Re: [tcpdump] About smiInit() parameter

[Guy Harris via tcpdump-workers <tcpdump-workers () lists tcpdump org>]

> --- Begin Message ---
>
>
> From: Guy Harris <gharris () sonic net>
>
> Date: Mon, 30 Mar 2020 10:55:26 -0700
>
>
>
> > On Mar 30, 2020, at 10:24 AM, Francois-Xavier Le Bail <devel.fx.lebail () orange fr> wrote:
> >
> > Hi Guy,
> >
> > We have:
> > $ git grep -n '"tcpdump"'
> > netdissect.c:72:        smiInit("tcpdump");
> >
> > netdissect.c is a part of libnetdissect.
> >
> > Should we use
> > smiInit("libnetdissect");
> > or something else to separate the lib and the tool ?
>
> The man page at
>
>         https://www.ibr.cs.tu-bs.de/projects/libsmi/smi_config.html
>
> says:
>
>         int smiInit(const char *tag);
>
>                 ...
>
>         The smiInit() function should be the first SMI function called in an application.  It initializes its internal 
> structures. If tag is not NULL, the global configuration file and (on UNIX systems) a user configuration file are read 
> implicitly, if existent.  All global statements and those statements with  a tag (a ``tag: '' prefix) that matches the 
> tag argument are executed.  (see also CONFIGURATION FILES below).  
>
> I don't know if anybody's actually *using* that particular libsmi feature, but smiInit has been called with "tcpdump" 
> as an argument since at least tcpdump 0.7.  For what it's worth, the configuration file example they give in the man 
> page *does* have a "tcpdump:" statement in it:
>
>         Example configuration:
>
>           #
>           # $HOME/.smirc
>           #
>
>          # add a private directory
>           path :/usr/home/strauss/lib/mibs
>
>          # don’t show any errors by default
>           level 0
>
>          # preload some basic modules
>           load SNMPv2-SMI
>           load SNMPv2-TC
>           load SNMPv2-CONF
>
>          # want to make smilint shout
>           smilint: level 8
>
>          # but please don’t claim about
>           # any names longer than 32 chars
>           smilint: hide namelength-32
>
>          tcpdump: load DISMAN-SCRIPT-MIB
>
>          smiquery: load IF-MIB
>           smiquery: load DISMAN-SCRIPT-MIB
>
> so there might be some who have "tcpdump:" statements in libsmi configuration files.
>
> So either
>
>         1) we should consider leaving "tcpdump" there
>
> or
>
>         2) we should make the tag an argument to nd_init and pass it "tcpdump" from tcpdump
>
> although the latter means that any new program using libnetdissect might dissect SNMP packets differently from tcpdump, 
> whether that's a bug or a feature.
>
> --- End Message ---
_______________________________________________
tcpdump-workers mailing list
tcpdump-workers () lists tcpdump org
https://lists.sandelman.ca/mailman/listinfo/tcpdump-workers