pf: fix synproxy to local

When we're synproxy-ing a connection that's going to us (as opposed to a
forwarded one) we wound up trying to send out the pf-generated tcp
packets through pf_intr(), which called ip(6)_output(). That doesn't
work all that well for packets that are destined for us, so in that case
we must call ip(6)_input() instead.

MFC after:	1 week
Sponsored by:   Modirum MDPay
Differential Revision:	https://reviews.freebsd.org/D31853
This commit is contained in:
Kristof Provost 2021-09-01 09:54:55 +02:00
parent 10eb2a2bde
commit 0a51d74c3a

View File

@ -1482,6 +1482,42 @@ pf_send(struct pf_send_entry *pfse)
swi_sched(V_pf_swi_cookie, 0);
}
static bool
pf_isforlocal(struct mbuf *m, int af)
{
switch (af) {
case AF_INET: {
struct rm_priotracker in_ifa_tracker;
struct ip *ip;
struct in_ifaddr *ia = NULL;
ip = mtod(m, struct ip *);
IN_IFADDR_RLOCK(&in_ifa_tracker);
LIST_FOREACH(ia, INADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr) {
IN_IFADDR_RUNLOCK(&in_ifa_tracker);
return (true);
}
}
IN_IFADDR_RUNLOCK(&in_ifa_tracker);
break;
}
case AF_INET6: {
struct ip6_hdr *ip6;
struct in6_ifaddr *ia;
ip6 = mtod(m, struct ip6_hdr *);
ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false);
if (ia == NULL)
return (false);
return (! (ia->ia6_flags & IN6_IFF_NOTREADY));
}
default:
panic("Unsupported af %d", af);
}
return (false);
}
void
pf_intr(void *v)
{
@ -1501,9 +1537,18 @@ pf_intr(void *v)
STAILQ_FOREACH_SAFE(pfse, &queue, pfse_next, next) {
switch (pfse->pfse_type) {
#ifdef INET
case PFSE_IP:
ip_output(pfse->pfse_m, NULL, NULL, 0, NULL, NULL);
case PFSE_IP: {
if (pf_isforlocal(pfse->pfse_m, AF_INET)) {
pfse->pfse_m->m_flags |= M_SKIP_FIREWALL;
pfse->pfse_m->m_pkthdr.csum_flags |=
CSUM_IP_VALID | CSUM_IP_CHECKED;
ip_input(pfse->pfse_m);
} else {
ip_output(pfse->pfse_m, NULL, NULL, 0, NULL,
NULL);
}
break;
}
case PFSE_ICMP:
icmp_error(pfse->pfse_m, pfse->icmpopts.type,
pfse->icmpopts.code, 0, pfse->icmpopts.mtu);
@ -1511,8 +1556,13 @@ pf_intr(void *v)
#endif /* INET */
#ifdef INET6
case PFSE_IP6:
ip6_output(pfse->pfse_m, NULL, NULL, 0, NULL, NULL,
NULL);
if (pf_isforlocal(pfse->pfse_m, AF_INET6)) {
pfse->pfse_m->m_flags |= M_SKIP_FIREWALL;
ip6_input(pfse->pfse_m);
} else {
ip6_output(pfse->pfse_m, NULL, NULL, 0, NULL,
NULL, NULL);
}
break;
case PFSE_ICMP6:
icmp6_error(pfse->pfse_m, pfse->icmpopts.type,
@ -2656,7 +2706,9 @@ pf_build_tcp(const struct pf_krule *r, sa_family_t af,
#endif /* ALTQ */
m->m_data += max_linkhdr;
m->m_pkthdr.len = m->m_len = len;
m->m_pkthdr.rcvif = NULL;
/* The rest of the stack assumes a rcvif, so provide one.
* This is a locally generated packet, so .. close enough. */
m->m_pkthdr.rcvif = V_loif;
bzero(m->m_data, len);
switch (af) {
#ifdef INET