config.c

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/*
 *  Copyright (C) 2001-2003 Hewlett-Packard Co.
 *	Contributed by Stephane Eranian <[e-mail]>
 *
 * This file is part of the ELILO, the EFI Linux boot loader.
 *
 *  ELILO 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, or (at your option)
 *  any later version.
 *
 *  ELILO 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 ELILO; see the file COPYING.  If not, write to the Free
 *  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 *  02111-1307, USA.
 *
 * Please check out the elilo.txt for complete documentation on how
 * to use this program.
 *
 * Portions of this file are derived from the  LILO/x86
 * Copyright 1992-1997 Werner Almesberger. 
 */

#include <efi.h>
#include <efilib.h>
#include <efistdarg.h>

#include "elilo.h"
#include "config.h"

/*
 * The first default config file is architecture dependent. This is useful
 * in case of network booting where the server is used for both types of
 * architectures.
 */
#if defined(CONFIG_ia64)
#define ELILO_ARCH_DEFAULT_CONFIG	L"elilo-ia64.conf"
#elif defined (CONFIG_ia32)
#define ELILO_ARCH_DEFAULT_CONFIG	L"elilo-ia32.conf"
#else
#error "You need to specfy your default arch config file"
#endif

/* 
 * last resort config file. Common to all architectures
 */
#define ELILO_DEFAULT_CONFIG	L"elilo.conf"

#define MAX_STRING	CMDLINE_MAXLEN
#define CONFIG_BUFSIZE	512	/* input buffer size */

/*
 * maximum number of message files.
 *
 * main message= goes at entry 0, entries [1-12] are used for function keys
 *
 */
#define MAX_MESSAGES	13

typedef struct boot_image {
	struct boot_image *next;
	CHAR16	label[MAX_STRING];
	CHAR16	kname[FILENAME_MAXLEN];
	CHAR16  options[MAX_STRING];
	CHAR16	initrd[FILENAME_MAXLEN];
	CHAR16	root[FILENAME_MAXLEN];
	CHAR16	fallback[MAX_STRING];
	CHAR16	description[MAX_STRING];

	UINTN	ramdisk;
	UINTN	readonly;
	UINTN	literal;

	sys_img_options_t sys_img_opts;	/* architecture specific image options */
} boot_image_t;

typedef enum {
	TOK_ERR,
	TOK_EQUAL,
	TOK_STR,
	TOK_EOF
} token_t;

/*
 * global shared options
 * architecture specific global options are private to each architecture
 */
typedef struct {
	CHAR16		root[FILENAME_MAXLEN];	/* globally defined root fs */
	CHAR16		initrd[FILENAME_MAXLEN];/* globally defined initrd  */
	CHAR16		options[MAX_STRING];
	CHAR16		default_image_name[MAX_STRING];
	CHAR16		message_file[MAX_MESSAGES][FILENAME_MAXLEN]; 
	CHAR16		chooser[FILENAME_MAXLEN];/* which image chooser to use */
	CHAR16		config_file[FILENAME_MAXLEN];
	boot_image_t	*default_image;

	UINTN		readonly;

	/* 
	 * options that may affect global elilo options
	 */
	UINTN alt_check;
	UINTN debug;
	UINTN delay;
	UINTN prompt;
	UINTN timeout;
	UINTN verbose;
	UINTN edd30_no_force; /* don't force EDD30 if not set */
} global_config_t;

/*
 * structure used to point to a group of options.
 * Several group for the same category are supported via a linked list.
 */
typedef struct _config_option_group {
	struct _config_option_group	*next;	  /* pointer to next group */
	config_option_t			*options; /* the table of options for this group */
	UINTN				nentries; /* number of entries for this group */
} config_option_group_t;

static option_action_t do_image, do_literal, do_options;
static INTN check_verbosity(VOID *), check_chooser(VOID *);

static global_config_t global_config;	/* options shared by all images */

/*
 * Core global options: shared by all architectures, all modules
 */
static config_option_t global_common_options[]={
{OPT_STR,	OPT_GLOBAL, 	L"default",	NULL,		NULL,			global_config.default_image_name},
{OPT_NUM,	OPT_GLOBAL,	L"timeout",	NULL, 		NULL,			&global_config.timeout},
{OPT_NUM,	OPT_GLOBAL,	L"delay",	NULL,		NULL,			&global_config.delay},
{OPT_BOOL,	OPT_GLOBAL,	L"debug",	NULL,		NULL,			&global_config.debug},
{OPT_BOOL,	OPT_GLOBAL,	L"prompt",	NULL,		NULL,			&global_config.prompt},
{OPT_NUM,	OPT_GLOBAL,	L"verbose",	NULL,		check_verbosity,	&global_config.verbose},
{OPT_FILE,	OPT_GLOBAL,	L"root",	NULL,		NULL,			global_config.root},
{OPT_BOOL,	OPT_GLOBAL,	L"read-only",	NULL,		NULL,			&global_config.readonly},
{OPT_BOOL,	OPT_GLOBAL,	L"noedd30",	NULL,		NULL,			&global_config.edd30_no_force},
{OPT_CMD,	OPT_GLOBAL,	L"append",	NULL,		NULL,			global_config.options},
{OPT_FILE,	OPT_GLOBAL,	L"initrd",	NULL,		NULL,			global_config.initrd},
{OPT_FILE,	OPT_GLOBAL,	L"image",	do_image,	NULL,			opt_offsetof(kname)},
{OPT_BOOL,	OPT_GLOBAL,	L"checkalt",	NULL,		NULL,			&global_config.alt_check},
{OPT_STR,	OPT_GLOBAL,	L"chooser",	NULL,		check_chooser,		global_config.chooser},
{OPT_FILE,	OPT_GLOBAL,	L"message",	NULL,		NULL,			global_config.message_file[0]},
{OPT_FILE,	OPT_GLOBAL,	L"f1",		NULL,		NULL,			global_config.message_file[1]},
{OPT_FILE,	OPT_GLOBAL,	L"f2",		NULL,		NULL,			global_config.message_file[2]},
{OPT_FILE,	OPT_GLOBAL,	L"f3",		NULL,		NULL,			global_config.message_file[3]},
{OPT_FILE,	OPT_GLOBAL,	L"f4",		NULL,		NULL,			global_config.message_file[4]},
{OPT_FILE,	OPT_GLOBAL,	L"f5",		NULL,		NULL,			global_config.message_file[5]},
{OPT_FILE,	OPT_GLOBAL,	L"f6",		NULL,		NULL,			global_config.message_file[6]},
{OPT_FILE,	OPT_GLOBAL,	L"f7",		NULL,		NULL,			global_config.message_file[7]},
{OPT_FILE,	OPT_GLOBAL,	L"f8",		NULL,		NULL,			global_config.message_file[8]},
{OPT_FILE,	OPT_GLOBAL,	L"f9",		NULL,		NULL,			global_config.message_file[9]},
{OPT_FILE,	OPT_GLOBAL,	L"f10",		NULL,		NULL,			global_config.message_file[10]},
{OPT_FILE,	OPT_GLOBAL,	L"f11",		NULL,		NULL,			global_config.message_file[11]},
{OPT_FILE,	OPT_GLOBAL,	L"f12",		NULL,		NULL,			global_config.message_file[12]}
};

static config_option_t image_common_options[]={
    {OPT_FILE,	OPT_IMAGE,	L"root",	NULL,		NULL,	opt_offsetof(root)},
    {OPT_BOOL,	OPT_IMAGE,	L"read-only",	NULL,		NULL,	opt_offsetof(readonly)},
    {OPT_CMD,	OPT_IMAGE,	L"append",	do_options,	NULL,	opt_offsetof(options)},
    {OPT_CMD,	OPT_IMAGE,	L"literal",	do_literal,	NULL,	NULL},
    {OPT_FILE,	OPT_IMAGE,	L"initrd",	NULL,		NULL,	opt_offsetof(initrd)},
    {OPT_STR,	OPT_IMAGE,	L"label",	NULL,		NULL,	opt_offsetof(label)},
    {OPT_FILE,	OPT_IMAGE,	L"image",	do_image,	NULL,	opt_offsetof(kname)},
    {OPT_STR,	OPT_IMAGE,	L"description",	NULL,		NULL,	opt_offsetof(description)},
};

#define OPTION_IS_GLOBAL(p)	((p)->scope == OPT_GLOBAL)
#define OPTION_IS_IMG_SYS(p)	((p)->scope == OPT_IMAGE_SYS)

#define CHAR_EOF	(CHAR16)-1	/* Unicode version of EOF */
#define CHAR_NUM0	L'0'
#define CHAR_NUM9	L'9'

static UINTN line_num;
static INTN back; /* can go back by one char */

static config_option_group_t *global_option_list;
static config_option_group_t *image_option_list;


static config_option_group_t *current_options;

static boot_image_t *image_list, *first_image;
static boot_image_t *current_img;

static INT8 config_buf[CONFIG_BUFSIZE];	/* input buffer: file must be in ASCII! */
static UINTN buf_max, buf_pos;

static fops_fd_t config_fd;

static VOID 
config_error(CHAR16 *msg,...)
{
    va_list ap;
    extern UINTN _IPrint (UINTN, UINTN, SIMPLE_TEXT_OUTPUT_INTERFACE *, CHAR16 *, CHAR8 *, va_list);

    Print(L"near line %d: ",line_num);

    va_start(ap,msg);
    _IPrint((UINTN)-1, (UINTN)-1, systab->ConOut, msg, NULL, ap);
    va_end(ap);
    Print(L"\n");
}

/*
 * low level read routine
 * Return:
 *
 * Success:
 * 	- the next available unicode character
 * Error:
 * 	- CHAR_EOF : indicating error or EOF
 *
 * XXX: we suppose that the file is in ASCII format!
 */
static CHAR16
getc(VOID)
{
	EFI_STATUS status;

	if (buf_pos == 0 || buf_pos == buf_max) {
		buf_max = CONFIG_BUFSIZE;
		status = fops_read(config_fd, config_buf, &buf_max);
		if (EFI_ERROR(status) || buf_max == 0) return CHAR_EOF;

		buf_pos  = 0;
	}
	return (CHAR16)config_buf[buf_pos++];
}


/*
 * get the next unicode character with a one character
 * rewind buffer.
 */
static CHAR16
next(VOID)
{
    CHAR16 ch;

    if (back) {
	ch = back;
	back = 0;
	return ch;
    }
    return getc();
}

/*
 * rewind by one character
 */
static VOID
again(CHAR16 ch)
{
    if (back) { config_error(L"config: again invoked twice"); }
    back = ch;
}

/*
 * Look for matching option in the current group
 *
 * Return:
 * 	- pointer to option if found
 * 	- NULL if not found
 */
static config_option_t *
find_option(config_option_group_t *grp, CHAR16 *str)
{
	config_option_t *p = NULL;
	config_option_t *end;

	while(grp) {
		p = grp->options;
		end = grp->options+grp->nentries;

		while (p != end) {
			if (!StrCmp(str, p->name)) return p;
			p++;
		}
		grp = grp->next;
	}
	return NULL;
}

/*
 * main parser function
 * Return:
 * 	- a token code representing the kind of element found
 * 	- TOK_EOF: end-of-file (or error) detected
 * 	- TOK_STR: if string is found
 * 	- TOK_EQUAL: for the '=' sign
 * 	- TOK_ERR: in case of (parsing) error
 */
static token_t
get_token(CHAR16 *str, UINTN maxlen)
{
    INTN ch, escaped;
    CHAR16 *here;

    for (;;) {
	while ((ch = next()), ch == ' ' || ch == '\t' || ch == '\n') if (ch == '\n') line_num++;

	if (ch == CHAR_EOF) return TOK_EOF;

	if (ch != '#') break;

	/* skip comment line */
	while ((ch = next()), ch != '\n') if (ch == CHAR_EOF) return TOK_EOF;
	line_num++;
    }
    if (ch == '=') return TOK_EQUAL;

    if (ch == '"') {
	here = str;
	while (here-str < maxlen) {
	    if ((ch = next()) == CHAR_EOF) {
		    config_error(L"EOF in quoted string");
		    return TOK_ERR;
	    }
	    if (ch == '"') {
		*here = 0;
		return TOK_STR;
	    }
	    if (ch == '\\') {
		ch = next();
		if (ch != '"' && ch != '\\' && ch != '\n') {
		    config_error(L"Bad use of \\ in quoted string");
		    return TOK_ERR;
		}
		if (ch == '\n') continue;
#if 0
		    while ((ch = next()), ch == ' ' || ch == '\t');
		    if (!ch) continue;
		    again(ch);
		    ch = ' ';
		}
#endif
	    }
	    if (ch == '\n' || ch == '\t') {
		config_error(L"\\n and \\t are not allowed in quoted strings");
		return TOK_ERR;
	    }
	    *here++ = ch;
	}
	config_error(L"Quoted string is too long");
	return TOK_ERR;
    }

    here    = str;
    escaped = 0;

    while (here-str < maxlen) {
	if (escaped) {
	    if (ch == CHAR_EOF) {
		    config_error(L"\\ precedes EOF");
		    return TOK_ERR;
	    }
	    if (ch == '\n') line_num++;
	    else *here++ = ch == '\t' ? ' ' : ch;
	    escaped = 0;
	}
	else {
	    if (ch == ' ' || ch == '\t' || ch == '\n' || ch == '#' ||
	      ch == '=' || ch == CHAR_EOF) {
		again(ch);
		*here = 0;
		return TOK_STR;
	    }
	    if (!(escaped = (ch == '\\'))) *here++ = ch;
	}
	ch = next();
    }
    config_error(L"Token is too long");
    return TOK_ERR;
}

static INTN
image_check(boot_image_t *img)
{
	boot_image_t *b;

	if (img == NULL) return -1;

	/* do the obvious first */
	if (img->label[0] == '\0') {
		config_error(L"image has no label");
		return -1;
	}

	/* image_list points to the */
	for(b=image_list; b; b = b->next) {
		if (img == b) continue;
		if (!StrCmp(img->label, b->label)) {
			config_error(L"image with label %s already defined", img->label);
			return -1;
		}
	}
	return 0;
}

static INTN 
global_check(VOID)
{
	return 0;
}

static INTN
final_check(VOID)
{
	boot_image_t *b;

	if (global_config.default_image_name[0]) {
		for(b=image_list; b; b = b->next) {
			if (!StrCmp(b->label, global_config.default_image_name)) goto found;
		}
		config_error(L"default image '%s' not defined ", global_config.default_image_name);
		return -1;
	}
	global_config.default_image = first_image;
	return 0;
found:
	global_config.default_image = b;
	return 0;
}

/*
 * depending on the active set of options
 * adjust the option data pointer to:
 * if global option set:
 * 	- just the straight value from p->data
 * if image option set:
 * 	- adjust as offset to image
 * Return:
 * 	- the adjusted pointer
 */
static inline VOID *
adjust_pointer(config_option_t *p)
{
	/*
	 * adjust pointer
	 */
	if (OPTION_IS_GLOBAL(p)) return p->data;

	if (OPTION_IS_IMG_SYS(p)) return (VOID *)((UINTN)&current_img->sys_img_opts + p->data);

	return (VOID *)((UINTN)current_img + p->data);
}

/*
 * create a new image entry
 */
static INTN
do_image(config_option_t *p, VOID *str)
{
	boot_image_t *img;
	
	/*
	 * if we move to a new image from the current one
	 * then we need to check for validity of current.
	 *
	 * if this is the first image, then check the global
	 * options.
	 */
	if (current_img) {
		if (image_check(current_img) == -1) return -1;
	} else if (global_check() == -1) return -1;

	img = (boot_image_t *)alloc(sizeof(boot_image_t), EfiLoaderData);
	if (img == NULL) return -1;

	Memset(img, 0, sizeof(boot_image_t));

	DBG_PRT((L"must do image on %s", (CHAR16 *)str));

	/* copy kernel file name */
	StrCpy(img->kname, str);

	/* switch to image mode */
	current_options = image_option_list;

	/* keep track of first image in case no default is defined */
	if (image_list == NULL) first_image = img;

	/* append to end of image list, so when a chooser asks for the list
	 * it gets them in the order they were in in the config file
	 */
	if (image_list == NULL)
		image_list = img;
	else {
		boot_image_t * p = image_list;

		while (p->next)
			p = p->next;
		p->next = img;
	}

	/* update current image */
	current_img = img;

	return 0;
}

/*
 * by default all boolean options are defined
 * as false. This function sets the boolean
 * to true
 */
static INTN
do_boolean(config_option_t *p)
{
	INT8 *buf;

	buf = adjust_pointer(p);

	if (p->action) return p->action(p, NULL);

	/* set the field to true, overwrite if already defined */
	*buf = 1;

	return 0;
}
	
/*
 * the image option 'literal' requires special handling
 * because it overrides any defined option be it global or
 * local. so we use the option field and record the fact that
 * it should be interpreted as literal
 */
static INTN
do_literal(config_option_t *p, VOID *str)
{
	/*
	 * we know we have a valid current image at this point
	 */
	StrCpy(current_img->options, str);

	current_img->literal = 1;

	return 0;
}

static INTN
do_options(config_option_t *p, VOID *str)
{
	/* we ignore append if literal is already defined */
	if (current_img->literal) return 0;

	/*
	 * we know we have a valid current image at this point
	 */
	StrCpy(current_img->options, str);

	return 0;
}

static INTN
do_numeric(config_option_t *p)