369 	struct iphdr *ipv4;  member
386 		hdr->ipv4 = (void *)hdr->eth + sizeof(*hdr->eth);  in tcp_dissect()
387 		if (hdr->ipv4 + 1 > data_end)  in tcp_dissect()
389 		if (hdr->ipv4->ihl * 4 < sizeof(*hdr->ipv4))  in tcp_dissect()
391 		if (hdr->ipv4->version != 4)  in tcp_dissect()
394 		if (hdr->ipv4->protocol != IPPROTO_TCP)  in tcp_dissect()
397 		hdr->tcp = (void *)hdr->ipv4 + hdr->ipv4->ihl * 4;  in tcp_dissect()
400 		hdr->ipv4 = NULL;  in tcp_dissect()
440 	if (hdr->ipv4) {  in tcp_lookup()
444 		if ((hdr->ipv4->frag_off & bpf_htons(IP_MF | IP_OFFSET)) != 0)  in tcp_lookup()
447 		tup.ipv4.saddr = hdr->ipv4->saddr;  in tcp_lookup()
448 		tup.ipv4.daddr = hdr->ipv4->daddr;  in tcp_lookup()
449 		tup.ipv4.sport = hdr->tcp->source;  in tcp_lookup()
450 		tup.ipv4.dport = hdr->tcp->dest;  in tcp_lookup()
451 		tup_size = sizeof(tup.ipv4);  in tcp_lookup()
459 		/* The verifier can't track that either ipv4 or ipv6 is not  in tcp_lookup()
546 	swap(hdr->ipv4->saddr, hdr->ipv4->daddr);  in tcpv4_gen_synack()
547 	hdr->ipv4->check = 0; /* Calculate checksum later. */  in tcpv4_gen_synack()
548 	hdr->ipv4->tos = 0;  in tcpv4_gen_synack()
549 	hdr->ipv4->id = 0;  in tcpv4_gen_synack()
550 	hdr->ipv4->ttl = ttl;  in tcpv4_gen_synack()
555 	hdr->ipv4->tot_len = bpf_htons(sizeof(*hdr->ipv4) + hdr->tcp_len);  in tcpv4_gen_synack()
619 	if (hdr->ipv4) {  in syncookie_handle_syn()
620 		/* Check the IPv4 and TCP checksums before creating a SYNACK. */  in syncookie_handle_syn()
621 		value = bpf_csum_diff(0, 0, (void *)hdr->ipv4, hdr->ipv4->ihl * 4, 0);  in syncookie_handle_syn()
625 			return XDP_DROP; /* Bad IPv4 checksum. */  in syncookie_handle_syn()
630 		if (csum_tcpudp_magic(hdr->ipv4->saddr, hdr->ipv4->daddr,  in syncookie_handle_syn()
634 		ip_len = sizeof(*hdr->ipv4);  in syncookie_handle_syn()
636 		value = bpf_tcp_raw_gen_syncookie_ipv4(hdr->ipv4, hdr->tcp,  in syncookie_handle_syn()
670 	if (hdr->ipv4) {  in syncookie_handle_syn()
671 		if (hdr->ipv4->ihl * 4 > sizeof(*hdr->ipv4)) {  in syncookie_handle_syn()
674 			new_tcp_header = data + sizeof(*hdr->eth) + sizeof(*hdr->ipv4);  in syncookie_handle_syn()
678 			hdr->ipv4->ihl = sizeof(*hdr->ipv4) / 4;  in syncookie_handle_syn()
693 	if (hdr->ipv4) {  in syncookie_handle_syn()
694 		hdr->tcp->check = csum_tcpudp_magic(hdr->ipv4->saddr,  in syncookie_handle_syn()
695 						    hdr->ipv4->daddr,  in syncookie_handle_syn()
700 		hdr->ipv4->check = 0;  in syncookie_handle_syn()
701 		value = bpf_csum_diff(0, 0, (void *)hdr->ipv4, sizeof(*hdr->ipv4), 0);  in syncookie_handle_syn()
704 		hdr->ipv4->check = csum_fold(value);  in syncookie_handle_syn()
738 	if (hdr->ipv4)  in syncookie_handle_ack()
739 		err = bpf_tcp_raw_check_syncookie_ipv4(hdr->ipv4, hdr->tcp);  in syncookie_handle_ack()
790 	if (hdr->ipv4) {  in syncookie_part2()
792 		hdr->ipv4 = (void *)hdr->eth + sizeof(*hdr->eth);  in syncookie_part2()
796 		if ((void *)hdr->ipv4 + IPV4_MAXLEN > data_end)  in syncookie_part2()
798 		hdr->tcp = (void *)hdr->ipv4 + hdr->ipv4->ihl * 4;  in syncookie_part2()