[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>

4 files changed, 909 insertions, 0 deletions

diff --git a/src/include/ipxe/errfile.h b/src/include/ipxe/errfile.h
index d78f28229..d530d9029 100644
--- a/src/include/ipxe/errfile.h
+++ b/src/include/ipxe/errfile.h
@@ -184,6 +184,8 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #define ERRFILE_wpa_tkip		( ERRFILE_NET | 0x00280000 )
 #define ERRFILE_wpa_ccmp		( ERRFILE_NET | 0x00290000 )
 #define ERRFILE_eth_slow		( ERRFILE_NET | 0x002a0000 )
+#define ERRFILE_fc			( ERRFILE_NET | 0x002b0000 )
+#define ERRFILE_fcels			( ERRFILE_NET | 0x002c0000 )
 
 #define ERRFILE_image		      ( ERRFILE_IMAGE | 0x00000000 )
 #define ERRFILE_elf		      ( ERRFILE_IMAGE | 0x00010000 )
diff --git a/src/include/ipxe/fc.h b/src/include/ipxe/fc.h
new file mode 100644
index 000000000..5d73068f2
--- /dev/null
+++ b/src/include/ipxe/fc.h
@@ -0,0 +1,439 @@
+#ifndef _IPXE_FC_H
+#define _IPXE_FC_H
+
+/**
+ * @file
+ *
+ * Fibre Channel
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdint.h>
+#include <ipxe/refcnt.h>
+#include <ipxe/list.h>
+#include <ipxe/tables.h>
+#include <ipxe/interface.h>
+#include <ipxe/retry.h>
+
+/******************************************************************************
+ *
+ * Fibre Channel Names and identifiers
+ *
+ ******************************************************************************
+ */
+
+/** A Fibre Channel name */
+struct fc_name {
+	uint8_t bytes[8];
+} __attribute__ (( packed ));
+
+/** Length of Fibre Channel name text */
+#define FC_NAME_STRLEN 23 /* "xx:xx:xx:xx:xx:xx:xx:xx" */
+
+/** A Fibre Channel port identifier */
+struct fc_port_id {
+	uint8_t bytes[3];
+} __attribute__ (( packed ));
+
+/** Length of Fibre Channel port identifier next */
+#define FC_PORT_ID_STRLEN 9 /* "xx.xx.xx" */
+
+extern struct fc_port_id fc_empty_port_id;
+extern struct fc_port_id fc_f_port_id;
+extern struct fc_port_id fc_ptp_low_port_id;
+extern struct fc_port_id fc_ptp_high_port_id;
+
+extern const char * fc_id_ntoa ( const struct fc_port_id *id );
+extern int fc_id_aton ( const char *id_text, struct fc_port_id *id );
+extern const char * fc_ntoa ( const struct fc_name *wwn );
+extern int fc_aton ( const char *wwn_text, struct fc_name *wwn );
+
+/******************************************************************************
+ *
+ * Fibre Channel link state
+ *
+ ******************************************************************************
+ */
+
+/** Delay between failed link-up attempts */
+#define FC_LINK_RETRY_DELAY ( 2 * TICKS_PER_SEC )
+
+/** A Fibre Channel link state nonitor */
+struct fc_link_state {
+	/** Retry timer */
+	struct retry_timer timer;
+	/** Link state */
+	int rc;
+	/** Examine link state
+	 *
+	 * @v link		Fibre Channel link state monitor
+	 */
+	void ( * examine ) ( struct fc_link_state *link );
+};
+
+/**
+ * Check Fibre Channel link state
+ *
+ * @v link		Fibre Channel link state monitor
+ * @ret link_up		Link is up
+ */
+static inline __attribute__ (( always_inline )) int
+fc_link_ok ( struct fc_link_state *link ) {
+	return ( link->rc == 0 );
+}
+
+/******************************************************************************
+ *
+ * Fibre Channel packet formats and exchanges
+ *
+ ******************************************************************************
+ */
+
+/** A Fibre Channel Frame Header */
+struct fc_frame_header {
+	/** Routing control
+	 *
+	 * This is the bitwise OR of one @c fc_r_ctl_routing value and
+	 * one @c fc_r_ctl_info value.
+	 */
+	uint8_t r_ctl;
+	/** Destination ID */
+	struct fc_port_id d_id;
+	/** Class-specific control / Priority */
+	uint8_t cs_ctl_prio;
+	/** Source ID */
+	struct fc_port_id s_id;
+	/** Data structure type */
+	uint8_t type;
+	/** Frame control - exchange and sequence */
+	uint8_t f_ctl_es;
+	/** Frame control - acknowledgements  */
+	uint8_t f_ctl_ack;
+	/** Frame control - miscellaneous */
+	uint8_t f_ctl_misc;
+	/** Sequence ID */
+	uint8_t seq_id;
+	/** Data field control */
+	uint8_t df_ctl;
+	/** Sequence count */
+	uint16_t seq_cnt;
+	/** Originator exchange ID */
+	uint16_t ox_id;
+	/** Responder exchange ID */
+	uint16_t rx_id;
+	/** Parameter
+	 *
+	 * Contains the relative offset when @c FC_F_CTL_MISC_REL_OFF
+	 * is set.
+	 */
+	uint32_t parameter;
+} __attribute__ (( packed ));
+
+/** Fibre Channel Routing Control Routing */
+enum fc_r_ctl_routing {
+	FC_R_CTL_DATA = 0x00,		/**< Device Data */
+	FC_R_CTL_ELS = 0x20,		/**< Extended Link Services */
+	FC_R_CTL_FC4_LINK = 0x30,	/**< FC-4 Link Data */
+	FC_R_CTL_VIDEO = 0x40,		/**< Video Data */
+	FC_R_CTL_EH = 0x50,		/**< Extended Headers */
+	FC_R_CTL_BLS = 0x80,		/**< Basic Link Services */
+	FC_R_CTL_LINK_CTRL = 0xc0,	/**< Link Control */
+	FC_R_CTL_EXT_ROUTE = 0xf0,	/**< Extended Routing */
+};
+
+/** Fibre Channel Routing Control Routing mask */
+#define FC_R_CTL_ROUTING_MASK 0xf0
+
+/** Fibre Channel Routing Control Information */
+enum fc_r_ctl_info {
+	FC_R_CTL_UNCAT = 0x00,		/**< Uncategorized */
+	FC_R_CTL_SOL_DATA = 0x01,	/**< Solicited Data */
+	FC_R_CTL_UNSOL_CTRL = 0x02,	/**< Unsolicited Control */
+	FC_R_CTL_SOL_CTRL = 0x03,	/**< Solicited Control */
+	FC_R_CTL_UNSOL_DATA = 0x04,	/**< Unsolicited Data */
+	FC_R_CTL_DATA_DESC = 0x05,	/**< Data Descriptor */
+	FC_R_CTL_UNSOL_CMD = 0x06,	/**< Unsolicited Command */
+	FC_R_CTL_CMD_STAT = 0x07,	/**< Command Status */
+};
+
+/** Fibre Channel Routing Control Information mask */
+#define FC_R_CTL_INFO_MASK 0x07
+
+/** Fibre Channel Data Structure Type */
+enum fc_type {
+	FC_TYPE_BLS = 0x00,		/**< Basic Link Service */
+	FC_TYPE_ELS = 0x01,		/**< Extended Link Service */
+	FC_TYPE_FCP = 0x08,		/**< Fibre Channel Protocol */
+};
+
+/** Fibre Channel Frame Control - Exchange and Sequence */
+enum fc_f_ctl_es {
+	FC_F_CTL_ES_RESPONDER = 0x80,	/**< Responder of Exchange */
+	FC_F_CTL_ES_RECIPIENT = 0x40,	/**< Sequence Recipient */
+	FC_F_CTL_ES_FIRST = 0x20,	/**< First Sequence of Exchange */
+	FC_F_CTL_ES_LAST = 0x10,	/**< Last Sequence of Exchange */
+	FC_F_CTL_ES_END = 0x08,		/**< Last Data Frame of Sequence */
+	FC_F_CTL_ES_TRANSFER = 0x01,	/**< Transfer Sequence Initiative */
+};
+
+/** Fibre Channel Frame Control - Miscellaneous */
+enum fc_f_ctl_misc {
+	FC_F_CTL_MISC_REL_OFF = 0x08,	/**< Relative Offset Present */
+};
+
+/** Responder exchange identifier used before first response */
+#define FC_RX_ID_UNKNOWN 0xffff
+
+struct fc_port;
+
+extern int fc_xchg_originate ( struct interface *parent, struct fc_port *port,
+			       struct fc_port_id *peer_port_id,
+			       unsigned int type );
+
+/** A Fibre Channel responder */
+struct fc_responder {
+	/** Type */
+	unsigned int type;
+	/** Respond to exchange
+	 *
+	 * @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
+	 */
+	int ( * respond ) ( struct interface *xchg, struct fc_port *port,
+			    struct fc_port_id *port_id,
+			    struct fc_port_id *peer_port_id );
+};
+
+/** Fibre Channel responder table */
+#define FC_RESPONDERS __table ( struct fc_responder, "fc_responders" )
+
+/** Declare a Fibre Channel responder */
+#define __fc_responder __table_entry ( FC_RESPONDERS, 01 )
+
+/******************************************************************************
+ *
+ * Fibre Channel ports
+ *
+ ******************************************************************************
+ */
+
+/** A Fibre Channel port */
+struct fc_port {
+	/** Reference count */
+	struct refcnt refcnt;
+	/** List of all ports */
+	struct list_head list;
+	/** Name of this port */
+	char name[8];
+
+	/** Transport interface */
+	struct interface transport;
+	/** Node name */
+	struct fc_name node_wwn;
+	/** Port name */
+	struct fc_name port_wwn;
+	/** Local port ID */
+	struct fc_port_id port_id;
+	/** Flags */
+	unsigned int flags;
+
+	/** Link state monitor */
+	struct fc_link_state link;
+	/** FLOGI interface */
+	struct interface flogi;
+	/** Link node name */
+	struct fc_name link_node_wwn;
+	/** Link port name */
+	struct fc_name link_port_wwn;
+	/** Link port ID (for point-to-point links only) */
+	struct fc_port_id ptp_link_port_id;
+
+	/** List of active exchanges */
+	struct list_head xchgs;
+};
+
+/** Fibre Channel port flags */
+enum fc_port_flags {
+	/** Port is attached to a fabric */
+	FC_PORT_HAS_FABRIC = 0x0001,
+};
+
+/**
+ * Get reference to Fibre Channel port
+ *
+ * @v port		Fibre Channel port
+ * @ret port		Fibre Channel port
+ */
+static inline __attribute__ (( always_inline )) struct fc_port *
+fc_port_get ( struct fc_port *port ) {
+	ref_get ( &port->refcnt );
+	return port;
+}
+
+/**
+ * Drop reference to Fibre Channel port
+ *
+ * @v port		Fibre Channel port
+ */
+static inline __attribute__ (( always_inline )) void
+fc_port_put ( struct fc_port *port ) {
+	ref_put ( &port->refcnt );
+}
+
+extern struct list_head fc_ports;
+
+extern 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 );
+extern void fc_port_logout ( struct fc_port *port, int rc );
+extern int fc_port_open ( struct interface *transport,
+			  const struct fc_name *node_wwn,
+			  const struct fc_name *port_wwn );
+extern struct fc_port * fc_port_find ( const char *name );
+
+/******************************************************************************
+ *
+ * Fibre Channel peers
+ *
+ ******************************************************************************
+ */
+
+/** A Fibre Channel peer */
+struct fc_peer {
+	/** Reference count */
+	struct refcnt refcnt;
+	/** List of all peers */
+	struct list_head list;
+
+	/** Node name */
+	struct fc_name node_wwn;
+
+	/** Link state monitor */
+	struct fc_link_state link;
+	/** PLOGI interface */
+	struct interface plogi;
+	/** Fibre Channel port, if known */
+	struct fc_port *port;
+	/** Peer port ID, if known */
+	struct fc_port_id port_id;
+
+	/** List of upper-layer protocols */
+	struct list_head ulps;
+	/** Active usage count */
+	unsigned int usage;
+};
+
+/**
+ * Get reference to Fibre Channel peer
+ *
+ * @v peer		Fibre Channel peer
+ * @ret peer		Fibre Channel peer
+ */
+static inline __attribute__ (( always_inline )) struct fc_peer *
+fc_peer_get ( struct fc_peer *peer ) {
+	ref_get ( &peer->refcnt );
+	return peer;
+}
+
+/**
+ * Drop reference to Fibre Channel peer
+ *
+ * @v peer		Fibre Channel peer
+ */
+static inline __attribute__ (( always_inline )) void
+fc_peer_put ( struct fc_peer *peer ) {
+	ref_put ( &peer->refcnt );
+}
+
+extern struct list_head fc_peers;
+
+extern struct fc_peer * fc_peer_get_wwn ( const struct fc_name *node_wwn );
+extern struct fc_peer *
+fc_peer_get_port_id ( struct fc_port *port,
+		      const struct fc_port_id *peer_port_id );
+extern int fc_peer_login ( struct fc_peer *peer,
+			   struct fc_port *port,
+			   struct fc_port_id *port_id );
+extern void fc_peer_logout ( struct fc_peer *peer, int rc );
+
+/******************************************************************************
+ *
+ * Fibre Channel upper-layer protocols
+ *
+ ******************************************************************************
+ */
+
+/** A Fibre Channel upper-layer protocol */
+struct fc_ulp {
+	/** Reference count */
+	struct refcnt refcnt;
+	/** Fibre Channel peer */
+	struct fc_peer *peer;
+	/** List of upper-layer protocols */
+	struct list_head list;
+
+	/** Type */
+	unsigned int type;
+	/** Flags */
+	unsigned int flags;
+
+	/** Link state monitor */
+	struct fc_link_state link;
+	/** PRLI interface */
+	struct interface prli;
+	/** Service parameters, if any */
+	void *param;
+	/** Service parameter length */
+	size_t param_len;
+
+	/** Active usage count */
+	unsigned int usage;
+};
+
+/** Fibre Channel upper-layer protocol flags */
+enum fc_ulp_flags {
+	/** A login originated by us has succeeded */
+	FC_ULP_ORIGINATED_LOGIN_OK = 0x0001,
+};
+
+/**
+ * Get reference to Fibre Channel upper-layer protocol
+ *
+ * @v ulp		Fibre Channel upper-layer protocol
+ * @ret ulp		Fibre Channel upper-layer protocol
+ */
+static inline __attribute__ (( always_inline )) struct fc_ulp *
+fc_ulp_get ( struct fc_ulp *ulp ) {
+	ref_get ( &ulp->refcnt );
+	return ulp;
+}
+
+/**
+ * Drop reference to Fibre Channel upper-layer protocol
+ *
+ * @v ulp		Fibre Channel upper-layer protocol
+ */
+static inline __attribute__ (( always_inline )) void
+fc_ulp_put ( struct fc_ulp *ulp ) {
+	ref_put ( &ulp->refcnt );
+}
+
+extern struct fc_ulp * fc_ulp_get_wwn_type ( const struct fc_name *node_wwn,
+					     unsigned int type );
+extern struct fc_ulp *
+fc_ulp_get_port_id_type ( struct fc_port *port,
+			  const struct fc_port_id *peer_port_id,
+			  unsigned int type );
+extern void fc_ulp_increment ( struct fc_ulp *ulp );
+extern void fc_ulp_decrement ( struct fc_ulp *ulp );
+extern int fc_ulp_login ( struct fc_ulp *ulp, const void *param,
+			  size_t param_len, int originated );
+extern void fc_ulp_logout ( struct fc_ulp *ulp, int rc );
+
+#endif /* _IPXE_FC_H */
diff --git a/src/include/ipxe/fcels.h b/src/include/ipxe/fcels.h
new file mode 100644
index 000000000..b35cb04c7
--- /dev/null
+++ b/src/include/ipxe/fcels.h
@@ -0,0 +1,452 @@
+#ifndef _IPXE_FCELS_H
+#define _IPXE_FCELS_H
+
+/**
+ * @file
+ *
+ * Fibre Channel Extended Link Services
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdint.h>
+#include <ipxe/fc.h>
+#include <ipxe/tables.h>
+#include <ipxe/refcnt.h>
+#include <ipxe/list.h>
+#include <ipxe/process.h>
+#include <ipxe/interface.h>
+
+/** Fibre Channel ELS frame common parameters */
+struct fc_els_frame_common {
+	/** ELS command code */
+	uint8_t command;
+	/** Reserved */
+	uint8_t reserved[3];
+} __attribute__ (( packed ));
+
+/** Fibre Channel ELS command codes */
+enum fc_els_command_code {
+	FC_ELS_LS_RJT = 0x01,		/**< Link Service Reject */
+	FC_ELS_LS_ACC = 0x02,		/**< Link Service Accept */
+	FC_ELS_PLOGI = 0x03,		/**< Port Login */
+	FC_ELS_FLOGI = 0x04,		/**< Fabric Login */
+	FC_ELS_LOGO = 0x05,		/**< Logout */
+	FC_ELS_RTV = 0x0e,		/**< Read Timeout Value */
+	FC_ELS_PRLI = 0x20,		/**< Process Login */
+	FC_ELS_PRLO = 0x21,		/**< Process Logout */
+};
+
+/** A Fibre Channel LS_RJT frame */
+struct fc_ls_rjt_frame {
+	/** ELS command code */
+	uint8_t command;
+	/** Reserved */
+	uint8_t reserved[4];
+	/** Reason code */
+	uint8_t reason;
+	/** Reason code explanation */
+	uint8_t explanation;
+	/** Vendor unique */
+	uint8_t vendor;
+} __attribute__ (( packed ));
+
+/** Fibre Channel ELS rejection reason codes */
+enum fc_els_reject_reason {
+	/** Invalid ELS command code */
+	FC_ELS_RJT_INVALID_COMMAND = 0x01,
+	/** Logical error */
+	FC_ELS_RJT_ILLOGICAL = 0x03,
+	/** Logical busy */
+	FC_ELS_RJT_BUSY = 0x05,
+	/** Protocol error */
+	FC_ELS_RJT_PROTOCOL = 0x07,
+	/** Unable to perform command request */
+	FC_ELS_RJT_UNABLE = 0x09,
+	/** Command not supported */
+	FC_ELS_RJT_UNSUPPORTED = 0x0b,
+	/** Command already in progress */
+	FC_ELS_RJT_IN_PROGRESS = 0x0e,
+};
+
+/** Fibre Channel "common" service parameters */
+struct fc_login_common {
+	/** Login version */
+	uint16_t version;
+	/** Buffer-to-buffer credit */
+	uint16_t credit;
+	/** Flags */
+	uint16_t flags;
+	/** Receive size */
+	uint16_t mtu;
+	/** "Common"?! */
+	union {
+		struct {
+			/** Maximum number of concurrent sequences */
+			uint16_t max_seq;
+			/** Relative offset by info category */
+			uint16_t rel_offs;
+		} plogi;
+		struct {
+			/** Resource allocation timeout value */
+			uint32_t r_a_tov;
+		} flogi;
+	} u;
+	/** Error detection timeout value */
+	uint32_t e_d_tov;
+} __attribute__ (( packed ));
+
+/** Fibre Channel default login version */
+#define FC_LOGIN_VERSION 0x2020
+
+/** Fibre Channel default buffer-to-buffer credit */
+#define FC_LOGIN_DEFAULT_B2B 10
+
+/** Continuously increasing relative offset */
+#define FC_LOGIN_CONTINUOUS_OFFSET 0x8000
+
+/** Clean address */
+#define FC_LOGIN_CLEAN 0x8000
+
+/** Multiple N_Port_ID support */
+#define FC_LOGIN_MULTI_N 0x8000
+
+/** Random relative offset */
+#define FC_LOGIN_RANDOM_OFFSET 0x4000
+
+/** Virtual fabrics */
+#define FC_LOGIN_VIRTUAL 0x4000
+
+/** Vendor version level */
+#define FC_LOGIN_VENDOR 0x2000
+
+/** Multiple N_Port_ID support */
+#define FC_LOGIN_MULTI_F 0x2000
+
+/** Forwarder port */
+#define FC_LOGIN_F_PORT 0x1000
+
+/** Alternative credit management */
+#define FC_LOGIN_ALT_CREDIT 0x0800
+
+/** Name server session started */
+#define FC_LOGIN_NSS_STARTED 0x0800
+
+/** Begin name server session */
+#define FC_LOGIN_NSS_BEGIN 0x0400
+
+/** 1ns error detection timer resolution */
+#define FC_LOGIN_HIRES_E_D_TOV 0x0400
+
+/** Broadcast supported */
+#define FC_LOGIN_BROADCAST 0x0100
+
+/** Query buffer conditions */
+#define FC_LOGIN_QUERY_BUF 0x0040
+
+/** Security */
+#define FC_LOGIN_SECURITY 0x0020
+
+/** Clock sync primitive capable */
+#define FC_LOGIN_CLOCK_SYNC 0x0010
+
+/** Short R_T timeout */
+#define FC_LOGIN_SHORT_R_T_TOV 0x0008
+
+/** Dynamic half duplex */
+#define FC_LOGIN_DHD 0x0004
+
+/** Continuously increasing sequence count */
+#define FC_LOGIN_CONTINUOUS_SEQ 0x0002
+
+/** Payload */
+#define FC_LOGIN_PAYLOAD 0x0001
+
+/** Fibre Channel default MTU */
+#define FC_LOGIN_DEFAULT_MTU 1452
+
+/** Default maximum number of concurrent sequences */
+#define FC_LOGIN_DEFAULT_MAX_SEQ 255
+
+/** Default relative offset by info category */
+#define FC_LOGIN_DEFAULT_REL_OFFS 0x1f
+
+/** Default E_D timeout value */
+#define FC_LOGIN_DEFAULT_E_D_TOV 2000
+
+/** Fibre Channel class-specific login parameters */
+struct fc_login_class {
+	/** Flags */
+	uint16_t flags;
+	/** Initiator flags */
+	uint16_t init_flags;
+	/** Recipient flags */
+	uint16_t recip_flags;
+	/** Receive data field size */
+	uint16_t mtu;
+	/** Maximum number of concurrent sequences */
+	uint16_t max_seq;
+	/** End-to-end credit */
+	uint16_t credit;
+	/** Reserved */
+	uint8_t reserved0;
+	/** Maximum number of open sequences per exchange */
+	uint8_t max_seq_per_xchg;
+	/** Reserved */
+	uint8_t reserved1[2];
+} __attribute__ (( packed ));
+
+/** Class valid */
+#define FC_LOGIN_CLASS_VALID 0x8000
+
+/** Sequential delivery requested */
+#define FC_LOGIN_CLASS_SEQUENTIAL 0x0800
+
+/** A Fibre Channel FLOGI/PLOGI frame */
+struct fc_login_frame {
+	/** ELS command code */
+	uint8_t command;
+	/** Reserved */
+	uint8_t reserved[3];
+	/** Common service parameters */
+	struct fc_login_common common;
+	/** Port name */
+	struct fc_name port_wwn;
+	/** Node name */
+	struct fc_name node_wwn;
+	/** Class 1 service parameters */
+	struct fc_login_class class1;
+	/** Class 2 service parameters */
+	struct fc_login_class class2;
+	/** Class 3 service parameters */
+	struct fc_login_class class3;
+	/** Class 4 service parameters */
+	struct fc_login_class class4;
+	/** Vendor version level */
+	uint8_t vendor_version[16];
+} __attribute__ (( packed ));
+
+/** A Fibre Channel LOGO request frame */
+struct fc_logout_request_frame {
+	/** ELS command code */
+	uint8_t command;
+	/** Reserved */
+	uint8_t reserved[4];
+	/** Port ID */
+	struct fc_port_id port_id;
+	/** Port name */
+	struct fc_name port_wwn;
+} __attribute__ (( packed ));
+
+/** A Fibre Channel LOGO response frame */
+struct fc_logout_response_frame {
+	/** ELS command code */
+	uint8_t command;
+	/** Reserved */
+	uint8_t reserved[3];
+} __attribute__ (( packed ));
+
+/** A Fibre Channel PRLI service parameter page */
+struct fc_prli_page {
+	/** Type code */
+	uint8_t type;
+	/** Type code extension */
+	uint8_t type_ext;
+	/** Flags and response code */
+	uint16_t flags;
+	/** Reserved */
+	uint32_t reserved[2];
+} __attribute__ (( packed ));
+
+/** Establish image pair */
+#define FC_PRLI_ESTABLISH 0x2000
+
+/** Response code mask */
+#define FC_PRLI_RESPONSE_MASK 0x0f00
+
+/** Request was executed successfully */
+#define FC_PRLI_RESPONSE_SUCCESS 0x0100
+
+/** A Fibre Channel PRLI frame */
+struct fc_prli_frame {
+	/** ELS command code */
+	uint8_t command;
+	/** Page length */
+	uint8_t page_len;
+	/** Payload length */
+	uint16_t len;
+	/** Service parameter page */
+	struct fc_prli_page page;
+} __attribute__ (( packed ));
+
+/** A Fibre Channel RTV request frame */
+struct fc_rtv_request_frame {
+	/** ELS command code */
+	uint8_t command;
+	/** Reserved */
+	uint8_t reserved[3];
+} __attribute__ (( packed ));
+
+/** A Fibre Channel RTV response frame */
+struct fc_rtv_response_frame {
+	/** ELS command code */
+	uint8_t command;
+	/** Reserved */
+	uint8_t reserved0[3];
+	/** Resource allocation timeout value */
+	uint32_t r_a_tov;
+	/** Error detection timeout value */
+	uint32_t e_d_tov;
+	/** Timeout qualifier */
+	uint16_t flags;
+	/** Reserved */
+	uint16_t reserved1;
+} __attribute__ (( packed ));
+
+/** 1ns error detection timer resolution */
+#define FC_RTV_HIRES_E_D_TOV 0x0400
+
+/** Short R_T timeout */
+#define FC_RTV_SHORT_R_T_TOV 0x0008
+
+/** A Fibre Channel extended link services transaction */
+struct fc_els {
+	/** Reference count */
+	struct refcnt refcnt;
+	/** Job control interface */
+	struct interface job;
+	/** Fibre Channel exchange */
+	struct interface xchg;
+	/** Request sending process */
+	struct process process;
+
+	/** Fibre Channel port */
+	struct fc_port *port;
+	/** Local port ID */
+	struct fc_port_id port_id;
+	/** Peer port ID */
+	struct fc_port_id peer_port_id;
+	/** ELS handler, if known */
+	struct fc_els_handler *handler;
+	/** Flags */
+	unsigned int flags;
+};
+
+/** Fibre Channel extended link services transaction flags */
+enum fc_els_flags {
+	/** ELS transaction is a request */
+	FC_ELS_REQUEST = 0x0001,
+};
+
+/** A Fibre Channel extended link services handler */
+struct fc_els_handler {
+	/** Name */
+	const char *name;
+	/** Transmit ELS request frame
+	 *
+	 * @v els		Fibre Channel ELS transaction
+	 * @ret rc		Return status code
+	 */
+	int ( * tx_request ) ( struct fc_els *els );
+	/** Transmit ELS response frame
+	 *
+	 * @v els		Fibre Channel ELS transaction
+	 * @ret rc		Return status code
+	 */
+	int ( * tx_response ) ( struct fc_els *els );
+	/** Receive ELS request frame
+	 *
+	 * @v els		Fibre Channel ELS transaction
+	 * @v data		ELS frame
+	 * @v len		Length of ELS frame
+	 * @ret rc		Return status code
+	 */
+	int ( * rx_request ) ( struct fc_els *els, const void *data,
+			       size_t len );
+	/** Receive ELS response frame
+	 *
+	 * @v els		Fibre Channel ELS transaction
+	 * @v data		ELS frame
+	 * @v len		Length of ELS frame
+	 * @ret rc		Return status code
+	 */
+	int ( * rx_response ) ( struct fc_els *els, const void *data,
+				size_t len );
+	/** Detect ELS request frame
+	 *
+	 * @v els		Fibre Channel ELS transaction
+	 * @v data		ELS frame
+	 * @v len		Length of ELS frame
+	 * @ret rc		Return status code
+	 */
+	int ( * detect ) ( struct fc_els *els, const void *data, size_t len );
+};
+
+/** Fibre Channel ELS handler table */
+#define FC_ELS_HANDLERS __table ( struct fc_els_handler, "fc_els_handlers" )
+
+/** Declare a Fibre Channel ELS handler */
+#define __fc_els_handler __table_entry ( FC_ELS_HANDLERS, 01 )
+
+/** A Fibre Channel ELS PRLI descriptor */
+struct fc_els_prli_descriptor {
+	/** Upper-layer protocol type */
+	unsigned int type;
+	/** Service parameter length */
+	size_t param_len;
+	/** Fibre Channel ELS handler */
+	struct fc_els_handler *handler;
+};
+
+/** Fibre Channel ELS PRLI descriptor table */
+#define FC_ELS_PRLI_DESCRIPTORS \
+	__table ( struct fc_els_prli_descriptor, "fc_els_prli_descriptors" )
+
+/** Declare a Fibre Channel ELS PRLI descriptor */
+#define __fc_els_prli_descriptor __table_entry ( FC_ELS_PRLI_DESCRIPTORS, 01 )
+
+/**
+ * Check if Fibre Channel ELS transaction is a request
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @ret is_request	ELS transaction is a request
+ */
+static inline int fc_els_is_request ( struct fc_els *els ) {
+	return ( els->flags & FC_ELS_REQUEST );
+}
+
+/**
+ * Calculate ELS command to transmit
+ *
+ * @v els		Fibre Channel ELS transaction
+ * @v request_command	Command for requests
+ * @v command		Command to transmit
+ */
+static inline unsigned int fc_els_tx_command ( struct fc_els *els,
+					       unsigned int request_command ) {
+	return ( fc_els_is_request ( els ) ? request_command : FC_ELS_LS_ACC );
+}
+
+extern int fc_els_tx ( struct fc_els *els, const void *data, size_t len );
+extern int fc_els_request ( struct interface *job, struct fc_port *port,
+			    struct fc_port_id *peer_port_id,
+			    struct fc_els_handler *handler );
+extern int fc_els_flogi ( struct interface *parent, struct fc_port *port );
+extern int fc_els_plogi ( struct interface *parent, struct fc_port *port,
+			  struct fc_port_id *peer_port_id );
+extern int fc_els_logo ( struct interface *parent, struct fc_port *port,
+			 struct fc_port_id *peer_port_id );
+extern int fc_els_prli ( struct interface *parent, struct fc_port *port,
+			 struct fc_port_id *peer_port_id, unsigned int type );
+extern int fc_els_prli_tx ( struct fc_els *els,
+			    struct fc_els_prli_descriptor *descriptor,
+			    void *param );
+extern int fc_els_prli_rx ( struct fc_els *els,
+			    struct fc_els_prli_descriptor *descriptor,
+			    const void *data, size_t len );
+extern int fc_els_prli_detect ( struct fc_els *els __unused,
+				struct fc_els_prli_descriptor *descriptor,
+				const void *data, size_t len );
+
+#endif /* _IPXE_FCELS_H */
diff --git a/src/include/ipxe/xfer.h b/src/include/ipxe/xfer.h
index 0c0303279..1167e5cba 100644
--- a/src/include/ipxe/xfer.h
+++ b/src/include/ipxe/xfer.h
@@ -46,6 +46,22 @@ struct xfer_metadata {
 /** Offset is absolute */
 #define XFER_FL_ABS_OFFSET 0x0001
 
+/** Sender is relinquishing use of half-duplex channel */
+#define XFER_FL_OVER 0x0002
+
+/** This is the final data transfer */
+#define XFER_FL_OUT 0x0004
+
+/** Data content represents a command or status message
+ *
+ * The flag @c XFER_FL_RESPONSE is used to distinguish between a
+ * command message and a status message.
+ */
+#define XFER_FL_CMD_STAT 0x0008
+
+/** Data content is a response */
+#define XFER_FL_RESPONSE 0x0010
+
 /* Data transfer interface operations */
 
 extern int xfer_vredirect ( struct interface *intf, int type,