+static bool
+conntrack_addrcmp(const union nf_inet_addr *kaddr,
+ const union nf_inet_addr *uaddr,
+ const union nf_inet_addr *umask, unsigned int l3proto)
+{
+ if (l3proto == AF_INET)
+ return ((kaddr->ip ^ uaddr->ip) & umask->ip) == 0;
+ else if (l3proto == AF_INET6)
+ return ipv6_masked_addr_cmp(&kaddr->in6, &umask->in6,
+ &uaddr->in6) == 0;
+ else
+ return false;
+}
+
+static inline bool
+conntrack_mt_origsrc(const struct nf_conn *ct,
+ const struct xt_conntrack_mtinfo1 *info,
+ unsigned int family)
+{
+ return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3,
+ &info->origsrc_addr, &info->origsrc_mask, family);
+}
+
+static inline bool
+conntrack_mt_origdst(const struct nf_conn *ct,
+ const struct xt_conntrack_mtinfo1 *info,
+ unsigned int family)
+{
+ return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3,
+ &info->origdst_addr, &info->origdst_mask, family);
+}
+
+static inline bool
+conntrack_mt_replsrc(const struct nf_conn *ct,
+ const struct xt_conntrack_mtinfo1 *info,
+ unsigned int family)
+{
+ return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3,
+ &info->replsrc_addr, &info->replsrc_mask, family);
+}
+
+static inline bool
+conntrack_mt_repldst(const struct nf_conn *ct,
+ const struct xt_conntrack_mtinfo1 *info,
+ unsigned int family)
+{
+ return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3,
+ &info->repldst_addr, &info->repldst_mask, family);
+}
+
+static inline bool
+ct_proto_port_check(const struct xt_conntrack_mtinfo1 *info,
+ const struct nf_conn *ct)
+{
+ const struct nf_conntrack_tuple *tuple;
+
+ tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
+ if ((info->match_flags & XT_CONNTRACK_PROTO) &&
+ (nf_ct_protonum(ct) == info->l4proto) ^
+ !(info->invert_flags & XT_CONNTRACK_PROTO))
+ return false;
+
+ /* Shortcut to match all recognized protocols by using ->src.all. */
+ if ((info->match_flags & XT_CONNTRACK_ORIGSRC_PORT) &&
+ (tuple->src.u.all == info->origsrc_port) ^
+ !(info->invert_flags & XT_CONNTRACK_ORIGSRC_PORT))
+ return false;
+
+ if ((info->match_flags & XT_CONNTRACK_ORIGDST_PORT) &&
+ (tuple->dst.u.all == info->origdst_port) ^
+ !(info->invert_flags & XT_CONNTRACK_ORIGDST_PORT))
+ return false;
+
+ tuple = &ct->tuplehash[IP_CT_DIR_REPLY].tuple;
+
+ if ((info->match_flags & XT_CONNTRACK_REPLSRC_PORT) &&
+ (tuple->src.u.all == info->replsrc_port) ^
+ !(info->invert_flags & XT_CONNTRACK_REPLSRC_PORT))
+ return false;
+
+ if ((info->match_flags & XT_CONNTRACK_REPLDST_PORT) &&
+ (tuple->dst.u.all == info->repldst_port) ^
+ !(info->invert_flags & XT_CONNTRACK_REPLDST_PORT))
+ return false;
+
+ return true;
+}
+
+static bool
+conntrack_mt(const struct sk_buff *skb, const struct net_device *in,
+ const struct net_device *out, const struct xt_match *match,
+ const void *matchinfo, int offset, unsigned int protoff,
+ bool *hotdrop)
+{
+ const struct xt_conntrack_mtinfo1 *info = matchinfo;
+ enum ip_conntrack_info ctinfo;
+ const struct nf_conn *ct;
+ unsigned int statebit;
+
+ ct = nf_ct_get(skb, &ctinfo);
+
+ if (ct == &nf_conntrack_untracked)
+ statebit = XT_CONNTRACK_STATE_UNTRACKED;
+ else if (ct != NULL)
+ statebit = XT_CONNTRACK_STATE_BIT(ctinfo);
+ else
+ statebit = XT_CONNTRACK_STATE_INVALID;
+
+ if (info->match_flags & XT_CONNTRACK_STATE) {
+ if (ct != NULL) {
+ if (test_bit(IPS_SRC_NAT_BIT, &ct->status))
+ statebit |= XT_CONNTRACK_STATE_SNAT;
+ if (test_bit(IPS_DST_NAT_BIT, &ct->status))
+ statebit |= XT_CONNTRACK_STATE_DNAT;
+ }
+ if (!!(info->state_mask & statebit) ^
+ !(info->invert_flags & XT_CONNTRACK_STATE))
+ return false;
+ }
+
+ if (ct == NULL)
+ return info->match_flags & XT_CONNTRACK_STATE;
+ if ((info->match_flags & XT_CONNTRACK_DIRECTION) &&
+ (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) ^
+ !!(info->invert_flags & XT_CONNTRACK_DIRECTION))
+ return false;
+
+ if (info->match_flags & XT_CONNTRACK_ORIGSRC)
+ if (conntrack_mt_origsrc(ct, info, match->family) ^
+ !(info->invert_flags & XT_CONNTRACK_ORIGSRC))
+ return false;
+
+ if (info->match_flags & XT_CONNTRACK_ORIGDST)
+ if (conntrack_mt_origdst(ct, info, match->family) ^
+ !(info->invert_flags & XT_CONNTRACK_ORIGDST))
+ return false;
+
+ if (info->match_flags & XT_CONNTRACK_REPLSRC)
+ if (conntrack_mt_replsrc(ct, info, match->family) ^
+ !(info->invert_flags & XT_CONNTRACK_REPLSRC))
+ return false;
+
+ if (info->match_flags & XT_CONNTRACK_REPLDST)
+ if (conntrack_mt_repldst(ct, info, match->family) ^
+ !(info->invert_flags & XT_CONNTRACK_REPLDST))
+ return false;
+
+ if (!ct_proto_port_check(info, ct))
+ return false;
+
+ if ((info->match_flags & XT_CONNTRACK_STATUS) &&
+ (!!(info->status_mask & ct->status) ^
+ !(info->invert_flags & XT_CONNTRACK_STATUS)))
+ return false;
+
+ if (info->match_flags & XT_CONNTRACK_EXPIRES) {
+ unsigned long expires = 0;
+
+ if (timer_pending(&ct->timeout))
+ expires = (ct->timeout.expires - jiffies) / HZ;
+ if ((expires >= info->expires_min &&
+ expires <= info->expires_max) ^
+ !(info->invert_flags & XT_CONNTRACK_EXPIRES))
+ return false;
+ }
+ return true;
+}
+