From 9aabd7f813f82f4c7f1ed30fbbe45d7898d6b13c Mon Sep 17 00:00:00 2001
From: Giedrius <giedrius.medzevicius@gmail.com>
Date: Tue, 9 May 2017 22:56:59 +0300
Subject: [PATCH] Generic uint CoAP option support (#1736)

---
 include/openthread/coap.h     | 15 +++++++++++++
 src/core/api/coap_api.cpp     |  5 +++++
 src/core/coap/coap_header.cpp | 42 +++++++++++------------------------
 src/core/coap/coap_header.hpp | 14 ++++++++++++
 4 files changed, 47 insertions(+), 29 deletions(-)

diff --git a/include/openthread/coap.h b/include/openthread/coap.h
index 252294749..da0704303 100644
--- a/include/openthread/coap.h
+++ b/include/openthread/coap.h
@@ -257,6 +257,21 @@ void otCoapHeaderGenerateToken(otCoapHeader *aHeader, uint8_t aTokenLength);
  */
 ThreadError otCoapHeaderAppendOption(otCoapHeader *aHeader, const otCoapOption *aOption);
 
+/**
+ * This function appends an unsigned integer CoAP option as specified in
+ * https://tools.ietf.org/html/rfc7252#section-3.2
+ *
+ * @param[inout]  aHeader  A pointer to the CoAP header.
+ * @param[in]     aNumber  The CoAP Option number.
+ * @param[in]     aValue   The CoAP Option unsigned integer value.
+ *
+ * @retval kThreadError_None         Successfully appended the option.
+ * @retval kThreadError_InvalidArgs  The option type is not equal or greater than the last option type.
+ * @retval kThreadError_NoBufs       The option length exceeds the buffer size.
+ *
+ */
+ThreadError otCoapHeaderAppendUintOption(otCoapHeader *aHeader, uint16_t aNumber, uint32_t aValue);
+
 /**
  * This function appends an Observe option.
  *
diff --git a/src/core/api/coap_api.cpp b/src/core/api/coap_api.cpp
index 69e625c9f..66ea20d59 100644
--- a/src/core/api/coap_api.cpp
+++ b/src/core/api/coap_api.cpp
@@ -61,6 +61,11 @@ ThreadError otCoapHeaderAppendOption(otCoapHeader *aHeader, const otCoapOption *
     return static_cast<Coap::Header *>(aHeader)->AppendOption(*static_cast<const Coap::Header::Option *>(aOption));
 }
 
+ThreadError otCoapHeaderAppendUintOption(otCoapHeader *aHeader, uint16_t aNumber, uint32_t aValue)
+{
+    return static_cast<Coap::Header *>(aHeader)->AppendUintOption(aNumber, aValue);
+}
+
 ThreadError otCoapHeaderAppendObserveOption(otCoapHeader *aHeader, uint32_t aObserve)
 {
     return static_cast<Coap::Header *>(aHeader)->AppendObserveOption(aObserve);
diff --git a/src/core/coap/coap_header.cpp b/src/core/coap/coap_header.cpp
index d09f91a90..ec6add2a8 100644
--- a/src/core/coap/coap_header.cpp
+++ b/src/core/coap/coap_header.cpp
@@ -268,17 +268,17 @@ exit:
     return error;
 }
 
-ThreadError Header::AppendObserveOption(uint32_t aObserve)
+ThreadError Header::AppendUintOption(uint16_t aNumber, uint32_t aValue)
 {
     Option coapOption;
 
-    aObserve = Encoding::BigEndian::HostSwap32(aObserve & 0xFFFFFF);
-    coapOption.mNumber = kCoapOptionObserve;
+    aValue = Encoding::BigEndian::HostSwap32(aValue);
+    coapOption.mNumber = aNumber;
     coapOption.mLength = 4;
-    coapOption.mValue = reinterpret_cast<uint8_t *>(&aObserve);
+    coapOption.mValue = reinterpret_cast<uint8_t *>(&aValue);
 
-    // skip preceding zeros, but make sure mLength is at least 1
-    while (coapOption.mValue[0] == 0 && coapOption.mLength > 1)
+    // skip preceding zeros
+    while (coapOption.mValue[0] == 0 && coapOption.mLength > 0)
     {
         coapOption.mValue++;
         coapOption.mLength--;
@@ -287,6 +287,11 @@ ThreadError Header::AppendObserveOption(uint32_t aObserve)
     return AppendOption(coapOption);
 }
 
+ThreadError Header::AppendObserveOption(uint32_t aObserve)
+{
+    return AppendUintOption(kCoapOptionObserve, aObserve & 0xFFFFFF);
+}
+
 ThreadError Header::AppendUriPathOptions(const char *aUriPath)
 {
     ThreadError error = kThreadError_None;
@@ -314,33 +319,12 @@ exit:
 
 ThreadError Header::AppendContentFormatOption(MediaType aType)
 {
-    Option coapOption;
-    uint8_t type = static_cast<uint8_t>(aType);
-
-    coapOption.mNumber = kCoapOptionContentFormat;
-    coapOption.mLength = 1;
-    coapOption.mValue = &type;
-
-    return AppendOption(coapOption);
+    return AppendUintOption(kCoapOptionContentFormat, aType);
 }
 
 ThreadError Header::AppendMaxAgeOption(uint32_t aMaxAge)
 {
-    Option coapOption;
-
-    aMaxAge = Encoding::BigEndian::HostSwap32(aMaxAge);
-    coapOption.mNumber = kCoapOptionMaxAge;
-    coapOption.mLength = 4;
-    coapOption.mValue = reinterpret_cast<uint8_t *>(&aMaxAge);
-
-    // skip preceding zeros, but make sure mLength is at least 1
-    while (coapOption.mValue[0] == 0 && coapOption.mLength > 1)
-    {
-        coapOption.mValue++;
-        coapOption.mLength--;
-    }
-
-    return AppendOption(coapOption);
+    return AppendUintOption(kCoapOptionMaxAge, aMaxAge);
 }
 
 ThreadError Header::AppendUriQueryOption(const char *aUriQuery)
diff --git a/src/core/coap/coap_header.hpp b/src/core/coap/coap_header.hpp
index 5748cdbe8..389812249 100644
--- a/src/core/coap/coap_header.hpp
+++ b/src/core/coap/coap_header.hpp
@@ -273,6 +273,20 @@ public:
      */
     ThreadError AppendOption(const Option &aOption);
 
+    /**
+     * This method appends an unsigned integer CoAP option as specified in
+     * https://tools.ietf.org/html/rfc7252#section-3.2
+     *
+     * @param[in]  aNumber  The CoAP Option number.
+     * @param[in]  aValue   The CoAP Option unsigned integer value.
+     *
+     * @retval kThreadError_None         Successfully appended the option.
+     * @retval kThreadError_InvalidArgs  The option type is not equal or greater than the last option type.
+     * @retval kThreadError_NoBufs       The option length exceeds the buffer size.
+     *
+     */
+    ThreadError AppendUintOption(uint16_t aNumber, uint32_t aValue);
+
     /**
      * This method appends an Observe option.
      *