[PATCH net-next v1 2/2] tools/net/ynl: Add multi message support to ynl

[Donald Hunter <donald.hunter@gmail.com>]

Add a "--multi <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}'

Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
---
 tools/net/ynl/cli.py     | 22 ++++++++++++++++---
 tools/net/ynl/lib/ynl.py | 47 +++++++++++++++++++++++++++-------------
 2 files changed, 51 insertions(+), 18 deletions(-)

diff --git a/tools/net/ynl/cli.py b/tools/net/ynl/cli.py
index f131e33ac3ee..1b8f87b472ba 100755
--- a/tools/net/ynl/cli.py
+++ b/tools/net/ynl/cli.py
@@ -19,13 +19,23 @@ class YnlEncoder(json.JSONEncoder):
 
 
 def main():
-    parser = argparse.ArgumentParser(description='YNL CLI sample')
+    description = """
+    YNL CLI utility - a general purpose netlink utility that uses YNL specs
+    to drive protocol encoding and decoding.
+    """
+    epilog = """
+    The --multi option can be repeated to include several 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)
+    parser.add_argument('--do', dest='do', metavar='OPERATION', type=str)
+    parser.add_argument('--dump', dest='dump', metavar='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',
@@ -40,6 +50,8 @@ def main():
     parser.add_argument('--output-json', action='store_true')
     parser.add_argument('--dbg-small-recv', default=0, const=4000,
                         action='store', nargs='?', type=int)
+    parser.add_argument('--multi', dest='multi', nargs=2, action='append',
+                        metavar=('OPERATION', 'JSON_TEXT'), type=str)
     args = parser.parse_args()
 
     def output(msg):
@@ -73,6 +85,10 @@ 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) for item in args.multi ]
+            reply = ynl.do_multi(ops)
+            output(reply)
     except NlError as e:
         print(e)
         exit(1)
diff --git a/tools/net/ynl/lib/ynl.py b/tools/net/ynl/lib/ynl.py
index 557ef5a22b7d..cecd89db7d58 100644
--- a/tools/net/ynl/lib/ynl.py
+++ b/tools/net/ynl/lib/ynl.py
@@ -927,16 +927,11 @@ class YnlFamily(SpecFamily):
 
       return op['do']['request']['attributes'].copy()
 
-    def _op(self, method, vals, flags=None, dump=False):
-        op = self.ops[method]
-
+    def _encode_message(self, op, vals, flags, req_seq):
         nl_flags = Netlink.NLM_F_REQUEST | Netlink.NLM_F_ACK
         for flag in flags or []:
             nl_flags |= flag
-        if dump:
-            nl_flags |= Netlink.NLM_F_DUMP
 
-        req_seq = random.randint(1024, 65535)
         msg = self.nlproto.message(nl_flags, op.req_value, 1, req_seq)
         if op.fixed_header:
             msg += self._encode_struct(op.fixed_header, vals)
@@ -944,8 +939,20 @@ class YnlFamily(SpecFamily):
         for name, value in vals.items():
             msg += self._add_attr(op.attr_set.name, name, value, search_attrs)
         msg = _genl_msg_finalize(msg)
+        return msg
 
-        self.sock.send(msg, 0)
+    def _ops(self, ops):
+        reqs_by_seq = {}
+        req_seq = random.randint(1024, 65535)
+        payload = b''
+        for (method, vals, flags) in ops:
+            op = self.ops[method]
+            msg = self._encode_message(op, vals, flags, req_seq)
+            reqs_by_seq[req_seq] = (op, msg)
+            payload += msg
+            req_seq += 1
+
+        self.sock.send(payload, 0)
 
         done = False
         rsp = []
@@ -954,8 +961,9 @@ class YnlFamily(SpecFamily):
             nms = NlMsgs(reply, attr_space=op.attr_set)
             self._recv_dbg_print(reply, nms)
             for nl_msg in nms:
-                if nl_msg.extack:
-                    self._decode_extack(msg, op, nl_msg.extack)
+                if nl_msg.extack and nl_msg.nl_seq in reqs_by_seq:
+                    (req_op, req_msg) = reqs_by_seq[nl_msg.nl_seq]
+                    self._decode_extack(req_msg, req_op, nl_msg.extack)
 
                 if nl_msg.error:
                     raise NlError(nl_msg)
@@ -963,13 +971,15 @@ class YnlFamily(SpecFamily):
                     if nl_msg.extack:
                         print("Netlink warning:")
                         print(nl_msg)
+                    del reqs_by_seq[nl_msg.nl_seq]
                     done = True
                     break
 
                 decoded = self.nlproto.decode(self, nl_msg)
+                rsp_op = self.rsp_by_value[decoded.cmd()]
 
                 # Check if this is a reply to our request
-                if nl_msg.nl_seq != req_seq or decoded.cmd() != op.rsp_value:
+                if nl_msg.nl_seq not in reqs_by_seq or decoded.cmd() != rsp_op.rsp_value:
                     if decoded.cmd() in self.async_msg_ids:
                         self.handle_ntf(decoded)
                         continue
@@ -977,19 +987,26 @@ class YnlFamily(SpecFamily):
                         print('Unexpected message: ' + repr(decoded))
                         continue
 
-                rsp_msg = self._decode(decoded.raw_attrs, op.attr_set.name)
+                rsp_msg = self._decode(decoded.raw_attrs, rsp_op.attr_set.name)
                 if op.fixed_header:
-                    rsp_msg.update(self._decode_struct(decoded.raw, op.fixed_header))
+                    rsp_msg.update(self._decode_struct(decoded.raw, rsp_op.fixed_header))
                 rsp.append(rsp_msg)
 
         if not rsp:
             return None
-        if not dump and len(rsp) == 1:
+        if not Netlink.NLM_F_DUMP in flags and len(rsp) == 1:
             return rsp[0]
         return rsp
 
+    def _op(self, method, vals, flags):
+        ops = [(method, vals, flags)]
+        return self._ops(ops)
+
     def do(self, method, vals, flags=None):
-        return self._op(method, vals, flags)
+        return self._op(method, vals, flags or [])
 
     def dump(self, method, vals):
-        return self._op(method, vals, [], dump=True)
+        return self._op(method, vals, [Netlink.NLM_F_DUMP])
+
+    def do_multi(self, ops):
+        return self._ops(ops)
-- 
2.44.0