conf: Fix initialisation of IPv6 unicast and link-local addresses

In commit 675174d4ba ("conf, tap: Split netlink and pasta
functions, allow interface configuration"), I broke the initial
setting of the observed IPv6 addresses in two ways:

- the size copied from the configured addresses corresponds to an
  IPv4 address, not to an IPv6 address

- the observed link-local address is initialised to the configured
  unicast address, not the link-local one

If we haven't seen the guest using some type of addresses yet, we
should default to the configured values, hence these initial
settings: fix both.

This resulted in UDP flows to the guest from a unique local address
on the network not working before the guest shows passt a valid
address itself, as reported by Alona.

Reported-by: Alona Paz <alkaplan@redhat.com>
Link: https://bugs.passt.top/show_bug.cgi?id=16
Fixes: 675174d4ba ("conf, tap: Split netlink and pasta functions, allow interface configuration")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
Stefano Brivio 2022-07-13 05:22:25 +02:00
parent f3198c4a06
commit 4de37151c9

4
conf.c
View file

@ -589,8 +589,8 @@ static void conf_ip(struct ctx *c)
IN6_IS_ADDR_UNSPECIFIED(&c->addr6) ? &c->addr6 : NULL,
&prefix_len, &c->addr6_ll);
memcpy(&c->addr6_seen, &c->addr6, sizeof(c->addr4_seen));
memcpy(&c->addr6_ll_seen, &c->addr6, sizeof(c->addr4_seen));
memcpy(&c->addr6_seen, &c->addr6, sizeof(c->addr6));
memcpy(&c->addr6_ll_seen, &c->addr6_ll, sizeof(c->addr6_ll));
}
if (!c->gw4 || !c->addr4 ||