On Mon, Oct 26, 2020 at 04:21:48PM -0500, Gustavo A. R. Silva wrote:
> > +/*
> > + * Linux v4.12 and later removed the 64-byte limit on salg_name[]; it's now an
> > + * arbitrary-length field. We had to keep the original struct above for source
> > + * compatibility with existing userspace programs, though. Use the new struct
> > + * below if support for very long algorithm names is needed. To do this,
> > + * allocate 'sizeof(struct sockaddr_alg_new) + strlen(algname) + 1' bytes, and
> > + * copy algname (including the null terminator) into salg_name.
> > + */
> > +struct sockaddr_alg_new {
> > + __u16 salg_family;
> > + __u8 salg_type[14];
> > + __u32 salg_feat;
> > + __u32 salg_mask;
> > + __u8 salg_name[];
> > +};
> > +
>
> How something like this, instead:
>
> struct sockaddr_alg {
> - __u16 salg_family;
> - __u8 salg_type[14];
> - __u32 salg_feat;
> - __u32 salg_mask;
> - __u8 salg_name[64];
> + union {
> + struct {
> + __u16 salg_v1_family;
> + __u8 salg_v1_type[14];
> + __u32 salg_v1_feat;
> + __u32 salg_v1_mask;
> + __u8 salg_name[64];
> + };
> + struct {
> + __u16 salg_family;
> + __u8 salg_type[14];
> + __u32 salg_feat;
> + __u32 salg_mask;
> + __u8 salg_name_new[];
> + };
> + };
> };
>
Something similar to the following approach might work:
https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git/commit/?h=testing/uapi/gntalloc&id=db46c8aba41c436edb0b4ef2941bd7390b0e5d61
--
Gustavo
