pxe_file.c

Go to the documentation of this file.

/** @file
 *
 * PXE FILE API
 *
 */

#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <byteswap.h>
#include <ipxe/uaccess.h>
#include <ipxe/posix_io.h>
#include <ipxe/features.h>
#include <pxe.h>
#include <realmode.h>

/*
 * Copyright (C) 2007 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 );

FEATURE ( FEATURE_MISC, "PXEXT", DHCP_EB_FEATURE_PXE_EXT, 2 );

/**
 * FILE OPEN
 *
 * @v file_open                         Pointer to a struct s_PXENV_FILE_OPEN
 * @v s_PXENV_FILE_OPEN::FileName       URL of file to open
 * @ret #PXENV_EXIT_SUCCESS             File was opened
 * @ret #PXENV_EXIT_FAILURE             File was not opened
 * @ret s_PXENV_FILE_OPEN::Status       PXE status code
 * @ret s_PXENV_FILE_OPEN::FileHandle   Handle of opened file
 *
 */
static PXENV_EXIT_t pxenv_file_open ( struct s_PXENV_FILE_OPEN *file_open ) {
        userptr_t filename;
        size_t filename_len;
        int fd;

        DBG ( "PXENV_FILE_OPEN" );

        /* Copy name from external program, and open it */
        filename = real_to_user ( file_open->FileName.segment,
                              file_open->FileName.offset );
        filename_len = strlen_user ( filename, 0 );
        {
                char uri_string[ filename_len + 1 ];

                copy_from_user ( uri_string, filename, 0,
                                 sizeof ( uri_string ) );
                DBG ( " %s", uri_string );
                fd = open ( uri_string );
        }

        if ( fd < 0 ) {
                file_open->Status = PXENV_STATUS ( fd );
                return PXENV_EXIT_FAILURE;
        }

        DBG ( " as file %d", fd );

        file_open->FileHandle = fd;
        file_open->Status = PXENV_STATUS_SUCCESS;
        return PXENV_EXIT_SUCCESS;
}

/**
 * FILE CLOSE
 *
 * @v file_close                        Pointer to a struct s_PXENV_FILE_CLOSE
 * @v s_PXENV_FILE_CLOSE::FileHandle    File handle
 * @ret #PXENV_EXIT_SUCCESS             File was closed
 * @ret #PXENV_EXIT_FAILURE             File was not closed
 * @ret s_PXENV_FILE_CLOSE::Status      PXE status code
 *
 */
static PXENV_EXIT_t pxenv_file_close ( struct s_PXENV_FILE_CLOSE *file_close ) {

        DBG ( "PXENV_FILE_CLOSE %d", file_close->FileHandle );

        close ( file_close->FileHandle );
        file_close->Status = PXENV_STATUS_SUCCESS;
        return PXENV_EXIT_SUCCESS;
}

/**
 * FILE SELECT
 *
 * @v file_select                       Pointer to a struct s_PXENV_FILE_SELECT
 * @v s_PXENV_FILE_SELECT::FileHandle   File handle
 * @ret #PXENV_EXIT_SUCCESS             File has been checked for readiness
 * @ret #PXENV_EXIT_FAILURE             File has not been checked for readiness
 * @ret s_PXENV_FILE_SELECT::Status     PXE status code
 * @ret s_PXENV_FILE_SELECT::Ready      Indication of readiness
 *
 */
static PXENV_EXIT_t
pxenv_file_select ( struct s_PXENV_FILE_SELECT *file_select ) {
        fd_set fdset;
        int ready;

        DBG ( "PXENV_FILE_SELECT %d", file_select->FileHandle );

        FD_ZERO ( &fdset );
        FD_SET ( file_select->FileHandle, &fdset );
        if ( ( ready = select ( &fdset, 0 ) ) < 0 ) {
                file_select->Status = PXENV_STATUS ( ready );
                return PXENV_EXIT_FAILURE;
        }

        file_select->Ready = ( ready ? RDY_READ : 0 );
        file_select->Status = PXENV_STATUS_SUCCESS;
        return PXENV_EXIT_SUCCESS;
}

/**
 * FILE READ
 *
 * @v file_read                         Pointer to a struct s_PXENV_FILE_READ
 * @v s_PXENV_FILE_READ::FileHandle     File handle
 * @v s_PXENV_FILE_READ::BufferSize     Size of data buffer
 * @v s_PXENV_FILE_READ::Buffer         Data buffer
 * @ret #PXENV_EXIT_SUCCESS             Data has been read from file
 * @ret #PXENV_EXIT_FAILURE             Data has not been read from file
 * @ret s_PXENV_FILE_READ::Status       PXE status code
 * @ret s_PXENV_FILE_READ::Ready        Indication of readiness
 * @ret s_PXENV_FILE_READ::BufferSize   Length of data read
 *
 */
static PXENV_EXIT_t pxenv_file_read ( struct s_PXENV_FILE_READ *file_read ) {
        userptr_t buffer;
        ssize_t len;

        DBG ( "PXENV_FILE_READ %d to %04x:%04x+%04x", file_read->FileHandle,
              file_read->Buffer.segment, file_read->Buffer.offset,
              file_read->BufferSize );

        buffer = real_to_user ( file_read->Buffer.segment,
                                file_read->Buffer.offset );
        if ( ( len = read_user ( file_read->FileHandle, buffer, 0,
                                file_read->BufferSize ) ) < 0 ) {
                file_read->Status = PXENV_STATUS ( len );
                return PXENV_EXIT_FAILURE;
        }

        DBG ( " read %04zx", ( ( size_t ) len ) );

        file_read->BufferSize = len;
        file_read->Status = PXENV_STATUS_SUCCESS;
        return PXENV_EXIT_SUCCESS;
}

/**
 * GET FILE SIZE
 *
 * @v get_file_size                     Pointer to a struct s_PXENV_GET_FILE_SIZE
 * @v s_PXENV_GET_FILE_SIZE::FileHandle File handle
 * @ret #PXENV_EXIT_SUCCESS             File size has been determined
 * @ret #PXENV_EXIT_FAILURE             File size has not been determined
 * @ret s_PXENV_GET_FILE_SIZE::Status   PXE status code
 * @ret s_PXENV_GET_FILE_SIZE::FileSize Size of file
 */
static PXENV_EXIT_t
pxenv_get_file_size ( struct s_PXENV_GET_FILE_SIZE *get_file_size ) {
        ssize_t filesize;

        DBG ( "PXENV_GET_FILE_SIZE %d", get_file_size->FileHandle );

        filesize = fsize ( get_file_size->FileHandle );
        if ( filesize < 0 ) {
                get_file_size->Status = PXENV_STATUS ( filesize );
                return PXENV_EXIT_FAILURE;
        }

        DBG ( " is %zd", ( ( size_t ) filesize ) );

        get_file_size->FileSize = filesize;
        get_file_size->Status = PXENV_STATUS_SUCCESS;
        return PXENV_EXIT_SUCCESS;
}

/**
 * FILE EXEC
 *
 * @v file_exec                         Pointer to a struct s_PXENV_FILE_EXEC
 * @v s_PXENV_FILE_EXEC::Command        Command to execute
 * @ret #PXENV_EXIT_SUCCESS             Command was executed successfully
 * @ret #PXENV_EXIT_FAILURE             Command was not executed successfully
 * @ret s_PXENV_FILE_EXEC::Status       PXE status code
 *
 */
static PXENV_EXIT_t pxenv_file_exec ( struct s_PXENV_FILE_EXEC *file_exec ) {
        userptr_t command;
        size_t command_len;
        int rc;

        DBG ( "PXENV_FILE_EXEC" );

        /* Copy name from external program, and exec it */
        command = real_to_user ( file_exec->Command.segment,
                                 file_exec->Command.offset );
        command_len = strlen_user ( command, 0 );
        {
                char command_string[ command_len + 1 ];

                copy_from_user ( command_string, command, 0,
                                 sizeof ( command_string ) );
                DBG ( " %s", command_string );

                if ( ( rc = system ( command_string ) ) != 0 ) {
                        file_exec->Status = PXENV_STATUS ( rc );
                        return PXENV_EXIT_FAILURE;
                }
        }

        file_exec->Status = PXENV_STATUS_SUCCESS;
        return PXENV_EXIT_SUCCESS;
}

/**
 * FILE CMDLINE
 *
 * @v file_cmdline                      Pointer to a struct s_PXENV_FILE_CMDLINE
 * @v s_PXENV_FILE_CMDLINE::Buffer      Buffer to contain command line
 * @v s_PXENV_FILE_CMDLINE::BufferSize  Size of buffer
 * @ret #PXENV_EXIT_SUCCESS             Command was executed successfully
 * @ret #PXENV_EXIT_FAILURE             Command was not executed successfully
 * @ret s_PXENV_FILE_EXEC::Status       PXE status code
 * @ret s_PXENV_FILE_EXEC::BufferSize   Length of command line (including NUL)
 *
 */
static PXENV_EXIT_t
pxenv_file_cmdline ( struct s_PXENV_FILE_CMDLINE *file_cmdline ) {
        userptr_t buffer;
        size_t max_len;
        size_t len;

        DBG ( "PXENV_FILE_CMDLINE to %04x:%04x+%04x \"%s\"\n",
              file_cmdline->Buffer.segment, file_cmdline->Buffer.offset,
              file_cmdline->BufferSize, pxe_cmdline );

        buffer = real_to_user ( file_cmdline->Buffer.segment,
                                file_cmdline->Buffer.offset );
        len = file_cmdline->BufferSize;
        max_len = ( pxe_cmdline ?
                    ( strlen ( pxe_cmdline ) + 1 /* NUL */ ) : 0 );
        if ( len > max_len )
                len = max_len;
        copy_to_user ( buffer, 0, pxe_cmdline, len );
        file_cmdline->BufferSize = max_len;

        file_cmdline->Status = PXENV_STATUS_SUCCESS;
        return PXENV_EXIT_SUCCESS;
}

/**
 * FILE API CHECK
 *
 * @v file_exec                         Pointer to a struct s_PXENV_FILE_API_CHECK
 * @v s_PXENV_FILE_API_CHECK::Magic     Inbound magic number (0x91d447b2)
 * @ret #PXENV_EXIT_SUCCESS             Command was executed successfully
 * @ret #PXENV_EXIT_FAILURE             Command was not executed successfully
 * @ret s_PXENV_FILE_API_CHECK::Status  PXE status code
 * @ret s_PXENV_FILE_API_CHECK::Magic   Outbound magic number (0xe9c17b20)
 * @ret s_PXENV_FILE_API_CHECK::Provider "iPXE" (0x45585067)
 * @ret s_PXENV_FILE_API_CHECK::APIMask API function bitmask
 * @ret s_PXENV_FILE_API_CHECK::Flags   Reserved
 *
 */
static PXENV_EXIT_t
pxenv_file_api_check ( struct s_PXENV_FILE_API_CHECK *file_api_check ) {
        struct pxe_api_call *call;
        unsigned int mask = 0;
        unsigned int offset;

        DBG ( "PXENV_FILE_API_CHECK" );

        /* Check for magic value */
        if ( file_api_check->Magic != 0x91d447b2 ) {
                file_api_check->Status = PXENV_STATUS_BAD_FUNC;
                return PXENV_EXIT_FAILURE;
        }

        /* Check for required parameter size */
        if ( file_api_check->Size < sizeof ( *file_api_check ) ) {
                file_api_check->Status = PXENV_STATUS_OUT_OF_RESOURCES;
                return PXENV_EXIT_FAILURE;
        }

        /* Determine supported calls */
        for_each_table_entry ( call, PXE_API_CALLS ) {
                offset = ( call->opcode - PXENV_FILE_MIN );
                if ( offset <= ( PXENV_FILE_MAX - PXENV_FILE_MIN ) )
                        mask |= ( 1 << offset );
        }

        /* Fill in parameters */
        file_api_check->Size = sizeof ( *file_api_check );
        file_api_check->Magic = 0xe9c17b20;
        file_api_check->Provider = 0x45585067; /* "iPXE" */
        file_api_check->APIMask = mask;
        file_api_check->Flags = 0; /* None defined */

        file_api_check->Status = PXENV_STATUS_SUCCESS;
        return PXENV_EXIT_SUCCESS;
}

/** PXE file API */
struct pxe_api_call pxe_file_api[] __pxe_api_call = {
        PXE_API_CALL ( PXENV_FILE_OPEN, pxenv_file_open,
                       struct s_PXENV_FILE_OPEN ),
        PXE_API_CALL ( PXENV_FILE_CLOSE, pxenv_file_close,
                       struct s_PXENV_FILE_CLOSE ),
        PXE_API_CALL ( PXENV_FILE_SELECT, pxenv_file_select,
                       struct s_PXENV_FILE_SELECT ),
        PXE_API_CALL ( PXENV_FILE_READ, pxenv_file_read,
                       struct s_PXENV_FILE_READ ),
        PXE_API_CALL ( PXENV_GET_FILE_SIZE, pxenv_get_file_size,
                       struct s_PXENV_GET_FILE_SIZE ),
        PXE_API_CALL ( PXENV_FILE_EXEC, pxenv_file_exec,
                       struct s_PXENV_FILE_EXEC ),
        PXE_API_CALL ( PXENV_FILE_CMDLINE, pxenv_file_cmdline,
                       struct s_PXENV_FILE_CMDLINE ),
        PXE_API_CALL ( PXENV_FILE_API_CHECK, pxenv_file_api_check,
                       struct s_PXENV_FILE_API_CHECK ),
};