o Initial import of pcap-based wifi scanner.

5 files changed, 388 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
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index 0000000..3e07682
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+build
+cmake-build-*
+.idea
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..6f93fa6
--- /dev/null
+++ b/.gitmodules
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+[submodule "third-party/radiotap-library"]
+	path = third-party/radiotap-library
+	url = https://github.com/radiotap/radiotap-library
diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..9712cca
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,13 @@
+cmake_minimum_required(VERSION 3.6)
+project(wifi_triangulator)
+
+set(CMAKE_CXX_STANDARD 14)
+
+set(SOURCE_FILES main.cpp
+        third-party/radiotap-library/radiotap.c
+        third-party/radiotap-library/radiotap.h
+        third-party/radiotap-library/radiotap_iter.h
+        third-party/radiotap-library/platform.h)
+add_executable(wifi_triangulator ${SOURCE_FILES})
+
+target_link_libraries(wifi_triangulator PUBLIC pcap)
diff --git a/main.cpp b/main.cpp
new file mode 100644
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--- /dev/null
+++ b/main.cpp
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+#include <stdlib.h>
+#include <iostream>
+#include <pcap.h>
+#include <cinttypes>
+#include <sstream>
+#include <iomanip>
+#include "third-party/radiotap-library/radiotap.h"
+
+struct eth_mac {
+    uint8_t a, b, c, d, e, f;
+
+    const std::string to_string() {
+        std::stringstream s;
+        s << std::hex << std::setw(2) << std::setfill('0')
+          << (int) a << ":"
+          << std::setw(2) << std::setfill('0') << (int) b << ":"
+          << std::setw(2) << std::setfill('0') << (int) c << ":"
+          << std::setw(2) << std::setfill('0') << (int) d << ":"
+          << std::setw(2) << std::setfill('0') << (int) e << ":"
+          << std::setw(2) << std::setfill('0') << (int) f;
+        return s.str();
+    }
+};
+
+class data {
+public:
+    time_t sec;
+    suseconds_t usec;
+
+    int rssi;
+    struct eth_mac src, dst;
+
+    data() : sec(0), usec(0), src(), rssi(), dst() {
+    }
+};
+
+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;
+    }
+};
+
+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);
+
+    struct ieee80211_radiotap_header *rtaphdr = (struct ieee80211_radiotap_header *) packet;
+
+    class data data;
+    data.sec = header->ts.tv_sec;
+    data.usec = header->ts.tv_usec;
+
+    if (rtaphdr->it_version != 0) {
+        return;
+    }
+
+    int present_count = 0;
+    {
+        uint32_t *present_ptr = &rtaphdr->it_present;
+        do {
+            present_count++;
+        } while ((*present_ptr++) & 1 << IEEE80211_RADIOTAP_EXT);
+    }
+
+    radio_tap_it it(packet + 4 + 4 * present_count);
+
+    uint32_t *present_ptr = &rtaphdr->it_present;
+    bool is_radiotap = true;
+    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();
+
+                data.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;
+
+    const char *type_str;
+    switch (type) {
+        case 0x40:
+            type_str = "probe request";
+            break;
+        case 0x80:
+            type_str = "beacon";
+            break;
+        case 0x50:
+            type_str = "probe response";
+            break;
+        case 0x48:
+            type_str = "null";
+            break;
+        case 0xd4:
+            type_str = "ack";
+            break;
+        case 0x08:
+            type_str = "data";
+            break;
+        case 0xc4:
+            type_str = "cts";
+            break;
+        case 0xb4:
+            type_str = "rts";
+            break;
+        case 0x1e:
+            type_str = "cf-end";
+            break;
+        case 0x1f:
+            type_str = "cf-end+cf-ack";
+            break;
+        case 0x1a:
+            type_str = "ps-poll";
+            break;
+        default:
+            type_str = nullptr;
+    }
+
+//    printf("ieee802_11_header->frame_ctl=%02x, %s\n", type, type_str ? type_str : "???");
+
+    if (!ieee802_11_header->is_from_ds()) {
+        if (!ieee802_11_header->is_to_ds()) {
+            data.dst = ieee802_11_header->addr1;
+            data.src = ieee802_11_header->addr2;
+        } else {
+            data.dst = ieee802_11_header->addr1;
+            data.src = ieee802_11_header->addr3;
+        }
+    } else {
+        if (!ieee802_11_header->is_to_ds()) {
+            data.dst = ieee802_11_header->addr3;
+            data.src = ieee802_11_header->addr2;
+        } else {
+            data.dst = ieee802_11_header->addr3;
+            data.src = ieee802_11_header->addr4;
+        }
+    }
+
+    auto src = data.src.to_string();
+    auto dst = data.dst.to_string();
+    printf("data: %lu.%lu, rssi=%d, src=%s, dst=%s\n", data.sec, data.usec, data.rssi, src.c_str(), dst.c_str());
+
+    fflush(stdout);
+}
+
+int main(int argc, char *argv[]) {
+    char *dev = argv[1];
+    char errbuf[1000];
+
+    pcap_t *handle;
+
+    handle = pcap_open_live(dev, BUFSIZ, 1, 1000, errbuf);
+//    handle = pcap_open_offline(dev, errbuf);
+
+    if (!handle) {
+        fprintf(stderr, "Could not open %s: %s\n", dev, 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);
+        return (2);
+    }
+
+    /* 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(2);
+//    }
+//    if (pcap_setfilter(handle, &fp) == -1) {
+//        fprintf(stderr, "Couldn't install filter %s: %s\n", filter_exp, pcap_geterr(handle));
+//        return(2);
+//    }
+
+    while (true) {
+        auto ret = pcap_loop(handle, 1000, got_packet, nullptr);
+
+        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 (0);
+}
diff --git a/third-party/radiotap-library b/third-party/radiotap-library
new file mode 160000
+Subproject 9fafde1c85e2705488b7fffdf6275b3889ec513