
> +++ b/lib/librte_lpm/rte_lpm6.h
> @@ -113,8 +113,8 @@ rte_lpm6_add(struct rte_lpm6 *lpm, const uint8_t *ip, uint8_t depth,
>    *   1 if the rule exists, 0 if it does not, a negative value on failure
>    */
>   int
> -rte_lpm6_is_rule_present(struct rte_lpm6 *lpm, uint8_t *ip, uint8_t depth,
> -		uint32_t *next_hop);
> +rte_lpm6_is_rule_present(struct rte_lpm6 *lpm, const uint8_t *ip, uint8_t depth,
> +			 uint32_t *next_hop);
>   
>   /**
>    * Delete a rule from the LPM table.
> @@ -129,7 +129,7 @@ rte_lpm6_is_rule_present(struct rte_lpm6 *lpm, uint8_t *ip, uint8_t depth,
>    *   0 on success, negative value otherwise
>    */
>   int
> -rte_lpm6_delete(struct rte_lpm6 *lpm, uint8_t *ip, uint8_t depth);
> +rte_lpm6_delete(struct rte_lpm6 *lpm, const uint8_t *ip, uint8_t depth);
>   
>   /**
>    * Delete a rule from the LPM table.
> @@ -147,7 +147,8 @@ rte_lpm6_delete(struct rte_lpm6 *lpm, uint8_t *ip, uint8_t depth);
>    */
>   int
>   rte_lpm6_delete_bulk_func(struct rte_lpm6 *lpm,
> -		uint8_t ips[][RTE_LPM6_IPV6_ADDR_SIZE], uint8_t *depths, unsigned n);
> +			  const uint8_t ips[][RTE_LPM6_IPV6_ADDR_SIZE],
> +			  uint8_t *depths, unsigned n);
>   
>   /**
>    * Delete all rules from the LPM table.
> @@ -191,8 +192,8 @@ rte_lpm6_lookup(const struct rte_lpm6 *lpm, const uint8_t *ip, uint32_t *next_ho
>    */
>   int
>   rte_lpm6_lookup_bulk_func(const struct rte_lpm6 *lpm,
> -		uint8_t ips[][RTE_LPM6_IPV6_ADDR_SIZE],
> -		int32_t *next_hops, unsigned int n);
> +			  const uint8_t ips[][RTE_LPM6_IPV6_ADDR_SIZE],
> +			  int32_t *next_hops, unsigned int n);
>   
>   #ifdef __cplusplus
>   }

-- 
Regards,
Vladimir