1 /*
2 * Copyright (c) 2008 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of the Institute nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #include "hx_locl.h"
35
36 struct hx_expr *
_hx509_make_expr(enum hx_expr_op op,void * arg1,void * arg2)37 _hx509_make_expr(enum hx_expr_op op, void *arg1, void *arg2)
38 {
39 struct hx_expr *expr;
40
41 expr = malloc(sizeof(*expr));
42 if (expr == NULL)
43 return NULL;
44 expr->op = op;
45 expr->arg1 = arg1;
46 expr->arg2 = arg2;
47
48 return expr;
49 }
50
51 static const char *
eval_word(hx509_context context,hx509_env env,struct hx_expr * word)52 eval_word(hx509_context context, hx509_env env, struct hx_expr *word)
53 {
54 switch (word->op) {
55 case expr_STRING:
56 return word->arg1;
57 case expr_VAR:
58 if (word->arg2 == NULL)
59 return hx509_env_find(context, env, word->arg1);
60
61 env = hx509_env_find_binding(context, env, word->arg1);
62 if (env == NULL)
63 return NULL;
64
65 return eval_word(context, env, word->arg2);
66 default:
67 return NULL;
68 }
69 }
70
71 static hx509_env
find_variable(hx509_context context,hx509_env env,struct hx_expr * word)72 find_variable(hx509_context context, hx509_env env, struct hx_expr *word)
73 {
74 assert(word->op == expr_VAR);
75
76 if (word->arg2 == NULL)
77 return hx509_env_find_binding(context, env, word->arg1);
78
79 env = hx509_env_find_binding(context, env, word->arg1);
80 if (env == NULL)
81 return NULL;
82 return find_variable(context, env, word->arg2);
83 }
84
85 static int
eval_comp(hx509_context context,hx509_env env,struct hx_expr * expr)86 eval_comp(hx509_context context, hx509_env env, struct hx_expr *expr)
87 {
88 switch (expr->op) {
89 case comp_NE:
90 case comp_EQ:
91 case comp_TAILEQ: {
92 const char *s1, *s2;
93 int ret;
94
95 s1 = eval_word(context, env, expr->arg1);
96 s2 = eval_word(context, env, expr->arg2);
97
98 if (s1 == NULL || s2 == NULL)
99 return FALSE;
100
101 if (expr->op == comp_TAILEQ) {
102 size_t len1 = strlen(s1);
103 size_t len2 = strlen(s2);
104
105 if (len1 < len2)
106 return 0;
107 ret = strcmp(s1 + (len1 - len2), s2) == 0;
108 } else {
109 ret = strcmp(s1, s2) == 0;
110 if (expr->op == comp_NE)
111 ret = !ret;
112 }
113 return ret;
114 }
115 case comp_IN: {
116 struct hx_expr *subexpr;
117 const char *w, *s1;
118
119 w = eval_word(context, env, expr->arg1);
120
121 subexpr = expr->arg2;
122
123 if (subexpr->op == expr_WORDS) {
124 while (subexpr) {
125 s1 = eval_word(context, env, subexpr->arg1);
126 if (strcmp(w, s1) == 0)
127 return TRUE;
128 subexpr = subexpr->arg2;
129 }
130 } else if (subexpr->op == expr_VAR) {
131 hx509_env subenv;
132
133 subenv = find_variable(context, env, subexpr);
134 if (subenv == NULL)
135 return FALSE;
136
137 while (subenv) {
138 if (subenv->type != env_string)
139 continue;
140 if (strcmp(w, subenv->name) == 0)
141 return TRUE;
142 if (strcmp(w, subenv->u.string) == 0)
143 return TRUE;
144 subenv = subenv->next;
145 }
146
147 } else
148 _hx509_abort("hx509 eval IN unknown op: %d", (int)subexpr->op);
149
150 return FALSE;
151 }
152 default:
153 _hx509_abort("hx509 eval expr with unknown op: %d", (int)expr->op);
154 }
155 return FALSE;
156 }
157
158 int
_hx509_expr_eval(hx509_context context,hx509_env env,struct hx_expr * expr)159 _hx509_expr_eval(hx509_context context, hx509_env env, struct hx_expr *expr)
160 {
161 switch (expr->op) {
162 case op_TRUE:
163 return 1;
164 case op_FALSE:
165 return 0;
166 case op_NOT:
167 return ! _hx509_expr_eval(context, env, expr->arg1);
168 case op_AND:
169 return _hx509_expr_eval(context, env, expr->arg1) &&
170 _hx509_expr_eval(context, env, expr->arg2);
171 case op_OR:
172 return _hx509_expr_eval(context, env, expr->arg1) ||
173 _hx509_expr_eval(context, env, expr->arg2);
174 case op_COMP:
175 return eval_comp(context, env, expr->arg1);
176 default:
177 _hx509_abort("hx509 eval expr with unknown op: %d", (int)expr->op);
178 UNREACHABLE(return 0);
179 }
180 }
181
182 void
_hx509_expr_free(struct hx_expr * expr)183 _hx509_expr_free(struct hx_expr *expr)
184 {
185 switch (expr->op) {
186 case expr_STRING:
187 case expr_NUMBER:
188 free(expr->arg1);
189 break;
190 case expr_WORDS:
191 case expr_FUNCTION:
192 case expr_VAR:
193 free(expr->arg1);
194 if (expr->arg2)
195 _hx509_expr_free(expr->arg2);
196 break;
197 default:
198 if (expr->arg1)
199 _hx509_expr_free(expr->arg1);
200 if (expr->arg2)
201 _hx509_expr_free(expr->arg2);
202 break;
203 }
204 free(expr);
205 }
206
207 struct hx_expr *
_hx509_expr_parse(const char * buf)208 _hx509_expr_parse(const char *buf)
209 {
210 _hx509_expr_input.buf = buf;
211 _hx509_expr_input.length = strlen(buf);
212 _hx509_expr_input.offset = 0;
213 _hx509_expr_input.expr = NULL;
214
215 if (_hx509_expr_input.error) {
216 free(_hx509_expr_input.error);
217 _hx509_expr_input.error = NULL;
218 }
219
220 yyparse();
221
222 return _hx509_expr_input.expr;
223 }
224
225 void
_hx509_sel_yyerror(const char * s)226 _hx509_sel_yyerror (const char *s)
227 {
228 if (_hx509_expr_input.error)
229 free(_hx509_expr_input.error);
230
231 _hx509_expr_input.error = strdup(s);
232 }
233
234