258 	struct tcphdr *tcph = buf;  in fill_transportlayer()  local
260 	memset(tcph, 0, sizeof(*tcph));  in fill_transportlayer()
262 	tcph->source = htons(SPORT);  in fill_transportlayer()
263 	tcph->dest = htons(DPORT);  in fill_transportlayer()
264 	tcph->seq = ntohl(START_SEQ + seq_offset);  in fill_transportlayer()
265 	tcph->ack_seq = ntohl(START_ACK + ack_offset);  in fill_transportlayer()
266 	tcph->ack = 1;  in fill_transportlayer()
267 	tcph->fin = fin;  in fill_transportlayer()
268 	tcph->doff = 5;  in fill_transportlayer()
269 	tcph->window = htons(TCP_MAXWIN);  in fill_transportlayer()
270 	tcph->urg_ptr = 0;  in fill_transportlayer()
271 	tcph->check = tcp_checksum(tcph, payload_len);  in fill_transportlayer()
303 	struct tcphdr *tcph;  in send_flags()  local
311 	tcph = (struct tcphdr *)(flag_buf + tcp_offset);  in send_flags()
312 	tcph->psh = psh;  in send_flags()
313 	tcph->syn = syn;  in send_flags()
314 	tcph->rst = rst;  in send_flags()
315 	tcph->urg = urg;  in send_flags()
316 	tcph->check = 0;  in send_flags()
317 	tcph->check = tcp_checksum(tcph, payload_len);  in send_flags()
472 	struct tcphdr *tcph = (struct tcphdr *)(buf + tcp_offset);  in send_changed_checksum()  local
479 	tcph->check = tcph->check - 1;  in send_changed_checksum()
487 	struct tcphdr *tcph = (struct tcphdr *)(buf + tcp_offset);  in send_changed_seq()  local
494 	tcph->seq = ntohl(htonl(tcph->seq) + 1);  in send_changed_seq()
495 	tcph->check = 0;  in send_changed_seq()
496 	tcph->check = tcp_checksum(tcph, PAYLOAD_LEN);  in send_changed_seq()
748 	struct tcphdr *tcph;  in check_recv_pkts()  local
772 		tcph = (struct tcphdr *)(buffer + tcp_offset + ip_ext_len);  in check_recv_pkts()
774 		if (tcph->fin)  in check_recv_pkts()
777 		tcp_ext_len = (tcph->doff - 5) * 4;  in check_recv_pkts()