fcoe.c

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/*
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 * You can also choose to distribute this program under the terms of
 * the Unmodified Binary Distribution Licence (as given in the file
 * COPYING.UBDL), provided that you have satisfied its requirements.
 */

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <byteswap.h>
#include <ipxe/if_ether.h>
#include <ipxe/if_arp.h>
#include <ipxe/iobuf.h>
#include <ipxe/interface.h>
#include <ipxe/xfer.h>
#include <ipxe/netdevice.h>
#include <ipxe/ethernet.h>
#include <ipxe/vlan.h>
#include <ipxe/features.h>
#include <ipxe/errortab.h>
#include <ipxe/device.h>
#include <ipxe/crc32.h>
#include <ipxe/retry.h>
#include <ipxe/timer.h>
#include <ipxe/fc.h>
#include <ipxe/fip.h>
#include <ipxe/fcoe.h>

/** @file
 *
 * FCoE protocol
 *
 */

FEATURE ( FEATURE_PROTOCOL, "FCoE", DHCP_EB_FEATURE_FCOE, 1 );

/* Disambiguate the various error causes */
#define EINVAL_UNDERLENGTH __einfo_error ( EINFO_EINVAL_UNDERLENGTH )
#define EINFO_EINVAL_UNDERLENGTH \
        __einfo_uniqify ( EINFO_EINVAL, 0x01, "Underlength packet" )
#define EINVAL_SOF __einfo_error ( EINFO_EINVAL_SOF )
#define EINFO_EINVAL_SOF \
        __einfo_uniqify ( EINFO_EINVAL, 0x02, "Invalid SoF delimiter" )
#define EINVAL_CRC __einfo_error ( EINFO_EINVAL_CRC )
#define EINFO_EINVAL_CRC \
        __einfo_uniqify ( EINFO_EINVAL, 0x03, "Invalid CRC (not stripped?)" )
#define EINVAL_EOF __einfo_error ( EINFO_EINVAL_EOF )
#define EINFO_EINVAL_EOF \
        __einfo_uniqify ( EINFO_EINVAL, 0x04, "Invalid EoF delimiter" )

/** An FCoE port */
struct fcoe_port {
        /** Transport interface */
        struct interface transport;
        /** Network device */
        struct net_device *netdev;

        /** Node WWN */
        union fcoe_name node_wwn;
        /** Port WWN */
        union fcoe_name port_wwn;

        /** FIP retransmission timer */
        struct retry_timer timer;
        /** FIP timeout counter */
        unsigned int timeouts;
        /** Flags */
        unsigned int flags;
        /** FCoE forwarder priority */
        unsigned int priority;
        /** Keepalive delay (in ms) */
        unsigned int keepalive;
        /** FCoE forwarder MAC address */
        uint8_t fcf_mac[ETH_ALEN];
        /** Local MAC address */
        uint8_t local_mac[ETH_ALEN];
};

/** FCoE flags */
enum fcoe_flags {
        /** Underlying network device is available */
        FCOE_HAVE_NETWORK = 0x0001,
        /** We have selected an FCoE forwarder to use */
        FCOE_HAVE_FCF = 0x0002,
        /** We have a FIP-capable FCoE forwarder available to be used */
        FCOE_HAVE_FIP_FCF = 0x0004,
        /** FCoE forwarder supports server-provided MAC addresses */
        FCOE_FCF_ALLOWS_SPMA = 0x0008,
        /** An alternative VLAN has been found */
        FCOE_VLAN_FOUND = 0x0010,
        /** VLAN discovery has timed out */
        FCOE_VLAN_TIMED_OUT = 0x0020,
};

struct net_driver fcoe_driver __net_driver;
struct net_protocol fcoe_protocol __net_protocol;
struct net_protocol fip_protocol __net_protocol;

/** FCoE All-FCoE-MACs address */
static uint8_t all_fcoe_macs[ETH_ALEN] =
        { 0x01, 0x10, 0x18, 0x01, 0x00, 0x00 };

/** FCoE All-ENode-MACs address */
static uint8_t all_enode_macs[ETH_ALEN] =
        { 0x01, 0x10, 0x18, 0x01, 0x00, 0x01 };

/** FCoE All-FCF-MACs address */
static uint8_t all_fcf_macs[ETH_ALEN] =
        { 0x01, 0x10, 0x18, 0x01, 0x00, 0x02 };

/** Default FCoE forwarded MAC address */
static uint8_t default_fcf_mac[ETH_ALEN] =
        { 0x0e, 0xfc, 0x00, 0xff, 0xff, 0xfe };

/** Maximum number of VLAN requests before giving up on VLAN discovery */
#define FCOE_MAX_VLAN_REQUESTS 2

/** Delay between retrying VLAN requests */
#define FCOE_VLAN_RETRY_DELAY ( TICKS_PER_SEC )

/** Delay between retrying polling VLAN requests */
#define FCOE_VLAN_POLL_DELAY ( 30 * TICKS_PER_SEC )

/** Maximum number of FIP solicitations before giving up on FIP */
#define FCOE_MAX_FIP_SOLICITATIONS 2

/** Delay between retrying FIP solicitations */
#define FCOE_FIP_RETRY_DELAY ( TICKS_PER_SEC )

/** Maximum number of missing discovery advertisements */
#define FCOE_MAX_FIP_MISSING_KEEPALIVES 4

/******************************************************************************
 *
 * FCoE protocol
 *
 ******************************************************************************
 */

/**
 * Reset FCoE port
 *
 * @v fcoe              FCoE port
 */
static void fcoe_reset ( struct fcoe_port *fcoe ) {

        /* Detach FC port, if any */
        intf_restart ( &fcoe->transport, -ECANCELED );

        /* Reset any FIP state */
        stop_timer ( &fcoe->timer );
        fcoe->timeouts = 0;
        fcoe->flags = 0;
        fcoe->priority = ( FIP_LOWEST_PRIORITY + 1 );
        fcoe->keepalive = 0;
        memcpy ( fcoe->fcf_mac, default_fcf_mac,
                 sizeof ( fcoe->fcf_mac ) );
        memcpy ( fcoe->local_mac, fcoe->netdev->ll_addr,
                 sizeof ( fcoe->local_mac ) );

        /* Start FIP solicitation if network is available */
        if ( netdev_is_open ( fcoe->netdev ) &&
             netdev_link_ok ( fcoe->netdev ) ) {
                fcoe->flags |= FCOE_HAVE_NETWORK;
                start_timer_nodelay ( &fcoe->timer );
                DBGC ( fcoe, "FCoE %s starting %s\n", fcoe->netdev->name,
                       ( vlan_can_be_trunk ( fcoe->netdev ) ?
                         "VLAN discovery" : "FIP solicitation" ) );
        }

        /* Send notification of window change */
        xfer_window_changed ( &fcoe->transport );
}

/**
 * Transmit FCoE packet
 *
 * @v fcoe              FCoE port
 * @v iobuf             I/O buffer
 * @v meta              Data transfer metadata
 * @ret rc              Return status code
 */
static int fcoe_deliver ( struct fcoe_port *fcoe,
                          struct io_buffer *iobuf,
                          struct xfer_metadata *meta __unused ) {
        struct fc_frame_header *fchdr = iobuf->data;
        struct fc_els_frame_common *els = ( iobuf->data + sizeof ( *fchdr ) );
        struct fcoe_header *fcoehdr;
        struct fcoe_footer *fcoeftr;
        struct fip_header *fiphdr;
        struct fip_login *fipflogi;
        struct fip_mac_address *fipmac;
        uint32_t crc;
        struct net_protocol *net_protocol;
        void *ll_source;
        int rc;

        /* Send as FIP or FCoE as appropriate */
        if ( ( fchdr->r_ctl == ( FC_R_CTL_ELS | FC_R_CTL_UNSOL_CTRL ) ) &&
             ( els->command == FC_ELS_FLOGI ) &&
             ( fcoe->flags & FCOE_HAVE_FIP_FCF ) ) {

                /* Create FIP FLOGI descriptor */
                fipflogi = iob_push ( iobuf,
                                      offsetof ( typeof ( *fipflogi ), fc ) );
                memset ( fipflogi, 0, offsetof ( typeof ( *fipflogi ), fc ) );
                fipflogi->type = FIP_FLOGI;
                fipflogi->len = ( iob_len ( iobuf ) / 4 );

                /* Create FIP MAC address descriptor */
                fipmac = iob_put ( iobuf, sizeof ( *fipmac ) );
                memset ( fipmac, 0, sizeof ( *fipmac ) );
                fipmac->type = FIP_MAC_ADDRESS;
                fipmac->len = ( sizeof ( *fipmac ) / 4 );
                if ( fcoe->flags & FCOE_FCF_ALLOWS_SPMA ) {
                        memcpy ( fipmac->mac, fcoe->netdev->ll_addr,
                                 sizeof ( fipmac->mac ) );
                }

                /* Create FIP header */
                fiphdr = iob_push ( iobuf, sizeof ( *fiphdr ) );
                memset ( fiphdr, 0, sizeof ( *fiphdr ) );
                fiphdr->version = FIP_VERSION;
                fiphdr->code = htons ( FIP_CODE_ELS );
                fiphdr->subcode = FIP_ELS_REQUEST;
                fiphdr->len =
                        htons ( ( iob_len ( iobuf ) - sizeof ( *fiphdr ) ) / 4);
                fiphdr->flags = ( ( fcoe->flags & FCOE_FCF_ALLOWS_SPMA ) ?
                                  htons ( FIP_SP ) : htons ( FIP_FP ) );

                /* Send as FIP packet from netdev's own MAC address */
                net_protocol = &fip_protocol;
                ll_source = fcoe->netdev->ll_addr;

        } else {

                /* Calculate CRC */
                crc = crc32_le ( ~((uint32_t)0), iobuf->data,
                                 iob_len ( iobuf ) );

                /* Create FCoE header */
                fcoehdr = iob_push ( iobuf, sizeof ( *fcoehdr ) );
                memset ( fcoehdr, 0, sizeof ( *fcoehdr ) );
                fcoehdr->sof = ( ( fchdr->seq_cnt == ntohs ( 0 ) ) ?
                                 FCOE_SOF_I3 : FCOE_SOF_N3 );

                /* Create FCoE footer */
                fcoeftr = iob_put ( iobuf, sizeof ( *fcoeftr ) );
                memset ( fcoeftr, 0, sizeof ( *fcoeftr ) );
                fcoeftr->crc = cpu_to_le32 ( crc ^ ~((uint32_t)0) );
                fcoeftr->eof = ( ( fchdr->f_ctl_es & FC_F_CTL_ES_END ) ?
                                 FCOE_EOF_T : FCOE_EOF_N );

                /* Send as FCoE packet from FCoE MAC address */
                net_protocol = &fcoe_protocol;
                ll_source = fcoe->local_mac;
        }

        /* Transmit packet */
        if ( ( rc = net_tx ( iob_disown ( iobuf ), fcoe->netdev, net_protocol,
                             fcoe->fcf_mac, ll_source ) ) != 0 ) {
                DBGC ( fcoe, "FCoE %s could not transmit: %s\n",
                       fcoe->netdev->name, strerror ( rc ) );
                goto done;
        }

 done:
        free_iob ( iobuf );
        return rc;
}

/**
 * Allocate FCoE I/O buffer
 *
 * @v len               Payload length
 * @ret iobuf           I/O buffer, or NULL
 */
static struct io_buffer * fcoe_alloc_iob ( struct fcoe_port *fcoe __unused,
                                           size_t len ) {
        struct io_buffer *iobuf;

        iobuf = alloc_iob ( MAX_LL_HEADER_LEN + sizeof ( struct fcoe_header ) +
                            len + sizeof ( struct fcoe_footer ) );
        if ( iobuf ) {
                iob_reserve ( iobuf, ( MAX_LL_HEADER_LEN +
                                       sizeof ( struct fcoe_header ) ) );
        }
        return iobuf;
}

/**
 * Process incoming FCoE packets
 *
 * @v iobuf             I/O buffer
 * @v netdev            Network device
 * @v ll_dest           Link-layer destination address
 * @v ll_source         Link-layer source address
 * @v flags             Packet flags
 * @ret rc              Return status code
 */
static int fcoe_rx ( struct io_buffer *iobuf, struct net_device *netdev,
                     const void *ll_dest, const void *ll_source,
                     unsigned int flags __unused ) {
        struct fcoe_header *fcoehdr;
        struct fcoe_footer *fcoeftr;
        struct fcoe_port *fcoe;
        int rc;

        /* Identify FCoE port */
        fcoe = netdev_priv ( netdev, &fcoe_driver );
        if ( ! fcoe->netdev ) {
                DBG ( "FCoE received frame for net device %s missing FCoE "
                      "port\n", netdev->name );
                rc = -ENOTCONN;
                goto done;
        }

        /* Discard packets not destined for us */
        if ( ( memcmp ( fcoe->local_mac, ll_dest,
                        sizeof ( fcoe->local_mac ) ) != 0 ) &&
             ( memcmp ( default_fcf_mac, ll_dest,
                        sizeof ( default_fcf_mac ) ) != 0 ) ) {
                DBGC2 ( fcoe, "FCoE %s ignoring packet for %s\n",
                        fcoe->netdev->name, eth_ntoa ( ll_dest ) );
                rc = -ENOTCONN;
                goto done;
        }

        /* Sanity check */
        if ( iob_len ( iobuf ) < ( sizeof ( *fcoehdr ) + sizeof ( *fcoeftr ) )){
                DBGC ( fcoe, "FCoE %s received under-length frame (%zd "
                       "bytes)\n", fcoe->netdev->name, iob_len ( iobuf ) );
                rc = -EINVAL_UNDERLENGTH;
                goto done;
        }

        /* Strip header and footer */
        fcoehdr = iobuf->data;
        iob_pull ( iobuf, sizeof ( *fcoehdr ) );
        fcoeftr = ( iobuf->data + iob_len ( iobuf ) - sizeof ( *fcoeftr ) );
        iob_unput ( iobuf, sizeof ( *fcoeftr ) );

        /* Validity checks */
        if ( fcoehdr->version != FCOE_FRAME_VER ) {
                DBGC ( fcoe, "FCoE %s received unsupported frame version "
                       "%02x\n", fcoe->netdev->name, fcoehdr->version );
                rc = -EPROTONOSUPPORT;
                goto done;
        }
        if ( ! ( ( fcoehdr->sof == FCOE_SOF_I3 ) ||
                 ( fcoehdr->sof == FCOE_SOF_N3 ) ) ) {
                DBGC ( fcoe, "FCoE %s received unsupported start-of-frame "
                       "delimiter %02x\n", fcoe->netdev->name, fcoehdr->sof );
                rc = -EINVAL_SOF;
                goto done;
        }
        if ( ( le32_to_cpu ( fcoeftr->crc ) ^ ~((uint32_t)0) ) !=
             crc32_le ( ~((uint32_t)0), iobuf->data, iob_len ( iobuf ) ) ) {
                DBGC ( fcoe, "FCoE %s received invalid CRC\n",
                       fcoe->netdev->name );
                rc = -EINVAL_CRC;
                goto done;
        }
        if ( ! ( ( fcoeftr->eof == FCOE_EOF_N ) ||
                 ( fcoeftr->eof == FCOE_EOF_T ) ) ) {
                DBGC ( fcoe, "FCoE %s received unsupported end-of-frame "
                       "delimiter %02x\n", fcoe->netdev->name, fcoeftr->eof );
                rc = -EINVAL_EOF;
                goto done;
        }

        /* Record FCF address if applicable */
        if ( ( fcoe->flags & FCOE_HAVE_FCF ) &&
             ( ! ( fcoe->flags & FCOE_HAVE_FIP_FCF ) ) ) {
                memcpy ( &fcoe->fcf_mac, ll_source, sizeof ( fcoe->fcf_mac ) );
        }

        /* Hand off via transport interface */
        if ( ( rc = xfer_deliver_iob ( &fcoe->transport,
                                       iob_disown ( iobuf ) ) ) != 0 ) {
                DBGC ( fcoe, "FCoE %s could not deliver frame: %s\n",
                       fcoe->netdev->name, strerror ( rc ) );
                goto done;
        }

 done:
        free_iob ( iobuf );
        return rc;
}

/**
 * Check FCoE flow control window
 *
 * @v fcoe              FCoE port
 * @ret len             Length of window
 */
static size_t fcoe_window ( struct fcoe_port *fcoe ) {
        return ( ( fcoe->flags & FCOE_HAVE_FCF ) ? ~( ( size_t ) 0 ) : 0 );
}

/**
 * Close FCoE port
 *
 * @v fcoe              FCoE port
 * @v rc                Reason for close
 */
static void fcoe_close ( struct fcoe_port *fcoe, int rc ) {

        stop_timer ( &fcoe->timer );
        intf_shutdown ( &fcoe->transport, rc );
}

/**
 * Identify device underlying FCoE port
 *
 * @v fcoe              FCoE port
 * @ret device          Underlying device
 */
static struct device * fcoe_identify_device ( struct fcoe_port *fcoe ) {
        return fcoe->netdev->dev;
}

/** FCoE transport interface operations */
static struct interface_operation fcoe_transport_op[] = {
        INTF_OP ( xfer_deliver, struct fcoe_port *, fcoe_deliver ),
        INTF_OP ( xfer_alloc_iob, struct fcoe_port *, fcoe_alloc_iob ),
        INTF_OP ( xfer_window, struct fcoe_port *, fcoe_window ),
        INTF_OP ( intf_close, struct fcoe_port *, fcoe_close ),
        INTF_OP ( identify_device, struct fcoe_port *,
                  fcoe_identify_device ),
};

/** FCoE transport interface descriptor */
static struct interface_descriptor fcoe_transport_desc =
        INTF_DESC ( struct fcoe_port, transport, fcoe_transport_op );

/******************************************************************************
 *
 * FIP protocol
 *
 ******************************************************************************
 */

/**
 * Parse FIP packet into descriptor set
 *
 * @v fcoe              FCoE port
 * @v fiphdr            FIP header
 * @v len               Length of FIP packet
 * @v descs             Descriptor set to fill in
 * @ret rc              Return status code
 */
static int fcoe_fip_parse ( struct fcoe_port *fcoe, struct fip_header *fiphdr,
                            size_t len, struct fip_descriptors *descs ) {
        union fip_descriptor *desc;
        size_t descs_len;
        size_t desc_len;
        size_t desc_offset;
        unsigned int desc_type;

        /* Check FIP version */
        if ( fiphdr->version != FIP_VERSION ) {
                DBGC ( fcoe, "FCoE %s received unsupported FIP version %02x\n",
                       fcoe->netdev->name, fiphdr->version );
                return -EINVAL;
        }

        /* Check length */
        descs_len = ( ntohs ( fiphdr->len ) * 4 );
        if ( ( sizeof ( *fiphdr ) + descs_len ) > len ) {
                DBGC ( fcoe, "FCoE %s received bad descriptor list length\n",
                       fcoe->netdev->name );
                return -EINVAL;
        }

        /* Parse descriptor list */
        memset ( descs, 0, sizeof ( *descs ) );
        for ( desc_offset = 0 ;
              desc_offset <= ( descs_len - sizeof ( desc->common ) ) ;
              desc_offset += desc_len ) {

                /* Find descriptor and validate length */
                desc = ( ( ( void * ) ( fiphdr + 1 ) ) + desc_offset );
                desc_type = desc->common.type;
                desc_len = ( desc->common.len * 4 );
                if ( desc_len == 0 ) {
                        DBGC ( fcoe, "FCoE %s received zero-length "
                               "descriptor\n", fcoe->netdev->name );
                        return -EINVAL;
                }
                if ( ( desc_offset + desc_len ) > descs_len ) {
                        DBGC ( fcoe, "FCoE %s descriptor overrun\n",
                               fcoe->netdev->name );
                        return -EINVAL;
                }

                /* Handle descriptors that we understand */
                if ( ( desc_type > FIP_RESERVED ) &&
                     ( desc_type < FIP_NUM_DESCRIPTOR_TYPES ) ) {
                        /* Use only the first instance of a descriptor */
                        if ( descs->desc[desc_type] == NULL )
                                descs->desc[desc_type] = desc;
                        continue;
                }

                /* Abort if we cannot understand a critical descriptor */
                if ( FIP_IS_CRITICAL ( desc_type ) ) {
                        DBGC ( fcoe, "FCoE %s cannot understand critical "
                               "descriptor type %02x\n",
                               fcoe->netdev->name, desc_type );
                        return -ENOTSUP;
                }

                /* Ignore non-critical descriptors that we cannot understand */
        }

        return 0;
}

/**
 * Send FIP VLAN request
 *
 * @v fcoe              FCoE port
 * @ret rc              Return status code
 */
static int fcoe_fip_tx_vlan ( struct fcoe_port *fcoe ) {
        struct io_buffer *iobuf;
        struct {
                struct fip_header hdr;
                struct fip_mac_address mac_address;
        } __attribute__ (( packed )) *request;
        int rc;

        /* Allocate I/O buffer */
        iobuf = alloc_iob ( MAX_LL_HEADER_LEN + sizeof ( *request ) );
        if ( ! iobuf )
                return -ENOMEM;
        iob_reserve ( iobuf, MAX_LL_HEADER_LEN );

        /* Construct VLAN request */
        request = iob_put ( iobuf, sizeof ( *request ) );
        memset ( request, 0, sizeof ( *request ) );
        request->hdr.version = FIP_VERSION;
        request->hdr.code = htons ( FIP_CODE_VLAN );
        request->hdr.subcode = FIP_VLAN_REQUEST;
        request->hdr.len = htons ( ( sizeof ( *request ) -
                                     sizeof ( request->hdr ) ) / 4 );
        request->mac_address.type = FIP_MAC_ADDRESS;
        request->mac_address.len =
                ( sizeof ( request->mac_address ) / 4 );
        memcpy ( request->mac_address.mac, fcoe->netdev->ll_addr,
                 sizeof ( request->mac_address.mac ) );

        /* Send VLAN request */
        if ( ( rc = net_tx ( iob_disown ( iobuf ), fcoe->netdev,
                             &fip_protocol, all_fcf_macs,
                             fcoe->netdev->ll_addr ) ) != 0 ) {
                DBGC ( fcoe, "FCoE %s could not send VLAN request: "
                       "%s\n", fcoe->netdev->name, strerror ( rc ) );
                return rc;
        }

        return 0;
}

/**
 * Handle received FIP VLAN notification
 *
 * @v fcoe              FCoE port
 * @v descs             Descriptor list
 * @v flags             Flags
 * @ret rc              Return status code
 */
static int fcoe_fip_rx_vlan ( struct fcoe_port *fcoe,
                              struct fip_descriptors *descs,
                              unsigned int flags __unused ) {
        struct fip_mac_address *mac_address = fip_mac_address ( descs );
        struct fip_vlan *vlan = fip_vlan ( descs );
        unsigned int tag;
        int rc;

        /* Sanity checks */
        if ( ! mac_address ) {
                DBGC ( fcoe, "FCoE %s received VLAN notification missing MAC "
                       "address\n", fcoe->netdev->name );
                return -EINVAL;
        }
        if ( ! vlan ) {
                DBGC ( fcoe, "FCoE %s received VLAN notification missing VLAN "
                       "tag\n", fcoe->netdev->name );
                return -EINVAL;
        }

        /* Create VLAN */
        tag = ntohs ( vlan->vlan );
        DBGC ( fcoe, "FCoE %s creating VLAN %d for FCF %s\n",
               fcoe->netdev->name, tag, eth_ntoa ( mac_address->mac ) );
        if ( ( rc = vlan_create ( fcoe->netdev, tag,
                                  FCOE_VLAN_PRIORITY ) ) != 0 ) {
                DBGC ( fcoe, "FCoE %s could not create VLAN %d: %s\n",
                       fcoe->netdev->name, tag, strerror ( rc ) );
                return rc;
        }

        /* Record that a VLAN was found.  This FCoE port will play no
         * further active role; the real FCoE traffic will use the
         * port automatically created for the new VLAN device.
         */
        fcoe->flags |= FCOE_VLAN_FOUND;

        return 0;
}

/**
 * Send FIP discovery solicitation
 *
 * @v fcoe              FCoE port
 * @ret rc              Return status code
 */
static int fcoe_fip_tx_solicitation ( struct fcoe_port *fcoe ) {
        struct io_buffer *iobuf;
        struct {
                struct fip_header hdr;
                struct fip_mac_address mac_address;
                struct fip_name_id name_id;
                struct fip_max_fcoe_size max_fcoe_size;
        } __attribute__ (( packed )) *solicitation;
        int rc;

        /* Allocate I/O buffer */
        iobuf = alloc_iob ( MAX_LL_HEADER_LEN + sizeof ( *solicitation ) );
        if ( ! iobuf )
                return -ENOMEM;
        iob_reserve ( iobuf, MAX_LL_HEADER_LEN );

        /* Construct discovery solicitation */
        solicitation = iob_put ( iobuf, sizeof ( *solicitation ) );
        memset ( solicitation, 0, sizeof ( *solicitation ) );
        solicitation->hdr.version = FIP_VERSION;
        solicitation->hdr.code = htons ( FIP_CODE_DISCOVERY );
        solicitation->hdr.subcode = FIP_DISCOVERY_SOLICIT;
        solicitation->hdr.len = htons ( ( sizeof ( *solicitation ) -
                                          sizeof ( solicitation->hdr ) ) / 4 );
        solicitation->hdr.flags = htons ( FIP_FP | FIP_SP );
        solicitation->mac_address.type = FIP_MAC_ADDRESS;
        solicitation->mac_address.len =
                ( sizeof ( solicitation->mac_address ) / 4 );
        memcpy ( solicitation->mac_address.mac, fcoe->netdev->ll_addr,
                 sizeof ( solicitation->mac_address.mac ) );
        solicitation->name_id.type = FIP_NAME_ID;
        solicitation->name_id.len = ( sizeof ( solicitation->name_id ) / 4 );
        memcpy ( &solicitation->name_id.name, &fcoe->node_wwn.fc,
                 sizeof ( solicitation->name_id.name ) );
        solicitation->max_fcoe_size.type = FIP_MAX_FCOE_SIZE;
        solicitation->max_fcoe_size.len =
                ( sizeof ( solicitation->max_fcoe_size ) / 4 );
        solicitation->max_fcoe_size.mtu =
                htons ( ETH_MAX_MTU - sizeof ( struct fcoe_header ) -
                        sizeof ( struct fcoe_footer ) );

        /* Send discovery solicitation */
        if ( ( rc = net_tx ( iob_disown ( iobuf ), fcoe->netdev,
                             &fip_protocol, all_fcf_macs,
                             fcoe->netdev->ll_addr ) ) != 0 ) {
                DBGC ( fcoe, "FCoE %s could not send discovery solicitation: "
                       "%s\n", fcoe->netdev->name, strerror ( rc ) );
                return rc;
        }

        return 0;
}

/**
 * Handle received FIP discovery advertisement
 *
 * @v fcoe              FCoE port
 * @v descs             Descriptor list
 * @v flags             Flags
 * @ret rc              Return status code
 */
static int fcoe_fip_rx_advertisement ( struct fcoe_port *fcoe,
                                       struct fip_descriptors *descs,
                                       unsigned int flags ) {
        struct fip_priority *priority = fip_priority ( descs );
        struct fip_mac_address *mac_address = fip_mac_address ( descs );
        struct fip_fka_adv_p *fka_adv_p = fip_fka_adv_p ( descs );

        /* Sanity checks */
        if ( ! priority ) {
                DBGC ( fcoe, "FCoE %s received advertisement missing "
                       "priority\n", fcoe->netdev->name );
                return -EINVAL;
        }
        if ( ! mac_address ) {
                DBGC ( fcoe, "FCoE %s received advertisement missing MAC "
                       "address\n", fcoe->netdev->name );
                return -EINVAL;
        }
        if ( ! fka_adv_p ) {
                DBGC ( fcoe, "FCoE %s received advertisement missing FKA ADV "
                       "period\n", fcoe->netdev->name );
                return -EINVAL;
        }

        if ( ! ( fcoe->flags & FCOE_HAVE_FCF ) ) {

                /* We are soliciting for an FCF.  Store the highest
                 * (i.e. lowest-valued) priority solicited
                 * advertisement that we receive.
                 */
                if ( ( ( flags & ( FIP_A | FIP_S | FIP_F ) ) ==
                       ( FIP_A | FIP_S | FIP_F ) ) &&
                     ( priority->priority < fcoe->priority ) ) {

                        fcoe->flags |= FCOE_HAVE_FIP_FCF;
                        fcoe->priority = priority->priority;
                        if ( fka_adv_p->flags & FIP_NO_KEEPALIVE ) {
                                fcoe->keepalive = 0;
                        } else {
                                fcoe->keepalive = ntohl ( fka_adv_p->period );
                        }
                        fcoe->flags &= ~FCOE_FCF_ALLOWS_SPMA;
                        if ( flags & FIP_SP )
                                fcoe->flags |= FCOE_FCF_ALLOWS_SPMA;
                        memcpy ( fcoe->fcf_mac, mac_address->mac,
                                 sizeof ( fcoe->fcf_mac ) );
                        DBGC ( fcoe, "FCoE %s selected FCF %s (pri %d",
                               fcoe->netdev->name, eth_ntoa ( fcoe->fcf_mac ),
                               fcoe->priority );
                        if ( fcoe->keepalive ) {
                                DBGC ( fcoe, ", FKA ADV %dms",
                                       fcoe->keepalive );
                        }
                        DBGC ( fcoe, ", %cPMA)\n",
                               ( ( fcoe->flags & FCOE_FCF_ALLOWS_SPMA ) ?
                                 'S' : 'F' ) );
                }

        } else if ( fcoe->flags & FCOE_HAVE_FIP_FCF ) {

                /* We are checking that the FCF remains alive.  Reset
                 * the timeout counter if this is an advertisement
                 * from our forwarder.
                 */
                if ( memcmp ( fcoe->fcf_mac, mac_address->mac,
                              sizeof ( fcoe->fcf_mac ) ) == 0 ) {
                        fcoe->timeouts = 0;
                }

        } else {

                /* We are operating in non-FIP mode and have received
                 * a FIP advertisement.  Reset the link in order to
                 * attempt FIP.
                 */
                fcoe_reset ( fcoe );

        }

        return 0;
}

/**
 * Handle received FIP ELS response
 *
 * @v fcoe              FCoE port
 * @v descs             Descriptor list
 * @v flags             Flags
 * @ret rc              Return status code
 */
static int fcoe_fip_rx_els_response ( struct fcoe_port *fcoe,
                                      struct fip_descriptors *descs,
                                      unsigned int flags __unused ) {
        struct fip_els *flogi = fip_flogi ( descs );
        struct fip_mac_address *mac_address = fip_mac_address ( descs );
        void *frame;
        size_t frame_len;
        int rc;

        /* Sanity checks */
        if ( ! flogi ) {
                DBGC ( fcoe, "FCoE %s received ELS response missing FLOGI\n",
                       fcoe->netdev->name );
                return -EINVAL;
        }
        if ( ! mac_address ) {
                DBGC ( fcoe, "FCoE %s received ELS response missing MAC "
                       "address\n", fcoe->netdev->name );
                return -EINVAL;
        }

        /* Record local MAC address */
        memcpy ( fcoe->local_mac, mac_address->mac, sizeof ( fcoe->local_mac ));
        DBGC ( fcoe, "FCoE %s using local MAC %s\n",
               fcoe->netdev->name, eth_ntoa ( fcoe->local_mac ) );

        /* Hand off via transport interface */
        frame = &flogi->fc;
        frame_len = ( ( flogi->len * 4 ) - offsetof ( typeof ( *flogi ), fc ) );
        if ( ( rc = xfer_deliver_raw ( &fcoe->transport, frame,
                                       frame_len ) ) != 0 ) {
                DBGC ( fcoe, "FCoE %s could not deliver FIP FLOGI frame: %s\n",
                       fcoe->netdev->name, strerror ( rc ) );
                return rc;
        }

        return 0;
}

/**
 * Send FIP keepalive
 *
 * @v fcoe              FCoE port
 * @ret rc              Return status code
 */
static int fcoe_fip_tx_keepalive ( struct fcoe_port *fcoe ) {
        struct io_buffer *iobuf;
        struct {
                struct fip_header hdr;
                struct fip_mac_address mac_address;
        } __attribute__ (( packed )) *keepalive;
        int rc;

        /* Allocate I/O buffer */
        iobuf = alloc_iob ( MAX_LL_HEADER_LEN + sizeof ( *keepalive ) );
        if ( ! iobuf )
                return -ENOMEM;
        iob_reserve ( iobuf, MAX_LL_HEADER_LEN );

        /* Construct keepalive */
        keepalive = iob_put ( iobuf, sizeof ( *keepalive ) );
        memset ( keepalive, 0, sizeof ( *keepalive ) );
        keepalive->hdr.version = FIP_VERSION;
        keepalive->hdr.code = htons ( FIP_CODE_MAINTAIN );
        keepalive->hdr.subcode = FIP_MAINTAIN_KEEP_ALIVE;
        keepalive->hdr.len =    htons ( ( sizeof ( *keepalive ) -
                                          sizeof ( keepalive->hdr ) ) / 4 );
        keepalive->mac_address.type = FIP_MAC_ADDRESS;
        keepalive->mac_address.len =
                ( sizeof ( keepalive->mac_address ) / 4 );
        memcpy ( keepalive->mac_address.mac, fcoe->netdev->ll_addr,
                 sizeof ( keepalive->mac_address.mac ) );

        /* Send keepalive */
        if ( ( rc = net_tx ( iob_disown ( iobuf ), fcoe->netdev,
                             &fip_protocol, fcoe->fcf_mac,
                             fcoe->netdev->ll_addr ) ) != 0 ) {
                DBGC ( fcoe, "FCoE %s could not send keepalive: %s\n",
                       fcoe->netdev->name, strerror ( rc ) );
                return rc;
        }

        return 0;
}

/** A FIP handler */
struct fip_handler {
        /** Protocol code */
        uint16_t code;
        /** Protocol subcode */
        uint8_t subcode;
        /**
         * Receive FIP packet
         *
         * @v fcoe              FCoE port
         * @v descs             Descriptor list
         * @v flags             Flags
         * @ret rc              Return status code
         */
        int ( * rx ) ( struct fcoe_port *fcoe, struct fip_descriptors *descs,
                       unsigned int flags );
};

/** FIP handlers */
static struct fip_handler fip_handlers[] = {
        { FIP_CODE_VLAN, FIP_VLAN_NOTIFY,
          fcoe_fip_rx_vlan },
        { FIP_CODE_DISCOVERY, FIP_DISCOVERY_ADVERTISE,
          fcoe_fip_rx_advertisement },
        { FIP_CODE_ELS, FIP_ELS_RESPONSE,
          fcoe_fip_rx_els_response },
};

/**
 * Process incoming FIP packets
 *
 * @v iobuf             I/O buffer
 * @v netdev            Network device
 * @v ll_dest           Link-layer destination address
 * @v ll_source         Link-layer source address
 * @v flags             Packet flags
 * @ret rc              Return status code
 */
static int fcoe_fip_rx ( struct io_buffer *iobuf,
                         struct net_device *netdev,
                         const void *ll_dest,
                         const void *ll_source __unused,
                         unsigned int flags __unused ) {
        struct fip_header *fiphdr = iobuf->data;
        struct fip_descriptors descs;
        struct fip_handler *handler;
        struct fcoe_port *fcoe;
        unsigned int i;
        int rc;

        /* Identify FCoE port */
        fcoe = netdev_priv ( netdev, &fcoe_driver );
        if ( ! fcoe->netdev ) {
                DBG ( "FCoE received FIP frame for net device %s missing FCoE "
                      "port\n", netdev->name );
                rc = -ENOTCONN;
                goto done;
        }

        /* Discard packets not destined for us */
        if ( ( memcmp ( fcoe->netdev->ll_addr, ll_dest, ETH_ALEN ) != 0 ) &&
             ( memcmp ( all_fcoe_macs, ll_dest,
                        sizeof ( all_fcoe_macs ) ) != 0 ) &&
             ( memcmp ( all_enode_macs, ll_dest,
                        sizeof ( all_enode_macs ) ) != 0 ) ) {
                DBGC2 ( fcoe, "FCoE %s ignoring FIP packet for %s\n",
                        fcoe->netdev->name, eth_ntoa ( ll_dest ) );
                rc = -ENOTCONN;
                goto done;
        }

        /* Parse FIP packet */
        if ( ( rc = fcoe_fip_parse ( fcoe, fiphdr, iob_len ( iobuf ),
                                     &descs ) ) != 0 )
                goto done;

        /* Find a suitable handler */
        for ( i = 0 ; i < ( sizeof ( fip_handlers ) /
                            sizeof ( fip_handlers[0] ) ) ; i++ ) {
                handler = &fip_handlers[i];
                if ( ( handler->code == ntohs ( fiphdr->code ) ) &&
                     ( handler->subcode == fiphdr->subcode ) ) {
                        rc = handler->rx ( fcoe, &descs,
                                           ntohs ( fiphdr->flags ) );
                        goto done;
                }
        }
        DBGC ( fcoe, "FCoE %s received unsupported FIP code %04x.%02x\n",
               fcoe->netdev->name, ntohs ( fiphdr->code ), fiphdr->subcode );
        rc = -ENOTSUP;

 done:
        free_iob ( iobuf );
        return rc;
}

/******************************************************************************
 *
 * FCoE ports
 *
 ******************************************************************************
 */

/**
 * Handle FCoE timer expiry
 *
 * @v timer             FIP timer
 * @v over              Timer expired
 */
static void fcoe_expired ( struct retry_timer *timer, int over __unused ) {
        struct fcoe_port *fcoe =
                container_of ( timer, struct fcoe_port, timer );
        int rc;

        /* Sanity check */
        assert ( fcoe->flags & FCOE_HAVE_NETWORK );

        /* Increment the timeout counter */
        fcoe->timeouts++;

        if ( vlan_can_be_trunk ( fcoe->netdev ) &&
             ! ( fcoe->flags & FCOE_VLAN_TIMED_OUT ) ) {

                /* If we have already found a VLAN, send infrequent
                 * VLAN requests, in case VLAN information changes.
                 */
                if ( fcoe->flags & FCOE_VLAN_FOUND ) {
                        fcoe->flags &= ~FCOE_VLAN_FOUND;
                        fcoe->timeouts = 0;
                        start_timer_fixed ( &fcoe->timer,
                                            FCOE_VLAN_POLL_DELAY );
                        fcoe_fip_tx_vlan ( fcoe );
                        return;
                }

                /* If we have not yet found a VLAN, and we have not
                 * yet timed out and given up on finding one, then
                 * send a VLAN request and wait.
                 */
                if ( fcoe->timeouts <= FCOE_MAX_VLAN_REQUESTS ) {
                        start_timer_fixed ( &fcoe->timer,
                                            FCOE_VLAN_RETRY_DELAY );
                        fcoe_fip_tx_vlan ( fcoe );
                        return;
                }

                /* We have timed out waiting for a VLAN; proceed to
                 * FIP discovery.
                 */
                fcoe->flags |= FCOE_VLAN_TIMED_OUT;
                fcoe->timeouts = 0;
                DBGC ( fcoe, "FCoE %s giving up on VLAN discovery\n",
                       fcoe->netdev->name );
                start_timer_nodelay ( &fcoe->timer );

        } else if ( ! ( fcoe->flags & FCOE_HAVE_FCF ) ) {

                /* If we have not yet found a FIP-capable forwarder,
                 * and we have not yet timed out and given up on
                 * finding one, then send a FIP solicitation and wait.
                 */
                start_timer_fixed ( &fcoe->timer, FCOE_FIP_RETRY_DELAY );
                if ( ( ! ( fcoe->flags & FCOE_HAVE_FIP_FCF ) ) &&
                     ( fcoe->timeouts <= FCOE_MAX_FIP_SOLICITATIONS ) ) {
                        fcoe_fip_tx_solicitation ( fcoe );
                        return;
                }

                /* Attach Fibre Channel port */
                if ( ( rc = fc_port_open ( &fcoe->transport, &fcoe->node_wwn.fc,
                                           &fcoe->port_wwn.fc,
                                           fcoe->netdev->name ) ) != 0 ) {
                        DBGC ( fcoe, "FCoE %s could not create FC port: %s\n",
                               fcoe->netdev->name, strerror ( rc ) );
                        /* We will try again on the next timer expiry */
                        return;
                }
                stop_timer ( &fcoe->timer );

                /* Either we have found a FIP-capable forwarder, or we
                 * have timed out and will fall back to pre-FIP mode.
                 */
                fcoe->flags |= FCOE_HAVE_FCF;
                fcoe->timeouts = 0;
                DBGC ( fcoe, "FCoE %s using %sFIP FCF %s\n", fcoe->netdev->name,
                       ( ( fcoe->flags & FCOE_HAVE_FIP_FCF ) ? "" : "non-" ),
                       eth_ntoa ( fcoe->fcf_mac ) );

                /* Start sending keepalives if applicable */
                if ( fcoe->keepalive )
                        start_timer_nodelay ( &fcoe->timer );

                /* Send notification of window change */
                xfer_window_changed ( &fcoe->transport );

        } else {

                /* Send keepalive */
                start_timer_fixed ( &fcoe->timer,
                                    ( fcoe->keepalive * TICKS_PER_MS ) );
                fcoe_fip_tx_keepalive ( fcoe );

                /* Abandon FCF if we have not seen its advertisements */
                if ( fcoe->timeouts > FCOE_MAX_FIP_MISSING_KEEPALIVES ) {
                        DBGC ( fcoe, "FCoE %s abandoning FCF %s\n",
                               fcoe->netdev->name, eth_ntoa ( fcoe->fcf_mac ));
                        fcoe_reset ( fcoe );
                }
        }
}

/**
 * Create FCoE port
 *
 * @v netdev            Network device
 * @v priv              Private data
 * @ret rc              Return status code
 */
static int fcoe_probe ( struct net_device *netdev, void *priv ) {
        struct ll_protocol *ll_protocol = netdev->ll_protocol;
        struct fcoe_port *fcoe = priv;

        /* Sanity check */
        if ( ll_protocol->ll_proto != htons ( ARPHRD_ETHER ) ) {
                /* Not an error; simply skip this net device */
                DBG ( "FCoE skipping non-Ethernet device %s\n", netdev->name );
                return 0;
        }

        /* Initialise structure */
        intf_init ( &fcoe->transport, &fcoe_transport_desc, &netdev->refcnt );
        timer_init ( &fcoe->timer, fcoe_expired, &netdev->refcnt );
        fcoe->netdev = netdev;

        /* Construct node and port names */
        fcoe->node_wwn.fcoe.authority = htons ( FCOE_AUTHORITY_IEEE );
        memcpy ( &fcoe->node_wwn.fcoe.mac, netdev->ll_addr,
                 sizeof ( fcoe->node_wwn.fcoe.mac ) );
        fcoe->port_wwn.fcoe.authority = htons ( FCOE_AUTHORITY_IEEE_EXTENDED );
        memcpy ( &fcoe->port_wwn.fcoe.mac, netdev->ll_addr,
                 sizeof ( fcoe->port_wwn.fcoe.mac ) );

        DBGC ( fcoe, "FCoE %s is %s", fcoe->netdev->name,
               fc_ntoa ( &fcoe->node_wwn.fc ) );
        DBGC ( fcoe, " port %s\n", fc_ntoa ( &fcoe->port_wwn.fc ) );

        return 0;
}

/**
 * Handle FCoE port device or link state change
 *
 * @v netdev            Network device
 * @v priv              Private data
 */
static void fcoe_notify ( struct net_device *netdev, void *priv ) {
        struct fcoe_port *fcoe = priv;

        /* Skip non-FCoE net devices */
        if ( ! fcoe->netdev )
                return;

        /* Reset the FCoE link if necessary */
        if ( ! ( netdev_is_open ( netdev ) &&
                 netdev_link_ok ( netdev ) &&
                 ( fcoe->flags & FCOE_HAVE_NETWORK ) ) ) {
                fcoe_reset ( fcoe );
        }
}

/**
 * Destroy FCoE port
 *
 * @v netdev            Network device
 * @v priv              Private data
 */
static void fcoe_remove ( struct net_device *netdev __unused, void *priv ) {
        struct fcoe_port *fcoe = priv;

        /* Skip non-FCoE net devices */
        if ( ! fcoe->netdev )
                return;

        /* Close FCoE device */
        fcoe_close ( fcoe, 0 );
}

/** FCoE driver */
struct net_driver fcoe_driver __net_driver = {
        .name = "FCoE",
        .priv_len = sizeof ( struct fcoe_port ),
        .probe = fcoe_probe,
        .notify = fcoe_notify,
        .remove = fcoe_remove,
};

/** FCoE protocol */
struct net_protocol fcoe_protocol __net_protocol = {
        .name = "FCoE",
        .net_proto = htons ( ETH_P_FCOE ),
        .rx = fcoe_rx,
};

/** FIP protocol */
struct net_protocol fip_protocol __net_protocol = {
        .name = "FIP",
        .net_proto = htons ( ETH_P_FIP ),
        .rx = fcoe_fip_rx,
};

/** Human-readable message for CRC errors
 *
 * It seems as though several drivers neglect to strip the Ethernet
 * CRC, which will cause the FCoE footer to be misplaced and result
 * (coincidentally) in an "invalid CRC" error from FCoE.
 */
struct errortab fcoe_errors[] __errortab = {
        __einfo_errortab ( EINFO_EINVAL_CRC ),
};