Re: change ifmedia word from int to uint64_t

[christos%astron.com@localhost (Christos Zoulas)]

In article <aa73b776-930f-2c6d-a7e3-f68f865d9674%execsw.org@localhost>,
Masanobu SAITOH  <msaitoh%execsw.org@localhost> wrote:
> Hi.
>
> I'm now working to extend ifmedia word to be able to support
>more than 10Gbps media.
>
> Patch:
>
>	http://www.netbsd.org/~msaitoh/ifmedia64-20190418-0.dif
>
>I changed ifmedia's word from int to uint64_t. It's almost the
>same as OpenBSD who did 5 years ago.
>
>What do you think about the above diff?
>IMHO, it would be better to change ifmword_t(with uint64_t)
>than uint64_t. For example
>
>(from ifconfig/media.c's diff)
>> @@ -374,7 +374,8 @@ media_status(prop_dictionary_t env, prop
>>  	/* Interface link status is queried through SIOCGIFMEDIA.
>>  	 * Not all interfaces have actual media. */
>>  	if (ifmr.ifm_count != 0) {
>> -		media_list = (int *)malloc(ifmr.ifm_count * sizeof(int));
>> +		media_list = (uint64_t *)malloc(ifmr.ifm_count
>> +		    * sizeof(*media_list));
>>  		if (media_list == NULL)
>>  			err(EXIT_FAILURE, "malloc");
>>  		ifmr.ifm_ulist = media_list;
>
>If we use ifmword_t, it makes easy to change the size in future.
>
>
>This patch has some TODOs:
>
> - COMPAT_NETBSD32? (currently i386 old binary doesn't work on
>   amd64)
> - I would change the hook point. Current location is not good
>   because we have to add "case: OSIOC[GS]IFMEDIA" to all driver
>   which calls ifmedia_ioctl(). (see if_wm.c's patch)

- Casts to malloc are harmful.
- malloc with multiplication should be converted to calloc which
  checks for overflow.

christos