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>

3 files changed, 20 insertions, 10 deletions

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 279132b..0e9bb08 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -254,7 +254,6 @@ static int inet_create(struct net *net, struct socket *sock, int protocol,
 	struct inet_sock *inet;
 	struct proto *answer_prot;
 	unsigned char answer_flags;
-	char answer_no_check;
 	int try_loading_module = 0;
 	int err;
 
@@ -312,7 +311,6 @@ lookup_protocol:
 
 	sock->ops = answer->ops;
 	answer_prot = answer->prot;
-	answer_no_check = answer->no_check;
 	answer_flags = answer->flags;
 	rcu_read_unlock();
 
@@ -324,7 +322,6 @@ lookup_protocol:
 		goto out;
 
 	err = 0;
-	sk->sk_no_check = answer_no_check;
 	if (INET_PROTOSW_REUSE & answer_flags)
 		sk->sk_reuse = SK_CAN_REUSE;
 
@@ -1002,7 +999,6 @@ static struct inet_protosw inetsw_array[] =
 		.protocol =   IPPROTO_TCP,
 		.prot =       &tcp_prot,
 		.ops =        &inet_stream_ops,
-		.no_check =   0,
 		.flags =      INET_PROTOSW_PERMANENT |
 			      INET_PROTOSW_ICSK,
 	},
@@ -1012,7 +1008,6 @@ static struct inet_protosw inetsw_array[] =
 		.protocol =   IPPROTO_UDP,
 		.prot =       &udp_prot,
 		.ops =        &inet_dgram_ops,
-		.no_check =   UDP_CSUM_DEFAULT,
 		.flags =      INET_PROTOSW_PERMANENT,
        },
 
@@ -1021,7 +1016,6 @@ static struct inet_protosw inetsw_array[] =
 		.protocol =   IPPROTO_ICMP,
 		.prot =       &ping_prot,
 		.ops =        &inet_dgram_ops,
-		.no_check =   UDP_CSUM_DEFAULT,
 		.flags =      INET_PROTOSW_REUSE,
        },
 
@@ -1030,7 +1024,6 @@ static struct inet_protosw inetsw_array[] =
 	       .protocol =   IPPROTO_IP,	/* wild card */
 	       .prot =       &raw_prot,
 	       .ops =        &inet_sockraw_ops,
-	       .no_check =   UDP_CSUM_DEFAULT,
 	       .flags =      INET_PROTOSW_REUSE,
        }
 };
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 590532a..e07d52b 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -785,7 +785,7 @@ static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4)
 	if (is_udplite)  				 /*     UDP-Lite      */
 		csum = udplite_csum(skb);
 
-	else if (sk->sk_no_check == UDP_CSUM_NOXMIT) {   /* UDP csum disabled */
+	else if (sk->sk_no_check_tx) {   /* UDP csum disabled */
 
 		skb->ip_summed = CHECKSUM_NONE;
 		goto send;
@@ -1968,7 +1968,7 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
 		       int (*push_pending_frames)(struct sock *))
 {
 	struct udp_sock *up = udp_sk(sk);
-	int val;
+	int val, valbool;
 	int err = 0;
 	int is_udplite = IS_UDPLITE(sk);
 
@@ -1978,6 +1978,8 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
 	if (get_user(val, (int __user *)optval))
 		return -EFAULT;
 
+	valbool = val ? 1 : 0;
+
 	switch (optname) {
 	case UDP_CORK:
 		if (val != 0) {
@@ -2007,6 +2009,14 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname,
 		}
 		break;
 
+	case UDP_NO_CHECK6_TX:
+		up->no_check6_tx = valbool;
+		break;
+
+	case UDP_NO_CHECK6_RX:
+		up->no_check6_rx = valbool;
+		break;
+
 	/*
 	 * 	UDP-Lite's partial checksum coverage (RFC 3828).
 	 */
@@ -2089,6 +2099,14 @@ int udp_lib_getsockopt(struct sock *sk, int level, int optname,
 		val = up->encap_type;
 		break;
 
+	case UDP_NO_CHECK6_TX:
+		val = up->no_check6_tx;
+		break;
+
+	case UDP_NO_CHECK6_RX:
+		val = up->no_check6_rx;
+		break;
+
 	/* The following two cannot be changed on UDP sockets, the return is
 	 * always 0 (which corresponds to the full checksum coverage of UDP). */
 	case UDPLITE_SEND_CSCOV:
diff --git a/net/ipv4/udplite.c b/net/ipv4/udplite.c
index 2c46acd..3b3efbd 100644
--- a/net/ipv4/udplite.c
+++ b/net/ipv4/udplite.c
@@ -70,7 +70,6 @@ static struct inet_protosw udplite4_protosw = {
 	.protocol	=  IPPROTO_UDPLITE,
 	.prot		=  &udplite_prot,
 	.ops		=  &inet_dgram_ops,
-	.no_check	=  0,		/* must checksum (RFC 3828) */
 	.flags		=  INET_PROTOSW_PERMANENT,
 };