PtrPacket BaseSniffer::next_packet() {
sniff_data data;
const int iface_type = pcap_datalink(handle_);
pcap_handler handler = 0;
if (extract_raw_) {
handler = &sniff_loop_handler<RawPDU>;
}
else if (iface_type == DLT_EN10MB) {
handler = sniff_loop_eth_handler;
}
else if (iface_type == DLT_IEEE802_11_RADIO) {
#ifdef TINS_HAVE_DOT11
handler = &sniff_loop_handler<RadioTap>;
#else
throw protocol_disabled();
#endif
}
else if (iface_type == DLT_IEEE802_11) {
#ifdef TINS_HAVE_DOT11
handler = sniff_loop_dot11_handler;
#else
throw protocol_disabled();
#endif
}
#ifdef DLT_PKTAP
else if (iface_type == DLT_PKTAP) {
handler = &sniff_loop_handler<PKTAP>;
}
#endif // DLT_PKTAP
else if (iface_type == DLT_NULL) {
handler = &sniff_loop_handler<Tins::Loopback>;
}
else if (iface_type == DLT_LINUX_SLL) {
handler = &sniff_loop_handler<SLL>;
}
else if (iface_type == DLT_PPI) {
handler = &sniff_loop_handler<PPI>;
}
else {
throw unknown_link_type();
}
// keep calling pcap_loop until a well-formed packet is found.
while (data.pdu == 0 && data.packet_processed) {
data.packet_processed = false;
if (pcap_loop(handle_, 1, handler, (u_char*)&data) < 0) {
return PtrPacket(0, Timestamp());
}
}
return PtrPacket(data.pdu, data.tv);
}
PDU* pdu_from_dlt_flag(int flag,
const uint8_t* buffer,
uint32_t size,
bool rawpdu_on_no_match) {
switch (flag) {
case DLT_EN10MB:
return new EthernetII(buffer, size);
#ifdef TINS_HAVE_DOT11
case DLT_IEEE802_11_RADIO:
return new RadioTap(buffer, size);
case DLT_IEEE802_11:
return Dot11::from_bytes(buffer, size);
#else // TINS_HAVE_DOT11
case DLT_IEEE802_11_RADIO:
case DLT_IEEE802_11:
throw protocol_disabled();
#endif // TINS_HAVE_DOT11
case DLT_NULL:
return new Loopback(buffer, size);
case DLT_LINUX_SLL:
return new SLL(buffer, size);
case DLT_PPI:
return new PPI(buffer, size);
default:
return rawpdu_on_no_match ? new RawPDU(buffer, size) : 0;
};
}
PPI::PPI(const uint8_t *buffer, uint32_t total_sz) {
if(total_sz < sizeof(_header))
throw malformed_packet();
std::memcpy(&_header, buffer, sizeof(_header));
if(length() > total_sz || length() < sizeof(_header))
throw malformed_packet();
buffer += sizeof(_header);
total_sz -= sizeof(_header);
// There are some options
const size_t options_length = length() - sizeof(_header);
if(options_length > 0) {
_data.assign(buffer, buffer + options_length);
buffer += options_length;
total_sz -= static_cast<uint32_t>(options_length);
}
if(total_sz > 0) {
switch(dlt()) {
case DLT_IEEE802_11:
#ifdef HAVE_DOT11
parse_80211(buffer, total_sz);
#else
throw protocol_disabled();
#endif
break;
case DLT_EN10MB:
if(Internals::is_dot3(buffer, total_sz))
inner_pdu(new Dot3(buffer, total_sz));
else
inner_pdu(new EthernetII(buffer, total_sz));
break;
case DLT_IEEE802_11_RADIO:
#ifdef HAVE_DOT11
inner_pdu(new RadioTap(buffer, total_sz));
#else
throw protocol_disabled();
#endif
break;
case DLT_NULL:
inner_pdu(new Loopback(buffer, total_sz));
break;
case DLT_LINUX_SLL:
inner_pdu(new Tins::SLL(buffer, total_sz));
break;
}
}
}
