Re: [PATCH RFC net-next 3/5] bonding: add ip6_addr for bond_opt_value

[Hangbin Liu <liuhangbin@gmail.com>]

On Wed, Jan 26, 2022 at 01:35:46PM +0200, Nikolay Aleksandrov wrote:
> > diff --git a/include/net/bond_options.h b/include/net/bond_options.h
> > index dd75c071f67e..a9e68e88ff73 100644
> > --- a/include/net/bond_options.h
> > +++ b/include/net/bond_options.h
> > @@ -79,6 +79,7 @@ struct bond_opt_value {
> >  	char *string;
> >  	u64 value;
> >  	u32 flags;
> > +	struct in6_addr ip6_addr;
> >  };
> >  
> >  struct bonding;
> > @@ -118,17 +119,20 @@ const struct bond_opt_value *bond_opt_get_val(unsigned int option, u64 val);
> >   * When value is ULLONG_MAX then string will be used.
> >   */
> >  static inline void __bond_opt_init(struct bond_opt_value *optval,
> > -				   char *string, u64 value)
> > +				   char *string, u64 value, struct in6_addr *addr)
> >  {
> >  	memset(optval, 0, sizeof(*optval));
> >  	optval->value = ULLONG_MAX;
> > -	if (value == ULLONG_MAX)
> > +	if (string)
> >  		optval->string = string;
> > +	else if (addr)
> > +		optval->ip6_addr = *addr;
> >  	else
> >  		optval->value = value;
> >  }
> > -#define bond_opt_initval(optval, value) __bond_opt_init(optval, NULL, value)
> > -#define bond_opt_initstr(optval, str) __bond_opt_init(optval, str, ULLONG_MAX)
> > +#define bond_opt_initval(optval, value) __bond_opt_init(optval, NULL, value, NULL)
> > +#define bond_opt_initstr(optval, str) __bond_opt_init(optval, str, ULLONG_MAX, NULL)
> > +#define bond_opt_initaddr(optval, addr) __bond_opt_init(optval, NULL, ULLONG_MAX, addr)
> >  
> >  void bond_option_arp_ip_targets_clear(struct bonding *bond);
> >  
> 
> Please don't add arbitrary fields to struct bond_opt_value. As the comment above it states:
> /* This structure is used for storing option values and for passing option
>  * values when changing an option. The logic when used as an arg is as follows:
>  * - if string != NULL -> parse it, if the opt is RAW type then return it, else
>  *   return the parse result
>  * - if string == NULL -> parse value
>  */
> 
> You can use an anonymous union to extend value's size and use the extra room for storage
> only, that should keep most of the current logic intact.

Hi Nikolay,

The current checking for string is (value == ULLONG_MAX). If we use
a union for IPv6 address and value, what about the address like

ffff:ffff:ffff:ffff::/64?

Thanks
Hangbin