void
capture_ipfc (const guchar *pd, int len, packet_counts *ld)
{
if (!BYTES_ARE_IN_FRAME(0, len, 16)) {
ld->other++;
return;
}
capture_llc(pd, 16, len, ld);
}
void
capture_sll(const guchar *pd, int len, packet_counts *ld)
{
guint16 protocol;
if (!BYTES_ARE_IN_FRAME(0, len, SLL_HEADER_SIZE)) {
ld->other++;
return;
}
protocol = pntohs(&pd[14]);
if (protocol <= 1536) { /* yes, 1536 - that's how Linux does it */
/*
* "proto" is *not* a length field, it's a Linux internal
* protocol type.
*/
switch (protocol) {
case LINUX_SLL_P_802_2:
/*
* 802.2 LLC.
*/
capture_llc(pd, len, SLL_HEADER_SIZE, ld);
break;
case LINUX_SLL_P_ETHERNET:
/*
* Ethernet.
*/
capture_eth(pd, SLL_HEADER_SIZE, len, ld);
break;
case LINUX_SLL_P_802_3:
/*
* Novell IPX inside 802.3 with no 802.2 LLC
* header.
*/
capture_ipx(ld);
break;
case LINUX_SLL_P_PPPHDLC:
/*
* PPP HDLC.
*/
capture_ppp_hdlc(pd, len, SLL_HEADER_SIZE, ld);
break;
default:
ld->other++;
break;
}
} else
capture_ethertype(protocol, pd, SLL_HEADER_SIZE, len, ld);
}
void
capture_fddi(const guchar *pd, int len, packet_counts *ld)
{
int offset = 0, fc;
if (!BYTES_ARE_IN_FRAME(0, len, FDDI_HEADER_SIZE + FDDI_PADDING)) {
ld->other++;
return;
}
offset = FDDI_PADDING + FDDI_HEADER_SIZE;
fc = (int) pd[FDDI_P_FC+FDDI_PADDING];
switch (fc) {
/* From now, only 802.2 SNAP (Async. LCC frame) is supported */
case FDDI_FC_LLC_ASYNC + 0 :
case FDDI_FC_LLC_ASYNC + 1 :
case FDDI_FC_LLC_ASYNC + 2 :
case FDDI_FC_LLC_ASYNC + 3 :
case FDDI_FC_LLC_ASYNC + 4 :
case FDDI_FC_LLC_ASYNC + 5 :
case FDDI_FC_LLC_ASYNC + 6 :
case FDDI_FC_LLC_ASYNC + 7 :
case FDDI_FC_LLC_ASYNC + 8 :
case FDDI_FC_LLC_ASYNC + 9 :
case FDDI_FC_LLC_ASYNC + 10 :
case FDDI_FC_LLC_ASYNC + 11 :
case FDDI_FC_LLC_ASYNC + 12 :
case FDDI_FC_LLC_ASYNC + 13 :
case FDDI_FC_LLC_ASYNC + 14 :
case FDDI_FC_LLC_ASYNC + 15 :
capture_llc(pd, offset, len, ld);
return;
default :
ld->other++;
return;
} /* fc */
} /* capture_fddi */
void
capture_ethertype(guint16 etype, const guchar *pd, int offset, int len,
packet_counts *ld)
{
switch (etype) {
case ETHERTYPE_ARP:
ld->arp++;
break;
case ETHERTYPE_IP:
capture_ip(pd, offset, len, ld);
break;
case ETHERTYPE_IPv6:
capture_ipv6(pd, offset, len, ld);
break;
case ETHERTYPE_IPX:
capture_ipx(ld);
break;
case ETHERTYPE_VLAN:
capture_vlan(pd, offset, len, ld);
break;
case ETHERTYPE_IEEE_802_1AD:
case ETHERTYPE_IEEE_802_1AH:
capture_ieee8021ah(pd, offset, len, ld);
break;
case ETHERTYPE_VINES_IP:
case ETHERTYPE_VINES_ECHO:
capture_vines(ld);
break;
case ETHERTYPE_BPQ:
capture_bpq(pd, offset, len, ld);
break;
case ETHERTYPE_JUMBO_LLC:
capture_llc(pd, offset, len, ld);
break;
default:
ld->other++;
break;
}
}
void
capture_eth(const guchar *pd, int offset, int len, packet_counts *ld)
{
guint16 etype, length;
int ethhdr_type; /* the type of ethernet frame */
if (!BYTES_ARE_IN_FRAME(offset, len, ETH_HEADER_SIZE)) {
ld->other++;
return;
}
etype = pntohs(&pd[offset+12]);
if (etype <= IEEE_802_3_MAX_LEN) {
/* Oh, yuck. Cisco ISL frames require special interpretation of the
destination address field; fortunately, they can be recognized by
checking the first 5 octets of the destination address, which are
01-00-0C-00-00 or 0C-00-0C-00-00 for ISL frames. */
if ((pd[offset] == 0x01 || pd[offset] == 0x0C) && pd[offset+1] == 0x00
&& pd[offset+2] == 0x0C && pd[offset+3] == 0x00
&& pd[offset+4] == 0x00) {
capture_isl(pd, offset, len, ld);
return;
}
}
/*
* If the type/length field is <= the maximum 802.3 length,
* and is not zero, this is an 802.3 frame, and it's a length
* field; it might be an Novell "raw 802.3" frame, with no
* 802.2 LLC header, or it might be a frame with an 802.2 LLC
* header.
*
* If the type/length field is >= the minimum Ethernet II length,
* this is an Ethernet II frame, and it's a type field.
*
* If the type/length field is > maximum 802.3 length and < minimum
* Ethernet II length, then this is an invalid packet.
*
* If the type/length field is zero (ETHERTYPE_UNK), this is
* a frame used internally by the Cisco MDS switch to contain
* Fibre Channel ("Vegas"). We treat that as an Ethernet II
* frame; the dissector for those frames registers itself with
* an ethernet type of ETHERTYPE_UNK.
*/
if (etype > IEEE_802_3_MAX_LEN && etype < ETHERNET_II_MIN_LEN) {
ld->other++;
return;
}
if (etype <= IEEE_802_3_MAX_LEN && etype != ETHERTYPE_UNK) {
length = etype;
/* Is there an 802.2 layer? I can tell by looking at the first 2
bytes after the 802.3 header. If they are 0xffff, then what
follows the 802.3 header is an IPX payload, meaning no 802.2.
(IPX/SPX is they only thing that can be contained inside a
straight 802.3 packet). A non-0xffff value means that there's an
802.2 layer inside the 802.3 layer */
if (pd[offset+14] == 0xff && pd[offset+15] == 0xff) {
ethhdr_type = ETHERNET_802_3;
}
else {
ethhdr_type = ETHERNET_802_2;
}
/* Convert the LLC length from the 802.3 header to a total
frame length, by adding in the size of any data that preceded
the Ethernet header, and adding in the Ethernet header size,
and set the payload and captured-payload lengths to the minima
of the total length and the frame lengths. */
length += offset + ETH_HEADER_SIZE;
if (len > length)
len = length;
} else {
ethhdr_type = ETHERNET_II;
}
offset += ETH_HEADER_SIZE;
switch (ethhdr_type) {
case ETHERNET_802_3:
capture_ipx(ld);
break;
case ETHERNET_802_2:
capture_llc(pd, offset, len, ld);
break;
case ETHERNET_II:
capture_ethertype(etype, pd, offset, len, ld);
break;
}
}
void
capture_tr(const guchar *pd, int offset, int len, packet_counts *ld) {
int source_routed = 0;
int frame_type;
int x;
guint8 trn_rif_bytes;
guint8 actual_rif_bytes;
guint16 first2_sr;
/* The trn_hdr struct, as separate variables */
guint8 trn_fc; /* field control field */
const guint8 *trn_shost; /* source host */
if (!BYTES_ARE_IN_FRAME(offset, len, TR_MIN_HEADER_LEN)) {
ld->other++;
return;
}
if ((x = check_for_old_linux(pd)))
{
/* Actually packet starts x bytes into what we have got but with all
source routing compressed
*/
/* pd = &pd[x]; */ offset+=x;
}
/* get the data */
trn_fc = pd[offset + 1];
trn_shost = &pd[offset + 8];
frame_type = (trn_fc & 192) >> 6;
/* if the high bit on the first byte of src hwaddr is 1, then
this packet is source-routed */
source_routed = trn_shost[0] & 128;
trn_rif_bytes = pd[offset + 14] & 31;
if (fix_linux_botches) {
/* the Linux 2.0 TR code strips source-route bits in
* order to test for SR. This can be removed from most
* packets with oltr, but not all. So, I try to figure out
* which packets should have been SR here. I'll check to
* see if there's a SNAP or IPX field right after
* my RIF fields.
*
* The Linux 2.4.18 code, at least appears to do the
* same thing, from a capture I got from somebody running
* 2.4.18 (RH 7.1, so perhaps this is a Red Hat
* "improvement").
*/
if (!source_routed && trn_rif_bytes > 0) {
if (pd[offset + 0x0e] != pd[offset + 0x0f]) {
first2_sr = pntohs(&pd[offset + 0xe0 + trn_rif_bytes]);
if (
(first2_sr == 0xaaaa &&
pd[offset + 0x10 + trn_rif_bytes] == 0x03) ||
first2_sr == 0xe0e0 ||
first2_sr == 0xe0aa ) {
source_routed = 1;
}
}
}
}
if (source_routed) {
actual_rif_bytes = trn_rif_bytes;
}
else {
trn_rif_bytes = 0;
actual_rif_bytes = 0;
}
if (fix_linux_botches) {
/* this is a silly hack for Linux 2.0.x. Read the comment
* below about LLC headers. If we're sniffing our own NIC,
* we get a full RIF, sometimes with garbage
*/
if ((source_routed && trn_rif_bytes == 2 && frame_type == 1) ||
(!source_routed && frame_type == 1)) {
/* look for SNAP or IPX only */
if ( (pd[offset + 0x20] == 0xaa && pd[offset + 0x21] == 0xaa && pd[offset + 0x22] == 03) ||
(pd[offset + 0x20] == 0xe0 && pd[offset + 0x21] == 0xe0) ) {
actual_rif_bytes = 18;
} else if (
pd[offset + 0x23] == 0 &&
pd[offset + 0x24] == 0 &&
pd[offset + 0x25] == 0 &&
pd[offset + 0x26] == 0x00 &&
pd[offset + 0x27] == 0x11) {
actual_rif_bytes = 18;
/* Linux 2.0.x also requires drivers pass up
* a fake SNAP and LLC header before the
* real LLC hdr for all Token Ring frames
* that arrive with DSAP and SSAP != 0xAA
* (i.e. for non SNAP frames e.g. for Netware
* frames) the fake SNAP header has the
* ETH_P_TR_802_2 ether type (0x0011) and the protocol id
* bytes as zero frame looks like :-
* TR Header | Fake LLC | Fake SNAP | Wire LLC | Rest of data
*/
offset += 8; /* Skip fake LLC and SNAP */
}
}
}
offset += actual_rif_bytes + TR_MIN_HEADER_LEN;
/* The package is either MAC or LLC */
switch (frame_type) {
/* MAC */
case 0:
ld->other++;
break;
case 1:
capture_llc(pd, offset, len, ld);
break;
default:
/* non-MAC, non-LLC, i.e., "Reserved" */
ld->other++;
break;
}
}
