sys/net/gcoap: get rid of API abuse

sys/include/net/nanocoap.h

@@ -355,6 +355,7 @@
 /* forward declarations */
 static inline uint8_t *coap_hdr_data_ptr(const coap_hdr_t *hdr);
 static inline size_t coap_hdr_get_token_len(const coap_hdr_t *hdr);
+static inline const void * coap_hdr_get_token(const coap_hdr_t *hdr);
 
 /**
  * @brief   Get resource path associated with a CoAP request
@@ -757,6 +758,28 @@
     return 0;
 }
 
+/**
+ * @brief       Get the Token of a CoAP over UDP (DTLS) packet
+ * @param[in]   hdr     CoAP over UDP header
+ * @return      The CoAP Token inside the packet that @p hdr belongs to
+ *
+ * @warning     This API is super goofy. It assumes that the packet is valid
+ *              and will read more than `sizeof(*hdr)` into the data `hdr`
+ *              points to while crossing fingers hard.
+ *
+ * @deprecated  This function was introduced to keep legacy code alive.
+ *              Introducing new callers should be avoided. In the RX path an
+ *              @ref coap_pkt_t will be available, so that you can call
+ *              @ref coap_get_token instead. In the TX path the token was
+ *              added by us, so we really should know.
+ */
+static inline const void * coap_hdr_get_token(const coap_hdr_t *hdr)
+{
+    uint8_t *token = (void *)hdr;
+    token += sizeof(*hdr) + coap_hdr_tkl_ext_len(hdr);
+    return token;
+}
+
 /**
  * @brief       Get the header length of a CoAP packet.
  *
@@ -1941,7 +1964,7 @@
  *
  * @returns     amount of bytes written to @p buf
  */
 size_t coap_put_option(uint8_t *buf, uint16_t lastonum, uint16_t onum, const void *odata, size_t olen);
 
 /**
  * @brief   Insert block1 option into buffer
@@ -2383,4 +2406,4 @@
 }
 #endif
 #endif /* NET_NANOCOAP_H */
 /** @} */

sys/net/application_layer/gcoap/gcoap.c

@@ -53,7 +53,7 @@
 #define NO_IMMEDIATE_REPLY (-1)
 
 /* End of the range to pick a random timeout */
 #define TIMEOUT_RANGE_END ((uint32_t)CONFIG_COAP_ACK_TIMEOUT_MS * CONFIG_COAP_RANDOM_FACTOR_1000 / 1000)
 
 /* Internal functions */
 static void *_event_loop(void *arg);
@@ -399,7 +399,7 @@
         /* but store the header to keep the token for Observe notifications */
         memcpy(memo->msg.hdr_buf, hdr, sizeof(hdr));
         /* no further retransmissions should be made and
            gcoap_request_memo_get_hdr() has to know how to get the header for Observe notifications */
         memo->send_limit = GCOAP_SEND_LIMIT_NON;
     }
 }
@@ -945,38 +945,35 @@
 static gcoap_request_memo_t* _find_req_memo_by_token(const sock_udp_ep_t *remote,
                                                      const uint8_t *token, size_t tkl)
 {
-    /* no need to initialize struct; we only care about buffer contents below */
-    coap_pkt_t memo_pdu_data;
-    coap_pkt_t *memo_pdu = &memo_pdu_data;
-
     for (int i = 0; i < CONFIG_GCOAP_REQ_WAITING_MAX; i++) {
         if (_coap_state.open_reqs[i].state == GCOAP_MEMO_UNUSED) {
             continue;
         }
 
         gcoap_request_memo_t *memo = &_coap_state.open_reqs[i];
-        memo_pdu->hdr = gcoap_request_memo_get_hdr(memo);
+        coap_hdr_t *hdr = gcoap_request_memo_get_hdr(memo);
 
         /* verbose debug to catch bugs with request/response matching */
 #if SOCK_HAS_IPV4
         DEBUG("Seeking memo for remote=%s, tkn=0x%02x%02x%02x%02x%02x%02x%02x%02x, tkl=%"PRIuSIZE"\n",
               ipv4_addr_to_str(_ipv6_addr_str, (ipv4_addr_t *)&remote->addr.ipv4,
                                IPV6_ADDR_MAX_STR_LEN),
               token[0], token[1], token[2], token[3], token[4], token[5], token[6], token[7],
               tkl);
 #else
         DEBUG("Seeking memo for remote=%s, tkn=0x%02x%02x%02x%02x%02x%02x%02x%02x, tkl=%"PRIuSIZE"\n",
               ipv6_addr_to_str(_ipv6_addr_str, (ipv6_addr_t *)&remote->addr.ipv6,
                                IPV6_ADDR_MAX_STR_LEN),
               token[0], token[1], token[2], token[3], token[4], token[5], token[6], token[7],
               tkl);
 #endif
 
-        if (coap_get_token_len(memo_pdu) != tkl) {
-            DEBUG("Token length mismatch %u\n", coap_get_token_len(memo_pdu));
+        size_t memo_tkl = coap_hdr_get_token_len(hdr);
+        if (memo_tkl != tkl) {
+            DEBUG("Token length mismatch %" PRIuSIZE "\n", memo_tkl);
             continue;
         }
-        const uint8_t *memo_token = coap_get_token(memo_pdu);
+        const uint8_t *memo_token = coap_hdr_get_token(hdr);
         if (memcmp(token, memo_token, tkl)) {
             DEBUG("Token mismatch 0x%02x%02x%02x%02x%02x%02x%02x%02x\n",
                   memo_token[0], memo_token[1], memo_token[2], memo_token[3],
@@ -1679,7 +1676,7 @@
     const coap_resource_t *resource = last_resource;
 
     while (listener) {
         if ((resource = _match_resource_path_iterator(listener, resource, (const uint8_t *)uri_path))) {
             *last_listener = listener;
             return resource;
         }
@@ -2106,4 +2103,4 @@
     event_post(&_queue, arg);
 }
 
 /** @} */