Finally got rid of all the qdisc/class/cls code duplication in
the tc module API. The API takes care of allocation/freeing the
tc object specific data.
I hope I got it right this time.
In order for the interface to become more thread safe, the error
handling was revised to no longer depend on a static errno and
error string buffer.
This patch converts all error paths to return a libnl specific
error code which can be translated to a error message using
nl_geterror(int error). The functions nl_error() and
nl_get_errno() are therefore obsolete.
This change required various sets of function prototypes to be
changed in order to return an error code, the most prominent
are:
struct nl_cache *foo_alloc_cache(...);
changed to:
int foo_alloc_cache(..., struct nl_cache **);
struct nl_msg *foo_build_request(...);
changed to:
int foo_build_request(..., struct nl_msg **);
struct foo *foo_parse(...);
changed to:
int foo_parse(..., struct foo **);
This pretty much only leaves trivial allocation functions to
still return a pointer object which can still return NULL to
signal out of memory.
This change is a serious API and ABI breaker, sorry!
New netem-related functionality:
Added ability to save new settings to the kernel. In netem.c, the
netem_get_opts() stub has been replaced with netem_build_msg() which
manipulates the nl_msg data directly and returns an error code instead
of a new nl_msg. Modifications to qdisc_build() in qdisc.c and struct
rtnl_qdisc_ops were necessary for this.
Added support for getting/setting corruption probability/correlation.
Added support for setting a delay distribution.
Fixed tbf_msg_parser() to call tbf_alloc() instead of tbf_qdisc() to
prevent a seg fault.