int chain_rand(REMAILER *remailer, int badchains[MAXREM][MAXREM], int maxrem,
int thischain[], int chainlen, int t, int ignore_constraints_if_necessary)
/* set random chain. returns 0 if not random, 1 if random, -1 on error */
/* t... 0 for mixmaster Type II
* 1 for cypherpunk Type I
*/
{
int hop;
int err = 0;
int constraints_ignored = 0;
assert(t == 0 || t == 1);
start:
for (hop = 0; hop < chainlen; hop++)
if (thischain[hop] == 0) {
int select[MAXREM];
int randavail = 0;
int i;
err = 1;
if (hop > 0)
assert(thischain[hop-1]); /* we already should have chosen a remailer after this one */
for (i = 1; i < maxrem; i++) {
select[i] = ((remailer[i].flags.mix && t == 0) || /* remailer supports type */
(remailer[i].flags.pgp && remailer[i].flags.ek && t == 1)) &&
(remailer[i].info[t].reliability >= 100 * MINREL || constraints_ignored ) && /* remailer has sufficient reliability */
(remailer[i].info[t].latency <= MAXLAT || constraints_ignored ) && /* remailer has low enough latency */
(remailer[i].info[t].latency >= MINLAT || constraints_ignored ) && /* remailer has high enough latency */
!remailer[i].flags.star_ex && /* remailer is not excluded from random selection */
!badchains[i][0] && !badchains[i][thischain[hop-1]] && /* remailer can send to the next one */
(hop == chainlen-1 || !badchains[thischain[hop+1]][i]);
/* we are at the first hop or the previous one can send to this (may be random) */
randavail += select[i];
}
for (i = hop - DISTANCE; i <= hop + DISTANCE; i++)
if (i >= 0 && i < chainlen && select[thischain[i]] && thischain[i]) {
select[thischain[i]] = 0;
randavail--;
}
assert(randavail >= 0);
if (randavail < 1) {
if (ignore_constraints_if_necessary && !constraints_ignored) {
errlog(WARNING, "No reliable remailers. Ignoring for randhop\n");
constraints_ignored = 1;
goto start;
};
err = -1;
goto end;
}
do
thischain[hop] = rnd_number(maxrem - 1) + 1;
while (!select[thischain[hop]]);
}
end:
return (err);
}
int chain_randfinal(int type, REMAILER *remailer, int badchains[MAXREM][MAXREM], int maxrem, int rtype, int chain[], int chainlen, int ignore_constraints_if_necessary)
{
int randavail;
int i;
int t;
int select[MAXREM];
int secondtolasthop = (chainlen <= 1 ? -1 : chain[1]);
int constraints_ignored = 0;
t = rtype;
if (rtype == 2)
t = 1;
start:
randavail = 0;
/* select a random final hop */
for (i = 1; i < maxrem; i++) {
select[i] =
((remailer[i].flags.mix && rtype == 0) || /* remailer supports type */
(remailer[i].flags.pgp && remailer[i].flags.ek && rtype == 1) ||
(remailer[i].flags.newnym && rtype == 2)) &&
(remailer[i].info[t].reliability >= 100 * RELFINAL || constraints_ignored ) && /* remailer has sufficient reliability */
(remailer[i].info[t].latency <= MAXLAT || constraints_ignored ) && /* remailer has low enough latency */
(remailer[i].info[t].latency >= MINLAT || constraints_ignored ) && /* remailer has high enough latency */
(type == MSG_NULL || !remailer[i].flags.middle) && /* remailer is not middleman */
!remailer[i].flags.star_ex && /* remailer is not excluded from random selection */
(remailer[i].flags.post || type != MSG_POST) && /* remailer supports post when this is a post */
((secondtolasthop == -1) || !badchains[secondtolasthop][i]);
/* we only have hop or the previous one can send to this (may be random) */
randavail += select[i];
}
for (i = 1; i <= DISTANCE; i++)
if (i < chainlen && select[chain[i]] && chain[i]) {
select[chain[i]] = 0;
randavail--;
}
assert(randavail >= 0);
if (randavail == 0) {
if (ignore_constraints_if_necessary && !constraints_ignored) {
errlog(WARNING, "No reliable remailers. Ignoring for randhop\n");
constraints_ignored = 1;
goto start;
};
i = -1;
} else {
do
i = rnd_number(maxrem - 1) + 1;
while (!select[i]);
}
return (i);
}
system::Guess Randy::guess(const Game &game) const
{
auto &opp_hand = game.board.hands[system::Playsidetoi(system::invert(playside))];
// 入力
size_t place;
int number;
std::random_device rnd;
std::mt19937 mt(rnd());
std::uniform_int_distribution <> rnd_place(0, opp_hand.size() - 1);
while (true) {
place = rnd_place(mt);
if (!opp_hand[place].is_front) {
break;
}
}
std::uniform_int_distribution <> rnd_number(0, 11);
number = rnd_number(mt);
return system::Guess(place, number);
}
