net/gcoap: add Uri-Query strings for requests

pkg/nanocoap/Makefile

@@ -1,6 +1,6 @@
 PKG_NAME=nanocoap
 PKG_URL=https://github.com/kaspar030/sock
-PKG_VERSION=1bba8bb16463914266dd5a04fe2a3eac4ee129ae
+PKG_VERSION=fc0a9470536bc760998827a6dc05d7dedf7b93ad
 PKG_LICENSE=LGPL-2.1
 
 .PHONY: all

sys/include/net/gcoap.h

@@ -242,9 +242,9 @@ extern "C" {
  * @brief   Size of the buffer used to write options, other than Uri-Path, in a
  *          request
  *
- * Accommodates Content-Format.
+ * Accommodates Content-Format and Uri-Queries
  */
-#define GCOAP_REQ_OPTIONS_BUF   (8)
+#define GCOAP_REQ_OPTIONS_BUF   (40)
 
 /**
  * @brief   Size of the buffer used to write options in a response
@@ -654,6 +654,23 @@ uint8_t gcoap_op_state(void);
  */
 int gcoap_get_resource_list(void *buf, size_t maxlen, uint8_t cf);
 
+/**
+ * @brief   Adds a single Uri-Query option to a CoAP request
+ *
+ * To add multiple Uri-Query options, simply call this function multiple times.
+ * The Uri-Query options will be added in the order those calls.
+ *
+ * @param[out] pdu      The package that is being build
+ * @param[in]  key      Key to add to the query string
+ * @param[in]  val      Value to assign to @p key (may be NULL)
+ *
+ * @pre     ((pdu != NULL) && (key != NULL))
+ *
+ * @return  overall length of new query string
+ * @return  -1 on error
+ */
+int gcoap_add_qstring(coap_pkt_t *pdu, const char *key, const char *val);
+
 #ifdef __cplusplus
 }
 #endif

sys/net/application_layer/coap/gcoap.c

@@ -440,16 +440,24 @@ static ssize_t _write_options(coap_pkt_t *pdu, uint8_t *buf, size_t len)
                 DEBUG("gcoap: _write_options: path does not start with '/'\n");
                 return -EINVAL;
             }
-            bufpos += coap_put_option_url(bufpos, last_optnum, (char *)&pdu->url[0]);
+            bufpos += coap_put_option_uri(bufpos, last_optnum, (char *)pdu->url,
+                                          COAP_OPT_URI_PATH);
             last_optnum = COAP_OPT_URI_PATH;
         }
     }
 
     /* Content-Format */
     if (pdu->content_type != COAP_FORMAT_NONE) {
         bufpos += coap_put_option_ct(bufpos, last_optnum, pdu->content_type);
-        /* uncomment when add an option after Content-Format */
-        /* last_optnum = COAP_OPT_CONTENT_FORMAT; */
+        last_optnum = COAP_OPT_CONTENT_FORMAT;
+    }
+
+    /* Uri-query for requests */
+    if (coap_get_code_class(pdu) == COAP_CLASS_REQ) {
+        bufpos += coap_put_option_uri(bufpos, last_optnum, (char *)pdu->qs,
+                                      COAP_OPT_URI_QUERY);
+        /* uncomment when further options are added below ... */
+        /* last_optnum = COAP_OPT_URI_QUERY; */
     }
 
     /* write payload marker */
@@ -602,6 +610,7 @@ int gcoap_req_init(coap_pkt_t *pdu, uint8_t *buf, size_t len, unsigned code,
 
     pdu->hdr = (coap_hdr_t *)buf;
     memset(pdu->url, 0, NANOCOAP_URL_MAX);
+    memset(pdu->qs, 0, NANOCOAP_QS_MAX);
 
     /* generate token */
 #if GCOAP_TOKENLEN
@@ -839,4 +848,28 @@ int gcoap_get_resource_list(void *buf, size_t maxlen, uint8_t cf)
     return (int)pos;
 }
 
+int gcoap_add_qstring(coap_pkt_t *pdu, const char *key, const char *val)
+{
+    size_t qs_len = strlen((char *)pdu->qs);
+    size_t key_len = strlen(key);
+    size_t val_len = (val) ? (strlen(val) + 1) : 0;
+
+    /* make sure if url_len + the new query string fit into the url buffer */
+    if ((qs_len + key_len + val_len + 2) >= NANOCOAP_QS_MAX) {
+        return -1;
+    }
+
+    pdu->qs[qs_len++] = '&';
+    memcpy(&pdu->qs[qs_len], key, key_len);
+    qs_len += key_len;
+    if (val) {
+        pdu->qs[qs_len++] = '=';
+        memcpy(&pdu->qs[qs_len], val, val_len);
+        qs_len += val_len;
+    }
+    pdu->qs[qs_len] = '\0';
+
+    return (int)qs_len;
+}
+
 /** @} */