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From: Johannes Berg <johannes@sipsolutions.net>
To: linux-wireless@vger.kernel.org,
	Stephen Hemminger <stephen@networkplumber.org>,
	netdev@vger.kernel.org
Cc: David Ahern <dsahern@gmail.com>
Subject: [PATCH 1/3] libnetlink: add rtattr_for_each_nested() iteration macro
Date: Mon, 24 Aug 2020 19:51:06 +0200	[thread overview]
Message-ID: <20200824175108.53101-1-johannes@sipsolutions.net> (raw)

This is useful for iterating elements in a nested attribute,
if they're not parsed with a strict length limit or such.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
---
 include/libnetlink.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/libnetlink.h b/include/libnetlink.h
index e27516f7648f..0d4a9f29afbd 100644
--- a/include/libnetlink.h
+++ b/include/libnetlink.h
@@ -284,4 +284,9 @@ int rtnl_from_file(FILE *, rtnl_listen_filter_t handler,
  * messages from dump file */
 #define NLMSG_TSTAMP	15
 
+#define rtattr_for_each_nested(attr, nest) \
+	for ((attr) = (void *)RTA_DATA(nest); \
+	     RTA_OK(attr, RTA_PAYLOAD(nest) - ((char *)(attr) - (char *)RTA_DATA((nest)))); \
+	     (attr) = RTA_TAIL((attr)))
+
 #endif /* __LIBNETLINK_H__ */
-- 
2.26.2


             reply	other threads:[~2020-08-24 17:51 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-24 17:51 Johannes Berg [this message]
2020-08-24 17:51 ` [PATCH 2/3] libnetlink: add nl_print_policy() helper Johannes Berg
2020-10-25 21:23   ` Stephen Hemminger
2020-08-24 17:51 ` [PATCH 3/3] genl: ctrl: support dumping netlink policy Johannes Berg
2020-08-25  3:36 ` [PATCH 1/3] libnetlink: add rtattr_for_each_nested() iteration macro David Ahern

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