[cli] add support for CoAP URI queries in CLI requests (#10003)

New feature:

Added CoAP URI query processing functionality to CLI.

Solution:

URI string is checked for a '?' character. If found, the URI query
related part is moved to another string. Afterwards, the modified
`coapUri` string will contain only the path-related parts, and a
second string (`coapUriQuery`) will hold only the URI query related
parts. Then `coapUri` is passed to the original
`otCoapMessageAppendUriPathOptions()` method and `coapUriQuery` is
passed to a new method called `otCoapMessageAppendUriQueryOptions()`,
which - similarly to the other - splits the URI query part into more,
smaller pieces by the delimiter '&' and adds them as separate options
to the CoAP message making the request generated by this CLI function
RFC compliant.  If '?' is not found, everything is processed the old
way.

include/openthread/coap.h

@@ -608,6 +608,19 @@ otError otCoapMessageAppendObserveOption(otMessage *aMessage, uint32_t aObserve)
  */
 otError otCoapMessageAppendUriPathOptions(otMessage *aMessage, const char *aUriPath);
 
+/**
+ * Appends a Uri-Query option.
+ *
+ * @param[in,out]  aMessage   A pointer to the CoAP message.
+ * @param[in]      aUriQuery  A pointer to a NULL-terminated string.
+ *
+ * @retval OT_ERROR_NONE          Successfully appended the option.
+ * @retval OT_ERROR_INVALID_ARGS  The option type is not equal or greater than the last option type.
+ * @retval OT_ERROR_NO_BUFS       The option length exceeds the buffer size.
+ *
+ */
+otError otCoapMessageAppendUriQueryOptions(otMessage *aMessage, const char *aUriQuery);
+
 /**
  * Converts a CoAP Block option SZX field to the actual block size
  *

include/openthread/instance.h

@@ -53,7 +53,7 @@ extern "C" {
  * @note This number versions both OpenThread platform and user APIs.
  *
  */
-#define OPENTHREAD_API_VERSION (427)
+#define OPENTHREAD_API_VERSION (428)
 
 /**
  * @addtogroup api-instance

src/cli/cli_coap.cpp

@@ -583,7 +583,8 @@ otError Coap::ProcessRequest(Arg aArgs[], otCoapCode aCoapCode)
     otError       error   = OT_ERROR_NONE;
     otMessage    *message = nullptr;
     otMessageInfo messageInfo;
-    uint16_t      payloadLength = 0;
+    uint16_t      payloadLength    = 0;
+    char         *uriQueryStartPtr = nullptr;
 
     // Default parameters
     char         coapUri[kMaxUriLength] = "test";
@@ -682,7 +683,20 @@ otError Coap::ProcessRequest(Arg aArgs[], otCoapCode aCoapCode)
     }
 #endif
 
-    SuccessOrExit(error = otCoapMessageAppendUriPathOptions(message, coapUri));
+    uriQueryStartPtr = const_cast<char *>(StringFind(coapUri, '?'));
+
+    if (uriQueryStartPtr == nullptr)
+    {
+        // "?" doesn't present in URI --> contains only URI path parts
+        SuccessOrExit(error = otCoapMessageAppendUriPathOptions(message, coapUri));
+    }
+    else
+    {
+        // "?" presents in URI --> contains URI path AND URI query parts
+        *uriQueryStartPtr++ = '\0';
+        SuccessOrExit(error = otCoapMessageAppendUriPathOptions(message, coapUri));
+        SuccessOrExit(error = otCoapMessageAppendUriQueryOptions(message, uriQueryStartPtr));
+    }
 
 #if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE
     if (coapBlock)

src/core/api/coap_api.cpp

@@ -99,6 +99,11 @@ otError otCoapMessageAppendUriPathOptions(otMessage *aMessage, const char *aUriP
     return AsCoapMessage(aMessage).AppendUriPathOptions(aUriPath);
 }
 
+otError otCoapMessageAppendUriQueryOptions(otMessage *aMessage, const char *aUriQuery)
+{
+    return AsCoapMessage(aMessage).AppendUriQueryOptions(aUriQuery);
+}
+
 uint16_t otCoapBlockSizeFromExponent(otCoapBlockSzx aSize)
 {
     return static_cast<uint16_t>(1 << (static_cast<uint8_t>(aSize) + Coap::Message::kBlockSzxBase));

src/core/coap/coap_message.cpp

@@ -275,6 +275,24 @@ exit:
     return error;
 }
 
+Error Message::AppendUriQueryOptions(const char *aUriQuery)
+{
+    Error       error = kErrorNone;
+    const char *cur   = aUriQuery;
+    const char *end;
+
+    while ((end = StringFind(cur, '&')) != nullptr)
+    {
+        SuccessOrExit(error = AppendOption(kOptionUriQuery, static_cast<uint16_t>(end - cur), cur));
+        cur = end + 1;
+    }
+
+    SuccessOrExit(error = AppendStringOption(kOptionUriQuery, cur));
+
+exit:
+    return error;
+}
+
 Error Message::AppendBlockOption(Message::BlockType aType, uint32_t aNum, bool aMore, otCoapBlockSzx aSize)
 {
     Error    error   = kErrorNone;

src/core/coap/coap_message.hpp

@@ -479,6 +479,18 @@ public:
      */
     Error ReadUriPathOptions(char (&aUriPath)[kMaxReceivedUriPath + 1]) const;
 
+    /**
+     * Appends a Uri-Query option.
+     *
+     * @param[in]  aUriQuery          A pointer to a null-terminated string.
+     *
+     * @retval kErrorNone         Successfully appended the option.
+     * @retval kErrorInvalidArgs  The option type is not equal or greater than the last option type.
+     * @retval kErrorNoBufs       The option length exceeds the buffer size.
+     *
+     */
+    Error AppendUriQueryOptions(const char *aUriQuery);
+
     /**
      * Appends a Block option
      *