cfg.c

LINUX lilo-22.7.1 源代码。

static char *cfg_get_token(void)
{
    char buf[MAX_TOKEN+1];
    char *here;
    int ch,escaped;

    if (last_token) {
	here = last_token;
	last_token = NULL;
	return here;
    }
    while (1) {
	while ((ch = next()), ch == ' ' || ch == '\t' || ch == '\n')
	    if (ch == '\n') line_num++;
	if (ch == EOF) return NULL;
	if (ch != '#') break;
	while ((ch = next_raw()), ch != '\n')
	    if (ch == EOF) return NULL;
	line_num++;
    }
    if (ch == '=') return stralloc("=");
    if (ch == '"') {
	here = buf;
	while (here-buf < MAX_TOKEN) {
	    if ((ch = next()) == EOF) cfg_error("EOF in quoted string");
	    if (ch == '"') {
		*here = 0;
		return stralloc(buf);
	    }
	    if (ch == '\\') {
		ch = next();
		if (ch != '"' && ch != '\\' && ch != '\n')
		    cfg_error("Bad use of \\ in quoted string");
		if (ch == '\n') {
		    while ((ch = next()), ch == ' ' || ch == '\t');
		    if (!ch) continue;
		    again(ch);
		    ch = ' ';
		}
	    }
	    if (ch == '\n' || ch == '\t')
		cfg_error("\\n and \\t are not allowed in quoted strings");
	    *here++ = ch;
	}
	cfg_error("Quoted string is too long");
	return 0; /* not reached */
    }
    here = buf;
    escaped = 0;
    while (here-buf < MAX_TOKEN) {
	if (escaped) {
	    if (ch == EOF) cfg_error("\\ precedes EOF");
	    if (ch == '\n') line_num++;
	    else *here++ = ch == '\t' ? ' ' : ch;
	    escaped = 0;
	}
	else {
	    if (ch == ' ' || ch == '\t' || ch == '\n' || ch == '#' ||
	      ch == '=' || ch == EOF) {
		again(ch);
		*here = 0;
		return stralloc(buf);
	    }
#if !__MSDOS__
	    if (!(escaped = (ch == '\\')))
#endif /* !__MSDOS__ */
		*here++ = ch;
	}
	ch = next();
    }
    cfg_error("Token is too long");
    return 0; /* not reached */
}


static void cfg_return_token(char *token)
{
    last_token = token;
}


static int cfg_next(char **item,char **value)
{
    char *this;

    if (last_item) {
	*item = last_item;
	*value = last_value;
	last_item = NULL;
	return 1;
    }
    *value = NULL;
    if (!(*item = cfg_get_token())) return 0;
    if (!strcmp(*item,"=")) cfg_error("Syntax error");
    if (!(this = cfg_get_token())) return 1;
    if (strcmp(this,"=")) {
	cfg_return_token(this);
	return 1;
    }
    if (!(*value = cfg_get_token())) cfg_error("Value expected at EOF");
    if (!strcmp(*value,"=")) cfg_error("Syntax error after %s",*item);
    return 1;
}


static void cfg_return(char *item,char *value)
{
    last_item = item;
    last_value = value;
}


void cfg_init(CONFIG *table)
{
    while (table->type != cft_end) {
	switch (table->type) {
	    case cft_strg:
		if (table->data) free(table->data);
	    case cft_flag:
		table->data = NULL;
		break;
	    case cft_link:
		table = ((CONFIG *) table->action)-1;
		break;
	    default:
		die("Unknown syntax code %d",table->type);
	}
	table++;
    }
}


static int cfg_do_set(CONFIG *table,char *item,char *value,int copy,
    void *context)
{
    CONFIG *walk;

    for (walk = table; walk->type != cft_end; walk++) {
	if (walk->name && !strcasecmp(walk->name,item)) {
	    if (value && walk->type != cft_strg)
		cfg_error("'%s' doesn't have a value",walk->name);
	    if (!value && walk->type == cft_strg)
		cfg_error("Value expected for '%s'",walk->name);
	    if (walk->data) {
		if (walk->context == context)
		    cfg_error("Duplicate entry '%s'",walk->name);
		else {
		    fprintf(errstd,"Ignoring entry '%s'\n",walk->name);
		    if (!copy) free(value);
		    return 1;
		}
	    }
	    if (walk->type == cft_flag) walk->data = &flag_set;
	    else if (walk->type == cft_strg)
		    walk->data = copy ? stralloc(value) : value; 
	    walk->context = context;
	    if (walk->action) ((void (*)(void)) walk->action)();
	    break;
	}
	if (walk->type == cft_link) walk = ((CONFIG *) walk->action)-1;
    }
    if (walk->type != cft_end) return 1;
    cfg_return(item,value);
    return 0;
}


void cfg_set(CONFIG *table,char *item,char *value,void *context)
{
    if (cfg_do_set(table,item,value,1,context) != 1)
	cfg_error("cfg_set: Can't set %s",item);
}


void cfg_unset(CONFIG *table,char *item)
{
    CONFIG *walk;

    for (walk = table; walk->type != cft_end; walk++)
	if (walk->name && !strcasecmp(walk->name,item)) {
	    if (!walk->data) die("internal error (cfg_unset %s, unset)",item);
	    if (walk->type == cft_strg) free(walk->data);
	    walk->data = NULL;
	    return;
	}
    die("internal error (cfg_unset %s, unknown",item);
}

#if NEW_PARSE

static int cfg_end (char *item)
{
    CONFIG **key;
    CONFIG *c;

key = keywords;
while ((c = *key++)) {
    while (c->name) {
        if (!strcasecmp(c->name, item)) return 1;
        c++;
    }
}
    return 0;
}
#endif


int cfg_parse(CONFIG *table)
{
    char *item,*value;

    while (1) {
	if (!cfg_next(&item,&value)) return 0;
if(verbose>=6) printf("cfg_parse:  item=\"%s\" value=\"%s\"\n", item, value);
	if (!cfg_do_set(table,item,value,0,table)) {
#if NEW_PARSE==0
		return 1;
#else
	    if (cfg_end(item)) return 1;
	    else cfg_error("Unrecognized token \"%s\"", item);
#endif
	}
	free(item);
    }
}


int cfg_get_flag(CONFIG *table,char *item)
{
    CONFIG *walk;

    for (walk = table; walk->type != cft_end; walk++) {
	if (walk->name && !strcasecmp(walk->name,item)) {
	    if (walk->type != cft_flag)
		die("cfg_get_flag: operating on non-flag %s",item);
	    return !!walk->data;
	}
	if (walk->type == cft_link) walk = ((CONFIG *) walk->action)-1;
    }
    die("cfg_get_flag: unknown item %s",item);
    return 0; /* not reached */
}


char *cfg_get_strg(CONFIG *table,char *item)
{
    CONFIG *walk;

    for (walk = table; walk->type != cft_end; walk++) {
	if (walk->name && !strcasecmp(walk->name,item)) {
	    if (walk->type != cft_strg)
		die("cfg_get_strg: operating on non-string %s",item);
	    return walk->data;
	}
	if (walk->type == cft_link) walk = ((CONFIG *) walk->action)-1;
    }
    die("cfg_get_strg: unknown item %s",item);
    return 0; /* not reached */
}


#if !__MSDOS__
/* open the password file, passw=1 forces a new file to be created */

static char *pw_file_name;
FILE *pw_file = NULL;

FILE *cfg_pw_open(void)
{
    char name[MAX_TOKEN+1];
    struct stat buf;
    time_t conf;
    int fd;
    
    strcpy(name, file_name);	/* copy name of config file '/etc/lilo.conf' */
    strcat(name, PW_FILE_SUFFIX);
    pw_file_name = stralloc(name);
#if 1
    if (stat(file_name, &buf)) die("Cannot stat '%s'", file_name);
    conf = buf.st_mtime;
    if (!stat(pw_file_name, &buf) && conf>buf.st_mtime && !nowarn && !passw) {
        fprintf(errstd,"Warning: '%s' more recent than '%s'\n",
        	file_name, pw_file_name);
        fprintf(errstd," Running 'lilo -p' is recommended.\n");
    }
#endif    

    if (passw & !test) {
	if (unlink(pw_file_name) && errno != ENOENT) die("Could not delete '%s'", pw_file_name);
	if ((fd = creat(pw_file_name, 0600)) < 0) die("Could not create '%s'", pw_file_name);
	(void) close(fd);
	pw_file = fopen(pw_file_name, "w+");
    }
    else if (passw) return (pw_file=NULL);
    else {
        if (!(pw_file = fopen(pw_file_name, "r"))) {
            if (!test) {
                passw = 1;			/* force writing */
		if ((fd = creat(pw_file_name, 0600)) < 0) die("Could not create '%s'", pw_file_name);
		(void) close(fd);
                pw_file = fopen(pw_file_name, "w+");
            }
            else return (pw_file=NULL);
        }
    }
    if (!pw_file) die("Could not create '%s'", pw_file_name);
#if 1
    if (!stat(pw_file_name, &buf) && (buf.st_mode&0044) && !nowarn) {
        fprintf(errstd,"Warning: '%s' readable by other than 'root'\n",
        	pw_file_name);
    }
#endif    
    return pw_file;
}


/* allow only the "bitmap" keywords */

void cfg_bitmap_only(void)
{
    keywords[0] = cf_bitmap;
    keywords[1] = NULL;
}

#if BETA_TEST
void cfg_alpha_check(void)
{
    CONFIG **kw = keywords;
    CONFIG *cfg;
    
    while ((cfg=*kw)) {
	while (cfg[1].name) {
	    if (strcmp(cfg[0].name, cfg[1].name) >= 0) {
		die("cfg_alpha_check:  failure at '%s', '%s'", cfg[0].name, cfg[1].name);
	    }
	cfg++;
	}
    kw++;
    }
}
#endif

#endif /* !__MSDOS__ */