[PATCH] Introduce new filtering architecture

[Dmitry V. Levin]

On Mon, Jun 19, 2017 at 08:37:32PM +0700, Nikolay Marchuk wrote:
> On 19.06.2017 11:08, Eugene Syromiatnikov wrote:
> >> +		if (!strncmp(name, str, len)) {
> > Not sure whether strncmp is better than strcmp here, since this function
> > is not called with user-supplied str at all.
> > 
> > Or, do you expect that these will work with user-supplied strings in the
> > future?
> > 
> > BTW, personally, I don't think that this needs to be string-keyed.
> > Something as simple as
> > 
> >     enum filter_type_name {
> >             FILTER_TYPE_syscall,
> >             FILTER_TYPE_fd,
> >     };
> > 
> >     #define FILTER_TYPE(name) \
> >             [FILTER_TYPE_ ## name] = { \
> >                     .parse_filter = parse_ ## name ## _filter, \
> >                     .run_filter = run_ ## name ## _filter, \
> >                     ._free_priv_data = free_ ## name ## _filter, \
> >             }
> > 
> >     static const struct filter_type {
> >             void* (*parse_filter)(const char *, const char *const);
> >             bool (*run_filter)(struct tcb *, void *);
> >             void (*_free_priv_data)(void *);
> >     } filter_types[] = {
> >             FILTER_TYPE(syscall),
> >             FILTER_TYPE(fd),
> >     };
> > 
> >     struct filter *
> >     add_filter_to_array(struct filter **filters, unsigned int *nfilters,
> >                         enum filter_type_name name)
> >     {
> >             *filters = xreallocarray(*filters, ++(*nfilters),
> >                                      sizeof(struct filter));
> >             struct filter *filter = &((*filters)[*nfilters - 1]);
> >             filter->type = filters[name];
> >             return filter;
> >     }
> > 
> >     [...]
> > 
> >     #define create_filter(a, t) actual_create_filter(a, FILTER_TYPE_ ## t)
> > 
> >     [...]
> > 
> >     create_filter(action, fd);
> > 
> > should also suffice.
> I am going to use string-keyed filters and actions for new filtering
> language parsing and enum is not sufficient.

I'm not sure I follow this; how could it be that enum is not sufficient?


-- 
ldv
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