/*
* Copyright (c) 2012 Elias Norberg <xyzzy@kudzu.se>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <xombrero.h>
#define TLD_TREE_END_NODE 1
#define TLD_TREE_EXCEPTION 2
struct tld_tree_node {
struct tld_tree_node *next;
struct tld_tree_node *child;
const char *lbl;
char flags;
};
struct tld_tree_node tld_tree_root = { NULL, NULL, "" };
#define TREE_INSERT_CHILD(n, data) \
n->child = g_malloc(sizeof *n); \
n->child->next = NULL; \
n->child->child = NULL; \
n->child->flags = 0; \
n->child->lbl = data;
#define TREE_INSERT_NEXT(n, data) \
n->next = g_malloc(sizeof *n); \
n->next->next = NULL; \
n->next->child = NULL; \
n->next->flags = 0; \
n->next->lbl = data;
#define P_BASE (36)
#define P_TMIN (1)
#define P_TMAX (26)
#define P_SKEW (38)
#define P_DAMP (700)
#define INITIAL_BIAS (72)
#define INITIAL_N (128)
int
adapt(int delta, int numpoints, int firsttime)
{
int k;
if (firsttime)
delta = delta / P_DAMP;
else
delta = delta / 2;
delta += (delta / numpoints);
k = 0;
while (delta > (((P_BASE - P_TMIN) * P_TMAX) / 2)) {
delta = delta / (P_BASE - P_TMIN);
k += P_BASE;
}
k += (((P_BASE - P_TMIN + 1) * delta) / (delta + P_SKEW));
return (k);
}
int
get_minimum_char(char *str, int n)
{
gunichar ch = 0;
gunichar min = 0xffffff;
for(; *str; str = g_utf8_next_char(str)) {
ch = g_utf8_get_char(str);
if (ch >= n && ch < min)
min = ch;
}
return (min);
}
char
encode_digit(int n)
{
if (n < 26)
return n + 'a';
return (n - 26) + '0';
}
char *
punycode_encode(char *str)
{
char output[1024];
char *s;
gunichar c;
int need_coding = 0;
int l, len, i;
int n = INITIAL_N;
int delta = 0;
int bias = INITIAL_BIAS;
int h, b, m, k, t, q;
l = 0;
for (s=str; *s; s = g_utf8_next_char(s)) {
c = g_utf8_get_char(s);
if (c < 128)
output[l++] = *s;
else
need_coding = 1;
}
output[l] = '\0';
if (!need_coding)
return g_strdup(output);
h = b = strlen(output);
if (l > 0)
output[l++] = '-';
output[l] = '\0';
len = g_utf8_strlen(str, -1);
while (h < len) {
m = get_minimum_char(str, n);
delta += (m - n) * (h + 1);
n = m;
for (s=str; *s; s = g_utf8_next_char(s)) {
c = g_utf8_get_char(s);
if (c < n) delta ++;
if (c == n) {
q = delta;
for (k=P_BASE;; k+=P_BASE) {
if (k <= bias)
t = P_TMIN;
else if(k >= bias + P_TMAX)
t = P_TMAX;
else
t = k - bias;
if (q < t)
break;
output[l++] = encode_digit(t+((q-t)%(P_BASE-t)));
q = (q - t) / (P_BASE - t);
}
output[l++] = encode_digit(q);
bias = adapt(delta, h + 1, h == b);
delta = 0;
h ++;
}
}
delta ++;
n ++;
}
output[l] = '\0';
for (i=l+4;i>=4;i--)
output[i] = output[i-4];
l += 4;
output[0] = 'x';
output[1] = 'n';
output[2] = '-';
output[3] = '-';
output[l] = '\0';
return g_strdup(output);
}
/*
* strrchr2(str, saveptr, ch)
*
* Walk backwards through str, jumping to next 'ch'
* On first call, *saveptr should be set to NULL.
* On following calls, supply the same saveptr.
*
* Returns NULL when the whole string 'str' has been
* looped through. Otherwise returns the position
* before the next 'ch'.
*/
const char *
strrchr2(const char *str, const char **saveptr, int ch)
{
const char *ptr;
if (str != NULL && *saveptr == NULL) {
*saveptr = str + strlen(str);
} else if (str == *saveptr) {
return (NULL);
}
for (ptr= *saveptr - 1; ptr != str && *ptr != ch; ptr--)
;
*saveptr = ptr;
if (ptr != str)
return (ptr+1);
return (ptr);
}
/*
* tld_tree_add(rule)
*
* Adds a tld-rule to the tree
*/
void
tld_tree_add(const char *rule)
{
struct tld_tree_node *n;
const char *lbl;
const char *saveptr;
saveptr = NULL;
lbl = strrchr2(rule, &saveptr, '.');
for (n = &tld_tree_root; lbl != NULL;) {
if (strcmp(n->lbl, lbl) == 0) {
lbl = strrchr2(rule, &saveptr, '.');
if (!n->child)
break;
n = n->child;
continue;
}
if (n->next == NULL) {
TREE_INSERT_NEXT(n, lbl);
n = n->next;
lbl = strrchr2(rule, &saveptr, '.');
break;
}
n = n->next;
}
while (lbl) {
TREE_INSERT_CHILD(n, lbl);
lbl = strrchr2(rule, &saveptr, '.');
n = n->child;
}
n->flags |= TLD_TREE_END_NODE;
if (n->lbl[0] == '!') {
n->flags |= TLD_TREE_EXCEPTION;
n->lbl ++;
}
}
void
tld_tree_init()
{
FILE *fd;
char buf[1024];
char file[PATH_MAX];
char *ptr, *next_lbl;
char *enc_lbl;
char *rule, *rp;
char extra_ch;
snprintf(file, sizeof file, "%s" PS "tld-rules", resource_dir);
fd = fopen(file, "r");
if (fd == NULL) {
/* a poor replacement for the real list - but it's
* better than nothing.
*/
tld_tree_add("*");
startpage_add("Could not open %s: this file is required "
"to handle TLD whitelisting properly", file);
return;
}
for (;;) {
ptr = fgets(buf, sizeof buf, fd);
if (ptr == NULL || feof(fd))
break;
/* skip comments */
if ((ptr = strstr(buf, "//")) != NULL)
*ptr = '\0';
/* skip anything after space or tab */
for (ptr = buf; *ptr; ptr++)
if (*ptr == ' ' || *ptr == '\t' ||
*ptr == '\n' || *ptr == '\r')
break;
*ptr = '\0';
if (!strlen(buf))
continue;
extra_ch = 0;
ptr = buf;
if (buf[0] == '!' && buf[0] == '*') {
extra_ch = buf[0];
ptr ++;
}
rule = NULL;
/* split into labels, and convert them one by one */
for (;;) {
if ((next_lbl = strchr(ptr, '.')))
*next_lbl = '\0';
enc_lbl = punycode_encode(ptr);
if (rule) {
rp = rule;
rule = g_strdup_printf("%s%s%s", rp, enc_lbl,
next_lbl ? "." : "");
g_free(rp);
g_free(enc_lbl);
} else {
rule = g_strdup_printf("%.1s%s%s",
extra_ch ? buf:"", enc_lbl,
next_lbl ? ".":"");
g_free(enc_lbl);
}
if (!next_lbl)
break;
ptr = next_lbl + 1;
}
tld_tree_add(rule);
}
fclose(fd);
}
/*
* tld_get_suffix(domain)
*
* Find the public suffix for domain.
*
* Returns a pointer to the suffix position
* in domain, or NULL if no public suffix
* was found.
*/
char *
tld_get_suffix(const char *domain)
{
struct tld_tree_node *n;
const char *suffix;
const char *lbl, *saveptr;
const char *tmp_saveptr, *tmp_lbl;
if (domain == NULL)
return (NULL);
if (domain[0] == '.')
return (NULL);
saveptr = NULL;
suffix = NULL;
lbl = strrchr2(domain, &saveptr, '.');
for (n = &tld_tree_root; n != NULL && lbl != NULL;) {
if (!strlen(n->lbl)) {
n = n->next;
continue;
}
if (n->lbl[0] == '*') {
if (n->flags & TLD_TREE_END_NODE) {
tmp_saveptr = saveptr;
tmp_lbl = lbl;
lbl = strrchr2(domain, &saveptr, '.');
/* Save possible public suffix */
suffix = lbl;
saveptr = tmp_saveptr;
lbl = tmp_lbl;
}
n = n->next;
continue;
}
if (strcmp(n->lbl, lbl) == 0) {
if (n->flags & TLD_TREE_EXCEPTION) {
/* We're done looking */
suffix = lbl;
break;
}
lbl = strrchr2(domain, &saveptr, '.');
/* Possible public suffix - other rules might
* still apply
*/
if (n->flags & TLD_TREE_END_NODE)
suffix = lbl;
/* Domain too short */
if (lbl == NULL) {
/* Check if we have a child that is '*' */
for (n = n->child; n; n = n->next)
if (n->lbl[0] == '*')
suffix = NULL;
break;
}
if (n->child == NULL)
break;
n = n->child;
continue;
}
if (n->next == NULL)
break;
n = n->next;
}
/* If we can't find a matching suffix, it can mean that either
* a) the user is surfing a local prefix
* b) the list is not properly updated
*
* In any case - in order not to break stuff while surfing
* new TLD's, we return the public suffix as the top 2 labels
*
* www.abc.xyz therefore has public suffix 'abc.xyz'
*/
if (!suffix) {
saveptr = NULL;
strrchr2(domain, &saveptr, '.');
lbl = strrchr2(domain, &saveptr, '.');
suffix = lbl;
}
return ((char*)suffix);
}