xref: /illumos-gate/usr/src/lib/gss_mechs/mech_krb5/profile/prof_parse.c (revision 159d09a2)

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */


#include "prof_int.h"

#include <stdio.h>
#include <string.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#include <errno.h>
#include <ctype.h>

#define SECTION_SEP_CHAR '/'

#define STATE_INIT_COMMENT	1
#define STATE_STD_LINE		2
#define STATE_GET_OBRACE	3

struct parse_state {
	int	state;
	int	group_level;
	struct profile_node *root_section;
	struct profile_node *current_section;
};

static char *skip_over_blanks(char *cp)
{
	while (*cp && isspace((int) (*cp)))
		cp++;
	return cp;
}

static void strip_line(char *line)
{
	char *p = line + strlen(line);
	while (p > line && (p[-1] == '\n' || p[-1] == '\r'))
	    *p-- = 0;
}

static void parse_quoted_string(char *str)
{
	char *to, *from;

	to = from = str;

	for (to = from = str; *from && *from != '"'; to++, from++) {
		if (*from == '\\') {
			from++;
			switch (*from) {
			case 'n':
				*to = '\n';
				break;
			case 't':
				*to = '\t';
				break;
			case 'b':
				*to = '\b';
				break;
			default:
				*to = *from;
			}
			continue;
		}
		*to = *from;
	}
	*to = '\0';
}


static errcode_t parse_init_state(struct parse_state *state)
{
	state->state = STATE_INIT_COMMENT;
	state->group_level = 0;

	return profile_create_node("(root)", 0, &state->root_section);
}

static errcode_t parse_std_line(char *line, struct parse_state *state)
{
	char	*cp, ch, *tag, *value;
	char	*p;
	errcode_t retval;
	struct profile_node	*node;
	int do_subsection = 0;
	void *iter = 0;

	if (*line == 0)
		return 0;
	cp = skip_over_blanks(line);
	if (cp[0] == ';' || cp[0] == '#')
		return 0;
	strip_line(cp);
	ch = *cp;
	if (ch == 0)
		return 0;
	if (ch == '[') {
		if (state->group_level > 0)
			return PROF_SECTION_NOTOP;
		cp++;
		p = strchr(cp, ']');
		if (p == NULL)
			return PROF_SECTION_SYNTAX;
		*p = '\0';
		retval = profile_find_node_subsection(state->root_section,
						 cp, &iter, 0,
						 &state->current_section);
		if (retval == PROF_NO_SECTION) {
			retval = profile_add_node(state->root_section,
						  cp, 0,
						  &state->current_section);
			if (retval)
				return retval;
		} else if (retval)
			return retval;

		/*
		 * Finish off the rest of the line.
		 */
		cp = p+1;
		if (*cp == '*') {
			profile_make_node_final(state->current_section);
			cp++;
		}
		/*
		 * A space after ']' should not be fatal
		 */
		cp = skip_over_blanks(cp);
		if (*cp)
			return PROF_SECTION_SYNTAX;
		return 0;
	}
	if (ch == '}') {
		if (state->group_level == 0)
			return PROF_EXTRA_CBRACE;
		if (*(cp+1) == '*')
			profile_make_node_final(state->current_section);
		retval = profile_get_node_parent(state->current_section,
						 &state->current_section);
		if (retval)
			return retval;
		state->group_level--;
		return 0;
	}
	/*
	 * Parse the relations
	 */
	tag = cp;
	cp = strchr(cp, '=');
	if (!cp)
		return PROF_RELATION_SYNTAX;
	if (cp == tag)
	    return PROF_RELATION_SYNTAX;
	*cp = '\0';
	p = tag;
	/* Look for whitespace on left-hand side.  */
	while (p < cp && !isspace((int)*p))
	    p++;
	if (p < cp) {
	    /* Found some sort of whitespace.  */
	    *p++ = 0;
	    /* If we have more non-whitespace, it's an error.  */
	    while (p < cp) {
		if (!isspace((int)*p))
		    return PROF_RELATION_SYNTAX;
		p++;
	    }
	}
	cp = skip_over_blanks(cp+1);
	value = cp;
	if (value[0] == '"') {
		value++;
		parse_quoted_string(value);
	} else if (value[0] == 0) {
		do_subsection++;
		state->state = STATE_GET_OBRACE;
	} else if (value[0] == '{' && *(skip_over_blanks(value+1)) == 0)
		do_subsection++;
	else {
		cp = value + strlen(value) - 1;
		while ((cp > value) && isspace((int) (*cp)))
			*cp-- = 0;
	}
	if (do_subsection) {
		p = strchr(tag, '*');
		if (p)
			*p = '\0';
		retval = profile_add_node(state->current_section,
					  tag, 0, &state->current_section);
		if (retval)
			return retval;
		if (p)
			profile_make_node_final(state->current_section);
		state->group_level++;
		return 0;
	}
	p = strchr(tag, '*');
	if (p)
		*p = '\0';
	profile_add_node(state->current_section, tag, value, &node);
	if (p)
		profile_make_node_final(node);
	return 0;
}

static errcode_t parse_line(char *line, struct parse_state *state)
{
	char	*cp;

	switch (state->state) {
	case STATE_INIT_COMMENT:
		if (line[0] != '[')
			return 0;
		state->state = STATE_STD_LINE;
		/*FALLTHRU*/
	case STATE_STD_LINE:
		return parse_std_line(line, state);
	case STATE_GET_OBRACE:
		cp = skip_over_blanks(line);
		if (*cp != '{')
			return PROF_MISSING_OBRACE;
		state->state = STATE_STD_LINE;
		/*FALLTHRU*/
	}
	return 0;
}

errcode_t profile_parse_file(FILE *f, struct profile_node **root)
{
#define BUF_SIZE	2048
	char *bptr;
	errcode_t retval;
	struct parse_state state;

	bptr = malloc (BUF_SIZE);
	if (!bptr)
		return ENOMEM;

	retval = parse_init_state(&state);
	if (retval) {
		free (bptr);
		return retval;
	}
	while (!feof(f)) {
		if (fgets(bptr, BUF_SIZE, f) == NULL)
			break;
#ifndef PROFILE_SUPPORTS_FOREIGN_NEWLINES
		retval = parse_line(bptr, &state);
		if (retval) {
			/* Solaris Kerberos: check if an unconfigured file */
			if (strstr(bptr, "___"))
				retval = PROF_NO_PROFILE;
			free (bptr);
			return retval;
		}
#else
		{
		    char *p, *end;

		    if (strlen(bptr) >= BUF_SIZE - 1) {
			/* The string may have foreign newlines and
			   gotten chopped off on a non-newline
			   boundary.  Seek backwards to the last known
			   newline.  */
			long offset;
			char *c = bptr + strlen (bptr);
			for (offset = 0; offset > -BUF_SIZE; offset--) {
			    if (*c == '\r' || *c == '\n') {
				*c = '\0';
				fseek (f, offset, SEEK_CUR);
				break;
			    }
			    c--;
			}
		    }