diff options
Diffstat (limited to 'fwd.c')
| -rw-r--r-- | fwd.c | 47 |
1 files changed, 23 insertions, 24 deletions
@@ -358,8 +358,10 @@ static void procfs_scan_listen(int fd, unsigned int lstate, uint8_t *map) /** * fwd_scan_ports_tcp() - Scan /proc to update TCP forwarding map * @fwd: Forwarding information to update + * @rev: Forwarding information for the reverse direction */ -static void fwd_scan_ports_tcp(struct fwd_ports *fwd) +static void fwd_scan_ports_tcp(struct fwd_ports *fwd, + const struct fwd_ports *rev) { if (fwd->mode != FWD_AUTO) return; @@ -367,15 +369,20 @@ static void fwd_scan_ports_tcp(struct fwd_ports *fwd) memset(fwd->map, 0, PORT_BITMAP_SIZE); procfs_scan_listen(fwd->scan4, TCP_LISTEN, fwd->map); procfs_scan_listen(fwd->scan6, TCP_LISTEN, fwd->map); + bitmap_and_not(fwd->map, PORT_BITMAP_SIZE, fwd->map, rev->map); } /** * fwd_scan_ports_udp() - Scan /proc to update UDP forwarding map * @fwd: Forwarding information to update + * @rev: Forwarding information for the reverse direction * @tcp_fwd: Corresponding TCP forwarding information + * @tcp_rev: TCP forwarding information for the reverse direction */ static void fwd_scan_ports_udp(struct fwd_ports *fwd, - const struct fwd_ports *tcp_fwd) + const struct fwd_ports *rev, + const struct fwd_ports *tcp_fwd, + const struct fwd_ports *tcp_rev) { if (fwd->mode != FWD_AUTO) return; @@ -391,6 +398,14 @@ static void fwd_scan_ports_udp(struct fwd_ports *fwd, */ procfs_scan_listen(tcp_fwd->scan4, TCP_LISTEN, fwd->map); procfs_scan_listen(tcp_fwd->scan6, TCP_LISTEN, fwd->map); + + /* This means we need to skip numbers of TCP ports bound on the other + * side, too. Otherwise, we would detect corresponding UDP ports as + * bound and try to forward them from the opposite side, but it's + * already us handling them. + */ + bitmap_and_not(fwd->map, PORT_BITMAP_SIZE, fwd->map, rev->map); + bitmap_and_not(fwd->map, PORT_BITMAP_SIZE, fwd->map, tcp_rev->map); } /** @@ -399,28 +414,12 @@ static void fwd_scan_ports_udp(struct fwd_ports *fwd, */ static void fwd_scan_ports(struct ctx *c) { - fwd_scan_ports_tcp(&c->tcp.fwd_out); - fwd_scan_ports_tcp(&c->tcp.fwd_in); - fwd_scan_ports_udp(&c->udp.fwd_out, &c->tcp.fwd_out); - fwd_scan_ports_udp(&c->udp.fwd_in, &c->tcp.fwd_in); - - if (c->tcp.fwd_out.mode == FWD_AUTO) { - bitmap_and_not(c->tcp.fwd_out.map, PORT_BITMAP_SIZE, - c->tcp.fwd_out.map, c->tcp.fwd_in.map); - } - if (c->tcp.fwd_in.mode == FWD_AUTO) { - bitmap_and_not(c->tcp.fwd_in.map, PORT_BITMAP_SIZE, - c->tcp.fwd_in.map, c->tcp.fwd_out.map); - } - - if (c->udp.fwd_out.mode == FWD_AUTO) { - bitmap_and_not(c->udp.fwd_out.map, PORT_BITMAP_SIZE, - c->udp.fwd_out.map, c->udp.fwd_in.map); - } - if (c->udp.fwd_in.mode == FWD_AUTO) { - bitmap_and_not(c->udp.fwd_in.map, PORT_BITMAP_SIZE, - c->udp.fwd_in.map, c->udp.fwd_out.map); - } + fwd_scan_ports_tcp(&c->tcp.fwd_out, &c->tcp.fwd_in); + fwd_scan_ports_tcp(&c->tcp.fwd_in, &c->tcp.fwd_out); + fwd_scan_ports_udp(&c->udp.fwd_out, &c->udp.fwd_in, + &c->tcp.fwd_out, &c->tcp.fwd_in); + fwd_scan_ports_udp(&c->udp.fwd_in, &c->udp.fwd_out, + &c->tcp.fwd_in, &c->tcp.fwd_out); } /** |