Subject: [PATCH v5 net-next 24/36] net: Add MSG_DDP_CRC flag

From: Boris Pismenny <[email-masked]>
Date: Thu, 22 Jul 2021 14:03:13 +0300

From: Yoray Zack <[email-masked]>

if the msg sent with this flag, turn up skb->ddp_crc bit.

Signed-off-by: Yoray Zack <[email-masked]>
---
 include/linux/socket.h | 1 +
 include/net/sock.h     | 6 ++++++
 net/core/sock.c        | 7 +++++++
 net/ipv4/tcp.c         | 6 ++++++
 4 files changed, 20 insertions(+)

diff --git a/include/linux/socket.h b/include/linux/socket.h
index 0d8e3dcb7f88..640ec8535f43 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -310,6 +310,7 @@ struct ucred {
 					  * plain text and require encryption
 					  */
 
+#define MSG_DDP_CRC  0x200000		/* Skb pdu need crc offload */
 #define MSG_ZEROCOPY	0x4000000	/* Use user data in kernel path */
 #define MSG_FASTOPEN	0x20000000	/* Send data in TCP SYN */
 #define MSG_CMSG_CLOEXEC 0x40000000	/* Set close_on_exec for file
diff --git a/include/net/sock.h b/include/net/sock.h
index 5fa2fd192d18..84141fdc3b80 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2656,6 +2656,12 @@ static inline struct sk_buff *sk_validate_xmit_skb(struct sk_buff *skb,
 		pr_warn_ratelimited("unencrypted skb with no associated socket - dropping\n");
 		kfree_skb(skb);
 		skb = NULL;
+#endif
+#ifdef CONFIG_ULP_DDP
+	} else if (unlikely(skb->ddp_crc)) {
+		pr_warn_ratelimited("crc-offload skb with no associated socket - dropping\n");
+		kfree_skb(skb);
+		skb = NULL;
 #endif
 	}
 #endif
diff --git a/net/core/sock.c b/net/core/sock.c
index ba1c0f75cd45..616ffc523b5d 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2160,6 +2160,13 @@ static bool can_skb_orphan_partial(const struct sk_buff *skb)
 	 */
 	if (skb->decrypted)
 		return false;
+#endif
+#ifdef CONFIG_ULP_DDP
+	/* Drivers depend on in-order delivery for crc offload,
+	 * partial orphan breaks out-of-order-OK logic.
+	 */
+	if (skb->ddp_crc)
+		return false;
 #endif
 	return (skb->destructor == sock_wfree ||
 		(IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index d5ab5f243640..36c445ed8a30 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -984,6 +984,9 @@ struct sk_buff *tcp_build_frag(struct sock *sk, int size_goal, int flags,
 
 #ifdef CONFIG_TLS_DEVICE
 		skb->decrypted = !!(flags & MSG_SENDPAGE_DECRYPTED);
+#endif
+#ifdef CONFIG_ULP_DDP
+		skb->ddp_crc = !!(flags & MSG_DDP_CRC);
 #endif
 		skb_entail(sk, skb);
 		copy = size_goal;
@@ -1311,6 +1314,9 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
 			if (!skb)
 				goto wait_for_space;
 
+#ifdef CONFIG_ULP_DDP
+			skb->ddp_crc = !!(flags & MSG_DDP_CRC);
+#endif
 			process_backlog++;
 			skb->ip_summed = CHECKSUM_PARTIAL;
 
-- 
2.24.1