Merge branch 'nla_nest_start'

Michal Kubecek says:

====================
make nla_nest_start() add NLA_F_NESTED flag

One of the comments in recent review of the ethtool netlink series pointed
out that proposed ethnl_nest_start() helper which adds NLA_F_NESTED to
second argument of nla_nest_start() is not really specific to ethtool
netlink code. That is hard to argue with as closer inspection revealed that
exactly the same helper already exists in ipset code (except it's a macro
rather than an inline function).

Another observation was that even if NLA_F_NESTED flag was introduced in
2007, only few netlink based interfaces set it in kernel generated messages
and even many recently added APIs omit it. That is unfortunate as without
the flag, message parsers not familiar with attribute semantics cannot
recognize nested attributes and do not see message structure; this affects
e.g. wireshark dissector or mnl_nlmsg_fprintf() from libmnl.

This is why I'm suggesting to rename existing nla_nest_start() to different
name (nla_nest_start_noflag) and reintroduce nla_nest_start() as a wrapper
adding NLA_F_NESTED flag. This is implemented in first patch which is
mostly generated by spatch. Second patch drops ipset helper macros which
lose their purpose. Third patch cleans up minor coding style issues found
by checkpatch.pl in first patch.

We could leave nla_nest_start() untouched and simply add a wrapper adding
NLA_F_NESTED but that would probably preserve the state when even most new
code doesn't set the flag.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 17 insertions, 16 deletions

diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
index 3563acd5f92e..2427b672107a 100644
--- a/net/openvswitch/flow_netlink.c
+++ b/net/openvswitch/flow_netlink.c
@@ -856,7 +856,7 @@ static int vxlan_opt_to_nlattr(struct sk_buff *skb,
 	const struct vxlan_metadata *opts = tun_opts;
 	struct nlattr *nla;
 
-	nla = nla_nest_start(skb, OVS_TUNNEL_KEY_ATTR_VXLAN_OPTS);
+	nla = nla_nest_start_noflag(skb, OVS_TUNNEL_KEY_ATTR_VXLAN_OPTS);
 	if (!nla)
 		return -EMSGSIZE;
 
@@ -948,7 +948,7 @@ static int ip_tun_to_nlattr(struct sk_buff *skb,
 	struct nlattr *nla;
 	int err;
 
-	nla = nla_nest_start(skb, OVS_KEY_ATTR_TUNNEL);
+	nla = nla_nest_start_noflag(skb, OVS_KEY_ATTR_TUNNEL);
 	if (!nla)
 		return -EMSGSIZE;
 
@@ -1957,7 +1957,7 @@ static int nsh_key_to_nlattr(const struct ovs_key_nsh *nsh, bool is_mask,
 {
 	struct nlattr *start;
 
-	start = nla_nest_start(skb, OVS_KEY_ATTR_NSH);
+	start = nla_nest_start_noflag(skb, OVS_KEY_ATTR_NSH);
 	if (!start)
 		return -EMSGSIZE;
 
@@ -2040,14 +2040,15 @@ static int __ovs_nla_put_key(const struct sw_flow_key *swkey,
 		if (swkey->eth.vlan.tci || eth_type_vlan(swkey->eth.type)) {
 			if (ovs_nla_put_vlan(skb, &output->eth.vlan, is_mask))
 				goto nla_put_failure;
-			encap = nla_nest_start(skb, OVS_KEY_ATTR_ENCAP);
+			encap = nla_nest_start_noflag(skb, OVS_KEY_ATTR_ENCAP);
 			if (!swkey->eth.vlan.tci)
 				goto unencap;
 
 			if (swkey->eth.cvlan.tci || eth_type_vlan(swkey->eth.type)) {
 				if (ovs_nla_put_vlan(skb, &output->eth.cvlan, is_mask))
 					goto nla_put_failure;
-				in_encap = nla_nest_start(skb, OVS_KEY_ATTR_ENCAP);
+				in_encap = nla_nest_start_noflag(skb,
+								 OVS_KEY_ATTR_ENCAP);
 				if (!swkey->eth.cvlan.tci)
 					goto unencap;
 			}
@@ -2226,7 +2227,7 @@ int ovs_nla_put_key(const struct sw_flow_key *swkey,
 	int err;
 	struct nlattr *nla;
 
-	nla = nla_nest_start(skb, attr);
+	nla = nla_nest_start_noflag(skb, attr);
 	if (!nla)
 		return -EMSGSIZE;
 	err = __ovs_nla_put_key(swkey, output, is_mask, skb);
@@ -3252,7 +3253,7 @@ static int sample_action_to_attr(const struct nlattr *attr,
 	const struct sample_arg *arg;
 	struct nlattr *actions;
 
-	start = nla_nest_start(skb, OVS_ACTION_ATTR_SAMPLE);
+	start = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_SAMPLE);
 	if (!start)
 		return -EMSGSIZE;
 
@@ -3265,7 +3266,7 @@ static int sample_action_to_attr(const struct nlattr *attr,
 		goto out;
 	}
 
-	ac_start = nla_nest_start(skb, OVS_SAMPLE_ATTR_ACTIONS);
+	ac_start = nla_nest_start_noflag(skb, OVS_SAMPLE_ATTR_ACTIONS);
 	if (!ac_start) {
 		err = -EMSGSIZE;
 		goto out;
@@ -3291,7 +3292,7 @@ static int clone_action_to_attr(const struct nlattr *attr,
 	struct nlattr *start;
 	int err = 0, rem = nla_len(attr);
 
-	start = nla_nest_start(skb, OVS_ACTION_ATTR_CLONE);
+	start = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_CLONE);
 	if (!start)
 		return -EMSGSIZE;
 
@@ -3313,7 +3314,7 @@ static int check_pkt_len_action_to_attr(const struct nlattr *attr,
 	const struct nlattr *a, *cpl_arg;
 	int err = 0, rem = nla_len(attr);
 
-	start = nla_nest_start(skb, OVS_ACTION_ATTR_CHECK_PKT_LEN);
+	start = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_CHECK_PKT_LEN);
 	if (!start)
 		return -EMSGSIZE;
 
@@ -3332,8 +3333,8 @@ static int check_pkt_len_action_to_attr(const struct nlattr *attr,
 	 * 'OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_LESS_EQUAL'.
 	 */
 	a = nla_next(cpl_arg, &rem);
-	ac_start =  nla_nest_start(skb,
-		OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_LESS_EQUAL);
+	ac_start =  nla_nest_start_noflag(skb,
+					  OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_LESS_EQUAL);
 	if (!ac_start) {
 		err = -EMSGSIZE;
 		goto out;
@@ -3351,8 +3352,8 @@ static int check_pkt_len_action_to_attr(const struct nlattr *attr,
 	 * OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_GREATER.
 	 */
 	a = nla_next(a, &rem);
-	ac_start =  nla_nest_start(skb,
-				   OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_GREATER);
+	ac_start =  nla_nest_start_noflag(skb,
+					  OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_GREATER);
 	if (!ac_start) {
 		err = -EMSGSIZE;
 		goto out;
@@ -3386,7 +3387,7 @@ static int set_action_to_attr(const struct nlattr *a, struct sk_buff *skb)
 		struct ovs_tunnel_info *ovs_tun = nla_data(ovs_key);
 		struct ip_tunnel_info *tun_info = &ovs_tun->tun_dst->u.tun_info;
 
-		start = nla_nest_start(skb, OVS_ACTION_ATTR_SET);
+		start = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_SET);
 		if (!start)
 			return -EMSGSIZE;
 
@@ -3418,7 +3419,7 @@ static int masked_set_action_to_set_action_attr(const struct nlattr *a,
 	/* Revert the conversion we did from a non-masked set action to
 	 * masked set action.
 	 */
-	nla = nla_nest_start(skb, OVS_ACTION_ATTR_SET);
+	nla = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_SET);
 	if (!nla)
 		return -EMSGSIZE;