2007/670 db_credp update

[James Carlson]

Bill Sommerfeld writes:
>   - Adding two new Consolidation Private interfaces
>         cred_t *msg_getcred(mblk_t *, pid_t *);
>         cred_t *msg_extractcred(mblk_t *, pid_t *)
>     The pid_t pointer can be  NULL if the caller doesn't care.
> 
>     msg_getcred() finds the first non-NULL db_credp in
>     the message b_cont chain and returns it, plus any db_cpid in that mblk.
>     msg_extractcred() is a variant of msg_getcred() which clears the db_credp it
>     finds hence returns with a held cred_t (or NULL). That avoids a crhold/rele
>     pair in performance critical paths.

The behavior of msg_extractcred seems a little unclear.  Is it
possible for an mblk_t b_cont chain to have two or more mblk_t entries
with non-NULL db_credp?  If so, then extracting can have the strange
side-effect of uncovering old creds unless the function continues
through the rest of the b_cont chain, clearing out and discarding any
creds it finds.

> This fasttrack will add an additional function pointer, su_ucred, to the
> upcall structure in order to pass cred_t and pid_t from SCTP to sockfs,
> and as result of that addition we are increasing the SCTP_ITF_VER
> version number.

Version number?  Are there users of this interface outside of ON?

-- 
James Carlson, Solaris Networking              <james.d.carlson at sun.com>
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