Cole Dishington <Cole.Dishington@xxxxxxxxxxxxxxxxxxx> wrote:
> + /* Avoid applying nat->range to the reply direction */
> + if (!exp->dir || !nat->range_info.min_proto.all || !nat->range_info.max_proto.all) {
> + min = ntohs(exp->saved_proto.tcp.port);
> + range_size = 65535 - min + 1;
> + } else {
> + min = ntohs(nat->range_info.min_proto.all);
> + range_size = ntohs(nat->range_info.max_proto.all) - min + 1;
> + }
> +
> /* Try to get same port: if not, try to change it. */
> - for (port = ntohs(exp->saved_proto.tcp.port); port != 0; port++) {
> - int ret;
> + first_port = ntohs(exp->saved_proto.tcp.port);
> + if (min > first_port || first_port > (min + range_size - 1))
> + first_port = min;
>
> + for (i = 0, port = first_port; i < range_size; i++, port = (port - first_port + i) % range_size) {
This looks complicated. As far as I understand, this could instead be
written like this (not even compile tested):
/* Avoid applying nat->range to the reply direction */
if (!exp->dir || !nat->range_info.min_proto.all || !nat->range_info.max_proto.all) {
min = 1;
max = 65535;
range_size = 65535;
} else {
min = ntohs(nat->range_info.min_proto.all);
max = ntohs(nat->range_info.max_proto.all);
range_size = max - min + 1;
}
/* Try to get same port: if not, try to change it. */
port = ntohs(exp->saved_proto.tcp.port);
if (port < min || port > max)
port = min;
for (i = 0; i < range_size; i++) {
exp->tuple.dst.u.tcp.port = htons(port);
ret = nf_ct_expect_related(exp, 0);
if (ret != -EBUSY)
break;
port++;
if (port > max)
port = min;
}
if (ret != 0) {
...
AFAICS this is the same, we loop at most range_size times,
in case range_size is 64k, we will loop through all (hmmm,
not good actually, but better make that a different change)
else through given min - max range.
If orig port was in-range, we try it first, then increment.
If port exceeds upper bound, cycle back to min.
What do you think?
