can/isotp: allow changing FC options at runtime

sys/can/conn/isotp.c

@@ -91,7 +91,7 @@ int conn_can_isotp_create(conn_can_isotp_t *conn, struct isotp_options *options,
     return 0;
 }
 
-int conn_can_isotp_bind(conn_can_isotp_t *conn)
+int conn_can_isotp_bind(conn_can_isotp_t *conn, struct isotp_fc_options *fc_options)
 {
     assert(conn != NULL);
     assert(conn->isotp.opt.tx_id != 0 || conn->isotp.opt.rx_id != 0);
@@ -126,7 +126,7 @@ int conn_can_isotp_bind(conn_can_isotp_t *conn)
         put_msg(conn, &msg);
     }
 
-    ret = isotp_bind(&conn->isotp, &entry, conn);
+    ret = isotp_bind(&conn->isotp, &entry, conn, fc_options);
     if (!ret) {
         conn->bound = 1;
     }

sys/can/isotp/isotp.c

@@ -33,18 +33,6 @@
 #define ENABLE_DEBUG (0)
 #include "debug.h"
 
-#ifndef CAN_ISOTP_BS
-#define CAN_ISOTP_BS 10
-#endif
-
-#ifndef CAN_ISOTP_STMIN
-#define CAN_ISOTP_STMIN 5
-#endif
-
-#ifndef CAN_ISOTP_WFTMAX
-#define CAN_ISOTP_WFTMAX 0
-#endif
-
 #ifndef CAN_ISOTP_MSG_QUEUE_SIZE
 #define CAN_ISOTP_MSG_QUEUE_SIZE 64
 #endif
@@ -792,7 +780,8 @@ int isotp_send(struct isotp *isotp, const void *buf, int len, int flags)
     return len;
 }
 
-int isotp_bind(struct isotp *isotp, can_reg_entry_t *entry, void *arg)
+int isotp_bind(struct isotp *isotp, can_reg_entry_t *entry, void *arg,
+               struct isotp_fc_options *fc_options)
 {
     int ret;
 
@@ -816,13 +805,13 @@ int isotp_bind(struct isotp *isotp, can_reg_entry_t *entry, void *arg)
     memset(&isotp->rx, 0, sizeof(struct tpcon));
     memset(&isotp->tx, 0, sizeof(struct tpcon));
 
-    isotp->rxfc.bs = CAN_ISOTP_BS;
+    isotp->rxfc.bs = fc_options ? fc_options->bs : CAN_ISOTP_BS;
-    isotp->rxfc.stmin = CAN_ISOTP_STMIN;
+    isotp->rxfc.stmin = fc_options ? fc_options->stmin : CAN_ISOTP_STMIN;
     isotp->rxfc.wftmax = 0;
 
     isotp->txfc.bs = 0;
     isotp->txfc.stmin = 0;
-    isotp->txfc.wftmax = CAN_ISOTP_WFTMAX;
+    isotp->txfc.wftmax = fc_options ? fc_options->wftmax : CAN_ISOTP_WFTMAX;
 
     isotp->entry.ifnum = entry->ifnum;
 #ifdef MODULE_CAN_MBOX

sys/include/can/conn/isotp.h

@@ -112,10 +112,10 @@ static inline void conn_can_isotp_init_slave(conn_can_isotp_t *master, conn_can_
  * @brief   ISOTP connection
  */
 typedef struct conn_can_isotp {
-    struct isotp isotp;  /**< ISO-TP connection */
+    struct isotp isotp; /**< ISO-TP connection */
-    int ifnum;           /**< interface number */
+    int ifnum;          /**< interface number */
-    int bound;           /**< 1 if connection is bound */
+    int bound;          /**< 1 if connection is bound */
-    mbox_t mbox;         /**< mbox */
+    mbox_t mbox;        /**< mbox */
     /** message queue */
     msg_t mbox_queue[CONN_CAN_ISOTP_MBOX_SIZE];
 } conn_can_isotp_t;
@@ -137,11 +137,12 @@ int conn_can_isotp_create(conn_can_isotp_t *conn, struct isotp_options *options,
  * @brief Bind a can isotp connection
  *
  * @param[inout] conn       ISO-TP connection
+ * @param[in] fc_options    ISO-TP flow control options, can be NULL for default parameters
  *
  * @return 0 on success
  * @return any other negative number in case of an error
  */
-int conn_can_isotp_bind(conn_can_isotp_t *conn);
+int conn_can_isotp_bind(conn_can_isotp_t *conn, struct isotp_fc_options *fc_options);
 
 /**
  * @brief  Close can isotp connection socket

sys/include/can/isotp.h

@@ -31,6 +31,26 @@ extern "C" {
 #include "xtimer.h"
 #include "net/gnrc/pktbuf.h"
 
+#ifndef CAN_ISOTP_BS
+/**
+ * @brief   Default Block Size for RX Flow Control frames
+ */
+#define CAN_ISOTP_BS        (10)
+#endif
+
+#ifndef CAN_ISOTP_STMIN
+/**
+ * @brief   Default STmin for RX Flow Control frames
+ */
+#define CAN_ISOTP_STMIN     (5)
+#endif
+
+#ifndef CAN_ISOTP_WFTMAX
+/**
+ * @brief   Default maximum WFT for TX Flow Control
+ */
+#define CAN_ISOTP_WFTMAX    (1)
+#endif
 
 /**
  * @brief The isotp_fc_options struct
@@ -160,11 +180,14 @@ int isotp_send(struct isotp *isotp, const void *buf, int len, int flags);
  * @param isotp           the channel to bind
  * @param entry           entry identifying the CAN ifnum and the upper layer
  *                        either by its pid or its mailbox
+ * @param fc_options      flow control parameters, bs and stmin for rx, wftmax for tx,
+ *                        if NULL, default values will be used
  * @param arg             upper layer private parameter
  *
  * @return 0 on success, < 0 on error
  */
-int isotp_bind(struct isotp *isotp, can_reg_entry_t *entry, void *arg);
+int isotp_bind(struct isotp *isotp, can_reg_entry_t *entry, void *arg,
+               struct isotp_fc_options *fc_options);
 
 /**
  * @brief Release a bound isotp channel

tests/conn_can/main.c

@@ -227,7 +227,7 @@ static int _bind_isotp(int argc, char **argv)
 #endif
     ret = conn_can_isotp_create(&conn_isotp[thread_nb], &isotp_opt, ifnum);
     if (ret == 0) {
-        ret = conn_can_isotp_bind(&conn_isotp[thread_nb]);
+        ret = conn_can_isotp_bind(&conn_isotp[thread_nb], NULL);
     }
     if (ret < 0) {
         puts("Error when binding connection");