udp: Use flags for local, loopback, and configured unicast binds

There's no value in keeping a separate timestamp for activity and for
aging of local binds, given that they have the same timeout. Reduce
that to a single timestamp, with a flag indicating the local bind.

Also use flags instead of separate int fields for loopback and
configured unicast address usage as source address.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
Stefano Brivio 2022-03-15 18:08:14 +01:00
parent 5ca555cf78
commit 79217b7689

48
udp.c
View file

@ -125,16 +125,16 @@
* struct udp_tap_port - Port tracking based on tap-facing source port
* @sock: Socket bound to source port used as index
* @ts: Activity timestamp from tap, used for socket aging
* @ts_local: Timestamp of tap packet to gateway address, aging for local bind
* @loopback: Whether local bind maps to loopback address as source
* @gua: Whether local bind maps to configured unicast address as source
* @flags: Flags for local bind, loopback address/unicast address as source
*/
struct udp_tap_port {
int sock;
time_t ts;
time_t ts_local;
int loopback;
int gua;
uint8_t flags;
#define PORT_LOCAL BIT(0)
#define PORT_LOOPBACK BIT(1)
#define PORT_GUA BIT(2)
};
/**
@ -684,12 +684,13 @@ static void udp_sock_fill_data_v4(struct ctx *c, int n, union epoll_ref ref,
if (src >> IN_CLASSA_NSHIFT == IN_LOOPBACKNET ||
src == INADDR_ANY || src == ntohl(c->addr4_seen)) {
b->iph.saddr = c->gw4;
udp_tap_map[V4][src_port].ts_local = now->tv_sec;
udp_tap_map[V4][src_port].ts = now->tv_sec;
udp_tap_map[V4][src_port].flags |= PORT_LOCAL;
if (b->s_in.sin_addr.s_addr == c->addr4_seen)
udp_tap_map[V4][src_port].loopback = 0;
udp_tap_map[V4][src_port].flags &= ~PORT_LOOPBACK;
else
udp_tap_map[V4][src_port].loopback = 1;
udp_tap_map[V4][src_port].flags |= PORT_LOOPBACK;
bitmap_set(udp_act[V4][UDP_ACT_TAP], src_port);
} else if (c->dns4_fwd &&
@ -768,17 +769,18 @@ static void udp_sock_fill_data_v6(struct ctx *c, int n, union epoll_ref ref,
else
b->ip6h.saddr = c->addr6_ll;
udp_tap_map[V6][src_port].ts_local = now->tv_sec;
udp_tap_map[V6][src_port].ts = now->tv_sec;
udp_tap_map[V6][src_port].flags |= PORT_LOCAL;
if (IN6_IS_ADDR_LOOPBACK(src))
udp_tap_map[V6][src_port].loopback = 1;
udp_tap_map[V6][src_port].flags |= PORT_LOOPBACK;
else
udp_tap_map[V6][src_port].loopback = 0;
udp_tap_map[V6][src_port].flags &= ~PORT_LOOPBACK;
if (IN6_ARE_ADDR_EQUAL(src, &c->addr6))
udp_tap_map[V6][src_port].gua = 1;
udp_tap_map[V6][src_port].flags |= PORT_GUA;
else
udp_tap_map[V6][src_port].gua = 0;
udp_tap_map[V6][src_port].flags &= ~PORT_GUA;
bitmap_set(udp_act[V6][UDP_ACT_TAP], src_port);
} else if (!IN6_IS_ADDR_UNSPECIFIED(&c->dns6_fwd) &&
@ -999,8 +1001,8 @@ int udp_tap_handler(struct ctx *c, int af, void *addr,
udp_tap_map[V4][src].ts = now->tv_sec;
if (s_in.sin_addr.s_addr == c->gw4 && !c->no_map_gw) {
if (!udp_tap_map[V4][dst].ts_local ||
udp_tap_map[V4][dst].loopback)
if (!(udp_tap_map[V4][dst].flags & PORT_LOCAL) ||
(udp_tap_map[V4][dst].flags & PORT_LOOPBACK))
s_in.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
else
s_in.sin_addr.s_addr = c->addr4_seen;
@ -1020,10 +1022,10 @@ int udp_tap_handler(struct ctx *c, int af, void *addr,
sl = sizeof(s_in6);
if (IN6_ARE_ADDR_EQUAL(addr, &c->gw6) && !c->no_map_gw) {
if (!udp_tap_map[V6][dst].ts_local ||
udp_tap_map[V6][dst].loopback)
if (!(udp_tap_map[V6][dst].flags & PORT_LOCAL) ||
(udp_tap_map[V6][dst].flags & PORT_LOOPBACK))
s_in6.sin6_addr = in6addr_loopback;
else if (udp_tap_map[V6][dst].gua)
else if (udp_tap_map[V6][dst].flags & PORT_GUA)
s_in6.sin6_addr = c->addr6;
else
s_in6.sin6_addr = c->addr6_seen;
@ -1241,13 +1243,9 @@ static void udp_timer_one(struct ctx *c, int v6, enum udp_act_type type,
case UDP_ACT_TAP:
tp = &udp_tap_map[v6 ? V6 : V4][port];
if (ts->tv_sec - tp->ts > UDP_CONN_TIMEOUT)
if (ts->tv_sec - tp->ts > UDP_CONN_TIMEOUT) {
s = tp->sock;
if (ts->tv_sec - tp->ts_local > UDP_CONN_TIMEOUT) {
tp->ts_local = 0;
tp->loopback = 0;
tp->gua = 0;
tp->flags = 0;
}
break;