/******************************************************************************
Author: Samuel Jero
-Date: 5/2011
+Date: 7/2011
Description: Encapsulation Functions for DCCP conversion to TCP
#include "pcap/sll.h"
/*Encapsulation start point and link layer selector*/
-int do_encap(int link, struct pcap_pkthdr *h, u_char **nptr, int *nlength, const u_char **optr, int *length)
+int do_encap(int link, struct packet *new, const struct const_packet *old)
{
switch(link){
case DLT_EN10MB:
/*Ethernet*/
- if(!ethernet_encap(h, nptr, nlength, optr, length)){
+ if(!ethernet_encap(new, old)){
return 0;
}
break;
case DLT_RAW:
/*Raw. Just IP*/
- if(!ipv4_encap(h, nptr, nlength, optr, length)){
+ if(!ipv4_encap(new, old)){
return 0;
}
break;
case DLT_LINUX_SLL:
/*Linux Cooked Capture*/
- if(!linux_cooked_encap(h, nptr, nlength, optr, length)){
+ if(!linux_cooked_encap(new, old)){
return 0;
}
break;
}
/*Adjust libpcap header*/
- if(h->caplen >= h->len || h->caplen >= *nlength){
- h->caplen=*nlength;
+ if(new->h->caplen >= new->h->len || new->h->caplen >= new->length){
+ new->h->caplen=new->length;
}
- h->len=*nlength;
+ new->h->len=new->length;
return 1;
}
/*Standard Ethernet Encapsulation*/
-int ethernet_encap(struct pcap_pkthdr *h, u_char **nptr, int *nlength, const u_char **optr, int *length)
+int ethernet_encap(struct packet *new, const struct const_packet *old)
{
- struct ether_header *ethh;
- int next_len;
- int next_nlen;
- u_char *next_nptr;
- const u_char *next_optr;
+ struct ether_header *ethh;
+ struct const_packet nold;
+ struct packet nnew;
/*Safety checks*/
- if(!h || !nptr || !nlength || !optr || !length || !*nptr || !*optr){
+ if(!new || !old || !new->data || !old->data || !new->h || !old->h){
dbgprintf(0,"Error: Ethernet Encapsulation Function given bad data!\n");
return 0;
}
- if(*length < sizeof(struct ether_header) || *nlength < sizeof(struct ether_header)){
+ if(old->length < sizeof(struct ether_header) || new->length < sizeof(struct ether_header)){
dbgprintf(0, "Error: Ethernet Encapsulation Function given packet of wrong size!\n");
return 0;
}
/*Copy Ethernet header over*/
- memcpy(*nptr, *optr, sizeof(struct ether_header));
+ memcpy(new->data, old->data, sizeof(struct ether_header));
/*Cast Pointer*/
- ethh=(struct ether_header*)(*nptr);
+ ethh=(struct ether_header*)(new->data);
/*Adjust pointers and lengths*/
- next_optr= *optr+ sizeof(struct ether_header);
- next_nptr= *nptr+ sizeof(struct ether_header);
- next_len= *length- sizeof(struct ether_header);
- next_nlen= *nlength- sizeof(struct ether_header);
+ nold.data= old->data+ sizeof(struct ether_header);
+ nnew.data= new->data + sizeof(struct ether_header);
+ nold.length= old->length - sizeof(struct ether_header);
+ nnew.length= new->length - sizeof(struct ether_header);
/*Select Next Protocol*/
switch(ntohs(ethh->ether_type)){
case ETHERTYPE_IP:
- if(!ipv4_encap(h, &next_nptr, &next_nlen, &next_optr, &next_len)){
+ if(!ipv4_encap(&nnew, &nold)){
return 0;
}
break;
}
/*Adjust length*/
- *nlength=next_nlen + sizeof(struct ether_header);
+ new->length=nnew.length + sizeof(struct ether_header);
return 1;
}
/*IPv4 Encapsulation*/
-int ipv4_encap(struct pcap_pkthdr *h, u_char **nptr, int *nlength, const u_char **optr, int *length)
+int ipv4_encap(struct packet *new, const struct const_packet *old)
{
- struct iphdr *iph;
- int next_len;
- int next_nlen;
- u_char *next_nptr;
- const u_char *next_optr;
+ struct iphdr *iph;
+ struct packet nnew;
+ struct const_packet nold;
/*Safety checks*/
- if(!h || !nptr || !nlength || !optr || !length || !*nptr || !*optr){
+ if(!new || !old || !new->data || !old->data || !new->h || !old->h){
dbgprintf(0,"Error: IPv4 Encapsulation Function given bad data!\n");
return 0;
}
- if(*length < sizeof(struct iphdr) || *nlength < sizeof(struct iphdr)){
+ if(old->length < sizeof(struct iphdr) || new->length < sizeof(struct iphdr)){
dbgprintf(0, "Error: IPv4 Encapsulation Function given packet of wrong size!\n");
return 0;
}
/*Copy IPv4 header over*/
- memcpy(*nptr, *optr, sizeof(struct iphdr));
+ memcpy(new->data, old->data, sizeof(struct iphdr));
/*Cast Pointer*/
- iph=(struct iphdr*)(*nptr);
+ iph=(struct iphdr*)(new->data);
/*Adjust pointers and lengths*/
- next_optr= *optr +iph->ihl*4;
- next_nptr= *nptr +iph->ihl*4;
- next_len= *length -iph->ihl*4;
- next_nlen= *nlength-iph->ihl*4;
+ nold.data= old->data +iph->ihl*4;
+ nnew.data= new->data +iph->ihl*4;
+ nold.length= old->length -iph->ihl*4;
+ nnew.length= new->length -iph->ihl*4;
/*Confirm that this is IPv4*/
if(iph->version!=4){
switch(iph->protocol){
case 0x21:
/*DCCP*/
- if(!convert_packet(h, &next_nptr, &next_nlen, &next_optr, &next_len)){
+ nnew.src_id=iph->saddr;
+ nnew.dest_id=iph->daddr;
+ if(!convert_packet(&nnew, &nold)){
return 0;
}
break;
iph->check=htonl(0);
/*Adjust length*/
- *nlength=next_nlen + iph->ihl*4;
+ new->length=nnew.length + iph->ihl*4;
/*Determine if computed length is reasonable*/
- if(*nlength > 0xFFFF){
+ if(nnew.length > 0xFFFF){
dbgprintf(1, "Error: Given TCP header+data length is too large for an IPv4 packet!\n");
return 0;
}
/*Adjust IPv4 header to account for packet's total length*/
- iph->tot_len=htons(*nlength);
+ iph->tot_len=htons(nnew.length);
return 1;
}
-int linux_cooked_encap(struct pcap_pkthdr *h, u_char **nptr, int *nlength, const u_char **optr, int *length)
+int linux_cooked_encap(struct packet *new, const struct const_packet *old)
{
- struct sll_header *slh;
- int next_len;
- int next_nlen;
- u_char *next_nptr;
- const u_char *next_optr;
+ struct sll_header *slh;
+ struct packet nnew;
+ struct const_packet nold;
/*Safety checks*/
- if(!h || !nptr || !nlength || !optr || !length || !*nptr || !*optr){
+ if(!new|| !old || !new->data || !old->data || !new->h || !old->h){
dbgprintf(0,"Error: SLL Encapsulation Function given bad data!\n");
return 0;
}
- if(*length < sizeof(struct sll_header) || *nlength < sizeof(struct sll_header)){
+ if(old->length < sizeof(struct sll_header) || new->length < sizeof(struct sll_header)){
dbgprintf(0, "Error: SLL Encapsulation Function given packet of wrong size!\n");
return 0;
}
/*Copy SLL header over*/
- memcpy(*nptr, *optr, sizeof(struct sll_header));
+ memcpy(new->data, old->data, sizeof(struct sll_header));
/*Cast Pointer*/
- slh=(struct sll_header*)(*nptr);
+ slh=(struct sll_header*)(new->data);
/*Adjust pointers and lengths*/
- next_optr= *optr + sizeof(struct sll_header);
- next_nptr= *nptr + sizeof(struct sll_header);
- next_len= *length - sizeof(struct sll_header);
- next_nlen= *nlength- sizeof(struct sll_header);
+ nold.data= old->data + sizeof(struct sll_header);
+ nnew.data= new->data + sizeof(struct sll_header);
+ nold.length= old->length - sizeof(struct sll_header);
+ nnew.length= new->length- sizeof(struct sll_header);
/*Confirm that this is SLL*/
if(ntohs(slh->sll_pkttype) > 4){
/*Select Next Protocol*/
switch(ntohs(slh->sll_protocol)){
case ETHERTYPE_IP:
- if(!ipv4_encap(h, &next_nptr, &next_nlen, &next_optr, &next_len)){
+ if(!ipv4_encap(&nnew, &nold)){
return 0;
}
break;
}
/*Adjust length*/
- *nlength=next_nlen + sizeof(struct sll_header);
+ new->length=nnew.length + sizeof(struct sll_header);
return 1;
}
projects / dccp2tcp / blobdiff