int DecodeMPLS(ThreadVars *tv, DecodeThreadVars *dtv, Packet *p, uint8_t *pkt,
uint32_t len, PacketQueue *pq)
{
uint32_t shim;
int label;
int event = 0;
StatsIncr(tv, dtv->counter_mpls);
do {
if (len < MPLS_HEADER_LEN) {
ENGINE_SET_INVALID_EVENT(p, MPLS_HEADER_TOO_SMALL);
return TM_ECODE_FAILED;
}
memcpy(&shim, pkt, sizeof(shim));
pkt += MPLS_HEADER_LEN;
len -= MPLS_HEADER_LEN;
} while (MPLS_BOTTOM(shim) == 0);
label = MPLS_LABEL(shim);
if (label == MPLS_LABEL_IPV4) {
if (len > USHRT_MAX) {
return TM_ECODE_FAILED;
}
return DecodeIPV4(tv, dtv, p, pkt, len, pq);
}
else if (label == MPLS_LABEL_ROUTER_ALERT) {
/* Not valid at the bottom of the stack. */
event = MPLS_BAD_LABEL_ROUTER_ALERT;
}
else if (label == MPLS_LABEL_IPV6) {
if (len > USHRT_MAX) {
return TM_ECODE_FAILED;
}
return DecodeIPV6(tv, dtv, p, pkt, len, pq);
}
else if (label == MPLS_LABEL_NULL) {
/* Shouldn't appear on the wire. */
event = MPLS_BAD_LABEL_IMPLICIT_NULL;
}
else if (label < MPLS_MAX_RESERVED_LABEL) {
event = MPLS_BAD_LABEL_RESERVED;
}
if (event) {
goto end;
}
// Make sure we still have enough data. While we only need 1 byte to test
// for IPv4 and IPv4, we need for to check for ethernet.
if (len < MPLS_PW_LEN) {
ENGINE_SET_INVALID_EVENT(p, MPLS_PKT_TOO_SMALL);
return TM_ECODE_FAILED;
}
/* Best guess at inner packet. */
switch (pkt[0] >> 4) {
case MPLS_PROTO_IPV4:
if (len > USHRT_MAX) {
return TM_ECODE_FAILED;
}
DecodeIPV4(tv, dtv, p, pkt, len, pq);
break;
case MPLS_PROTO_IPV6:
if (len > USHRT_MAX) {
return TM_ECODE_FAILED;
}
DecodeIPV6(tv, dtv, p, pkt, len, pq);
break;
case MPLS_PROTO_ETHERNET_PW:
DecodeEthernet(tv, dtv, p, pkt + MPLS_PW_LEN, len - MPLS_PW_LEN,
pq);
break;
default:
ENGINE_SET_INVALID_EVENT(p, MPLS_UNKNOWN_PAYLOAD_TYPE);
return TM_ECODE_OK;
}
end:
if (event) {
ENGINE_SET_EVENT(p, event);
}
return TM_ECODE_OK;
}
int DecodeMPLS(ThreadVars *tv, DecodeThreadVars *dtv, Packet *p, uint8_t *pkt,
uint16_t len, PacketQueue *pq)
{
uint32_t shim;
int label;
int event = 0;
StatsIncr(tv, dtv->counter_mpls);
do {
if (len < MPLS_HEADER_LEN) {
ENGINE_SET_INVALID_EVENT(p, MPLS_HEADER_TOO_SMALL);
return TM_ECODE_FAILED;
}
shim = *(uint32_t *)pkt;
pkt += MPLS_HEADER_LEN;
len -= MPLS_HEADER_LEN;
} while (MPLS_BOTTOM(shim) == 0);
label = MPLS_LABEL(shim);
if (label == MPLS_LABEL_IPV4) {
return DecodeIPV4(tv, dtv, p, pkt, len, pq);
}
else if (label == MPLS_LABEL_ROUTER_ALERT) {
/* Not valid at the bottom of the stack. */
event = MPLS_BAD_LABEL_ROUTER_ALERT;
}
else if (label == MPLS_LABEL_IPV6) {
return DecodeIPV6(tv, dtv, p, pkt, len, pq);
}
else if (label == MPLS_LABEL_NULL) {
/* Shouldn't appear on the wire. */
event = MPLS_BAD_LABEL_IMPLICIT_NULL;
}
else if (label < MPLS_MAX_RESERVED_LABEL) {
event = MPLS_BAD_LABEL_RESERVED;
}
if (event) {
goto end;
}
/* Best guess at inner packet. */
switch (pkt[0] >> 4) {
case MPLS_PROTO_IPV4:
DecodeIPV4(tv, dtv, p, pkt, len, pq);
break;
case MPLS_PROTO_IPV6:
DecodeIPV6(tv, dtv, p, pkt, len, pq);
break;
case MPLS_PROTO_ETHERNET_PW:
DecodeEthernet(tv, dtv, p, pkt + MPLS_PW_LEN, len - MPLS_PW_LEN,
pq);
break;
default:
ENGINE_SET_INVALID_EVENT(p, MPLS_UNKNOWN_PAYLOAD_TYPE);
return TM_ECODE_OK;
}
end:
if (event) {
ENGINE_SET_EVENT(p, event);
}
return TM_ECODE_OK;
}
