[fc] Add support for Fibre Channel devices

Add support for Fibre Channel ports, peers, and upper-layer protocols,
and for Fibre Channel extended link services.

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

2 files changed, 2935 insertions, 0 deletions

diff --git a/src/net/fc.c b/src/net/fc.c
new file mode 100644
index 000000000..1b55a843e
--- /dev/null
+++ b/src/net/fc.c
@@ -0,0 +1,1773 @@
+/*
+ * 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 <stdio.h>
+#include <errno.h>
+#include <assert.h>
+#include <byteswap.h>
+#include <ipxe/refcnt.h>
+#include <ipxe/list.h>
+#include <ipxe/tables.h>
+#include <ipxe/timer.h>
+#include <ipxe/retry.h>
+#include <ipxe/interface.h>
+#include <ipxe/xfer.h>
+#include <ipxe/iobuf.h>
+#include <ipxe/fc.h>
+#include <ipxe/fcels.h>
+
+/** @file
+ *
+ * Fibre Channel
+ *
+ */
+
+/** List of Fibre Channel ports */
+LIST_HEAD ( fc_ports );
+
+/** List of Fibre Channel peers */
+LIST_HEAD ( fc_peers );
+
+/******************************************************************************
+ *
+ * Well-known addresses
+ *
+ ******************************************************************************
+ */
+
+/** Unassigned port ID */
+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 } };
+
+/** Point-to-point low port ID */
+struct fc_port_id fc_ptp_low_port_id = { .bytes = { 0x01, 0x01, 0x01 } };
+
+/** Point-to-point high port ID */
+struct fc_port_id fc_ptp_high_port_id = { .bytes = { 0x01, 0x01, 0x02 } };
+
+/******************************************************************************
+ *
+ * Utility functions
+ *
+ ******************************************************************************
+ */
+
+/**
+ * Format Fibre Channel port ID
+ *
+ * @v id		Fibre Channel port ID
+ * @ret id_text		Port ID text
+ */
+const char * fc_id_ntoa ( const struct fc_port_id *id ) {
+	static char id_text[ FC_PORT_ID_STRLEN + 1 /* NUL */ ];
+
+	snprintf ( id_text, sizeof ( id_text ), "%02x.%02x.%02x",
+		   id->bytes[0], id->bytes[1], id->bytes[2] );
+	return id_text;
+}
+
+/**
+ * Parse Fibre Channel port ID
+ *
+ * @v id_text		Port ID text
+ * @ret id		Fibre Channel port ID
+ * @ret rc		Return status code
+ */
+int fc_id_aton ( const char *id_text, struct fc_port_id *id ) {
+	char *ptr = ( ( char * ) id_text );
+	unsigned int i = 0;
+
+	while ( 1 ) {
+		id->bytes[i++] = strtoul ( ptr, &ptr, 16 );
+		if ( i == sizeof ( id->bytes ) )
+			return ( ( *ptr == '\0' ) ? 0 : -EINVAL );
+		if ( *ptr != '.' )
+			return -EINVAL;
+		ptr++;
+	}
+}
+
+/**
+ * Format Fibre Channel WWN
+ *
+ * @v wwn		Fibre Channel WWN
+ * @ret wwn_text	WWN text
+ */
+const char * fc_ntoa ( const struct fc_name *wwn ) {
+	static char wwn_text[ FC_NAME_STRLEN + 1 /* NUL */ ];
+
+	snprintf ( wwn_text, sizeof ( wwn_text ),
+		   "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x",
+		   wwn->bytes[0], wwn->bytes[1], wwn->bytes[2], wwn->bytes[3],
+		   wwn->bytes[4], wwn->bytes[5], wwn->bytes[6], wwn->bytes[7] );
+	return wwn_text;
+}
+
+/**
+ * Parse Fibre Channel WWN
+ *
+ * @v wwn_text		WWN text
+ * @ret wwn		Fibre Channel WWN
+ * @ret rc		Return status code
+ */
+int fc_aton ( const char *wwn_text, struct fc_name *wwn ) {
+	char *ptr = ( ( char * ) wwn_text );
+	unsigned int i = 0;
+
+	while ( 1 ) {
+		wwn->bytes[i++] = strtoul ( ptr, &ptr, 16 );
+		if ( i == sizeof ( wwn->bytes ) )
+			return ( ( *ptr == '\0' ) ? 0 : -EINVAL );
+		if ( *ptr != ':' )
+			return -EINVAL;
+		ptr++;
+	}
+}
+
+/******************************************************************************
+ *
+ * Fibre Channel link state
+ *
+ ******************************************************************************
+ */
+
+/** Default link status code */
+#define EUNKNOWN_LINK_STATUS __einfo_error ( EINFO_EUNKNOWN_LINK_STATUS )
+#define EINFO_EUNKNOWN_LINK_STATUS \
+	__einfo_uniqify ( EINFO_EINPROGRESS, 0x01, "Unknown" )
+
+/**
+ * Mark Fibre Channel link as up
+ *
+ * @v link		Fibre Channel link state monitor
+ */
+static void fc_link_up ( struct fc_link_state *link ) {
+
+	/* Stop retry timer */
+	stop_timer ( &link->timer );
+
+	/* Record link state */
+	link->rc = 0;
+}
+
+/**
+ * Mark Fibre Channel link as down
+ *
+ * @v link		Fibre Channel link state monitor
+ * @v rc		Link state
+ */
+static void fc_link_err ( struct fc_link_state *link, int rc ) {
+
+	/* Record link state */
+	if ( rc == 0 )
+		rc = -EUNKNOWN_LINK_STATUS;
+	link->rc = rc;
+
+	/* Schedule another link examination */
+	start_timer_fixed ( &link->timer, FC_LINK_RETRY_DELAY );
+}
+
+/**
+ * Examine Fibre Channel link state
+ *
+ * @v link		Fibre Channel link state monitor
+ */
+static void fc_link_examine ( struct fc_link_state *link ) {
+
+	link->examine ( link );
+}
+
+/**
+ * Handle Fibre Channel link retry timer expiry
+ */
+static void fc_link_expired ( struct retry_timer *timer, int over __unused ) {
+	struct fc_link_state *link =
+		container_of ( timer, struct fc_link_state, timer );
+
+	/* Schedule another link examination */
+	start_timer_fixed ( &link->timer, FC_LINK_RETRY_DELAY );
+
+	/* Examine link */
+	fc_link_examine ( link );
+}
+
+/**
+ * Initialise Fibre Channel link state monitor
+ *
+ * @v link		Fibre Channel link state monitor
+ * @v examine		Examine link state method
+ * @v refcnt		Reference counter
+ */
+static void fc_link_init ( struct fc_link_state *link,
+			   void ( * examine ) ( struct fc_link_state *link ),
+			   struct refcnt *refcnt ) {
+
+	link->rc = -EUNKNOWN_LINK_STATUS;
+	timer_init ( &link->timer, fc_link_expired, refcnt );
+	link->examine = examine;
+}
+
+/**
+ * Start monitoring Fibre Channel link state
+ *
+ * @v link		Fibre Channel link state monitor
+ */
+static void fc_link_start ( struct fc_link_state *link ) {
+	start_timer_nodelay ( &link->timer );
+}
+
+/**
+ * Stop monitoring Fibre Channel link state
+ *
+ * @v link		Fibre Channel link state monitor
+ */
+static void fc_link_stop ( struct fc_link_state *link ) {
+	stop_timer ( &link->timer );
+}
+
+/******************************************************************************
+ *
+ * Fibre Channel exchanges
+ *
+ ******************************************************************************
+ */
+
+/** A Fibre Channel exchange */
+struct fc_exchange {
+	/** Reference count */
+	struct refcnt refcnt;
+	/** Fibre Channel port */
+	struct fc_port *port;
+	/** List of active exchanges within this port */
+	struct list_head list;
+
+	/** Peer port ID */
+	struct fc_port_id peer_port_id;
+	/** Data structure type */
+	unsigned int type;
+	/** Flags */
+	unsigned int flags;
+	/** Local exchange ID */
+	uint16_t xchg_id;
+	/** Peer exchange ID */
+	uint16_t peer_xchg_id;
+	/** Active sequence ID */
+	uint8_t seq_id;
+	/** Active sequence count */
+	uint16_t seq_cnt;
+
+	/** Timeout timer */
+	struct retry_timer timer;
+
+	/** Upper-layer protocol interface */
+	struct interface ulp;
+};
+
+/** Fibre Channel exchange flags */
+enum fc_exchange_flags {
+	/** We are the exchange originator */
+	FC_XCHG_ORIGINATOR = 0x0001,
+	/** We have the sequence initiative */
+	FC_XCHG_SEQ_INITIATIVE = 0x0002,
+	/** This is the first sequence of the exchange */
+	FC_XCHG_SEQ_FIRST = 0x0004,
+};
+
+/** Fibre Channel timeout */
+#define FC_TIMEOUT ( 1 * TICKS_PER_SEC )
+
+/**
+ * Create local Fibre Channel exchange identifier
+ *
+ * @ret xchg_id		Local exchange ID
+ */
+static unsigned int fc_new_xchg_id ( void ) {
+	static uint16_t next_id = 0x0000;
+
+	/* We must avoid using FC_RX_ID_UNKNOWN (0xffff) */
+	next_id += 2;
+	return next_id;
+}
+
+/**
+ * Create local Fibre Channel sequence identifier
+ *
+ * @ret seq_id		Local sequence identifier
+ */
+static unsigned int fc_new_seq_id ( void ) {
+	static uint8_t seq_id = 0x00;
+
+	return (++seq_id);
+}
+
+/**
+ * Free Fibre Channel exchange
+ *
+ * @v refcnt		Reference count
+ */
+static void fc_xchg_free ( struct refcnt *refcnt ) {
+	struct fc_exchange *xchg =
+		container_of ( refcnt, struct fc_exchange, refcnt );
+
+	assert ( ! timer_running ( &xchg->timer ) );
+	assert ( list_empty ( &xchg->list ) );
+
+	fc_port_put ( xchg->port );
+	free ( xchg );
+}
+
+/**
+ * Close Fibre Channel exchange
+ *
+ * @v xchg		Fibre Channel exchange
+ * @v rc		Reason for close
+ */
+static void fc_xchg_close ( struct fc_exchange *xchg, int rc ) {
+	struct fc_port *port = xchg->port;
+
+	if ( rc != 0 ) {
+		DBGC2 ( port, "FCXCHG %s/%04x closed: %s\n",
+			port->name, xchg->xchg_id, strerror ( rc ) );
+	}
+
+	/* Stop timer */
+	stop_timer ( &xchg->timer );
+
+	/* If list still holds a reference, remove from list of open
+	 * exchanges and drop list's reference.
+	 */
+	if ( ! list_empty ( &xchg->list ) ) {
+		list_del ( &xchg->list );
+		INIT_LIST_HEAD ( &xchg->list );
+		ref_put ( &xchg->refcnt );
+	}
+
+	/* Shutdown interfaces */
+	intf_shutdown ( &xchg->ulp, rc );
+}
+
+/**
+ * Handle exchange timeout
+ *
+ * @v timer		Timeout timer
+ * @v over		Failure indicator
+ */
+static void fc_xchg_expired ( struct retry_timer *timer, int over __unused ) {
+	struct fc_exchange *xchg =
+		container_of ( timer, struct fc_exchange, timer );
+	struct fc_port *port = xchg->port;
+
+	DBGC ( port, "FCXCHG %s/%04x timed out\n", port->name, xchg->xchg_id );
+
+	/* Terminate the exchange */
+	fc_xchg_close ( xchg, -ETIMEDOUT );
+}
+
+/**
+ * Check Fibre Channel exchange window
+ *
+ * @v xchg		Fibre Channel exchange
+ * @ret len		Length opf window
+ */
+static size_t fc_xchg_window ( struct fc_exchange *xchg __unused ) {
+
+	/* We don't currently store the path MTU */
+	return FC_LOGIN_DEFAULT_MTU;
+}
+
+/**
+ * Allocate Fibre Channel I/O buffer
+ *
+ * @v xchg		Fibre Channel exchange
+ * @v len		Payload length
+ * @ret iobuf		I/O buffer, or NULL
+ */
+static struct io_buffer * fc_xchg_alloc_iob ( struct fc_exchange *xchg,
+					      size_t len ) {
+	struct fc_port *port = xchg->port;
+	struct io_buffer *iobuf;
+
+	iobuf = xfer_alloc_iob ( &port->transport,
+				 ( sizeof ( struct fc_frame_header ) + len ) );
+	if ( iobuf ) {
+		iob_reserve ( iobuf, sizeof ( struct fc_frame_header ) );
+	}
+	return iobuf;
+}
+
+/**
+ * Transmit data as part of a Fibre Channel exchange
+ *
+ * @v xchg		Fibre Channel exchange
+ * @v iobuf		I/O buffer
+ * @v meta		Data transfer metadata
+ * @ret rc		Return status code
+ */
+static int fc_xchg_tx ( struct fc_exchange *xchg, struct io_buffer *iobuf,
+			struct xfer_metadata *meta ) {
+	struct fc_port *port = xchg->port;
+	struct fc_frame_header *fchdr;
+	unsigned int r_ctl;
+	unsigned int f_ctl_es;
+	int rc;
+
+	/* Sanity checks */
+	if ( ! ( xchg->flags & FC_XCHG_SEQ_INITIATIVE ) ) {
+		DBGC ( port, "FCXCHG %s/%04x cannot transmit while not "
+		       "holding sequence initiative\n",
+		       port->name, xchg->xchg_id );
+		rc = -EBUSY;
+		goto done;
+	}
+
+	/* Calculate routing control */
+	if ( xchg->type == 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 {
+		r_ctl = FC_R_CTL_DATA;
+		switch ( meta->flags &
+			 ( XFER_FL_CMD_STAT | XFER_FL_RESPONSE ) ) {
+		case ( XFER_FL_CMD_STAT | XFER_FL_RESPONSE ):
+			r_ctl |= FC_R_CTL_CMD_STAT;
+			break;
+		case ( XFER_FL_CMD_STAT ):
+			r_ctl |= FC_R_CTL_UNSOL_CMD;
+			break;
+		case ( XFER_FL_RESPONSE ):
+			r_ctl |= FC_R_CTL_SOL_DATA;
+			break;
+		default:
+			r_ctl |= FC_R_CTL_UNSOL_DATA;
+			break;
+		}
+	}
+
+	/* Calculate exchange and sequence control */
+	f_ctl_es = 0;
+	if ( ! ( xchg->flags & FC_XCHG_ORIGINATOR ) )
+		f_ctl_es |= FC_F_CTL_ES_RESPONDER;
+	if ( xchg->flags & FC_XCHG_SEQ_FIRST )
+		f_ctl_es |= FC_F_CTL_ES_FIRST;
+	if ( meta->flags & XFER_FL_OUT )
+		f_ctl_es |= ( FC_F_CTL_ES_END | FC_F_CTL_ES_LAST );
+	if ( meta->flags & XFER_FL_OVER )
+		f_ctl_es |= ( FC_F_CTL_ES_END | FC_F_CTL_ES_TRANSFER );
+
+	/* Create frame header */
+	fchdr = iob_push ( iobuf, sizeof ( *fchdr ) );
+	memset ( fchdr, 0, sizeof ( *fchdr ) );
+	fchdr->r_ctl = r_ctl;
+	memcpy ( &fchdr->d_id, &xchg->peer_port_id, sizeof ( fchdr->d_id ) );
+	memcpy ( &fchdr->s_id, &port->port_id, sizeof ( fchdr->s_id ) );
+	fchdr->type = xchg->type;
+	fchdr->f_ctl_es = f_ctl_es;
+	fchdr->seq_id = xchg->seq_id;
+	fchdr->seq_cnt = htons ( xchg->seq_cnt++ );
+	fchdr->ox_id = htons ( ( xchg->flags & FC_XCHG_ORIGINATOR ) ?
+			       xchg->xchg_id : xchg->peer_xchg_id );
+	fchdr->rx_id = htons ( ( xchg->flags & FC_XCHG_ORIGINATOR ) ?
+			       xchg->peer_xchg_id : xchg->xchg_id );
+	if ( meta->flags & XFER_FL_ABS_OFFSET ) {
+		fchdr->f_ctl_misc |= FC_F_CTL_MISC_REL_OFF;
+		fchdr->parameter = htonl ( meta->offset );
+	}
+
+	/* Relinquish sequence initiative if applicable */
+	if ( meta->flags & XFER_FL_OVER ) {
+		xchg->flags &= ~( FC_XCHG_SEQ_INITIATIVE | FC_XCHG_SEQ_FIRST );
+		xchg->seq_cnt = 0;
+	}
+
+	/* Reset timeout */
+	start_timer_fixed ( &xchg->timer, FC_TIMEOUT );
+
+	/* Deliver frame */
+	if ( ( rc = xfer_deliver_iob ( &port->transport,
+				       iob_disown ( iobuf ) ) ) != 0 ) {
+		DBGC ( port, "FCXCHG %s/%04x cannot transmit: %s\n",
+		       port->name, xchg->xchg_id, strerror ( rc ) );
+		goto done;
+	}
+
+ done:
+	free_iob ( iobuf );
+	return rc;
+}
+
+/** Mapping from Fibre Channel routing control information to xfer metadata */
+static const uint8_t fc_r_ctl_info_meta_flags[ FC_R_CTL_INFO_MASK + 1 ] = {
+	[FC_R_CTL_UNCAT]	= ( 0 ),
+	[FC_R_CTL_SOL_DATA]	= ( XFER_FL_RESPONSE ),
+	[FC_R_CTL_UNSOL_CTRL]	= ( XFER_FL_CMD_STAT ),
+	[FC_R_CTL_SOL_CTRL]	= ( XFER_FL_CMD_STAT ),
+	[FC_R_CTL_UNSOL_DATA]	= ( 0 ),
+	[FC_R_CTL_DATA_DESC]	= ( XFER_FL_CMD_STAT ),
+	[FC_R_CTL_UNSOL_CMD]	= ( XFER_FL_CMD_STAT ),
+	[FC_R_CTL_CMD_STAT]	= ( XFER_FL_CMD_STAT | XFER_FL_RESPONSE ),
+};
+
+/**
+ * Receive data as part of a Fibre Channel exchange
+ *
+ * @v xchg		Fibre Channel exchange
+ * @v iobuf		I/O buffer
+ * @v meta		Data transfer metadata
+ * @ret rc		Return status code
+ */
+static int fc_xchg_rx ( struct fc_exchange *xchg, struct io_buffer *iobuf,
+			struct xfer_metadata *meta __unused ) {
+	struct fc_port *port = xchg->port;
+	struct fc_frame_header *fchdr = iobuf->data;
+	struct xfer_metadata fc_meta;
+	int rc;
+
+	/* Record peer exchange ID */
+	xchg->peer_xchg_id =
+		ntohs ( ( fchdr->f_ctl_es & FC_F_CTL_ES_RESPONDER ) ?
+			fchdr->rx_id : fchdr->ox_id );
+
+	/* Sequence checks */
+	if ( xchg->flags & FC_XCHG_SEQ_INITIATIVE ) {
+		DBGC ( port, "FCXCHG %s/%04x received frame while holding "
+		       "sequence initiative\n", port->name, xchg->xchg_id );
+		rc = -EBUSY;
+		goto done;
+	}
+	if ( ntohs ( fchdr->seq_cnt ) != xchg->seq_cnt ) {
+		DBGC ( port, "FCXCHG %s/%04x received out-of-order frame %d "
+		       "(expected %d)\n", port->name, xchg->xchg_id,
+		       ntohs ( fchdr->seq_cnt ), xchg->seq_cnt );
+		rc = -EPIPE;
+		goto done;
+	}
+	if ( xchg->seq_cnt == 0 )
+		xchg->seq_id = fchdr->seq_id;
+	xchg->seq_cnt++;
+	if ( fchdr->seq_id != xchg->seq_id ) {
+		DBGC ( port, "FCXCHG %s/%04x received frame for incorrect "
+		       "sequence %02x (expected %02x)\n", port->name,
+		       xchg->xchg_id, fchdr->seq_id, xchg->seq_id );
+		rc = -EPIPE;
+		goto done;
+	}
+
+	/* Check for end of sequence and transfer of sequence initiative */
+	if ( fchdr->f_ctl_es & FC_F_CTL_ES_END ) {
+		xchg->seq_cnt = 0;
+		if ( fchdr->f_ctl_es & FC_F_CTL_ES_TRANSFER ) {
+			xchg->flags |= FC_XCHG_SEQ_INITIATIVE;
+			xchg->seq_id = fc_new_seq_id();
+		}
+	}
+
+	/* Construct metadata */
+	memset ( &fc_meta, 0, sizeof ( fc_meta ) );
+	fc_meta.flags =
+		fc_r_ctl_info_meta_flags[ fchdr->r_ctl & FC_R_CTL_INFO_MASK ];
+	if ( fchdr->f_ctl_es & FC_F_CTL_ES_TRANSFER ) {
+		fc_meta.flags |= XFER_FL_OVER;
+	}
+	if ( ( fchdr->f_ctl_es & FC_F_CTL_ES_LAST ) &&
+	     ( fchdr->f_ctl_es & FC_F_CTL_ES_END ) ) {
+		fc_meta.flags |= XFER_FL_OUT;
+	}
+	if ( fchdr->f_ctl_misc & FC_F_CTL_MISC_REL_OFF ) {
+		fc_meta.flags |= XFER_FL_ABS_OFFSET;
+		fc_meta.offset = ntohl ( fchdr->parameter );
+	}
+
+	/* Reset timeout */
+	start_timer_fixed ( &xchg->timer, FC_TIMEOUT );
+
+	/* Deliver via exchange's ULP interface */
+	iob_pull ( iobuf, sizeof ( *fchdr ) );
+	if ( ( rc = xfer_deliver ( &xchg->ulp, iob_disown ( iobuf ),
+				   &fc_meta ) ) != 0 ) {
+		DBGC ( port, "FCXCHG %s/%04x cannot deliver frame: %s\n",
+		       port->name, xchg->xchg_id, strerror ( rc ) );
+		goto done;
+	}
+
+	/* Close exchange if applicable */
+	if ( ( fchdr->f_ctl_es & FC_F_CTL_ES_LAST ) &&
+	     ( fchdr->f_ctl_es & FC_F_CTL_ES_END ) ) {
+		fc_xchg_close ( xchg, 0 );
+	}
+
+ done:
+	free_iob ( iobuf );
+	return rc;
+}
+
+/** Fibre Channel exchange ULP interface operations */
+static struct interface_operation fc_xchg_ulp_op[] = {
+	INTF_OP ( xfer_deliver, struct fc_exchange *, fc_xchg_tx ),
+	INTF_OP ( xfer_alloc_iob, struct fc_exchange *, fc_xchg_alloc_iob ),
+	INTF_OP ( xfer_window, struct fc_exchange *, fc_xchg_window ),
+	INTF_OP ( intf_close, struct fc_exchange *, fc_xchg_close ),
+};
+
+/** Fibre Channel exchange ULP interface descriptor */
+static struct interface_descriptor fc_xchg_ulp_desc =
+	INTF_DESC ( struct fc_exchange, ulp, fc_xchg_ulp_op );
+
+/**
+ * Create new Fibre Channel exchange
+ *
+ * @v port		Fibre Channel port
+ * @v peer_port_id	Peer port ID
+ * @ret xchg		Exchange, or NULL
+ */
+static struct fc_exchange * fc_xchg_create ( struct fc_port *port,
+					     struct fc_port_id *peer_port_id,
+					     unsigned int type ) {
+	struct fc_exchange *xchg;
+
+	/* Allocate and initialise structure */
+	xchg = zalloc ( sizeof ( *xchg ) );
+	if ( ! xchg )
+		return NULL;
+	ref_init ( &xchg->refcnt, fc_xchg_free );
+	intf_init ( &xchg->ulp, &fc_xchg_ulp_desc, &xchg->refcnt );
+	timer_init ( &xchg->timer, fc_xchg_expired, &xchg->refcnt );
+	xchg->port = fc_port_get ( port );
+	memcpy ( &xchg->peer_port_id, peer_port_id,
+		 sizeof ( xchg->peer_port_id ) );
+	xchg->type = type;
+	xchg->xchg_id = fc_new_xchg_id();
+	xchg->peer_xchg_id = FC_RX_ID_UNKNOWN;
+	xchg->seq_id = fc_new_seq_id();
+
+	/* Transfer reference to list of exchanges and return */
+	list_add ( &xchg->list, &port->xchgs );
+	return xchg;
+}
+
+/**
+ * Originate a new Fibre Channel exchange
+ *
+ * @v parent		Interface to which to attach
+ * @v port		Fibre Channel port
+ * @v peer_port_id	Peer port ID
+ * @ret rc		Return status code
+ */
+int fc_xchg_originate ( struct interface *parent, struct fc_port *port,
+			struct fc_port_id *peer_port_id, unsigned int type ) {
+	struct fc_exchange *xchg;
+
+	/* Allocate and initialise structure */
+	xchg = fc_xchg_create ( port, peer_port_id, type );
+	if ( ! xchg )
+		return -ENOMEM;
+	xchg->flags = ( FC_XCHG_ORIGINATOR | FC_XCHG_SEQ_INITIATIVE |
+			FC_XCHG_SEQ_FIRST );
+
+	DBGC2 ( port, "FCXCHG %s/%04x originating to %s (type %02x)\n",
+		port->name, xchg->xchg_id, fc_id_ntoa ( &xchg->peer_port_id ),
+		xchg->type );
+
+	/* Attach to parent interface and return */
+	intf_plug_plug ( &xchg->ulp, parent );
+	return 0;
+}
+
+/**
+ * Open a new responder Fibre Channel exchange
+ *
+ * @v port		Fibre Channel port
+ * @v fchdr		Fibre Channel frame header
+ * @ret xchg		Fibre Channel exchange, or NULL
+ */
+static struct fc_exchange * fc_xchg_respond ( struct fc_port *port,
+					      struct fc_frame_header *fchdr ) {
+	struct fc_exchange *xchg;
+	struct fc_responder *responder;
+	unsigned int type = fchdr->type;
+	int rc;
+
+	/* Allocate and initialise structure */
+	xchg = fc_xchg_create ( port, &fchdr->s_id, type );
+	if ( ! xchg )
+		return NULL;
+	xchg->seq_id = fchdr->seq_id;
+
+	DBGC2 ( port, "FCXCHG %s/%04x responding to %s xchg %04x (type "
+		"%02x)\n", port->name, xchg->xchg_id,
+		fc_id_ntoa ( &xchg->peer_port_id ),
+		ntohs ( fchdr->ox_id ), xchg->type );
+
+	/* Find a responder, if any */
+	for_each_table_entry ( responder, FC_RESPONDERS ) {
+		if ( responder->type == type ) {
+			if ( ( rc = responder->respond ( &xchg->ulp, port,
+							 &fchdr->d_id,
+							 &fchdr->s_id ) ) !=0 ){
+				DBGC ( port, "FCXCHG %s/%04x could not "
+				       "respond: %s\n", port->name,
+				       xchg->xchg_id, strerror ( rc ) );
+			}
+		}
+		break;
+	}
+
+	/* We may or may not have a ULP attached at this point, but
+	 * the exchange does exist.
+	 */
+	return xchg;
+}
+
+/******************************************************************************
+ *
+ * Fibre Channel ports
+ *
+ ******************************************************************************
+ */
+
+/**
+ * Close Fibre Channel port
+ *
+ * @v port		Fibre Channel port
+ * @v rc		Reason for close
+ */
+static void fc_port_close ( struct fc_port *port, int rc ) {
+	struct fc_exchange *xchg;
+	struct fc_exchange *tmp;
+
+	DBGC ( port, "FCPORT %s closed\n", port->name );
+
+	/* Log out port, if necessary */
+	if ( fc_link_ok ( &port->link ) )
+		fc_port_logout ( port, rc );
+
+	/* Stop link monitor */
+	fc_link_stop ( &port->link );
+
+	/* Shut down interfaces */
+	intf_shutdown ( &port->transport, rc );
+	intf_shutdown ( &port->flogi, rc );
+
+	/* Shut down any remaining exchanges */
+	list_for_each_entry_safe ( xchg, tmp, &port->xchgs, list )
+		fc_xchg_close ( xchg, rc );
+
+	/* Remove from list of ports */
+	list_del ( &port->list );
+	INIT_LIST_HEAD ( &port->list );
+}
+
+/**
+ * Identify Fibre Channel exchange by local exchange ID
+ *
+ * @v port		Fibre Channel port
+ * @v xchg_id		Local exchange ID
+ * @ret xchg		Fibre Channel exchange, or NULL
+ */
+static struct fc_exchange * fc_port_demux ( struct fc_port *port,
+					    unsigned int xchg_id ) {
+	struct fc_exchange *xchg;
+
+	list_for_each_entry ( xchg, &port->xchgs, list ) {
+		if ( xchg->xchg_id == xchg_id )
+			return xchg;
+	}
+	return NULL;
+}
+
+/**
+ * Handle received frame from Fibre Channel port
+ *
+ * @v port		Fibre Channel port
+ * @v iobuf		I/O buffer
+ * @v meta		Data transfer metadata
+ * @ret rc		Return status code
+ */
+static int fc_port_deliver ( struct fc_port *port, struct io_buffer *iobuf,
+			     struct xfer_metadata *meta ) {
+	struct fc_frame_header *fchdr = iobuf->data;
+	unsigned int xchg_id;
+	struct fc_exchange *xchg;
+	int rc;
+
+	/* Sanity check */
+	if ( iob_len ( iobuf ) < sizeof ( *fchdr ) ) {
+		DBGC ( port, "FCPORT %s received underlength frame (%zd "
+		       "bytes)\n", port->name, iob_len ( iobuf ) );
+		rc = -EINVAL;
+		goto err_sanity;
+	}
+
+	/* Verify local port ID */
+	if ( ( memcmp ( &fchdr->d_id, &port->port_id,
+			sizeof ( fchdr->d_id ) ) != 0 ) &&
+	     ( memcmp ( &fchdr->d_id, &fc_f_port_id,
+			sizeof ( fchdr->d_id ) ) != 0 ) &&
+	     ( memcmp ( &port->port_id, &fc_empty_port_id,
+			sizeof ( port->port_id ) ) != 0 ) ) {
+		DBGC ( port, "FCPORT %s received frame for incorrect port ID "
+		       "%s\n", port->name, fc_id_ntoa ( &fchdr->d_id ) );
+		rc = -ENOTCONN;
+		goto err_port_id;
+	}
+
+	/* Demultiplex amongst active exchanges */
+	xchg_id = ntohs ( ( fchdr->f_ctl_es & FC_F_CTL_ES_RESPONDER ) ?
+			  fchdr->ox_id : fchdr->rx_id );
+	xchg = fc_port_demux ( port, xchg_id );
+
+	/* If we have no active exchange and this frame starts a new
+	 * exchange, try to create a new responder exchange
+	 */
+	if ( ( fchdr->f_ctl_es & FC_F_CTL_ES_FIRST ) &&
+	     ( fchdr->seq_cnt == 0 ) ) {
+
+		/* Create new exchange */
+		xchg = fc_xchg_respond ( port, fchdr );
+		if ( ! xchg ) {
+			DBGC ( port, "FCPORT %s cannot create new exchange\n",
+			       port->name );
+			rc = -ENOMEM;
+			goto err_respond;
+		}
+	}
+
+	/* Fail if no exchange exists */
+	if ( ! xchg ) {
+		DBGC ( port, "FCPORT %s xchg %04x unknown\n",
+		       port->name, xchg_id );
+		rc = -ENOTCONN;
+		goto err_no_xchg;
+	}
+
+	/* Pass received frame to exchange */
+	ref_get ( &xchg->refcnt );
+	if ( ( rc = fc_xchg_rx ( xchg, iob_disown ( iobuf ), meta ) ) != 0 )
+		goto err_xchg_rx;
+
+ err_xchg_rx:
+	ref_put ( &xchg->refcnt );
+ err_no_xchg:
+ err_respond:
+ err_port_id:
+ err_sanity:
+	free_iob ( iobuf );
+	return rc;
+}
+
+/**
+ * Log in Fibre Channel port
+ *
+ * @v port		Fibre Channel port
+ * @v port_id		Local port ID
+ * @v link_node_wwn	Link node name
+ * @v link_port_wwn	Link port name
+ * @v has_fabric	Link is to a fabric
+ * @ret rc		Return status code
+ */
+int fc_port_login ( struct fc_port *port, struct fc_port_id *port_id,
+		    const struct fc_name *link_node_wwn,
+		    const struct fc_name *link_port_wwn, int has_fabric ) {
+	struct fc_peer *peer;
+	struct fc_peer *tmp;
+
+	/* Perform implicit logout if logged in and details differ */
+	if ( fc_link_ok ( &port->link ) &&
+	     ( ( ( !! ( port->flags & FC_PORT_HAS_FABRIC ) ) !=
+		 ( !! has_fabric ) ) ||
+	       ( memcmp ( &port->link_node_wwn, link_node_wwn,
+			  sizeof ( port->link_node_wwn ) ) != 0 ) ||
+	       ( memcmp ( &port->link_port_wwn, link_port_wwn,
+			  sizeof ( port->link_port_wwn ) ) != 0 ) ||
+	       ( memcmp ( &port->port_id, port_id,
+			  sizeof ( port->port_id ) ) != 0 ) ) ) {
+		fc_port_logout ( port, 0 );
+	}
+
+	/* Log in, if applicable */
+	if ( ! fc_link_ok ( &port->link ) ) {
+
+		/* Record link port name */
+		memcpy ( &port->link_node_wwn, link_node_wwn,
+			 sizeof ( port->link_node_wwn ) );
+		memcpy ( &port->link_port_wwn, link_port_wwn,
+			 sizeof ( port->link_port_wwn ) );
+		DBGC ( port, "FCPORT %s logged in to %s",
+		       port->name, fc_ntoa ( &port->link_node_wwn ) );
+		DBGC ( port, " port %s\n", fc_ntoa ( &port->link_port_wwn ) );
+
+		/* Calculate local (and possibly remote) port IDs */
+		if ( has_fabric ) {
+			port->flags |= FC_PORT_HAS_FABRIC;
+			memcpy ( &port->port_id, port_id,
+				 sizeof ( port->port_id ) );
+		} else {
+			port->flags &= ~FC_PORT_HAS_FABRIC;
+			if ( memcmp ( &port->port_wwn, link_port_wwn,
+				      sizeof ( port->port_wwn ) ) > 0 ) {
+				memcpy ( &port->port_id, &fc_ptp_high_port_id,
+					 sizeof ( port->port_id ) );
+				memcpy ( &port->ptp_link_port_id,
+					 &fc_ptp_low_port_id,
+					 sizeof ( port->ptp_link_port_id ) );
+			} else {
+				memcpy ( &port->port_id, &fc_ptp_low_port_id,
+					 sizeof ( port->port_id ) );
+				memcpy ( &port->ptp_link_port_id,
+					 &fc_ptp_high_port_id,
+					 sizeof ( port->ptp_link_port_id ) );
+			}
+		}
+		DBGC ( port, "FCPORT %s logged in via a %s, with local ID "
+		       "%s\n", port->name,
+		       ( ( port->flags & FC_PORT_HAS_FABRIC ) ?
+			 "fabric" : "point-to-point link" ),
+		       fc_id_ntoa ( &port->port_id ) );
+	}
+
+	/* Record login */
+	fc_link_up ( &port->link );
+
+	/* Notify peers of link state change */
+	list_for_each_entry_safe ( peer, tmp, &fc_peers, list )
+		fc_link_examine ( &peer->link );
+
+	return 0;
+}
+
+/**
+ * Log out Fibre Channel port
+ *
+ * @v port		Fibre Channel port
+ * @v rc		Reason for logout
+ */
+void fc_port_logout ( struct fc_port *port, int rc ) {
+	struct fc_peer *peer;
+	struct fc_peer *tmp;
+
+	DBGC ( port, "FCPORT %s logged out: %s\n",
+	       port->name, strerror ( rc ) );
+
+	/* Erase port details */
+	memset ( &port->port_id, 0, sizeof ( port->port_id ) );
+
+	/* Record logout */
+	fc_link_err ( &port->link, rc );
+
+	/* Notify peers of link state change */
+	list_for_each_entry_safe ( peer, tmp, &fc_peers, list )
+		fc_link_examine ( &peer->link );
+}
+
+/**
+ * Handle FLOGI completion
+ *
+ * @v port		Fibre Channel port
+ * @v rc		Reason for completion
+ */
+static void fc_port_flogi_done ( struct fc_port *port, int rc ) {
+
+	intf_restart ( &port->flogi, rc );
+
+	if ( rc != 0 )
+		fc_port_logout ( port, rc );
+}
+
+/**
+ * Examine Fibre Channel port link state
+ *
+ * @ link		Fibre Channel link state monitor
+ */
+static void fc_port_examine ( struct fc_link_state *link ) {
+	struct fc_port *port = container_of ( link, struct fc_port, link );
+	int rc;
+
+	/* Do nothing if already logged in */
+	if ( fc_link_ok ( &port->link ) )
+		return;
+
+	DBGC ( port, "FCPORT %s attempting login\n", port->name );
+
+	/* Try to create FLOGI ELS */
+	intf_restart ( &port->flogi, -ECANCELED );
+	if ( ( rc = fc_els_flogi ( &port->flogi, port ) ) != 0 ) {
+		DBGC ( port, "FCPORT %s could not initiate FLOGI: %s\n",
+		       port->name, strerror ( rc ) );
+		fc_port_logout ( port, rc );
+		return;
+	}
+}
+
+/**
+ * Handle change of flow control window
+ *
+ * @v port		Fibre Channel port
+ */
+static void fc_port_window_changed ( struct fc_port *port ) {
+	size_t window;
+
+	/* Check if transport layer is ready */
+	window = xfer_window ( &port->transport );
+	if ( window > 0 ) {
+
+		/* Transport layer is ready.  Start login if the link
+		 * is not already up.
+		 */
+		if ( ! fc_link_ok ( &port->link ) )
+			fc_link_start ( &port->link );
+
+	} else {
+
+		/* Transport layer is not ready.  Log out port and
+		 * wait for transport layer before attempting log in
+		 * again.
+		 */
+		fc_port_logout ( port, -ENOTCONN );
+		fc_link_stop ( &port->link );
+	}
+}
+
+/** Fibre Channel port transport interface operations */
+static struct interface_operation fc_port_transport_op[] = {
+	INTF_OP ( xfer_deliver, struct fc_port *, fc_port_deliver ),
+	INTF_OP ( xfer_window_changed, struct fc_port *,
+		  fc_port_window_changed ),
+	INTF_OP ( intf_close, struct fc_port *, fc_port_close ),
+};
+
+/** Fibre Channel port transport interface descriptor */
+static struct interface_descriptor fc_port_transport_desc =
+	INTF_DESC ( struct fc_port, transport, fc_port_transport_op );
+
+/** Fibre Channel port FLOGI interface operations */
+static struct interface_operation fc_port_flogi_op[] = {
+	INTF_OP ( intf_close, struct fc_port *, fc_port_flogi_done ),
+};
+
+/** Fibre Channel port FLOGI interface descriptor */
+static struct interface_descriptor fc_port_flogi_desc =
+	INTF_DESC ( struct fc_port, flogi, fc_port_flogi_op );
+
+/**
+ * Create Fibre Channel port
+ *
+ * @v transport		Transport interface
+ * @v node		Fibre Channel node name
+ * @v port		Fibre Channel port name
+ * @ret rc		Return status code
+ */
+int fc_port_open ( struct interface *transport, const struct fc_name *node_wwn,
+		   const struct fc_name *port_wwn ) {
+	static unsigned int portindex = 0;
+	struct fc_port *port;
+
+	/* Allocate and initialise structure */
+	port = zalloc ( sizeof ( *port ) );
+	if ( ! port )
+		return -ENOMEM;
+	ref_init ( &port->refcnt, NULL );
+	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 );
+	list_add ( &port->list, &fc_ports );
+	INIT_LIST_HEAD ( &port->xchgs );
+	memcpy ( &port->node_wwn, node_wwn, sizeof ( port->node_wwn ) );
+	memcpy ( &port->port_wwn, port_wwn, sizeof ( port->port_wwn ) );
+
+	/* Create device name */
+	snprintf ( port->name, sizeof ( port->name ), "fc%d", portindex++ );
+
+	DBGC ( port, "FCPORT %s opened as %s",
+	       port->name, fc_ntoa ( &port->node_wwn ) );
+	DBGC ( port, " port %s\n", fc_ntoa ( &port->port_wwn ) );
+
+	/* Attach to transport layer, mortalise self, and return */
+	intf_plug_plug ( &port->transport, transport );
+	ref_put ( &port->refcnt );
+	return 0;
+}
+
+/**
+ * Find Fibre Channel port by name
+ *
+ * @v name		Fibre Channel port name
+ * @ret port		Fibre Channel port, or NULL
+ */
+struct fc_port * fc_port_find ( const char *name ) {
+	struct fc_port *port;
+
+	list_for_each_entry ( port, &fc_ports, list ) {
+		if ( strcmp ( name, port->name ) == 0 )
+			return port;
+	}
+	return NULL;
+}
+
+/**
+ * Find Fibre Channel port by link node name
+ *
+ * @v link_node_wwn	Link node name
+ * @ret port		Fibre Channel port, or NULL
+ */
+static struct fc_port *
+fc_port_find_link_wwn ( struct fc_name *link_node_wwn ) {
+	struct fc_port *port;
+
+	list_for_each_entry ( port, &fc_ports, list ) {
+		if ( fc_link_ok ( &port->link ) &&
+		     ( memcmp ( &port->link_node_wwn, link_node_wwn,
+				sizeof ( port->link_node_wwn ) ) == 0 ) ) {
+			return port;
+		}
+	}
+	return NULL;
+}
+
+/******************************************************************************
+ *
+ * Fibre Channel peers
+ *
+ ******************************************************************************
+ */
+
+/**
+ * Close Fibre Channel peer
+ *
+ * @v peer		Fibre Channel peer
+ * @v rc		Reason for close
+ */
+static void fc_peer_close ( struct fc_peer *peer, int rc ) {
+
+	DBGC ( peer, "FCPEER %s closed: %s\n",
+	       fc_ntoa ( &peer->node_wwn ) , strerror ( rc ) );
+
+	/* Sanity check */
+	assert ( list_empty ( &peer->ulps ) );
+
+	/* Stop link timer */
+	fc_link_stop ( &peer->link );
+
+	/* Shut down interfaces */
+	intf_shutdown ( &peer->plogi, rc );
+
+	/* Remove from list of peers */
+	list_del ( &peer->list );
+	INIT_LIST_HEAD ( &peer->list );
+}
+
+/**
+ * Increment Fibre Channel peer active usage count
+ *
+ * @v peer		Fibre Channel peer
+ */
+static void fc_peer_increment ( struct fc_peer *peer ) {
+
+	/* Increment our usage count */
+	peer->usage++;
+}
+
+/**
+ * Decrement Fibre Channel peer active usage count
+ *
+ * @v peer		Fibre Channel peer
+ */
+static void fc_peer_decrement ( struct fc_peer *peer ) {
+
+	/* Sanity check */
+	assert ( peer->usage > 0 );
+
+	/* Decrement our usage count and log out if we reach zero */
+	if ( peer->usage-- == 0 )
+		fc_peer_logout ( peer, 0 );
+}
+
+/**
+ * Log in Fibre Channel peer
+ *
+ * @v peer		Fibre Channel peer
+ * @v port		Fibre Channel port
+ * @v port_id		Port ID
+ * @ret rc		Return status code
+ */
+int fc_peer_login ( struct fc_peer *peer, struct fc_port *port,
+		    struct fc_port_id *port_id ) {
+	struct fc_ulp *ulp;
+	struct fc_ulp *tmp;
+
+	/* Perform implicit logout if logged in and details differ */
+	if ( fc_link_ok ( &peer->link ) &&
+	     ( ( peer->port != port ) ||
+	       ( memcmp ( &peer->port_id, port_id,
+			  sizeof ( peer->port_id ) ) !=0 ) ) ) {
+		fc_peer_logout ( peer, 0 );
+	}
+
+	/* Log in, if applicable */
+	if ( ! fc_link_ok ( &peer->link ) ) {
+
+		/* Record peer details */
+		assert ( peer->port == NULL );
+		peer->port = fc_port_get ( port );
+		memcpy ( &peer->port_id, port_id, sizeof ( peer->port_id ) );
+		DBGC ( peer, "FCPEER %s logged in via %s as %s\n",
+		       fc_ntoa ( &peer->node_wwn ), peer->port->name,
+		       fc_id_ntoa ( &peer->port_id ) );
+
+		/* Add login reference */
+		fc_peer_get ( peer );
+	}
+
+	/* Record login */
+	fc_link_up ( &peer->link );
+
+	/* Notify ULPs of link state change */
+	list_for_each_entry_safe ( ulp, tmp, &peer->ulps, list )
+		fc_link_examine ( &ulp->link );
+
+	return 0;
+}
+
+/**
+ * Log out Fibre Channel peer
+ *
+ * @v peer		Fibre Channel peer
+ * @v rc		Reason for logout
+ */
+void fc_peer_logout ( struct fc_peer *peer, int rc ) {
+	struct fc_ulp *ulp;
+	struct fc_ulp *tmp;
+
+	DBGC ( peer, "FCPEER %s logged out: %s\n",
+	       fc_ntoa ( &peer->node_wwn ), strerror ( rc ) );
+
+	/* Drop login reference, if applicable */
+	if ( fc_link_ok ( &peer->link ) )
+		fc_peer_put ( peer );
+
+	/* Erase peer details */
+	fc_port_put ( peer->port );
+	peer->port = NULL;
+
+	/* Record logout */
+	fc_link_err ( &peer->link, rc );
+
+	/* Notify ULPs of link state change */
+	list_for_each_entry_safe ( ulp, tmp, &peer->ulps, list )
+		fc_link_examine ( &ulp->link );
+
+	/* Close peer if there are no active users */
+	if ( peer->usage == 0 )
+		fc_peer_close ( peer, rc );
+}
+
+/**
+ * Handle PLOGI completion
+ *
+ * @v peer		Fibre Channel peer
+ * @v rc		Reason for completion
+ */
+static void fc_peer_plogi_done ( struct fc_peer *peer, int rc ) {
+
+	intf_restart ( &peer->plogi, rc );
+
+	if ( rc != 0 )
+		fc_peer_logout ( peer, rc );
+}
+
+/**
+ * Examine Fibre Channel peer link state
+ *
+ * @ link		Fibre Channel link state monitor
+ */
+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 */
+	if ( peer->port && ( ! fc_link_ok ( &peer->port->link ) ) ) {
+		fc_peer_logout ( peer, -ENOTCONN );
+		return;
+	}
+
+	/* Do nothing if already logged in */
+	if ( fc_link_ok ( &peer->link ) )
+		return;
+
+	DBGC ( peer, "FCPEER %s attempting login\n",
+	       fc_ntoa ( &peer->node_wwn ) );
+
+	/* 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->node_wwn );
+	if ( ! port ) {
+		DBGC ( peer, "FCPEER %s could not find a point-to-point "
+		       "link\n", fc_ntoa ( &peer->node_wwn ) );
+		fc_peer_logout ( peer, -ENOENT );
+		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->node_wwn ), strerror ( rc ) );
+		fc_peer_logout ( peer, rc );
+		return;
+	}
+}
+
+/** Fibre Channel peer PLOGI interface operations */
+static struct interface_operation fc_peer_plogi_op[] = {
+	INTF_OP ( intf_close, struct fc_peer *, fc_peer_plogi_done ),
+};
+
+/** Fibre Channel peer PLOGI interface descriptor */
+static struct interface_descriptor fc_peer_plogi_desc =
+	INTF_DESC ( struct fc_peer, plogi, fc_peer_plogi_op );
+
+/**
+ * Create Fibre Channel peer
+ *
+ * @v node_wwn		Node name
+ * @ret peer		Fibre Channel peer, or NULL
+ */
+static struct fc_peer * fc_peer_create ( const struct fc_name *node_wwn ) {
+	struct fc_peer *peer;
+
+	/* Allocate and initialise structure */
+	peer = zalloc ( sizeof ( *peer ) );
+	if ( ! peer )
+		return NULL;
+	ref_init ( &peer->refcnt, NULL );
+	fc_link_init ( &peer->link, fc_peer_examine, &peer->refcnt );
+	intf_init ( &peer->plogi, &fc_peer_plogi_desc, &peer->refcnt );
+	list_add ( &peer->list, &fc_peers );
+	memcpy ( &peer->node_wwn, node_wwn, sizeof ( peer->node_wwn ) );
+	INIT_LIST_HEAD ( &peer->ulps );
+
+	/* Start link monitor */
+	fc_link_start ( &peer->link );
+
+	DBGC ( peer, "FCPEER %s created\n", fc_ntoa ( &peer->node_wwn ) );
+	return peer;
+}
+
+/**
+ * Get Fibre Channel peer by node name
+ *
+ * @v node_wwn		Node name
+ * @ret peer		Fibre Channel peer, or NULL
+ */
+struct fc_peer * fc_peer_get_wwn ( const struct fc_name *node_wwn ) {
+	struct fc_peer *peer;
+
+	/* Look for an existing peer */
+	list_for_each_entry ( peer, &fc_peers, list ) {
+		if ( memcmp ( &peer->node_wwn, node_wwn,
+			      sizeof ( peer->node_wwn ) ) == 0 )
+			return fc_peer_get ( peer );
+	}
+
+	/* Create a new peer */
+	peer = fc_peer_create ( node_wwn );
+	if ( ! peer )
+		return NULL;
+
+	return peer;
+}
+
+/**
+ * Get Fibre Channel peer by port ID
+ *
+ * @v port		Fibre Channel port
+ * @v peer_port_id	Peer port ID
+ * @ret peer		Fibre Channel peer, or NULL
+ */
+struct fc_peer * fc_peer_get_port_id ( struct fc_port *port,
+				       const struct fc_port_id *peer_port_id ){
+	struct fc_peer *peer;
+
+	/* Look for an existing peer */
+	list_for_each_entry ( peer, &fc_peers, list ) {
+		if ( ( peer->port == port ) &&
+		     ( memcmp ( &peer->port_id, peer_port_id,
+				sizeof ( peer->port_id ) ) == 0 ) )
+			return fc_peer_get ( peer );
+	}
+
+	/* Cannot create a new peer, since we have no port name to use */
+	return NULL;
+}
+
+/******************************************************************************
+ *
+ * Fibre Channel upper-layer protocols
+ *
+ ******************************************************************************
+ */
+
+/**
+ * Close Fibre Channel upper-layer protocol
+ *
+ * @v ulp		Fibre Channel upper-layer protocol
+ * @v rc		Reason for close
+ */
+static void fc_ulp_close ( struct fc_ulp *ulp, int rc ) {
+
+	DBGC ( ulp, "FCULP %s/%02x closed: %s\n",
+	       fc_ntoa ( &ulp->peer->node_wwn ), ulp->type, strerror ( rc ) );
+
+	/* Sanity check */
+	assert ( ulp->usage == 0 );
+
+	/* Stop link monitor */
+	fc_link_stop ( &ulp->link );
+
+	/* Shut down interfaces */
+	intf_shutdown ( &ulp->prli, rc );
+
+	/* Remove from list of ULPs */
+	list_del ( &ulp->list );
+	INIT_LIST_HEAD ( &ulp->list );
+
+	/* Drop peer reference */
+	fc_peer_put ( ulp->peer );
+	ulp->peer = NULL;
+}
+
+/**
+ * Increment Fibre Channel upper-layer protocol active usage count
+ *
+ * @v ulp		Fibre Channel ulp
+ */
+void fc_ulp_increment ( struct fc_ulp *ulp ) {
+
+	/* Increment peer's usage count */
+	fc_peer_increment ( ulp->peer );
+
+	/* Increment our usage count */
+	ulp->usage++;
+}
+
+/**
+ * Decrement Fibre Channel upper-layer protocol active usage count
+ *
+ * @v ulp		Fibre Channel ulp
+ */
+void fc_ulp_decrement ( struct fc_ulp *ulp ) {
+	struct fc_peer *peer = ulp->peer;
+
+	/* Sanity check */
+	assert ( ulp->usage > 0 );
+
+	/* Decrement our usage count and log out if we reach zero */
+	if ( ulp->usage-- == 0 )
+		fc_ulp_logout ( ulp, 0 );
+
+	/* Decrement our peer's usage count */
+	fc_peer_decrement ( peer );
+}
+
+/**
+ * Log in Fibre Channel upper-layer protocol
+ *
+ * @v ulp		Fibre Channel upper-layer protocol
+ * @v param		Service parameters
+ * @v param_len		Length of service parameters
+ * @v originated	Login was originated by us
+ * @ret rc		Return status code
+ */
+int fc_ulp_login ( struct fc_ulp *ulp, const void *param, size_t param_len,
+		   int originated ) {
+
+	/* Perform implicit logout if logged in and service parameters differ */
+	if ( fc_link_ok ( &ulp->link ) &&
+	     ( ( ulp->param_len != param_len ) ||
+	       ( memcmp ( ulp->param, param, ulp->param_len ) != 0 ) ) ) {
+		fc_ulp_logout ( ulp, 0 );
+	}
+
+	/* Log in, if applicable */
+	if ( ! fc_link_ok ( &ulp->link ) ) {
+
+		/* Record service parameters */
+		assert ( ulp->param == NULL );
+		assert ( ulp->param_len == 0 );
+		ulp->param = malloc ( param_len );
+		if ( ! ulp->param ) {
+			DBGC ( ulp, "FCULP %s/%02x could not record "
+			       "parameters\n",
+			       fc_ntoa ( &ulp->peer->node_wwn ), ulp->type );
+			return -ENOMEM;
+		}
+		memcpy ( ulp->param, param, param_len );
+		ulp->param_len = param_len;
+		DBGC ( ulp, "FCULP %s/%02x logged in with parameters:\n",
+		       fc_ntoa ( &ulp->peer->node_wwn ), ulp->type );
+		DBGC_HDA ( ulp, 0, ulp->param, ulp->param_len );
+
+		/* Add login reference */
+		fc_ulp_get ( ulp );
+	}
+
+	/* Record login */
+	fc_link_up ( &ulp->link );
+
+	/* Work around a bug in some versions of the Linux Fibre
+	 * Channel stack, which fail to fully initialise image pairs
+	 * established via a PRLI originated by the Linux stack
+	 * itself.
+	 */
+	if ( originated )
+		ulp->flags |= FC_ULP_ORIGINATED_LOGIN_OK;
+	if ( ! ( ulp->flags & FC_ULP_ORIGINATED_LOGIN_OK ) ) {
+		DBGC ( ulp, "FCULP %s/%02x sending extra PRLI to work around "
+		       "Linux bug\n",
+		       fc_ntoa ( &ulp->peer->node_wwn ), ulp->type );
+		fc_link_start ( &ulp->link );
+	}
+
+	return 0;
+}
+
+/**
+ * Log out Fibre Channel upper-layer protocol
+ *
+ * @v ulp		Fibre Channel upper-layer protocol
+ * @v rc		Reason for logout
+ */
+void fc_ulp_logout ( struct fc_ulp *ulp, int rc ) {
+
+	DBGC ( ulp, "FCULP %s/%02x logged out: %s\n",
+	       fc_ntoa ( &ulp->peer->node_wwn ), ulp->type, strerror ( rc ) );
+
+	/* Drop login reference, if applicable */
+	if ( fc_link_ok ( &ulp->link ) )
+		fc_ulp_put ( ulp );
+
+	/* Discard service parameters */
+	free ( ulp->param );
+	ulp->param = NULL;
+	ulp->param_len = 0;
+	ulp->flags = 0;
+
+	/* Record logout */
+	fc_link_err ( &ulp->link, rc );
+
+	/* Close ULP if there are no clients attached */
+	if ( ulp->usage == 0 )
+		fc_ulp_close ( ulp, rc );
+}
+
+/**
+ * Handle PRLI completion
+ *
+ * @v ulp		Fibre Channel upper-layer protocol
+ * @v rc		Reason for completion
+ */
+static void fc_ulp_prli_done ( struct fc_ulp *ulp, int rc ) {
+
+	intf_restart ( &ulp->prli, rc );
+
+	if ( rc != 0 )
+		fc_ulp_logout ( ulp, rc );
+}
+
+/**
+ * Examine Fibre Channel upper-layer protocol link state
+ *
+ * @ link		Fibre Channel link state monitor
+ */
+static void fc_ulp_examine ( struct fc_link_state *link ) {
+	struct fc_ulp *ulp = container_of ( link, struct fc_ulp, link );
+	int rc;
+
+	/* Check to see if underlying peer link has gone down */
+	if ( ! fc_link_ok ( &ulp->peer->link ) ) {
+		fc_ulp_logout ( ulp, -ENOTCONN );
+		return;
+	}
+
+	/* Do nothing if already logged in */
+	if ( fc_link_ok ( &ulp->link ) &&
+	     ( ulp->flags & FC_ULP_ORIGINATED_LOGIN_OK ) )
+		return;
+
+	DBGC ( ulp, "FCULP %s/%02x attempting login\n",
+	       fc_ntoa ( &ulp->peer->node_wwn ), ulp->type );
+
+	/* Try to create PRLI ELS */
+	intf_restart ( &ulp->prli, -ECANCELED );
+	if ( ( rc = fc_els_prli ( &ulp->prli, ulp->peer->port,
+				  &ulp->peer->port_id, ulp->type ) ) != 0 ) {
+		DBGC ( ulp, "FCULP %s/%02x could not initiate PRLI: %s\n",
+		       fc_ntoa ( &ulp->peer->node_wwn ), ulp->type,
+		       strerror ( rc ) );
+		fc_ulp_logout ( ulp, rc );
+		return;
+	}
+}
+
+/** Fibre Channel upper-layer protocol PRLI interface operations */
+static struct interface_operation fc_ulp_prli_op[] = {
+	INTF_OP ( intf_close, struct fc_ulp *, fc_ulp_prli_done ),
+};
+
+/** Fibre Channel upper-layer protocol PRLI interface descriptor */
+static struct interface_descriptor fc_ulp_prli_desc =
+	INTF_DESC ( struct fc_ulp, prli, fc_ulp_prli_op );
+
+/**
+ * Create Fibre Channel upper-layer protocl
+ *
+ * @v peer		Fibre Channel peer
+ * @v type		Type
+ * @ret ulp		Fibre Channel upper-layer protocol, or NULL
+ */
+static struct fc_ulp * fc_ulp_create ( struct fc_peer *peer,
+				       unsigned int type ) {
+	struct fc_ulp *ulp;
+
+	/* Allocate and initialise structure */
+	ulp = zalloc ( sizeof ( *ulp ) );
+	if ( ! ulp )
+		return NULL;
+	ref_init ( &ulp->refcnt, NULL );
+	fc_link_init ( &ulp->link, fc_ulp_examine, &ulp->refcnt );
+	intf_init ( &ulp->prli, &fc_ulp_prli_desc, &ulp->refcnt );
+	ulp->peer = fc_peer_get ( peer );
+	list_add ( &ulp->list, &peer->ulps );
+	ulp->type = type;
+
+	/* Start link state monitor */
+	fc_link_start ( &ulp->link );
+
+	DBGC ( ulp, "FCULP %s/%02x created\n",
+	       fc_ntoa ( &ulp->peer->node_wwn ), ulp->type );
+	return ulp;
+}
+
+/**
+ * Get Fibre Channel upper-layer protocol by peer and type
+ *
+ * @v peer		Fibre Channel peer
+ * @v type		Type
+ * @ret ulp		Fibre Channel upper-layer protocol, or NULL
+ */
+static struct fc_ulp * fc_ulp_get_type ( struct fc_peer *peer,
+					 unsigned int type ) {
+	struct fc_ulp *ulp;
+
+	/* Look for an existing ULP */
+	list_for_each_entry ( ulp, &peer->ulps, list ) {
+		if ( ulp->type == type )
+			return fc_ulp_get ( ulp );
+	}
+
+	/* Create a new ULP */
+	ulp = fc_ulp_create ( peer, type );
+	if ( ! ulp )
+		return NULL;
+
+	return ulp;
+}
+
+/**
+ * Get Fibre Channel upper-layer protocol by port name and type
+ *
+ * @v node_wwn		Port name
+ * @v type		Type
+ * @ret ulp		Fibre Channel upper-layer protocol, or NULL
+ */
+struct fc_ulp * fc_ulp_get_wwn_type ( const struct fc_name *node_wwn,
+				      unsigned int type ) {
+	struct fc_ulp *ulp;
+	struct fc_peer *peer;
+
+	/* Get peer */
+	peer = fc_peer_get_wwn ( node_wwn );
+	if ( ! peer )
+		goto err_peer_get_wwn;
+
+	/* Get ULP */
+	ulp = fc_ulp_get_type ( peer, type );
+	if ( ! ulp )
+		goto err_ulp_get_type;
+
+	/* Drop temporary reference to peer */
+	fc_peer_put ( peer );
+
+	return ulp;
+
+	fc_ulp_put ( ulp );
+ err_ulp_get_type:
+	fc_peer_put ( peer );
+ err_peer_get_wwn:
+	return NULL;
+}
+
+/**
+ * Get Fibre Channel upper-layer protocol by port ID and type
+ *
+ * @v port		Fibre Channel port
+ * @v peer_port_id	Peer port ID
+ * @v type		Type
+ * @ret ulp		Fibre Channel upper-layer protocol, or NULL
+ */
+struct fc_ulp * fc_ulp_get_port_id_type ( struct fc_port *port,
+					  const struct fc_port_id *peer_port_id,
+					  unsigned int type ) {
+	struct fc_ulp *ulp;
+	struct fc_peer *peer;
+
+	/* Get peer */
+	peer = fc_peer_get_port_id ( port, peer_port_id );
+	if ( ! peer )
+		goto err_peer_get_wwn;
+
+	/* Get ULP */
+	ulp = fc_ulp_get_type ( peer, type );
+	if ( ! ulp )
+		goto err_ulp_get_type;
+
+	/* Drop temporary reference to peer */
+	fc_peer_put ( peer );
+
+	return ulp;
+
+	fc_ulp_put ( ulp );
+ err_ulp_get_type:
+	fc_peer_put ( peer );
+ err_peer_get_wwn:
+	return NULL;
+}
diff --git a/src/net/fcels.c b/src/net/fcels.c
new file mode 100644
index 000000000..63063ca35
--- /dev/null
+++ b/src/net/fcels.c
@@ -0,0 +1,1162 @@
+/*
+ * 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 <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <byteswap.h>
+#include <ipxe/interface.h>
+#include <ipxe/xfer.h>
+#include <ipxe/iobuf.h>
+#include <ipxe/process.h>
+#include <ipxe/fc.h>
+#include <ipxe/fcels.h>
+
+/** @file
+ *
+ * Fibre Channel Extended Link Services
+ *
+ */
+
+/** Fibre Channel ELS transaction debug message format */
+#define FCELS_FMT "FCELS %s %s %s %s"
+
+/** Fibre Channel ELS transaction debug message arguments */
+#define FCELS_ARGS( els )						\
+	(els)->port->name,						\
+	( (els)->handler ? (els)->handler->name : "unknown ELS" ),	\
+	( fc_els_is_request ( els ) ? "to" : "from" ),			\
+	fc_id_ntoa ( &(els)->peer_port_id )
+
+struct fc_els_handler fc_els_unknown_handler __fc_els_handler;
+
+/**
+ * Free Fibre Channel ELS transaction
+ *
+ * @v refcnt		Reference count
+ */
+static void fc_els_free ( struct refcnt *refcnt ) {
+	struct fc_els *els = container_of ( refcnt, struct fc_els, refcnt );
+
+	assert ( ! process_running ( &els->process ) );
+	fc_port_put ( els->port );
+	free ( els );
+}
+
+/**
+ * Close Fibre Channel ELS transaction
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @v rc		Reason for close
+ */
+static void fc_els_close ( struct fc_els *els, int rc ) {
+
+	if ( rc != 0 ) {
+		DBGC ( els, FCELS_FMT " complete (%s)\n",
+		       FCELS_ARGS ( els ), strerror ( rc ) );
+	}
+
+	/* Stop process */
+	process_del ( &els->process );
+
+	/* Shut down interfaces */
+	intf_shutdown ( &els->xchg, rc );
+	intf_shutdown ( &els->job, rc );
+}
+
+/**
+ * Detect Fibre Channel ELS frame handler
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @v command		ELS command code
+ * @ret handler		ELS handler, or NULL
+ */
+static struct fc_els_handler * fc_els_detect ( struct fc_els *els,
+					       const void *data,
+					       size_t len ) {
+	const struct fc_els_frame_common *frame = data;
+	struct fc_els_handler *handler;
+	int rc;
+
+	/* Sanity check */
+	if ( len < sizeof ( *frame ) )
+		return NULL;
+
+	/* Try each handler in turn */
+	for_each_table_entry ( handler, FC_ELS_HANDLERS ) {
+		if ( ( rc = handler->detect ( els, data, len ) ) == 0 )
+			return handler;
+	}
+
+	return NULL;
+}
+
+/**
+ * Transmit Fibre Channel ELS frame
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @v data		Data to transmit
+ * @v len		Length of data
+ * @ret rc		Return status code
+ */
+int fc_els_tx ( struct fc_els *els, const void *data, size_t len ) {
+	struct xfer_metadata meta = {
+		.flags = ( fc_els_is_request ( els ) ?
+			   XFER_FL_OVER : ( XFER_FL_RESPONSE | XFER_FL_OUT ) ),
+	};
+	int rc;
+
+	DBGC2 ( els, FCELS_FMT " transmitting:\n", FCELS_ARGS ( els ) );
+	DBGC2_HDA ( els, 0, data, len );
+
+	/* Transmit frame */
+	if ( ( rc = xfer_deliver_raw_meta ( &els->xchg, data, len,
+					    &meta ) ) != 0 ) {
+		DBGC ( els, FCELS_FMT " could not deliver frame: %s\n",
+		       FCELS_ARGS ( els ), strerror ( rc ) );
+		return rc;
+	}
+
+	return 0;
+}
+
+/**
+ * Receive Fibre Channel ELS frame
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @v iobuf		I/O buffer
+ * @v meta		Data transfer metadata
+ * @ret rc		Return status code
+ */
+static int fc_els_rx ( struct fc_els *els,
+		       struct io_buffer *iobuf,
+		       struct xfer_metadata *meta __unused ) {
+	struct fc_els_frame_common *frame = iobuf->data;
+	size_t len = iob_len ( iobuf );
+	int ( * rx ) ( struct fc_els *els, const void *data, size_t len );
+	int rc;
+
+	/* Sanity check */
+	if ( len < sizeof ( *frame ) ) {
+		DBGC ( els, FCELS_FMT " received underlength frame:\n",
+		       FCELS_ARGS ( els ) );
+		DBGC_HDA ( els, 0, frame, len );
+		rc = -EINVAL;
+		goto done;
+	}
+
+	/* Check for rejection responses */
+	if ( fc_els_is_request ( els ) &&
+	     ( frame->command != FC_ELS_LS_ACC ) ) {
+		DBGC ( els, FCELS_FMT " rejected:\n", FCELS_ARGS ( els ) );
+		DBGC_HDA ( els, 0, frame, len );
+		rc = -EACCES;
+		goto done;
+	}
+
+	/* Determine handler, if necessary */
+	if ( ! els->handler )
+		els->handler = fc_els_detect ( els, frame, len );
+	if ( ! els->handler )
+		els->handler = &fc_els_unknown_handler;
+
+	DBGC2 ( els, FCELS_FMT " received:\n", FCELS_ARGS ( els ) );
+	DBGC2_HDA ( els, 0, frame, len );
+
+	/* Handle received frame */
+	rx = ( fc_els_is_request ( els ) ?
+	       els->handler->rx_response : els->handler->rx_request );
+	if ( ( rc = rx ( els, frame, len ) ) != 0 ) {
+		DBGC ( els, FCELS_FMT " could not handle received frame: "
+		       "%s\n", FCELS_ARGS ( els ), strerror ( rc ) );
+		DBGC_HDA ( els, 0, frame, len );
+		goto done;
+	}
+
+	/* Free I/O buffer.  Do this before transmitting response to
+	 * minimise memory consumption.
+	 */
+	free_iob ( iob_disown ( iobuf ) );
+
+	/* Transmit response if applicable */
+	if ( ( ! fc_els_is_request ( els ) ) &&
+	     ( ( rc = els->handler->tx_response ( els ) ) != 0 ) ) {
+		DBGC ( els, FCELS_FMT " could not transmit response: %s\n",
+		       FCELS_ARGS ( els ), strerror ( rc ) );
+		goto done;
+	}
+
+ done:
+	/* Free I/O buffer */
+	free_iob ( iobuf );
+
+	/* Close transaction */
+	fc_els_close ( els, rc );
+
+	return rc;
+}
+
+/** Fibre Channel ELS exchange interface operations */
+static struct interface_operation fc_els_xchg_op[] = {
+	INTF_OP ( xfer_deliver, struct fc_els *, fc_els_rx ),
+	INTF_OP ( intf_close, struct fc_els *, fc_els_close ),
+};
+
+/** Fibre Channel ELS exchange interface descriptor */
+static struct interface_descriptor fc_els_xchg_desc =
+	INTF_DESC ( struct fc_els, xchg, fc_els_xchg_op );
+
+/** Fibre Channel ELS job control interface operations */
+static struct interface_operation fc_els_job_op[] = {
+	INTF_OP ( intf_close, struct fc_els *, fc_els_close ),
+};
+
+/** Fibre Channel ELS job control interface descriptor */
+static struct interface_descriptor fc_els_job_desc =
+	INTF_DESC ( struct fc_els, job, fc_els_job_op );
+
+/**
+ * Fibre Channel ELS process
+ *
+ * @v process		Process
+ */
+static void fc_els_step ( struct process *process ) {
+	struct fc_els *els =
+		container_of ( process, struct fc_els, process );
+	int rc;
+
+	/* Sanity check */
+	assert ( fc_els_is_request ( els ) );
+
+	/* Stop process */
+	process_del ( &els->process );
+
+	/* Create exchange */
+	if ( ( rc = fc_xchg_originate ( &els->xchg, els->port,
+					&els->peer_port_id,
+					FC_TYPE_ELS ) ) != 0 ) {
+		DBGC ( els, FCELS_FMT " could not create exchange: %s\n",
+		       FCELS_ARGS ( els ), strerror ( rc ) );
+		fc_els_close ( els, rc );
+		return;
+	}
+
+	/* Transmit request */
+	if ( ( rc = els->handler->tx_request ( els ) ) != 0 ) {
+		DBGC ( els, FCELS_FMT " could not transmit request: %s\n",
+		       FCELS_ARGS ( els ), strerror ( rc ) );
+		fc_els_close ( els, rc );
+		return;
+	}
+}
+
+/**
+ * Create ELS transaction
+ *
+ * @v port		Fibre Channel port
+ * @v port_id		Local port ID
+ * @v peer_port_id	Peer port ID
+ * @ret els		Fibre Channel ELS transaction, or NULL
+ */
+static struct fc_els * fc_els_create ( struct fc_port *port,
+				       struct fc_port_id *port_id,
+				       struct fc_port_id *peer_port_id ) {
+	struct fc_els *els;
+
+	/* Allocate and initialise structure */
+	els = zalloc ( sizeof ( *els ) );
+	if ( ! els )
+		return NULL;
+	ref_init ( &els->refcnt, fc_els_free );
+	intf_init ( &els->job, &fc_els_job_desc, &els->refcnt );
+	intf_init ( &els->xchg, &fc_els_xchg_desc, &els->refcnt );
+	process_init_stopped ( &els->process, fc_els_step, &els->refcnt );
+	els->port = fc_port_get ( port );
+	memcpy ( &els->port_id, port_id, sizeof ( els->port_id ) );
+	memcpy ( &els->peer_port_id, peer_port_id,
+		 sizeof ( els->peer_port_id ) );
+	return els;
+}
+
+/**
+ * Create ELS request
+ *
+ * @v job		Parent job-control interface
+ * @v port		Fibre Channel port
+ * @v peer_port_id	Peer port ID
+ * @v handler		ELS handler
+ * @ret rc		Return status code
+ */
+int fc_els_request ( struct interface *job, struct fc_port *port,
+		     struct fc_port_id *peer_port_id,
+		     struct fc_els_handler *handler ) {
+	struct fc_els *els;
+
+	/* Allocate and initialise structure */
+	els = fc_els_create ( port, &port->port_id, peer_port_id );
+	if ( ! els )
+		return -ENOMEM;
+	els->handler = handler;
+	els->flags = FC_ELS_REQUEST;
+	process_add ( &els->process );
+
+	/* Attach to parent job interface, mortalise self, and return */
+	intf_plug_plug ( &els->job, job );
+	ref_put ( &els->refcnt );
+	return 0;
+}
+
+/**
+ * Create ELS response
+ *
+ * @v xchg		Exchange interface
+ * @v port		Fibre Channel port
+ * @v port_id		Local port ID
+ * @v peer_port_id	Peer port ID
+ * @ret rc		Return status code
+ */
+static int fc_els_respond ( struct interface *xchg, struct fc_port *port,
+			    struct fc_port_id *port_id,
+			    struct fc_port_id *peer_port_id ) {
+	struct fc_els *els;
+
+	/* Allocate and initialise structure */
+	els = fc_els_create ( port, port_id, peer_port_id );
+	if ( ! els )
+		return -ENOMEM;
+
+	/* Attach to exchange interface, mortalise self, and return */
+	intf_plug_plug ( &els->xchg, xchg );
+	ref_put ( &els->refcnt );
+	return 0;
+}
+
+/** Fibre Channel ELS responder */
+struct fc_responder fc_els_responder __fc_responder = {
+	.type = FC_TYPE_ELS,
+	.respond = fc_els_respond,
+};
+
+/******************************************************************************
+ *
+ * Unknown ELS handler
+ *
+ ******************************************************************************
+ */
+
+/**
+ * Transmit unknown ELS request
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @ret rc		Return status code
+ */
+static int fc_els_unknown_tx_request ( struct fc_els *els __unused ) {
+	return -ENOTSUP;
+}
+
+/**
+ * Transmit unknown ELS response
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @ret rc		Return status code
+ */
+static int fc_els_unknown_tx_response ( struct fc_els *els ) {
+	struct fc_ls_rjt_frame ls_rjt;
+
+	/* Construct LS_RJT */
+	memset ( &ls_rjt, 0, sizeof ( ls_rjt ) );
+	ls_rjt.command = FC_ELS_LS_RJT;
+	ls_rjt.reason = FC_ELS_RJT_UNSUPPORTED;
+
+	/* Transmit LS_RJT */
+	return fc_els_tx ( els, &ls_rjt, sizeof ( ls_rjt ) );
+}
+
+/**
+ * Receive unknown ELS request
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @v data		ELS frame
+ * @v len		Length of ELS frame
+ * @ret rc		Return status code
+ */
+static int fc_els_unknown_rx_request ( struct fc_els *els, const void *data,
+				       size_t len ) {
+
+	DBGC ( els, FCELS_FMT ":\n", FCELS_ARGS ( els ) );
+	DBGC_HDA ( els, 0, data, len );
+	return 0;
+}
+
+/**
+ * Receive unknown ELS response
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @v data		ELS frame
+ * @v len		Length of ELS frame
+ * @ret rc		Return status code
+ */
+static int fc_els_unknown_rx_response ( struct fc_els *els __unused,
+					const void *data __unused,
+					size_t len __unused ) {
+	assert ( 0 );
+	return -EINVAL;
+}
+
+/**
+ * Detect unknown ELS
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @v data		ELS frame
+ * @v len		Length of ELS frame
+ * @ret rc		Return status code
+ */
+static int fc_els_unknown_detect ( struct fc_els *els __unused,
+				   const void *data __unused,
+				   size_t len __unused ) {
+	return -ENOTSUP;
+}
+
+/** Unknown ELS handler */
+struct fc_els_handler fc_els_unknown_handler __fc_els_handler = {
+	.name		= "UNKNOWN",
+	.tx_request	= fc_els_unknown_tx_request,
+	.tx_response	= fc_els_unknown_tx_response,
+	.rx_request	= fc_els_unknown_rx_request,
+	.rx_response	= fc_els_unknown_rx_response,
+	.detect		= fc_els_unknown_detect,
+};
+
+/******************************************************************************
+ *
+ * FLOGI
+ *
+ ******************************************************************************
+ */
+
+/**
+ * Transmit FLOGI
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @ret rc		Return status code
+ */
+static int fc_els_flogi_tx ( struct fc_els *els ) {
+	struct fc_login_frame flogi;
+
+	/* Construct FLOGI */
+	memset ( &flogi, 0, sizeof ( flogi ) );
+	flogi.command = fc_els_tx_command ( els, FC_ELS_FLOGI );
+	flogi.common.version = htons ( FC_LOGIN_VERSION );
+	flogi.common.credit = htons ( FC_LOGIN_DEFAULT_B2B );
+	flogi.common.flags = htons ( FC_LOGIN_CONTINUOUS_OFFSET );
+	flogi.common.mtu = htons ( FC_LOGIN_DEFAULT_MTU );
+	memcpy ( &flogi.port_wwn, &els->port->port_wwn,
+		 sizeof ( flogi.port_wwn ) );
+	memcpy ( &flogi.node_wwn, &els->port->node_wwn,
+		 sizeof ( flogi.node_wwn ) );
+	flogi.class3.flags = htons ( FC_LOGIN_CLASS_VALID |
+				     FC_LOGIN_CLASS_SEQUENTIAL );
+
+	/* Transmit FLOGI */
+	return fc_els_tx ( els, &flogi, sizeof ( flogi ) );
+}
+
+/**
+ * Receive FLOGI
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @v data		ELS frame
+ * @v len		Length of ELS frame
+ * @ret rc		Return status code
+ */
+static int fc_els_flogi_rx ( struct fc_els *els, const void *data,
+			     size_t len ) {
+	const struct fc_login_frame *flogi = data;
+	int has_fabric;
+	int rc;
+
+	/* Sanity check */
+	if ( len < sizeof ( *flogi ) ) {
+		DBGC ( els, FCELS_FMT " received underlength frame:\n",
+		       FCELS_ARGS ( els ) );
+		DBGC_HDA ( els, 0, data, len );
+		return -EINVAL;
+	}
+
+	/* Extract parameters */
+	has_fabric = ( flogi->common.flags & htons ( FC_LOGIN_F_PORT ) );
+	DBGC ( els, FCELS_FMT " has node %s\n", FCELS_ARGS ( els ),
+	       fc_ntoa ( &flogi->node_wwn ) );
+	DBGC ( els, FCELS_FMT " has port %s\n", FCELS_ARGS ( els ),
+	       fc_ntoa ( &flogi->port_wwn ) );
+	if ( has_fabric ) {
+		DBGC ( els, FCELS_FMT " has fabric with local ID %s\n",
+		       FCELS_ARGS ( els ), fc_id_ntoa ( &els->port_id ) );
+	} else {
+		DBGC ( els, FCELS_FMT " has point-to-point link\n",
+		       FCELS_ARGS ( els ) );
+	}
+
+	/* Log in port */
+	if ( ( rc = fc_port_login ( els->port, &els->port_id, &flogi->node_wwn,
+				    &flogi->port_wwn, has_fabric ) ) != 0 ) {
+		DBGC ( els, FCELS_FMT " could not log in port: %s\n",
+		       FCELS_ARGS ( els ), strerror ( rc ) );
+		return rc;
+	}
+
+	return 0;
+}
+
+/**
+ * Detect FLOGI
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @v data		ELS frame
+ * @v len		Length of ELS frame
+ * @ret rc		Return status code
+ */
+static int fc_els_flogi_detect ( struct fc_els *els __unused, const void *data,
+				 size_t len __unused ) {
+	const struct fc_login_frame *flogi = data;
+
+	/* Check for FLOGI */
+	if ( flogi->command != FC_ELS_FLOGI )
+		return -EINVAL;
+
+	return 0;
+}
+
+/** FLOGI ELS handler */
+struct fc_els_handler fc_els_flogi_handler __fc_els_handler = {
+	.name		= "FLOGI",
+	.tx_request	= fc_els_flogi_tx,
+	.tx_response	= fc_els_flogi_tx,
+	.rx_request	= fc_els_flogi_rx,
+	.rx_response	= fc_els_flogi_rx,
+	.detect		= fc_els_flogi_detect,
+};
+
+/**
+ * Create FLOGI request
+ *
+ * @v parent		Parent interface
+ * @v port		Fibre Channel port
+ * @ret rc		Return status code
+ */
+int fc_els_flogi ( struct interface *parent, struct fc_port *port ) {
+
+	return fc_els_request ( parent, port, &fc_f_port_id,
+				&fc_els_flogi_handler );
+}
+
+/******************************************************************************
+ *
+ * PLOGI
+ *
+ ******************************************************************************
+ */
+
+/**
+ * Transmit PLOGI
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @ret rc		Return status code
+ */
+static int fc_els_plogi_tx ( struct fc_els *els ) {
+	struct fc_login_frame plogi;
+
+	/* Construct PLOGI */
+	memset ( &plogi, 0, sizeof ( plogi ) );
+	plogi.command = fc_els_tx_command ( els, FC_ELS_PLOGI );
+	plogi.common.version = htons ( FC_LOGIN_VERSION );
+	plogi.common.credit = htons ( FC_LOGIN_DEFAULT_B2B );
+	plogi.common.flags = htons ( FC_LOGIN_CONTINUOUS_OFFSET );
+	plogi.common.mtu = htons ( FC_LOGIN_DEFAULT_MTU );
+	plogi.common.u.plogi.max_seq = htons ( FC_LOGIN_DEFAULT_MAX_SEQ );
+	plogi.common.u.plogi.rel_offs = htons ( FC_LOGIN_DEFAULT_REL_OFFS );
+	plogi.common.e_d_tov = htonl ( FC_LOGIN_DEFAULT_E_D_TOV );
+	memcpy ( &plogi.port_wwn, &els->port->port_wwn,
+		 sizeof ( plogi.port_wwn ) );
+	memcpy ( &plogi.node_wwn, &els->port->node_wwn,
+		 sizeof ( plogi.node_wwn ) );
+	plogi.class3.flags = htons ( FC_LOGIN_CLASS_VALID |
+				     FC_LOGIN_CLASS_SEQUENTIAL );
+	plogi.class3.mtu = htons ( FC_LOGIN_DEFAULT_MTU );
+	plogi.class3.max_seq = htons ( FC_LOGIN_DEFAULT_MAX_SEQ );
+	plogi.class3.max_seq_per_xchg = 1;
+
+	/* Transmit PLOGI */
+	return fc_els_tx ( els, &plogi, sizeof ( plogi ) );
+}
+
+/**
+ * Receive PLOGI
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @v data		ELS frame
+ * @v len		Length of ELS frame
+ * @ret rc		Return status code
+ */
+static int fc_els_plogi_rx ( struct fc_els *els, const void *data,
+			     size_t len ) {
+	const struct fc_login_frame *plogi = data;
+	struct fc_peer *peer;
+	int rc;
+
+	/* Sanity checks */
+	if ( len < sizeof ( *plogi ) ) {
+		DBGC ( els, FCELS_FMT " received underlength frame:\n",
+		       FCELS_ARGS ( els ) );
+		DBGC_HDA ( els, 0, data, len );
+		rc = -EINVAL;
+		goto err_sanity;
+	}
+	if ( ! fc_link_ok ( &els->port->link ) ) {
+		DBGC ( els, FCELS_FMT " received while port link is down\n",
+		       FCELS_ARGS ( els ) );
+		rc = -EINVAL;
+		goto err_sanity;
+	}
+
+	/* Extract parameters */
+	DBGC ( els, FCELS_FMT " has node %s\n", FCELS_ARGS ( els ),
+	       fc_ntoa ( &plogi->node_wwn ) );
+	DBGC ( els, FCELS_FMT " has port %s as %s\n",
+	       FCELS_ARGS ( els ), fc_ntoa ( &plogi->port_wwn ),
+	       fc_id_ntoa ( &els->peer_port_id ) );
+
+	/* Get peer */
+	peer = fc_peer_get_wwn ( &plogi->node_wwn );
+	if ( ! peer ) {
+		DBGC ( els, FCELS_FMT " could not create peer\n",
+		       FCELS_ARGS ( els ) );
+		rc = -ENOMEM;
+		goto err_peer_get_wwn;
+	}
+
+	/* Record login */
+	if ( ( rc = fc_peer_login ( peer, els->port,
+				    &els->peer_port_id ) ) != 0 ) {
+		DBGC ( els, FCELS_FMT " could not log in peer: %s\n",
+		       FCELS_ARGS ( els ), strerror ( rc ) );
+		goto err_login;
+	}
+
+	/* Drop temporary reference to peer */
+	fc_peer_put ( peer );
+
+	return 0;
+
+ err_login:
+	fc_peer_put ( peer );
+ err_peer_get_wwn:
+ err_sanity:
+	return rc;
+}
+
+/**
+ * Detect PLOGI
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @v data		ELS frame
+ * @v len		Length of ELS frame
+ * @ret rc		Return status code
+ */
+static int fc_els_plogi_detect ( struct fc_els *els __unused, const void *data,
+				 size_t len __unused ) {
+	const struct fc_login_frame *plogi = data;
+
+	/* Check for PLOGI */
+	if ( plogi->command != FC_ELS_PLOGI )
+		return -EINVAL;
+
+	return 0;
+}
+
+/** PLOGI ELS handler */
+struct fc_els_handler fc_els_plogi_handler __fc_els_handler = {
+	.name		= "PLOGI",
+	.tx_request	= fc_els_plogi_tx,
+	.tx_response	= fc_els_plogi_tx,
+	.rx_request	= fc_els_plogi_rx,
+	.rx_response	= fc_els_plogi_rx,
+	.detect		= fc_els_plogi_detect,
+};
+
+/**
+ * Create PLOGI request
+ *
+ * @v parent		Parent interface
+ * @v port		Fibre Channel port
+ * @v peer_port_id	Peer port ID
+ * @ret rc		Return status code
+ */
+int fc_els_plogi ( struct interface *parent, struct fc_port *port,
+		   struct fc_port_id *peer_port_id ) {
+
+	return fc_els_request ( parent, port, peer_port_id,
+				&fc_els_plogi_handler );
+}
+
+/******************************************************************************
+ *
+ * LOGO
+ *
+ ******************************************************************************
+ */
+
+/**
+ * Transmit LOGO request
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @ret rc		Return status code
+ */
+static int fc_els_logo_tx_request ( struct fc_els *els ) {
+	struct fc_logout_request_frame logo;
+
+	/* Construct LOGO */
+	memset ( &logo, 0, sizeof ( logo ) );
+	logo.command = FC_ELS_LOGO;
+	memcpy ( &logo.port_id, &els->port->port_id, sizeof ( logo.port_id ) );
+	memcpy ( &logo.port_wwn, &els->port->port_wwn,
+		 sizeof ( logo.port_wwn ) );
+
+	/* Transmit LOGO */
+	return fc_els_tx ( els, &logo, sizeof ( logo ) );
+}
+
+/**
+ * Transmit LOGO response
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @ret rc		Return status code
+ */
+static int fc_els_logo_tx_response ( struct fc_els *els ) {
+	struct fc_logout_response_frame logo;
+
+	/* Construct LOGO */
+	memset ( &logo, 0, sizeof ( logo ) );
+	logo.command = FC_ELS_LS_ACC;
+
+	/* Transmit LOGO */
+	return fc_els_tx ( els, &logo, sizeof ( logo ) );
+}
+
+/**
+ * Log out individual peer or whole port as applicable
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @v port_id		Peer port ID
+ */
+static void fc_els_logo_logout ( struct fc_els *els,
+				 const struct fc_port_id *peer_port_id ) {
+	struct fc_peer *peer;
+
+	if ( ( memcmp ( peer_port_id, &fc_f_port_id,
+			sizeof ( *peer_port_id ) ) == 0 ) ||
+	     ( memcmp ( peer_port_id, &els->port->port_id,
+			sizeof ( *peer_port_id ) ) == 0 ) ) {
+		fc_port_logout ( els->port, 0 );
+	} else {
+		peer = fc_peer_get_port_id ( els->port, peer_port_id );
+		if ( peer ) {
+			fc_peer_logout ( peer, 0 );
+			fc_peer_put ( peer );
+		}
+	}
+}
+
+/**
+ * Receive LOGO request
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @v data		ELS frame
+ * @v len		Length of ELS frame
+ * @ret rc		Return status code
+ */
+static int fc_els_logo_rx_request ( struct fc_els *els, const void *data,
+				    size_t len ) {
+	const struct fc_logout_request_frame *logo = data;
+
+	/* Sanity check */
+	if ( len < sizeof ( *logo ) ) {
+		DBGC ( els, FCELS_FMT " received underlength frame:\n",
+		       FCELS_ARGS ( els ) );
+		DBGC_HDA ( els, 0, data, len );
+		return -EINVAL;
+	}
+
+	DBGC ( els, FCELS_FMT " has port %s as %s\n", FCELS_ARGS ( els ),
+	       fc_ntoa ( &logo->port_wwn ), fc_id_ntoa ( &logo->port_id ) );
+
+	/* Log out individual peer or whole port as applicable */
+	fc_els_logo_logout ( els, &logo->port_id );
+
+	return 0;
+}
+
+/**
+ * Receive LOGO response
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @v data		ELS frame
+ * @v len		Length of ELS frame
+ * @ret rc		Return status code
+ */
+static int fc_els_logo_rx_response ( struct fc_els *els,
+				     const void *data __unused,
+				     size_t len __unused ) {
+
+	/* Log out individual peer or whole port as applicable */
+	fc_els_logo_logout ( els, &els->port_id );
+
+	return 0;
+}
+
+/**
+ * Detect LOGO
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @v data		ELS frame
+ * @v len		Length of ELS frame
+ * @ret rc		Return status code
+ */
+static int fc_els_logo_detect ( struct fc_els *els __unused, const void *data,
+				size_t len __unused ) {
+	const struct fc_logout_request_frame *logo = data;
+
+	/* Check for LOGO */
+	if ( logo->command != FC_ELS_LOGO )
+		return -EINVAL;
+
+	return 0;
+}
+
+/** LOGO ELS handler */
+struct fc_els_handler fc_els_logo_handler __fc_els_handler = {
+	.name		= "LOGO",
+	.tx_request	= fc_els_logo_tx_request,
+	.tx_response	= fc_els_logo_tx_response,
+	.rx_request	= fc_els_logo_rx_request,
+	.rx_response	= fc_els_logo_rx_response,
+	.detect		= fc_els_logo_detect,
+};
+
+/**
+ * Create LOGO request
+ *
+ * @v parent		Parent interface
+ * @v port		Fibre Channel port
+ * @v peer_port_id	Peer port ID
+ * @ret rc		Return status code
+ */
+int fc_els_logo ( struct interface *parent, struct fc_port *port,
+		  struct fc_port_id *peer_port_id ) {
+
+	return fc_els_request ( parent, port, peer_port_id,
+				&fc_els_logo_handler );
+}
+
+/******************************************************************************
+ *
+ * PRLI
+ *
+ ******************************************************************************
+ */
+
+/**
+ * Find PRLI descriptor
+ *
+ * @v type		Upper-layer protocol type
+ * @ret descriptor	PRLI descriptor, or NULL
+ */
+static struct fc_els_prli_descriptor *
+fc_els_prli_descriptor ( unsigned int type ) {
+	struct fc_els_prli_descriptor *descriptor;
+
+	for_each_table_entry ( descriptor, FC_ELS_PRLI_DESCRIPTORS ) {
+		if ( descriptor->type == type )
+			return descriptor;
+	}
+	return NULL;
+}
+
+/**
+ * Transmit PRLI
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @v descriptor	ELS PRLI descriptor
+ * @v param		Service parameters
+ * @ret rc		Return status code
+ */
+int fc_els_prli_tx ( struct fc_els *els,
+		     struct fc_els_prli_descriptor *descriptor, void *param ) {
+	struct {
+		struct fc_prli_frame frame;
+		uint8_t param[descriptor->param_len];
+	} __attribute__ (( packed )) prli;
+	struct fc_ulp *ulp;
+	int rc;
+
+	/* Get ULP */
+	ulp = fc_ulp_get_port_id_type ( els->port, &els->peer_port_id,
+					descriptor->type );
+	if ( ! ulp ) {
+		rc = -ENOMEM;
+		goto err_get_port_id_type;
+	}
+
+	/* Build frame for transmission */
+	memset ( &prli, 0, sizeof ( prli ) );
+	prli.frame.command = fc_els_tx_command ( els, FC_ELS_PRLI );
+	prli.frame.page_len =
+		( sizeof ( prli.frame.page ) + sizeof ( prli.param ) );
+	prli.frame.len = htons ( sizeof ( prli ) );
+	prli.frame.page.type = descriptor->type;
+	if ( fc_els_is_request ( els ) ) {
+		prli.frame.page.flags |= htons ( FC_PRLI_ESTABLISH );
+	} else if ( fc_link_ok ( &ulp->link ) ) {
+		prli.frame.page.flags |= htons ( FC_PRLI_ESTABLISH |
+						    FC_PRLI_RESPONSE_SUCCESS );
+	}
+	memcpy ( &prli.param, param, sizeof ( prli.param ) );
+
+	/* Transmit frame */
+	if ( ( rc = fc_els_tx ( els, &prli, sizeof ( prli ) ) ) != 0 )
+		goto err_tx;
+
+	/* Drop temporary reference to ULP */
+	fc_ulp_put ( ulp );
+
+	return 0;
+
+ err_tx:
+	fc_ulp_put ( ulp );
+ err_get_port_id_type:
+	return rc;
+}
+
+/**
+ * Receive PRLI
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @v descriptor	ELS PRLI descriptor
+ * @v frame		ELS frame
+ * @v len		Length of ELS frame
+ * @ret rc		Return status code
+ */
+int fc_els_prli_rx ( struct fc_els *els,
+		     struct fc_els_prli_descriptor *descriptor,
+		     const void *data, size_t len ) {
+	const struct {
+		struct fc_prli_frame frame;
+		uint8_t param[descriptor->param_len];
+	} __attribute__ (( packed )) *prli = data;
+	struct fc_ulp *ulp;
+	int rc;
+
+	/* Sanity check */
+	if ( len < sizeof ( *prli ) ) {
+		DBGC ( els, FCELS_FMT " received underlength frame:\n",
+		       FCELS_ARGS ( els ) );
+		DBGC_HDA ( els, 0, data, len );
+		rc = -EINVAL;
+		goto err_sanity;
+	}
+
+	DBGC ( els, FCELS_FMT " has parameters:\n", FCELS_ARGS ( els ) );
+	DBGC_HDA ( els, 0, prli->param, sizeof ( prli->param ) );
+
+	/* Get ULP */
+	ulp = fc_ulp_get_port_id_type ( els->port, &els->peer_port_id,
+					descriptor->type );
+	if ( ! ulp ) {
+		rc = -ENOMEM;
+		goto err_get_port_id_type;
+	}
+
+	/* Sanity check */
+	if ( ! fc_link_ok ( &ulp->peer->link ) ) {
+		DBGC ( els, FCELS_FMT " received while peer link is down\n",
+		       FCELS_ARGS ( els ) );
+		rc = -EINVAL;
+		goto err_link;
+	}
+
+	/* Log in ULP, if applicable */
+	if ( prli->frame.page.flags & htons ( FC_PRLI_ESTABLISH ) ) {
+		if ( ( rc = fc_ulp_login ( ulp, prli->param,
+					   sizeof ( prli->param ),
+					   fc_els_is_request ( els ) ) ) != 0 ){
+			DBGC ( els, FCELS_FMT " could not log in ULP: %s\n",
+			       FCELS_ARGS ( els ), strerror ( rc ) );
+			goto err_login;
+		}
+	} else {
+		if ( fc_els_is_request ( els ) ) {
+			fc_ulp_logout ( ulp, -EACCES );
+		} else {
+			/* This is just an information-gathering PRLI; do not
+			 * log in or out
+			 */
+		}
+	}
+
+	/* Drop temporary reference to ULP */
+	fc_ulp_put ( ulp );
+
+	return 0;
+
+ err_login:
+ err_link:
+	fc_ulp_put ( ulp );
+ err_get_port_id_type:
+ err_sanity:
+	return rc;
+}
+
+/**
+ * Detect PRLI
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @v descriptor	ELS PRLI descriptor
+ * @v data		ELS frame
+ * @v len		Length of ELS frame
+ * @ret rc		Return status code
+ */
+int fc_els_prli_detect ( struct fc_els *els __unused,
+			 struct fc_els_prli_descriptor *descriptor,
+			 const void *data, size_t len ) {
+	const struct {
+		struct fc_prli_frame frame;
+		uint8_t param[descriptor->param_len];
+	} __attribute__ (( packed )) *prli = data;
+
+	/* Check for PRLI */
+	if ( prli->frame.command != FC_ELS_PRLI )
+		return -EINVAL;
+
+	/* Check for sufficient length to contain service parameter page */
+	if ( len < sizeof ( *prli ) )
+		return -EINVAL;
+
+	/* Check for upper-layer protocol type */
+	if ( prli->frame.page.type != descriptor->type )
+		return -EINVAL;
+
+	return 0;
+}
+
+/**
+ * Create PRLI request
+ *
+ * @v parent		Parent interface
+ * @v port		Fibre Channel port
+ * @v peer_port_id	Peer port ID
+ * @v type		Upper-layer protocol type
+ * @ret rc		Return status code
+ */
+int fc_els_prli ( struct interface *parent, struct fc_port *port,
+		  struct fc_port_id *peer_port_id, unsigned int type ) {
+	struct fc_els_prli_descriptor *descriptor;
+
+	/* Find a PRLI descriptor */
+	descriptor = fc_els_prli_descriptor ( type );
+	if ( ! descriptor )
+		return -ENOTSUP;
+
+	return fc_els_request ( parent, port, peer_port_id,
+				descriptor->handler );
+}
+
+/******************************************************************************
+ *
+ * RTV
+ *
+ ******************************************************************************
+ */
+
+/**
+ * Transmit RTV response
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @ret rc		Return status code
+ */
+static int fc_els_rtv_tx_response ( struct fc_els *els ) {
+	struct fc_rtv_response_frame rtv;
+
+	/* Construct RTV */
+	memset ( &rtv, 0, sizeof ( rtv ) );
+	rtv.command = FC_ELS_LS_ACC;
+	rtv.e_d_tov = htonl ( FC_LOGIN_DEFAULT_E_D_TOV );
+
+	/* Transmit RTV */
+	return fc_els_tx ( els, &rtv, sizeof ( rtv ) );
+}
+
+/**
+ * Receive RTV request
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @v data		ELS frame
+ * @v len		Length of ELS frame
+ * @ret rc		Return status code
+ */
+static int fc_els_rtv_rx_request ( struct fc_els *els,
+				   const void *data __unused,
+				   size_t len __unused ) {
+
+	DBGC ( els, FCELS_FMT "\n", FCELS_ARGS ( els ) );
+
+	/* Nothing to do */
+	return 0;
+}
+
+/**
+ * Detect RTV
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @v data		ELS frame
+ * @v len		Length of ELS frame
+ * @ret rc		Return status code
+ */
+static int fc_els_rtv_detect ( struct fc_els *els __unused, const void *data,
+			       size_t len __unused ) {
+	const struct fc_rtv_request_frame *rtv = data;
+
+	/* Check for RTV */
+	if ( rtv->command != FC_ELS_RTV )
+		return -EINVAL;
+
+	return 0;
+}
+
+/** RTV ELS handler */
+struct fc_els_handler fc_els_rtv_handler __fc_els_handler = {
+	.name		= "RTV",
+	.tx_request	= fc_els_unknown_tx_request,
+	.tx_response	= fc_els_rtv_tx_response,
+	.rx_request	= fc_els_rtv_rx_request,
+	.rx_response	= fc_els_unknown_rx_response,
+	.detect		= fc_els_rtv_detect,
+};