net/coap: add generic get block function

sys/include/net/nanocoap.h

@@ -631,6 +631,26 @@ size_t coap_blockwise_put_bytes(coap_block_slicer_t *slicer, uint8_t *bufpos,
  */
 size_t coap_blockwise_put_char(coap_block_slicer_t *slicer, uint8_t *bufpos, char c);
 
+/**
+ * @brief    Block option getter
+ *
+ * This function gets a CoAP packet's block option and parses it into a helper
+ * structure.
+ *
+ * If no block option is present in @p pkt, the values in @p block will be
+ * initialized with zero. That implies both block->offset and block->more are
+ * also valid in that case, as packet with offset==0 and more==0 means it contains
+ * all the payload for the corresponding request.
+ *
+ * @param[in]   pkt     pkt to work on
+ * @param[out]  block   ptr to preallocated coap_block1_t structure
+ * @param[in]   option  block1 or block2
+ *
+ * @returns     0 if block option not present
+ * @returns     1 if structure has been filled
+ */
+int coap_get_block(coap_pkt_t *pkt, coap_block1_t *block, uint16_t option);
+
 /**
  * @brief    Block1 option getter
  *
@@ -643,23 +663,29 @@ size_t coap_blockwise_put_char(coap_block_slicer_t *slicer, uint8_t *bufpos, cha
  * all the payload for the corresponding request.
  *
  * @param[in]   pkt     pkt to work on
- * @param[out]  block1  ptr to preallocated coap_block1_t structure
+ * @param[out]  block   ptr to preallocated coap_block1_t structure
  *
  * @returns     0 if block1 option not present
  * @returns     1 if structure has been filled
  */
-int coap_get_block1(coap_pkt_t *pkt, coap_block1_t *block1);
+static inline int coap_get_block1(coap_pkt_t *pkt, coap_block1_t *block)
+{
+    return coap_get_block(pkt, block, COAP_OPT_BLOCK1);
+}
 
 /**
  * @brief    Block2 option getter
  *
  * @param[in]   pkt     pkt to work on
- * @param[out]  block2  ptr to preallocated coap_block1_t structure
+ * @param[out]  block   ptr to preallocated coap_block1_t structure
  *
  * @returns     0 if block2 option not present
  * @returns     1 if structure has been filled
  */
-int coap_get_block2(coap_pkt_t *pkt, coap_block1_t *block2);
+static inline int coap_get_block2(coap_pkt_t *pkt, coap_block1_t *block)
+{
+    return coap_get_block(pkt, block, COAP_OPT_BLOCK2);
+}
 
 /**
  * @brief    Generic block option getter

sys/net/application_layer/nanocoap/nanocoap.c

@@ -599,30 +599,17 @@ static unsigned _slicer2blkopt(coap_block_slicer_t *slicer, bool more)
     return (blknum << 4) | _size2szx(blksize) | (more ? 0x8 : 0);
 }
 
-int coap_get_block1(coap_pkt_t *pkt, coap_block1_t *block1)
+int coap_get_block(coap_pkt_t *pkt, coap_block1_t *block, uint16_t option)
 {
-    uint32_t blknum;
-    unsigned szx;
-
-    block1->more = coap_get_blockopt(pkt, COAP_OPT_BLOCK1, &blknum, &szx);
-    if (block1->more >= 0) {
-        block1->offset = blknum << (szx + 4);
+    block->more = coap_get_blockopt(pkt, option, &block->blknum, &block->szx);
+    if (block->more >= 0) {
+        block->offset = block->blknum << (block->szx + 4);
     }
     else {
-        block1->offset = 0;
+        block->offset = 0;
     }
 
-    block1->blknum = blknum;
-    block1->szx = szx;
-
-    return (block1->more >= 0);
-}
-
-int coap_get_block2(coap_pkt_t *pkt, coap_block1_t *block2)
-{
-    block2->more = coap_get_blockopt(pkt, COAP_OPT_BLOCK2, &block2->blknum,
-                                     &block2->szx);
-    return (block2->more >= 0);
+    return (block->more >= 0);
 }
 
 size_t coap_put_block1_ok(uint8_t *pkt_pos, coap_block1_t *block1, uint16_t lastonum)