Tag data management skeleton

3 files changed, 95 insertions, 27 deletions

diff --git a/nfcommander.h b/nfcommander.h
index b4622a1..00f0fb8 100644
--- a/nfcommander.h
+++ b/nfcommander.h
@@ -17,6 +17,7 @@ typedef enum {
 #define FLAG_TAG_DATA_VALID 1
 #define FLAG_TAG_UNPROGRAMMED 2
 #define FLAG_TAG_LOCKED 4
+#define FLAG_TAG_READONLY 8
 #define TAG_STATUS_FLAGS ((FLAG_TAG_DATA_VALID | FLAG_TAG_UNPROGRAMMED | FLAG_TAG_LOCKED))
 
 typedef struct {
@@ -24,9 +25,14 @@ typedef struct {
 	nfc_tag_t type;
 	uint8_t uid_length;
 	uint8_t uid[10];
-	//storage
+	//storage info
 	size_t bytes_available;
 	size_t granularity;
+	//data
+	size_t static_length;
+	uint8_t* static_data;
+	size_t dynamic_length;
+	uint8_t* dynamic_data;
 } nfc_tag_info_t;
 
 typedef int (*reader_plugin_init)(void);
@@ -45,8 +51,13 @@ int core_manage_fd(int fd, int manage, notification_target_t system);
  * This API is to be called by reader backends to indicate presence of a tag.
  * This can be done as soon as the UID of the tag has been read (ie. before
  * reading EEPROM contents) to check whether the card has already been read.
- * If this API returns 1, a full read is requested and the nfc_tag_info_t should
- * be submitted again with the data fully read.
+ *
+ * If this API returns TAG_READ_REQUESTED, a full read is requested and the
+ * nfc_tag_info_t should be submitted again with the data fully read.
+ *
+ * If this API returns TAG_WRITE_REQUESTED, the nfc_tag_into_t has been filled
+ * with valid data pointers and sizes to be writen to the tag
  */
 #define TAG_READ_REQUESTED 1
-int reader_tag_present(uint8_t flags, nfc_tag_info_t tag);
+#define TAG_WRITE_REQUESTED 2
+int reader_tag_present(uint8_t flags, nfc_tag_info_t* tag);
diff --git a/reader.c b/reader.c
index 0ca56cf..5f1316b 100644
--- a/reader.c
+++ b/reader.c
@@ -13,8 +13,8 @@
 #define DEFAULT_POLL_TIMEOUT 1000
 #define MAX_TAGS 5
 
-#define FLAG_PRESENT 8
-#define FLAG_ACTIVE 16
+#define FLAG_PRESENT 16
+#define FLAG_ACTIVE 32
 
 static void* reader_module = NULL;
 static reader_plugin_handle reader_backend_handle = NULL;
@@ -92,12 +92,12 @@ static void reader_print_tag(nfc_tag_info_t tag){
 	switch(tag.type){
 		case tag_unset: type = "UNST"; break;
 		case tag_unknown: type = "UNKN"; break;
-		case tag_mifare1: type = "MFR1"; break;
+		case tag_mifare1: type = "MIFR"; break;
 		case tag_ntag: type = "NTAG"; break;
 		case tag_desfire: type = "DESF"; break;
 	}
 
-	printf("[%s", type);
+	printf("[%s:%lu", type, tag.bytes_available);
 	for(n = 0; n < tag.uid_length; n++){
 		printf(" %02X", tag.uid[n]);
 	}
@@ -111,6 +111,16 @@ static void reader_expire(){
 	}
 }
 
+static void tag_info_free(nfc_tag_info_t* tag){
+	free(tag->static_data);
+	tag->static_data = NULL;
+	tag->static_length = 0;
+
+	free(tag->dynamic_data);
+	tag->dynamic_data = NULL;
+	tag->dynamic_length = 0;
+}
+
 static int reader_process(){
 	size_t n = 0;
 	for(n = 0; n < MAX_TAGS; n++){
@@ -144,8 +154,8 @@ static int reader_process(){
 		}
 		else{
 			if(tags[n].flags & FLAG_ACTIVE){
-				//tag was removed
-				//TODO
+				//tag was removed - free any allocated members
+				tag_info_free(&(tags[n].info));
 				printf("Tag in slot %lu removed\n", n);
 			}
 
@@ -156,7 +166,7 @@ static int reader_process(){
 	return 0;
 }
 
-int reader_tag_present(uint8_t flags, nfc_tag_info_t tag){
+int reader_tag_present(uint8_t flags, nfc_tag_info_t* tag){
 	size_t n = 0;
 
 	//sanitize input flags
@@ -165,15 +175,15 @@ int reader_tag_present(uint8_t flags, nfc_tag_info_t tag){
 	//check if tag already known
 	for(n = 0; n < MAX_TAGS; n++){
 		if((tags[n].flags & (FLAG_PRESENT | FLAG_ACTIVE))
-				&& tags[n].info.uid_length == tag.uid_length
-				&& !memcmp(tags[n].info.uid, tag.uid, tag.uid_length)){
+				&& tags[n].info.uid_length == tag->uid_length
+				&& !memcmp(tags[n].info.uid, tag->uid, tag->uid_length)){
 			//mark still present
 			tags[n].flags |= FLAG_PRESENT;
 
 			//if full data submitted, copy in and set flags
 			if(!(tags[n].flags & TAG_STATUS_FLAGS)){
 				if(flags & TAG_STATUS_FLAGS){
-					memcpy(&(tags[n].info), &tag, sizeof(tag));
+					memcpy(&(tags[n].info), tag, sizeof(nfc_tag_info_t));
 					tags[n].flags |= flags;
 					return 0;
 				}
@@ -188,7 +198,7 @@ int reader_tag_present(uint8_t flags, nfc_tag_info_t tag){
 	for(n = 0; n < MAX_TAGS; n++){
 		if(!tags[n].flags){
 			tags[n].flags |= FLAG_PRESENT | flags;
-			memcpy(&(tags[n].info), &tag, sizeof(tag));
+			memcpy(&(tags[n].info), tag, sizeof(nfc_tag_info_t));
 			return (tags[n].flags & TAG_STATUS_FLAGS) ? 0 : TAG_READ_REQUESTED;
 		}
 	}
diff --git a/reader_yhy.c b/reader_yhy.c
index 41f20d8..92d5080 100644
--- a/reader_yhy.c
+++ b/reader_yhy.c
@@ -41,6 +41,60 @@ int handle(int fd){
 	return 0;
 }
 
+uint8_t read_ntag(nfc_tag_info_t* tag){
+	uint8_t data[16];
+	size_t bytes;
+
+	//read 16 bytes starting at block 2
+	//[0-3] UID, lock bytes
+	//[4-7] CC
+	//[8-11] Signature
+	//[12-15] Data block offsets & lengths
+	bytes = yhy_sync_read(reader_fd, 2, data, sizeof(data));
+	if(bytes != 16){
+		//read failed, probably not a usable tag
+		return FLAG_TAG_LOCKED;
+	}
+
+	//check for NTAG signature CC bytes
+	if(data[4] != 0xE1 || data[5] != 0x10 || data[7]){
+		return FLAG_TAG_LOCKED;
+	}
+
+	switch(data[6]){
+		case 0x12:
+			//NTAG213
+			tag->bytes_available = 144;
+			break;
+		case 0x3E:
+			//NTAG215
+			tag->bytes_available = 496;
+			break;
+		case 0x6D:
+			//NTAG216
+			tag->bytes_available = 872;
+			break;
+		default:
+			//unknown
+			return FLAG_TAG_LOCKED;
+	}
+
+	//TODO check lock bits
+
+	//check nfcommander signature
+	if(data[8] != 0xCB || data[9] != 'N' || data[10] != 'F' || data[11] != 'C'){
+		return FLAG_TAG_UNPROGRAMMED;
+	}
+
+	
+	return 0;
+}
+
+uint8_t read_mifare(nfc_tag_info_t* tag){
+	//TODO
+	return 0;
+}
+
 int scan(){
 	nfc_tag_info_t card = {
 		0
@@ -48,8 +102,7 @@ int scan(){
 
 	uint16_t atqa = 0;
 	uint8_t sak = 0;
-	uint8_t data[16];
-	uint8_t bytes;
+	uint8_t flags;
 
 	for(yhy_sync_request(reader_fd, 1, &atqa); atqa; yhy_sync_request(reader_fd, 0, &atqa)){
 		sak = 0;
@@ -63,7 +116,6 @@ int scan(){
 			card.type = tag_unknown;
 			if(atqa == 0x0044){
 				card.type = tag_ntag;
-				card.bytes_available = 140;
 				card.granularity = 4;
 			}
 			else{
@@ -85,20 +137,15 @@ int scan(){
 			}
 		}
 
-		if(reader_tag_present(0, card) == TAG_READ_REQUESTED){
+		if(reader_tag_present(0, &card) == TAG_READ_REQUESTED){
 			//read card data
 			if(card.type == tag_ntag){
-				//capability container in page 3, byte 2
-				//
-				//	//0x12 -> ntag213
-				//	//0x3e -> ntag215
-				//	//0x6d -> ntag216
-				//user data in pages 4 trough 39
-				bytes = yhy_sync_read(reader_fd, 3, data, sizeof(data));
+				flags = read_ntag(&card);
 			}
 			else if(card.type == tag_mifare1){
+				flags = read_mifare(&card);
 			}
-			reader_tag_present(FLAG_TAG_LOCKED, card);
+			reader_tag_present(flags, &card);
 		}
 
 		yhy_sync_hlta(reader_fd);