Re: Refactoring src/ausearch-report.c:output_interpreted_node()

[Steve Grubb <sgrubb@redhat.com>]

On Thursday, October 02, 2014 07:52:47 AM Burn Alting wrote:
> On Wed, 2014-10-01 at 17:19 -0400, Steve Grubb wrote:
> > On Thursday, October 02, 2014 07:08:13 AM Burn Alting wrote:
> > > On Wed, 2014-10-01 at 14:54 -0400, Steve Grubb wrote:
> > > > > I am uncertain what effect of accepting this additional format would
> > > > > have when adding rules to the running audit system - i.e.
> > > > > audit_name_to_msg_type() is called by autrace/auditctl when parsing
> > > > > rules (ie the msgtype field name).
> > > > 
> > > > I think ausearch-report.c might be the place that needs updating.
> > > 
> > > So, could we modify output_interpreted_node() to no longer re-parse the
> > > 
> > >    [node=<node>] type=<type> msg=audit(<epochsecs>.<msecs>:<serial>)
> > > 
> > > header and pass both the lnode and llist->e which has this data already
> > > as the code
> > > 
> > >           if (num == -1) {
> > >           
> > >               // see if we are older and wiser now.
> > >               bptr = strchr(str, '[');
> > >               if (bptr && bptr < ptr) {
> > >               
> > >                   char *eptr;
> > >                   bptr++;
> > >                   eptr = strchr(bptr, ']');
> > >                   if (eptr) {
> > >                   
> > >                        *eptr = 0;
> > >                        errno = 0;
> > >                        num = strtoul(bptr, NULL, 10);
> > >                        *eptr = ']';
> > >                        if (errno)
> > >                        
> > >                            num = -1;
> > >                   
> > >                   }
> > >                
> > >                }
> > >          
> > >          }
> > > 
> > > which parses for
> > > 
> > >     type=.*[n].*
> > > 
> > > is no longer needed as we don't have that format any more?
> > 
> > That is a very loose check for UNKNOWN[####]. If you see a performance
> > improvement by refactoring this function, please send a patch. The output
> > needs to be identical to the old way.
> > 
> > Thanks,
> > -Steve
> 
> I can provide a patch to refactor this part of the code, but I want to
> confirm there is no longer a need to parse for
> 
>   type=some_text '[' integer_type ']' some_other_text

While this may have been implied by the code, the fact is that [ ] would only 
be in type fields when its unknown[####].


> given my refactoring will rely upon the parsing already done by
> lib/lookup_table.c:audit_name_to_msg_type(). Remember this routine only
> parses for
> Given
>         type=<type_value>
> then
>         <type_value>
> is parsed for
>         - a known string
>         - a long integer number, n, found in the specific string
>                 "UNKNOWN[n]"
>         - a long integer number, n, found in the specific string
>                 "n"

These 3 formats are all that it can ever be. So, I think you have a correct 
understanding.

-Steve