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      1 /*
      2  * Copyright 2011 Tresys Technology, LLC. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions are met:
      6  *
      7  *    1. Redistributions of source code must retain the above copyright notice,
      8  *       this list of conditions and the following disclaimer.
      9  *
     10  *    2. Redistributions in binary form must reproduce the above copyright notice,
     11  *       this list of conditions and the following disclaimer in the documentation
     12  *       and/or other materials provided with the distribution.
     13  *
     14  * THIS SOFTWARE IS PROVIDED BY TRESYS TECHNOLOGY, LLC ``AS IS'' AND ANY EXPRESS
     15  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     16  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
     17  * EVENT SHALL TRESYS TECHNOLOGY, LLC OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
     18  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     19  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
     21  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
     22  * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     23  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  *
     25  * The views and conclusions contained in the software and documentation are those
     26  * of the authors and should not be interpreted as representing official policies,
     27  * either expressed or implied, of Tresys Technology, LLC.
     28  */
     29 
     30 #include <stdlib.h>
     31 #include <stdio.h>
     32 #include <string.h>
     33 #include <stdint.h>
     34 #include <sepol/errcodes.h>
     35 
     36 #include "cil_internal.h"
     37 #include "cil_log.h"
     38 #include "cil_mem.h"
     39 #include "cil_tree.h"
     40 #include "cil_lexer.h"
     41 #include "cil_strpool.h"
     42 
     43 int cil_parser(char *_path, char *buffer, uint32_t size, struct cil_tree **parse_tree)
     44 {
     45 
     46 	int paren_count = 0;
     47 
     48 	struct cil_tree *tree = NULL;
     49 	struct cil_tree_node *node = NULL;
     50 	struct cil_tree_node *item = NULL;
     51 	struct cil_tree_node *current = NULL;
     52 	char *path = cil_strpool_add(_path);
     53 
     54 	struct token tok;
     55 
     56 	cil_lexer_setup(buffer, size);
     57 
     58 	tree = *parse_tree;
     59 	current = tree->root;
     60 
     61 	do {
     62 		cil_lexer_next(&tok);
     63 		switch (tok.type) {
     64 		case OPAREN:
     65 			paren_count++;
     66 			cil_tree_node_init(&node);
     67 			node->parent = current;
     68 			node->flavor = CIL_NODE;
     69 			node->line = tok.line;
     70 			node->path = path;
     71 			if (current->cl_head == NULL) {
     72 				current->cl_head = node;
     73 			} else {
     74 				current->cl_tail->next = node;
     75 			}
     76 			current->cl_tail = node;
     77 			current = node;
     78 			break;
     79 		case CPAREN:
     80 			paren_count--;
     81 			if (paren_count < 0) {
     82 				cil_log(CIL_ERR, "Close parenthesis without matching open at line %d of %s\n", tok.line, path);
     83 				return SEPOL_ERR;
     84 			}
     85 			current = current->parent;
     86 			break;
     87 		case SYMBOL:
     88 		case QSTRING:
     89 			if (paren_count == 0) {
     90 				cil_log(CIL_ERR, "Symbol not inside parenthesis at line %d of %s\n", tok.line, path);
     91 				return SEPOL_ERR;
     92 			}
     93 			cil_tree_node_init(&item);
     94 			item->parent = current;
     95 			if (tok.type == QSTRING) {
     96 				tok.value[strlen(tok.value) - 1] = '\0';
     97 				item->data = cil_strpool_add(tok.value + 1);
     98 			} else {
     99 				item->data = cil_strpool_add(tok.value);
    100 			}
    101 			item->flavor = CIL_NODE;
    102 			item->line = tok.line;
    103 			item->path = path;
    104 			if (current->cl_head == NULL) {
    105 				current->cl_head = item;
    106 			} else {
    107 				current->cl_tail->next = item;
    108 			}
    109 			current->cl_tail = item;
    110 			break;
    111 		case END_OF_FILE:
    112 			if (paren_count > 0) {
    113 				cil_log(CIL_ERR, "Open parenthesis without matching close at line %d of %s\n", tok.line, path);
    114 				return SEPOL_ERR;
    115 			}
    116 			break;
    117 		case COMMENT:
    118 			// ignore
    119 			break;
    120 		case UNKNOWN:
    121 			cil_log(CIL_ERR, "Invalid token '%s' at line %d of %s\n", tok.value, tok.line, path);
    122 			return SEPOL_ERR;
    123 		default:
    124 			cil_log(CIL_ERR, "Unknown token type '%d' at line %d of %s\n", tok.type, tok.line, path);
    125 			return SEPOL_ERR;
    126 		}
    127 	}
    128 	while (tok.type != END_OF_FILE);
    129 
    130 	cil_lexer_destroy();
    131 
    132 	*parse_tree = tree;
    133 
    134 	return SEPOL_OK;
    135 }
    136