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/* dctrl-tools - Debian control file inspection tools
Copyright (C) 2003, 2004 Antti-Juhani Kaijanaho
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <ctype.h>
#include <stdlib.h>
#include <regex.h>
#include <string.h>
#include "fsaf.h"
#include "msg.h"
#include "util.h"
#include "predicate.h"
void init_predicate(struct predicate * p)
{
p->num_atoms = 0;
p->proglen = 0;
fieldtrie_init(&p->trie);
}
void addinsn(struct predicate * p, int insn)
{
if (insn == I_NOP) return;
if (p->proglen >= MAX_OPS) {
message(L_FATAL, "predicate is too complex", 0);
fail();
}
p->program[p->proglen++] = insn;
}
void predicate_finish_atom(struct predicate * p)
{
struct atom * atom = get_current_atom(p);
if (atom->field_name != 0) {
atom->field_inx = fieldtrie_insert(&p->trie, atom->field_name);
}
if (atom->mode == M_REGEX || atom->mode == M_EREGEX) {
int rerr = regcomp(&atom->regex, atom->pat,
(atom->mode == M_EREGEX ? REG_EXTENDED : 0)
| REG_NOSUB
| (atom->ignore_case ? REG_ICASE : 0));
if (rerr != 0) {
char * s;
s = get_regerror(rerr, &atom->regex);
if (s == 0) fatal_enomem(0);
message(L_FATAL, s, 0);
free(s);
fail();
}
}
}
static bool verify_atom(struct atom * atom, para_t * para)
{
size_t start, end;
if (atom->field_inx == -1) {
/* Take the full paragraph */
start = para->start;
end = para->end;
} else {
/* Take the field */
struct field_data * fd = ¶->fields[atom->field_inx];
start = fd->start;
end = fd->end;
}
size_t len = end - start;
struct fsaf_read_rv r = fsaf_read(para->fp, start, len);
assert(r.len == len);
switch (atom->mode) {
case M_EXACT:
if (len != atom->patlen) return false;
if (atom->ignore_case) {
return strncasecmp(atom->pat, r.b, len) == 0;
} else {
return strncmp(atom->pat, r.b, len) == 0;
}
case M_SUBSTR: {
#if 0
if (atom->ignore_case) {
return strncasestr(r.b, atom->pat, len);
} else {
return strnstr(r.b, atom->pat, len);
}
#else
bool rv;
char * s = strndup(r.b, len);
if (s == 0) fatal_enomem(0);
if (atom->ignore_case) {
rv = strcasestr(s, atom->pat) != 0;
} else {
rv = strstr(s, atom->pat) != 0;
}
free(s);
return rv;
#endif
}
case M_REGEX: case M_EREGEX: {
char * s = strndup(r.b, len);
if (s == 0) fatal_enomem(0);
int regex_errcode = regexec(&atom->regex, s, 0, 0, 0);
free(s);
if (regex_errcode == 0 || regex_errcode == REG_NOMATCH) {
return (regex_errcode == 0);
}
/* Error handling be here. */
assert(regex_errcode != 0 && regex_errcode != REG_NOMATCH);
s = get_regerror (regex_errcode, &atom->regex);
if (s == 0) { enomem (0); return false; }
message(L_IMPORTANT, s, 0);
free(s);
return false;
}
}
assert(0);
}
bool does_para_satisfy(struct predicate * p, para_t * para)
{
assert(para->trie == & p->trie);
bool sat_atom[MAX_ATOMS];
bool stack[MAX_OPS];
size_t sp = 0;
/* Verify atoms. */
for (size_t i = 0; i < p->num_atoms; i++) {
sat_atom[i] = verify_atom(&p->atoms[i], para);
}
/* Run the program. */
for (size_t i = 0; i < p->proglen; i++) {
switch (p->program[i]) {
case I_NOP: break;
case I_NEG:
assert(sp >= 1);
stack[sp-1] = !stack[sp-1];
break;
case I_AND:
assert(sp >= 2);
stack[sp-2] = stack[sp-2] && stack[sp-1];
--sp;
break;
case I_OR:
assert(sp >= 2);
stack[sp-2] = stack[sp-2] || stack[sp-1];
--sp;
break;
default:
{
int atom = p->program[i] - I_PUSH(0);
assert(atom <= p->num_atoms);
stack[sp] = sat_atom[atom];
++sp;
}
}
}
assert(sp == 1);
return stack[0];
}
|
