I'm filing the following self-reviewed case for Erik Nordmark. It
proposes changes to Consolidation Private interfaces which increase the
robustness of db_credp handling. A Patch release binding is requested.
The motivation for the changes are:
6619593 Simplify and strengthen db_credp handling
6619596 Add getpeerucred() support to SCTP SOCK_STREAM
PSARC 2002/188 ("Least Privilege for Solaris") introduced DB_CRED,
allocb_tmpl etc as follows:
--------------------------------------------------------------------------
|DB_CRED DB_CREDDEF |Consolidation |STREAMS |
| |Private |macros |
+-------------------------------------------+--------------+-------------+
|allocb_tmpl |Evolving |Kernel |
| | |function to |
| | |allocate mblk|
| | |from template|
+-------------------------------------------+--------------+-------------+
|allocb_cred allocb_cred_wait |Consolidation |Kernel |
| |Private |function to |
| | |allocate mblk|
| | |with cred |
+-------------------------------------------+--------------+-------------+
|mblk_setcred |Consolidation |Kernel |
| |Private |function to |
| | |set cred in |
| | |mblk |
--------------------------------------------------------------------------
This case implements the following changes:
- It removes the DB_CREDDEF macro.
- No changes to allocb_tmpl.
- allocb_cred, allocb_cred_wait, and mblk_setcred are modified to take an
additional pid_t argument (to more easily ensure that db_cpid and db_credp
are consistent)
- 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.
SCTP in PSARC 2003/586 introduced some consolidation private interfaces that
are modified by this case. Those are:
| struct sctp_upcalls_s | Consolidation Private | <inet/sctp_itf.h> |
| SCTP_ITF_VER | Consolidation Private | <inet/sctp_itf.h> |
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.
