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passt/icmp.h
Stefano Brivio f212044940 icmp: Don't discard first reply sequence for a given echo ID
In pasta mode, ICMP and ICMPv6 echo sockets relay back to us any
reply we send: we're on the same host as the target, after all. We
discard them by comparing the last sequence we sent with the sequence
we receive.

However, on the first reply for a given identifier, the sequence
might be zero, depending on the implementation of ping(8): we need
another value to indicate we haven't sent any sequence number, yet.

Use -1 as initialiser in the echo identifier map.

This is visible with Busybox's ping, and was reported by Paul on the
integration at https://github.com/containers/podman/pull/16141, with:

  $ podman run --net=pasta alpine ping -c 2 192.168.188.1

...where only the second reply would be routed back.

Reported-by: Paul Holzinger <pholzing@redhat.com>
Fixes: 33482d5bf2 ("passt: Add PASTA mode, major rework")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
2022-10-27 00:18:21 +02:00

43 lines
1.0 KiB
C

/* SPDX-License-Identifier: AGPL-3.0-or-later
* Copyright (c) 2021 Red Hat GmbH
* Author: Stefano Brivio <sbrivio@redhat.com>
*/
#ifndef ICMP_H
#define ICMP_H
#define ICMP_TIMER_INTERVAL 1000 /* ms */
struct ctx;
void icmp_sock_handler(const struct ctx *c, union epoll_ref ref,
uint32_t events, const struct timespec *now);
int icmp_tap_handler(const struct ctx *c, int af, const void *addr,
const struct pool *p, const struct timespec *now);
void icmp_timer(const struct ctx *c, const struct timespec *ts);
void icmp_init(void);
/**
* union icmp_epoll_ref - epoll reference portion for ICMP tracking
* @v6: Set for IPv6 sockets or connections
* @u32: Opaque u32 value of reference
* @id: Associated echo identifier, needed if bind() fails
*/
union icmp_epoll_ref {
struct {
uint32_t v6:1,
id:16;
} icmp;
uint32_t u32;
};
/**
* struct icmp_ctx - Execution context for ICMP routines
* @timer_run: Timestamp of most recent timer run
*/
struct icmp_ctx {
struct timespec timer_run;
};
#endif /* ICMP_H */