The cache layer uses the message type array stored in the cache
ops to lookup which cache a message belongs to. Update to the
the message array with the resolved generic netlink id to make
it compatible with the caching API.
Allows to use nl_cache_refill() and others for generic netlink
based caches with dynamic generic netlink ids.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Introduces the functions genl_register_family() and
genl_unregister_family() to register a Generic Netlink family
which does not implement a cachable type.
API users can direct received messages into genl_handle_msg() which
will validate the messages and call the callback functions defined
in the commands definition.
See test/test-genl.c for an example on how to use it.
These functions deprecate the function genlmsg_data() which did not
allow to specify the length of the user header. Use of the new API
will make code much clearer. The old function is still kept around
for backwards compatibility but marked deprecated in the API reference.
The idea of a common handle is long revised and only misleading,
nl_handle really represents a socket with some additional
action handlers assigned to it.
Alias for nl_handle is kept for backwards compatibility.
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!
This interface was internal so far which required all code defining
caches to be compiled with the sources available.
In order to simplify the interface, the co_msg_parser prototype was
changed to take the struct nl_parser_param directly instead of a
void *. It used to be void * because the co_msg_parser was directly
passed as the NL_CB_VALID callback function.
Thomas Graf