dmsetup: fix 'dmsetup status' for crypt filling '0' in wrong area

Hi,

dmsetup tries to suppress encryption key of crypt target in the table by filling '0' in params buffer.
However, the code assumes the case for showing table only and will fill '0' beyond the params buffer when it's showing status, where the params is "".

The patch fixes it.
The suppression is not necessary for showing status as no encryption key is included in status line.

Thanks,

Jun'ichi Nomura, NEC Corporation of America

dmsetup tries to suppress encryption key of crypt target. However, the code overruns the params buffer if the command is showing 'status', in that case params is "".

---
 dmsetup/dmsetup.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Index: device-mapper.work/dmsetup/dmsetup.c
===================================================================
@@ -964,12 +964,14 @@ static int _status(int argc, char **argv
 			if (target_type) {
 
 			/* Suppress encryption key */
-			if (!_switches[SHOWKEYS_ARG] &&
+			if (cmd == DM_DEVICE_TABLE &&
+			    !_switches[SHOWKEYS_ARG] &&
 			    !strcmp(target_type, "crypt")) {
 				c = params;
 				while (*c && *c != ' ')
 					c++;
-				c++;
+				if (*c)
+					c++;
 				while (*c && *c != ' ')
 					*c++ = '0';
 			}

Hello, I was wondering if there were any kinds of design documents, etc... types of notes on how the device mapper event daemon was thought-up/designed? Or if anyone is working on documentation?

From what I've gathered so far (by reading the code) is that dmeventd is designed around a plug-in type model (and that LVM has a plugin for this that I could possibly trace through to see how this all works). Also, I've dug in enough to see that error event handling and failure handling for dmraid is not implemented (correct me if I'm wrong, please :) ) and that there is some very simple event handling for LVM (just userspace mirroring from what I've found)?

Ideally what I would like to help out with is developing a shared library for the dmeventd daemon for dmraid so events could be reported for the various raid levels. From what I understand Jonathan Brassow did the initial work on dmeventd and might be my best resource in finding implementation details.

Until I can put together a High-Level document that management can understand about dmeventd's current functionality I'm sort of in a catch 22...I am being tasked with adding functionality to this project, but can't start working until they know what is currently there and how it was designed. Any help with guidance would be greatly appreciated.

Brian Wood
Intel Corporation
Digital Enterprise Group
Manageability & Platform Software Division
[email protected]