Re: [PATCH 1/3] libibumad: Support arbitrary number of IB devices

[Ira Weiny <ira.weiny@intel.com>]

On Sun, Aug 11, 2019 at 04:29:20PM +0000, Haim Boozaglo wrote:
> From: Vladimir Koushnir <vladimirk@mellanox.com>
> 
> Added new function returning a list of available InfiniBand device names.
> The returned list is not limited to 32 devices.
> 
> Signed-off-by: Vladimir Koushnir <vladimirk@mellanox.com>
> Signed-off-by: Haim Boozaglo <haimbo@mellanox.com>
> ---

[snip]

> diff --git a/libibumad/umad.c b/libibumad/umad.c
> index 5f8656e..9d0303b 100644
> --- a/libibumad/umad.c
> +++ b/libibumad/umad.c
> @@ -1123,3 +1123,44 @@ void umad_dump(void *umad)
>  	       mad->agent_id, mad->status, mad->timeout_ms);
>  	umad_addr_dump(&mad->addr);
>  }
> +
> +int umad_get_ca_namelist(char **cas)
> +{
> +	struct dirent **namelist;
> +	int n, i, j = 0;
> +
> +	n = scandir(SYS_INFINIBAND, &namelist, NULL, alphasort);
> +
> +	if (n > 0) {
> +		*cas = (char *) calloc(1, n * sizeof(char) * UMAD_CA_NAME_LEN);
> +		for (i = 0; i < n; i++) {
> +			if (*cas && strcmp(namelist[i]->d_name, ".") &&
> +			    strcmp(namelist[i]->d_name, "..")) {
> +				if (is_ib_type(namelist[i]->d_name)) {
> +					strncpy(*cas + j * UMAD_CA_NAME_LEN,
> +						namelist[i]->d_name,
> +						UMAD_CA_NAME_LEN);
> +					j++;
> +				}

This all seems overly complicated to avoid allocating the strings separate from
the pointer array.  Why not just allocate the pointer array and strdup() the
names into the array?  And then make unamd_free_ca_namelist() do some work?

Ira

> +			}
> +			free(namelist[i]);
> +		}
> +		DEBUG("return %d cas", j);
> +	} else {
> +		/* Is this still needed ? */
> +		if ((*cas = calloc(1, UMAD_CA_NAME_LEN * sizeof(char)))) {
> +			strncpy(*cas, def_ca_name, UMAD_CA_NAME_LEN);
> +			DEBUG("return 1 ca");
> +			j = 1;
> +		}
> +	}
> +	if (n >= 0)
> +		free(namelist);
> +
> +	return j;
> +}
> +
> +void umad_free_ca_namelist(char *cas)
> +{
> +	free(cas);
> +}
> diff --git a/libibumad/umad.h b/libibumad/umad.h
> index 3cc551f..70bc213 100644
> --- a/libibumad/umad.h
> +++ b/libibumad/umad.h
> @@ -208,6 +208,8 @@ int umad_register(int portid, int mgmt_class, int mgmt_version,
>  int umad_register_oui(int portid, int mgmt_class, uint8_t rmpp_version,
>  		      uint8_t oui[3], long method_mask[16 / sizeof(long)]);
>  int umad_unregister(int portid, int agentid);
> +int umad_get_ca_namelist(char **cas);
> +void umad_free_ca_namelist(char *cas);
>  
>  enum {
>  	UMAD_USER_RMPP = (1 << 0)
> -- 
> 1.8.3.1
>