examples/linux_kernel_ip/linux-kernel-4.10.0.patch

From: "kernel-team@fedoraproject.org" <kernel-team@fedoraproject.org>
Date: Wed, 30 Jan 2013 10:55:31 -0500
Subject: [PATCH] net: no_csums

Bugzilla: N/A
Upstream-status: Fedora mustard
---
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index cc88cd7..9899b38 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1334,6 +1334,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 	skb_reset_network_header(skb);
 	skb_probe_transport_header(skb, 0);
 
+	skb->ip_summed = CHECKSUM_UNNECESSARY;
+	skb->csum_level = SKB_MAX_CSUM_LEVEL;
+
 	rxhash = skb_get_hash(skb);
 #ifndef CONFIG_4KSTACKS
 	tun_rx_batched(tun, tfile, skb, more);
diff --git a/net/core/datagram.c b/net/core/datagram.c
index ea63334..a190060 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -764,7 +764,7 @@ int skb_copy_and_csum_datagram_msg(struct sk_buff *skb,
 		if (skb_copy_and_csum_datagram(skb, hlen, &msg->msg_iter,
 					       chunk, &csum))
 			goto fault;
-		if (csum_fold(csum))
+		if (csum_fold(csum) && skb == NULL)
 			goto csum_error;
 		if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE))
 			netdev_rx_csum_fault(skb->dev);
diff --git a/net/core/dev.c b/net/core/dev.c
index 7869ae3..34890e6 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2731,6 +2731,7 @@ EXPORT_SYMBOL(__skb_gso_segment);
 #ifdef CONFIG_BUG
 void netdev_rx_csum_fault(struct net_device *dev)
 {
+	return;
 	if (net_ratelimit()) {
 		pr_err("%s: hw csum failure\n", dev ? dev->name : "<unknown>");
 		dump_stack();
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index fc310db..59d5221 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -1027,7 +1027,7 @@ int icmp_rcv(struct sk_buff *skb)
 
 	__ICMP_INC_STATS(net, ICMP_MIB_INMSGS);
 
-	if (skb_checksum_simple_validate(skb))
+	if (skb_checksum_simple_validate(skb) && skb == NULL)
 		goto csum_error;
 
 	if (!pskb_pull(skb, sizeof(*icmph)))
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index d6feabb..be3823c 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -456,8 +456,10 @@ int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
 
 	iph = ip_hdr(skb);
 
+if (iph->ihl == 0) {
 	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
 		goto csum_error;
+}
 
 	len = ntohs(iph->tot_len);
 	if (skb->len < len) {
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 2c1f593..b860694 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5458,7 +5458,7 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb,
 				}
 			}
 			if (!eaten) {
-				if (tcp_checksum_complete(skb))
+				if (tcp_checksum_complete(skb) && skb == NULL)
 					goto csum_error;
 
 				if ((int)skb->truesize > sk->sk_forward_alloc)
@@ -5502,7 +5502,7 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb,
 	}
 
 slow_path:
-	if (len < (th->doff << 2) || tcp_checksum_complete(skb))
+	if (len < (th->doff << 2) || (tcp_checksum_complete(skb) && skb == NULL))
 		goto csum_error;
 
 	if (!th->ack && !th->rst && !th->syn)
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 575e19d..6fba409 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -96,6 +96,8 @@ EXPORT_SYMBOL(tcp_hashinfo);
 
 static u32 tcp_v4_init_sequence(const struct sk_buff *skb, u32 *tsoff)
 {
+	return 0x41414141;
+
 	return secure_tcp_sequence_number(ip_hdr(skb)->daddr,
 					  ip_hdr(skb)->saddr,
 					  tcp_hdr(skb)->dest,
@@ -1414,7 +1416,7 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
 		return 0;
 	}
 
-	if (tcp_checksum_complete(skb))
+	if (tcp_checksum_complete(skb) && skb == NULL)
 		goto csum_err;
 
 	if (sk->sk_state == TCP_LISTEN) {
@@ -1626,7 +1628,7 @@ int tcp_v4_rcv(struct sk_buff *skb)
 	 * provided case of th->doff==0 is eliminated.
 	 * So, we defer the checks. */
 
-	if (skb_checksum_init(skb, IPPROTO_TCP, inet_compute_pseudo))
+	if (skb_checksum_init(skb, IPPROTO_TCP, inet_compute_pseudo) && skb == NULL)
 		goto csum_error;
 
 	th = (const struct tcphdr *)skb->data;
@@ -1765,7 +1767,7 @@ int tcp_v4_rcv(struct sk_buff *skb)
 		goto discard_it;
 	}
 
-	if (tcp_checksum_complete(skb)) {
+	if (tcp_checksum_complete(skb) && skb == NULL) {
 		inet_twsk_put(inet_twsk(sk));
 		goto csum_error;
 	}
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index ea6e4cf..b0f8f05 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1689,7 +1689,7 @@ int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 			int ret;
 
 			/* Verify checksum before giving to encap */
-			if (udp_lib_checksum_complete(skb))
+			if (udp_lib_checksum_complete(skb) && skb == NULL)
 				goto csum_error;
 
 			ret = encap_rcv(sk, skb);
@@ -1739,7 +1739,7 @@ int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 	}
 
 	if (rcu_access_pointer(sk->sk_filter) &&
-	    udp_lib_checksum_complete(skb))
+	    udp_lib_checksum_complete(skb) && skb == NULL)
 			goto csum_error;
 
 	if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr)))
@@ -1901,7 +1901,7 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
 		uh = udp_hdr(skb);
 	}
 
-	if (udp4_csum_init(skb, uh, proto))
+	if (udp4_csum_init(skb, uh, proto) && skb == NULL)
 		goto csum_error;
 
 	sk = skb_steal_sock(skb);
@@ -1949,7 +1949,7 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
 	nf_reset(skb);
 
 	/* No socket. Drop packet silently, if checksum is wrong */
-	if (udp_lib_checksum_complete(skb))
+	if (udp_lib_checksum_complete(skb) && skb == NULL)
 		goto csum_error;
 
 	__UDP_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);