[bug?] Crash of hobbitsvc.cgi on trends column display 🔗 link

Hi Henrik,

Yesterday I upgraded my hobbit server to take advantage of the
all-in-one corrections, plus the "split-ncv" feature (have a peek in
your spambox to see my message about this :)). I then found a bug
that did not show up on the test host, so I rolled back.

Since then, hobbitsvc.cgi segfaults when I click on the trends column
(renamed _graphs in my setup) :

http://monitor/hobbit-cgi/bb-hostsvc.sh?HOST=somehost.dom&SERVICE=_graphs

Here's gdb output :


#0  bbh_find_item (host=0x8088210, item=BBH_DISPLAYNAME) at
loadhosts.c:160
#1  0x0804e652 in rrdlink_text (host=0x807f980, rrd=0x80881f0,wantmeta=HG_PLAIN_LINK) at hobbitsvc-trends.c:120
#2  0x0804eb99 in generate_trends (hostname=0x80769d8 "somehost.dom") at hobbitsvc-trends.c:288
#3  0x08049feb in do_request () at hobbitsvc.c:216
#4  0x0804aeb6 in main (argc=1, argv=0xbf935594) at hobbitsvc.c:518

just before the crash, I have :

i=0
host->elems gives "Cannot access memory at address 0x0"
item=BBH_DISPLAYNAME
bbh_item_key[item]="NAME:"

160             while (host->elems[i] && strncasecmp(host->elems[i],bbh_item_key[item], strlen(bbh_item_key[item]))) i++;


Can it come from a missing "something" in the configuration ? Can it
crash because of corrupted rrd files ? I continue my investigations,
but you sure can help :).


[oh, I found another small bug, not severe at all: when running
hobbitsvc.cgi from the command line, it segfaults if SCRIPT_NAME is not
set. Maybe it should set SCRIPT_NAME to a sensible default or at least
exit grcefully]


-- 
Charles Goyard - user-98f9625a7a59@xymon.invalid - (+33) 1 45 38 01 31

Yes, the cgis are not all checking that their environment.

I was about to provide patches so they at least call envcheck() as some 
of the cgis are using it.

Something like this will do the trick for hobbigraph.c for instance

--- hobbit-4.2.0-allinone/web/hobbitgraph.c     2006-11-08 
14:08:15.000000000 +0000
+++ hobbit-4.2.0-sanity/web/hobbitgraph.c       2006-11-28 
15:16:10.492252944 +0000
@@ -490,6 +490,13 @@
         char *okuri, *p;
         int urilen;

+       /* first of all, sanity checks */
+       char *reqenv[] = {
+               "BBHOME", "BBRRDS", "SCRIPT_NAME", "RRDHEIGHT",
+               "RRDWIDTH", "HTMLCONTENTTYPE", NULL
+       };
+       envcheck(reqenv);
• graphwidth = atoi(xgetenv("RRDWIDTH"));
         graphheight = atoi(xgetenv("RRDHEIGHT"));

Cheers,
Gildas

Hi again,

As an extra info, I found the reason why the program crashes :

in loadhosts.c, when there :

if (result || !host->defaulthost || (strcasecmp(host->bbhostname, ".default.") == 0))
	return result;
else
	return bbh_find_item(host->defaulthost, item);

I get in the "else". At that point, host->defaulthost is not null, but
points to garbage. I dont't get what the default host should be.


(btw, thanks for the patch Gildas)

-- 
Charles Goyard - user-98f9625a7a59@xymon.invalid - (+33) 1 45 38 01 31

Ok, I went thru the /web directory and edited the cgi to add the crude environment checking I've been talking on earlier. Compiled cgis have been tested individually without parameters and in line as drop-in replacements for the existing cgi, "it works for me".

This patch applies to a hobbit-4.2.0 with the all-in-one patch applied using "patch -p1 <sanity_check.patch".

As always, feedback are welcome

Cheers
Gildas

Charles Goyard wrote:

Hi,

Charles Goyard wrote :

ok, I figured all this out... I upgraded hobbit partially in the wrong
location. I had HOME for the hobbit user set to /home/hobbit/server
instead of /home/hobbit, so I partially screwed up my server.
Reinstalling correctly solves the problems.

Now my split-ncv feature (extensively debugged on my personal box) is on
my production server. I'll submit the patch next week if anything goes
well.

Quick question: which implementation do you prefer :
SPLITNCV_sometest="data1:GAUGE...."
or
NCV_sometest="data1:GAUGE...."
SPLITNCV="sometest,someothertest..."


Kind regards,

-- 
Charles Goyard - user-98f9625a7a59@xymon.invalid - (+33) 1 45 38 01 31

Hi,

I'm currently running Hobbit (4.2.0) and devmon (0..2) monitor a  number of hosts and appliances.
All is working well, however, i'd like to add the functionality of  trend graphing to the data collected
from devmon.

I believe that hobbit wont natively generate the rrd files using the  NCV directive.

Is there a known work around for this.

 From reading through the archives I found:
http://www.hobbitmon.com/hobbiton/2006/03/msg00097.html

Which seems to address the problem, but no details on how.

Any help appreciated.

Kind regards

Rob

Hi Rob

See the mail archieves ( from Jan 23 2007 ) for the devmon-support list.

The short answer is : Yes, it works. There is some quirks to the NCV parsing
of the message that you should be aware of - but it works.
This was also discussed last week here on the hobbit list.

Enjoy

/Torben

On 1/29/07, Rob Fuller <user-a31aae8297f6@xymon.invalid> wrote: