src/arch/x86/interface/pxe/pxe_file.c

/** @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 ),
};