Re: Writtign to audit with an application

Steve Grubb
2007-03-17T20:59:20Z

On Saturday 17 March 2007 14:54:54 geckiv wrote:
> I was wondering if anyone had a good example of how to write to the
> audit log on linux for a custom application wanting to log events.

There's several examples in trusted apps. But its really simple to do. This is
from aide:

#ifdef WITH_AUDIT
if(nadd!=0||nrem!=0||nchg!=0){
int fd=audit_open();
if (fd>=0){
char msg[64];

snprintf(msg, sizeof(msg), "added=%ld removed=%ld changed=%ld",
nadd, nrem, nchg);

if (audit_log_user_message(fd, AUDIT_ANOM_RBAC_INTEGRITY_FAIL,
msg, NULL, NULL, NULL, 0)<=0)
#ifdef HAVE_SYSLOG
syslog(LOG_ERR, "Failed sending audit message:%s", msg);
#else
;
#endif
close(fd);
}

Being that I don't know what your app is doing, I'd say that you should use
the AUDIT_TRUSTED_APP event type. Also try to follow guidelines so that it
can be parsed correctly by tools:

http://people.redhat.com/sgrubb/audit/audit-parse.txt

> Does it write to the demon then write to the /var/log/auit/audit.log?

No, it sends it to the kernel which decides what to do with it.

> Also how do yo set this up so not just any one or any process write to that
> log?

The audit system is intended to be high integrity, meaning that its not able
to be written to by ordinary users. You have to have CAP_AUDIT_WRITE in order
to write to the audit system.

-Steve