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 From:  Adam Nellemann <adam at nellemann dot nu>
 To:  "m0n0wall at lists dot m0n0 dot ch" <m0n0wall at lists dot m0n0 dot ch>
 Subject:  The traffic grapher - A problem and a question/comment
 Date:  Thu, 01 Apr 2004 20:38:08 +0200
Hi,

Thanks for the Beta Manuel, always nice to get new versions, 
especially when there are interessting new features to play around with :)

I was looking very much forward to try the new Traffic grapher, but 
unfortunatly it doesn't work for me :(

When I open the page, the plugin will show an empty graph, but then it 
pops up an error in IE, saying "Object expected", with a title of 
"Microsoft JScript runtime error". Pressing "OK" (only choice) removes 
the popup, but the graph, while visible, has no data plots. The same 
error is shown again if the interface is changed or the page is 
refreshed. Sometimes IE will even crash (I think this happens if I 
refresh before OK'ing the popup, not sure though?)

However since nobody else have reported similar problems, I must 
assume this has to do with my particular IE installation (which is 
sick in other ways too, so...) Unless someone else have experienced 
this and/or know how to solve the issue, I guess I'll have to wait for 
my upcomming hardware upgrade and the following reinstallation of Win2k.

= = =

So much for my problem. My question/comment is this:

I was a bit surprised to see this particular (SVG) solution used for 
the traffic grapher. Perhaps someone would care to elaborate on the 
reasons behind this choice?

Taking a stab at an answer myself: Am I correct in assuming that the 
use of SVG allow you to implement the m0n0wall side of the graph 
purely in PHP, with a minimum of processing taking place on the 
m0n0wall box, and without the need for any additional binaries?

Even if I can see the benefits from this (that is, if my guess was 
correct), there is a lot to be said for a solution that does not 
involve a particular plugin being installed on the client browser (as 
the posts about non-IE browser problems shows).

I understand that time and effort has already been put into this, and 
so it might be a bit late to suggest another approach, and I haste to 
add that I'm sure I, and most other users, will be perfectly happy 
with the current solution. So please don't take the suggestion below 
for anything other than it is. I wouldn't presume to know better than 
Manuel or anyone else working on the m0n0wall project. I'm far to 
impressed with the product as a whole for that :)

Personally though, I would consider an approach where a dynamically 
produced image (PNG or GIF) was used to show the graph(s), so as to 
avoid the need for a plugin and thus keeping the webGUI as compatible 
as possible. I'm rather sure there are a number of utilities 
available, that will produce such graph-images on the fly, given the 
right data (indeed this was the only way to do graphs, counters and 
other dynamic images, back when cgi-scripts were the only kind of HTML 
"plugin" available).

While I'm rather sure most such graph-producing programs would pose no 
security risk, nor impact the stability of m0n0wall, I do realise that 
they might use some resources, which could be a minor problem for some 
Soekriss users. But I get the impression that this new graph page 
wasn't intended for doing long-term statistical analysis, and so 
wouldn't be expected to remain active for extended periods (also the 
thread/process could be given a very low priority, ensuring anything 
performance related will be getting what it needs). That being said, 
I'm sure most such programs will be quite modest in their requirements 
(after all they were made to run on webservers, often serving 
individual images to a large number of concurrent users).

In case this approach is deemed unfeasible, I'd consider a solution 
similar to the current one, but using Shockwave Flash instead. At 
least this is a very common, and widely supported plugin. Some 
browsers (notably IE) even come with built-in Flash support, removing 
the need to install a plugin altogether. This way, users won't have to 
install a plugin they might not use for anything other than the 
m0n0wall graph (something you could argue could pose an entirely 
different kind of security and bug risk, albeit on the client box 
instead of m0n0wall).

There is also the issue of company policies regarding installation of 
plugins to consider, which will probably be less of an issue with 
Flash, and non-existent with the dynamic-PNG solution.

Finally, I'd like to comment on those posts suggesting that one use 
MRTG, Cacti, or whatever SNMP graphers are out there for any 
graphing-needs not catered to by the new m0n0wall graphs: While this 
does provide some very nice graphs and other features, there are a 
number of reasons why this isn't very optimal, or even feasible, for 
many m0n0wall users: First of all most of these work by servering HTML 
pages, and will thus require you to install and run a webserver, 
somewhat overkill if you otherwise have no use for this on your LAN. 
In addition they typically aren't exactly plug-n-play, making it a 
problem for some users to get it properly configured or even running 
at all, not to mention making sure the webserver isn't otherwise 
posing a security risk.

I have been able to find a few stand-alone SNMP clients, but none of 
these were any good. Thus I should think there will be a lot of users 
who would be very happy to be able to satisfy their "graphing needs" 
through whatever is provided in the m0n0wall webGUI, at least until 
someone decides to make a nice, small SNMP client with the necessary 
graphing features.

BTW: I'd be happy to produce such a util, only I would need some help 
with the SNMP part, and also: I'd find it more worthwhile, if there 
was a bit more information provided through SNMP from m0n0wall, making 
it possible to show a tad more than just in/out traffic for each 
interface (such as traffic per-host, -protocol, 
-shaper_rule/queue/pipe, and/or -firewall rule).

Just in case somebody is already working on (or considering) such a 
program: I've got some quite nice OpenGL graph code, which I'd be 
happy to share! I'm sure I could easily port it to a more compatible 
ANSI C++ version, if needed (currently a bit C++ Builder specific), 
and I'd of course be happy to help with the development if needed/wanted.

Anyway, just my two cents. And don't get me wrong: No matter how it is 
implemented, I'm a sucker for anything graphic and "blinkenlichten" 
and am very happy to see this particular feature making it into the 
beta (and hopefully the release at some point). Now, about that 
suggestion for a 3D screensaver in the m0n0wall webGUI... :))


Regards,

Adam.


P.S. Please excuse my longwindedness, can't help it I'm afraid :(