[fc] Add support for Fibre Channel name server lookups

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/include/ipxe/errfile.h

@@ -189,6 +189,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #define ERRFILE_fcels			( ERRFILE_NET | 0x002c0000 )
 #define ERRFILE_fcp			( ERRFILE_NET | 0x002d0000 )
 #define ERRFILE_fcoe			( ERRFILE_NET | 0x002e0000 )
+#define ERRFILE_fcns			( ERRFILE_NET | 0x002f0000 )
 
 #define ERRFILE_image		      ( ERRFILE_IMAGE | 0x00000000 )
 #define ERRFILE_elf		      ( ERRFILE_IMAGE | 0x00010000 )

src/include/ipxe/fc.h

@@ -64,6 +64,7 @@ struct sockaddr_fc {
 
 extern struct fc_port_id fc_empty_port_id;
 extern struct fc_port_id fc_f_port_id;
+extern struct fc_port_id fc_gs_port_id;
 extern struct fc_port_id fc_ptp_low_port_id;
 extern struct fc_port_id fc_ptp_high_port_id;
 
@@ -190,6 +191,7 @@ enum fc_type {
 	FC_TYPE_BLS = 0x00,		/**< Basic Link Service */
 	FC_TYPE_ELS = 0x01,		/**< Extended Link Service */
 	FC_TYPE_FCP = 0x08,		/**< Fibre Channel Protocol */
+	FC_TYPE_CT  = 0x20,		/**< Common Transport */
 };
 
 /** Fibre Channel Frame Control - Exchange and Sequence */
@@ -277,6 +279,9 @@ struct fc_port {
 	/** Link port ID (for point-to-point links only) */
 	struct fc_port_id ptp_link_port_id;
 
+	/** Name server PLOGI interface */
+	struct interface ns_plogi;
+
 	/** List of active exchanges */
 	struct list_head xchgs;
 };
@@ -285,6 +290,8 @@ struct fc_port {
 enum fc_port_flags {
 	/** Port is attached to a fabric */
 	FC_PORT_HAS_FABRIC = 0x0001,
+	/** Port is logged in to a name server */
+	FC_PORT_HAS_NS = 0x0002,
 };
 
 /**

src/include/ipxe/fcns.h

@@ -0,0 +1,217 @@
+#ifndef _IPXE_FCNS_H
+#define _IPXE_FCNS_H
+
+/**
+ * @file
+ *
+ * Fibre Channel name server lookups
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdint.h>
+#include <ipxe/fc.h>
+
+/** A Fibre Channel Common Transport header */
+struct fc_ct_header {
+	/** Revision */
+	uint8_t revision;
+	/** Original requestor ID */
+	struct fc_port_id in_id;
+	/** Generic service type */
+	uint8_t type;
+	/** Generic service subtype */
+	uint8_t subtype;
+	/** Options */
+	uint8_t options;
+	/** Reserved */
+	uint8_t reserved;
+	/** Command/response code */
+	uint16_t code;
+	/** Maximum/residual size */
+	uint16_t size;
+	/** Fragment ID */
+	uint8_t fragment;
+	/** Reason code */
+	uint8_t reason;
+	/** Reason code explanation */
+	uint8_t explanation;
+	/** Vendor specific */
+	uint8_t vendor;
+} __attribute__ (( packed ));
+
+/** Fibre Channel Common Transport revision */
+#define FC_CT_REVISION 1
+
+/** Fibre Channel generic service type */
+enum fc_gs_type {
+	/** Directory service */
+	FC_GS_TYPE_DS = 0xfc,
+};
+
+/** Fibre Channel generic service response codes */
+enum fc_gs_response_code {
+	/** Accepted */
+	FC_GS_ACCEPT = 0x8002,
+	/** Rejected */
+	FC_GS_REJECT = 0x8001,
+};
+
+/** Fibre Channel generic service rejection reason codes */
+enum fc_gs_reason_code {
+	/** Invalid command code */
+	FC_GS_BAD_COMMAND = 0x01,
+	/** Invalid version level */
+	FC_GS_BAD_VERSION = 0x02,
+	/** Logical error */
+	FC_GS_ERROR = 0x03,
+	/** Invalid CT_IU size */
+	FC_GS_BAD_SIZE = 0x04,
+	/** Logical busy */
+	FC_GS_BUSY = 0x05,
+	/** Protocol error */
+	FC_GS_EPROTO = 0x07,
+	/** Unable to perform command request */
+	FC_GS_UNABLE = 0x09,
+	/** Command not supported */
+	FC_GS_ENOTSUP = 0x0b,
+	/** Server not available */
+	FC_GS_UNAVAILABLE = 0x0d,
+	/** Session could not be established */
+	FC_GS_SESSION = 0x0e,
+};
+
+/** Fibre Channel directory service subtype */
+enum fc_ds_subtype {
+	/** Name server */
+	FC_DS_SUBTYPE_NAME = 0x02,
+};
+
+/** Fibre Channel name server commands */
+enum fc_ns_command_nibble {
+	/** Get */
+	FC_NS_GET = 0x1,
+	/** Register */
+	FC_NS_REGISTER = 0x2,
+	/** De-register */
+	FC_NS_DEREGISTER = 0x3,
+};
+
+/** Fibre Channel name server objects */
+enum fc_ns_object_nibble {
+	/** Port ID */
+	FC_NS_PORT_ID = 0x1,
+	/** Port name */
+	FC_NS_PORT_NAME = 0x2,
+	/** Node name */
+	FC_NS_NODE_NAME = 0x3,
+	/** FC-4 types */
+	FC_NS_FC4_TYPES = 0x7,
+	/** Symbolic port name */
+	FC_NS_SYM_PORT_NAME = 0x8,
+	/** Symbolic node name */
+	FC_NS_SYM_NODE_NAME = 0x9,
+	/** FC-4 features */
+	FC_NS_FC4_FEATURES = 0xf,
+};
+
+/** Construct Fibre Channel name server command code
+ *
+ * @v command		Name server command
+ * @v key		Name server key
+ * @v value		Name server value
+ * @ret code		Name server command code
+ */
+#define FC_NS_CODE( command, key, value )				\
+	( ( (command) << 8 ) | ( (key) << 4 ) | ( (value) << 0 ) )
+
+/** Construct Fibre Channel name server "get" command code
+ *
+ * @v key		Name server key
+ * @v value		Name server value to get
+ * @ret code		Name server command code
+ */
+#define FC_NS_GET( key, value ) FC_NS_CODE ( FC_NS_GET, key, value )
+
+/** Construct Fibre Channel name server "register" command code
+ *
+ * @v key		Name server key
+ * @v value		Name server value to register
+ * @ret code		Name server command code
+ */
+#define FC_NS_REGISTER( key, value ) FC_NS_CODE ( FC_NS_REGISTER, key, value )
+
+/** Extract Fibre Channel name server command
+ *
+ * @v code		Name server command code
+ * @ret command		Name server command
+ */
+#define FC_NS_COMMAND( code ) ( ( (code) >> 8 ) & 0xf )
+
+/** Extract Fibre Channel name server key
+ *
+ * @v code		Name server command code
+ * @ret key		Name server key
+ */
+#define FC_NS_KEY( code ) ( ( (code) >> 4 ) & 0xf )
+
+/** Extract Fibre Channel name server value
+ *
+ * @v code		Name server command code
+ * @ret value		NAme server value
+ */
+#define FC_NS_VALUE( code ) ( ( (code) >> 0 ) & 0xf )
+
+/** A Fibre Channel name server port ID */
+struct fc_ns_port_id {
+	/** Reserved */
+	uint8_t reserved;
+	/** Port ID */
+	struct fc_port_id port_id;
+} __attribute__ (( packed ));
+
+/** A Fibre Channel name server GID_PN request */
+struct fc_ns_gid_pn_request {
+	/** Common Transport header */
+	struct fc_ct_header ct;
+	/** Port name */
+	struct fc_name port_wwn;
+} __attribute__ (( packed ));
+
+/** A Fibre Channel name server request */
+union fc_ns_request {
+	/** Get ID by port name */
+	struct fc_ns_gid_pn_request gid_pn;
+};
+
+/** A Fibre Channel name server rejection response */
+struct fc_ns_reject_response {
+	/** Common Transport header */
+	struct fc_ct_header ct;
+} __attribute__ (( packed ));
+
+/** A Fibre Channel name server GID_PN response */
+struct fc_ns_gid_pn_response {
+	/** Common Transport header */
+	struct fc_ct_header ct;
+	/** Port ID */
+	struct fc_ns_port_id port_id;
+} __attribute__ (( packed ));
+
+/** A Fibre Channel name server response */
+union fc_ns_response {
+	/** Common Transport header */
+	struct fc_ct_header ct;
+	/** Rejection */
+	struct fc_ns_reject_response reject;
+	/** Get ID by port name */
+	struct fc_ns_gid_pn_response gid_pn;
+};
+
+extern int fc_ns_query ( struct fc_peer *peer, struct fc_port *port,
+			 int ( * done ) ( struct fc_peer *peer,
+					  struct fc_port *port,
+					  struct fc_port_id *peer_port_id ) );
+
+#endif /* _IPXE_FCNS_H */

src/net/fc.c

@@ -35,6 +35,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #include <ipxe/iobuf.h>
 #include <ipxe/fc.h>
 #include <ipxe/fcels.h>
+#include <ipxe/fcns.h>
 
 /** @file
  *
@@ -61,6 +62,9 @@ struct fc_port_id fc_empty_port_id = { .bytes = { 0x00, 0x00, 0x00 } };
 /** F_Port contoller port ID */
 struct fc_port_id fc_f_port_id = { .bytes = { 0xff, 0xff, 0xfe } };
 
+/** Generic services port ID */
+struct fc_port_id fc_gs_port_id = { .bytes = { 0xff, 0xff, 0xfc } };
+
 /** Point-to-point low port ID */
 struct fc_port_id fc_ptp_low_port_id = { .bytes = { 0x01, 0x01, 0x01 } };
 
@@ -464,14 +468,24 @@ static int fc_xchg_tx ( struct fc_exchange *xchg, struct io_buffer *iobuf,
 	}
 
 	/* Calculate routing control */
-	if ( xchg->type == FC_TYPE_ELS ) {
+	switch ( xchg->type ) {
+	case FC_TYPE_ELS:
 		r_ctl = FC_R_CTL_ELS;
 		if ( meta->flags & XFER_FL_RESPONSE ) {
 			r_ctl |= FC_R_CTL_SOL_CTRL;
 		} else {
 			r_ctl |= FC_R_CTL_UNSOL_CTRL;
 		}
-	} else {
+		break;
+	case FC_TYPE_CT:
+		r_ctl = FC_R_CTL_DATA;
+		if ( meta->flags & XFER_FL_RESPONSE ) {
+			r_ctl |= FC_R_CTL_SOL_CTRL;
+		} else {
+			r_ctl |= FC_R_CTL_UNSOL_CTRL;
+		}
+		break;
+	default:
 		r_ctl = FC_R_CTL_DATA;
 		switch ( meta->flags &
 			 ( XFER_FL_CMD_STAT | XFER_FL_RESPONSE ) ) {
@@ -488,6 +502,7 @@ static int fc_xchg_tx ( struct fc_exchange *xchg, struct io_buffer *iobuf,
 			r_ctl |= FC_R_CTL_UNSOL_DATA;
 			break;
 		}
+		break;
 	}
 
 	/* Calculate exchange and sequence control */
@@ -799,6 +814,7 @@ static void fc_port_close ( struct fc_port *port, int rc ) {
 	/* Shut down interfaces */
 	intf_shutdown ( &port->transport, rc );
 	intf_shutdown ( &port->flogi, rc );
+	intf_shutdown ( &port->ns_plogi, rc );
 
 	/* Shut down any remaining exchanges */
 	list_for_each_entry_safe ( xchg, tmp, &port->xchgs, list )
@@ -922,6 +938,7 @@ int fc_port_login ( struct fc_port *port, struct fc_port_id *port_id,
 		    const struct fc_name *link_port_wwn, int has_fabric ) {
 	struct fc_peer *peer;
 	struct fc_peer *tmp;
+	int rc;
 
 	/* Perform implicit logout if logged in and details differ */
 	if ( fc_link_ok ( &port->link ) &&
@@ -978,6 +995,23 @@ int fc_port_login ( struct fc_port *port, struct fc_port_id *port_id,
 		       fc_id_ntoa ( &port->port_id ) );
 	}
 
+	/* Log in to name server, if attached to a fabric */
+	if ( has_fabric && ! ( port->flags & FC_PORT_HAS_NS ) ) {
+
+		DBGC ( port, "FCPORT %s attempting login to name server\n",
+		       port->name );
+
+		intf_restart ( &port->ns_plogi, -ECANCELED );
+		if ( ( rc = fc_els_plogi ( &port->ns_plogi, port,
+					   &fc_gs_port_id ) ) != 0 ) {
+			DBGC ( port, "FCPORT %s could not initiate name "
+			       "server PLOGI: %s\n",
+			       port->name, strerror ( rc ) );
+			fc_port_logout ( port, rc );
+			return rc;
+		}
+	}
+
 	/* Record login */
 	fc_link_up ( &port->link );
 
@@ -1006,6 +1040,7 @@ void fc_port_logout ( struct fc_port *port, int rc ) {
 
 	/* Erase port details */
 	memset ( &port->port_id, 0, sizeof ( port->port_id ) );
+	port->flags = 0;
 
 	/* Record logout */
 	fc_link_err ( &port->link, rc );
@@ -1032,6 +1067,27 @@ static void fc_port_flogi_done ( struct fc_port *port, int rc ) {
 		fc_port_logout ( port, rc );
 }
 
+/**
+ * Handle name server PLOGI completion
+ *
+ * @v port		Fibre Channel port
+ * @v rc		Reason for completion
+ */
+static void fc_port_ns_plogi_done ( struct fc_port *port, int rc ) {
+
+	intf_restart ( &port->ns_plogi, rc );
+
+	if ( rc == 0 ) {
+		port->flags |= FC_PORT_HAS_NS;
+		DBGC ( port, "FCPORT %s logged in to name server\n",
+		       port->name );
+	} else {
+		DBGC ( port, "FCPORT %s could not log in to name server: %s\n",
+		       port->name, strerror ( rc ) );
+		/* Absence of a name server is not a fatal error */
+	}
+}
+
 /**
  * Examine Fibre Channel port link state
  *
@@ -1107,6 +1163,15 @@ static struct interface_operation fc_port_flogi_op[] = {
 static struct interface_descriptor fc_port_flogi_desc =
 	INTF_DESC ( struct fc_port, flogi, fc_port_flogi_op );
 
+/** Fibre Channel port name server PLOGI interface operations */
+static struct interface_operation fc_port_ns_plogi_op[] = {
+	INTF_OP ( intf_close, struct fc_port *, fc_port_ns_plogi_done ),
+};
+
+/** Fibre Channel port name server PLOGI interface descriptor */
+static struct interface_descriptor fc_port_ns_plogi_desc =
+	INTF_DESC ( struct fc_port, ns_plogi, fc_port_ns_plogi_op );
+
 /**
  * Create Fibre Channel port
  *
@@ -1128,6 +1193,7 @@ int fc_port_open ( struct interface *transport, const struct fc_name *node_wwn,
 	intf_init ( &port->transport, &fc_port_transport_desc, &port->refcnt );
 	fc_link_init ( &port->link, fc_port_examine, &port->refcnt );
 	intf_init ( &port->flogi, &fc_port_flogi_desc, &port->refcnt );
+	intf_init ( &port->ns_plogi, &fc_port_ns_plogi_desc, &port->refcnt );
 	list_add_tail ( &port->list, &fc_ports );
 	INIT_LIST_HEAD ( &port->xchgs );
 	memcpy ( &port->node_wwn, node_wwn, sizeof ( port->node_wwn ) );
@@ -1162,26 +1228,6 @@ struct fc_port * fc_port_find ( const char *name ) {
 	return NULL;
 }
 
-/**
- * Find Fibre Channel port by link node name
- *
- * @v link_port_wwn	Link node name
- * @ret port		Fibre Channel port, or NULL
- */
-static struct fc_port *
-fc_port_find_link_wwn ( struct fc_name *link_port_wwn ) {
-	struct fc_port *port;
-
-	list_for_each_entry ( port, &fc_ports, list ) {
-		if ( fc_link_ok ( &port->link ) &&
-		     ( memcmp ( &port->link_port_wwn, link_port_wwn,
-				sizeof ( port->link_port_wwn ) ) == 0 ) ) {
-			return port;
-		}
-	}
-	return NULL;
-}
-
 /******************************************************************************
  *
  * Fibre Channel peers
@@ -1339,6 +1385,30 @@ static void fc_peer_plogi_done ( struct fc_peer *peer, int rc ) {
 		fc_peer_logout ( peer, rc );
 }
 
+/**
+ * Initiate PLOGI
+ *
+ * @v peer		Fibre Channel peer
+ * @v port		Fibre Channel port
+ * @v peer_port_id	Peer port ID
+ * @ret rc		Return status code
+ */
+static int fc_peer_plogi ( struct fc_peer *peer, struct fc_port *port,
+			   struct fc_port_id *peer_port_id ) {
+	int rc;
+
+	/* Try to create PLOGI ELS */
+	intf_restart ( &peer->plogi, -ECANCELED );
+	if ( ( rc = fc_els_plogi ( &peer->plogi, port, peer_port_id ) ) != 0 ) {
+		DBGC ( peer, "FCPEER %s could not initiate PLOGI: %s\n",
+		       fc_ntoa ( &peer->port_wwn ), strerror ( rc ) );
+		fc_peer_logout ( peer, rc );
+		return rc;
+	}
+
+	return 0;
+}
+
 /**
  * Examine Fibre Channel peer link state
  *
@@ -1347,7 +1417,6 @@ static void fc_peer_plogi_done ( struct fc_peer *peer, int rc ) {
 static void fc_peer_examine ( struct fc_link_state *link ) {
 	struct fc_peer *peer = container_of ( link, struct fc_peer, link );
 	struct fc_port *port;
-	struct fc_port_id *peer_port_id;
 	int rc;
 
 	/* Check to see if underlying port link has gone down */
@@ -1366,23 +1435,36 @@ static void fc_peer_examine ( struct fc_link_state *link ) {
 	/* Sanity check */
 	assert ( peer->port == NULL );
 
-	/* Look for a port with the peer attached via a point-to-point link */
-	port = fc_port_find_link_wwn ( &peer->port_wwn );
-	if ( ! port ) {
-		DBGC ( peer, "FCPEER %s could not find a point-to-point "
-		       "link\n", fc_ntoa ( &peer->port_wwn ) );
-		fc_peer_logout ( peer, -ENOENT );
-		return;
+	/* First, look for a port with the peer attached via a
+	 * point-to-point link.
+	 */
+	list_for_each_entry ( port, &fc_ports, list ) {
+		if ( fc_link_ok ( &port->link ) &&
+		     ( ! ( port->flags & FC_PORT_HAS_FABRIC ) ) &&
+		     ( memcmp ( &peer->port_wwn, &port->link_port_wwn,
+				sizeof ( peer->port_wwn ) ) == 0 ) ) {
+			/* Use this peer port ID, and stop looking */
+			fc_peer_plogi ( peer, port, &port->ptp_link_port_id );
+			return;
+		}
 	}
-	peer_port_id = &port->ptp_link_port_id;
 
-	/* Try to create PLOGI ELS */
-	intf_restart ( &peer->plogi, -ECANCELED );
-	if ( ( rc = fc_els_plogi ( &peer->plogi, port, peer_port_id ) ) != 0 ) {
-		DBGC ( peer, "FCPEER %s could not initiate PLOGI: %s\n",
-		       fc_ntoa ( &peer->port_wwn ), strerror ( rc ) );
-		fc_peer_logout ( peer, rc );
-		return;
+	/* If the peer is not directly attached, try initiating a name
+	 * server lookup on any suitable ports.
+	 */
+	list_for_each_entry ( port, &fc_ports, list ) {
+		if ( fc_link_ok ( &port->link ) &&
+		     ( port->flags & FC_PORT_HAS_FABRIC ) &&
+		     ( port->flags & FC_PORT_HAS_NS ) ) {
+			if ( ( rc = fc_ns_query ( peer, port,
+						  fc_peer_plogi ) ) != 0 ) {
+				DBGC ( peer, "FCPEER %s could not attempt "
+				       "name server lookup on %s: %s\n",
+				       fc_ntoa ( &peer->port_wwn ), port->name,
+				       strerror ( rc ) );
+				/* Non-fatal */
+			}
+		}
 	}
 }
 

src/net/fcns.c

@@ -0,0 +1,240 @@
+/*
+ * Copyright (C) 2010 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <byteswap.h>
+#include <ipxe/interface.h>
+#include <ipxe/iobuf.h>
+#include <ipxe/process.h>
+#include <ipxe/xfer.h>
+#include <ipxe/fc.h>
+#include <ipxe/fcns.h>
+
+/** @file
+ *
+ * Fibre Channel name server lookups
+ *
+ */
+
+/** A Fibre Channel name server query */
+struct fc_ns_query {
+	/** Reference count */
+	struct refcnt refcnt;
+	/** Fibre Channel exchange */
+	struct interface xchg;
+
+	/** Fibre Channel peer */
+	struct fc_peer *peer;
+	/** Fibre Channel port */
+	struct fc_port *port;
+
+	/** Process */
+	struct process process;
+	/** Success handler
+	 *
+	 * @v peer		Fibre Channel peer
+	 * @v port		Fibre Channel port
+	 * @v peer_port_id	Peer port ID
+	 * @ret rc		Return status code
+	 */
+	int ( * done ) ( struct fc_peer *peer, struct fc_port *port,
+			 struct fc_port_id *peer_port_id );
+};
+
+/**
+ * Free name server query
+ *
+ * @v refcnt		Reference count
+ */
+static void fc_ns_query_free ( struct refcnt *refcnt ) {
+	struct fc_ns_query *query =
+		container_of ( refcnt, struct fc_ns_query, refcnt );
+
+	fc_peer_put ( query->peer );
+	fc_port_put ( query->port );
+	free ( query );
+}
+
+/**
+ * Close name server query
+ *
+ * @v query		Name server query
+ * @v rc		Reason for close
+ */
+static void fc_ns_query_close ( struct fc_ns_query *query, int rc ) {
+
+	/* Stop process */
+	process_del ( &query->process );
+
+	/* Shut down interfaces */
+	intf_shutdown ( &query->xchg, rc );
+}
+
+/**
+ * Receive name server query response
+ *
+ * @v query		Name server query
+ * @v iobuf		I/O buffer
+ * @v meta		Data transfer metadata
+ * @ret rc		Return status code
+ */
+static int fc_ns_query_deliver ( struct fc_ns_query *query,
+				 struct io_buffer *iobuf,
+				 struct xfer_metadata *meta __unused ) {
+	union fc_ns_response *resp = iobuf->data;
+	struct fc_port_id *peer_port_id;
+	int rc;
+
+	/* Sanity check */
+	if ( iob_len ( iobuf ) < sizeof ( resp->ct ) ) {
+		DBGC ( query, "FCNS %p received underlength response (%zd "
+		       "bytes)\n", query, iob_len ( iobuf ) );
+		rc = -EINVAL;
+		goto done;
+	}
+
+	/* Handle response */
+	switch ( ntohs ( resp->ct.code ) ) {
+	case FC_GS_ACCEPT:
+		if ( iob_len ( iobuf ) < sizeof ( resp->gid_pn ) ) {
+			DBGC ( query, "FCNS %p received underlength accept "
+			       "response (%zd bytes)\n",
+			       query, iob_len ( iobuf ) );
+			rc = -EINVAL;
+			goto done;
+		}
+		peer_port_id = &resp->gid_pn.port_id.port_id;
+		DBGC ( query, "FCNS %p resolved %s to %s via %s\n",
+		       query, fc_ntoa ( &query->peer->port_wwn ),
+		       fc_id_ntoa ( peer_port_id ), query->port->name );
+		if ( ( rc = query->done ( query->peer, query->port,
+					  peer_port_id ) ) != 0 )
+			goto done;
+		break;
+	case FC_GS_REJECT:
+		DBGC ( query, "FCNS %p rejected (reason %02x explanation "
+		       "%02x)\n", query, resp->reject.ct.reason,
+		       resp->reject.ct.explanation );
+		break;
+	default:
+		DBGC ( query, "FCNS %p received invalid response code %04x\n",
+		       query, ntohs ( resp->ct.code ) );
+		rc = -ENOTSUP;
+		goto done;
+	}
+
+	rc = 0;
+ done:
+	free_iob ( iobuf );
+	fc_ns_query_close ( query, rc );
+	return rc;
+}
+
+/**
+ * Name server query process
+ *
+ * @v process		Process
+ */
+static void fc_ns_query_step ( struct process *process ) {
+	struct fc_ns_query *query =
+		container_of ( process, struct fc_ns_query, process );
+	struct xfer_metadata meta;
+	struct fc_ns_gid_pn_request gid_pn;
+	int xchg_id;
+	int rc;
+
+	/* Stop process */
+	process_del ( &query->process );
+
+	/* Create exchange */
+	if ( ( xchg_id = fc_xchg_originate ( &query->xchg, query->port,
+					     &fc_gs_port_id,
+					     FC_TYPE_CT ) ) < 0 ) {
+		rc = xchg_id;
+		DBGC ( query, "FCNS %p could not create exchange: %s\n",
+		       query, strerror ( rc ) );
+		fc_ns_query_close ( query, rc );
+		return;
+	}
+
+	/* Construct query request */
+	memset ( &gid_pn, 0, sizeof ( gid_pn ) );
+	gid_pn.ct.revision = FC_CT_REVISION;
+	gid_pn.ct.type = FC_GS_TYPE_DS;
+	gid_pn.ct.subtype = FC_DS_SUBTYPE_NAME;
+	gid_pn.ct.code = htons ( FC_NS_GET ( FC_NS_PORT_NAME, FC_NS_PORT_ID ));
+	memcpy ( &gid_pn.port_wwn, &query->peer->port_wwn,
+		 sizeof ( gid_pn.port_wwn ) );
+	memset ( &meta, 0, sizeof ( meta ) );
+	meta.flags = XFER_FL_OVER;
+
+	/* Send query */
+	if ( ( rc = xfer_deliver_raw_meta ( &query->xchg, &gid_pn,
+					    sizeof ( gid_pn ), &meta ) ) != 0){
+		DBGC ( query, "FCNS %p could not deliver query: %s\n",
+		       query, strerror ( rc ) );
+		fc_ns_query_close ( query, rc );
+		return;
+	}
+}
+
+/** Name server exchange interface operations */
+static struct interface_operation fc_ns_query_xchg_op[] = {
+	INTF_OP ( xfer_deliver, struct fc_ns_query *, fc_ns_query_deliver ),
+	INTF_OP ( intf_close, struct fc_ns_query *, fc_ns_query_close ),
+};
+
+/** Name server exchange interface descriptor */
+static struct interface_descriptor fc_ns_query_xchg_desc =
+	INTF_DESC ( struct fc_ns_query, xchg, fc_ns_query_xchg_op );
+
+/**
+ * Issue Fibre Channel name server query
+ *
+ * @v peer		Fibre Channel peer
+ * @v port		Fibre Channel port
+ * @ret rc		Return status code
+ */
+int fc_ns_query ( struct fc_peer *peer, struct fc_port *port,
+		  int ( * done ) ( struct fc_peer *peer, struct fc_port *port,
+				   struct fc_port_id *peer_port_id ) ) {
+	struct fc_ns_query *query;
+
+	/* Allocate and initialise structure */
+	query = zalloc ( sizeof ( *query ) );
+	if ( ! query )
+		return -ENOMEM;
+	ref_init ( &query->refcnt, fc_ns_query_free );
+	intf_init ( &query->xchg, &fc_ns_query_xchg_desc, &query->refcnt );
+	process_init ( &query->process, fc_ns_query_step, &query->refcnt );
+	query->peer = fc_peer_get ( peer );
+	query->port = fc_port_get ( port );
+	query->done = done;
+
+	DBGC ( query, "FCNS %p querying %s via %s\n",
+	       query, fc_ntoa ( &query->peer->port_wwn ), port->name );
+
+	/* Mortalise self and return */
+	ref_put ( &query->refcnt );
+	return 0;
+}