This patch adds new cache find api
nl_cache_find api was suggested by Thomas.
Unlike nl_cache_search, this patch uses
nl_object_match_filter() to look for an
object match.
Am not sure this matches what was decided
on the list few weeks back. I will be happy
to make any changes.
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
This patch adds the required structures and access functions to create
and manage hashtables for netlink cache objects
Signed-off-by: Shrijeet Mukherjee <shm@cumulusnetworks.com>
Signed-off-by: Nolan Leake <nolan@cumulusnetworks.com>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Reviewed-by: Wilson Kok <wkok@cumulusnetworks.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
This patch adds support to update a cache object during cache_include instead
of the current approach of deleting the original object and adding a new one.
This operation is conditional on the object implementing the operation. If
the update is not successful, cache_include falls back to the existing cache
inclusion process of deleting and adding the object.
It adds a new object operation called oo_update. oo_update takes two objects
as arguments, first being the existing cache object that needs update, the
second argument being the new object. Currently it is left to the implementor
to use the msg type to decide wether to delete or add the new object attributes
to the old one. But the operation type or msg type can be easily made part of the
object arguments.
The motivation for this change is explained below in the context of including
support for AF_BRIDGE objects into the link cache.
libnl today deletes an object before it includes an identical object.
But for some objects like the AF_BRIDGE objects this does not work well.
link cache uses the ifindex as its key in object searches.
If link cache were to support AF_BRIDGE family objects, todays implementation,
- will replace the original link object with the bridge port link object
for add notifications
- And a bridge port delete notification from kernel would delete the
link object from the cache leaving the cache without the link object
until the kernel sends another notification for that link
The bridge port link notification contains some base link object attributes
plus bridge specific protocol info attributes. In such cases we think an
operation to update the existing object in place in cache might be useful.
This can be made to work for AF_INET6 link objects too.
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Reviewed-by: Nolan Leake <nolan@cumulusnetworks.com>
Reviewed-by: Shrijeet Mukherjee <shm@cumulusnetworks.com>
Reviewed-by: Wilson Kok <wkok@cumulusnetworks.com>
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!
