fcns.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/interface.h>
#include <ipxe/iobuf.h>
#include <ipxe/process.h>
#include <ipxe/xfer.h>
#include <ipxe/fc.h>
#include <ipxe/fcns.h>

/** @file
 *
 * Fibre Channel name server lookups
 *
 */

/** A Fibre Channel name server query */
struct fc_ns_query {
        /** Reference count */
        struct refcnt refcnt;
        /** Fibre Channel exchange */
        struct interface xchg;

        /** Fibre Channel peer */
        struct fc_peer *peer;
        /** Fibre Channel port */
        struct fc_port *port;

        /** Process */
        struct process process;
        /** Success handler
         *
         * @v peer              Fibre Channel peer
         * @v port              Fibre Channel port
         * @v peer_port_id      Peer port ID
         * @ret rc              Return status code
         */
        int ( * done ) ( struct fc_peer *peer, struct fc_port *port,
                         struct fc_port_id *peer_port_id );
};

/**
 * Free name server query
 *
 * @v refcnt            Reference count
 */
static void fc_ns_query_free ( struct refcnt *refcnt ) {
        struct fc_ns_query *query =
                container_of ( refcnt, struct fc_ns_query, refcnt );

        fc_peer_put ( query->peer );
        fc_port_put ( query->port );
        free ( query );
}

/**
 * Close name server query
 *
 * @v query             Name server query
 * @v rc                Reason for close
 */
static void fc_ns_query_close ( struct fc_ns_query *query, int rc ) {

        /* Stop process */
        process_del ( &query->process );

        /* Shut down interfaces */
        intf_shutdown ( &query->xchg, rc );
}

/**
 * Receive name server query response
 *
 * @v query             Name server query
 * @v iobuf             I/O buffer
 * @v meta              Data transfer metadata
 * @ret rc              Return status code
 */
static int fc_ns_query_deliver ( struct fc_ns_query *query,
                                 struct io_buffer *iobuf,
                                 struct xfer_metadata *meta __unused ) {
        union fc_ns_response *resp = iobuf->data;
        struct fc_port_id *peer_port_id;
        int rc;

        /* Sanity check */
        if ( iob_len ( iobuf ) < sizeof ( resp->ct ) ) {
                DBGC ( query, "FCNS %p received underlength response (%zd "
                       "bytes)\n", query, iob_len ( iobuf ) );
                rc = -EINVAL;
                goto done;
        }

        /* Handle response */
        switch ( ntohs ( resp->ct.code ) ) {
        case FC_GS_ACCEPT:
                if ( iob_len ( iobuf ) < sizeof ( resp->gid_pn ) ) {
                        DBGC ( query, "FCNS %p received underlength accept "
                               "response (%zd bytes)\n",
                               query, iob_len ( iobuf ) );
                        rc = -EINVAL;
                        goto done;
                }
                peer_port_id = &resp->gid_pn.port_id.port_id;
                DBGC ( query, "FCNS %p resolved %s to %s via %s\n",
                       query, fc_ntoa ( &query->peer->port_wwn ),
                       fc_id_ntoa ( peer_port_id ), query->port->name );
                if ( ( rc = query->done ( query->peer, query->port,
                                          peer_port_id ) ) != 0 )
                        goto done;
                break;
        case FC_GS_REJECT:
                DBGC ( query, "FCNS %p rejected (reason %02x explanation "
                       "%02x)\n", query, resp->reject.ct.reason,
                       resp->reject.ct.explanation );
                break;
        default:
                DBGC ( query, "FCNS %p received invalid response code %04x\n",
                       query, ntohs ( resp->ct.code ) );
                rc = -ENOTSUP;
                goto done;
        }

        rc = 0;
 done:
        free_iob ( iobuf );
        fc_ns_query_close ( query, rc );
        return rc;
}

/**
 * Name server query process
 *
 * @v query             Name server query
 */
static void fc_ns_query_step ( struct fc_ns_query *query ) {
        struct xfer_metadata meta;
        struct fc_ns_gid_pn_request gid_pn;
        int xchg_id;
        int rc;

        /* Create exchange */
        if ( ( xchg_id = fc_xchg_originate ( &query->xchg, query->port,
                                             &fc_gs_port_id,
                                             FC_TYPE_CT ) ) < 0 ) {
                rc = xchg_id;
                DBGC ( query, "FCNS %p could not create exchange: %s\n",
                       query, strerror ( rc ) );
                fc_ns_query_close ( query, rc );
                return;
        }

        /* Construct query request */
        memset ( &gid_pn, 0, sizeof ( gid_pn ) );
        gid_pn.ct.revision = FC_CT_REVISION;
        gid_pn.ct.type = FC_GS_TYPE_DS;
        gid_pn.ct.subtype = FC_DS_SUBTYPE_NAME;
        gid_pn.ct.code = htons ( FC_NS_GET ( FC_NS_PORT_NAME, FC_NS_PORT_ID ));
        memcpy ( &gid_pn.port_wwn, &query->peer->port_wwn,
                 sizeof ( gid_pn.port_wwn ) );
        memset ( &meta, 0, sizeof ( meta ) );
        meta.flags = XFER_FL_OVER;

        /* Send query */
        if ( ( rc = xfer_deliver_raw_meta ( &query->xchg, &gid_pn,
                                            sizeof ( gid_pn ), &meta ) ) != 0){
                DBGC ( query, "FCNS %p could not deliver query: %s\n",
                       query, strerror ( rc ) );
                fc_ns_query_close ( query, rc );
                return;
        }
}

/** Name server exchange interface operations */
static struct interface_operation fc_ns_query_xchg_op[] = {
        INTF_OP ( xfer_deliver, struct fc_ns_query *, fc_ns_query_deliver ),
        INTF_OP ( intf_close, struct fc_ns_query *, fc_ns_query_close ),
};

/** Name server exchange interface descriptor */
static struct interface_descriptor fc_ns_query_xchg_desc =
        INTF_DESC ( struct fc_ns_query, xchg, fc_ns_query_xchg_op );

/** Name server process descriptor */
static struct process_descriptor fc_ns_query_process_desc =
        PROC_DESC_ONCE ( struct fc_ns_query, process, fc_ns_query_step );

/**
 * Issue Fibre Channel name server query
 *
 * @v peer              Fibre Channel peer
 * @v port              Fibre Channel port
 * @ret rc              Return status code
 */
int fc_ns_query ( struct fc_peer *peer, struct fc_port *port,
                  int ( * done ) ( struct fc_peer *peer, struct fc_port *port,
                                   struct fc_port_id *peer_port_id ) ) {
        struct fc_ns_query *query;

        /* Allocate and initialise structure */
        query = zalloc ( sizeof ( *query ) );
        if ( ! query )
                return -ENOMEM;
        ref_init ( &query->refcnt, fc_ns_query_free );
        intf_init ( &query->xchg, &fc_ns_query_xchg_desc, &query->refcnt );
        process_init ( &query->process, &fc_ns_query_process_desc,
                       &query->refcnt );
        query->peer = fc_peer_get ( peer );
        query->port = fc_port_get ( port );
        query->done = done;

        DBGC ( query, "FCNS %p querying %s via %s\n",
               query, fc_ntoa ( &query->peer->port_wwn ), port->name );

        /* Mortalise self and return */
        ref_put ( &query->refcnt );
        return 0;
}