dbpmda permissions

[Martins Innus <minnus@xxxxxxxxxxx>]

Hi,
    I am trying to write some QA for hotproc and ran into a stumbling 
block with dbpma in how it treats permissions.  I have a simple access 
check in hotproc where I check for the context of the requester to be 
root in order to allow stores and this seems to work fine with pmstore:
[vagrant@pcptest pcpdec]$ pmstore hotproc.control.config "uid=0"
hotproc.control.config old value="" new value="uid=0"
hotproc.control.config: pmStore: No permission to perform requested 
operation
[vagrant@pcptest pcpdec]$ sudo pmstore hotproc.control.config "uid=0"
hotproc.control.config old value="" new value="uid=0"
[vagrant@pcptest pcpdec]$ pmval -s 1 hotproc.control.config


But I can't get this to work at all with dbpmda:

[vagrant@pcptest pcpdec]$ sudo dbpmda -i
dbpmda> getdesc on
dbpmda> open pipe /var/lib/pcp/pmdas/proc/pmdaproc -d 3
Start pmdaproc PMDA: /var/lib/pcp/pmdas/proc/pmdaproc -d 3
dbpmda> store hotproc.control.config "uid=0"
PMID: 3.60.8
Getting description...
Sending Profile...
Getting Result Structure...
3.60.8: "" -> "uid=0"
Sending Result...
Error PDU: No permission to perform requested operation

As far as I can tell, all processes are running as root:

[vagrant@pcptest testsuite]$ ps -ef |grep pmda
root     20407  2253  0 21:23 pts/0    00:00:00 sudo dbpmda -i
root     20408 20407  0 21:23 pts/0    00:00:00 dbpmda -i
root     20410 20408  0 21:24 pts/0    00:00:00 
/var/lib/pcp/pmdas/proc/pmdaproc -d 3

I'm doing the root check in this way, adding a method to contexts.c:

int
proc_ctx_getuid(int ctx)
{
    proc_perctx_t *pp;

    if (ctx < 0 || ctx >= num_ctx)
    return -1;

    pp = &ctxtab[ctx];

    if ( (pp->state & CTX_ACTIVE) && (pp->state & CTX_USERID) )
    return pp->uid;
    else
    return -1;
}

And then returning a permission error if the return !=0.  I'll publish 
my full tree tomorrow but just wanted to see if this jumped out to 
anyone as a problem you've seen before.
Thanks

Martins