/*
* This function is recursive.. I wish I knew a nonrecursive way but
* I dont. anyway, recursion is fun.. :)
* DO NOT CALL THIS FUNTION WITH A POINTER TO A NULL POINTER
* (ie: If *elem is NULL, you're doing it wrong - seg fault)
*/
void crule_free(struct CRuleNode** elem)
{
int arg, numargs;
if ((*(elem))->funcptr == crule__not)
{
/* type conversions and ()'s are fun! ;) here have an asprin.. */
if ((*(elem))->arg[0] != NULL)
crule_free((struct CRuleNode**) &((*(elem))->arg[0]));
}
else if ((*(elem))->funcptr == crule__andor)
{
crule_free((struct CRuleNode**) &((*(elem))->arg[0]));
if ((*(elem))->arg[1] != NULL)
crule_free((struct CRuleNode**) &((*(elem))->arg[1]));
}
else
{
numargs = (*(elem))->numargs;
for (arg = 0; arg < numargs; arg++)
MyFree((*(elem))->arg[arg]);
}
#ifdef CR_DEBUG
fprintf(stderr, "freeing element at %ld\n", *elem);
#endif
MyFree(*elem);
*elem = 0;
}
/*
* Grammar
* rule:
* orexpr END END is end of input or :
* orexpr:
* andexpr
* andexpr || orexpr
* andexpr:
* primary
* primary && andexpr
* primary:
* function
* ! primary
* ( orexpr )
* function:
* word ( ) word is alphanumeric string, first character
* word ( arglist ) must be a letter
* arglist:
* word
* word , arglist
*/
struct CRuleNode* crule_parse(const char *rule)
{
const char* ruleptr = rule;
int next_tok;
struct CRuleNode* ruleroot = 0;
int errcode = CR_NOERR;
if ((errcode = crule_gettoken(&next_tok, &ruleptr)) == CR_NOERR) {
if ((errcode = crule_parseorexpr(&ruleroot, &next_tok, &ruleptr)) == CR_NOERR) {
if (ruleroot != NULL) {
if (next_tok == CR_END)
return (ruleroot);
else
errcode = CR_UNEXPCTTOK;
}
else
errcode = CR_EXPCTOR;
}
}
if (ruleroot != NULL)
crule_free(&ruleroot);
#if !defined(CR_DEBUG) && !defined(CR_CHKCONF)
Debug((DEBUG_ERROR, "%s in rule: %s", crule_errstr[errcode], rule));
#else
fprintf(stderr, "%s in rule: %s\n", crule_errstr[errcode], rule);
#endif
return 0;
}
/** Free all CRules from #cruleConfList. */
void conf_erase_crule_list(void)
{
struct CRuleConf* next;
struct CRuleConf* p = cruleConfList;
for ( ; p; p = next) {
next = p->next;
crule_free(&p->node);
MyFree(p->hostmask);
MyFree(p->rule);
MyFree(p);
}
cruleConfList = 0;
}
int main(void)
{
char indata[256];
CRuleNode* rule;
printf("rule: ");
while (fgets(indata, 256, stdin) != NULL)
{
indata[strlen(indata) - 1] = '\0'; /* lose the newline */
if ((rule = crule_parse(indata)) != NULL)
{
printf("equivalent rule: ");
print_tree((CRuleNodePtr) rule);
printf("\n");
crule_free(&rule);
}
printf("\nrule: ");
}
printf("\n");
return 0;
}
