hal/sm_io/modules/acq/*: add channel limit checking

This finishes the quick fix for github issue #21.

hal/sm_io/modules/acq/sm_io_acq_codes.h

@@ -30,6 +30,7 @@
 #define ACQ_NUM_SAMPLES_OOR             1   /* Number of samples out of range */
 #define ACQ_NOT_COMPLETED               2   /* Acquisition not completed */
 #define ACQ_BLOCK_OOR                   3   /* Block number out of range */
-#define ACQ_REPLY_END                   4   /* End marker */
+#define ACQ_NUM_CHAN_OOR                4   /* Channel number out of range */
+#define ACQ_REPLY_END                   5   /* End marker */
 
 #endif

hal/sm_io/modules/acq/sm_io_acq_exp.c

@@ -107,7 +107,7 @@ static void *_acq_data_acquire (void *owner, void *args)
     uint32_t chan = *(uint32_t *) zframe_data (zmsg_pop (*exp_msg->msg));
 
     /* number of samples required is out of the maximum limit */
-    if (num_samples >= SMIO_ACQ_HANDLER(self)->acq_buf[chan].max_samples) {
+    if (num_samples > SMIO_ACQ_HANDLER(self)->acq_buf[chan].max_samples-1) {
         DBE_DEBUG (DBG_SM_IO | DBG_LVL_WARN, "[sm_io:acq] data_acquire: "
                 "Number of samples required is out of the maximum limit\n");
 
@@ -118,6 +118,18 @@ static void *_acq_data_acquire (void *owner, void *args)
         goto err_smp_exceeded;
     }
 
+    /* channel required is out of the limit */
+    if (chan > SMIO_ACQ_NUM_CHANNELS-1) {
+        DBE_DEBUG (DBG_SM_IO | DBG_LVL_WARN, "[sm_io:acq] data_acquire: "
+                "Channel required is out of the maximum limit\n");
+
+        /* Message is:
+         * frame 0: error code      */
+        _send_client_response (ACQ_NUM_CHAN_OOR, 0, NULL, false,
+                self->worker, exp_msg->reply_to);
+        goto err_smp_exceeded;
+    }
+
     DBE_DEBUG (DBG_SM_IO | DBG_LVL_TRACE, "[sm_io:acq] data_acquire: "
             "Current acq params: number of samples = %u, channel = %u\n",
             num_samples, chan);