/*
Copyright 1990, Daniel J. Bernstein. All rights reserved.

Please address any questions or comments to the author at brnstnd@acf10.nyu.edu.
*/

The #include's should be rewritten.

All functions return 0 on success.

Environment variables: KRB5RCACHETYPE, KRB5RCACHENAME, KRB5RCACHEDIR,
and TMPDIR. Obsolete: KRB5RCACHE.

All header files are both ANSI-compatible and K&R-compatible. The .c files
are only ANSI compatible. Everything passes gcc -Wall -ansi -pedantic.

Strings are freed using FREE(), which is defined in terms of free(). 

The error header files should be redone.

The header files don't use __ because that's reserved.

Each .c file assumes <malloc.h>. rc_io.c assumes fsync() and a gaggle of
error codes. These assumptions are not as portable as the code itself.


rcache.c:

The rcache.c compatibility interface's type registration is a no-op; it
simply passes the type name on to rc_base.h. rcache.h is obsolete; use
rc_base.h if possible.

There are some slight differences between rcache.c and the prototypes I
saw in krb/func-proto.h. Don't look at me, it's your interface.

rcache.c's get_name doesn't fill with zeros unless strncpy does.


rc_base.c:

It doesn't take linker magic to preregister types. Just change the
typehead initialization in rc_base.c, with an appropriate include file
setting the ops.


rc_dfl.c:

If NOIOSTUFF is defined when rc_dfl.c is compiled, all dfl rcaches will
be per-process. This is untested.

Provided that separate threads use separate rcaches, rc_dfl.c is safe
for multithreading.

Getting the name of a cache is only valid after it is created and before
it is closed. Recovering a cache is only valid after it has been created.

krb5_unparse_name had better produce a zero-terminated string.

rc_dfl.c isn't smart enough to try expunge/retry upon a malloc error.
Then again, such an error indicates that the whole system's about to die;
without real memory management there's no good solution.

HASHSIZE can be defined at compile time. It defaults to 997 in rc_dfl.c.
EXCESSREPS can be defined at compile time. It defaults to 30 in rc_dfl.c.

Hopefully adding a deltat to a time to compare to another time cannot
overflow.

In rc_dfl's struct dfl_data, the name field is never freed, even though
it may be malloced by io_creat on a generate-name call. This should not
be a problem: a single process should not be opening and closing many
rcaches. One fix would be another field to indicate whether the string
was malloced or not; normally this is an unstated characteristic of a
char pointer, but here it would have to be explicit.


rc_io.c:

rc_io.c assumes that siginterrupt() is not set. If siginterrupt() is set
and a signal occurs during, say, close(), then the close will fail.

On a machine without fsync() you might as well not use the disk at all.