diff options
Diffstat (limited to 'core.cpp')
| -rw-r--r-- | core.cpp | 364 |
1 files changed, 364 insertions, 0 deletions
diff --git a/core.cpp b/core.cpp new file mode 100644 index 0000000..11a20f7 --- /dev/null +++ b/core.cpp @@ -0,0 +1,364 @@ +#include <stdlib.h> +#include <iostream> +#include <pcap.h> +#include <cinttypes> +#include <sstream> +#include <iomanip> +#include "third-party/radiotap-library/radiotap.h" +#include "wifi-triangulator/core.h" + +using std::string; +using namespace wifi_triangulator::pb; + +namespace wifi_triangulator { + +struct ieee802_11_header { + uint8_t frame_1; + uint8_t frame_2; + uint16_t duration_id; + + eth_mac addr1, addr2, addr3; + uint16_t seq_ctl; + eth_mac addr4; + + bool is_to_ds() const { + return (frame_2 & 0x80) > 0; + } + + bool is_from_ds() const { + return (frame_2 & 0x40) > 0; + } +} __attribute__ ((packed)); + +struct radio_tap_it { + radio_tap_it(const uint8_t *data) : offset(0), data(data) { + } + + const uint8_t *data; + int offset; + + uint8_t read8u() { + uint8_t value = data[offset]; + offset += 1; + return value; + } + + int8_t read8s() { + int8_t value = data[offset]; + offset += 1; + return value; + } + + uint16_t read16u() { + uint16_t value = *reinterpret_cast<const uint16_t *>(&data[offset]); + offset += 2; + offset = (offset + (2 - 1)) & -2; + return value; + } + + uint32_t read32u() { + uint32_t value = *reinterpret_cast<const uint32_t *>(&data[offset]); + offset += 4; + offset = (offset + (4 - 1)) & -4; + return value; + } + + uint64_t read64u() { + uint64_t value = *reinterpret_cast<const uint64_t *>(&data[offset]); + offset += 8; + offset = (offset + (8 - 1)) & -8; + return value; + } +}; + +struct capture_context { + std::function<void( const data &)> data_consumer; +}; + +void got_packet(u_char *args, const struct pcap_pkthdr *header, const u_char *packet) { +// fprintf(stdout, "%lu.%lu, caplen=%d, len=%d\n", header->ts.tv_sec, header->ts.tv_usec, header->caplen, header->len); + + auto *ctx = reinterpret_cast<capture_context *>(args); + auto *rtaphdr = reinterpret_cast<const struct ieee80211_radiotap_header *>(packet); + + if (rtaphdr->it_version != 0) { + return; + } + + int present_count = 0; + { + auto *present_ptr = &rtaphdr->it_present; + do { + present_count++; + } while ((*present_ptr++) & 1 << IEEE80211_RADIOTAP_EXT); + } + + radio_tap_it it(packet + 4 + 4 * present_count); + + auto *present_ptr = &rtaphdr->it_present; + bool is_radiotap = true; + int rssi = 0; + do { + uint32_t present = *present_ptr; + bool next_is_radiotap = (present & 1 << IEEE80211_RADIOTAP_RADIOTAP_NAMESPACE) != 0; + // printf("present: %08x\n", present); + + present &= ~(1 << IEEE80211_RADIOTAP_RADIOTAP_NAMESPACE); + present &= ~(1 << IEEE80211_RADIOTAP_VENDOR_NAMESPACE); + present &= ~(1 << IEEE80211_RADIOTAP_EXT); + + if (is_radiotap) { + char buf[101]; + + if (present & 1 << IEEE80211_RADIOTAP_TSFT) { + auto tsft = it.read64u(); + snprintf(buf, 100, "IEEE80211_RADIOTAP_TSFT: %" PRIu64 "\n", tsft); + present &= ~(1 << IEEE80211_RADIOTAP_TSFT); + } + if (present & 1 << IEEE80211_RADIOTAP_FLAGS) { + uint8_t flags = it.read8u(); + snprintf(buf, 100, "IEEE80211_RADIOTAP_FLAGS: %02x\n", flags); + present &= ~(1 << IEEE80211_RADIOTAP_FLAGS); + } + if (present & 1 << IEEE80211_RADIOTAP_RATE) { + uint8_t rate = it.read8u(); + + double r = rate / 2; + snprintf(buf, 100, "IEEE80211_RADIOTAP_RATE: %.1lf\n", r); + present &= ~(1 << IEEE80211_RADIOTAP_RATE); + } + if (present & 1 << IEEE80211_RADIOTAP_CHANNEL) { + uint16_t mhz = it.read16u(); + uint16_t bitmap = it.read16u(); + + snprintf(buf, 100, "IEEE80211_RADIOTAP_CHANNEL: %d MHz, flags=%04x\n", mhz, bitmap); + present &= ~(1 << IEEE80211_RADIOTAP_CHANNEL); + } + if (present & 1 << IEEE80211_RADIOTAP_FHSS) { + uint8_t hop_set = it.read8u(); + uint8_t pattern = it.read8u(); + + snprintf(buf, 100, "IEEE80211_RADIOTAP_FHSS: hop_set=%02x, pattern=%02x\n", hop_set, pattern); + present &= ~(1 << IEEE80211_RADIOTAP_FHSS); + } + if (present & 1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL) { + int8_t antsignal_dbm = it.read8s(); + + rssi = antsignal_dbm; + snprintf(buf, 100, "IEEE80211_RADIOTAP_DBM_ANTSIGNAL: dbm=%d\n", antsignal_dbm); + present &= ~(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL); + } + if (present & 1 << IEEE80211_RADIOTAP_DBM_ANTNOISE) { + int8_t antnoise_dbm = it.read8s(); + + snprintf(buf, 100, "IEEE80211_RADIOTAP_DBM_ANTNOISE: dbm=%d\n", antnoise_dbm); + present &= ~(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE); + } + if (present & 1 << IEEE80211_RADIOTAP_LOCK_QUALITY) { + uint16_t lock_quality = it.read16u(); + + snprintf(buf, 100, "IEEE80211_RADIOTAP_LOCK_QUALITY: lock_quality=%d\n", lock_quality); + present &= ~(1 << IEEE80211_RADIOTAP_LOCK_QUALITY); + } + if (present & 1 << IEEE80211_RADIOTAP_TX_ATTENUATION) { + uint16_t tx_attenuation = it.read16u(); + + snprintf(buf, 100, "IEEE80211_RADIOTAP_TX_ATTENUATION: tx_attenuation=%d\n", tx_attenuation); + present &= ~(1 << IEEE80211_RADIOTAP_TX_ATTENUATION); + } + if (present & 1 << IEEE80211_RADIOTAP_DB_TX_ATTENUATION) { + uint16_t db_tx_attenuation = it.read16u(); + + snprintf(buf, 100, "IEEE80211_RADIOTAP_DB_TX_ATTENUATION: db_tx_attenuation=%d\n", db_tx_attenuation); + present &= ~(1 << IEEE80211_RADIOTAP_DB_TX_ATTENUATION); + } + if (present & 1 << IEEE80211_RADIOTAP_DBM_TX_POWER) { + int8_t tx_power_dbm = it.read8s(); + + snprintf(buf, 100, "IEEE80211_RADIOTAP_DBM_TX_POWER: tx_power_dbm=%d\n", tx_power_dbm); + present &= ~(1 << IEEE80211_RADIOTAP_DBM_TX_POWER); + } + if (present & 1 << IEEE80211_RADIOTAP_ANTENNA) { + uint8_t antenna = it.read8u(); + + snprintf(buf, 100, "IEEE80211_RADIOTAP_ANTENNA: antenna=%d\n", antenna); + present &= ~(1 << IEEE80211_RADIOTAP_ANTENNA); + } + if (present & 1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL) { + uint8_t antenna_signal_db = it.read8u(); + + snprintf(buf, 100, "IEEE80211_RADIOTAP_DB_ANTSIGNAL: antenna_signal_db=%d\n", antenna_signal_db); + present &= ~(1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL); + } + if (present & 1 << IEEE80211_RADIOTAP_DB_ANTNOISE) { + uint8_t antenna_noise_db = it.read8u(); + + snprintf(buf, 100, "IEEE80211_RADIOTAP_DB_ANTNOISE: antenna_noise_db=%d\n", antenna_noise_db); + present &= ~(1 << IEEE80211_RADIOTAP_DB_ANTNOISE); + } + if (present & 1 << IEEE80211_RADIOTAP_RX_FLAGS) { + uint16_t rx_flags = it.read16u(); + + snprintf(buf, 100, "IEEE80211_RADIOTAP_RX_FLAGS: rx_flags=%d\n", rx_flags); + present &= ~(1 << IEEE80211_RADIOTAP_RX_FLAGS); + } + if (present & 1 << IEEE80211_RADIOTAP_TX_FLAGS) { + uint16_t tx_flags = it.read16u(); + + snprintf(buf, 100, "IEEE80211_RADIOTAP_TX_FLAGS: tx_flags=%d\n", tx_flags); + present &= ~(1 << IEEE80211_RADIOTAP_TX_FLAGS); + } + + if (present > 0) { + snprintf(buf, 100, "Unknown fields remain: %08x\n", present); + break; + } + +// printf(buf); + /* + int bit = 0; + uint32_t mask = 1; + for (int i = 0; i < 29; i++) { + if (present & mask) { + printf("bit %d\n", bit); + } + + bit++; + mask <<= 1; + } + */ + } + is_radiotap = next_is_radiotap; + } while ((*present_ptr++) & 1 << IEEE80211_RADIOTAP_EXT); + + const struct ieee802_11_header *ieee802_11_header = reinterpret_cast<const struct ieee802_11_header *>(&packet[rtaphdr->it_len]); + + uint8_t type = ieee802_11_header->frame_1; + + packet_type t; + switch (type) { + case 0x40: + t = packet_type::probe_request; + break; + case 0x80: + t = packet_type::beacon; + break; + case 0x50: + t = packet_type::probe_response; + break; + case 0x48: + t = packet_type::null; + break; + case 0xd4: + t = packet_type::ack; + break; + case 0x08: + t = packet_type::data; + break; + case 0xc4: + t = packet_type::cts; + break; + case 0xb4: + t = packet_type::rts; + break; + case 0x1e: + t = packet_type::cf_end; + break; + case 0x1f: + t = packet_type::cf_end_cf_ack; + break; + case 0x1a: + t = packet_type::ps_poll; + break; + default: + t = packet_type::unknown; + } + +// printf("ieee802_11_header->frame_ctl=%02x, %s\n", type, type_str ? type_str : "???"); + + eth_mac src, dst; + + if (!ieee802_11_header->is_from_ds()) { + if (!ieee802_11_header->is_to_ds()) { + dst = ieee802_11_header->addr1; + src = ieee802_11_header->addr2; + } else { + dst = ieee802_11_header->addr1; + src = ieee802_11_header->addr3; + } + } else { + if (!ieee802_11_header->is_to_ds()) { + dst = ieee802_11_header->addr3; + src = ieee802_11_header->addr2; + } else { + dst = ieee802_11_header->addr3; + src = ieee802_11_header->addr4; + } + } + + ctx->data_consumer(data{ + t, + header->ts.tv_sec, header->ts.tv_usec, + rssi, src, dst}); +} + +int launch_capture(string dev, std::function<void(const class data &)> data_consumer) { + char errbuf[1000]; + + pcap_t *handle; + + handle = pcap_open_live(dev.c_str(), BUFSIZ, 1, 1000, errbuf); +// handle = pcap_open_offline(dev, errbuf); + + if (!handle) { + fprintf(stderr, + "Could not open %s: %s\n", dev. + + c_str(), errbuf + + ); + return EXIT_FAILURE; + } + + int i = pcap_datalink(handle); + if (i != DLT_IEEE802_11_RADIO) { + fprintf(stderr, + "Device %s doesn't provide IEEE 802.11 radio headers\n", dev. + + c_str() + + ); + return EXIT_FAILURE; + } + +/* Compile and apply the filter */ +// if (pcap_compile(handle, &fp, filter_exp, 0, net) == -1) { +// fprintf(stderr, "Couldn't parse filter %s: %s\n", filter_exp, pcap_geterr(handle)); +// return EXIT_FAILURE; +// } +// if (pcap_setfilter(handle, &fp) == -1) { +// fprintf(stderr, "Couldn't install filter %s: %s\n", filter_exp, pcap_geterr(handle)); +// return EXIT_FAILURE; +// } + + capture_context ctx{data_consumer}; + while (true) { + auto ret = pcap_loop(handle, 1000, got_packet, reinterpret_cast<u_char *>(&ctx)); + + if (ret == -1) { + printf("pcap failed: %s\n", + pcap_geterr(handle) + ); + break; + } else if (ret == -2) { +// someone called break loop + break; + } + } + + pcap_close(handle); + + return EXIT_SUCCESS; +} + +} // namespace wifi_triangulator |