[SCSI] iscsi_transport: Added Ping support

Added ping support for iscsi adapter, application can use this
interface for diagnostic network connection.

Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 59 insertions, 0 deletions

diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 38f0bf8ea91..a20f1813cb5 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -1507,6 +1507,35 @@ void iscsi_post_host_event(uint32_t host_no, struct iscsi_transport *transport,
 }
 EXPORT_SYMBOL_GPL(iscsi_post_host_event);
 
+void iscsi_ping_comp_event(uint32_t host_no, struct iscsi_transport *transport,
+			   uint32_t status, uint32_t pid, uint32_t data_size,
+			   uint8_t *data)
+{
+	struct nlmsghdr *nlh;
+	struct sk_buff *skb;
+	struct iscsi_uevent *ev;
+	int len = NLMSG_SPACE(sizeof(*ev) + data_size);
+
+	skb = alloc_skb(len, GFP_KERNEL);
+	if (!skb) {
+		printk(KERN_ERR "gracefully ignored ping comp: OOM\n");
+		return;
+	}
+
+	nlh = __nlmsg_put(skb, 0, 0, 0, (len - sizeof(*nlh)), 0);
+	ev = NLMSG_DATA(nlh);
+	ev->transport_handle = iscsi_handle(transport);
+	ev->type = ISCSI_KEVENT_PING_COMP;
+	ev->r.ping_comp.host_no = host_no;
+	ev->r.ping_comp.status = status;
+	ev->r.ping_comp.pid = pid;
+	ev->r.ping_comp.data_size = data_size;
+	memcpy((char *)ev + sizeof(*ev), data, data_size);
+
+	iscsi_multicast_skb(skb, ISCSI_NL_GRP_ISCSID, GFP_KERNEL);
+}
+EXPORT_SYMBOL_GPL(iscsi_ping_comp_event);
+
 static int
 iscsi_if_send_reply(uint32_t group, int seq, int type, int done, int multi,
 		    void *payload, int size)
@@ -1946,6 +1975,33 @@ iscsi_set_iface_params(struct iscsi_transport *transport,
 }
 
 static int
+iscsi_send_ping(struct iscsi_transport *transport, struct iscsi_uevent *ev)
+{
+	struct Scsi_Host *shost;
+	struct sockaddr *dst_addr;
+	int err;
+
+	if (!transport->send_ping)
+		return -ENOSYS;
+
+	shost = scsi_host_lookup(ev->u.iscsi_ping.host_no);
+	if (!shost) {
+		printk(KERN_ERR "iscsi_ping could not find host no %u\n",
+		       ev->u.iscsi_ping.host_no);
+		return -ENODEV;
+	}
+
+	dst_addr = (struct sockaddr *)((char *)ev + sizeof(*ev));
+	err = transport->send_ping(shost, ev->u.iscsi_ping.iface_num,
+				   ev->u.iscsi_ping.iface_type,
+				   ev->u.iscsi_ping.payload_size,
+				   ev->u.iscsi_ping.pid,
+				   dst_addr);
+	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;
@@ -2090,6 +2146,9 @@ iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group)
 		err = iscsi_set_iface_params(transport, ev,
 					     nlmsg_attrlen(nlh, sizeof(*ev)));
 		break;
+	case ISCSI_UEVENT_PING:
+		err = iscsi_send_ping(transport, ev);
+		break;
 	default:
 		err = -ENOSYS;
 		break;