tools/net/ynl: Add multi message support to ynl

Add a "--multi <do-op> <json>" command line to ynl that makes it
possible to add several operations to a single netlink request payload.
The --multi command line option is repeated for each operation.

This is used by the nftables family for transaction batches. For
example:

./tools/net/ynl/cli.py \
 --spec Documentation/netlink/specs/nftables.yaml \
 --multi batch-begin '{"res-id": 10}' \
 --multi newtable '{"name": "test", "nfgen-family": 1}' \
 --multi newchain '{"name": "chain", "table": "test", "nfgen-family": 1}' \
 --multi batch-end '{"res-id": 10}'
[None, None, None, None]

It can also be used for bundling get requests:

./tools/net/ynl/cli.py \
 --spec Documentation/netlink/specs/nftables.yaml \
 --multi gettable '{"name": "test", "nfgen-family": 1}' \
 --multi getchain '{"name": "chain", "table": "test", "nfgen-family": 1}' \
 --output-json
[{"name": "test", "use": 1, "handle": 1, "flags": [],
 "nfgen-family": 1, "version": 0, "res-id": 2},
 {"table": "test", "name": "chain", "handle": 1, "use": 0,
 "nfgen-family": 1, "version": 0, "res-id": 2}]

Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20240418104737.77914-4-donald.hunter@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 22 insertions, 3 deletions

diff --git a/tools/net/ynl/cli.py b/tools/net/ynl/cli.py
index f131e33ac3ee..058926d69ef0 100755
--- a/tools/net/ynl/cli.py
+++ b/tools/net/ynl/cli.py
@@ -19,13 +19,28 @@ class YnlEncoder(json.JSONEncoder):
 
 
 def main():
-    parser = argparse.ArgumentParser(description='YNL CLI sample')
+    description = """
+    YNL CLI utility - a general purpose netlink utility that uses YAML
+    specs to drive protocol encoding and decoding.
+    """
+    epilog = """
+    The --multi option can be repeated to include several do operations
+    in the same netlink payload.
+    """
+
+    parser = argparse.ArgumentParser(description=description,
+                                     epilog=epilog)
     parser.add_argument('--spec', dest='spec', type=str, required=True)
     parser.add_argument('--schema', dest='schema', type=str)
     parser.add_argument('--no-schema', action='store_true')
     parser.add_argument('--json', dest='json_text', type=str)
-    parser.add_argument('--do', dest='do', type=str)
-    parser.add_argument('--dump', dest='dump', type=str)
+
+    group = parser.add_mutually_exclusive_group()
+    group.add_argument('--do', dest='do', metavar='DO-OPERATION', type=str)
+    group.add_argument('--multi', dest='multi', nargs=2, action='append',
+                       metavar=('DO-OPERATION', 'JSON_TEXT'), type=str)
+    group.add_argument('--dump', dest='dump', metavar='DUMP-OPERATION', type=str)
+
     parser.add_argument('--sleep', dest='sleep', type=int)
     parser.add_argument('--subscribe', dest='ntf', type=str)
     parser.add_argument('--replace', dest='flags', action='append_const',
@@ -73,6 +88,10 @@ def main():
         if args.dump:
             reply = ynl.dump(args.dump, attrs)
             output(reply)
+        if args.multi:
+            ops = [ (item[0], json.loads(item[1]), args.flags or []) for item in args.multi ]
+            reply = ynl.do_multi(ops)
+            output(reply)
     except NlError as e:
         print(e)
         exit(1)