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/*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
FILE_LICENCE ( GPL2_OR_LATER );
/**
* @file
*
* iPXE scripts
*
*/
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <errno.h>
#include <getopt.h>
#include <ipxe/command.h>
#include <ipxe/parseopt.h>
#include <ipxe/image.h>
#include <ipxe/shell.h>
/** Currently running script
*
* This is a global in order to allow goto_exec() to update the
* offset.
*/
static struct image *script;
/** Offset within current script
*
* This is a global in order to allow goto_exec() to update the
* offset.
*/
static size_t script_offset;
/**
* Process script lines
*
* @v process_line Line processor
* @v terminate Termination check
* @ret rc Return status code
*/
static int process_script ( int ( * process_line ) ( const char *line ),
int ( * terminate ) ( int rc ) ) {
off_t eol;
size_t len;
int rc;
script_offset = 0;
do {
/* Find length of next line, excluding any terminating '\n' */
eol = memchr_user ( script->data, script_offset, '\n',
( script->len - script_offset ) );
if ( eol < 0 )
eol = script->len;
len = ( eol - script_offset );
/* Copy line, terminate with NUL, and execute command */
{
char cmdbuf[ len + 1 ];
copy_from_user ( cmdbuf, script->data,
script_offset, len );
cmdbuf[len] = '\0';
DBG ( "$ %s\n", cmdbuf );
/* Move to next line */
script_offset += ( len + 1 );
/* Process line */
rc = process_line ( cmdbuf );
if ( terminate ( rc ) )
return rc;
}
} while ( script_offset < script->len );
return rc;
}
/**
* Terminate script processing on shell exit or command failure
*
* @v rc Line processing status
* @ret terminate Terminate script processing
*/
static int terminate_on_exit_or_failure ( int rc ) {
return ( shell_stopped ( SHELL_STOP_COMMAND_SEQUENCE ) ||
( rc != 0 ) );
}
/**
* Execute script line
*
* @v line Line of script
* @ret rc Return status code
*/
static int script_exec_line ( const char *line ) {
int rc;
/* Skip label lines */
if ( line[0] == ':' )
return 0;
/* Execute command */
if ( ( rc = system ( line ) ) != 0 )
return rc;
return 0;
}
/**
* Execute script
*
* @v image Script
* @ret rc Return status code
*/
static int script_exec ( struct image *image ) {
struct image *saved_script;
size_t saved_offset;
int rc;
/* Temporarily de-register image, so that a "boot" command
* doesn't throw us into an execution loop.
*/
unregister_image ( image );
/* Preserve state of any currently-running script */
saved_script = script;
saved_offset = script_offset;
/* Initialise state for this script */
script = image;
/* Process script */
rc = process_script ( script_exec_line, terminate_on_exit_or_failure );
/* Restore saved state, re-register image, and return */
script_offset = saved_offset;
script = saved_script;
register_image ( image );
return rc;
}
/**
* Probe script image
*
* @v image Script
* @ret rc Return status code
*/
static int script_probe ( struct image *image ) {
static const char ipxe_magic[] = "#!ipxe";
static const char gpxe_magic[] = "#!gpxe";
linker_assert ( sizeof ( ipxe_magic ) == sizeof ( gpxe_magic ),
magic_size_mismatch );
char test[ sizeof ( ipxe_magic ) - 1 /* NUL */
+ 1 /* terminating space */];
/* Sanity check */
if ( image->len < sizeof ( test ) ) {
DBG ( "Too short to be a script\n" );
return -ENOEXEC;
}
/* Check for magic signature */
copy_from_user ( test, image->data, 0, sizeof ( test ) );
if ( ! ( ( ( memcmp ( test, ipxe_magic, sizeof ( test ) - 1 ) == 0 ) ||
( memcmp ( test, gpxe_magic, sizeof ( test ) - 1 ) == 0 )) &&
isspace ( test[ sizeof ( test ) - 1 ] ) ) ) {
DBG ( "Invalid magic signature\n" );
return -ENOEXEC;
}
return 0;
}
/** Script image type */
struct image_type script_image_type __image_type ( PROBE_NORMAL ) = {
.name = "script",
.probe = script_probe,
.exec = script_exec,
};
/** "goto" options */
struct goto_options {};
/** "goto" option list */
static struct option_descriptor goto_opts[] = {};
/** "goto" command descriptor */
static struct command_descriptor goto_cmd =
COMMAND_DESC ( struct goto_options, goto_opts, 1, 1, "<label>" );
/**
* Current "goto" label
*
* Valid only during goto_exec(). Consider this part of a closure.
*/
static const char *goto_label;
/**
* Check for presence of label
*
* @v line Script line
* @ret rc Return status code
*/
static int goto_find_label ( const char *line ) {
if ( line[0] != ':' )
return -ENOENT;
if ( strcmp ( goto_label, &line[1] ) != 0 )
return -ENOENT;
return 0;
}
/**
* Terminate script processing when label is found
*
* @v rc Line processing status
* @ret terminate Terminate script processing
*/
static int terminate_on_label_found ( int rc ) {
return ( rc == 0 );
}
/**
* "goto" command
*
* @v argc Argument count
* @v argv Argument list
* @ret rc Return status code
*/
static int goto_exec ( int argc, char **argv ) {
struct goto_options opts;
size_t saved_offset;
int rc;
/* Parse options */
if ( ( rc = parse_options ( argc, argv, &goto_cmd, &opts ) ) != 0 )
return rc;
/* Sanity check */
if ( ! script ) {
printf ( "Not in a script\n" );
return -ENOTTY;
}
/* Parse label */
goto_label = argv[optind];
/* Find label */
saved_offset = script_offset;
if ( ( rc = process_script ( goto_find_label,
terminate_on_label_found ) ) != 0 ) {
script_offset = saved_offset;
return rc;
}
/* Terminate processing of current command */
shell_stop ( SHELL_STOP_COMMAND );
return 0;
}
/** "goto" command */
struct command goto_command __command = {
.name = "goto",
.exec = goto_exec,
};
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