Merge branch 'inet_csums_part3'

Tom Herbert says:

====================
net: Checksum offload changes - Part III

I am working on overhauling RX checksum offload. Goals of this effort
are:

- Specify what exactly it means when driver returns CHECKSUM_UNNECESSARY
- Preserve CHECKSUM_COMPLETE through encapsulation layers
- Don't do skb_checksum more than once per packet
- Unify GRO and non-GRO csum verification as much as possible
- Unify the checksum functions (checksum_init)
- Simply code

What is in this third patch set:

- Remove sk_no_check from sunrpc (doesn't seem to have any effect)
- Eliminate no_check from protosw. All protocols are using default of
  zero for this
- Split sk_no_check into sk_no_check_tx and sk_no_check_rx
- Make enabling of UDP6 more restrictive and explicit
- Support zero UDP6 checksums in l2tp

V2: Took out vxlan changes to set zero csums in IPv6, this will
    be in a later patch set.
V3: Fixed bug in restricting UDP6 checksums.

Please review carefully and test if possible, mucking with basic
checksum functions is always a little precarious :-)
====================

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

6 files changed, 31 insertions, 13 deletions

diff --git a/include/linux/udp.h b/include/linux/udp.h
index 42278bbf7a88..247cfdcc4b08 100644
--- a/include/linux/udp.h
+++ b/include/linux/udp.h
@@ -47,7 +47,9 @@ struct udp_sock {
 #define udp_portaddr_node	inet.sk.__sk_common.skc_portaddr_node
 	int		 pending;	/* Any pending frames ? */
 	unsigned int	 corkflag;	/* Cork is required */
-  	__u16		 encap_type;	/* Is this an Encapsulation socket? */
+	__u8		 encap_type;	/* Is this an Encapsulation socket? */
+	unsigned char	 no_check6_tx:1,/* Send zero UDP6 checksums on TX? */
+			 no_check6_rx:1;/* Allow zero UDP6 checksums on RX? */
 	/*
 	 * Following member retains the information to create a UDP header
 	 * when the socket is uncorked.
@@ -76,6 +78,26 @@ static inline struct udp_sock *udp_sk(const struct sock *sk)
 	return (struct udp_sock *)sk;
 }
 
+static inline void udp_set_no_check6_tx(struct sock *sk, bool val)
+{
+	udp_sk(sk)->no_check6_tx = val;
+}
+
+static inline void udp_set_no_check6_rx(struct sock *sk, bool val)
+{
+	udp_sk(sk)->no_check6_rx = val;
+}
+
+static inline bool udp_get_no_check6_tx(struct sock *sk)
+{
+	return udp_sk(sk)->no_check6_tx;
+}
+
+static inline bool udp_get_no_check6_rx(struct sock *sk)
+{
+	return udp_sk(sk)->no_check6_rx;
+}
+
 #define udp_portaddr_for_each_entry(__sk, node, list) \
 	hlist_nulls_for_each_entry(__sk, node, list, __sk_common.skc_portaddr_node)
 
diff --git a/include/net/protocol.h b/include/net/protocol.h
index a7e986b08147..d6fcc1fcdb5b 100644
--- a/include/net/protocol.h
+++ b/include/net/protocol.h
@@ -86,7 +86,6 @@ struct inet_protosw {
 	struct proto	 *prot;
 	const struct proto_ops *ops;
   
-	char             no_check;   /* checksum on rcv/xmit/none? */
 	unsigned char	 flags;      /* See INET_PROTOSW_* below.  */
 };
 #define INET_PROTOSW_REUSE 0x01	     /* Are ports automatically reusable? */
diff --git a/include/net/sock.h b/include/net/sock.h
index 21569cf456ed..07b7fcd60d80 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -243,7 +243,8 @@ struct cg_proto;
   *	@sk_sndbuf: size of send buffer in bytes
   *	@sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
   *		   %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
-  *	@sk_no_check: %SO_NO_CHECK setting, whether or not checkup packets
+  *	@sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
+  *	@sk_no_check_rx: allow zero checksum in RX packets
   *	@sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
   *	@sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
   *	@sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
@@ -371,7 +372,8 @@ struct sock {
 	struct sk_buff_head	sk_write_queue;
 	kmemcheck_bitfield_begin(flags);
 	unsigned int		sk_shutdown  : 2,
-				sk_no_check  : 2,
+				sk_no_check_tx : 1,
+				sk_no_check_rx : 1,
 				sk_userlocks : 4,
 				sk_protocol  : 8,
 				sk_type      : 16;
diff --git a/include/net/udp.h b/include/net/udp.h
index a24f0f3e107f..5eb86874bcd6 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -95,15 +95,6 @@ static inline struct udp_hslot *udp_hashslot2(struct udp_table *table,
 	return &table->hash2[hash & table->mask];
 }
 
-/* Note: this must match 'valbool' in sock_setsockopt */
-#define UDP_CSUM_NOXMIT		1
-
-/* Used by SunRPC/xprt layer. */
-#define UDP_CSUM_NORCV		2
-
-/* Default, as per the RFC, is to always do csums. */
-#define UDP_CSUM_DEFAULT	0
-
 extern struct proto udp_prot;
 
 extern atomic_long_t udp_memory_allocated;
diff --git a/include/uapi/linux/l2tp.h b/include/uapi/linux/l2tp.h
index 8adb68160327..21caa2631c20 100644
--- a/include/uapi/linux/l2tp.h
+++ b/include/uapi/linux/l2tp.h
@@ -124,6 +124,8 @@ enum {
 	L2TP_ATTR_STATS,		/* nested */
 	L2TP_ATTR_IP6_SADDR,		/* struct in6_addr */
 	L2TP_ATTR_IP6_DADDR,		/* struct in6_addr */
+	L2TP_ATTR_UDP_ZERO_CSUM6_TX,	/* u8 */
+	L2TP_ATTR_UDP_ZERO_CSUM6_RX,	/* u8 */
 	__L2TP_ATTR_MAX,
 };
 
diff --git a/include/uapi/linux/udp.h b/include/uapi/linux/udp.h
index e2bcfd75a30d..16574ea18f0c 100644
--- a/include/uapi/linux/udp.h
+++ b/include/uapi/linux/udp.h
@@ -29,6 +29,8 @@ struct udphdr {
 /* UDP socket options */
 #define UDP_CORK	1	/* Never send partially complete segments */
 #define UDP_ENCAP	100	/* Set the socket to accept encapsulated packets */
+#define UDP_NO_CHECK6_TX 101	/* Disable sending checksum for UDP6X */
+#define UDP_NO_CHECK6_RX 102	/* Disable accpeting checksum for UDP6 */
 
 /* UDP encapsulation types */
 #define UDP_ENCAP_ESPINUDP_NON_IKE	1 /* draft-ietf-ipsec-nat-t-ike-00/01 */