When reading from netlink-socket fails with NLE_NOMEM, messages were
lost. In this case the cache must be resynced and all pending messages
from the socket are rejected via "event_handler_recvmsgs (platform, FALSE)".
In this case, we don't want to handle the received messages as the
cache anyway needs to resync. However, we are still interested in
all queued ACKs that are there.
We are also interested in RTM_NEWADDR messages which we use to detect
kernel support via _support_kernel_extended_ifa_flags_detect().
Coverity: CID 59378 (#1 of 1): Nesting level does not match indentation
(NESTING_INDENT_MISMATCH) This statement is indented to column 41, as if
it were nested within the preceding parent statement, but it is not.
When deleting an object, we allow failure to delete a non-existing object.
Thus, the only thing we care about is whether the object is no longer
present after deletion. Adjust the return values to reflect that.
The idea was allowing pending delayed-actions and process them in an
idle handler. We dont want to do that, because whenever platform code
returns, we want to have no pending actions -- because otherwise the
platform cache might be in an inconsistent state.
Just drop it.
We would not expect that delayed_action_handle_all() is called recursively.
Assert against that. If we ever happen to call it recursively, we would
need to take care of properly avoiding infinite loops or deep call
stacks.
Track pending netlink requests and properly report the resulting errno
back.
Currently we send only requests in do_request_link() and do_request_all().
These callers don't actually care about the result, all they care that the
request is answered before returning back from platform code to the caller.
Thus, up to now the tracking of the sequence number was pretty simple.
Later we also want to get the errno from a request, thus rework sending
requests to also remember about outstanding sequence numbers and
properly track muliple parallel requests.
Later the synchronous actions (e.g. add-link) will also be handled
via the asynchronous socket.
Calling nl_recvmsgs_default() leads dirctly to recvmsgs() from
"nl.c". This functions reads messages (recvmsg) in a loop and
invokes the callbacks.
Later we want to merge nlh and nlh_event, meaning that we must
anticipate parsing unrelated messages while waiting for an ACK.
While that would be possible by registering different callbacks
and letting them interact, it is actually more complicated. Just
assume full control over the message parsing.
Basically, copy recvmsgs() to event_handler_recvmsg(). For now just
copy the function and do little adjustment (to show the similarity
to the original). Cleanup follows.
The macro EWOULDBLOCK is another name for EAGAIN; they are always the
same in the GNU C Library.
https://www.gnu.org/savannah-checkouts/gnu/libc/manual/html_node/Error-Codes.html
Otherwise, we would need a workaround for EWOULDBLOCK too, because
libnl maps that to NLE_FAILURE. So we would have to detect EAGAIN
as (nle == -NLE_FAILURE && errno == EWOULDBLOCK).
When the errno was accidentally set to EAGAIN or EWOULDBLOCK,
we would only read one single message and return that there is
nothing to read.
This means, if there were more then one messages ready to read,
we would only read the first one and return to the main-loop
(which then again calls back to platform as more data is ready
to be read).
Link related functions should have a "nm_platform_link" prefix. Rename.
Naming is a subjective matter and one might argue that omitting
the "link" part from the name is shorter and even preferred.
However, I think functions related to links should have a common
prefix as the underlyings are strongly related.
Let the link-add functions return the internal pointer to the platform
link object. Similar to link-get, which doesn't copy the link either.
Also adjust the sole users of the add-functions (create-and-realize)
to take the pointer.
Eventually we still copy the returned data, because accessing platform can
invalidate the returned pointer. Thus we don't actually safe any copying
by this (at least every use of the function currently leads to the data
being copied).
Still change it, because I think the API of NMPlatform should look like that.
