efi_path.c

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/*
 * Copyright (C) 2020 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.
 */

#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <byteswap.h>
#include <ipxe/netdevice.h>
#include <ipxe/vlan.h>
#include <ipxe/tcpip.h>
#include <ipxe/uri.h>
#include <ipxe/iscsi.h>
#include <ipxe/aoe.h>
#include <ipxe/fcp.h>
#include <ipxe/ib_srp.h>
#include <ipxe/usb.h>
#include <ipxe/efi/efi.h>
#include <ipxe/efi/efi_driver.h>
#include <ipxe/efi/efi_path.h>

/** @file
 *
 * EFI device paths
 *
 */

/**
 * Find end of device path
 *
 * @v path              Path to device
 * @ret path_end        End of device path
 */
EFI_DEVICE_PATH_PROTOCOL * efi_path_end ( EFI_DEVICE_PATH_PROTOCOL *path ) {

        while ( path->Type != END_DEVICE_PATH_TYPE ) {
                path = ( ( ( void * ) path ) +
                         /* There's this amazing new-fangled thing known as
                          * a UINT16, but who wants to use one of those? */
                         ( ( path->Length[1] << 8 ) | path->Length[0] ) );
        }

        return path;
}

/**
 * Find length of device path (excluding terminator)
 *
 * @v path              Path to device
 * @ret path_len        Length of device path
 */
size_t efi_path_len ( EFI_DEVICE_PATH_PROTOCOL *path ) {
        EFI_DEVICE_PATH_PROTOCOL *end = efi_path_end ( path );

        return ( ( ( void * ) end ) - ( ( void * ) path ) );
}

/**
 * Concatenate EFI device paths
 *
 * @v ...               List of device paths (NULL terminated)
 * @ret path            Concatenated device path, or NULL on error
 *
 * The caller is responsible for eventually calling free() on the
 * allocated device path.
 */
EFI_DEVICE_PATH_PROTOCOL * efi_paths ( EFI_DEVICE_PATH_PROTOCOL *first, ... ) {
        EFI_DEVICE_PATH_PROTOCOL *path;
        EFI_DEVICE_PATH_PROTOCOL *src;
        EFI_DEVICE_PATH_PROTOCOL *dst;
        EFI_DEVICE_PATH_PROTOCOL *end;
        va_list args;
        size_t len;

        /* Calculate device path length */
        va_start ( args, first );
        len = 0;
        src = first;
        while ( src ) {
                len += efi_path_len ( src );
                src = va_arg ( args, EFI_DEVICE_PATH_PROTOCOL * );
        }
        va_end ( args );

        /* Allocate device path */
        path = zalloc ( len + sizeof ( *end ) );
        if ( ! path )
                return NULL;

        /* Populate device path */
        va_start ( args, first );
        dst = path;
        src = first;
        while ( src ) {
                len = efi_path_len ( src );
                memcpy ( dst, src, len );
                dst = ( ( ( void * ) dst ) + len );
                src = va_arg ( args, EFI_DEVICE_PATH_PROTOCOL * );
        }
        va_end ( args );
        end = dst;
        end->Type = END_DEVICE_PATH_TYPE;
        end->SubType = END_ENTIRE_DEVICE_PATH_SUBTYPE;
        end->Length[0] = sizeof ( *end );

        return path;
}

/**
 * Construct EFI device path for network device
 *
 * @v netdev            Network device
 * @ret path            EFI device path, or NULL on error
 *
 * The caller is responsible for eventually calling free() on the
 * allocated device path.
 */
EFI_DEVICE_PATH_PROTOCOL * efi_netdev_path ( struct net_device *netdev ) {
        struct efi_device *efidev;
        EFI_DEVICE_PATH_PROTOCOL *path;
        MAC_ADDR_DEVICE_PATH *macpath;
        VLAN_DEVICE_PATH *vlanpath;
        EFI_DEVICE_PATH_PROTOCOL *end;
        unsigned int tag;
        size_t prefix_len;
        size_t len;

        /* Find parent EFI device */
        efidev = efidev_parent ( netdev->dev );
        if ( ! efidev )
                return NULL;

        /* Calculate device path length */
        prefix_len = efi_path_len ( efidev->path );
        len = ( prefix_len + sizeof ( *macpath ) + sizeof ( *vlanpath ) +
                sizeof ( *end ) );

        /* Allocate device path */
        path = zalloc ( len );
        if ( ! path )
                return NULL;

        /* Construct device path */
        memcpy ( path, efidev->path, prefix_len );
        macpath = ( ( ( void * ) path ) + prefix_len );
        macpath->Header.Type = MESSAGING_DEVICE_PATH;
        macpath->Header.SubType = MSG_MAC_ADDR_DP;
        macpath->Header.Length[0] = sizeof ( *macpath );
        assert ( netdev->ll_protocol->ll_addr_len <
                 sizeof ( macpath->MacAddress ) );
        memcpy ( &macpath->MacAddress, netdev->ll_addr,
                 netdev->ll_protocol->ll_addr_len );
        macpath->IfType = ntohs ( netdev->ll_protocol->ll_proto );
        if ( ( tag = vlan_tag ( netdev ) ) ) {
                vlanpath = ( ( ( void * ) macpath ) + sizeof ( *macpath ) );
                vlanpath->Header.Type = MESSAGING_DEVICE_PATH;
                vlanpath->Header.SubType = MSG_VLAN_DP;
                vlanpath->Header.Length[0] = sizeof ( *vlanpath );
                vlanpath->VlanId = tag;
                end = ( ( ( void * ) vlanpath ) + sizeof ( *vlanpath ) );
        } else {
                end = ( ( ( void * ) macpath ) + sizeof ( *macpath ) );
        }
        end->Type = END_DEVICE_PATH_TYPE;
        end->SubType = END_ENTIRE_DEVICE_PATH_SUBTYPE;
        end->Length[0] = sizeof ( *end );

        return path;
}

/**
 * Construct EFI device path for URI
 *
 * @v uri               URI
 * @ret path            EFI device path, or NULL on error
 *
 * The caller is responsible for eventually calling free() on the
 * allocated device path.
 */
EFI_DEVICE_PATH_PROTOCOL * efi_uri_path ( struct uri *uri ) {
        EFI_DEVICE_PATH_PROTOCOL *path;
        EFI_DEVICE_PATH_PROTOCOL *end;
        URI_DEVICE_PATH *uripath;
        size_t uri_len;
        size_t uripath_len;
        size_t len;

        /* Calculate device path length */
        uri_len = ( format_uri ( uri, NULL, 0 ) + 1 /* NUL */ );
        uripath_len = ( sizeof ( *uripath ) + uri_len );
        len = ( uripath_len + sizeof ( *end ) );

        /* Allocate device path */
        path = zalloc ( len );
        if ( ! path )
                return NULL;

        /* Construct device path */
        uripath = ( ( void * ) path );
        uripath->Header.Type = MESSAGING_DEVICE_PATH;
        uripath->Header.SubType = MSG_URI_DP;
        uripath->Header.Length[0] = ( uripath_len & 0xff );
        uripath->Header.Length[1] = ( uripath_len >> 8 );
        format_uri ( uri, uripath->Uri, uri_len );
        end = ( ( ( void * ) path ) + uripath_len );
        end->Type = END_DEVICE_PATH_TYPE;
        end->SubType = END_ENTIRE_DEVICE_PATH_SUBTYPE;
        end->Length[0] = sizeof ( *end );

        return path;
}

/**
 * Construct EFI device path for iSCSI device
 *
 * @v iscsi             iSCSI session
 * @ret path            EFI device path, or NULL on error
 */
EFI_DEVICE_PATH_PROTOCOL * efi_iscsi_path ( struct iscsi_session *iscsi ) {
        struct sockaddr_tcpip *st_target;
        struct net_device *netdev;
        EFI_DEVICE_PATH_PROTOCOL *netpath;
        EFI_DEVICE_PATH_PROTOCOL *path;
        EFI_DEVICE_PATH_PROTOCOL *end;
        ISCSI_DEVICE_PATH *iscsipath;
        char *name;
        size_t prefix_len;
        size_t name_len;
        size_t iscsi_len;
        size_t len;

        /* Get network device associated with target address */
        st_target = ( ( struct sockaddr_tcpip * ) &iscsi->target_sockaddr );
        netdev = tcpip_netdev ( st_target );
        if ( ! netdev )
                goto err_netdev;

        /* Get network device path */
        netpath = efi_netdev_path ( netdev );
        if ( ! netpath )
                goto err_netpath;

        /* Calculate device path length */
        prefix_len = efi_path_len ( netpath );
        name_len = ( strlen ( iscsi->target_iqn ) + 1 /* NUL */ );
        iscsi_len = ( sizeof ( *iscsipath ) + name_len );
        len = ( prefix_len + iscsi_len + sizeof ( *end ) );

        /* Allocate device path */
        path = zalloc ( len );
        if ( ! path )
                goto err_alloc;

        /* Construct device path */
        memcpy ( path, netpath, prefix_len );
        iscsipath = ( ( ( void * ) path ) + prefix_len );
        iscsipath->Header.Type = MESSAGING_DEVICE_PATH;
        iscsipath->Header.SubType = MSG_ISCSI_DP;
        iscsipath->Header.Length[0] = iscsi_len;
        iscsipath->LoginOption = ISCSI_LOGIN_OPTION_AUTHMETHOD_NON;
        memcpy ( &iscsipath->Lun, &iscsi->lun, sizeof ( iscsipath->Lun ) );
        name = ( ( ( void * ) iscsipath ) + sizeof ( *iscsipath ) );
        memcpy ( name, iscsi->target_iqn, name_len );
        end = ( ( ( void * ) name ) + name_len );
        end->Type = END_DEVICE_PATH_TYPE;
        end->SubType = END_ENTIRE_DEVICE_PATH_SUBTYPE;
        end->Length[0] = sizeof ( *end );

        /* Free temporary paths */
        free ( netpath );

        return path;

 err_alloc:
        free ( netpath );
 err_netpath:
 err_netdev:
        return NULL;
}

/**
 * Construct EFI device path for AoE device
 *
 * @v aoedev            AoE device
 * @ret path            EFI device path, or NULL on error
 */
EFI_DEVICE_PATH_PROTOCOL * efi_aoe_path ( struct aoe_device *aoedev ) {
        struct {
                SATA_DEVICE_PATH sata;
                EFI_DEVICE_PATH_PROTOCOL end;
        } satapath;
        EFI_DEVICE_PATH_PROTOCOL *netpath;
        EFI_DEVICE_PATH_PROTOCOL *path;

        /* Get network device path */
        netpath = efi_netdev_path ( aoedev->netdev );
        if ( ! netpath )
                goto err_netdev;

        /* Construct SATA path */
        memset ( &satapath, 0, sizeof ( satapath ) );
        satapath.sata.Header.Type = MESSAGING_DEVICE_PATH;
        satapath.sata.Header.SubType = MSG_SATA_DP;
        satapath.sata.Header.Length[0] = sizeof ( satapath.sata );
        satapath.sata.HBAPortNumber = aoedev->major;
        satapath.sata.PortMultiplierPortNumber = aoedev->minor;
        satapath.end.Type = END_DEVICE_PATH_TYPE;
        satapath.end.SubType = END_ENTIRE_DEVICE_PATH_SUBTYPE;
        satapath.end.Length[0] = sizeof ( satapath.end );

        /* Construct overall device path */
        path = efi_paths ( netpath, &satapath, NULL );
        if ( ! path )
                goto err_paths;

        /* Free temporary paths */
        free ( netpath );

        return path;

 err_paths:
        free ( netpath );
 err_netdev:
        return NULL;
}

/**
 * Construct EFI device path for Fibre Channel device
 *
 * @v desc              FCP device description
 * @ret path            EFI device path, or NULL on error
 */
EFI_DEVICE_PATH_PROTOCOL * efi_fcp_path ( struct fcp_description *desc ) {
        struct {
                FIBRECHANNELEX_DEVICE_PATH fc;
                EFI_DEVICE_PATH_PROTOCOL end;
        } __attribute__ (( packed )) *path;

        /* Allocate device path */
        path = zalloc ( sizeof ( *path ) );
        if ( ! path )
                return NULL;

        /* Construct device path */
        path->fc.Header.Type = MESSAGING_DEVICE_PATH;
        path->fc.Header.SubType = MSG_FIBRECHANNELEX_DP;
        path->fc.Header.Length[0] = sizeof ( path->fc );
        memcpy ( path->fc.WWN, &desc->wwn, sizeof ( path->fc.WWN ) );
        memcpy ( path->fc.Lun, &desc->lun, sizeof ( path->fc.Lun ) );
        path->end.Type = END_DEVICE_PATH_TYPE;
        path->end.SubType = END_ENTIRE_DEVICE_PATH_SUBTYPE;
        path->end.Length[0] = sizeof ( path->end );

        return &path->fc.Header;
}

/**
 * Construct EFI device path for Infiniband SRP device
 *
 * @v ib_srp            Infiniband SRP device
 * @ret path            EFI device path, or NULL on error
 */
EFI_DEVICE_PATH_PROTOCOL * efi_ib_srp_path ( struct ib_srp_device *ib_srp ) {
        const struct ipxe_ib_sbft *sbft = &ib_srp->sbft;
        union ib_srp_target_port_id *id =
                container_of ( &sbft->srp.target, union ib_srp_target_port_id,
                               srp );
        struct efi_device *efidev;
        EFI_DEVICE_PATH_PROTOCOL *path;
        INFINIBAND_DEVICE_PATH *ibpath;
        EFI_DEVICE_PATH_PROTOCOL *end;
        size_t prefix_len;
        size_t len;

        /* Find parent EFI device */
        efidev = efidev_parent ( ib_srp->ibdev->dev );
        if ( ! efidev )
                return NULL;

        /* Calculate device path length */
        prefix_len = efi_path_len ( efidev->path );
        len = ( prefix_len + sizeof ( *ibpath ) + sizeof ( *end ) );

        /* Allocate device path */
        path = zalloc ( len );
        if ( ! path )
                return NULL;

        /* Construct device path */
        memcpy ( path, efidev->path, prefix_len );
        ibpath = ( ( ( void * ) path ) + prefix_len );
        ibpath->Header.Type = MESSAGING_DEVICE_PATH;
        ibpath->Header.SubType = MSG_INFINIBAND_DP;
        ibpath->Header.Length[0] = sizeof ( *ibpath );
        ibpath->ResourceFlags = INFINIBAND_RESOURCE_FLAG_STORAGE_PROTOCOL;
        memcpy ( ibpath->PortGid, &sbft->ib.dgid, sizeof ( ibpath->PortGid ) );
        memcpy ( &ibpath->ServiceId, &sbft->ib.service_id,
                 sizeof ( ibpath->ServiceId ) );
        memcpy ( &ibpath->TargetPortId, &id->ib.ioc_guid,
                 sizeof ( ibpath->TargetPortId ) );
        memcpy ( &ibpath->DeviceId, &id->ib.id_ext,
                 sizeof ( ibpath->DeviceId ) );
        end = ( ( ( void * ) ibpath ) + sizeof ( *ibpath ) );
        end->Type = END_DEVICE_PATH_TYPE;
        end->SubType = END_ENTIRE_DEVICE_PATH_SUBTYPE;
        end->Length[0] = sizeof ( *end );

        return path;
}

/**
 * Construct EFI device path for USB function
 *
 * @v func              USB function
 * @ret path            EFI device path, or NULL on error
 *
 * The caller is responsible for eventually calling free() on the
 * allocated device path.
 */
EFI_DEVICE_PATH_PROTOCOL * efi_usb_path ( struct usb_function *func ) {
        struct usb_device *usb = func->usb;
        struct efi_device *efidev;
        EFI_DEVICE_PATH_PROTOCOL *path;
        EFI_DEVICE_PATH_PROTOCOL *end;
        USB_DEVICE_PATH *usbpath;
        unsigned int count;
        size_t prefix_len;
        size_t len;

        /* Sanity check */
        assert ( func->desc.count >= 1 );

        /* Find parent EFI device */
        efidev = efidev_parent ( &func->dev );
        if ( ! efidev )
                return NULL;

        /* Calculate device path length */
        count = ( usb_depth ( usb ) + 1 );
        prefix_len = efi_path_len ( efidev->path );
        len = ( prefix_len + ( count * sizeof ( *usbpath ) ) +
                sizeof ( *end ) );

        /* Allocate device path */
        path = zalloc ( len );
        if ( ! path )
                return NULL;

        /* Construct device path */
        memcpy ( path, efidev->path, prefix_len );
        end = ( ( ( void * ) path ) + len - sizeof ( *end ) );
        end->Type = END_DEVICE_PATH_TYPE;
        end->SubType = END_ENTIRE_DEVICE_PATH_SUBTYPE;
        end->Length[0] = sizeof ( *end );
        usbpath = ( ( ( void * ) end ) - sizeof ( *usbpath ) );
        usbpath->InterfaceNumber = func->interface[0];
        for ( ; usb ; usbpath--, usb = usb->port->hub->usb ) {
                usbpath->Header.Type = MESSAGING_DEVICE_PATH;
                usbpath->Header.SubType = MSG_USB_DP;
                usbpath->Header.Length[0] = sizeof ( *usbpath );
                usbpath->ParentPortNumber = ( usb->port->address - 1 );
        }

        return path;
}

/**
 * Describe object as an EFI device path
 *
 * @v intf              Interface
 * @ret path            EFI device path, or NULL
 *
 * The caller is responsible for eventually calling free() on the
 * allocated device path.
 */
EFI_DEVICE_PATH_PROTOCOL * efi_describe ( struct interface *intf ) {
        struct interface *dest;
        efi_describe_TYPE ( void * ) *op =
                intf_get_dest_op ( intf, efi_describe, &dest );
        void *object = intf_object ( dest );
        EFI_DEVICE_PATH_PROTOCOL *path;

        if ( op ) {
                path = op ( object );
        } else {
                path = NULL;
        }

        intf_put ( dest );
        return path;
}