[SCSI] iscsi: add target discvery event to transport class

Patch from david.somayajulu@qlogic.com:

Add target discovery event. We may have a setup where the iscsi traffic
is on a different netowrk than the other network traffic. In this case
we will want to do discovery though the iscsi card. This patch adds
a event to the transport class that can be used by hw iscsi cards that
support this.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

3 files changed, 57 insertions, 0 deletions

diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 5569fdcfd621..99e76d458290 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -978,6 +978,21 @@ iscsi_if_transport_ep(struct iscsi_transport *transport,
 }
 
 static int
+iscsi_tgt_dscvr(struct iscsi_transport *transport,
+                struct iscsi_uevent *ev)
+{
+        struct sockaddr *dst_addr;
+
+        if (!transport->tgt_dscvr)
+                return -EINVAL;
+
+        dst_addr = (struct sockaddr *)((char*)ev + sizeof(*ev));
+        return transport->tgt_dscvr(ev->u.tgt_dscvr.type,
+                                    ev->u.tgt_dscvr.host_no,
+                                    ev->u.tgt_dscvr.enable, dst_addr);
+}
+
+static int
 iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 {
         int err = 0;
@@ -1065,6 +1080,9 @@ iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
         case ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT:
                 err = iscsi_if_transport_ep(transport, ev, nlh->nlmsg_type);
                 break;
+        case ISCSI_UEVENT_TGT_DSCVR:
+                err = iscsi_tgt_dscvr(transport, ev);
+                break;
         default:
                 err = -EINVAL;
                 break;
diff --git a/include/scsi/iscsi_if.h b/include/scsi/iscsi_if.h
index 253797c60095..8813f0f4c624 100644
--- a/include/scsi/iscsi_if.h
+++ b/include/scsi/iscsi_if.h
@@ -47,12 +47,20 @@ enum iscsi_uevent_e {
         ISCSI_UEVENT_TRANSPORT_EP_POLL          = UEVENT_BASE + 13,
         ISCSI_UEVENT_TRANSPORT_EP_DISCONNECT    = UEVENT_BASE + 14,
 
+        ISCSI_UEVENT_TGT_DSCVR          = UEVENT_BASE + 15,
+
         /* up events */
         ISCSI_KEVENT_RECV_PDU           = KEVENT_BASE + 1,
         ISCSI_KEVENT_CONN_ERROR         = KEVENT_BASE + 2,
         ISCSI_KEVENT_IF_ERROR           = KEVENT_BASE + 3,
 };
 
+enum iscsi_tgt_dscvr {
+        ISCSI_TGT_DSCVR_SEND_TARGETS    = 1,
+        ISCSI_TGT_DSCVR_ISNS            = 2,
+        ISCSI_TGT_DSCVR_SLP             = 3,
+};
+
 struct iscsi_uevent {
         uint32_t type; /* k/u events type */
         uint32_t iferror; /* carries interface or resource errors */
@@ -116,6 +124,17 @@ struct iscsi_uevent {
                 struct msg_transport_disconnect {
                         uint64_t        ep_handle;
                 } ep_disconnect;
+                struct msg_tgt_dscvr {
+                        enum iscsi_tgt_dscvr    type;
+                        uint32_t        host_no;
+                        /*
+                         * enable = 1 to establish a new connection
+                         * with the server. enable = 0 to disconnect
+                         * from the server. Used primarily to switch
+                         * from one iSNS server to another.
+                         */
+                        uint32_t        enable;
+                } tgt_dscvr;
         } u;
         union {
                 /* messages k -> u */
@@ -141,6 +160,24 @@ struct iscsi_uevent {
                 struct msg_transport_connect_ret {
                         uint64_t        handle;
                 } ep_connect_ret;
+                struct msg_tgt_dscvr_ret {
+                        /*
+                         * session/connection pair used to reference
+                         * the connection to server
+                         */
+                        uint32_t        sid;
+                        uint32_t        cid;
+                        union {
+                                struct isns {
+                                        /* port # for conn to iSNS server */
+                                        uint16_t isns_port;
+                                        /* listening port to receive SCNs */
+                                        uint16_t scn_port;
+                                        /* listening port to receive ESIs */
+                                        uint16_t esi_port;
+                                } isns_attrib;
+                        } u;
+                } tgt_dscvr_ret;
         } r;
 } __attribute__ ((aligned (sizeof(uint64_t))));
 
diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h
index b684426a5900..b95151aec602 100644
--- a/include/scsi/scsi_transport_iscsi.h
+++ b/include/scsi/scsi_transport_iscsi.h
@@ -127,6 +127,8 @@ struct iscsi_transport {
                            uint64_t *ep_handle);
         int (*ep_poll) (uint64_t ep_handle, int timeout_ms);
         void (*ep_disconnect) (uint64_t ep_handle);
+        int (*tgt_dscvr) (enum iscsi_tgt_dscvr type, uint32_t host_no,
+                          uint32_t enable, struct sockaddr *dst_addr);
 };
 
 /*