OSPF: Allow ifaces with host address as unnumbered PtP or PtMP ifaces

Ifaces with host address (/32) were forced to be stubby, but now they
can be used as PtP or PtMP. For these ifaces we need to:

 - Do not force stub mode
 - Accept packets from any IP as local
 - Accept any configured neighbor as local
 - Detect ifaces properly as unnumbered
 - Use ONLINK flag for nexthops
This commit is contained in:
Ondrej Zajicek (work) 2021-05-10 13:39:55 +02:00
parent bc591061f6
commit 2a0af925b8
4 changed files with 30 additions and 16 deletions

View file

@ -529,14 +529,14 @@ add_nbma_node(struct ospf_iface *ifa, struct nbma_node *src, int found)
}
static int
ospf_iface_stubby(struct ospf_iface_patt *ip, struct ifa *addr)
ospf_iface_stubby(struct ospf_iface_patt *ip, struct ifa *addr, int type)
{
/* vlink cannot be stub */
if (ip->type == OSPF_IT_VLINK)
if (type == OSPF_IT_VLINK)
return 0;
/* a host address */
if (addr->flags & IA_HOST)
/* Host address on Broadcast/NBMA */
if (((type == OSPF_IT_BCAST) || (type == OSPF_IT_NBMA)) && (addr->flags & IA_HOST))
return 1;
/* a loopback iface */
@ -584,7 +584,6 @@ ospf_iface_new(struct ospf_area *oa, struct ifa *addr, struct ospf_iface_patt *i
ifa->strictnbma = ip->strictnbma;
ifa->waitint = ip->waitint;
ifa->deadint = ip->deadint;
ifa->stub = ospf_iface_stubby(ip, addr);
ifa->ioprob = OSPF_I_OK;
ifa->check_link = ip->check_link;
ifa->ecmp_weight = ip->ecmp_weight;
@ -598,18 +597,19 @@ ospf_iface_new(struct ospf_area *oa, struct ifa *addr, struct ospf_iface_patt *i
ifa->tx_length = ifa_tx_length(ifa);
ifa->tx_hdrlen = ifa_tx_hdrlen(ifa);
ifa->ptp_netmask = !(addr->flags & IA_PEER);
ifa->ptp_netmask = !(addr->flags & (IA_HOST | IA_PEER));
if (ip->ptp_netmask < 2)
ifa->ptp_netmask = ip->ptp_netmask;
/* For compatibility, we may use ptp_address even for unnumbered links */
ifa->ptp_address = !(addr->flags & IA_PEER) || (p->gr_mode != OSPF_GR_ABLE);
ifa->ptp_address = !(addr->flags & (IA_HOST | IA_PEER)) || (p->gr_mode != OSPF_GR_ABLE);
if (ip->ptp_address < 2)
ifa->ptp_address = ip->ptp_address;
ifa->drip = ifa->bdrip = ospf_is_v2(p) ? IPA_NONE4 : IPA_NONE6;
ifa->type = ospf_iface_classify(ip->type, addr);
ifa->stub = ospf_iface_stubby(ip, addr, ifa->type);
/* Check validity of interface type */
int old_type = ifa->type;
@ -647,7 +647,7 @@ ospf_iface_new(struct ospf_area *oa, struct ifa *addr, struct ospf_iface_patt *i
should be used). Because OSPFv3 iface is not subnet-specific,
there is no need for ipa_in_net() check */
if (ospf_is_v2(p) && !ipa_in_netX(nb->ip, &addr->prefix))
if (ospf_is_v2(p) && !ospf_ipa_local(nb->ip, addr))
continue;
if (ospf_is_v3(p) && !ipa_is_link_local(nb->ip))
@ -767,7 +767,7 @@ ospf_iface_reconfigure(struct ospf_iface *ifa, struct ospf_iface_patt *new)
if (old_type != new_type)
return 0;
int new_stub = ospf_iface_stubby(new, ifa->addr);
int new_stub = ospf_iface_stubby(new, ifa->addr, new_type);
if (ifa->stub != new_stub)
return 0;
@ -929,7 +929,7 @@ ospf_iface_reconfigure(struct ospf_iface *ifa, struct ospf_iface_patt *new)
WALK_LIST(nb, new->nbma_list)
{
/* See related note in ospf_iface_new() */
if (ospf_is_v2(p) && !ipa_in_netX(nb->ip, &ifa->addr->prefix))
if (ospf_is_v2(p) && !ospf_ipa_local(nb->ip, ifa->addr))
continue;
if (ospf_is_v3(p) && !ipa_is_link_local(nb->ip))
@ -1011,7 +1011,7 @@ ospf_iface_reconfigure(struct ospf_iface *ifa, struct ospf_iface_patt *new)
/* PtP netmask */
int new_ptp_netmask = (new->ptp_netmask < 2) ? new->ptp_netmask :
!(ifa->addr->flags & IA_PEER);
!(ifa->addr->flags & (IA_HOST | IA_PEER));
if (ifa->ptp_netmask != new_ptp_netmask)
{
OSPF_TRACE(D_EVENTS, "Changing PtP netmask option of %s from %d to %d",
@ -1021,7 +1021,7 @@ ospf_iface_reconfigure(struct ospf_iface *ifa, struct ospf_iface_patt *new)
/* PtP address */
int new_ptp_address = (new->ptp_address < 2) ? new->ptp_address :
(!(ifa->addr->flags & IA_PEER) || (p->gr_mode != OSPF_GR_ABLE));
(!(ifa->addr->flags & (IA_HOST | IA_PEER)) || (p->gr_mode != OSPF_GR_ABLE));
if (ifa->ptp_address != new_ptp_address)
{
/* Keep it silent for implicit changes */

View file

@ -946,6 +946,14 @@ struct lsadb_show_data {
#define EA_OSPF_ROUTER_ID EA_CODE(PROTOCOL_OSPF, 3)
/*
* For regular networks, neighbor address must match network prefix.
* For unnumbered networks, we consider every address local.
*/
static inline int ospf_ipa_local(ip_addr a, const struct ifa *addr)
{ return ipa_in_netX(a, &addr->prefix) || (addr->flags & IA_HOST); }
/* ospf.c */
void ospf_schedule_rtcalc(struct ospf_proto *p);

View file

@ -403,7 +403,7 @@ ospf_rx_hook(sock *sk, uint len)
return 1;
int src_local, dst_local, dst_mcast;
src_local = ipa_in_netX(sk->faddr, &ifa->addr->prefix);
src_local = ospf_ipa_local(sk->faddr, ifa->addr);
dst_local = ipa_equal(sk->laddr, ifa->addr->ip);
dst_mcast = ipa_equal(sk->laddr, ifa->all_routers) || ipa_equal(sk->laddr, ifa->des_routers);

View file

@ -1827,7 +1827,12 @@ calc_next_hop(struct ospf_area *oa, struct top_hash_entry *en,
return NULL;
}
return new_nexthop(p, nh, ifa->iface, ifa->ecmp_weight);
struct nexthop *nhs = new_nexthop(p, nh, ifa->iface, ifa->ecmp_weight);
if (ifa->addr->flags & IA_HOST)
nhs->flags = RNF_ONLINK;
return nhs;
}
/* The third case - bcast or nbma neighbor */
@ -2031,8 +2036,9 @@ again1:
for (nh = nf->n.nhs; nh; nh = nh->next)
if (ipa_nonzero(nh->gw))
{
neighbor *ng = neigh_find(&p->p, nh->gw, nh->iface, 0);
if (!ng || (ng->scope == SCOPE_HOST))
neighbor *nbr = neigh_find(&p->p, nh->gw, nh->iface,
(nh->flags & RNF_ONLINK) ? NEF_ONLINK : 0);
if (!nbr || (nbr->scope == SCOPE_HOST))
{ reset_ri(nf); break; }
}
}