1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
|
#include "util.h"
#include "string.h"
#include "strfilter.h"
/* Operators */
static const char *OP_and = "&"; /* Logical AND */
static const char *OP_or = "|"; /* Logical OR */
static const char *OP_not = "!"; /* Logical NOT */
#define is_operator(c) ((c) == '|' || (c) == '&' || (c) == '!')
#define is_separator(c) (is_operator(c) || (c) == '(' || (c) == ')')
static void strfilter_node__delete(struct strfilter_node *self)
{
if (self) {
if (self->p && !is_operator(*self->p))
free((char *)self->p);
strfilter_node__delete(self->l);
strfilter_node__delete(self->r);
free(self);
}
}
void strfilter__delete(struct strfilter *self)
{
if (self) {
strfilter_node__delete(self->root);
free(self);
}
}
static const char *get_token(const char *s, const char **e)
{
const char *p;
while (isspace(*s)) /* Skip spaces */
s++;
if (*s == '\0') {
p = s;
goto end;
}
p = s + 1;
if (!is_separator(*s)) {
/* End search */
retry:
while (*p && !is_separator(*p) && !isspace(*p))
p++;
/* Escape and special case: '!' is also used in glob pattern */
if (*(p - 1) == '\\' || (*p == '!' && *(p - 1) == '[')) {
p++;
goto retry;
}
}
end:
*e = p;
return s;
}
static struct strfilter_node *strfilter_node__alloc(const char *op,
struct strfilter_node *l,
struct strfilter_node *r)
{
struct strfilter_node *ret = zalloc(sizeof(struct strfilter_node));
if (ret) {
ret->p = op;
ret->l = l;
ret->r = r;
}
return ret;
}
static struct strfilter_node *strfilter_node__new(const char *s,
const char **ep)
{
struct strfilter_node root, *cur, *last_op;
const char *e;
if (!s)
return NULL;
memset(&root, 0, sizeof(root));
last_op = cur = &root;
s = get_token(s, &e);
while (*s != '\0' && *s != ')') {
switch (*s) {
case '&': /* Exchg last OP->r with AND */
if (!cur->r || !last_op->r)
goto error;
cur = strfilter_node__alloc(OP_and, last_op->r, NULL);
if (!cur)
goto nomem;
last_op->r = cur;
last_op = cur;
break;
case '|': /* Exchg the root with OR */
if (!cur->r || !root.r)
goto error;
cur = strfilter_node__alloc(OP_or, root.r, NULL);
if (!cur)
goto nomem;
root.r = cur;
last_op = cur;
break;
case '!': /* Add NOT as a leaf node */
if (cur->r)
goto error;
cur->r = strfilter_node__alloc(OP_not, NULL, NULL);
if (!cur->r)
goto nomem;
cur = cur->r;
break;
case '(': /* Recursively parses inside the parenthesis */
if (cur->r)
goto error;
cur->r = strfilter_node__new(s + 1, &s);
if (!s)
goto nomem;
if (!cur->r || *s != ')')
goto error;
e = s + 1;
break;
default:
if (cur->r)
goto error;
cur->r = strfilter_node__alloc(NULL, NULL, NULL);
if (!cur->r)
goto nomem;
cur->r->p = strndup(s, e - s);
if (!cur->r->p)
goto nomem;
}
s = get_token(e, &e);
}
if (!cur->r)
goto error;
*ep = s;
return root.r;
nomem:
s = NULL;
error:
*ep = s;
strfilter_node__delete(root.r);
return NULL;
}
/*
* Parse filter rule and return new strfilter.
* Return NULL if fail, and *ep == NULL if memory allocation failed.
*/
struct strfilter *strfilter__new(const char *rules, const char **err)
{
struct strfilter *ret = zalloc(sizeof(struct strfilter));
const char *ep = NULL;
if (ret)
ret->root = strfilter_node__new(rules, &ep);
if (!ret || !ret->root || *ep != '\0') {
if (err)
*err = ep;
strfilter__delete(ret);
ret = NULL;
}
return ret;
}
static bool strfilter_node__compare(struct strfilter_node *self,
const char *str)
{
if (!self || !self->p)
return false;
switch (*self->p) {
case '|': /* OR */
return strfilter_node__compare(self->l, str) ||
strfilter_node__compare(self->r, str);
case '&': /* AND */
return strfilter_node__compare(self->l, str) &&
strfilter_node__compare(self->r, str);
case '!': /* NOT */
return !strfilter_node__compare(self->r, str);
default:
return strglobmatch(str, self->p);
}
}
/* Return true if STR matches the filter rules */
bool strfilter__compare(struct strfilter *self, const char *str)
{
if (!self)
return false;
return strfilter_node__compare(self->root, str);
}
|
