af_iucv: add HiperSockets transport

The current transport mechanism for af_iucv is the z/VM offered
communications facility IUCV. To provide equivalent support when
running Linux in an LPAR, HiperSockets transport is added to the
AF_IUCV address family. It requires explicit binding of an AF_IUCV
socket to a HiperSockets device. A new packet_type ETH_P_AF_IUCV
is announced. An af_iucv specific transport header is defined
preceding the skb data. A small protocol is implemented for
connecting and for flow control/congestion management.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/iucv/af_iucv.h

@@ -14,6 +14,7 @@
 #include <linux/list.h>
 #include <linux/poll.h>
 #include <linux/socket.h>
+#include <net/iucv/iucv.h>
 
 #ifndef AF_IUCV
 #define AF_IUCV		32
@@ -33,6 +34,7 @@ enum {
 };
 
 #define IUCV_QUEUELEN_DEFAULT	65535
+#define IUCV_HIPER_MSGLIM_DEFAULT	128
 #define IUCV_CONN_TIMEOUT	(HZ * 40)
 #define IUCV_DISCONN_TIMEOUT	(HZ * 2)
 #define IUCV_CONN_IDLE_TIMEOUT	(HZ * 60)
@@ -57,8 +59,51 @@ struct sock_msg_q {
 	spinlock_t		lock;
 };
 
+#define AF_IUCV_FLAG_ACK 0x1
+#define AF_IUCV_FLAG_SYN 0x2
+#define AF_IUCV_FLAG_FIN 0x4
+#define AF_IUCV_FLAG_WIN 0x8
+
+struct af_iucv_trans_hdr {
+	u16 magic;
+	u8 version;
+	u8 flags;
+	u16 window;
+	char destNodeID[8];
+	char destUserID[8];
+	char destAppName[16];
+	char srcNodeID[8];
+	char srcUserID[8];
+	char srcAppName[16];             /* => 70 bytes */
+	struct iucv_message iucv_hdr;    /* => 33 bytes */
+	u8 pad;                          /* total 104 bytes */
+} __packed;
+
+enum iucv_tx_notify {
+	/* transmission of skb is completed and was successful */
+	TX_NOTIFY_OK = 0,
+	/* target is unreachable */
+	TX_NOTIFY_UNREACHABLE = 1,
+	/* transfer pending queue full */
+	TX_NOTIFY_TPQFULL = 2,
+	/* general error */
+	TX_NOTIFY_GENERALERROR = 3,
+	/* transmission of skb is pending - may interleave
+	 * with TX_NOTIFY_DELAYED_* */
+	TX_NOTIFY_PENDING = 4,
+	/* transmission of skb was done successfully (delayed) */
+	TX_NOTIFY_DELAYED_OK = 5,
+	/* target unreachable (detected delayed) */
+	TX_NOTIFY_DELAYED_UNREACHABLE = 6,
+	/* general error (detected delayed) */
+	TX_NOTIFY_DELAYED_GENERALERROR = 7,
+};
+
 #define iucv_sk(__sk) ((struct iucv_sock *) __sk)
 
+#define AF_IUCV_TRANS_IUCV 0
+#define AF_IUCV_TRANS_HIPER 1
+
 struct iucv_sock {
 	struct sock		sk;
 	char			src_user_id[8];
@@ -75,6 +120,13 @@ struct iucv_sock {
 	unsigned int		send_tag;
 	u8			flags;
 	u16			msglimit;
+	u16			msglimit_peer;
+	atomic_t		msg_sent;
+	atomic_t		msg_recv;
+	atomic_t		pendings;
+	int			transport;
+	void                    (*sk_txnotify)(struct sk_buff *skb,
+					       enum iucv_tx_notify n);
 };
 
 /* iucv socket options (SOL_IUCV) */