Loading...
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 *node)
{
if (node) {
if (node->p && !is_operator(*node->p))
zfree((char **)&node->p);
strfilter_node__delete(node->l);
strfilter_node__delete(node->r);
free(node);
}
}
void strfilter__delete(struct strfilter *filter)
{
if (filter) {
strfilter_node__delete(filter->root);
free(filter);
}
}
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 *node = zalloc(sizeof(*node));
if (node) {
node->p = op;
node->l = l;
node->r = r;
}
return node;
}
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 *filter = zalloc(sizeof(*filter));
const char *ep = NULL;
if (filter)
filter->root = strfilter_node__new(rules, &ep);
if (!filter || !filter->root || *ep != '\0') {
if (err)
*err = ep;
strfilter__delete(filter);
filter = NULL;
}
return filter;
}
static bool strfilter_node__compare(struct strfilter_node *node,
const char *str)
{
if (!node || !node->p)
return false;
switch (*node->p) {
case '|': /* OR */
return strfilter_node__compare(node->l, str) ||
strfilter_node__compare(node->r, str);
case '&': /* AND */
return strfilter_node__compare(node->l, str) &&
strfilter_node__compare(node->r, str);
case '!': /* NOT */
return !strfilter_node__compare(node->r, str);
default:
return strglobmatch(str, node->p);
}
}
/* Return true if STR matches the filter rules */
bool strfilter__compare(struct strfilter *filter, const char *str)
{
if (!filter)
return false;
return strfilter_node__compare(filter->root, str);
}
|