nfc: add debug PCAP output, refactor Mifare DESFire following #1095 (#1294)

* nfc: refactor nfc_worker_read_mifare_desfire to use furi_hal_nfc_tx_rx
  Renames furi_hal_nfc_exchange_full to furi_hal_nfc_tx_rx_full, and
  rewrites it to use furi_hal_nfc_tx_rx.  This eliminates the final
  remaining use of furi_hal_nfc_exchange, so remove that.
* nfc: write debug.pcap when debug mode enabled
  Limited to NFC protocols that use furi_hal_nfc_tx_rx to communicate.
* switch to Doxygen style comment

Co-authored-by: Kevin Wallace <git+flipperzero@kevin.wallace.seattle.wa.us>
Co-authored-by: あく <alleteam@gmail.com>

applications/nfc/helpers/nfc_debug_pcap.c

@@ -0,0 +1,99 @@
+#include "nfc_debug_pcap.h"
+
+#include <furi_hal_rtc.h>
+
+#define TAG "NfcDebugPcap"
+
+#define PCAP_MAGIC 0xa1b2c3d4
+#define PCAP_MAJOR 2
+#define PCAP_MINOR 4
+#define DLT_ISO_14443 264
+
+#define DATA_PICC_TO_PCD 0xFF
+#define DATA_PCD_TO_PICC 0xFE
+#define DATA_PICC_TO_PCD_CRC_DROPPED 0xFB
+#define DATA_PCD_TO_PICC_CRC_DROPPED 0xFA
+
+File* nfc_debug_pcap_open(Storage* storage) {
+    File* file = storage_file_alloc(storage);
+    if(!storage_file_open(file, "/ext/nfc/debug.pcap", FSAM_WRITE, FSOM_OPEN_APPEND)) {
+        storage_file_free(file);
+        return NULL;
+    }
+    if(!storage_file_tell(file)) {
+        struct {
+            uint32_t magic;
+            uint16_t major, minor;
+            uint32_t reserved[2];
+            uint32_t snaplen;
+            uint32_t link_type;
+        } __attribute__((__packed__)) pcap_hdr = {
+            .magic = PCAP_MAGIC,
+            .major = PCAP_MAJOR,
+            .minor = PCAP_MINOR,
+            .snaplen = FURI_HAL_NFC_DATA_BUFF_SIZE,
+            .link_type = DLT_ISO_14443,
+        };
+        if(storage_file_write(file, &pcap_hdr, sizeof(pcap_hdr)) != sizeof(pcap_hdr)) {
+            FURI_LOG_E(TAG, "Failed to write pcap header");
+        }
+    }
+    return file;
+}
+
+void nfc_debug_pcap_write(Storage* storage, uint8_t event, uint8_t* data, uint16_t len) {
+    File* file = nfc_debug_pcap_open(storage);
+    if(!file) return;
+
+    FuriHalRtcDateTime datetime;
+    furi_hal_rtc_get_datetime(&datetime);
+
+    struct {
+        // https://wiki.wireshark.org/Development/LibpcapFileFormat#record-packet-header
+        uint32_t ts_sec;
+        uint32_t ts_usec;
+        uint32_t incl_len;
+        uint32_t orig_len;
+        // https://www.kaiser.cx/posts/pcap-iso14443/#_packet_data
+        uint8_t version;
+        uint8_t event;
+        uint16_t len;
+    } __attribute__((__packed__)) pkt_hdr = {
+        .ts_sec = furi_hal_rtc_datetime_to_timestamp(&datetime),
+        .ts_usec = 0,
+        .incl_len = len + 4,
+        .orig_len = len + 4,
+        .version = 0,
+        .event = event,
+        .len = len << 8 | len >> 8,
+    };
+    if(storage_file_write(file, &pkt_hdr, sizeof(pkt_hdr)) != sizeof(pkt_hdr)) {
+        FURI_LOG_E(TAG, "Failed to write pcap packet header");
+    } else if(storage_file_write(file, data, len) != len) {
+        FURI_LOG_E(TAG, "Failed to write pcap packet data");
+    }
+    storage_file_free(file);
+}
+
+void nfc_debug_pcap_write_tx(uint8_t* data, uint16_t bits, bool crc_dropped, void* context) {
+    uint8_t event = crc_dropped ? DATA_PCD_TO_PICC_CRC_DROPPED : DATA_PCD_TO_PICC;
+    nfc_debug_pcap_write(context, event, data, bits / 8);
+}
+
+void nfc_debug_pcap_write_rx(uint8_t* data, uint16_t bits, bool crc_dropped, void* context) {
+    uint8_t event = crc_dropped ? DATA_PICC_TO_PCD_CRC_DROPPED : DATA_PICC_TO_PCD;
+    nfc_debug_pcap_write(context, event, data, bits / 8);
+}
+
+void nfc_debug_pcap_prepare_tx_rx(FuriHalNfcTxRxContext* tx_rx, Storage* storage, bool is_picc) {
+    if(furi_hal_rtc_is_flag_set(FuriHalRtcFlagDebug)) {
+        if(is_picc) {
+            tx_rx->sniff_tx = nfc_debug_pcap_write_rx;
+            tx_rx->sniff_rx = nfc_debug_pcap_write_tx;
+        } else {
+            tx_rx->sniff_tx = nfc_debug_pcap_write_tx;
+            tx_rx->sniff_rx = nfc_debug_pcap_write_rx;
+        }
+        tx_rx->sniff_context = storage;
+    }
+}

applications/nfc/helpers/nfc_debug_pcap.h

@@ -0,0 +1,12 @@
+#pragma once
+
+#include <furi_hal_nfc.h>
+#include <storage/storage.h>
+
+/** Prepare tx/rx context for debug pcap logging, if enabled.
+ *
+ * @param      tx_rx   TX/RX context to log
+ * @param      storage Storage to log to
+ * @param      is_picc if true, record Flipper as PICC, else PCD.
+ */
+void nfc_debug_pcap_prepare_tx_rx(FuriHalNfcTxRxContext* tx_rx, Storage* storage, bool is_picc);