libpsl/src/psl.c

337 lines
7.6 KiB
C
Raw Normal View History

2014-03-20 22:43:04 +01:00
/*
* Copyright(c) 2014 Tim Ruehsen
*
* This file is part of MGet.
*
* Mget 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 3 of the License, or
* (at your option) any later version.
*
* Mget 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 Mget. If not, see <http://www.gnu.org/licenses/>.
*
*
* Public Suffix List routines (right now experimental)
*
* Changelog
* 19.03.2014 Tim Ruehsen created from libmget/cookie.c
*
*/
2014-03-21 11:05:09 +01:00
// need _GNU_SOURCE for qsort_r()
#ifndef _GNU_SOURCE
# define _GNU_SOURCE
#endif
2014-03-20 22:43:04 +01:00
#if HAVE_CONFIG_H
# include <config.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <libpsl.h>
#define countof(a) (sizeof(a)/sizeof(*(a)))
typedef struct {
char
label_buf[42];
const char *
label;
unsigned short
length;
unsigned char
nlabels, // number of labels
wildcard; // this is a wildcard rule (e.g. *.sapporo.jp)
} _psl_entry_t;
// stripped down version libmget vector routines
typedef struct {
int
(*cmp)(const _psl_entry_t *, const _psl_entry_t *); // comparison function
_psl_entry_t
**entry; // pointer to array of pointers to elements
int
max, // allocated elements
cur; // number of elements in use
} _psl_vector_t;
struct _psl_ctx_st {
_psl_vector_t
*suffixes,
*suffix_exceptions;
};
static _psl_vector_t *_vector_alloc(int max, int (*cmp)(const _psl_entry_t *, const _psl_entry_t *))
{
_psl_vector_t *v;
if (!(v = calloc(1, sizeof(_psl_vector_t))))
return NULL;
if (!(v->entry = malloc(max * sizeof(_psl_entry_t *)))) {
free(v);
return NULL;
}
v->max = max;
v->cmp = cmp;
return v;
}
static void _vector_free(_psl_vector_t **v)
{
if (v && *v) {
if ((*v)->entry) {
int it;
for (it = 0; it < (*v)->cur; it++)
free((*v)->entry[it]);
free((*v)->entry);
}
free(*v);
}
}
static _psl_entry_t *_vector_get(const _psl_vector_t *v, int pos)
{
if (pos < 0 || !v || pos >= v->cur) return NULL;
return v->entry[pos];
}
// the entries must be sorted by
static int _vector_find(const _psl_vector_t *v, const _psl_entry_t *elem)
{
if (v) {
int l, r, m;
int res;
// binary search for element (exact match)
for (l = 0, r = v->cur - 1; l <= r;) {
m = (l + r) / 2;
if ((res = v->cmp(elem, v->entry[m])) > 0) l = m + 1;
else if (res < 0) r = m - 1;
else return m;
}
}
return -1; // not found
}
static int _vector_add(_psl_vector_t *v, const _psl_entry_t *elem)
{
if (v) {
void *elemp;
elemp = malloc(sizeof(_psl_entry_t));
memcpy(elemp, elem, sizeof(_psl_entry_t));
if (v->max == v->cur)
v->entry = realloc(v->entry, (v->max *= 2) * sizeof(_psl_entry_t *));
v->entry[v->cur++] = elemp;
return v->cur - 1;
}
return -1;
}
static int _compare(const void *p1, const void *p2, void *v)
{
return ((_psl_vector_t *)v)->cmp(*((_psl_entry_t **)p1), *((_psl_entry_t **)p2));
}
static void _vector_sort(_psl_vector_t *v)
{
if (v && v->cmp)
qsort_r(v->entry, v->cur, sizeof(_psl_vector_t *), _compare, v);
}
// by this kind of sorting, we can easily see if a domain matches or not (match = supercookie !)
static int _suffix_compare(const _psl_entry_t *s1, const _psl_entry_t *s2)
{
int n;
if ((n = s2->nlabels - s1->nlabels))
return n; // most labels first
if ((n=s1->length - s2->length))
return n; // shorter rules first
return strcmp(s1->label, s2->label);
}
static void _suffix_init(_psl_entry_t *suffix, const char *rule, size_t length)
{
const char *src;
char *dst;
suffix->label = suffix->label_buf;
if (length >= sizeof(suffix->label_buf) - 1) {
suffix->nlabels = 0;
fprintf(stderr, _("Suffix rule too long (ignored): %s\n"), rule);
return;
}
if (*rule == '*') {
if (*++rule != '.') {
suffix->nlabels = 0;
fprintf(stderr, _("Unsupported kind of rule (ignored): %s\n"), rule);
return;
}
rule++;
suffix->wildcard = 1;
suffix->length = (unsigned char)length - 2;
} else {
suffix->wildcard = 0;
suffix->length = (unsigned char)length;
}
suffix->nlabels = 1;
for (dst = suffix->label_buf, src = rule; *src;) {
if (*src == '.')
suffix->nlabels++;
*dst++ = tolower(*src++);
}
*dst = 0;
}
int psl_is_tld(const psl_ctx_t *psl, const char *domain)
{
_psl_entry_t suffix, *rule;
const char *p, *label_bak;
unsigned short length_bak;
// this function should be called without leading dots, just make shure
suffix.label = domain + (*domain == '.');
suffix.length = strlen(suffix.label);
suffix.wildcard = 0;
suffix.nlabels = 1;
for (p = suffix.label; *p; p++)
if (*p == '.')
suffix.nlabels++;
// if domain has enough labels, it won't match
rule = _vector_get(psl->suffixes, 0);
if (!rule || rule->nlabels < suffix.nlabels - 1)
return 0;
rule = _vector_get(psl->suffixes, _vector_find(psl->suffixes, &suffix));
if (rule) {
// definitely a match, no matter if the found rule is a wildcard or not
return 1;
}
label_bak = suffix.label;
length_bak = suffix.length;
if ((suffix.label = strchr(suffix.label, '.'))) {
suffix.label++;
suffix.length = strlen(suffix.label);
suffix.nlabels--;
rule = _vector_get(psl->suffixes, _vector_find(psl->suffixes, &suffix));
if (rule) {
if (rule->wildcard) {
// now that we matched a wildcard, we have to check for an exception
suffix.label = label_bak;
suffix.length = length_bak;
suffix.nlabels++;
if (_vector_get(psl->suffix_exceptions, _vector_find(psl->suffix_exceptions, &suffix)) != 0)
return 0;
return 1;
}
}
}
return 0;
}
psl_ctx_t *psl_load_file(const char *fname)
{
psl_ctx_t *psl;
_psl_entry_t suffix, *suffixp;
FILE *fp;
int nsuffixes = 0;
char *buf = NULL, *linep, *p;
size_t bufsize = 0;
ssize_t buflen;
if (!(psl = calloc(1, sizeof(psl_ctx_t))))
return NULL;
// as of 02.11.2012, the list at http://publicsuffix.org/list/ contains ~6000 rules and 40 exceptions.
// as of 19.02.2014, the list at http://publicsuffix.org/list/ contains ~6500 rules and 19 exceptions.
psl->suffixes = _vector_alloc(8*1024, _suffix_compare);
psl->suffix_exceptions = _vector_alloc(64, _suffix_compare);
if ((fp = fopen(fname, "r"))) {
while ((buflen = getline(&buf, &bufsize, fp)) >= 0) {
linep = buf;
while (isspace(*linep)) linep++; // ignore leading whitespace
if (!*linep) continue; // skip empty lines
if (*linep == '/' && linep[1] == '/')
continue; // skip comments
// parse suffix rule
for (p = linep; *linep && !isspace(*linep);) linep++;
*linep = 0;
if (*p == '!') {
// add to exceptions
_suffix_init(&suffix, p + 1, linep - p - 1);
suffixp = _vector_get(psl->suffix_exceptions, _vector_add(psl->suffix_exceptions, &suffix));
} else {
_suffix_init(&suffix, p, linep - p);
suffixp = _vector_get(psl->suffixes, _vector_add(psl->suffixes, &suffix));
}
if (suffixp)
suffixp->label = suffixp->label_buf; // set label to changed address
nsuffixes++;;
}
free(buf);
fclose(fp);
_vector_sort(psl->suffix_exceptions);
_vector_sort(psl->suffixes);
printf("loaded %d (%d/%d) suffixes\n", nsuffixes, psl->suffixes->cur, psl->suffix_exceptions->cur);
} else
fprintf(stderr, _("Failed to open PSL file '%s'\n"), fname);
return psl;
}
void psl_free(psl_ctx_t **psl)
{
if (psl && *psl) {
_vector_free(&(*psl)->suffixes);
_vector_free(&(*psl)->suffix_exceptions);
free(*psl);
*psl = NULL;
}
}