static int
icmpv6_error_message(struct net *net, struct nf_conn *tmpl,
struct sk_buff *skb,
unsigned int icmp6off)
{
struct nf_conntrack_tuple intuple, origtuple;
const struct nf_conntrack_tuple_hash *h;
const struct nf_conntrack_l4proto *inproto;
enum ip_conntrack_info ctinfo;
struct nf_conntrack_zone tmp;
WARN_ON(skb_nfct(skb));
/* Are they talking about one of our connections? */
if (!nf_ct_get_tuplepr(skb,
skb_network_offset(skb)
+ sizeof(struct ipv6hdr)
+ sizeof(struct icmp6hdr),
PF_INET6, net, &origtuple)) {
pr_debug("icmpv6_error: Can't get tuple\n");
return -NF_ACCEPT;
}
/* rcu_read_lock()ed by nf_hook_thresh */
inproto = __nf_ct_l4proto_find(PF_INET6, origtuple.dst.protonum);
/* Ordinarily, we'd expect the inverted tupleproto, but it's
been preserved inside the ICMP. */
if (!nf_ct_invert_tuple(&intuple, &origtuple,
&nf_conntrack_l3proto_ipv6, inproto)) {
pr_debug("icmpv6_error: Can't invert tuple\n");
return -NF_ACCEPT;
}
ctinfo = IP_CT_RELATED;
h = nf_conntrack_find_get(net, nf_ct_zone_tmpl(tmpl, skb, &tmp),
&intuple);
if (!h) {
pr_debug("icmpv6_error: no match\n");
return -NF_ACCEPT;
} else {
if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
ctinfo += IP_CT_IS_REPLY;
}
/* Update skb to refer to this connection */
nf_ct_set(skb, nf_ct_tuplehash_to_ctrack(h), ctinfo);
return NF_ACCEPT;
}
static void
synproxy_send_client_synack(struct net *net,
const struct sk_buff *skb, const struct tcphdr *th,
const struct synproxy_options *opts)
{
struct sk_buff *nskb;
struct ipv6hdr *iph, *niph;
struct tcphdr *nth;
unsigned int tcp_hdr_size;
u16 mss = opts->mss;
iph = ipv6_hdr(skb);
tcp_hdr_size = sizeof(*nth) + synproxy_options_size(opts);
nskb = alloc_skb(sizeof(*niph) + tcp_hdr_size + MAX_TCP_HEADER,
GFP_ATOMIC);
if (nskb == NULL)
return;
skb_reserve(nskb, MAX_TCP_HEADER);
niph = synproxy_build_ip(net, nskb, &iph->daddr, &iph->saddr);
skb_reset_transport_header(nskb);
nth = (struct tcphdr *)skb_put(nskb, tcp_hdr_size);
nth->source = th->dest;
nth->dest = th->source;
nth->seq = htonl(__cookie_v6_init_sequence(iph, th, &mss));
nth->ack_seq = htonl(ntohl(th->seq) + 1);
tcp_flag_word(nth) = TCP_FLAG_SYN | TCP_FLAG_ACK;
if (opts->options & XT_SYNPROXY_OPT_ECN)
tcp_flag_word(nth) |= TCP_FLAG_ECE;
nth->doff = tcp_hdr_size / 4;
nth->window = 0;
nth->check = 0;
nth->urg_ptr = 0;
synproxy_build_options(nth, opts);
synproxy_send_tcp(net, skb, nskb, skb_nfct(skb),
IP_CT_ESTABLISHED_REPLY, niph, nth, tcp_hdr_size);
}
static void
synproxy_send_client_ack(struct net *net,
const struct sk_buff *skb, const struct tcphdr *th,
const struct synproxy_options *opts)
{
struct sk_buff *nskb;
struct iphdr *iph, *niph;
struct tcphdr *nth;
unsigned int tcp_hdr_size;
iph = ip_hdr(skb);
tcp_hdr_size = sizeof(*nth) + synproxy_options_size(opts);
nskb = alloc_skb(sizeof(*niph) + tcp_hdr_size + MAX_TCP_HEADER,
GFP_ATOMIC);
if (nskb == NULL)
return;
skb_reserve(nskb, MAX_TCP_HEADER);
niph = synproxy_build_ip(net, nskb, iph->saddr, iph->daddr);
skb_reset_transport_header(nskb);
nth = skb_put(nskb, tcp_hdr_size);
nth->source = th->source;
nth->dest = th->dest;
nth->seq = htonl(ntohl(th->seq) + 1);
nth->ack_seq = th->ack_seq;
tcp_flag_word(nth) = TCP_FLAG_ACK;
nth->doff = tcp_hdr_size / 4;
nth->window = htons(ntohs(th->window) >> opts->wscale);
nth->check = 0;
nth->urg_ptr = 0;
synproxy_build_options(nth, opts);
synproxy_send_tcp(net, skb, nskb, skb_nfct(skb),
IP_CT_ESTABLISHED_REPLY, niph, nth, tcp_hdr_size);
}
