[PATCH iw 1/4] iw: nl80211: add NLA_F_NESTED to nla_nest_start() with older libnl versions

It is noticed in Kernel version 5.14.0-rc4+, that when sending the NL cmd
NL80211_CMD_SET_TID_CONFIG with nested attrs under NL80211_ATTR_TID_CONFIG,
kernel returnes a response with the error "NLA_F_NESTED is missing".

 $ sudo ./iw dev wlan0 set tidconf tids 0x1 ampdu on
 kernel reports: NLA_F_NESTED is missing
 command failed: Invalid argument (-22))

Fix this by setting NLA_F_NESTED flag everytime when using nla_nest_start()
library function. This is needed to make cfg80211 allow the nl80211 command
NL80211_ATTR_TID_CONFIG in the new kernel versions that enforce netlink
attribute policy validation.

Signed-off-by: Gokul Sivakumar <redacted>
---
 iw.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/iw.h b/iw.h
index a118f5b..545fd0e 100644
--- a/iw.h
+++ b/iw.h

@@ -11,6 +11,11 @@
 #include "nl80211.h"
 #include "ieee80211.h"
 
+#ifndef NL_CAPABILITY_VERSION_3_5_0
+#define nla_nest_start(msg, attrtype) \
+       nla_nest_start(msg, NLA_F_NESTED | (attrtype))
+#endif
+
 /* support for extack if compilation headers are too old */
 #ifndef NETLINK_EXT_ACK
 #define NETLINK_EXT_ACK 11

-- 
2.25.1