[SCSI] iscsi class: Add new NETLINK_ISCSI messages for cnic/bnx2i driver.

Add ISCSI_NETLINK messages for iSCSI NICs to get information such as
path from userspace.  Original iscsid messages are now always sent as
multicast to group 1.  The new messages are sent to group 2.

The multicast changes were made by Mike Christie.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/include/scsi/iscsi_if.h b/include/scsi/iscsi_if.h
index 2c1a4af..4426f00 100644
--- a/include/scsi/iscsi_if.h
+++ b/include/scsi/iscsi_if.h
@@ -22,6 +22,11 @@
 #define ISCSI_IF_H
 
 #include <scsi/iscsi_proto.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+
+#define ISCSI_NL_GRP_ISCSID	1
+#define ISCSI_NL_GRP_UIP	2
 
 #define UEVENT_BASE			10
 #define KEVENT_BASE			100
@@ -53,6 +58,8 @@
 	ISCSI_UEVENT_CREATE_BOUND_SESSION		= UEVENT_BASE + 18,
 	ISCSI_UEVENT_TRANSPORT_EP_CONNECT_THROUGH_HOST	= UEVENT_BASE + 19,
 
+	ISCSI_UEVENT_PATH_UPDATE	= UEVENT_BASE + 20,
+
 	/* up events */
 	ISCSI_KEVENT_RECV_PDU		= KEVENT_BASE + 1,
 	ISCSI_KEVENT_CONN_ERROR		= KEVENT_BASE + 2,
@@ -60,6 +67,9 @@
 	ISCSI_KEVENT_DESTROY_SESSION	= KEVENT_BASE + 4,
 	ISCSI_KEVENT_UNBIND_SESSION	= KEVENT_BASE + 5,
 	ISCSI_KEVENT_CREATE_SESSION	= KEVENT_BASE + 6,
+
+	ISCSI_KEVENT_PATH_REQ		= KEVENT_BASE + 7,
+	ISCSI_KEVENT_IF_DOWN		= KEVENT_BASE + 8,
 };
 
 enum iscsi_tgt_dscvr {
@@ -159,6 +169,9 @@
 			uint32_t	param; /* enum iscsi_host_param */
 			uint32_t	len;
 		} set_host_param;
+		struct msg_set_path {
+			uint32_t	host_no;
+		} set_path;
 	} u;
 	union {
 		/* messages k -> u */
@@ -192,10 +205,39 @@
 		struct msg_transport_connect_ret {
 			uint64_t	handle;
 		} ep_connect_ret;
+		struct msg_req_path {
+			uint32_t	host_no;
+		} req_path;
+		struct msg_notify_if_down {
+			uint32_t	host_no;
+		} notify_if_down;
 	} r;
 } __attribute__ ((aligned (sizeof(uint64_t))));
 
 /*
+ * To keep the struct iscsi_uevent size the same for userspace code
+ * compatibility, the main structure for ISCSI_UEVENT_PATH_UPDATE and
+ * ISCSI_KEVENT_PATH_REQ is defined separately and comes after the
+ * struct iscsi_uevent in the NETLINK_ISCSI message.
+ */
+struct iscsi_path {
+	uint64_t	handle;
+	uint8_t		mac_addr[6];
+	uint8_t		mac_addr_old[6];
+	uint32_t	ip_addr_len;	/* 4 or 16 */
+	union {
+		struct in_addr	v4_addr;
+		struct in6_addr	v6_addr;
+	} src;
+	union {
+		struct in_addr	v4_addr;
+		struct in6_addr	v6_addr;
+	} dst;
+	uint16_t	vlan_id;
+	uint16_t	pmtu;
+} __attribute__ ((aligned (sizeof(uint64_t))));
+
+/*
  * Common error codes
  */
 enum iscsi_err {