int
snap_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen,
const struct lladdr_info *src, const struct lladdr_info *dst,
u_int bridge_pad)
{
uint32_t orgcode;
u_short et;
int ret;
ND_TCHECK_5(p);
if (caplen < 5 || length < 5)
goto trunc;
orgcode = EXTRACT_BE_U_3(p);
et = EXTRACT_BE_U_2(p + 3);
if (ndo->ndo_eflag) {
/*
* Somebody's already printed the MAC addresses, if there
* are any, so just print the SNAP header, not the MAC
* addresses.
*/
ND_PRINT("oui %s (0x%06x), %s %s (0x%04x), length %u: ",
tok2str(oui_values, "Unknown", orgcode),
orgcode,
(orgcode == 0x000000 ? "ethertype" : "pid"),
tok2str(oui_to_struct_tok(orgcode), "Unknown", et),
et, length - 5);
}
p += 5;
length -= 5;
caplen -= 5;
switch (orgcode) {
case OUI_ENCAP_ETHER:
case OUI_CISCO_90:
/*
* This is an encapsulated Ethernet packet,
* or a packet bridged by some piece of
* Cisco hardware; the protocol ID is
* an Ethernet protocol type.
*/
ret = ethertype_print(ndo, et, p, length, caplen, src, dst);
if (ret)
return (ret);
break;
case OUI_APPLETALK:
if (et == ETHERTYPE_ATALK) {
/*
* No, I have no idea why Apple used one
* of their own OUIs, rather than
* 0x000000, and an Ethernet packet
* type, for Appletalk data packets,
* but used 0x000000 and an Ethernet
* packet type for AARP packets.
*/
ret = ethertype_print(ndo, et, p, length, caplen, src, dst);
if (ret)
return (ret);
}
break;
case OUI_CISCO:
switch (et) {
case PID_CISCO_CDP:
cdp_print(ndo, p, length, caplen);
return (1);
case PID_CISCO_DTP:
dtp_print(ndo, p, length);
return (1);
case PID_CISCO_UDLD:
udld_print(ndo, p, length);
return (1);
case PID_CISCO_VTP:
vtp_print(ndo, p, length);
return (1);
case PID_CISCO_PVST:
case PID_CISCO_VLANBRIDGE:
stp_print(ndo, p, length);
return (1);
default:
break;
}
break;
case OUI_RFC2684:
switch (et) {
case PID_RFC2684_ETH_FCS:
case PID_RFC2684_ETH_NOFCS:
/*
* XXX - remove the last two bytes for
* PID_RFC2684_ETH_FCS?
*/
/*
* Skip the padding.
*/
ND_TCHECK_LEN(p, bridge_pad);
caplen -= bridge_pad;
length -= bridge_pad;
p += bridge_pad;
/*
* What remains is an Ethernet packet.
*/
ether_print(ndo, p, length, caplen, NULL, NULL);
return (1);
case PID_RFC2684_802_5_FCS:
case PID_RFC2684_802_5_NOFCS:
/*
* XXX - remove the last two bytes for
* PID_RFC2684_ETH_FCS?
*/
/*
* Skip the padding, but not the Access
* Control field.
*/
ND_TCHECK_LEN(p, bridge_pad);
caplen -= bridge_pad;
length -= bridge_pad;
p += bridge_pad;
/*
* What remains is an 802.5 Token Ring
* packet.
*/
token_print(ndo, p, length, caplen);
return (1);
case PID_RFC2684_FDDI_FCS:
case PID_RFC2684_FDDI_NOFCS:
/*
* XXX - remove the last two bytes for
* PID_RFC2684_ETH_FCS?
*/
/*
* Skip the padding.
*/
ND_TCHECK_LEN(p, bridge_pad + 1);
caplen -= bridge_pad + 1;
length -= bridge_pad + 1;
p += bridge_pad + 1;
/*
* What remains is an FDDI packet.
*/
fddi_print(ndo, p, length, caplen);
return (1);
case PID_RFC2684_BPDU:
stp_print(ndo, p, length);
return (1);
}
}
if (!ndo->ndo_eflag) {
/*
* Nobody printed the link-layer addresses, so print them, if
* we have any.
*/
if (src != NULL && dst != NULL) {
ND_PRINT("%s > %s ",
(src->addr_string)(ndo, src->addr),
(dst->addr_string)(ndo, dst->addr));
}
/*
* Print the SNAP header, but if the OUI is 000000, don't
* bother printing it, and report the PID as being an
* ethertype.
*/
if (orgcode == 0x000000) {
ND_PRINT("SNAP, ethertype %s (0x%04x), length %u: ",
tok2str(ethertype_values, "Unknown", et),
et, length);
} else {
ND_PRINT("SNAP, oui %s (0x%06x), pid %s (0x%04x), length %u: ",
tok2str(oui_values, "Unknown", orgcode),
orgcode,
tok2str(oui_to_struct_tok(orgcode), "Unknown", et),
et, length);
}
}
return (0);
trunc:
ND_PRINT("[|snap]");
return (1);
}
int
snap_print(packetbody_t p, u_int length, u_int caplen, u_int bridge_pad)
{
u_int32_t orgcode;
register u_short et;
register int ret;
PACKET_HAS_SPACE_OR_TRUNC(p, 5);
orgcode = EXTRACT_24BITS(p);
et = EXTRACT_16BITS(p + 3);
if (eflag) {
const struct tok *tok = null_values;
const struct oui_tok *otp;
for (otp = &oui_to_tok[0]; otp->tok != NULL; otp++) {
if (otp->oui == orgcode) {
tok = otp->tok;
break;
}
}
(void)printf("oui %s (0x%06x), %s %s (0x%04x): ",
tok2str(oui_values, "Unknown", orgcode),
orgcode,
(orgcode == 0x000000 ? "ethertype" : "pid"),
tok2str(tok, "Unknown", et),
et);
}
p += 5;
length -= 5;
caplen -= 5;
switch (orgcode) {
case OUI_ENCAP_ETHER:
case OUI_CISCO_90:
/*
* This is an encapsulated Ethernet packet,
* or a packet bridged by some piece of
* Cisco hardware; the protocol ID is
* an Ethernet protocol type.
*/
ret = ethertype_print(gndo, et, p, length, caplen);
if (ret)
return (ret);
break;
case OUI_APPLETALK:
if (et == ETHERTYPE_ATALK) {
/*
* No, I have no idea why Apple used one
* of their own OUIs, rather than
* 0x000000, and an Ethernet packet
* type, for Appletalk data packets,
* but used 0x000000 and an Ethernet
* packet type for AARP packets.
*/
ret = ethertype_print(gndo, et, p, length, caplen);
if (ret)
return (ret);
}
break;
case OUI_CISCO:
switch (et) {
case PID_CISCO_CDP:
cdp_print(p, length, caplen);
return (1);
case PID_CISCO_DTP:
dtp_print(p, length);
return (1);
case PID_CISCO_UDLD:
udld_print(p, length);
return (1);
case PID_CISCO_VTP:
vtp_print(p, length);
return (1);
case PID_CISCO_PVST:
stp_print(p, length);
return (1);
default:
break;
}
case OUI_RFC2684:
switch (et) {
case PID_RFC2684_ETH_FCS:
case PID_RFC2684_ETH_NOFCS:
/*
* XXX - remove the last two bytes for
* PID_RFC2684_ETH_FCS?
*/
/*
* Skip the padding.
*/
PACKET_HAS_SPACE_OR_TRUNC(p, bridge_pad);
caplen -= bridge_pad;
length -= bridge_pad;
p += bridge_pad;
/*
* What remains is an Ethernet packet.
*/
ether_print(gndo, p, length, caplen, NULL, NULL);
return (1);
case PID_RFC2684_802_5_FCS:
case PID_RFC2684_802_5_NOFCS:
/*
* XXX - remove the last two bytes for
* PID_RFC2684_ETH_FCS?
*/
/*
* Skip the padding, but not the Access
* Control field.
*/
PACKET_HAS_SPACE_OR_TRUNC(p, bridge_pad);
caplen -= bridge_pad;
length -= bridge_pad;
p += bridge_pad;
/*
* What remains is an 802.5 Token Ring
* packet.
*/
token_print(p, length, caplen);
return (1);
case PID_RFC2684_FDDI_FCS:
case PID_RFC2684_FDDI_NOFCS:
/*
* XXX - remove the last two bytes for
* PID_RFC2684_ETH_FCS?
*/
/*
* Skip the padding.
*/
PACKET_HAS_SPACE_OR_TRUNC(p, bridge_pad + 1);
caplen -= bridge_pad + 1;
length -= bridge_pad + 1;
p += bridge_pad + 1;
/*
* What remains is an FDDI packet.
*/
fddi_print(p, length, caplen);
return (1);
case PID_RFC2684_BPDU:
stp_print(p, length);
return (1);
}
}
return (0);
trunc:
(void)printf("[|snap]");
return (1);
}
