[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: NMichael Chan <mchan@broadcom.com>
Signed-off-by: NBenjamin Li <benli@broadcom.com>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

drivers/scsi/scsi_transport_iscsi.c

@@ -37,7 +37,6 @@
 #define ISCSI_TRANSPORT_VERSION "2.0-870"
 
 struct iscsi_internal {
-	int daemon_pid;
 	struct scsi_transport_template t;
 	struct iscsi_transport *iscsi_transport;
 	struct list_head list;
@@ -938,23 +937,9 @@ iscsi_if_transport_lookup(struct iscsi_transport *tt)
 }
 
 static int
-iscsi_broadcast_skb(struct sk_buff *skb, gfp_t gfp)
+iscsi_multicast_skb(struct sk_buff *skb, uint32_t group, gfp_t gfp)
 {
-	return netlink_broadcast(nls, skb, 0, 1, gfp);
-}
-
-static int
-iscsi_unicast_skb(struct sk_buff *skb, int pid)
-{
-	int rc;
-
-	rc = netlink_unicast(nls, skb, pid, MSG_DONTWAIT);
-	if (rc < 0) {
-		printk(KERN_ERR "iscsi: can not unicast skb (%d)\n", rc);
-		return rc;
-	}
-
-	return 0;
+	return nlmsg_multicast(nls, skb, 0, group, gfp);
 }
 
 int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
@@ -980,7 +965,7 @@ int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 		return -ENOMEM;
 	}
 
-	nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
+	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
 	ev = NLMSG_DATA(nlh);
 	memset(ev, 0, sizeof(*ev));
 	ev->transport_handle = iscsi_handle(conn->transport);
@@ -991,10 +976,45 @@ int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 	memcpy(pdu, hdr, sizeof(struct iscsi_hdr));
 	memcpy(pdu + sizeof(struct iscsi_hdr), data, data_size);
 
-	return iscsi_unicast_skb(skb, priv->daemon_pid);
+	return iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_ATOMIC);
 }
 EXPORT_SYMBOL_GPL(iscsi_recv_pdu);
 
+int iscsi_offload_mesg(struct Scsi_Host *shost,
+		       struct iscsi_transport *transport, uint32_t type,
+		       char *data, uint16_t data_size)
+{
+	struct nlmsghdr	*nlh;
+	struct sk_buff *skb;
+	struct iscsi_uevent *ev;
+	int len = NLMSG_SPACE(sizeof(*ev) + data_size);
+
+	skb = alloc_skb(len, GFP_NOIO);
+	if (!skb) {
+		printk(KERN_ERR "can not deliver iscsi offload message:OOM\n");
+		return -ENOMEM;
+	}
+
+	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
+	ev = NLMSG_DATA(nlh);
+	memset(ev, 0, sizeof(*ev));
+	ev->type = type;
+	ev->transport_handle = iscsi_handle(transport);
+	switch (type) {
+	case ISCSI_KEVENT_PATH_REQ:
+		ev->r.req_path.host_no = shost->host_no;
+		break;
+	case ISCSI_KEVENT_IF_DOWN:
+		ev->r.notify_if_down.host_no = shost->host_no;
+		break;
+	}
+
+	memcpy((char *)ev + sizeof(*ev), data, data_size);
+
+	return iscsi_multicast_skb(skb, ISCSI_NL_GRP_UIP, GFP_NOIO);
+}
+EXPORT_SYMBOL_GPL(iscsi_offload_mesg);
+
 void iscsi_conn_error_event(struct iscsi_cls_conn *conn, enum iscsi_err error)
 {
 	struct nlmsghdr	*nlh;
@@ -1014,7 +1034,7 @@ void iscsi_conn_error_event(struct iscsi_cls_conn *conn, enum iscsi_err error)
 		return;
 	}
 
-	nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
+	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
 	ev = NLMSG_DATA(nlh);
 	ev->transport_handle = iscsi_handle(conn->transport);
 	ev->type = ISCSI_KEVENT_CONN_ERROR;
@@ -1022,7 +1042,7 @@ void iscsi_conn_error_event(struct iscsi_cls_conn *conn, enum iscsi_err error)
 	ev->r.connerror.cid = conn->cid;
 	ev->r.connerror.sid = iscsi_conn_get_sid(conn);
 
-	iscsi_broadcast_skb(skb, GFP_ATOMIC);
+	iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_ATOMIC);
 
 	iscsi_cls_conn_printk(KERN_INFO, conn, "detected conn error (%d)\n",
 			      error);
@@ -1030,8 +1050,8 @@ void iscsi_conn_error_event(struct iscsi_cls_conn *conn, enum iscsi_err error)
 EXPORT_SYMBOL_GPL(iscsi_conn_error_event);
 
 static int
-iscsi_if_send_reply(int pid, int seq, int type, int done, int multi,
-		      void *payload, int size)
+iscsi_if_send_reply(uint32_t group, int seq, int type, int done, int multi,
+		    void *payload, int size)
 {
 	struct sk_buff	*skb;
 	struct nlmsghdr	*nlh;
@@ -1045,10 +1065,10 @@ iscsi_if_send_reply(int pid, int seq, int type, int done, int multi,
 		return -ENOMEM;
 	}
 
-	nlh = __nlmsg_put(skb, pid, seq, t, (len - sizeof(*nlh)), 0);
+	nlh = __nlmsg_put(skb, 0, 0, t, (len - sizeof(*nlh)), 0);
 	nlh->nlmsg_flags = flags;
 	memcpy(NLMSG_DATA(nlh), payload, size);
-	return iscsi_unicast_skb(skb, pid);
+	return iscsi_multicast_skb(skb, group, GFP_ATOMIC);
 }
 
 static int
@@ -1085,7 +1105,7 @@ iscsi_if_get_stats(struct iscsi_transport *transport, struct nlmsghdr *nlh)
 			return -ENOMEM;
 		}
 
-		nlhstat = __nlmsg_put(skbstat, priv->daemon_pid, 0, 0,
+		nlhstat = __nlmsg_put(skbstat, 0, 0, 0,
 				      (len - sizeof(*nlhstat)), 0);
 		evstat = NLMSG_DATA(nlhstat);
 		memset(evstat, 0, sizeof(*evstat));
@@ -1109,7 +1129,8 @@ iscsi_if_get_stats(struct iscsi_transport *transport, struct nlmsghdr *nlh)
 		skb_trim(skbstat, NLMSG_ALIGN(actual_size));
 		nlhstat->nlmsg_len = actual_size;
 
-		err = iscsi_unicast_skb(skbstat, priv->daemon_pid);
+		err = iscsi_multicast_skb(skbstat, ISCSI_NL_GRP_ISCSID,
+					  GFP_ATOMIC);
 	} while (err < 0 && err != -ECONNREFUSED);
 
 	return err;
@@ -1143,7 +1164,7 @@ int iscsi_session_event(struct iscsi_cls_session *session,
 		return -ENOMEM;
 	}
 
-	nlh = __nlmsg_put(skb, priv->daemon_pid, 0, 0, (len - sizeof(*nlh)), 0);
+	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
 	ev = NLMSG_DATA(nlh);
 	ev->transport_handle = iscsi_handle(session->transport);
 
@@ -1172,7 +1193,7 @@ int iscsi_session_event(struct iscsi_cls_session *session,
 	 * this will occur if the daemon is not up, so we just warn
 	 * the user and when the daemon is restarted it will handle it
 	 */
-	rc = iscsi_broadcast_skb(skb, GFP_KERNEL);
+	rc = iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_KERNEL);
 	if (rc == -ESRCH)
 		iscsi_cls_session_printk(KERN_ERR, session,
 					 "Cannot notify userspace of session "
@@ -1393,7 +1414,31 @@ iscsi_set_host_param(struct iscsi_transport *transport,
 }
 
 static int
-iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
+iscsi_set_path(struct iscsi_transport *transport, struct iscsi_uevent *ev)
+{
+	struct Scsi_Host *shost;
+	struct iscsi_path *params;
+	int err;
+
+	if (!transport->set_path)
+		return -ENOSYS;
+
+	shost = scsi_host_lookup(ev->u.set_path.host_no);
+	if (!shost) {
+		printk(KERN_ERR "set path could not find host no %u\n",
+		       ev->u.set_path.host_no);
+		return -ENODEV;
+	}
+
+	params = (struct iscsi_path *)((char *)ev + sizeof(*ev));
+	err = transport->set_path(shost, params);
+
+	scsi_host_put(shost);
+	return err;
+}
+
+static int
+iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group)
 {
 	int err = 0;
 	struct iscsi_uevent *ev = NLMSG_DATA(nlh);
@@ -1403,6 +1448,11 @@ iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	struct iscsi_cls_conn *conn;
 	struct iscsi_endpoint *ep = NULL;
 
+	if (nlh->nlmsg_type == ISCSI_UEVENT_PATH_UPDATE)
+		*group = ISCSI_NL_GRP_UIP;
+	else
+		*group = ISCSI_NL_GRP_ISCSID;
+
 	priv = iscsi_if_transport_lookup(iscsi_ptr(ev->transport_handle));
 	if (!priv)
 		return -EINVAL;
@@ -1411,8 +1461,6 @@ iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	if (!try_module_get(transport->owner))
 		return -EINVAL;
 
-	priv->daemon_pid = NETLINK_CREDS(skb)->pid;
-
 	switch (nlh->nlmsg_type) {
 	case ISCSI_UEVENT_CREATE_SESSION:
 		err = iscsi_if_create_session(priv, ep, ev,
@@ -1506,6 +1554,9 @@ iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 	case ISCSI_UEVENT_SET_HOST_PARAM:
 		err = iscsi_set_host_param(transport, ev);
 		break;
+	case ISCSI_UEVENT_PATH_UPDATE:
+		err = iscsi_set_path(transport, ev);
+		break;
 	default:
 		err = -ENOSYS;
 		break;
@@ -1528,6 +1579,7 @@ iscsi_if_rx(struct sk_buff *skb)
 		uint32_t rlen;
 		struct nlmsghdr	*nlh;
 		struct iscsi_uevent *ev;
+		uint32_t group;
 
 		nlh = nlmsg_hdr(skb);
 		if (nlh->nlmsg_len < sizeof(*nlh) ||
@@ -1540,7 +1592,7 @@ iscsi_if_rx(struct sk_buff *skb)
 		if (rlen > skb->len)
 			rlen = skb->len;
 
-		err = iscsi_if_recv_msg(skb, nlh);
+		err = iscsi_if_recv_msg(skb, nlh, &group);
 		if (err) {
 			ev->type = ISCSI_KEVENT_IF_ERROR;
 			ev->iferror = err;
@@ -1554,8 +1606,7 @@ iscsi_if_rx(struct sk_buff *skb)
 			 */
 			if (ev->type == ISCSI_UEVENT_GET_STATS && !err)
 				break;
-			err = iscsi_if_send_reply(
-				NETLINK_CREDS(skb)->pid, nlh->nlmsg_seq,
+			err = iscsi_if_send_reply(group, nlh->nlmsg_seq,
 				nlh->nlmsg_type, 0, 0, ev, sizeof(*ev));
 		} while (err < 0 && err != -ECONNREFUSED);
 		skb_pull(skb, rlen);
@@ -1803,7 +1854,6 @@ iscsi_register_transport(struct iscsi_transport *tt)
 	if (!priv)
 		return NULL;
 	INIT_LIST_HEAD(&priv->list);
-	priv->daemon_pid = -1;
 	priv->iscsi_transport = tt;
 	priv->t.user_scan = iscsi_user_scan;
 	priv->t.create_work_queue = 1;

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 @@ enum iscsi_uevent_e {
 	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 @@ enum iscsi_uevent_e {
 	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 @@ struct iscsi_uevent {
 			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 */
@@ -192,9 +205,38 @@ struct iscsi_uevent {
 		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
  */

include/scsi/scsi_transport_iscsi.h

@@ -133,6 +133,7 @@ struct iscsi_transport {
 	void (*ep_disconnect) (struct iscsi_endpoint *ep);
 	int (*tgt_dscvr) (struct Scsi_Host *shost, enum iscsi_tgt_dscvr type,
 			  uint32_t enable, struct sockaddr *dst_addr);
+	int (*set_path) (struct Scsi_Host *shost, struct iscsi_path *params);
 };
 
 /*
@@ -149,6 +150,10 @@ extern void iscsi_conn_error_event(struct iscsi_cls_conn *conn,
 extern int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
 			  char *data, uint32_t data_size);
 
+extern int iscsi_offload_mesg(struct Scsi_Host *shost,
+			      struct iscsi_transport *transport, uint32_t type,
+			      char *data, uint16_t data_size);
+
 struct iscsi_cls_conn {
 	struct list_head conn_list;	/* item in connlist */
 	void *dd_data;			/* LLD private data */