passt/udp.h
David Gibson b7ad19347f udp: Find or create flows for datagrams from tap interface
Currently we create flows for datagrams from socket interfaces, and use
them to direct "spliced" (socket to socket) datagrams.  We don't yet
match datagrams from the tap interface to existing flows, nor create new
flows for them.  Add that functionality, matching datagrams from tap to
existing flows when they exist, or creating new ones.

As with spliced flows, when creating a new flow from tap to socket, we
create a new connected socket to receive reply datagrams attached to that
flow specifically. We extend udp_flow_sock_handler() to handle reply
packets bound for tap rather than another socket.

For non-obvious reasons (perhaps increased stack usage?), this caused
a failure for me when running under valgrind, because valgrind invoked
rt_sigreturn which is not in our seccomp filter.  Since we already
allow rt_sigaction and others in the valgrind target, it seems
reasonable to add rt_sigreturn as well.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2024-07-19 18:33:48 +02:00

66 lines
2 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later
* Copyright (c) 2021 Red Hat GmbH
* Author: Stefano Brivio <sbrivio@redhat.com>
*/
#ifndef UDP_H
#define UDP_H
#define UDP_TIMER_INTERVAL 1000 /* ms */
void udp_portmap_clear(void);
void udp_buf_sock_handler(const struct ctx *c, union epoll_ref ref,
uint32_t events, const struct timespec *now);
void udp_reply_sock_handler(const struct ctx *c, union epoll_ref ref,
uint32_t events, const struct timespec *now);
int udp_tap_handler(const struct ctx *c, uint8_t pif,
sa_family_t af, const void *saddr, const void *daddr,
const struct pool *p, int idx, const struct timespec *now);
int udp_sock_init(const struct ctx *c, int ns, sa_family_t af,
const void *addr, const char *ifname, in_port_t port);
int udp_init(struct ctx *c);
void udp_timer(struct ctx *c, const struct timespec *now);
void udp_update_l2_buf(const unsigned char *eth_d, const unsigned char *eth_s);
/**
* union udp_epoll_ref - epoll reference portion for TCP connections
* @port: Source port for connected sockets, bound port otherwise
* @pif: pif for this socket
* @orig: Set if a spliced socket which can originate "connections"
* @v6: Set for IPv6 sockets or connections
* @u32: Opaque u32 value of reference
*/
union udp_epoll_ref {
struct {
in_port_t port;
uint8_t pif;
bool orig:1,
v6:1;
};
uint32_t u32;
};
/**
* udp_fwd_ports - UDP specific port forwarding configuration
* @f: Generic forwarding configuration
* @rdelta: Reversed delta map to translate source ports on return packets
*/
struct udp_fwd_ports {
struct fwd_ports f;
in_port_t rdelta[NUM_PORTS];
};
/**
* struct udp_ctx - Execution context for UDP
* @fwd_in: Port forwarding configuration for inbound packets
* @fwd_out: Port forwarding configuration for outbound packets
* @timer_run: Timestamp of most recent timer run
*/
struct udp_ctx {
struct udp_fwd_ports fwd_in;
struct udp_fwd_ports fwd_out;
struct timespec timer_run;
};
#endif /* UDP_H */