static struct ip_tunnel *ip_tunnel_find(struct ip_tunnel_net *itn, struct ip_tunnel_parm *parms, int type) { __be32 remote = parms->iph.daddr; __be32 local = parms->iph.saddr; __be32 key = parms->i_key; __be16 flags = parms->i_flags; int link = parms->link; struct ip_tunnel *t = NULL; struct hlist_head *head = ip_bucket(itn, parms); hlist_for_each_entry_rcu(t, head, hash_node) { if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr && link == t->parms.link && type == t->dev->type && ip_tunnel_key_match(&t->parms, flags, key)) break; } return t; }
/* Fallback tunnel: no source, no destination, no key, no options Tunnel hash table: We require exact key match i.e. if a key is present in packet it will match only tunnel with the same key; if it is not present, it will match only keyless tunnel. All keysless packets, if not matched configured keyless tunnels will match fallback tunnel. Given src, dst and key, find appropriate for input tunnel. */ struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn, int link, __be16 flags, __be32 remote, __be32 local, __be32 key) { unsigned int hash; struct ip_tunnel *t, *cand = NULL; struct hlist_head *head; hash = ip_tunnel_hash(itn, key, remote); head = &itn->tunnels[hash]; hlist_for_each_entry_rcu(t, head, hash_node) { if (local != t->parms.iph.saddr || remote != t->parms.iph.daddr || !(t->dev->flags & IFF_UP)) continue; if (!ip_tunnel_key_match(&t->parms, flags, key)) continue; if (t->parms.link == link) return t; else cand = t; } hlist_for_each_entry_rcu(t, head, hash_node) { if (remote != t->parms.iph.daddr || !(t->dev->flags & IFF_UP)) continue; if (!ip_tunnel_key_match(&t->parms, flags, key)) continue; if (t->parms.link == link) return t; else if (!cand) cand = t; } hash = ip_tunnel_hash(itn, key, 0); head = &itn->tunnels[hash]; hlist_for_each_entry_rcu(t, head, hash_node) { if ((local != t->parms.iph.saddr && (local != t->parms.iph.daddr || !ipv4_is_multicast(local))) || !(t->dev->flags & IFF_UP)) continue; if (!ip_tunnel_key_match(&t->parms, flags, key)) continue; if (t->parms.link == link) return t; else if (!cand) cand = t; } if (flags & TUNNEL_NO_KEY) goto skip_key_lookup; hlist_for_each_entry_rcu(t, head, hash_node) { if (t->parms.i_key != key || !(t->dev->flags & IFF_UP)) continue; if (t->parms.link == link) return t; else if (!cand) cand = t; } skip_key_lookup: if (cand) return cand; if (itn->fb_tunnel_dev && itn->fb_tunnel_dev->flags & IFF_UP) return netdev_priv(itn->fb_tunnel_dev); return NULL; }