[PATCH] adding custom options in radv protocol, strict ipv6 regex

Alexander Zubkov green at qrator.net
Fri Jun 30 01:21:13 CEST 2023


Patch for RAdv documentation for a new custom option.

I was also thinking about the new bytestring type. I needed tho change
BYTESTRING -> BYTETEXT to avoid collision. But probably the better
variant would be to name the new type for example "binary", it might
sound better. What do you think? As far as I see, the name
"bytestring" has not been used yet outside of the code.

Also found a small issue with my patches in "conf/confbase.Y" when
compiling with relatively old gcc. It complains on the value
definitions inside the switch statement:

       case T_STRING:
         int len = strlen(val.val.s);
         struct bytestring *bs = cfg_allocz(sizeof(*bs) + len);

I can prepare a new set of patches or you can fix it ad-hoc.

On Thu, Jun 29, 2023 at 1:59 PM Alexander Zubkov <green at qrator.net> wrote:
>
> On Tue, Jun 27, 2023 at 2:13 AM Alexander Zubkov <green at qrator.net> wrote:
> >
> > On Mon, Jun 26, 2023 at 5:54 PM Alexander Zubkov <green at qrator.net> wrote:
> > >
> > > On Mon, Jun 26, 2023 at 5:43 PM Ondrej Zajicek <santiago at crfreenet.org> wrote:
> > > >
> > > > On Mon, Jun 26, 2023 at 03:24:47AM +0200, Alexander Zubkov wrote:
> > > > > On Sat, Jun 24, 2023 at 3:16 PM Ondrej Zajicek <santiago at crfreenet.org> wrote:
> > > > > >
> > > > > > On Sat, Jun 24, 2023 at 02:20:03AM +0200, Alexander Zubkov wrote:
> > > > > > > > Yes, the original idea there was to add bytestring as a data type, make
> > > > > > > > hex() a regular (filter) function instead of special function-like
> > > > > > > > syntax, and add equivalent of 'expr' grammar term for other data types.
> > > > > > > >
> > > > > > >
> > > > > > > I see. I think I can look into preparing a patch for that too.
> > > > > > > But for such variant I would suggest using function names like
> > > > > > > "from_hex/base64" instead of "hex/base64", or something including
> > > > > > > bytestring reference: "bs_hex". Because the simple variants could be
> > > > > > > misleading when used not only in the limited set of scopes.
> > > > > > > they can be thought of converting to hex/base64 representation too. Or they
> > > > > > > could collide with "hex" function to convert from string to int, which
> > > > > > > someone would need to implement in the future.
> > > > > >
> > > > > > Yes, that is true.
> > > > > >
> > > > > > You can try it if you are brave enough to add new f_val type.
> > > > >
> > > > > Take a look at the patch, please. Waiting for the critics and
> > > > > improvement suggestions.
> > > >
> > > > Hi
> > > >
> > > > It looks pretty good. First, could you split it to at least four patches?
> > >
> > > Sure. I'll provide split patches later.
> > >
> > > >
> > > > 1) unrelated changes, like the newline-in-string-constant
> > > > 2) preparatory changes (functions in lib/bytestring.c, change to BYTESTRING lexer)
> > > > 3) adding bytestring type to filter code (including FI_FROM_HEX inst)
> >
> > Added patches up to this point. There are also some fixes and
> > modification. For example, I noted that 'bytestring' symbol for the
> > type name conflicts with lexer's BYTESTRING id. So I had to rename
> > lexer's BYTESTRING to BYTETEXT (like it is done for strings).
> > For the following patches it is better to decide the structure of the
> > new *eval* functions.
> >
> > > > 4) change to parser related to f_eval_val(), bytestring nonterminal and so on.
>
> Final patches to modify current f_eval_int() to generic approach. And
> for nonterminal bytestring.
> Again, waiting for comments/suggestions. Also feel free, of course, to
> fix naming/etc when applying.
> Next, I will be able to move forward with patches to the documentation.
>
> > > >
> > > > Some more comments:
> > > >
> > > > > It was needed to add another function like f_eval_int(), so I decided
> > > > > to do some more generic approach and replaced all occurences of
> > > > > f_eval_int() with it.
> > > >
> > > > That is good approach, although it would be probably better to call this
> > > > function like cf_eval(), associated macro as cf_eval_val, and keep some
> > > > inline functions like cf_eval_int(), cf_eval_bs() and so on.
> > > >
> > > > Or perhaps cf_eval() could return f_val as return value, and have
> > > > shorthand functions like:
> > > >
> > > > static inline cf_eval_int(..) { return cf_eval(.., T_INT).i; }
> >
> > I actually tried first to return the struct instead of modifying it by
> > a reference. But for that we need to have "struct f_val" known in
> > filter/filter.h, which is defined in filter/data.h. But that causes
> > some circular dependencies problem. I didn't dig deep into it, but
> > maybe it is possible to solve the conflict in a clean way.
>
> Looked at it again. It seems safe to include filter/data.h into
> filter/filter.h. I probably had problems when trying to incude it
> somewhere else, until it all finalized into filter.h
>
> >
> > > >
> > > > I will give more comments later.
> > > >
> > > > --
> > > > Elen sila lumenn' omentielvo
> > > >
> > > > Ondrej 'Santiago' Zajicek (email: santiago at crfreenet.org)
> > > > OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net)
> > > > "To err is human -- to blame it on a computer is even more so."
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