Increase cvend reliability

.gitignore

@@ -3,5 +3,6 @@ obj/
 .cache
 .build
 .config.old
+.gdb_history
 build.log
 include

Makefile

@@ -12,7 +12,7 @@ else
 	CFLAGS := $(CFLAGS) -lX11
 endif
 
-TARGETS := pm3-lvgl cvend_test audio_test
+TARGETS := pm3-lvgl cvend_test cvend_decode audio_test
 EXES := $(patsubst %,bin/%,$(TARGETS))
 SRCS := $(shell find src inc -type f -iname '*.c')
 OBJS := $(patsubst src/%.c,obj/%.o,$(patsubst inc/%.c,obj/lib/%.o,$(SRCS)))

extra/README.md

@@ -0,0 +1,3 @@
+These are pulled from the pm3 wiki.
+
+<https://wiki.pm3.dev/cvend#cvend_protocol_notes>

extra/startup-host.hex

@@ -0,0 +1,142 @@
+0x00
+0x00
+0xBC
+0x01
+0x00
+0xEA
+0x00
+0x02
+0xA6
+0x01
+0x00
+0x41
+0xDC
+0x3D
+0xA7
+0xBC
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+0x00
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+0xBC
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+0x00
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+0x01
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+0xDF
+0xE3
+0x6C
+0xB6
+0xBC
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+0xE4
+0x00
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+0x5D
+0x00
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+0x01
+0x01
+0xB1
+0x37
+0xE8
+0xB5
+0xBC
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+0x00
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+0x00
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+0x01
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+0xE2
+0xA4
+0x30
+0xBD
+0xBC
+0x06
+0x00
+0xAA
+0x00
+0x04
+0x1B
+0x69
+0xA2
+0x95
+0x6C
+0x48
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+0x5B
+0x0A
+0xBC
+0x07
+0x00
+0xE8
+0x00
+0x05
+0xF6
+0x04
+0xFE
+0x0A
+0x00
+0x00
+0x60
+0x4A
+0x73
+0xA7
+0xBC
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+0x00
+0x02
+0x00
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+0x0B
+0xBC
+0x09
+0x00
+0x98
+0x00
+0x1A
+0x67
+0x00
+0x12
+0x2F
+0x68
+0x6F
+0x6D
+0x65
+0x2F
+0x61
+0x70
+0x70
+0x30
+0x2F
+0x76
+0x65
+0x72
+0x73
+0x69
+0x6F
+0x6E
+0x00
+0x00
+0x00
+0x00
+0x00
+0x64
+0xF8
+0x78
+0x80
+0x2B

inc/cvend.h

@@ -77,11 +77,14 @@ typedef struct cvend_packet {
 
 const char *stringify_msg_type(uint8_t msg_type);
 
-void cvend_init(const char *path);
-cvend_packet *cvend_read();
-cvend_packet *cvend_read_type(uint8_t msg_type);
-void cvend_write(uint8_t msg_type, uint8_t *msg_data, uint16_t msg_len);
+void cvend_init();
+void cvend_lock();
+void cvend_unlock();
+cvend_packet *cvend_read(FILE *file);
+cvend_packet *cvend_read_type(FILE *file, uint8_t msg_type);
+void cvend_write(FILE *file, uint8_t msg_type, uint8_t *msg_data, uint16_t msg_len);
 void cvend_free(cvend_packet *packet);
 void print_packet(cvend_packet *packet);
+void print_packet_short(char *brief, cvend_packet *packet);
 
 #endif /* end of include guard: CVEND_H_WNGPTXM7 */

inc/nfc.h

@@ -6,7 +6,7 @@
 typedef void (*nfc_cb)(uint8_t status, uint8_t *version, uint16_t version_size,
 		       uint8_t *data, uint16_t data_size);
 
-void nfc_init(const char *path);
+void nfc_reset(const char *path);
 void *nfc_handle(void *data);
 
 #endif /* end of include guard: NFC_H_3196CYAP */

src/cvend.c

@@ -7,8 +7,6 @@
 #include "crc32.h"
 #include "cvend.h"
 
-const char *cvend_path;
-FILE *file;
 pthread_mutex_t cvend_mutex = PTHREAD_MUTEX_INITIALIZER;
 int last_seq = 0;
 
@@ -112,6 +110,14 @@ const char *stringify_msg_type(uint8_t msg_type)
 	}
 }
 
+void cvend_lock() {
+	pthread_mutex_lock(&cvend_mutex);
+}
+
+void cvend_unlock() {
+	pthread_mutex_unlock(&cvend_mutex);
+}
+
 void calc_hdr_crc(cvend_packet *packet)
 {
 	packet->magic = 0xbc;
@@ -128,25 +134,23 @@ void calc_msg_crc(cvend_packet *packet)
 		packet->msg_crc = 0;
 }
 
-void cvend_init(const char *path)
+void cvend_init()
 {
-	cvend_path = path;
-	file = fopen(path, "wb+");
 }
 
-cvend_packet *cvend_read()
+cvend_packet *cvend_read(FILE *file)
 {
-	pthread_mutex_lock(&cvend_mutex);
+	cvend_lock();
 	uint8_t buf = 0x00;
 	uint8_t res = 0;
 	while (buf != 0xbc) {
 		res = fread(&buf, 1, 1, file);
 		if (res == 0) {
-			fclose(file);
-			file = fopen(cvend_path, "wb+");
+			cvend_unlock();
+			return NULL;
 		}
 		if (buf != 0xbc) {
-			printf("bad magic char: %x\n", buf);
+			printf("[WARN] bad magic char: %x\n", buf);
 		}
 	}
 
@@ -159,35 +163,41 @@ cvend_packet *cvend_read()
 	fread(&packet->hdr_crc, 1, 1, file);
 
 	packet->msg_data = malloc(packet->msg_len);
-	fread(packet->msg_data, 1, packet->msg_len, file);
+	uint16_t read = fread(packet->msg_data, 1, packet->msg_len, file);
+	if (read < packet->msg_len) {
+		printf("[ERROR] bad packet length\n");
+		cvend_free(packet);
+		return NULL;
+	}
 	if (packet->msg_type & 0x80)
 		fread(&packet->msg_crc, 1, 4, file);
 	else
 		packet->msg_crc = 0;
-	pthread_mutex_unlock(&cvend_mutex);
+	cvend_unlock();
 
 	if (packet->msg_type != MTYPE_HEARTBEAT) {
-		printf("RECEIVED:\n");
-		print_packet(packet);
+		print_packet_short("received", packet);
 	}
 	return packet;
 }
 
-cvend_packet *cvend_read_type(uint8_t msg_type)
+cvend_packet *cvend_read_type(FILE *file, uint8_t msg_type)
 {
 	cvend_packet *packet = NULL;
 	do {
 		if (packet)
 			cvend_free(packet);
-		packet = cvend_read();
+		packet = cvend_read(file);
+		if (!packet)
+			return NULL;
 	} while (packet->msg_type != msg_type);
 	return packet;
 }
 
-void cvend_write(uint8_t msg_type, uint8_t *msg_data,
+void cvend_write(FILE *file, uint8_t msg_type, uint8_t *msg_data,
 		 uint16_t msg_len)
 {
-	pthread_mutex_lock(&cvend_mutex);
+	cvend_lock();
 	cvend_packet packet;
 	packet.seq = ++last_seq;
 	packet.flags = 0;
@@ -197,8 +207,7 @@ void cvend_write(uint8_t msg_type, uint8_t *msg_data,
 	calc_hdr_crc(&packet);
 	calc_msg_crc(&packet);
 
-	int res = fwrite(&packet.magic, 1, 1, file);
-	printf("wrote %i\n", res);
+	fwrite(&packet.magic, 1, 1, file);
 	fwrite(&packet.seq, 1, 1, file);
 	fwrite(&packet.flags, 1, 1, file);
 	fwrite(&packet.msg_type, 1, 1, file);
@@ -209,13 +218,14 @@ void cvend_write(uint8_t msg_type, uint8_t *msg_data,
 	if (packet.msg_type & 0x80)
 		fwrite(&packet.msg_crc, 1, 4, file);
 
-	pthread_mutex_unlock(&cvend_mutex);
-	printf("SENT:\n"); 
-	print_packet(&packet);
+	cvend_unlock();
+	print_packet_short("sent", &packet);
 }
 
 void cvend_free(cvend_packet *packet)
 {
+	if (!packet)
+		return;
 	free(packet->msg_data);
 	free(packet);
 }
@@ -238,3 +248,18 @@ void print_packet(cvend_packet *packet)
 	printf("\n");
 	printf("msg_crc  = %u\n\n", packet->msg_crc);
 }
+
+void print_packet_short(char *brief, cvend_packet *packet)
+{
+	printf("[INFO] (cvend) %s: ", brief); 
+	printf("%s ", stringify_msg_type(packet->msg_type));
+	printf("(%02X)", packet->msg_type);
+	printf(", ");
+	if (packet->msg_type == MTYPE_LOG) {
+		printf("%s", packet->msg_data);
+	} else {
+		for (uint16_t i = 0; i < packet->msg_len; i++)
+			printf("%02x ", packet->msg_data[i]);
+	}
+	printf("\n");
+}

src/cvend_decode.c

@@ -0,0 +1,22 @@
+#include "cvend.h"
+
+int main(int argc, char *argv[])
+{
+	const char *path = argc > 1 ? argv[1] : "extra/startup-reader.bin";
+	FILE *file = fopen(path, "rb");
+
+	if (!file) {
+		printf("Failed to open %s\n", path);
+		return 1;
+	}
+
+	cvend_init();
+
+	cvend_packet *packet = cvend_read(file);
+	while (packet) {
+		// print_packet(packet);
+		cvend_free(packet);
+		packet = cvend_read(file);
+	}
+	return 0;
+}

src/cvend_test.c

@@ -2,7 +2,7 @@
 
 int main(int argc, char *argv[])
 {
-	char *file = argc > 1 ? argv[1] : "/dev/ttymxc3";
+	FILE *file = fopen(argc > 1 ? argv[1] : "/dev/ttymxc3", "wb+");
 	uint8_t desfire_enable[] = { 0x00, CTYPE_DESFIRE, 0x01, FUNC_ENABLE };
 	// uint8_t desfire_get_version[] = { 0x60 };
 	uint8_t desfire_select_application[] = { 0x5a, 0xF2, 0x10, 0xE0 };
@@ -10,28 +10,28 @@ int main(int argc, char *argv[])
 	uint8_t desfire_read[] = { 0xbd, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
 	uint8_t desfire_free[] = { 0x6e };
 
-	cvend_init(file);
-	cvend_write(MTYPE_PROX_CARD_FUNCTION, desfire_enable, 4);
+	cvend_init();
+	cvend_write(file, MTYPE_PROX_CARD_FUNCTION, desfire_enable, 4);
 
 	while (1) {
 		cvend_packet *packet;
-		packet = cvend_read();
+		packet = cvend_read(file);
 
 		// if (packet->msg_type != MTYPE_HEARTBEAT)
 		print_packet(packet);
 
 		if (packet->msg_type == MTYPE_DESFIRE_READ) {
 			//cvend_write(MTYPE_DESFIRE_INTERACT, desfire_get_version, 1);
-			cvend_write(MTYPE_DESFIRE_COMMAND, desfire_select_application, 4);
+			cvend_write(file, MTYPE_DESFIRE_COMMAND, desfire_select_application, 4);
 			cvend_packet *response;
 			do {
-				response = cvend_read();
+				response = cvend_read(file);
 			} while (!response);
 			print_packet(response);
-			cvend_write(MTYPE_DESFIRE_COMMAND, desfire_fid_list, 1);
+			cvend_write(file, MTYPE_DESFIRE_COMMAND, desfire_fid_list, 1);
 			cvend_free(response);
-			cvend_write(MTYPE_DESFIRE_COMMAND, desfire_read, 8);
-			cvend_write(MTYPE_DESFIRE_COMMAND, desfire_free, 1);
+			cvend_write(file, MTYPE_DESFIRE_COMMAND, desfire_read, 8);
+			cvend_write(file, MTYPE_DESFIRE_COMMAND, desfire_free, 1);
 		}
 
 		cvend_free(packet);

src/nfc.c

@@ -1,23 +1,68 @@
 #include "cvend.h"
 #include <stdint.h>
+#include <stdlib.h>
 #include <unistd.h>
 #include <pthread.h>
+#include <poll.h>
 #include "nfc.h"
 
-void nfc_init(const char *path)
+FILE *nfc_stream = NULL;
+const char *nfc_path = NULL;
+
+void nfc_reset(const char *path)
 {
 	uint8_t desfire_enable[] = { 0x00, CTYPE_DESFIRE, 0x01, FUNC_ENABLE };
+	cvend_packet *packet;
+	struct pollfd stream_poll;
 
-	cvend_init(path);
-	cvend_write(MTYPE_PROX_CARD_FUNCTION, desfire_enable, 4);
+	if (nfc_stream)
+		fclose(nfc_stream);
+	nfc_stream = fopen(path, "wb+");
+
+	stream_poll.fd = fileno(nfc_stream);
+	stream_poll.events = POLLIN;
+
+	cvend_init();
+	printf("[INFO] checking for signs of life\n");
+	cvend_write(nfc_stream, MTYPE_STATUS, NULL, 0);
+	int status = poll(&stream_poll, 1, 1);
+	if (status) {
+		printf("[INFO] buffer active, checking status\n");
+		packet = cvend_read_type(nfc_stream, MTYPE_STATUS_REPLY);
+		if (!packet) {
+			printf("[ERROR] failed reading status\n");
+			exit(1);
+		}
+		printf("[INFO] cvend seems to be working\n");
+		cvend_free(packet);
+	} else {
+		printf("[INFO] waiting for startup\n");
+		packet = cvend_read_type(nfc_stream, MTYPE_STARTUP);
+		if (!packet) {
+			printf("[ERROR] stream closed before startup\n");
+			exit(1);
+		}
+		printf("[INFO] startup complete\n");
+		cvend_free(packet);
+	}
+
+	printf("[INFO] enabling desfire\n");
+	cvend_write(nfc_stream, MTYPE_PROX_CARD_FUNCTION, desfire_enable, 4);
+	packet = cvend_read_type(nfc_stream, MTYPE_PROX_CARD_FUNCTION_REPLY);
+	if (!packet) {
+		printf("[ERROR] failed to start desfire\n");
+		exit(1);
+	}
+	printf("[INFO] desfire enabled\n");
+	cvend_free(packet);
 }
 
 void *nfc_heartbeat(void *data)
 {
 	uint8_t heartbeat[2] = { 0x00, 0x00 };
 	while (1) {
-		cvend_write(MTYPE_STATUS, heartbeat, 2);
-		sleep(10);
+		cvend_write(nfc_stream, MTYPE_STATUS, heartbeat, 2);
+		sleep(1);
 	}
 	return NULL;
 }
@@ -33,34 +78,50 @@ void *nfc_handle(void *data)
 	uint8_t desfire_read[] = { 0xbd, 0x00, 0x00, 0x00,
 				   0x00, 0x00, 0x00, 0x00 };
 	while (1) {
-		cvend_packet *packet = cvend_read();
+		usleep(100);
+		cvend_packet *packet = cvend_read(nfc_stream);
+		cvend_packet *resp_version = NULL;
+		cvend_packet *resp_data = NULL;
+
+		if (!packet)
+			goto reset;
 
 		if (packet->msg_type != MTYPE_DESFIRE_READ) {
-			cvend_free(packet);
-			continue;
+			goto cleanup;
 		}
-		cvend_free(packet);
 
-		cvend_write(MTYPE_DESFIRE_COMMAND,
+		cvend_write(nfc_stream, MTYPE_DESFIRE_COMMAND,
 			    desfire_select_application, 4);
-		cvend_free(cvend_read_type(MTYPE_DESFIRE_COMMAND_REPLY));
+		cvend_free(cvend_read_type(nfc_stream,
+					   MTYPE_DESFIRE_COMMAND_REPLY));
 
-		cvend_write(MTYPE_DESFIRE_COMMAND, desfire_get_version,
-			    1);
-		cvend_packet *resp_version =
-			cvend_read_type(MTYPE_DESFIRE_COMMAND_REPLY);
+		cvend_write(nfc_stream, MTYPE_DESFIRE_COMMAND,
+			    desfire_get_version, 1);
+		resp_version = cvend_read_type(nfc_stream,
+					       MTYPE_DESFIRE_COMMAND_REPLY);
+		if (!resp_version)
+			goto reset;
 
-		if (resp_version->msg_len == 2 && resp_version->msg_data[1] == 0x6e) {
-			cvend_free(resp_version);
-			continue;
-		}
+		if (resp_version->msg_len == 2 &&
+		    resp_version->msg_data[1] == 0x6e)
+			goto cleanup;
+
+		cvend_write(nfc_stream, MTYPE_DESFIRE_COMMAND, desfire_read, 8);
+		resp_data = cvend_read_type(nfc_stream,
+					    MTYPE_DESFIRE_COMMAND_REPLY);
+		if (!resp_data)
+			goto reset;
 
-		cvend_write(MTYPE_DESFIRE_COMMAND, desfire_read, 8);
-		cvend_packet *resp_data =
-			cvend_read_type(MTYPE_DESFIRE_COMMAND_REPLY);
 		callback(resp_data->msg_data[0], resp_version->msg_data,
 			 resp_version->msg_len, resp_data->msg_data,
 			 resp_version->msg_len);
+		goto cleanup;
+
+reset:
+		nfc_reset("/dev/ttymxc3");
+
+cleanup:
+		cvend_free(packet);
 		cvend_free(resp_version);
 		cvend_free(resp_data);
 	}

src/pm3-lvgl.c

@@ -57,7 +57,7 @@ int main(int argc, char *argv[])
 	lv_linux_fbdev_set_file(display, "/dev/fb0");
 
 	pthread_t nfc_thread;
-	nfc_init("/dev/ttymxc3");
+	nfc_reset("/dev/ttymxc3");
 	pthread_create(&nfc_thread, NULL, nfc_handle, read_card);
 #else
 	display = lv_x11_window_create("LVGL X11 Simulation", 800, 480);