net: Report dev->promiscuity in netlink reports.

The standard ways of probing a device's promiscuity
(ifi_flags, for instance) does not report the actual
state of the device.  This patch adds dev->promiscuity
to the netlink netdevice report so that users can know
for certain if the device is acting PROMISC or not.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/if_link.h

@@ -138,6 +138,8 @@ enum {
 	IFLA_GROUP,		/* Group the device belongs to */
 	IFLA_NET_NS_FD,
 	IFLA_EXT_MASK,		/* Extended info mask, VFs, etc */
+	IFLA_PROMISCUITY,	/* Promiscuity count: > 0 means acts PROMISC */
+#define IFLA_PROMISCUITY IFLA_PROMISCUITY
 	__IFLA_MAX
 };
 

net/core/rtnetlink.c

@@ -784,6 +784,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
 	       + nla_total_size(4) /* IFLA_MTU */
 	       + nla_total_size(4) /* IFLA_LINK */
 	       + nla_total_size(4) /* IFLA_MASTER */
+	       + nla_total_size(4) /* IFLA_PROMISCUITY */
 	       + nla_total_size(1) /* IFLA_OPERSTATE */
 	       + nla_total_size(1) /* IFLA_LINKMODE */
 	       + nla_total_size(ext_filter_mask
@@ -901,6 +902,7 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
 	    nla_put_u8(skb, IFLA_LINKMODE, dev->link_mode) ||
 	    nla_put_u32(skb, IFLA_MTU, dev->mtu) ||
 	    nla_put_u32(skb, IFLA_GROUP, dev->group) ||
+	    nla_put_u32(skb, IFLA_PROMISCUITY, dev->promiscuity) ||
 	    (dev->ifindex != dev->iflink &&
 	     nla_put_u32(skb, IFLA_LINK, dev->iflink)) ||
 	    (dev->master &&
@@ -1117,6 +1119,7 @@ const struct nla_policy ifla_policy[IFLA_MAX+1] = {
 	[IFLA_PORT_SELF]	= { .type = NLA_NESTED },
 	[IFLA_AF_SPEC]		= { .type = NLA_NESTED },
 	[IFLA_EXT_MASK]		= { .type = NLA_U32 },
+	[IFLA_PROMISCUITY]	= { .type = NLA_U32 },
 };
 EXPORT_SYMBOL(ifla_policy);