|CREDENTIALS(9F)||Kernel Functions for Drivers||CREDENTIALS(9F)|
Most users do not need to create new credentials. Instead, users should generally use the credentials of the executing context.
This interface is primarily intended for services that must perform operations on behalf of multiple remotely authenticated users, whose authentication context is unrelated to the context of the executing thread or process. Drivers MUST NOT create new credentials. Drivers should use the provided credential.
For functions that do not return new credentials, if the
credentials will be used outside of their context (i.e. if the output of
zone_kcred() is referenced outside of the zone), then one should use
ensure that the credentials remain valid.
CRED() function returns the credential of the calling thread. Its contents depend on the calling context (user, kernel, interrupt).
crdup() returns a newly-allocated copy of cr with reference count of 1. It sleeps until the allocation succeeds.
crfree() releases a reference to cr. If this is the last reference, the credential is destroyed.
crhold() takes a reference to cr.
E: basic,proc_secflags I: basic,proc_secflags P: basic,proc_secflags L: all
NET_MAC_AWARE is set in the credential's
flags. It is not marked privilege-aware.
kcred will never be freed by the system.
zone_kcred() function returns the root credential of the zone to which the calling thread belongs. This cred is derived from the global kcred, minus any privileges denied to the zone.
crget() function returns a copy of
zone_kcred() suitable for modification by the caller. This is useful for obtaining a default, well-initialized credential in the appropriate zone context, that is free of privileges or limitations of the originating thread. It must be freed with
crfree(). It sleeps until the allocation succeeds.
zone_kcred() are not privilege-aware, and have all IDs set to 0. This causes their Limit set to be used in place of the Effective and Permitted sets, which significantly expands their privileges.
If the output of
crget() is not later
marked as privilege aware, and its UID is not set to a non-zero value, then
its Limit set will be used in place of its Effective and Permitted sets,
significantly expanding its privileges. Callers should either mark the
credential as privilege-aware, reduce the Limit set appropriately, or ensure
that they intend for zero-uid users to have expanded privileges.
CRED() are not suitable for modfication by the
caller. Callers must use
crdup() to create a copy of
these credentials that are suitable for modification.
crget() must take care to ensure that the calling
thread is executing in the context of the appropriate zone. If the thread is
performing work on behalf of a different zone, or if one is uncertain of the
zone context of the calling thread, then one should find the appropriate
zone by other means, and reference zone->zone_kcred
CRED() return a pointer to a cred_t that should not be modified.
crdup() return a pointer to a newly allocated
crget() can never fail, and always return a valid
|August 21, 2020||OmniOS|