Fix camd message len

Fixes problems with providers that use quite long ECMs/EMMs.

Store message len in int instead of uint8_t to fix transmission of msgs
longer than 255 bytes (size_t was not an option as some functions return
negative values).

Add msg len check to cs378x as it only allows up to 256 bytes data.

camd-cs378x.c

@@ -50,7 +50,7 @@ static int cs378x_recv(struct camd *c, uint8_t *data, int *data_len) {
 			c->ops.ident, auth_token, c->cs378x.auth_token);
 	}
 
-	*data_len = 256;
+	*data_len = CAMD35_DATA_SIZE;
 	for (i = 0; i < *data_len; i += 16) { // Read and decrypt payload
 		fdread(c->server_fd, (char *)data + i, 16);
 		AES_decrypt(data + i, data + i, &c->cs378x.aes_decrypt_key);
@@ -96,9 +96,14 @@ static void cs378x_buf_init(struct camd *c, uint8_t *data, int data_len) {
 }
 
 static int cs378x_do_ecm(struct camd *c, struct camd_msg *msg) {
+	if (msg->data_len > CAMD35_DATA_SIZE) {
+		ts_LOGf("ERR | [%s] Data too long.\n", c->ops.ident);
+		return 0; // false
+	}
+
 	int to_send = boundary(4, CAMD35_HDR_LEN + msg->data_len);
 
-	cs378x_buf_init(c, msg->data, (int)msg->data_len);
+	cs378x_buf_init(c, msg->data, msg->data_len);
 
 	c->cs378x.msg_id++;
 

camd.c

@@ -238,7 +238,7 @@ OUT:
 	camd_msg_free(&msg);
 }
 
-struct camd_msg *camd_msg_alloc(enum msg_type msg_type, uint16_t ca_id, uint16_t service_id, uint8_t *data, uint8_t data_len) {
+struct camd_msg *camd_msg_alloc(enum msg_type msg_type, uint16_t ca_id, uint16_t service_id, uint8_t *data, int data_len) {
 	struct camd_msg *c = calloc(1, sizeof(struct camd_msg));
 	c->type       = msg_type;
 	c->ca_id      = ca_id;

camd.h

@@ -19,7 +19,7 @@
 
 int connect_client							(int socktype, const char *hostname, const char *service);
 
-struct camd_msg *		camd_msg_alloc		(enum msg_type msg_type, uint16_t ca_id, uint16_t service_id, uint8_t *data, uint8_t data_len);
+struct camd_msg *		camd_msg_alloc		(enum msg_type msg_type, uint16_t ca_id, uint16_t service_id, uint8_t *data, int data_len);
 void					camd_msg_free   	(struct camd_msg **pmsg);
 
 void					camd_set_cw			(struct ts *ts, uint8_t *new_cw, int check_validity);

data.h

@@ -72,7 +72,8 @@ struct key {
 
 // 4 auth header, 20 header size, 256 max data size, 16 potential padding
 #define CAMD35_HDR_LEN (20)
-#define CAMD35_BUF_LEN (4 + CAMD35_HDR_LEN + 256 + 16)
+#define CAMD35_DATA_SIZE (256)
+#define CAMD35_BUF_LEN (4 + CAMD35_HDR_LEN + CAMD35_DATA_SIZE + 16)
 
 // When this limit is reached invalid_cw flag is set.
 #define ECM_RECV_ERRORS_LIMIT 10
@@ -89,8 +90,8 @@ struct camd_msg {
 	enum msg_type	type;
 	uint16_t		ca_id;
 	uint16_t		service_id;
-	uint8_t			data_len;
-	uint8_t			data[255];
+	int				data_len;
+	uint8_t			data[512];	// enough for now
 	struct ts		*ts;
 };