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 
cil_parser(char * _path,char * buffer,uint32_t size,struct cil_tree ** parse_tree)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