diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index c2ad462f33f1..e4fd4f3a3cc7 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -1879,22 +1879,18 @@ static void nf_conntrack_attach(struct sk_buff *nskb, const struct sk_buff *skb) nf_conntrack_get(skb_nfct(nskb)); } -static int nf_conntrack_update(struct net *net, struct sk_buff *skb) +static int __nf_conntrack_update(struct net *net, struct sk_buff *skb, + struct nf_conn *ct) { struct nf_conntrack_tuple_hash *h; struct nf_conntrack_tuple tuple; enum ip_conntrack_info ctinfo; struct nf_nat_hook *nat_hook; unsigned int status; - struct nf_conn *ct; int dataoff; u16 l3num; u8 l4num; - ct = nf_ct_get(skb, &ctinfo); - if (!ct || nf_ct_is_confirmed(ct)) - return 0; - l3num = nf_ct_l3num(ct); dataoff = get_l4proto(skb, skb_network_offset(skb), l3num, &l4num); @@ -1951,6 +1947,76 @@ static int nf_conntrack_update(struct net *net, struct sk_buff *skb) return 0; } +/* This packet is coming from userspace via nf_queue, complete the packet + * processing after the helper invocation in nf_confirm(). + */ +static int nf_confirm_cthelper(struct sk_buff *skb, struct nf_conn *ct, + enum ip_conntrack_info ctinfo) +{ + const struct nf_conntrack_helper *helper; + const struct nf_conn_help *help; + unsigned int protoff; + + help = nfct_help(ct); + if (!help) + return 0; + + helper = rcu_dereference(help->helper); + if (!(helper->flags & NF_CT_HELPER_F_USERSPACE)) + return 0; + + switch (nf_ct_l3num(ct)) { + case NFPROTO_IPV4: + protoff = skb_network_offset(skb) + ip_hdrlen(skb); + break; +#if IS_ENABLED(CONFIG_IPV6) + case NFPROTO_IPV6: { + __be16 frag_off; + u8 pnum; + + pnum = ipv6_hdr(skb)->nexthdr; + protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &pnum, + &frag_off); + if (protoff < 0 || (frag_off & htons(~0x7)) != 0) + return 0; + break; + } +#endif + default: + return 0; + } + + if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) && + !nf_is_loopback_packet(skb)) { + if (!nf_ct_seq_adjust(skb, ct, ctinfo, protoff)) { + NF_CT_STAT_INC_ATOMIC(nf_ct_net(ct), drop); + return -1; + } + } + + /* We've seen it coming out the other side: confirm it */ + return nf_conntrack_confirm(skb) == NF_DROP ? - 1 : 0; +} + +static int nf_conntrack_update(struct net *net, struct sk_buff *skb) +{ + enum ip_conntrack_info ctinfo; + struct nf_conn *ct; + int err; + + ct = nf_ct_get(skb, &ctinfo); + if (!ct) + return 0; + + if (!nf_ct_is_confirmed(ct)) { + err = __nf_conntrack_update(net, skb, ct); + if (err < 0) + return err; + } + + return nf_confirm_cthelper(skb, ct, ctinfo); +} + static bool nf_conntrack_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple, const struct sk_buff *skb) {