[Oisf-devel] geoip keyword syntax

Peter Manev petermanev at gmail.com
Sun Oct 14 09:45:48 UTC 2012


Hi,
I was wondering if the geoip word is IPv4 only? or it supports both IPv6
and v4 ?

thanks

On Sun, Oct 14, 2012 at 1:25 AM, I. Sanchez <sanchezmartin.ji at gmail.com>wrote:

> It is fixed now. It was a silly issue with one "if" (plus a few other
> minor issues in the option string parser).
>
> Now everything seems to be working ok.
>
> The match function looks like this now:
>
> static int DetectGeoipMatch(ThreadVars *t, DetectEngineThreadCtx *det_ctx,
>                              Packet *p, Signature *s, SigMatch *m)
> {
>     DetectGeoipData *geoipdata = (DetectGeoipData *)m->ctx;
>     int match = 0;
>     int matches = 0;
>
>     if (PKT_IS_IPV4(p))
>     {
>         if (geoipdata->flags & GEOIP_MATCH_SRC_FLAG || geoipdata->flags & GEOIP_MATCH_BOTH_FLAG)
>         {
>             /* if there is a flow get SRC IP of the flow, not packet */
>
>             if (p->flowflags & FLOW_PKT_TOCLIENT)
>                 /* the dst (from server to client) is our src */
>                 match = CheckGeoMatchIPv4(geoipdata, GET_IPV4_DST_ADDR_U32(p));
>             else
>                 match = CheckGeoMatchIPv4(geoipdata, GET_IPV4_SRC_ADDR_U32(p));
>             if (match)
>             {
>
>                 if (geoipdata->flags & GEOIP_MATCH_BOTH_FLAG)
>                     matches++;
>                 else
>                     return 1;
>             }
>
>         }
>         if (geoipdata->flags & GEOIP_MATCH_DST_FLAG || geoipdata->flags & GEOIP_MATCH_BOTH_FLAG)
>         {
>             /* if there is a flow get DST IP of the flow, not packet */
>
>             if (p->flowflags & FLOW_PKT_TOCLIENT)
>                 /* the src (from server to client) is our dst */
>                 match = CheckGeoMatchIPv4(geoipdata, GET_IPV4_SRC_ADDR_U32(p));
>             else
>                 match = CheckGeoMatchIPv4(geoipdata, GET_IPV4_DST_ADDR_U32(p));
>             if (match)
>             {
>
>                 if (geoipdata->flags & GEOIP_MATCH_BOTH_FLAG)
>                     matches++;
>                 else
>                     return 1;
>             }
>
>         }
>         /* if matches == 2 is because match-on is "both" */
>         if (matches == 2)
>             return 1;
>     }
>
>     return 0;
> }
>
>
>
> On Sat, Oct 13, 2012 at 9:46 PM, I. Sanchez <sanchezmartin.ji at gmail.com>wrote:
>
>> Ok, I have done an initial implementation (just country geolocation for
>> now). It is available at https://github.com/owlsec/suricata/tree/geoip
>>
>> When checking a packet, I take into account the flow source and
>> destination IPs for the match-on condition, if a flow exists. However in my
>> tests I have seen it is not working well... a geoip:src,US; rule will be
>> triggered as well when talking HTTP to google.com from a non US source
>> IP address.
>>
>> I am not sure about the reason of this behavior, so perhaps somebody
>> could let me know what is wrong here.
>>
>> https://github.com/owlsec/suricata/blob/geoip/src/detect-geoip.c
>>
>> The relevant function is this one:
>>
>> static int DetectGeoipMatch(ThreadVars *t, DetectEngineThreadCtx *det_ctx,
>>
>>                              Packet *p, Signature *s, SigMatch *m)
>>
>> {
>>     DetectGeoipData *geoipdata = (DetectGeoipData *)m->ctx;
>>
>>     int match = 0;
>>     int matches = 0;
>>     uint32_t ip;
>>
>>     if (PKT_IS_IPV4(p))
>>     {
>>         if (geoipdata->flags & GEOIP_MATCH_SRC_FLAG || geoipdata->flags & GEOIP_MATCH_BOTH_FLAG)
>>
>>         {
>>             /* if there is a flow get SRC IP of the flow, not packet */
>>
>>             if (p->flowflags & FLOW_PKT_TOCLIENT)
>>                 ip = GET_IPV4_DST_ADDR_U32(p); /* the dst (from server to client) is our src */
>>             else
>>                 ip = GET_IPV4_SRC_ADDR_U32(p);
>>             match = CheckGeoMatchIPv4(geoipdata, ip);
>>             if (match && geoipdata->flags & GEOIP_MATCH_BOTH_FLAG)
>>
>>                 matches++;
>>             else
>>                 return 1;
>>         }
>>
>>         if (geoipdata->flags & GEOIP_MATCH_DST_FLAG || geoipdata->flags & GEOIP_MATCH_BOTH_FLAG)
>>
>>         {
>>             /* if there is a flow get DST IP of the flow, not packet */
>>
>>             if (p->flowflags & FLOW_PKT_TOCLIENT)
>>                 ip = GET_IPV4_SRC_ADDR_U32(p); /* the src (from server to client) is our dst */
>>             else
>>                 ip = GET_IPV4_DST_ADDR_U32(p);
>>             match = CheckGeoMatchIPv4(geoipdata, ip);
>>             if (match && geoipdata->flags & GEOIP_MATCH_BOTH_FLAG)
>>
>>                 matches++;
>>             else
>>                 return 1;
>>         }
>>
>>         /* if matches == 2 is because match-on is "both" */
>>         if (matches == 2)
>>             return 1;
>>     }
>>
>>     return 0;
>> }
>>
>>
>>
>> On Fri, Oct 12, 2012 at 11:35 AM, I. Sanchez <sanchezmartin.ji at gmail.com>wrote:
>>
>>> Yes, I forgot to mention it. Negation will be supported.
>>>
>>>
>>> On Fri, Oct 12, 2012 at 10:03 AM, Peter Manev <petermanev at gmail.com>wrote:
>>>
>>>> Excellent - thank you.
>>>> comments bellow ...
>>>>
>>>> On Thu, Oct 11, 2012 at 10:07 PM, I. Sanchez <
>>>> sanchezmartin.ji at gmail.com> wrote:
>>>>
>>>>> Good idea, I will implement multiple conditions(countries) in the same
>>>>> rule. Let's use the <match-on><condition>+ syntax where match-on can be
>>>>> src, dst, both or any.
>>>>>
>>>>>
>>>>> alert http any any -> any any (msg:"GEOIP: IP located in
>>>>> US/Germany/Canada/France";* geoip:src,US,DE,CA,FR*; sid:3450002;
>>>>> rev:1;)
>>>>>
>>>>> I can also support geoip:US; by assuming geoip:any,US; , for
>>>>> simplicity.
>>>>>
>>>>
>>>> I agree with the assumption here - i think it is good to assume so.
>>>> I was thinking further on the matter and I am not sure if i am starting
>>>> to sound annoying - but wouldn't it be nice if we can also negate geoip? :
>>>> alert http any any -> any any (msg:"GEOIP: IP destination  *NOT*located in US/Canada";
>>>> * *geoip:*dst,!*US,CA; sid:3450002; rev:1;)
>>>>
>>>>
>>>>
>>>>> Regarding the city support, indeed the MaxMind DBs in their free
>>>>> versions support cities in addition to countries although the accuracy
>>>>> drops from 99.5% (for countries) to 78% in US (for cities), and I guess
>>>>> much less accuracy in other countries.
>>>>>
>>>>> In the commercial DBs, they apparently support regions,
>>>>> organizations... http://www.maxmind.com/en/geolocation_landing
>>>>>
>>>>> For now I will just implement support for countries, but we should
>>>>> take this into account for the keyword syntax. I see some options:
>>>>>
>>>>>    - Autodetect city vs country. I could detect whether the condition
>>>>>    is a known country code, and assume city otherwise. However this will not
>>>>>    work for regions, organizations...
>>>>>    - Allow -for future versions- the check type as an optional param
>>>>>    of the <match-on> condition. ie: geoip:src,city,Madrid;
>>>>>
>>>>>
>>>> this would be awesome in my opinion.
>>>>
>>>>>
>>>>>
>>>>> Regards,
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> On Thu, Oct 11, 2012 at 9:02 PM, Peter Manev <petermanev at gmail.com>wrote:
>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> I think i love that new geoip keyword - thank you for the efforts !
>>>>>>
>>>>>> A couple of suggestions/requests if I may:
>>>>>>
>>>>>> 1.I agree/like the proposal - but I wonder if it would be possible to
>>>>>> include multiples(maybe up to a certain number [32 or something] ) of
>>>>>> countries - like:
>>>>>> alert http any any -> any any (msg:"GEOIP: IP located in
>>>>>> US/Germany/Canada/France";* geoip:src,US,DE,CA,FR*; sid:3450002;
>>>>>> rev:1;)
>>>>>>
>>>>>> 2. As there is - *src, dst, both* - i think it would be nice if
>>>>>> there is also "*any*" -
>>>>>> alert http any any -> any any (msg:"GEOIP: some traffic to/from the
>>>>>> Cayman Islands";* geoip:any,KY*; sid:3450005; rev:1;)
>>>>>> any - meaning either source or destination.
>>>>>>
>>>>>> thanks a bunch!
>>>>>>
>>>>>>
>>>>>> On Thu, Oct 11, 2012 at 6:42 PM, Victor Julien <victor at inliniac.net>wrote:
>>>>>>
>>>>>>> On 10/11/2012 06:16 PM, I. Sanchez wrote:
>>>>>>> > Hi,
>>>>>>> >
>>>>>>> > I am implementing support for IP address country geolocation in
>>>>>>> > Suricata, and I wanted to ask your opinion about the syntax to be
>>>>>>> used
>>>>>>> > for the geoip keyword options.
>>>>>>> >
>>>>>>> > https://redmine.openinfosecfoundation.org/issues/559
>>>>>>> >
>>>>>>> > The keyword options would be:
>>>>>>> >
>>>>>>> >   * Country code. ie: US
>>>>>>> >   * Match condition: match on source IP, match on destination IP,
>>>>>>> or
>>>>>>> >     match on both.
>>>>>>> >
>>>>>>> > What do you think would be the best syntax for this?
>>>>>>> >
>>>>>>> > Some possibilities:
>>>>>>> >
>>>>>>> >   * geoip:<src|dst|both>,<countrycode>;
>>>>>>> >       o alert http any any -> any any (msg:"GEOIP: IP located in
>>>>>>> >         US";*geoip:src,US*;sid:3450002;rev:1;)
>>>>>>> >   * geoip:<countrycode>,<src|dst|both>;
>>>>>>> >       o alert http any any -> any any (msg:"GEOIP: IP located in
>>>>>>> >         US";*geoip:US,src*;sid:3450002;rev:1;)
>>>>>>>
>>>>>>> Thanks for picking this up!
>>>>>>>
>>>>>>> Doesn't the geoip also allow for other types of data, such as city?
>>>>>>> I'm
>>>>>>> sure that if we have this in Suricata ppl will be interested in
>>>>>>> buying
>>>>>>> the more detailed databases as well.
>>>>>>>
>>>>>>> --
>>>>>>> ---------------------------------------------
>>>>>>> Victor Julien
>>>>>>> http://www.inliniac.net/
>>>>>>> PGP: http://www.inliniac.net/victorjulien.asc
>>>>>>> ---------------------------------------------
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Oisf-devel mailing list
>>>>>>> Oisf-devel at openinfosecfoundation.org
>>>>>>> https://lists.openinfosecfoundation.org/mailman/listinfo/oisf-devel
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Regards,
>>>>>> Peter Manev
>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> Oisf-devel mailing list
>>>>>> Oisf-devel at openinfosecfoundation.org
>>>>>> https://lists.openinfosecfoundation.org/mailman/listinfo/oisf-devel
>>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> Regards,
>>>> Peter Manev
>>>>
>>>>
>>>
>>
>


-- 
Regards,
Peter Manev
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