+void sendClose(int seq, u_int16_t ack_h, u_int32_t ack_l, int socket){
+ unsigned char buffer[1500];
+ struct dccp_hdr *dhdr;
+ struct dccp_hdr_ext *dhdre;
+ struct dccp_hdr_ack_bits *dhd_ack;
+ struct iphdr* ip4hdr;
+ struct ip6_hdr* ip6hdr;
+ int len;
+ int addrlen;
+
+ int ip_hdr_len;
+ int dccp_hdr_len=sizeof(struct dccp_hdr)+sizeof(struct dccp_hdr_ext)+sizeof(struct dccp_hdr_ack_bits);
+
+ memset(buffer, 0, 1500);
+
+ /*IP header*/
+ ip4hdr=NULL;
+ if(ip_type==AF_INET){
+ ip_hdr_len=sizeof(struct iphdr);
+ ip4hdr=(struct iphdr*)buffer;
+ ip4hdr->check=htons(0);
+ memcpy(&ip4hdr->daddr, &dest_addr.ipv4->sin_addr, sizeof(dest_addr.ipv4->sin_addr));
+ ip4hdr->frag_off=htons(0);
+ ip4hdr->id=htons(1);//first
+ ip4hdr->ihl=5;
+ ip4hdr->protocol=IPPROTO_DCCP;
+ memcpy(&ip4hdr->saddr, &src_addr.ipv4->sin_addr, sizeof(src_addr.ipv4->sin_addr));
+ ip4hdr->tos=0;
+ ip4hdr->tot_len=htons(ip_hdr_len+dccp_hdr_len);
+ ip4hdr->ttl=ttl;
+ ip4hdr->version=4;
+ }else{
+ ip_hdr_len=sizeof(struct ip6_hdr);
+ ip6hdr=(struct ip6_hdr*)buffer;
+ memcpy(&ip6hdr->ip6_dst, &dest_addr.ipv6->sin6_addr, sizeof(dest_addr.ipv6->sin6_addr));
+ memcpy(&ip6hdr->ip6_src, &src_addr.ipv6->sin6_addr, sizeof(src_addr.ipv6->sin6_addr));
+ ip6hdr->ip6_ctlun.ip6_un1.ip6_un1_flow=htonl(6<<28); //version, traffic class, flow label
+ ip6hdr->ip6_ctlun.ip6_un1.ip6_un1_hlim=ttl;
+ ip6hdr->ip6_ctlun.ip6_un1.ip6_un1_nxt=IPPROTO_DCCP;
+ ip6hdr->ip6_ctlun.ip6_un1.ip6_un1_plen=htons(dccp_hdr_len);
+ }
+
+ /*DCCP header*/
+ dhdr=(struct dccp_hdr*)(buffer+ip_hdr_len);
+ dhdre=(struct dccp_hdr_ext*)(buffer+ip_hdr_len+sizeof(struct dccp_hdr));
+ dhd_ack=(struct dccp_hdr_ack_bits*)(buffer+ip_hdr_len+sizeof(struct dccp_hdr)+sizeof(struct dccp_hdr_ext));
+ dhdr->dccph_ccval=0;
+ dhdr->dccph_checksum=0;
+ dhdr->dccph_cscov=0;
+ dhdr->dccph_doff=dccp_hdr_len/4;
+ dhdr->dccph_dport=htons(dest_port);
+ dhdr->dccph_reserved=0;
+ dhdr->dccph_sport=htons(dest_port);
+ dhdr->dccph_x=1;
+ dhdr->dccph_type=DCCP_PKT_CLOSE;
+ dhdr->dccph_seq2=htonl(0); //Reserved if using 48 bit sequence numbers
+ dhdr->dccph_seq=htonl(0); //High 16bits of sequence number. Always make 0 for simplicity.
+ dhdre->dccph_seq_low=htonl(seq+1);
+ dhd_ack->dccph_ack_nr_high=ack_h;
+ dhd_ack->dccph_ack_nr_low=ack_l;
+
+ /*Checksums*/
+ if(ip_type==AF_INET){
+ dhdr->dccph_checksum=ipv4_pseudohdr_chksum((buffer+ip_hdr_len), dccp_hdr_len,
+ (unsigned char*) &dest_addr.ipv4->sin_addr,
+ (unsigned char*)&src_addr.ipv4->sin_addr, IPPROTO_DCCP);
+ ip4hdr->check=ipv4_chksum(buffer,ip_hdr_len);
+ }else{
+ dhdr->dccph_checksum=ipv6_pseudohdr_chksum((buffer+ip_hdr_len), dccp_hdr_len,
+ (unsigned char*) &dest_addr.ipv6->sin6_addr,
+ (unsigned char*)&src_addr.ipv6->sin6_addr, IPPROTO_DCCP);
+ }
+ len=ip_hdr_len+dccp_hdr_len;
+
+ /*Send*/
+ if(ip_type==AF_INET){
+ addrlen=sizeof(struct sockaddr_in);
+ }else{
+ addrlen=sizeof(struct sockaddr_in6);
+ }
+ if(sendto(socket, &buffer, len, MSG_DONTWAIT,(struct sockaddr*)dest_addr.gen,addrlen)<0){
+ if(errno!=EINTR){
+ dbgprintf(0,"Error: sendto failed\n");
+ }
+ }
+ return;
+}
+
+void sendReset(int seq, u_int16_t ack_h, u_int32_t ack_l, int socket){
+ unsigned char buffer[1500];
+ struct dccp_hdr *dhdr;
+ struct dccp_hdr_ext *dhdre;
+ struct dccp_hdr_reset *dh_re;
+ struct iphdr* ip4hdr;
+ struct ip6_hdr* ip6hdr;
+ int len;
+ int addrlen;
+
+ int ip_hdr_len;
+ int dccp_hdr_len=sizeof(struct dccp_hdr)+sizeof(struct dccp_hdr_ext)+sizeof(struct dccp_hdr_reset);
+
+ memset(buffer, 0, 1500);
+
+ /*IP header*/
+ ip4hdr=NULL;
+ if(ip_type==AF_INET){
+ ip_hdr_len=sizeof(struct iphdr);
+ ip4hdr=(struct iphdr*)buffer;
+ ip4hdr->check=htons(0);
+ memcpy(&ip4hdr->daddr, &dest_addr.ipv4->sin_addr, sizeof(dest_addr.ipv4->sin_addr));
+ ip4hdr->frag_off=htons(0);
+ ip4hdr->id=htons(1);//first
+ ip4hdr->ihl=5;
+ ip4hdr->protocol=IPPROTO_DCCP;
+ memcpy(&ip4hdr->saddr, &src_addr.ipv4->sin_addr, sizeof(src_addr.ipv4->sin_addr));
+ ip4hdr->tos=0;
+ ip4hdr->tot_len=htons(ip_hdr_len+dccp_hdr_len);
+ ip4hdr->ttl=ttl;
+ ip4hdr->version=4;
+ }else{
+ ip_hdr_len=sizeof(struct ip6_hdr);
+ ip6hdr=(struct ip6_hdr*)buffer;
+ memcpy(&ip6hdr->ip6_dst, &dest_addr.ipv6->sin6_addr, sizeof(dest_addr.ipv6->sin6_addr));
+ memcpy(&ip6hdr->ip6_src, &src_addr.ipv6->sin6_addr, sizeof(src_addr.ipv6->sin6_addr));
+ ip6hdr->ip6_ctlun.ip6_un1.ip6_un1_flow=htonl(6<<28); //version, traffic class, flow label
+ ip6hdr->ip6_ctlun.ip6_un1.ip6_un1_hlim=ttl;
+ ip6hdr->ip6_ctlun.ip6_un1.ip6_un1_nxt=IPPROTO_DCCP;
+ ip6hdr->ip6_ctlun.ip6_un1.ip6_un1_plen=htons(dccp_hdr_len);
+ }
+
+ /*DCCP header*/
+ dhdr=(struct dccp_hdr*)(buffer+ip_hdr_len);
+ dhdre=(struct dccp_hdr_ext*)(buffer+ip_hdr_len+sizeof(struct dccp_hdr));
+ dh_re=(struct dccp_hdr_reset*)(buffer+ip_hdr_len+sizeof(struct dccp_hdr)+sizeof(struct dccp_hdr_ext));
+ dhdr->dccph_ccval=0;
+ dhdr->dccph_checksum=0;
+ dhdr->dccph_cscov=0;
+ dhdr->dccph_doff=dccp_hdr_len/4;
+ dhdr->dccph_dport=htons(dest_port);
+ dhdr->dccph_reserved=0;
+ dhdr->dccph_sport=htons(dest_port);
+ dhdr->dccph_x=1;
+ dhdr->dccph_type=DCCP_PKT_RESET;
+ dhdr->dccph_seq2=htonl(0); //Reserved if using 48 bit sequence numbers
+ dhdr->dccph_seq=htonl(0); //High 16bits of sequence number. Always make 0 for simplicity.
+ dhdre->dccph_seq_low=htonl(seq+1);
+ dh_re->dccph_reset_ack.dccph_ack_nr_high=ack_h;
+ dh_re->dccph_reset_ack.dccph_ack_nr_low=ack_l;
+ dh_re->dccph_reset_code=DCCP_RESET_CODE_CLOSED;
+ dh_re->dccph_reset_data[0]=0;
+ dh_re->dccph_reset_data[1]=0;
+ dh_re->dccph_reset_data[2]=0;
+
+ /*Checksums*/
+ if(ip_type==AF_INET){
+ dhdr->dccph_checksum=ipv4_pseudohdr_chksum((buffer+ip_hdr_len), dccp_hdr_len,
+ (unsigned char*) &dest_addr.ipv4->sin_addr,
+ (unsigned char*)&src_addr.ipv4->sin_addr, IPPROTO_DCCP);
+ ip4hdr->check=ipv4_chksum(buffer,ip_hdr_len);
+ }else{
+ dhdr->dccph_checksum=ipv6_pseudohdr_chksum((buffer+ip_hdr_len), dccp_hdr_len,
+ (unsigned char*) &dest_addr.ipv6->sin6_addr,
+ (unsigned char*)&src_addr.ipv6->sin6_addr, IPPROTO_DCCP);
+ }
+ len=ip_hdr_len+dccp_hdr_len;
+
+ /*Send*/
+ if(ip_type==AF_INET){
+ addrlen=sizeof(struct sockaddr_in);
+ }else{
+ addrlen=sizeof(struct sockaddr_in6);
+ }
+ if(sendto(socket, &buffer, len, MSG_DONTWAIT,(struct sockaddr*)dest_addr.gen,addrlen)<0){
+ if(errno!=EINTR){
+ dbgprintf(0,"Error: sendto failed\n");
+ }
+ }
+ return;
+}
+