IPv6 support!

[dccp2tcp] / encap.c

diff --git a/encap.c b/encap.c
index 736cf3a3d06c3684dc757fe309c6aa9a23baa602..1153e0638e9a6cf4f1498bd7c14521124e6f3263 100644 (file)
--- a/encap.c
+++ b/encap.c
@@ -1,14 +1,15 @@
 /******************************************************************************
 Author: Samuel Jero
 
-Date: 11/2011
+Date: 11/2012
 
 Description: Encapsulation Functions for DCCP conversion to TCP
 
 ******************************************************************************/
 #include "dccp2tcp.h"
 #include "encap.h"
-#include "pcap/sll.h"
+#include <pcap/sll.h>
+#include <netinet/ip6.h>
 
 /*Encapsulation start point and link layer selector*/
 int do_encap(int link, struct packet *new, const struct const_packet *old)
@@ -84,6 +85,11 @@ int ethernet_encap(struct packet *new, const struct const_packet *old)
                                                        return 0;
                                        }
                                        break;
+                       case ETHERTYPE_IPV6:
+                                       if(!ipv6_encap(&nnew, &nold)){
+                                                       return 0;
+                                       }
+                                       break;
                        default:
                                        dbgprintf(1, "Unknown Next Protocol at Ethernet\n");
                                        return 0;
@@ -95,6 +101,87 @@ int ethernet_encap(struct packet *new, const struct const_packet *old)
 return 1;
 }
 
+/*IPv6 Encapsulation*/
+int ipv6_encap(struct packet *new, const struct const_packet *old)
+{
+               struct ip6_hdr          *iph;
+               struct packet           nnew;
+               struct const_packet     nold;
+
+               /*Safety checks*/
+               if(!new || !old || !new->data || !old->data || !new->h || !old->h){
+                       dbgprintf(0,"Error: IPv6 Encapsulation Function given bad data!\n");
+                       return 0;
+               }
+               if(old->length < sizeof(struct ip6_hdr) || new->length < sizeof(struct ip6_hdr)){
+                       dbgprintf(0, "Error: IPv6 Encapsulation Function given packet of wrong size!\n");
+                       return 0;
+               }
+
+               /*Copy IPv6 header over*/
+               memcpy(new->data, old->data, sizeof(struct ip6_hdr));
+
+               /*Cast Pointer*/
+               iph=(struct ip6_hdr*)(new->data);
+
+               /*Adjust pointers and lengths*/
+               nold.data= old->data + sizeof(struct ip6_hdr);
+               nnew.data= new->data +sizeof(struct ip6_hdr);
+               nold.length= old->length - sizeof(struct ip6_hdr);
+               nnew.length= new->length - sizeof(struct ip6_hdr);
+               nnew.h=new->h;
+               nold.h=old->h;
+
+               /*Confirm that this is IPv6*/
+               if((ntohl(iph->ip6_ctlun.ip6_un1.ip6_un1_flow) & (0xF0000000)) == (60000000)){
+                       dbgprintf(1, "Note: Packet is not IPv6\n");
+                       return 0;
+               }
+
+               /*Select Next Protocol*/
+               switch(iph->ip6_ctlun.ip6_un1.ip6_un1_nxt){
+                       case 33:
+                                       /*DCCP*/
+                                       nnew.id_len=16;
+                                       nnew.src_id=malloc(nnew.id_len);
+                                       nnew.dest_id=malloc(nnew.id_len);
+                                       if(nnew.src_id==NULL||nnew.dest_id==NULL){
+                                               dbgprintf(0,"Error: Couldn't allocate Memory\n");
+                                               exit(1);
+                                       }
+                                       memcpy(nnew.src_id,&iph->ip6_src,nnew.id_len);
+                                       memcpy(nnew.dest_id,&iph->ip6_dst,nnew.id_len);
+                                       if(!convert_packet(&nnew, &nold)){
+                                               return 0;
+                                       }
+                                       break;
+                       default:
+                                       dbgprintf(1, "Unknown Next Protocol at IPv6\n");
+                                       return 0;
+                                       break;
+               }
+
+               /*set ip to indicate that TCP is next protocol*/
+               iph->ip6_ctlun.ip6_un1.ip6_un1_nxt=6;
+
+               /*Determine if computed length is reasonable*/
+               if(nnew.length > 0xFFFF){
+                               dbgprintf(1, "Error: Given TCP data length is too large for an IPv6 packet!\n");
+                               return 0;
+               }
+
+               /*Adjust IPv6 header to account for packet's total length*/
+               iph->ip6_ctlun.ip6_un1.ip6_un1_plen=htons(new->length);
+
+               /*Adjust length*/
+               new->length=nnew.length + sizeof(struct ip6_hdr);
+
+               /*Cleanup*/
+               free(nnew.dest_id);
+               free(nnew.src_id);
+return 1;
+}
+
 /*IPv4 Encapsulation*/
 int ipv4_encap(struct packet *new, const struct const_packet *old)
 {
@@ -134,10 +221,17 @@ int ipv4_encap(struct packet *new, const struct const_packet *old)
 
                /*Select Next Protocol*/
                switch(iph->protocol){
-                       case 0x21:
+                       case 33:
                                        /*DCCP*/
-                                       nnew.src_id=iph->saddr;
-                                       nnew.dest_id=iph->daddr;
+                                       nnew.id_len=4;
+                                       nnew.src_id=malloc(nnew.id_len);
+                                       nnew.dest_id=malloc(nnew.id_len);
+                                       if(nnew.src_id==NULL||nnew.dest_id==NULL){
+                                               dbgprintf(0,"Error: Couldn't allocate Memory\n");
+                                               exit(1);
+                                       }
+                                       memcpy(nnew.src_id,&iph->saddr,nnew.id_len);
+                                       memcpy(nnew.dest_id,&iph->daddr,nnew.id_len);
                                        if(!convert_packet(&nnew, &nold)){
                                                return 0;
                                        }
@@ -163,6 +257,10 @@ int ipv4_encap(struct packet *new, const struct const_packet *old)
 
                /*Adjust IPv4 header to account for packet's total length*/
                iph->tot_len=htons(new->length);
+
+               /*Cleanup*/
+               free(nnew.src_id);
+               free(nnew.dest_id);
 return 1;
 }
 
@@ -210,6 +308,11 @@ int linux_cooked_encap(struct packet *new, const struct const_packet *old)
                                                return 0;
                                }
                                break;
+               case ETHERTYPE_IPV6:
+                               if(!ipv6_encap(&nnew, &nold)){
+                                               return 0;
+                               }
+                               break;
                default:
                                dbgprintf(1, "Unknown Next Protocol at SLL\n");
                                return 0;