diff options
| -rw-r--r-- | net/openvswitch/conntrack.c | 103 |
1 files changed, 90 insertions, 13 deletions
diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c index a487bb3486e1..ae36fe2ed483 100644 --- a/net/openvswitch/conntrack.c +++ b/net/openvswitch/conntrack.c @@ -356,14 +356,101 @@ ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone, return __nf_ct_expect_find(net, zone, &tuple); } +/* This replicates logic from nf_conntrack_core.c that is not exported. */ +static enum ip_conntrack_info +ovs_ct_get_info(const struct nf_conntrack_tuple_hash *h) +{ + const struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h); + + if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) + return IP_CT_ESTABLISHED_REPLY; + /* Once we've had two way comms, always ESTABLISHED. */ + if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) + return IP_CT_ESTABLISHED; + if (test_bit(IPS_EXPECTED_BIT, &ct->status)) + return IP_CT_RELATED; + return IP_CT_NEW; +} + +/* Find an existing connection which this packet belongs to without + * re-attributing statistics or modifying the connection state. This allows an + * skb->nfct lost due to an upcall to be recovered during actions execution. + * + * Must be called with rcu_read_lock. + * + * On success, populates skb->nfct and skb->nfctinfo, and returns the + * connection. Returns NULL if there is no existing entry. + */ +static struct nf_conn * +ovs_ct_find_existing(struct net *net, const struct nf_conntrack_zone *zone, + u8 l3num, struct sk_buff *skb) +{ + struct nf_conntrack_l3proto *l3proto; + struct nf_conntrack_l4proto *l4proto; + struct nf_conntrack_tuple tuple; + struct nf_conntrack_tuple_hash *h; + enum ip_conntrack_info ctinfo; + struct nf_conn *ct; + unsigned int dataoff; + u8 protonum; + + l3proto = __nf_ct_l3proto_find(l3num); + if (!l3proto) { + pr_debug("ovs_ct_find_existing: Can't get l3proto\n"); + return NULL; + } + if (l3proto->get_l4proto(skb, skb_network_offset(skb), &dataoff, + &protonum) <= 0) { + pr_debug("ovs_ct_find_existing: Can't get protonum\n"); + return NULL; + } + l4proto = __nf_ct_l4proto_find(l3num, protonum); + if (!l4proto) { + pr_debug("ovs_ct_find_existing: Can't get l4proto\n"); + return NULL; + } + if (!nf_ct_get_tuple(skb, skb_network_offset(skb), dataoff, l3num, + protonum, net, &tuple, l3proto, l4proto)) { + pr_debug("ovs_ct_find_existing: Can't get tuple\n"); + return NULL; + } + + /* look for tuple match */ + h = nf_conntrack_find_get(net, zone, &tuple); + if (!h) + return NULL; /* Not found. */ + + ct = nf_ct_tuplehash_to_ctrack(h); + + ctinfo = ovs_ct_get_info(h); + if (ctinfo == IP_CT_NEW) { + /* This should not happen. */ + WARN_ONCE(1, "ovs_ct_find_existing: new packet for %p\n", ct); + } + skb->nfct = &ct->ct_general; + skb->nfctinfo = ctinfo; + return ct; +} + /* Determine whether skb->nfct is equal to the result of conntrack lookup. */ -static bool skb_nfct_cached(const struct net *net, const struct sk_buff *skb, - const struct ovs_conntrack_info *info) +static bool skb_nfct_cached(struct net *net, + const struct sw_flow_key *key, + const struct ovs_conntrack_info *info, + struct sk_buff *skb) { enum ip_conntrack_info ctinfo; struct nf_conn *ct; ct = nf_ct_get(skb, &ctinfo); + /* If no ct, check if we have evidence that an existing conntrack entry + * might be found for this skb. This happens when we lose a skb->nfct + * due to an upcall. If the connection was not confirmed, it is not + * cached and needs to be run through conntrack again. + */ + if (!ct && key->ct.state & OVS_CS_F_TRACKED && + !(key->ct.state & OVS_CS_F_INVALID) && + key->ct.zone == info->zone.id) + ct = ovs_ct_find_existing(net, &info->zone, info->family, skb); if (!ct) return false; if (!net_eq(net, read_pnet(&ct->ct_net))) @@ -396,7 +483,7 @@ static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key, * actually run the packet through conntrack twice unless it's for a * different zone. */ - if (!skb_nfct_cached(net, skb, info)) { + if (!skb_nfct_cached(net, key, info, skb)) { struct nf_conn *tmpl = info->ct; /* Associate skb with specified zone. */ @@ -459,18 +546,8 @@ static int ovs_ct_commit(struct net *net, struct sw_flow_key *key, const struct ovs_conntrack_info *info, struct sk_buff *skb) { - u8 state; int err; - state = key->ct.state; - if (key->ct.zone == info->zone.id && - ((state & OVS_CS_F_TRACKED) && !(state & OVS_CS_F_NEW))) { - /* Previous lookup has shown that this connection is already - * tracked and committed. Skip committing. - */ - return 0; - } - err = __ovs_ct_lookup(net, key, info, skb); if (err) return err; |