passt/udp_flow.h
David Gibson 1166401c2f udp: Allow UDP flows to be prematurely closed
Unlike TCP, UDP has no in-band signalling for the end of a flow.  So the
only way we remove flows is on a timer if they have no activity for 180s.

However, we've started to investigate some error conditions in which we
want to prematurely abort / abandon a UDP flow.  We can call
udp_flow_close(), which will make the flow inert (sockets closed, no epoll
events, can't be looked up in hash).  However it will still wait 3 minutes
to clear away the stale entry.

Clean this up by adding an explicit 'closed' flag which will cause a flow
to be more promptly cleaned up.  We also publish udp_flow_close() so it
can be called from other places to abort UDP flows().

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-09-06 12:53:24 +02:00

40 lines
1.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later
* Copyright Red Hat
* Author: David Gibson <david@gibson.dropbear.id.au>
*
* UDP flow tracking data structures
*/
#ifndef UDP_FLOW_H
#define UDP_FLOW_H
/**
* struct udp - Descriptor for a flow of UDP packets
* @f: Generic flow information
* @closed: Flow is already closed
* @ts: Activity timestamp
* @s: Socket fd (or -1) for each side of the flow
*/
struct udp_flow {
/* Must be first element */
struct flow_common f;
bool closed :1;
time_t ts;
int s[SIDES];
};
struct udp_flow *udp_at_sidx(flow_sidx_t sidx);
flow_sidx_t udp_flow_from_sock(const struct ctx *c, union epoll_ref ref,
const union sockaddr_inany *s_in,
const struct timespec *now);
flow_sidx_t udp_flow_from_tap(const struct ctx *c,
uint8_t pif, sa_family_t af,
const void *saddr, const void *daddr,
in_port_t srcport, in_port_t dstport,
const struct timespec *now);
void udp_flow_close(const struct ctx *c, struct udp_flow *uflow);
bool udp_flow_defer(const struct udp_flow *uflow);
bool udp_flow_timer(const struct ctx *c, struct udp_flow *uflow,
const struct timespec *now);
#endif /* UDP_FLOW_H */