net/netfilter/nf_synproxy_core.c

29 		       const struct tcphdr *th, struct synproxy_options *opts)
31 	int length = (th->doff * 4) - sizeof(*th);
37 	ptr = skb_header_pointer(skb, doff + sizeof(*th), length, buf);
115 synproxy_build_options(struct tcphdr *th, const struct synproxy_options *opts)
117 	__be32 *ptr = (__be32 *)(th + 1);
186 		       struct tcphdr *th, struct nf_conn *ct,
197 	optend = protoff + th->doff * 4;
229 				inet_proto_csum_replace4(&th->check, skb,
448 			    const struct sk_buff *skb, const struct tcphdr *th,
470 	nth->source	= th->dest;
471 	nth->dest	= th->source;
472 	nth->seq	= htonl(__cookie_v4_init_sequence(iph, th, &mss));
473 	nth->ack_seq	= htonl(ntohl(th->seq) + 1);
491 			 const struct sk_buff *skb, const struct tcphdr *th,
513 	nth->source	= th->source;
514 	nth->dest	= th->dest;
519 	nth->ack_seq	= htonl(ntohl(th->ack_seq) - 1);
524 	nth->window	= th->window;
537 			 const struct sk_buff *skb, const struct tcphdr *th,
558 	nth->source	= th->dest;
559 	nth->dest	= th->source;
560 	nth->seq	= htonl(ntohl(th->ack_seq));
561 	nth->ack_seq	= htonl(ntohl(th->seq) + 1);
575 			 const struct sk_buff *skb, const struct tcphdr *th,
596 	nth->source	= th->source;
597 	nth->dest	= th->dest;
598 	nth->seq	= htonl(ntohl(th->seq) + 1);
599 	nth->ack_seq	= th->ack_seq;
602 	nth->window	= htons(ntohs(th->window) >> opts->wscale);
614 			 const struct sk_buff *skb, const struct tcphdr *th,
620 	mss = __cookie_v4_check(ip_hdr(skb), th);
633 	synproxy_send_server_syn(net, skb, th, opts, recv_seq);
649 	struct tcphdr *th, _th;
665 	th = skb_header_pointer(skb, thoff, sizeof(_th), &_th);
666 	if (!th)
672 		if (th->rst && CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) {
674 						      ntohl(th->seq) + 1);
678 		if (!th->syn || th->ack ||
691 		if (!synproxy_parse_options(skb, thoff, th, &opts))
694 		if (!th->syn && th->ack &&
700 			if (synproxy_recv_client_ack(net, skb, th, &opts,
701 						     ntohl(th->seq) + 1)) {
710 		synproxy->isn = ntohl(th->ack_seq);
717 		if (!th->syn || !th->ack)
720 		if (!synproxy_parse_options(skb, thoff, th, &opts))
733 		synproxy_send_server_ack(net, state, skb, th, &opts);
735 		nf_ct_seqadj_init(ct, ctinfo, synproxy->isn - ntohl(th->seq));
739 		synproxy_send_client_ack(net, skb, th, &opts);
747 	synproxy_tstamp_adjust(skb, thoff, th, ct, ctinfo, synproxy);
861 				 const struct tcphdr *th,
883 	nth->source	= th->dest;
884 	nth->dest	= th->source;
885 	nth->seq	= htonl(nf_ipv6_cookie_init_sequence(iph, th, &mss));
886 	nth->ack_seq	= htonl(ntohl(th->seq) + 1);
905 			      const struct tcphdr *th,
927 	nth->source	= th->source;
928 	nth->dest	= th->dest;
933 	nth->ack_seq	= htonl(ntohl(th->ack_seq) - 1);
938 	nth->window	= th->window;
951 			      const struct tcphdr *th,
972 	nth->source	= th->dest;
973 	nth->dest	= th->source;
974 	nth->seq	= htonl(ntohl(th->ack_seq));
975 	nth->ack_seq	= htonl(ntohl(th->seq) + 1);
990 			      const struct tcphdr *th,
1011 	nth->source	= th->source;
1012 	nth->dest	= th->dest;
1013 	nth->seq	= htonl(ntohl(th->seq) + 1);
1014 	nth->ack_seq	= th->ack_seq;
1017 	nth->window	= htons(ntohs(th->window) >> opts->wscale);
1031 			      const struct tcphdr *th,
1037 	mss = nf_cookie_v6_check(ipv6_hdr(skb), th);
1050 	synproxy_send_server_syn_ipv6(net, skb, th, opts, recv_seq);
1066 	struct tcphdr *th, _th;
1088 	th = skb_header_pointer(skb, thoff, sizeof(_th), &_th);
1089 	if (!th)
1095 		if (th->rst && CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) {
1097 						      ntohl(th->seq) + 1);
1101 		if (!th->syn || th->ack ||
1114 		if (!synproxy_parse_options(skb, thoff, th, &opts))
1117 		if (!th->syn && th->ack &&
1123 			if (synproxy_recv_client_ack_ipv6(net, skb, th, &opts,
1124 							  ntohl(th->seq) + 1)) {
1133 		synproxy->isn = ntohl(th->ack_seq);
1140 		if (!th->syn || !th->ack)
1143 		if (!synproxy_parse_options(skb, thoff, th, &opts))
1156 		synproxy_send_server_ack_ipv6(net, state, skb, th, &opts);
1158 		nf_ct_seqadj_init(ct, ctinfo, synproxy->isn - ntohl(th->seq));
1162 		synproxy_send_client_ack_ipv6(net, skb, th, &opts);
1170 	synproxy_tstamp_adjust(skb, thoff, th, ct, ctinfo, synproxy);