TC uses all possible sub-message formats:
- nested attrs
- fixed headers + nested attrs
- fixed headers
- empty
Nested attrs are already supported for rt-link. Add support
for remaining 3. The empty and fixed headers ones are fairly
trivial, we can fake a Binary or Flags type instead of a Nest.
For fixed headers + nest we need to teach nest parsing and
nest put to handle fixed headers.
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://patch.msgid.link/20250520161916.413298-10-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reverse parsing lets YNL convert bad and missing attr pointers
from extack into a string like "missing attribute nest1.nest2.attr_name".
It's a feature that's unique to YNL C AFAIU (even the Python YNL
can't do nested reverse parsing). Add support for reverse-parsing
of sub-messages.
To simplify the logic and the code annotate the type policies
with extra metadata. Mark the selectors and the messages with
the information we need. We assume that key / selector always
precedes the sub-message while parsing (and also if there are
multiple sub-messages like in rt-link they are interleaved
selector 1 ... submsg 1 ... selector 2 .. submsg 2, not
selector 1 ... selector 2 ... submsg 1 ... submsg 2).
The rt-link sample in a subsequent changes shows reverse parsing
of sub-messages in action.
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://patch.msgid.link/20250515231650.1325372-8-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Adjust parsing and rendering appropriately to make sub-messages work.
Rendering is pretty trivial, as the submsg -> netlink conversion looks
like rendering a nest in which only one attr was set. Only trick
is that we use the enum value of the sub-message rather than the nest
as the type, and effectively skip one layer of nesting. A real double
nested struct would look like this:
[SELECTOR]
[SUBMSG]
[NEST]
[MSG1-ATTR]
A submsg "is" the nest so by skipping I mean:
[SELECTOR]
[SUBMSG]
[MSG1-ATTR]
There is no extra validation in YNL if caller has set the selector
matching the submsg type (e.g. link type = "macvlan" but the nest
attrs are set to carry "veth"). Let the kernel handle that.
Parsing side is a little more specialized as we need to render and
insert a new kind of function which switches between what to parse
based on the selector. But code isn't too complicated.
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://patch.msgid.link/20250515231650.1325372-7-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Classic netlink makes extensive use of flags. Support specifying
them the same way as attributes are specified (using a helper),
for example:
rt_link_newlink_req_set_nlflags(req, NLM_F_CREATE | NLM_F_ECHO);
Wrap the code up in a RenderInfo predicate. I think that some
genetlink families may want this, too. It should be easy to
add a spec property later.
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20250429154704.2613851-5-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Make sure the codegen calls the right YNL lib helper to start
the request based on family type. Classic netlink request must
not include the genl header.
Conversely don't expect genl headers in the responses.
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://patch.msgid.link/20250410014658.782120-10-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Dan, who's working on C++ YNL, pointed out that the C code
does not make policies const. Sprinkle some 'const's around.
Reported-by: Dan Melnic <dmm@meta.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Folks working on a C++ codegen would like to reuse the attribute
helpers directly. Add the few necessary casts, it's not too ugly.
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20240529192031.3785761-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Donald points out that we don't check for overflows.
Stash the length of the message on nlmsg_pid (nlmsg_seq would
do as well). This allows the attribute helpers to remain
self-contained (no extra arguments). Also let the put
helpers continue to return nothing. The error is checked
only in (newly introduced) ynl_msg_end().
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20240305185000.964773-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Most libmnl socket helpers can be replaced by direct calls to
the underlying libc API. We need portid, the netlink manpage
suggests we bind() address of zero.
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20240227223032.1835527-14-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
All YNL parsing callbacks take struct ynl_parse_arg as the argument.
Make that official by using a local callback type instead of mnl_cb_t.
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20240227223032.1835527-12-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ynl_recv_ack() is simple and it's the only user of mnl_cb_run().
Now that ynl_sock_read_msgs() exists it's actually less code
to use ynl_sock_read_msgs() instead of being special.
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20240227223032.1835527-10-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit f2ba1e5e22 ("tools: ynl-gen: stop generating common notification handlers")
removed the last caller of the parse_cb_run() helper.
We no longer need to export ynl_cb_array.
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20240227223032.1835527-8-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
All YNL parsing code expects a pointer to struct ynl_parse_arg AKA yarg.
For dump was pass in struct ynl_dump_state, which works fine, because
struct ynl_dump_state and struct ynl_parse_arg have identical layout
for the members that matter.. but it's a bit hacky.
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20240227223032.1835527-7-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Create helpers for accessing payloads of struct nlmsg.
Use them instead of the libmnl ones.
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20240227223032.1835527-5-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Don't use mnl attr helpers, we're trying to remove the libmnl
dependency. Create both signed and unsigned helpers, libmnl
had unsigned helpers, so code generator no longer needs
the mnl_type() hack.
The new helpers are written from first principles, but are
hopefully not too buggy.
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20240227223032.1835527-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The temporary auto-int helpers are not really correct.
We can't treat signed and unsigned ints the same when
determining whether we need full 8B. I realized this
before sending the patch to add support in libmnl.
Unfortunately, that patch has not been merged,
so time to fix our local helpers. Use the mnl* name
for now, subsequent patches will address that.
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20240227223032.1835527-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ynl.h has a growing amount of "internal" stuff, which may confuse
users who try to take a look at the external API. Currently the
internals are at the bottom of the file with a banner in between,
but this arrangement makes it hard to add external APIs / inline
helpers which need internal definitions.
Move internals to a separate header.
Link: https://lore.kernel.org/r/20231202211225.342466-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
