netlink: add NLA_POLICY_MAX_LEN macro

Similarly to NLA_POLICY_MIN_LEN, NLA_POLICY_MAX_LEN defines a policy
with a maximum length value.

The netlink generator for YAML specs has been extended accordingly.

Signed-off-by: Antonio Quartulli <antonio@openvpn.net>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://patch.msgid.link/20241029-b4-ovpn-v11-1-de4698c73a25@openvpn.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/net/netlink.h b/include/net/netlink.h
index db6af207287c839408c58cb28b82408e0548eaca..2dc671c977ff3297975269d236264907009703d3 100644 (file)
--- a/include/net/netlink.h
+++ b/include/net/netlink.h
@@ -469,6 +469,7 @@ struct nla_policy {
        .max = _len                                             \
 }
 #define NLA_POLICY_MIN_LEN(_len)       NLA_POLICY_MIN(NLA_BINARY, _len)
+#define NLA_POLICY_MAX_LEN(_len)       NLA_POLICY_MAX(NLA_BINARY, _len)
 
 /**
  * struct nl_info - netlink source information

diff --git a/tools/net/ynl/ynl-gen-c.py b/tools/net/ynl/ynl-gen-c.py
index 1a825b4081b222cf97eb73f01a2a5c1ffe47cd5c..aa22eb0924754f38ea0b9e68a1ff5a55d94d6717 100755 (executable)
--- a/tools/net/ynl/ynl-gen-c.py
+++ b/tools/net/ynl/ynl-gen-c.py
@@ -481,7 +481,7 @@ class TypeBinary(Type):
             pass
         elif len(self.checks) == 1:
             check_name = list(self.checks)[0]
-            if check_name not in {'exact-len', 'min-len'}:
+            if check_name not in {'exact-len', 'min-len', 'max-len'}:
                 raise Exception('Unsupported check for binary type: ' + check_name)
         else:
             raise Exception('More than one check for binary type not implemented, yet')
@@ -492,6 +492,8 @@ class TypeBinary(Type):
             mem = 'NLA_POLICY_EXACT_LEN(' + self.get_limit_str('exact-len') + ')'
         elif 'min-len' in self.checks:
             mem = '{ .len = ' + self.get_limit_str('min-len') + ', }'
+        elif 'max-len' in self.checks:
+            mem = 'NLA_POLICY_MAX_LEN(' + self.get_limit_str('max-len') + ')'
 
         return mem