status_t
ipv6_send_routed_data(net_protocol* _protocol, struct net_route* route,
net_buffer* buffer)
{
if (route == NULL)
return B_BAD_VALUE;
ipv6_protocol* protocol = (ipv6_protocol*)_protocol;
net_interface* interface = route->interface_address->interface;
uint8 protocolNumber;
if (protocol != NULL && protocol->socket != NULL)
protocolNumber = protocol->socket->protocol;
else
protocolNumber = buffer->protocol;
TRACE_SK(protocol, "SendRoutedData(%p, %p [%ld bytes])", route, buffer,
buffer->size);
sockaddr_in6& source = *(sockaddr_in6*)buffer->source;
sockaddr_in6& destination = *(sockaddr_in6*)buffer->destination;
buffer->flags &= ~(MSG_BCAST | MSG_MCAST);
if (IN6_IS_ADDR_UNSPECIFIED(&destination.sin6_addr))
return EDESTADDRREQ;
if (IN6_IS_ADDR_MULTICAST(&destination.sin6_addr))
buffer->flags |= MSG_MCAST;
uint16 dataLength = buffer->size;
// Add IPv6 header
NetBufferPrepend<ip6_hdr> header(buffer);
if (header.Status() != B_OK)
return header.Status();
if (buffer->size > 0xffff)
return EMSGSIZE;
uint32 flowinfo = 0;
// TODO: fill in the flow id from somewhere
if (protocol) {
// fill in traffic class
flowinfo |= htonl(protocol->service_type << 20);
}
// set lower 28 bits
header->ip6_flow = htonl(flowinfo) & IPV6_FLOWINFO_MASK;
// set upper 4 bits
header->ip6_vfc |= IPV6_VERSION;
header->ip6_plen = htons(dataLength);
header->ip6_nxt = protocolNumber;
header->ip6_hlim = ip6_select_hoplimit(protocol, buffer);
memcpy(&header->ip6_src, &source.sin6_addr, sizeof(in6_addr));
memcpy(&header->ip6_dst, &destination.sin6_addr, sizeof(in6_addr));
header.Sync();
// write the checksum for ICMPv6 sockets
if (protocolNumber == IPPROTO_ICMPV6
&& dataLength >= sizeof(struct icmp6_hdr)) {
NetBufferField<uint16, sizeof(ip6_hdr)
+ offsetof(icmp6_hdr, icmp6_cksum)>
icmpChecksum(buffer);
// first make sure the existing checksum is zero
*icmpChecksum = 0;
icmpChecksum.Sync();
uint16 checksum = gBufferModule->checksum(buffer, sizeof(ip6_hdr),
buffer->size - sizeof(ip6_hdr), false);
checksum = ipv6_checksum(&header->ip6_src,
&header->ip6_dst, dataLength, protocolNumber,
checksum);
*icmpChecksum = checksum;
}
char addrbuf[INET6_ADDRSTRLEN];
ip6_sprintf(&destination.sin6_addr, addrbuf);
TRACE_SK(protocol, " SendRoutedData(): destination: %s", addrbuf);
uint32 mtu = route->mtu ? route->mtu : interface->mtu;
if (buffer->size > mtu) {
// we need to fragment the packet
return send_fragments(protocol, route, buffer, mtu);
}
return sDatalinkModule->send_routed_data(route, buffer);
}
u_char *modify_packet(u_char *pkt_ptr,int pkt_type, int len,uint8_t* ether_src, uint8_t* ether_dst)
{
//printf("inside modify packet\n");
u_char *timeExceedePacket =(char *)malloc(sizeof(char)*(70));
memset(timeExceedePacket,0,70);
customIcmp *myicmp= (struct customIcmp *)malloc(sizeof(struct customIcmp));
memset(myicmp,0,36);
struct ether_header *eth_hdr = (struct ether_header *)pkt_ptr; //Pointer to ethernet
struct ip *ip_hdr = (struct ip *)(pkt_ptr + ETHERNET_HEADER_LEN); //point to an IP header structure
int i = 0;
for(i=0;i<6;i++){
eth_hdr->ether_shost[i] = ether_src[i];
eth_hdr->ether_dhost[i] = ether_dst[i];
}
if(pkt_type==1){
//change the src ip and dst ipaddr
struct in_addr inp;
inp=ip_hdr->ip_src;
ip_hdr->ip_src=ip_hdr->ip_dst;
ip_hdr->ip_dst=inp;
printf("Changing icmp Header\n");
struct icmphdr *icmp_hdr = (struct icmphdr *)(pkt_ptr+14+20);
icmp_hdr->type=0;
icmp_hdr->code=0;
icmp_hdr->checksum=0;
unsigned short csumicmp= htons(icmpChecksum((unsigned short *)icmp_hdr,len));
icmp_hdr->checksum=htons(csumicmp);
}
if(pkt_type==2){
//change the src ip and dst ipaddr
memcpy(timeExceedePacket,(char*)eth_hdr,14);
memcpy(myicmp->data,ip_hdr,28);
struct in_addr inp;
inp=ip_hdr->ip_src;
ARP_table *tmp_arp_table = arp_head;
while(tmp_arp_table){
if((tmp_arp_table->interface_mac_addr[0] == ether_src[0]) && (tmp_arp_table->interface_mac_addr[1] == ether_src[1]) && (tmp_arp_table->interface_mac_addr[2] == ether_src[2]) && (tmp_arp_table->interface_mac_addr[3] == ether_src[3]) && (tmp_arp_table->interface_mac_addr[4] == ether_src[4]) && (tmp_arp_table->interface_mac_addr[5] == ether_src[5]) ){
ip_hdr->ip_src = tmp_arp_table->interface_ip;
break;
}
}
ip_hdr->ip_dst=inp;
ip_hdr->ip_p=1;
ip_hdr->ip_len=htons(56);
printf("Changing icmp Header for type 2\n");
myicmp->type=11;
myicmp->code=0;
myicmp->checksum=0;
unsigned short csumicmp= htons(icmpChecksum((unsigned short *)myicmp,36));
myicmp->checksum=htons(csumicmp);
memcpy(timeExceedePacket+14+20,(char *)myicmp,36); //copy whole new icmp
}
if(pkt_type==3){
memcpy(timeExceedePacket,(char*)eth_hdr,14);
memcpy(myicmp->data,ip_hdr,28);
struct in_addr inp;
inp=ip_hdr->ip_src;
ARP_table *tmp_arp_table = arp_head;
while(tmp_arp_table){
if((tmp_arp_table->interface_mac_addr[0] == ether_src[0]) && (tmp_arp_table->interface_mac_addr[1] == ether_src[1]) && (tmp_arp_table->interface_mac_addr[2] == ether_src[2]) && (tmp_arp_table->interface_mac_addr[3] == ether_src[3]) && (tmp_arp_table->interface_mac_addr[4] == ether_src[4]) && (tmp_arp_table->interface_mac_addr[5] == ether_src[5]) ){
ip_hdr->ip_src = tmp_arp_table->interface_ip;
break;
}
}
ip_hdr->ip_dst=inp;
ip_hdr->ip_p=1;
ip_hdr->ip_len=htons(56);
printf("Changing icmp Header for type 3\n");
myicmp->type=3;
myicmp->code=1;
myicmp->checksum=0;
unsigned short csumicmp= htons(icmpChecksum((unsigned short *)myicmp,36));
myicmp->checksum=htons(csumicmp);
memcpy(timeExceedePacket+14+20,(char *)myicmp,36); //copy whole new icmp
}
if(pkt_type==4){
memcpy(timeExceedePacket,(char*)eth_hdr,14);
memcpy(myicmp->data,ip_hdr,28);
struct in_addr inp;
inp=ip_hdr->ip_src;
ip_hdr->ip_src = ip_hdr->ip_dst;
ip_hdr->ip_dst=inp;
ip_hdr->ip_p=1;
ip_hdr->ip_len=htons(56);
printf("Changing icmp Header for type 4\n");
myicmp->type=3;
myicmp->code=3;
myicmp->checksum=0;
unsigned short csumicmp= htons(icmpChecksum((unsigned short *)myicmp,36));
myicmp->checksum=htons(csumicmp);
memcpy(timeExceedePacket+14+20,(char *)myicmp,36); //copy whole new icmp
}
//Change the ttl and checksum
ip_hdr->ip_ttl-=1;
if(ip_hdr->ip_ttl==0){
ip_hdr->ip_ttl=64;
}
ip_hdr->ip_sum = (htons)(ip_checksum(ip_hdr));
if(pkt_type == 2 || pkt_type == 3 || pkt_type == 4){
memcpy(timeExceedePacket+14,ip_hdr,20);
return timeExceedePacket;
}
//printf("end of modify packet\n");
return pkt_ptr;
}
