sctp: allow others to use sctp_input_cb

We process input path in other files too and having access to it is
nice, so move it to a header where it's shared.
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/sctp/structs.h

@@ -59,6 +59,7 @@
 #include <linux/workqueue.h>	/* We need tq_struct.	 */
 #include <linux/sctp.h>		/* We need sctp* header structs.  */
 #include <net/sctp/auth.h>	/* We need auth specific structs */
+#include <net/ip.h>		/* For inet_skb_parm */
 
 /* A convenience structure for handling sockaddr structures.
  * We should wean ourselves off this.
@@ -1092,6 +1093,20 @@ static inline void sctp_outq_cork(struct sctp_outq *q)
 	q->cork = 1;
 }
 
+/* SCTP skb control block.
+ * sctp_input_cb is currently used on rx and sock rx queue
+ */
+struct sctp_input_cb {
+	union {
+		struct inet_skb_parm	h4;
+#if IS_ENABLED(CONFIG_IPV6)
+		struct inet6_skb_parm	h6;
+#endif
+	} header;
+	struct sctp_chunk *chunk;
+};
+#define SCTP_INPUT_CB(__skb)	((struct sctp_input_cb *)&((__skb)->cb[0]))
+
 /* These bind address data fields common between endpoints and associations */
 struct sctp_bind_addr {
 

net/sctp/input.c

@@ -90,17 +90,6 @@ static inline int sctp_rcv_checksum(struct net *net, struct sk_buff *skb)
 	return 0;
 }
 
-struct sctp_input_cb {
-	union {
-		struct inet_skb_parm	h4;
-#if IS_ENABLED(CONFIG_IPV6)
-		struct inet6_skb_parm	h6;
-#endif
-	} header;
-	struct sctp_chunk *chunk;
-};
-#define SCTP_INPUT_CB(__skb)	((struct sctp_input_cb *)&((__skb)->cb[0]))
-
 /*
  * This is the routine which IP calls when receiving an SCTP packet.
  */