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/*
* netsniff-ng - the packet sniffing beast
* Copyright 2009, 2010 Daniel Borkmann.
* Copyright 2018 Markus Amend
* Subject to the GPL, version 2.
*/
#include <stdio.h>
#include <stdint.h>
#include <netinet/in.h> /* for ntohs() */
#include "proto.h"
#include "protos.h"
#include "pkt_buff.h"
struct dccphdr {
uint16_t source;
uint16_t dest;
uint8_t data_offs;
uint8_t cc_cscov;
uint16_t checks;
#if defined(__LITTLE_ENDIAN_BITFIELD)
__extension__ uint32_t x:1,
type:4,
res:3,
sqnr:24;
#elif defined (__BIG_ENDIAN_BITFIELD)
__extension__ uint32_t res:3,
type:4,
x:1,
sqnr:24;
#else
# error "Please fix <asm/byteorder.h>"
#endif
} __packed;
struct dccpexthdr {
uint32_t seqnr_low;
} __packed;
struct ack_subhdr {
uint32_t res:8,
acknr_low: 24;
} __packed;
struct ack_extsubhdr {
uint16_t res;
uint16_t acknr_high;
uint32_t acknr_low;
} __packed;
static char* dccp_pkt_type(uint8_t type) {
switch(type) {
case 0: return "Request";
case 1: return "Response";
case 2: return "Data";
case 3: return "Ack";
case 4: return "DataAck";
case 5: return "CloseReq";
case 6: return "Close";
case 7: return "Reset";
case 8: return "Sync";
case 9: return "SyncAck";
case 10 ... 15: return "Reserved";
}
return "Undef";
}
static void dccp(struct pkt_buff *pkt)
{
struct dccphdr *dccp = (struct dccphdr *) pkt_pull(pkt, sizeof(*dccp));
struct dccpexthdr *dccpext = NULL;
struct ack_subhdr *ack = NULL;
struct ack_extsubhdr *ackext = NULL;
uint16_t src, dest;
uint64_t seqnr;
int64_t acknr = -1;
size_t used_hdr = 0;
if (dccp == NULL)
return;
used_hdr += sizeof(*dccp);
seqnr = (uint64_t) ntohl(dccp->sqnr);
/* check for extended sequence number */
if (dccp->x) {
dccpext = (struct dccpexthdr *) pkt_pull(pkt, sizeof(*dccpext));
if (dccpext == NULL)
return;
used_hdr += sizeof(*dccpext);
seqnr = (((uint64_t) seqnr)<<24) | ntohl(dccpext->seqnr_low);
}
/* check for ack header */
if (dccp->type == 1 || (dccp->type >= 2 && dccp->type <= 9)) {
if (dccp->x) {
/* Extended ack header */
ackext = (struct ack_extsubhdr *) pkt_pull(pkt, sizeof(*ackext));
if (ackext == NULL)
return;
used_hdr += sizeof(*ackext);
acknr = (((uint64_t) ntohs(ackext->acknr_high))<<32) |
ntohl(ackext->acknr_low);
} else {
/* standard ack header */
ack = (struct ack_subhdr *) pkt_pull(pkt, sizeof(*ack));
if (ack == NULL)
return;
used_hdr += sizeof(*ack);
acknr = ntohl((uint32_t) ack->acknr_low);
}
}
src = ntohs(dccp->source);
dest = ntohs(dccp->dest);
tprintf(" [ DCCP ");
tprintf("Port (%u", src);
tprintf(" => %u", dest);
tprintf("), ");
tprintf("Header Len (%u Bytes), ", dccp->data_offs * 4);
tprintf("Type: %s, ", dccp_pkt_type((uint8_t) dccp->type));
tprintf("Seqnr:%lu", seqnr);
if (acknr > 0)
tprintf(", AckNr:%lu", acknr);
tprintf(" ]\n");
}
static void dccp_less(struct pkt_buff *pkt)
{
struct dccphdr *dccp = (struct dccphdr *) pkt_pull(pkt, sizeof(*dccp));
uint16_t src, dest;
if (dccp == NULL)
return;
src = ntohs(dccp->source);
dest = ntohs(dccp->dest);
tprintf(" DCCP %u", src);
tprintf("/%u", dest);
}
struct protocol dccp_ops = {
.key = 0x21,
.print_full = dccp,
.print_less = dccp_less,
};
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