diff mbox series

[net-next,v8,1/3] netlink: Add nla_put_empty_nest helper

Message ID 20250214211255.14194-2-jdamato@fastly.com (mailing list archive)
State Accepted
Commit a127c18462ea619a1ace1f00540807e009dbf225
Delegated to: Netdev Maintainers
Headers show
Series netdev-genl: Add an xsk attribute to queues | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; GEN HAS DIFF 2 files changed, 35 insertions(+);
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 16 this patch: 16
netdev/build_tools success Errors and warnings before: 26 (+1) this patch: 26 (+1)
netdev/cc_maintainers success CCed 5 of 5 maintainers
netdev/build_clang success Errors and warnings before: 383 this patch: 383
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 2890 this patch: 2890
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 27 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 74 this patch: 74
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2025-02-15--18-00 (tests: 891)

Commit Message

Joe Damato Feb. 14, 2025, 9:12 p.m. UTC 
Creating empty nests is helpful when the exact attributes to be exposed
in the future are not known. Encapsulate the logic in a helper.

Signed-off-by: Joe Damato <jdamato@fastly.com>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
---
 v4:
   - new in v4

 include/net/netlink.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
diff mbox series

Patch

diff --git a/include/net/netlink.h b/include/net/netlink.h
index e015ffbed819..29e0db940382 100644
--- a/include/net/netlink.h
+++ b/include/net/netlink.h
@@ -118,6 +118,7 @@ 
  *   nla_nest_start(skb, type)		start a nested attribute
  *   nla_nest_end(skb, nla)		finalize a nested attribute
  *   nla_nest_cancel(skb, nla)		cancel nested attribute construction
+ *   nla_put_empty_nest(skb, type)	create an empty nest
  *
  * Attribute Length Calculations:
  *   nla_attr_size(payload)		length of attribute w/o padding
@@ -2240,6 +2241,20 @@  static inline void nla_nest_cancel(struct sk_buff *skb, struct nlattr *start)
 	nlmsg_trim(skb, start);
 }
 
+/**
+ * nla_put_empty_nest - Create an empty nest
+ * @skb: socket buffer the message is stored in
+ * @attrtype: attribute type of the container
+ *
+ * This function is a helper for creating empty nests.
+ *
+ * Returns: 0 when successful or -EMSGSIZE on failure.
+ */
+static inline int nla_put_empty_nest(struct sk_buff *skb, int attrtype)
+{
+	return nla_nest_start(skb, attrtype) ? 0 : -EMSGSIZE;
+}
+
 /**
  * __nla_validate_nested - Validate a stream of nested attributes
  * @start: container attribute