How to debug SASL2 and its plugin?

[Xu, Qiang (FXSGSC)]

> -----Original Message-----
> From: 
> cyrus-sasl-bounces+qiang.xu=fujixerox.com at lists.andrew.cmu.edu
>  
> [mailto:cyrus-sasl-bounces+qiang.xu=fujixerox.com at lists.andrew
> .cmu.edu] On Behalf Of Xu, Qiang (FXSGSC)
> Sent: Wednesday, August 05, 2009 5:12 PM
> To: cyrus-sasl at lists.andrew.cmu.edu
> Subject: How to debug SASL2 and its plugin?
> 
> I am investigating the SASL LDAP binding failure when 
> Kerberos server is configured with IPv6 address. But I don't 
> know how to open SASL logs, especially its GSSAPI plugin 
> (libgssapiv2.so) logs.
> 
> Could anybody give me some suggestions?

Looking at "sasl.h", I found there are 7 log levels: 
===================================================
/* Logging levels for use with the logging callback function. */
#define SASL_LOG_NONE  0	/* don't log anything */
#define SASL_LOG_ERR   1	/* log unusual errors (default) */
#define SASL_LOG_FAIL  2	/* log all authentication failures */
#define SASL_LOG_WARN  3	/* log non-fatal warnings */
#define SASL_LOG_NOTE  4	/* more verbose than LOG_WARN */
#define SASL_LOG_DEBUG 5	/* more verbose than LOG_NOTE */
#define SASL_LOG_TRACE 6	/* traces of internal protocols */
#define SASL_LOG_PASS  7	/* traces of internal protocols, including
				 * passwords */
===================================================
Which level can give maximum log information? And how to use them?

My knowledge of SASL is newbie level, so please shed some light on the log issue.

Thanks,
Xu Qiang