First, there is a memory leak - when the crypto functions fail,
hexresult was not freed. Second, in that error case, the return value
is simply passed up to the caller, ignoring the different meanings of
0 and 1 between crypto and pknock.
Some functions like the crypto init or proc_mkdir do not return an
error value. Replace the -1, which is actually EPERM, and looks a
little out of place, and use ENXIO instead. (After all, the requested
objects were not there after the request of initialization.)
Since pr_debug depends on #if DEBUG anyway, there is no need to
contain DEBUGP/pk_debug within a further if. Rename from DEBUGP to
pk_debug, because DEBUGP is flagged by Xtables-addons (- and that's
good so, because often DEBUGPs should have been pr_debug instead).
The printk calls were protected using #if DEBUG anyway, so they can
just be changed to pr_debug. pr_debug also depends on #if DEBUG, and
takes care of the module prefix.
If DEBUG was not defined, and no rule was effectively found, the
"rule" variable may still be non-NULL, and possibly cause deletion.
Therefore, always check for the rule having been found.
