passt/udp.h
David Gibson 480aa4a108 udp: Consistently use -1 to indicate un-opened sockets in maps
udp uses the udp_tap_map, udp_splice_ns and udp_splice_init tables to keep
track of already opened sockets bound to specific ports.  We need a way to
indicate entries where a socket hasn't been opened, but the code isn't
consistent if this is indicated by a 0 or a -1:
  * udp_splice_sendfrom() and udp_tap_handler() assume that 0 indicates
    an unopened socket
  * udp_sock_init() fills in -1 for a failure to open a socket
  * udp_timer_one() is somewhere in between, treating only strictly
    positive fds as valid

-1 (or, at least, negative) is really the correct choice here, since 0 is
a theoretically valid fd value (if very unlikely in practice).  Change to
use that consistently throughout.

The table does need to be initialised to all -1 values before any calls to
udp_sock_init() which can happen from conf_ports().  Because C doesn't make
it easy to statically initialise non zero values in large tables, this does
require a somewhat awkward call to initialise the table from conf().  This
is the best approach I could see for the short term, with any luck it will
go away at some point when those socket tables are replaced by a unified
flow table.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2023-11-07 09:55:03 +01:00

67 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_sock_handler(const struct ctx *c, union epoll_ref ref, uint32_t events,
const struct timespec *now);
int udp_tap_handler(struct ctx *c, uint8_t pif, int 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 *ts);
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
* @bound: Set if this file descriptor is a bound socket
* @splice: Set if descriptor packets to be "spliced"
* @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 splice:1,
orig:1,
v6:1;
};
uint32_t u32;
};
/**
* udp_port_fwd - UDP specific port forwarding configuration
* @f: Generic forwarding configuration
* @rdelta: Reversed delta map to translate source ports on return packets
*/
struct udp_port_fwd {
struct port_fwd 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_port_fwd fwd_in;
struct udp_port_fwd fwd_out;
struct timespec timer_run;
};
#endif /* UDP_H */