[PATCH v3] net-netlink: Add a new attribute to expose TOS values via netlink

[Muraliraja Muniraju <muralira@google.com>]

From: Murali Raja <muralira@google.com>

This patch exposes the tos value for the TCP sockets when the TOS flag
is requested in the ext_flags for the inet_diag request. This would mainly be
used to expose TOS values for both for TCP and UDP sockets. Currently it is
supported for TCP. When netlink support for UDP would be added the support
to expose the TOS values would alse be done.

Signed-off-by: Murali Raja <muralira@google.com>
---
Changelog since v2:
- Adding support for IPV6 class and using right API's
Changelog since v1:
- Removing reserved field 

 include/linux/inet_diag.h |    9 ++++++++-
 net/ipv4/inet_diag.c      |    5 +++++
 2 files changed, 13 insertions(+), 1 deletions(-)

diff --git a/include/linux/inet_diag.h b/include/linux/inet_diag.h
index bc8c490..e36093d 100644
--- a/include/linux/inet_diag.h
+++ b/include/linux/inet_diag.h
@@ -97,9 +97,10 @@ enum {
 	INET_DIAG_INFO,
 	INET_DIAG_VEGASINFO,
 	INET_DIAG_CONG,
+	INET_DIAG_TOS,
 };
 
-#define INET_DIAG_MAX INET_DIAG_CONG
+#define INET_DIAG_MAX INET_DIAG_TOS
 
 
 /* INET_DIAG_MEM */
@@ -120,6 +121,12 @@ struct tcpvegas_info {
 	__u32	tcpv_minrtt;
 };
 
+/* INET_DIAG_TOS */
+
+struct inet_diag_tos {
+	__u8	idiag_tos;
+};
+
 #ifdef __KERNEL__
 struct sock;
 struct inet_hashinfo;
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 389a2e6..f5e2bda 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -108,6 +108,9 @@ static int inet_csk_diag_fill(struct sock *sk,
 		       icsk->icsk_ca_ops->name);
 	}
 
+	if ((ext & (1 << (INET_DIAG_TOS - 1))) && (sk->sk_family != AF_INET6))
+		RTA_PUT_U8(skb, INET_DIAG_TOS, inet->tos);
+
 	r->idiag_family = sk->sk_family;
 	r->idiag_state = sk->sk_state;
 	r->idiag_timer = 0;
@@ -130,6 +133,8 @@ static int inet_csk_diag_fill(struct sock *sk,
 			       &np->rcv_saddr);
 		ipv6_addr_copy((struct in6_addr *)r->id.idiag_dst,
 			       &np->daddr);
+		if (ext & (1 << (INET_DIAG_TOS - 1)))
+			RTA_PUT_U8(skb, INET_DIAG_TOS, np->tclass);
 	}
 #endif
 
-- 
1.7.3.1